JP6000430B2 - Measurement data acquisition system, saddle-ride type vehicle equipped with measurement data acquisition system, method and computer program - Google Patents

Description

  The present invention relates to a stability control system applied to a saddle-ride type vehicle.

  Some motorcycles are equipped with a stable control technology represented by a traction control system and an anti-lock / brake system (hereinafter referred to as “ABS”). For example, in a traction control system, generally, the output of the engine is controlled by detecting the spin of the rear wheel, which is the driving wheel, from the difference in the wheel rotational speed between the front and rear wheels. Similarly, in the ABS, the brake is controlled using the wheel rotational speeds of the front and rear wheels.

  However, if the tire outer diameter changes from the design value due to replacement with a tire having a different diameter, wear, or the like, problems such as a misdetection of the rear wheel spin, inappropriate output suppression, and inappropriate ABS intervention timing may occur. For this reason, when certain conditions are met, the front and rear wheel rotation ratios are stored and used as calculation values as tire diameter correction values to prevent erroneous detection of rear wheel spin.

  Patent Document 1 relates to an ABS control technique. The technology of Patent Document 1 always detects the wheel speed difference between the front and rear wheels, and when the wheel speed difference is equal to or greater than a predetermined value for a predetermined time or longer, gradually changes one wheel speed to a predetermined range of the other wheel speed. Move closer to get inside. As a result, it is possible to suppress an unnecessary operation of the ABS due to an erroneous detection of the slip ratio or an inappropriate operation in which there is no intervention at a necessary timing.

  Patent Document 2 relates to a slip control technique when the vehicle is tilted. The technique of Patent Literature 2 holds tire characteristic data including a lateral radius of a tire, and controls braking / driving force by a function of the tire characteristic data and an inclination angle detected using an inclination sensor. As a result, it is possible to realize control in consideration of the situation where the slip signal is distorted due to the difference in the geometry of the front and rear wheels due to the inclination of the vehicle.

JP 2000-127940 A US Pat. No. 7,469,975

  To operate the traction control system and ABS more accurately, assuming that the actual wheel turning radius deviates from the design value of the tire diameter, the tire diameter at the tire contact point or the slip ratio (or slip amount) It is necessary to seek more correctly. For that purpose, it is necessary to correct the slip ratio (or slip amount) by learning the tire diameter using data at the time of running, and to operate the traction control system and ABS based on the correction value.

  The technique of Patent Document 1 described above relates to a technique for ABS. In Patent Literature 1, the speed difference between the front and rear wheels is approached in a situation where it is considered that tire slip does not occur during constant speed travel other than driving and braking. In this case, for example, learning is performed even when the vehicle is tilted and the ground contact point radius of the tire is changed, for example, when the vehicle runs on a loop bridge or a rotary. The resulting slip rate (or slip amount) may not be accurate.

  The technique of Patent Document 2 can be used for traction control and ABS. Patent Document 2 is a technique for correcting a change in the effective tire diameter caused by the inclination of the vehicle body and the tire profile, and is not intended to determine a condition for learning the tire diameter.

  Furthermore, the effective tire diameter corrected by the technique of Patent Document 2 may not be accurate. In Patent Literature 2, the value of the lateral radius of the tire when the tire is stationary is used as tire characteristic data. It is known that there is a difference in the cross-sectional shape (profile) of a tire between a dynamic shape during traveling and a static shape during stopping. In the control using the static value, it may be erroneously detected that the slip still occurs actually.

  The present invention provides a stable control system that can solve the above-described problems, and a saddle-ride type vehicle including the same.

A measurement data acquisition system according to the present invention is a measurement data acquisition system that acquires measurement data using a test vehicle having a first wheel and a second wheel, and is a first rotation speed of the first wheel. A wheel rotation speed sensor for acquiring the wheel rotation speed, a vehicle body speed sensor for acquiring the vehicle body speed of the test vehicle, an attitude detection unit for acquiring the bank angle of the vehicle body of the test vehicle, a predetermined bank angle, and a control An arithmetic unit that acquires measurement data indicating a relationship between the first wheel rotation speed and the vehicle body speed during traveling without applying power and driving force, and the measurement data is mounted on a predetermined vehicle. Thus, the predetermined vehicle is used to obtain the relationship between the rotational speed of the wheel of the predetermined vehicle and the vehicle body speed of the predetermined vehicle while the predetermined vehicle is traveling at the predetermined bank angle.
A measurement data acquisition system according to the present invention is a measurement data acquisition system that acquires measurement data using a test vehicle having a first wheel and a second wheel, and includes a first wheel and a second wheel. A wheel rotation speed sensor that acquires the first wheel rotation speed and the second wheel rotation speed, which are the respective rotation speeds, and the first wheel rotation speed and the first wheel rotation speed that are obtained during traveling without applying the driving force and the braking force. A computing unit that obtains at least the measurement data indicating the relationship with the two-wheel rotation speed according to the first wheel rotation speed, and the measurement data is mounted on the predetermined vehicle, whereby the first wheel of the predetermined vehicle When the rotational speed is given, it is used to obtain the relationship between the first wheel rotational speed and the second wheel rotational speed of the vehicle.

  According to the stable control system disclosed in the present application, since the slip ratio or the slip amount can be calculated more accurately, posture control such as traction control and anti-block brake control can be realized more stably.

It is a figure which shows the example of the stable control technique for controlling the attitude | position of a motorcycle. 1 is a diagram showing a configuration of a motorcycle 100 equipped with a traction control system that uses a slip amount. FIG. It is a figure which shows the basic procedure of a slip component calculation process. It is a figure which shows the more detailed procedure of the exemplary slip amount calculation process in this invention. It is a figure which shows an example of the procedure of a tire diameter learning process. It is a figure which shows an example of the procedure of the tire diameter learning process which considered the bank angle. It is a block diagram which shows the structure of the stable control system 110 by example embodiment. 3 is a control block diagram of a stable control system 110. FIG. It is a figure which shows the procedure of operation | movement of the stable control system. It is a figure which shows an example of the procedure of the tire diameter learning process using a tire expansion correction value. It is a figure which shows the plot result of the vehicle speed when sliding in the state which eliminated the influence of driving force, and the front-rear wheel speed ratio in the vehicle speed. FIG. 6 is a control block diagram of a stable control system 120 according to an exemplary embodiment 2. It is a figure which shows the procedure of operation | movement of the stable control system 120 by example Embodiment 2. FIG. It is a figure which shows the tire diameter correction value updated according to the learning result. It is a block diagram which shows the structure of the stable control system 130 by example Embodiment 3. FIG. 3 is a control block diagram related to the arithmetic unit 30 of the stability control system 130. FIG. It is a figure which shows the procedure of operation | movement of the stable control system. FIG. 10 is a control block diagram of an ECU 10 according to an exemplary fourth embodiment. (A)-(c) is a figure which shows the reference vehicle speed, bank angle (tilt angle), and the time series relationship of the correction value acquired by illustrative Embodiment 5. FIG. It is a block diagram which shows the structure of the stable control system 160 by example Embodiment 6. FIG. 2 is a control block diagram of a stable control system 160. FIG. It is a block diagram which shows the structure of the stable control system 170 by example Embodiment 7. FIG. 2 is a control block diagram of a stable control system 170. FIG. It is a figure which shows the grounding point A where a tire contacts the ground when a vehicle body is banked. It is a figure which shows slip (a)-(e) which may be included during driving | running | working. It is the plot figure of the data which measured the cross-sectional shape of the tire of a stationary state. It is a figure which shows the difference of the static cross-sectional shape and dynamic cross-sectional shape which the present inventors measured. FIG. 10 is a block diagram showing a configuration of a measurement data acquisition system 180 for a motorcycle 100 according to an exemplary embodiment 8. It is a figure which shows the procedure for the lean correction | amendment by illustrative Embodiment 8. FIG. FIG. 30 is a diagram showing the separation of slip components related to step S51 of FIG. 29. It is a figure which shows the measurement data regarding an expansion characteristic. It is the graph which simplified the measurement data of FIG. FIG. 30 is a diagram showing the separation of slip components related to step S52 of FIG. 29. It is a figure which shows the measurement data regarding the driving | running | working characteristic at the time of driving | running | working which applied driving force. It is the graph which simplified the measurement data of FIG. FIG. 30 is a diagram showing the separation of slip components related to step S53 of FIG. 29. It is a figure which shows the measurement data regarding the driving | running | working characteristic at the time of driving | running | working including the state which inclined the vehicle body. It is the graph which simplified the measurement data of FIG. (A) And (b) is a figure which shows the result of having measured the change rate of the effective diameter of a front-and-rear wheel. (A)-(c) is a figure which shows the implementation result of the lean correction | amendment of the slip amount in braking / driving force control.

  In the following, first, the cause of the above-described problems of the prior art will be described in more detail, and then an embodiment of a saddle-ride type vehicle according to the present invention will be described. In the present specification, the saddle riding type vehicle will be described as a motorcycle. However, this is an example. A vehicle having three or more wheels may be used.

In this specification, the terms “detection” and “acquisition” are used in principle as follows.
(1) “Detecting the physical quantity a” means obtaining information indicating the value (measured value) of the physical quantity a by measuring the physical quantity a.
(2) “Acquiring the physical quantity a” includes “detecting the physical quantity a” and includes determining the value of the physical quantity a based on information detected by a sensor or the like.

“Acquire” includes, for example, the following operations.
(2.1) Substituting the measured value into a predetermined arithmetic expression to calculate the value of the physical quantity a:
(2.2) Reading the value of the physical quantity a corresponding to the measurement value from the table or the like with reference to a table or database showing the correspondence between the measurement value and the physical quantity a:
(2.3) Estimating the value of physical quantity a from the measured value.

  For example, acquiring the yaw rate includes not only the case in which the yaw rate is directly detected by the yaw rate sensor but also the case in which the estimated value of the yaw rate is obtained by calculation from the output of another attitude angle sensor or speed sensor. The same applies to physical quantities other than the yaw rate, such as the bank angle.

  When the wheel speed is detected, a count value per unit time of an electric pulse output by a wheel speed sensor provided in the vicinity of the axle is usually used as the wheel speed. Although this count value is proportional to the wheel speed, since this proportional constant is not usually 1, the count value is not equal to the wheel speed value (tangential speed of the wheel outer peripheral surface) itself. However, in the equations for calculating the slip ratio λ and the slip amount, which will be described later, each term is a wheel speed. Therefore, if the proportional constant between the wheel speed and the count value in each term is set to an equal value, the count value is It may be handled as wheel speed.

  Now, in a stable control technology such as a motorcycle traction control system and ABS, it is common to use wheel rotational speeds of front wheels and rear wheels.

  For example, the slip ratio λ of the rear wheel during driving is typically expressed by the following equation. In some cases, the right side of the following formula is multiplied by 100 and expressed as a percentage.

λ = (V _r −V) / V _r

Further, the slip amount can be expressed by, for example, (V _r −V). Hereinafter, the slip ratio and the slip amount may be collectively referred to as a slip component.

Here, V is the vehicle body speed, and _Vr is the wheel speed of the rear wheel (drive wheel). In general, the “vehicle speed” is a moving speed of a motorcycle with respect to a road surface. The “wheel speed” is a tangential speed on the outer peripheral surface of the wheel when the wheel rotation axis is used as a reference. Wheel speed is proportional to "wheel rotation speed (number of rotations per unit time)" and "wheel rotation radius" and is generally expressed by the product of "wheel rotation angular speed" and "wheel rotation radius". The According to the above equation, when the vehicle body speed V is equal to the rear wheel speed V _r , the slip component is equal to zero.

  In order to obtain the wheel speeds of the front wheels and the rear wheels, the tire diameter is used as the wheel turning radius. The design value of the tire diameter is determined by the manufacturer. However, in reality, the actual turning radius of the wheel may deviate from the design value of the tire diameter due to changes in tire air pressure, changes in the ground contact point between the tire and the ground due to the inclination (bank) of the vehicle body, etc. is there. This can affect the calculation result of the slip ratio and / or the slip component (slip amount). Therefore, it is considered that there is room for accurately evaluating the deviation from the design value and improving the controllability.

  Here, the stable control technique will be described.

  FIG. 1 shows an example of a stable control technique for controlling the attitude of a motorcycle. As stability control techniques, for example, front wheel floating control, skid control, traction control, and antilock brake control are known. Among these, front wheel floating control, skid control, and traction control are technologies that control engine output (driving force) to prevent tire slipping and stabilize the vehicle body. On the other hand, the anti-lock brake control is a technique for maintaining the optimum braking force and steering performance at the same time by controlling the brake to maintain the slip ratio between the tire and the road surface within a predetermined range.

  In the traction control and the antilock brake control, the above-described slip component is calculated using the front wheel speed signal and the rear wheel speed signal. In the traction control, a correction amount for controlling the driving force is calculated based on the calculation result, and the engine ignition timing and the throttle target opening are set. As a result, the engine output can be controlled. On the other hand, in the anti-lock brake control, the operation and non-operation of the brake are switched at high speed so as to maintain the slip ratio within a predetermined range from the calculation result of the slip component. As a result, it is possible to secure the steering performance by preventing the tire from being locked while ensuring the optimum braking force.

  In this specification, the technique for calculating | requiring a slip component correctly is demonstrated. In the following, description will be given mainly using traction control as an example.

  FIG. 2 shows a configuration of the motorcycle 100 equipped with a traction control system using the slip amount. FIG. 3 shows a basic procedure of slip component calculation processing.

  First, as shown in FIG. 2, a motorcycle 100 that is a vehicle includes a vehicle body 1, a front wheel 2, and a rear wheel 3. A front wheel 2 is attached to the front portion of the vehicle body 1, and a rear wheel 3 is attached to the rear portion of the vehicle body 1. The vehicle body 1 is equipped with an engine 8 that generates driving force and front and rear wheel brakes 9 that generate braking force. The driving force of the engine 8 is controlled by the opening degree of the throttle 12 and the ignition timing by the spark plug 13. The braking force of the front and rear wheel brakes 9 is controlled by changing the brake pressure by operating the rider's brake lever or a braking / driving force adjusting unit described later. The engine 8 is assumed to operate on gasoline, but may be an electric motor. Any engine that generates a driving force may be used.

  The vehicle body 1 is provided with a controller 10 (hereinafter referred to as “ECU10”). In FIG. 2, the controller 10 is described at a position away from the vehicle body 1, but this is a convenient description for clarifying the input and output to the controller 10. Actually, the controller 10 is provided in the vehicle body 1.

  Further, the vehicle body 1 is provided with a reference vehicle speed sensor 11a and a wheel rotation speed sensor 11b. The reference vehicle speed sensor 11a is a sensor that detects vehicle speed information as a reference. The reference vehicle speed sensor 11a is a sensor that detects the rotational speed of the front wheels, for example. However, any sensor that can acquire the vehicle body speed may be used, and for example, a sensor that can acquire the vehicle body speed by GPS (Global Positioning System) may be used. Alternatively, the integrated value of the acceleration sensor may be acquired as the vehicle body speed. The wheel rotation speed sensor 11b is a sensor that detects, for example, the rotation speed of a rear wheel that is subject to tire diameter correction.

  The wheel of the front wheel 2 is provided with a front wheel speed sensor that detects the rotational speed (front wheel speed) of the front wheel 2. The wheel of the rear wheel 3 is provided with a wheel rotation speed sensor 11b that detects the rotation speed (rear wheel rotation speed) of the rear wheel 3. At the rear of the vehicle body 1, an attitude detection unit 11c that acquires the inclination angle (bank angle) of the vehicle body 1 is provided. For example, the posture detection unit 11c includes an angular velocity sensor and an acceleration sensor (both not shown), and an arithmetic circuit that acquires the posture information based on information output from the sensor. These will be described in detail later.

  Output signals of the reference vehicle speed sensor 11a, the wheel rotation speed sensor 11b, and the attitude detection unit 11c are given to the ECU 10.

  The process shown in FIG. 3 is executed in the following procedure. That is, when the ECU 10 receives information on the front wheel rotation speed and the rear wheel rotation speed, the ECU 10 calculates the wheel speeds of the front wheels and the rear wheels using the tire diameter design values. Next, the ECU 10 calculates the slip amount and / or the slip rate from the wheel speeds of the front wheels and the rear wheels. As described above, the slip amount is the difference between the wheel speeds of the rear wheels and the front wheels, and the slip ratio is obtained as the ratio of the wheel speeds of the rear wheels and the front wheels. Here, the speed of the front wheels, which are non-driving wheels, is regarded as the vehicle speed of the motorcycle. Thereby, the slip ratio can be obtained as λ described above. In this way, the controller acquires the slip amount or the slip rate.

  The ECU 10 adjusts the opening degree of the throttle 12 and the ignition timing by the spark plug 13 based on the acquired slip component and the bank angle information of the vehicle body 1 acquired by the attitude detection unit 11c, and an engine (not shown). ) Is controlled. This prevents the tire from slipping.

  The configuration of the motorcycle 100 shown in FIG. 2 is also referred to as appropriate in the description of the stability control system according to each embodiment described below.

  FIG. 4 shows a more detailed procedure of the slip amount calculation process in the present invention. FIG. 4 also shows tire diameter correction processes S1 and S2 and lean correction processes S3 and S4 performed in association with the slip amount calculation process. Processes S1 to S4 shown in FIG. 4 are processes unique to the present invention.

  As described above, the wheel speed calculation using the tire diameter design value is performed in the slip amount calculation process. If the obtained wheel speed is used as it is, an accurate slip component may not be obtained due to circumstances such as the tire diameter deviating from the design value. For this reason, the inventors of the present application have performed a tire diameter correction process after obtaining the wheel speed of the rear wheel to obtain a more accurate rear wheel speed. In addition, the object and timing which perform the tire diameter correction process in FIG. 4 are only examples. For example, the relationship between the front wheels and the rear wheels may be interchanged, and the tire diameter correction may be performed on the front wheels using the rear wheels as the reference vehicle speed. Alternatively, the tire diameter correction may be performed as two independent systems for the front wheels and the rear wheels, using the integrated values of the GPS and acceleration sensors as reference vehicle speeds.

  The ECU 10 learns the tire diameter in step S1 to obtain a correction value, and corrects the tire diameter in step S2. The timing for obtaining the correction value is during a period during which it is considered that no slip has occurred, for example, the vehicle continues to travel at a constant speed. However, the ECU 10 grasps the degree of the bank (bank angle) using, for example, the posture detection unit 11c in order to limit learning when the bank of the vehicle is generated. Learning refers to holding the rotation relationship between the front wheels and the rear wheels (for example, the relationship between the rotation speeds) as information. The correction value reflecting this rotational relationship is used to correct the front wheel rotation speed and / or the rear wheel rotation speed acquired during actual traveling. Since this correction value is updated even while the user is in the vehicle, a more accurate slip component can be calculated. In the above description, the reason why the rotational relationship between the front wheels and the rear wheels is given is that in the present embodiment, the wheel speed of the front wheels is regarded as the reference vehicle speed. More generally, learning means maintaining the relationship between the reference vehicle body speed and the wheel speed.

  By performing tire diameter correction, a more accurate slip amount can be obtained. However, when the vehicle body is banked at the time when the wheel speed is acquired, the slip amount includes an effect caused by the lean component that cannot be corrected by the tire diameter correction processing. Therefore, the inventors of the present application decided to suppress the influence caused by the lean component by performing the lean correction process.

  In step S3, the ECU 10 acquires bank angle information and estimates an apparent slip (lean component) at the bank angle. Information used as a basis for estimation is information required by the manufacturer in the development stage of the motorcycle. In an embodiment described later, how to acquire measurement data for estimating a lean component in the development stage of a motorcycle will be described.

  In step S4, the ECU 10 corrects the slip component by subtracting the estimated lean component from the calculated slip component. As a result, a more accurate slip component in which the influence of the lean component is corrected can be obtained.

  In the following, Embodiments 1 to 7 relating to tire diameter learning corresponding to Steps S1 and S2 described above, Embodiment 8 relating to lean correction corresponding to Steps S3 and S4, and a composite that performs tire diameter learning and lean correction A ninth embodiment will be described.

(Embodiment 1: Tire diameter learning using posture information (bank angle))
In the present embodiment, a technique for learning the relationship between the front wheel speed and the rear wheel speed in order to calculate an accurate slip component will be described.

  FIG. 5 shows an example of the procedure of the tire diameter learning process. The process indicated by the broken line in FIG. 5 is a process directly related to the tire diameter learning. All the processes in FIG. 5 are executed by the ECU 10 described above.

  The ECU 10 calculates the rotational speeds of the front wheels and the rear wheels from the front wheel pulses and the rear wheel pulses, which are vehicle speed signals, as shown in FIG. 5 at a timing when a predetermined condition is satisfied, and further rotates the rotational speeds of the front wheels and the rear wheels. To obtain the wheel speeds of the front and rear wheels. Then, the ECU 10 performs tire diameter learning using the obtained front and rear wheel speeds. The specific processing content of the tire diameter learning is, for example, to calculate a tire diameter correction value by calculating a ratio of front and rear wheel speeds. The ECU 10 obtains a tire diameter correction value obtained as a learning result, and corrects the rear wheel speed using the tire diameter correction value with the front wheel as a reference.

  The slip amount is calculated from the front wheel speed for control and the rear wheel speed for control calculated from the front wheel speed and the rear wheel speed after tire diameter correction.

  Next, the timing for performing the above-described tire diameter learning will be described.

  In order to learn the tire diameter, it is necessary to carry out in a state where the motorcycle stands upright at the time of running at a constant speed in a straight line. This is because if the vehicle body is inclined (banked), the ground contact radius (effective radius) of the tire changes depending on the bank. Therefore, the ECU 10 executes the tire diameter learning process assuming that the motorcycle is upright when the following conditions are satisfied.

(A) traveling in a certain vehicle speed range,
(B) There is no acceleration / deceleration, and (c) The condition (b) continues for a certain time or more while satisfying the condition (a).

  The above condition (a) assumes a medium speed range. This is because the vehicle speed calculation accuracy deteriorates at low and high speeds. The reason why the above condition (b) is provided is that a difference in rotational speed other than the tire diameter is observed during acceleration / deceleration.

  In a motorcycle, the timing at which the above three conditions are satisfied is not so many. For this reason, there are circumstances in which learning conditions are difficult to be satisfied and learning opportunities are reduced. Furthermore, for example, when going down a loop bridge, the above three conditions are satisfied, and the upright state may be erroneously estimated. As a result, tire diameter learning may be performed at the timing when the bank is generated.

  Therefore, the inventors of the present application provided the attitude detection unit 11c in the motorcycle 100 and learned the tire diameter according to the bank angle.

  FIG. 6 shows an example of the procedure of the tire diameter learning process considering the bank angle. As shown in the broken line part of FIG. 6, bank angle information is input for tire diameter learning. The ECU 10 performs tire diameter learning using front and rear wheel speeds obtained from front wheel pulses and rear wheel pulses, which are vehicle speed signals, according to the bank angle. The contents of the tire diameter learning are as described in relation to FIG.

The tire diameter learning “according to the bank angle” here means that, for example, when the bank angle is divided into a predetermined number of sections, the tire diameter learning is performed for each section. More specifically, it is assumed that the bank angle θ is assumed to have seven sections of θ _n ≦ θ <θ _n +10 degrees (θ _n = 0, 10, 20, 30, 40, 50, 60). In this case, “according to the bank angle” means that the tire diameter learning is performed for each section. However, the above description is only an example. Learning according to a finer section or angle may be performed, or learning according to a coarser section or angle may be performed. In the present specification, “depending on bank angle” may be described as “for each different bank angle” in the same meaning.

  Hereinafter, a specific configuration and operation for performing the above-described processing will be described.

  FIG. 7 is a block diagram showing the configuration of the stability control system 110 according to the present embodiment. Stability control system 110 changes the braking force or driving force of motorcycle 100 that is a vehicle having front wheels 2 and rear wheels 3.

  In the present embodiment, the stability control system 110 includes a reference vehicle speed sensor 11a, a wheel rotation speed sensor 11b, an attitude detection unit 11c, an ECU 10, and a braking / driving force adjustment unit 50.

  The reference vehicle speed sensor 11a is a sensor that is provided on the front wheel 2 and acquires the vehicle speed of the vehicle. The wheel rotation speed sensor 11b is a wheel rotation speed sensor that acquires the rear wheel rotation speed that is the rotation speed of the rear wheel.

  The posture detection unit 11 c acquires information (posture information) related to the posture of the vehicle body 1. Details will be described later.

  The ECU 10 is a so-called computer. In the present embodiment, the ECU 10 determines the rear wheel speed and the front wheel speed based on the vehicle body speed (front wheel speed in the present embodiment) and the rear wheel rotation speed under the traveling condition in which slip does not occur. A value indicating the relationship is calculated as a tire diameter correction value for each different bank angle. The “relation” here is, for example, a wheel speed ratio calculated from a ratio between a rear wheel speed and a front wheel speed. Furthermore, the ECU 10 calculates the wheel speed for control by correcting the rear wheel speed based on the tire diameter correction value corresponding to the current bank angle. Using this calculation result, the stability control system 110 can appropriately change the braking force or driving force of the motorcycle. In this specification, traction control, ABS, cruise control, and the like are collectively referred to as braking / driving force.

  Details of the components of the stable control system 110 will be described below.

  The posture detection unit 11 c includes an angular velocity sensor 21, an acceleration sensor 22, and a posture calculation unit 23.

  The angular velocity sensor 21 is, for example, a three-axis gyro sensor, and measures an angular velocity (angle / s) indicating a rotation amount per unit time for each of the yaw direction, the pitch direction, and the roll direction. That is, the angular velocity sensor 21 can detect the yaw angular velocity, the pitch angular velocity, and the roll angular velocity. The acceleration sensor 22 detects longitudinal acceleration, vertical acceleration, and lateral acceleration of the vehicle body 1 of the motorcycle 100.

  The posture calculation unit 23 uses the outputs from the angular velocity sensor 21 and the acceleration sensor 22 to acquire posture information. The attitude information is bank angle information obtained by using, for example, the yaw angular velocity. The posture information may include yaw angular velocity, longitudinal acceleration, and lateral acceleration information. The bank angle θ can be obtained by a known method using, for example, a Kalman filter.

  Next, the ECU 10 will be described.

  The ECU 10 includes a calculator 30 and a storage device 40.

  For example, the arithmetic unit 30 is a semiconductor integrated circuit called a CPU, and the storage device 40 is a semiconductor memory.

  The calculator 30 includes a learning permission condition determination unit 31, a tire diameter correction value calculation unit 32, a speed calculation unit 33, a control wheel speed calculation unit 34, and a braking / driving force control unit 35. Each of these components may be implemented as a hardware circuit, or a part or all of them may be regarded as a function realized by an operation of a CPU that executes an instruction based on software. The latter means that, for example, the arithmetic unit 30 that operates according to a flowchart showing the operation of the software described later functions as a learning permission condition determination unit 31 at a certain time and functions as a tire diameter correction value calculation unit 32 at another time. means. The specific operation of each component of the arithmetic unit 30 will be described in detail with reference to FIG.

  The storage device 40 stores information related to the tire diameter correction value.

  The braking / driving force adjusting unit 50 adjusts the braking / driving force of the motorcycle 100 by controlling the opening degree of the throttle 12, the ignition timing of the ignition plug 13, the brake, and the like based on the slip amount calculated by the ECU 10. .

  FIG. 8 is a control block diagram of the stable control system 110.

  First, the learning permission condition determination unit 31 determines whether a condition for permitting learning of the tire diameter is satisfied, and notifies the tire diameter correction value calculation unit 32 when the condition is satisfied. The condition permitting the learning of the tire diameter means that no tire slip has occurred. The learning permission condition determination unit 31 performs determination based on posture information (bank angle, acceleration, etc.), change amount of wheel rotation speed, brake pressure, accelerator operation, and the like.

Examples of learning permission conditions are as follows.
-Vehicle speed and / or acceleration / deceleration (acceleration) are within a predetermined range.

  When the learning permission condition is satisfied, the tire diameter correction value calculation unit 32 receives the posture information, the vehicle body speed, and the rear wheel vehicle speed, and the tire diameter based on the vehicle body speed and the rear wheel vehicle speed for each different bank angle. A correction value is calculated to correct

  For example, when the bank angle is substantially 0 degrees and the vehicle speed and acceleration / deceleration (acceleration) are within a predetermined range, the learning permission condition is satisfied. At this time, the vehicle body speed (front wheel speed) and the rear wheel speed are estimated to be the same. The tire diameter correction value calculation unit 32 calculates the vehicle body speed and the rear wheel speed obtained from the signals output from the reference vehicle speed sensor 11a and the wheel rotation speed sensor 11b and the design values of the tire diameters of the front and rear wheels. Find the ratio of. If the current tire diameter is equal to the design value, the ratio should be 1. However, if the tire diameter deviates from the design value, the ratio is not 1. Therefore, a coefficient for correcting the tire diameter is obtained so that the ratio becomes 1.

  For example, when the ratio is α (= rear wheel speed / vehicle speed), α is adopted as the tire diameter correction value C. The tire diameter design value for obtaining the rear wheel speed may be multiplied by 1 / α. Alternatively, the rear wheel speed determined using the tire diameter design value may be multiplied by 1 / α. Thus, the tire diameter or the rear wheel speed can be corrected so that the ratio becomes 1.

  The tire diameter correction value calculation unit 32 does not obtain the tire diameter correction value only when the bank angle is substantially 0 degrees. Even if the bank angle is not 0 degree, if the learning permission condition is satisfied, the tire diameter correction value calculating unit 32 sets the ratio of the vehicle body speed and the rear wheel speed to 1 at the bank angle. Find the diameter correction value. As a result, a correction value for each bank angle is acquired. The tire diameter correction value calculation unit 32 stores the obtained tire diameter correction value group in the storage device 40 as a tire diameter correction value table. An example of the correction value table is shown below.

  The tire diameter correction value calculation unit 32 performs the above calculation in the tire diameter correction value table update unit 32a. A ratio between the vehicle body speed and the rear wheel speed necessary for this is calculated by the multiplier 32c. The multiplier 32c receives the vehicle body speed (front wheel speed) and the rear wheel speed obtained from the reference vehicle speed sensor signal and the wheel rotational speed sensor signal by the speed calculator 33, calculates the ratio thereof, and calculates the tire diameter. It is sent to the correction value table updating unit 32a.

  The storage device 40 holds at least two tire diameter correction value tables. FIG. 8 holds two tire diameter correction value tables, that is, the previous tire diameter correction value table 40a and the current tire diameter correction value table 40b. The reason for holding at least two tire diameter correction value tables is that if the learning permission condition is not satisfied, the tire diameter correction value at that bank angle cannot be obtained, so the previously obtained tire diameter correction value at that bank angle is used. It is to do.

  The tire diameter correction value calculation unit 32b receives the current posture information (bank angle) and obtains a tire diameter correction value at the bank angle.

  The control wheel speed calculation unit 34 divides the rear wheel vehicle speed obtained by the speed calculation unit 33 by the tire diameter correction value, in other words, multiplies the inverse of the tire diameter correction value to correct the rear wheel vehicle speed.

  The braking / driving force control unit 35 calculates the slip amount based on the corrected rear wheel vehicle speed and the vehicle body speed.

  FIG. 9 shows an operation procedure of the stable control system 110.

  In step S11, the speed calculation unit 33 receives the wheel rotation speed sensor signal and the reference vehicle speed sensor signal. And the speed calculating part 33 acquires a wheel speed from a wheel rotational speed sensor signal, and acquires a reference vehicle body speed from a reference vehicle body speed sensor signal.

  In step S12, the multiplier 32c acquires the wheel speed ratio from the ratio between the wheel speed and the reference vehicle body speed. In step S13, the tire diameter correction value table update unit 32a acquires the previous tire diameter correction value table from the storage device 40. In step S14, the tire diameter correction value table update unit 32a acquires posture information from the posture detection unit 11c.

  In step S15, the tire diameter correction value table updating unit 32a determines a learning permission condition. In step S16, when the determination result indicates “permitted”, the process proceeds to step S17, and when “not permitted” is illustrated, the process proceeds to step S18.

  In step S17, the tire diameter correction value table updating unit 32a updates the value corresponding to the acquired posture information in the tire diameter correction value table to the value of the wheel speed ratio. The data to be updated is held in a memory (not shown) such as an internal register of the tire diameter correction value table update unit 32a.

  In step S18, the tire diameter correction value table updating unit 32a maintains the previous tire diameter correction value table without updating it. This is because the learning permission condition is not satisfied and it is not appropriate to update the tire diameter correction value.

  In step S19, the tire diameter correction value calculation unit 32b extracts a value corresponding to the acquired posture information from the tire diameter correction value table and adopts it as a tire diameter correction value.

  In step S20, the tire diameter correction value table updating unit 32a stores the tire diameter correction value table in the storage device 40 as a “current tire diameter correction value table”.

  In step S21, the control wheel speed calculation unit 34 corrects the wheel speed with the extracted tire diameter correction value, and acquires the control wheel speed.

  In step S22, the braking / driving force control unit 35 controls the braking / driving force based on the control wheel speed.

  Through the above processing, an appropriate tire diameter correction value corresponding to the current bank angle is selected and extracted in both cases where the learning permission condition is satisfied and when the learning permission condition is not satisfied, and is used for controlling the braking / driving force. The As a result, appropriate intervention such as a traction control system and ABS is realized at a more appropriate timing. For example, when the motorcycle 100 is going down a loop bridge, the vehicle body 1 has a certain bank angle, and a tire diameter correction value corresponding to the bank angle is acquired. On the other hand, when the motorcycle 100 is traveling at a bank angle of 0 °, a tire diameter correction value corresponding to the bank angle of 0 ° is acquired. Since the tire diameter correction value acquired previously is selected and adopted according to the bank angle of the running motorcycle 100 and used to calculate the wheel speed for control, an appropriate traction control system, ABS, etc. Intervention is realized.

  Note that the order of the steps in FIG. 9 is an example. For example, steps S13 and S14 may be inserted between steps S11 and S12, or steps S11 and S12 may be performed after steps S13 and S14. Further, for example, the processing of storing the tire diameter correction value table in the storage device 40 in step S20 can be performed independently of steps S19, S21, and S22, and therefore the position of step S20 can be changed. Step S20 may be performed each time steps S17 and S18 are completed, for example.

(Embodiment 2: Tire diameter learning considering tire expansion)
In the present embodiment, a tire diameter learning process in consideration of tire expansion that may affect the tire diameter will be described.

  The inventors of the present application have noticed the need for tire diameter correction in consideration of factors that may affect the tire diameter, independent of consideration of the posture information according to the first embodiment. That is, it is a change in the tire diameter due to the tire expansion increasing with the vehicle body speed. Tire expansion occurs under the influence of centrifugal force applied in the radial direction from the center of the tire. The inventors of the present application have found that, for example, it is not always appropriate to make the tire diameter correction value when learning at 50 km / h and the tire diameter correction value when learning at 150 km / h the same. I came to get.

  Tire diameter correction in consideration of tire expansion is particularly necessary when the motorcycle 100 has a high vehicle speed. For example, in the first embodiment, the learning permission condition is that the vehicle body speed or the like falls within a certain range. Therefore, when the vehicle body speed exceeds the certain range, it is necessary to perform learning on the basis independent of the posture information.

  In addition, it is difficult to specify the change of the tire diameter due to the tire expansion by the tire profile or the like when stationary. The inventors of the present application determined the tire diameter correction value from the relationship of the vehicle speeds of the front and rear wheels according to the speed range.

  FIG. 10 shows an example of the procedure of the tire diameter learning process using the tire expansion correction value. Three processes indicated by broken lines are unique processes related to the present embodiment.

  As indicated by the broken line in FIG. 10, an expansion correction value is acquired according to the value of the vehicle body speed (front wheel speed), and the expansion correction value is used for the tire diameter learning process and the process for reflecting the expansion correction value. Has been.

  Hereinafter, a method for determining the expansion correction value will be described.

  FIG. 11 shows a plot result of the vehicle speed when the vehicle slides without the influence of the driving force and the front and rear wheel speed ratio at the vehicle speed. The state in which the influence of the driving force is eliminated means that the clutch is turned off. The vehicle speed was set to a predetermined value or more.

  FIG. 11 also shows a straight line L that best represents the plot results. The straight line L shows that the front-rear wheel speed ratio changes according to the speed even when the influence of the driving force is eliminated. A positive slope of the straight line L indicates that the degree of tire expansion changes according to the vehicle body speed, and the tire diameter is changed.

  FIG. 11 will be described using the straight line L as an example.

  When the vehicle speed is 0, the tire diameter correction value represented by rear wheel speed / front wheel speed is C0. On the other hand, when the vehicle speed is about 100 km / h, the front / rear wheel speed ratio when sliding without the influence of the driving force can be expressed as about C0 + 0.005. Then, it was found that the front / rear wheel speed ratio when the vehicle was slid with the influence of the driving force eliminated at a vehicle speed of about 160 km / h can be expressed as about C0 + 0.01.

  This specification assumes that the tire diameter correction value C0 is in the vicinity of 1. According to the results of trials by the inventors of the present application, the tire diameter correction value C0 when the vehicle speed is 0 is well distributed in the range of 0.96 to 1.00. The reason why the numerical value fluctuates in this way is considered to be because, for example, the type of tires worn during traveling has changed. In the present specification, at least the above-mentioned range of 0.96 to 1.00 is a category in the vicinity of 1.

  Based on the above results, the inventors of the present application concluded that the tire diameter correction value increased by 0.005 at about 100 km / h and increased by 0.01 at about 160 km / h due to the influence of tire expansion. I attached. Then, by using the straight line L, the tire inflation correction value (Q) at a specific speed is determined. In other words, for example, the tire inflation correction value is set to 0.005 at about 100 km / h, and the tire inflation correction value is set to 0.01 at about 160 km / h.

  With the above method, the “expansion correction value acquisition” processing shown in FIG. 10 is realized. The tire inflation correction value may be held for each predetermined unit of vehicle speed (for example, for each unit of 1 km / h).

  Next, the tire diameter learning process in FIG. 10 will be described.

  In the present embodiment, the tire diameter correction value (C0) at 0 km / h is a learning target. The tire diameter correction value (C0) is obtained as a value obtained by subtracting the tire expansion correction value at the vehicle speed from the front and rear wheel speed ratio at a certain vehicle speed. The tire diameter correction value (C0) at 0 km / h corresponds to the intercept of the straight line L in FIG. In other words, the tire diameter correction value (C0) at 0 km / h is considered to be the same regardless of the vehicle speed. Note that tire diameter correction values (C0) acquired at a plurality of vehicle speeds may be different. Therefore, a tire diameter correction value (C0) is obtained by averaging the tire diameter correction values obtained one after another according to the vehicle speed. ) May be adopted.

  By the tire diameter learning process described above, a tire diameter correction value (C0) at 0 km / h can be obtained.

  Next, the tire diameter / expansion correction value reflecting process in FIG. 10 will be described. This process is an addition operation of the tire diameter correction value (C0) at 0 km / h obtained by learning and the tire expansion correction value (Q) specified from the current vehicle speed. A value (C0 + Q) obtained by this addition operation is used as a tire diameter correction value at the vehicle speed.

  FIG. 12 is a control block diagram of the stable control system 120 according to the present embodiment for executing the above-described processing. The difference between the control block diagram of FIG. 12 and the control block diagram of FIG. 8 is that, in FIG. 12, the tire diameter correction value table update unit 32a receives reference vehicle speed information and does not receive posture information. The difference between the two processes is that the tire diameter correction value table updating unit 32a in FIG. 12 performs three processes indicated by broken lines in FIG. 10 instead of the process in FIG. That is, the tire diameter correction value table updating unit 32a performs a tire expansion correction value acquisition process, a tire diameter correction value (C0) acquisition process at 0 km / h, and a tire diameter / expansion correction value reflection process. is there. However, since the processing is as described above, its details are omitted.

  FIG. 13 shows an operation procedure of the stability control system 120 according to the present embodiment. The same steps as those in FIG. 6 are denoted by the same step numbers and description thereof is omitted. Hereinafter, steps S31 to S35 will be described.

  First, in step S31, the wheel speed and the reference vehicle speed are acquired, which is the same as the process in FIG. Here, the reference vehicle speed information obtained from the reference vehicle speed sensor 11a is also transmitted to the tire diameter correction value table updating unit 32a.

  Step S14 in FIG. 9 does not exist in FIG. For this reason, the elements of the posture information are not used for the determination of the learning permission condition in steps S32 and S33. As the learning permission condition, for example, it is determined whether the driving force and the braking force are not sufficiently affected, or whether the vehicle body speed is equal to or higher than a predetermined threshold (for example, 20 km / h).

  In step S34, the tire diameter correction value table updating unit 32a acquires a tire expansion correction value at the vehicle speed that is held in advance from the front and rear wheel speed ratio. Then, the tire inflation correction value is subtracted from the front / rear wheel speed ratio. The tire diameter correction value table updating unit 32a holds the obtained value as a tire diameter correction value (C0) at 0 km / h.

  In step S35, the tire diameter correction value table updating unit 32a adds the tire diameter correction value at 0 km / h and the tire expansion correction value at the current reference vehicle body speed, and adopts it as the tire diameter correction value.

  By the above processing, tire diameter correction processing is realized in which the influence of tire diameter expansion corresponding to the vehicle speed is reduced.

  In the present embodiment, only tire expansion is considered in correcting the tire diameter. However, as described in the first embodiment, posture information may be further considered. Since the vehicle body 1 of the motorcycle 100 can bank when traveling at a high speed, it is more preferable to acquire the tire diameter correction value in consideration of the bank angle.

(Embodiment 3: Improving the speed of tire diameter learning immediately after power activation)
In the present embodiment, a tire diameter learning process relating to the speed at which the tire diameter is learned will be described.

  More specifically, it is assumed that the rider has started a motorcycle and started running. In the present embodiment, the learning speed of the correction value is changed according to the elapsed time from the startup or the travel distance from the startup. More specifically, in the present embodiment, the time when the rider turns the key and energizes the motorcycle when starting (starting point), when the elapsed time from the starting point is less than a predetermined threshold, Alternatively, when the accumulated travel distance from the starting point is equal to or less than a predetermined threshold, the tire diameter learning update step (change amount before and after the update) is increased. By increasing the learning update step relatively early from the start, the learning result can be reflected in the control as soon as possible. As a result, the rider can grasp the behavior of the motorcycle 100 as desired, and can enjoy driving the motorcycle 100 with improved controllability.

  Referring to FIG. 14, an update mode of the tire diameter correction value realized in the present embodiment will be described.

  FIG. 14 shows the tire diameter correction value updated in accordance with the learning result. The waveform (1) in the figure shows the ratio of the front wheel rotation speed and the rear wheel rotation speed during traveling. Waveform (2) shows the tire diameter correction value updated over time. At startup, the last value that was used when the power was cut off the most recently is used. Waveform (3) shows the correction value update condition.

  As understood from FIG. 14, the change in the tire diameter correction value shown as the waveform (2) is relatively large during the fixed period T starting from the power activation of the motorcycle 100, and after the fixed period T has elapsed. The tire diameter correction value changes relatively little.

  This difference means that the range in which the variation of the tire diameter correction value is allowed in one process is different. In the present embodiment, the range in which the tire diameter correction value before the update can be changed from the previous value is provided with different restrictions depending on whether the predetermined period T has elapsed or after. The changeable range is relatively large before the fixed period T elapses, and the changeable range is limited to be relatively small after the fixed period T elapses. The significance of providing the changeable range is to prevent the tire diameter correction value from changing suddenly in a single process. While providing such a restriction, a difference is provided in the degree of change in the tire diameter correction value depending on whether or not the predetermined period T has elapsed. The fluctuation range (X1) before the lapse of the fixed period T in FIG. 14 is set larger than the fluctuation range (X2) after the lapse of the fixed period T.

  For example, it is assumed that the tire diameter correction value stored in a storage device such as a memory and the wheel speed ratio calculated from the current wheel speed information are greatly different. It is necessary to update the tire diameter correction value to catch up with the current wheel speed ratio by learning. However, since the range in which the tire diameter correction value can move in one process is limited, the update is performed in multiple steps. At this time, since the range in which the tire diameter correction value can be changed is relatively large before the lapse of the predetermined period T, the tire diameter correction value is set to the current wheel speed ratio earlier, that is, with less learning. catch up. Note that, after the predetermined period T has elapsed, the changeable range of the tire diameter correction value is set to be relatively small, but the tire diameter correction value has caught up with the current wheel speed ratio by that time period, or Since the tire diameter correction value is close to the current wheel speed ratio, there is no problem that the changeable range of the tire diameter correction value is relatively small.

  By changing the value of the range in which the tire diameter correction value can be changed in one process (learning update step), it is possible to change the time until the learning catches up (the number of necessary processes). This makes it possible to change the learning speed.

  Increasing the allowable range (step) of the change in the tire diameter correction value allows the tire diameter correction value to converge at an early stage. Therefore, it is possible to obtain an appropriate slip amount and slip rate at an early stage, and it is possible to operate the traction control and the ABS at an appropriate timing and intervention amount. However, if the allowable width (step) of the change in the tire diameter correction value is too large, the control amount may change abruptly and adversely affect riding comfort. Therefore, an upper limit of X1 or X2 is provided as an allowable range (step) of change in the tire diameter correction value so as not to be extremely large.

  In FIG. 14, the reason why the correction value update condition is not satisfied is indicated by a balloon for reference.

  FIG. 15 is a block diagram showing a configuration of the stability control system 130 according to the present embodiment.

  15 differs from FIG. 7 in that an elapsed time calculation unit 36 and a travel distance calculation unit 37 are newly provided in the calculator 30 and a clock circuit 45 is newly provided. As will be described later, the internal configuration of the tire diameter correction value calculation unit 32 that receives signals from the elapsed time calculation unit 36 and the travel distance calculation unit 37 is also changed. Although not shown in FIG. 7, the configuration of FIG. 7 is naturally provided with a clock circuit for operating the CPU as the computing unit 30. The clock circuit may be the clock circuit 45, or a separately provided clock circuit may be the clock circuit 45. For convenience of explanation, the elapsed time calculation unit 36 and the travel distance calculation unit 37 are provided, but either one may be provided.

  The clock circuit 45 generates a clock signal for counting time. In the present embodiment, clock circuit 45 generates a clock signal from the time point when motorcycle 100 is powered on.

  The elapsed time calculation unit 36 counts and holds the elapsed time using the clock signal output from the clock circuit 45.

  The travel distance calculation unit 37 calculates the travel distance from the time when the power of the motorcycle 100 is turned on.

  FIG. 16 is a control block diagram relating to the arithmetic unit 30 of the stability control system 130. FIG. 16 shows only a portion particularly relevant to the present embodiment, and the other configuration is shown by partially simplifying the configuration of FIG.

  The elapsed time calculation unit 36 includes a pulse count unit 36a and a time count unit 36b. The pulse count unit 36 a counts pulses of the clock signal output from the clock circuit 45. The time counting unit 36b converts the number of pulses counted by the pulse counting unit 36a into time. For example, assume that the clock circuit 45 operates at fHz. When the number of pulses counted by the pulse counting unit 36a reaches f, the time counting unit 36b counts one second. Since the counting of pulses starts from the time when the power of the motorcycle 100 is turned on, the time counted by the time counting unit 36b means the elapsed time from the time when the power of the motorcycle 100 is turned on.

  The travel distance calculation unit 37 includes a pulse signal integration unit 37a and a travel distance count unit 37b. The pulse signal integration unit 37a receives and integrates (counts) the pulses of the wheel rotation speed sensor signal from the rear wheels. The travel distance counting unit 37b converts the number of pulses counted by the pulse signal integrating unit 37a into a distance. For example, it is assumed that the wheel rotation speed sensor signal pulse is generated N times per tire rotation. The pulse count unit 36a accumulates the number of pulses. It means that the rear wheel has rotated k times when the number of pulses becomes N · k. The travel distance counting unit 37b calculates a value obtained by multiplying the outer periphery of the tire of the rear wheel by k. This value is the distance from the start of counting the pulses of the wheel rotational speed sensor signal, that is, the distance from the start of traveling.

  The tire diameter correction value calculation unit 32 includes a learning update step calculation unit 32d. The learning update step calculation unit 32 d receives information on elapsed time from the elapsed time calculation unit 36 and receives information on travel distance from the travel distance calculation unit 37. Based on the information, the learning update step calculating unit 32d determines whether the elapsed time from when the motorcycle 100 is turned on is equal to or less than a predetermined time value, or the distance from the start of traveling. It is determined whether the distance value is equal to or less than a predetermined distance value. When it is less than or equal to a predetermined time value and / or less than or equal to a predetermined distance value (generally described as “when it is equal to or less than a threshold”), the learning update step calculation unit 32d changes the learning update step. . The learning update step means an allowable range (step) in which the tire diameter correction value changes toward the convergence value of the learning result (tire diameter correction value). That is, the learning update step calculation unit 32d increases the learning speed by increasing the step when the threshold is less than or equal to the above threshold, and decreases the learning speed by decreasing the step when it is not less than or equal to the threshold. A specific description will be given later with reference to FIG.

  The tire diameter correction value calculation unit 32 includes a tire diameter correction value update unit 32e. The function of the tire diameter correction value update unit 32e is substantially the same as that of the tire diameter correction value table update unit 32a shown in FIG. The update target of the tire diameter correction value table updating unit 32a is a correction value table, whereas the update target of the tire diameter correction value update unit 32e is one correction value.

  FIG. 17 shows an operation procedure of the stability control system 130. In the present embodiment, it is assumed that learning is performed once when the processing from start (START) to end (RETURN) shown in FIG. 17 is performed once. The same steps as those in FIG. 9 are denoted by the same step numbers, and description thereof is omitted. Steps S15 and S20 are given more specific conditions, but are not particularly explained because they are clear from the description.

  In step S41, the elapsed time calculation unit 36 calculates the elapsed time from the clock signal, and the travel distance calculation unit 37 calculates the travel distance from the wheel rotation speed sensor signal.

  In step S42, the learning update step calculation unit 32d compares whether the elapsed time and / or the travel distance is equal to or less than a threshold value.

  In step S43, when the comparison result is equal to or smaller than the threshold, the process proceeds to step S44, and when larger than the threshold, the process proceeds to step S45.

  In step S44, the learning update step calculation unit 32d sets the learning update step to the set value 2. On the other hand, in step S45, the learning update step calculation unit 32d sets the learning update step to the set value 1. In the present embodiment, it is assumed that setting value 1 <setting value 2. By setting in this way, the learning speed can be changed.

  In step S46, the learning update step calculation unit 32d obtains a difference (A) between the previous tire diameter correction value and the wheel speed ratio value acquired from the multiplier 32c, and the difference (A) and the learning update step (B ).

  In step S47, if the comparison result is A ≦ B, the process proceeds to step S48, and if the comparison result is A> B, the process proceeds to step S49.

  In step S48, the tire diameter correction value updating unit 32e updates the tire diameter correction value with the acquired wheel speed ratio.

  On the other hand, in step S49, the tire diameter correction value update unit 32e updates the tire diameter correction value close to the wheel speed ratio acquired within the width of the learning update step. For example, the tire diameter correction value update unit 32e brings the tire diameter correction value close to the wheel speed ratio by the width of the learning update step that is the maximum value.

  With the above processing, a difference in learning (update) speed as shown in FIG. 14 is provided, and the tire diameter correction value can be converged as early as possible.

  In the above description, the example in which the tire diameter correction value is updated with the width of the learning update step as the upper limit value and approaches the wheel speed ratio has been described. Regarding the width of this learning update step, a minimum width (lower limit value) may be provided. In this case, the learning update step calculation unit 32d obtains a difference (A) between the previous tire diameter correction value and the front / rear wheel speed ratio value acquired from the multiplier 32c, and the difference (A) is an upper limit value and a lower limit value. (B), the current front / rear wheel speed ratio is adopted as a new tire diameter correction value. On the other hand, if the difference (A) does not fall between (B) between the upper limit value and the lower limit value, the learning update step calculation unit 32d changes the tire diameter correction value by an upper limit value or a lower limit value. This is adopted as a new tire diameter correction value.

(Embodiment 4: Decrease the speed of tire diameter learning during incline)
In the present embodiment, a tire diameter learning process relating to the speed at which the tire diameter is learned will be described.

  Assume a situation where a rider is running on a motorcycle and the vehicle body is banking. In the present embodiment, the correction value update speed is changed according to the value of the posture information. More specifically, in the present embodiment, the tire diameter learning update step is reduced while the vehicle body is banking.

  The configuration of the stable control system according to the present embodiment is as shown in FIG. However, the configuration of the ECU 10 as a part thereof is different from the configuration of the stable control system 110 according to the first embodiment (FIG. 8). Hereinafter, the configuration of the ECU 10 of the stable control system according to the present embodiment will be described with reference to FIG.

  FIG. 18 is a control block diagram of the ECU 10 according to the present embodiment.

  18 differs from FIG. 8 in that a learning update step calculation unit 32d is newly provided in the computing unit 30, and a tire diameter correction value update unit 32e is used instead of the tire diameter correction value table update unit 32a. It is provided.

  Similar to the function described in the third embodiment, the learning update step calculation unit 32d has a function of adjusting the learning speed using the set value. More specifically, the learning update step calculating unit 32d receives the posture information of the vehicle body and changes the update speed of the correction value according to the value of the posture information. In the present embodiment, while the vehicle body 1 of the motorcycle 100 is traveling at an inclination, the learning update step calculation unit 32d uses a setting value that slows the learning speed. On the other hand, while the vehicle body 1 of the motorcycle 100 is traveling without being tilted, the learning update step calculating unit 32d increases the learning speed. As an example, the state where the vehicle body 1 is tilted is, for example, that the bank angle is The state outside the range of ± 10 ° means the state where the vehicle body 1 is not inclined means the state where the bank angle is within the range of ± 10 °, for example. This is because it is easy to improve the accuracy of learning during the period when the vehicle is running in an almost upright state.

  The flowchart showing the operation procedure of the stable control system according to the present embodiment is the same as the flowchart shown in FIG. 17 except for some differences. The difference is that FIG. 17 includes processing (steps S42 to S45) related to calculation and comparison of elapsed time and travel distance, but these are not necessary in the present embodiment. Instead of these processes, the learning update step calculation unit 32d calculates the learning update step according to the process of acquiring the attitude information of the vehicle body 1 from the attitude detection unit 11c, the value of the attitude information, that is, the magnitude of the bank angle. It is only necessary that the processing to be included is included.

  Through the above processing, the tire learning speed is reduced during the slope, so that learning in a situation where accuracy is difficult to ensure is suppressed. As a result, learning can be performed even while the vehicle is tilted, and the possibility that the learned value will be applied even during upright running can be reduced.

(Embodiment 5: Tire diameter learning is performed when standing upright)
In the fourth embodiment, the example in which the tire diameter learning speed is reduced while the vehicle body is banking has been described. Unlike the fourth embodiment, a learning schedule may be considered in which tire diameter learning is not performed while banking. In other words, a learning schedule in which the tire diameter learning is performed only during a period in which the motorcycle is running substantially upright can be considered. In the present embodiment, “substantially upright” means a state where the bank angle is within a range of ± 10 °, for example.

  In the processing according to the present embodiment, the learning update step calculation unit 32d shown in FIG. 18 according to the fourth embodiment acquires the posture information of the vehicle body 1 from the posture detection unit 11c, and the bank angle is increased from the posture information. Only when it is determined that the distance is within the range of ± 10 °, the setting value for calculating the learning update step is used, and when the value exceeds the range, the setting value is set such that the learning update step is 0. It is only necessary that the processing to be included is included.

  FIGS. 19A to 19C show a time series relationship between the reference vehicle speed, the bank angle (tilt angle), and the acquired correction value according to the present embodiment. (A) shows a reference vehicle speed (front wheel speed), (b) shows an inclination angle, and (c) shows an acquired correction value. The learning permission condition in this example is an almost upright state, the rear wheel speed and the reference vehicle speed are equal to or higher than the threshold value, and the amount of change between the wheel speed and the reference vehicle speed is smaller than a predetermined value. The tire diameter correction value was obtained by correcting the wheel speed ratio with a value obtained as a function of the reference vehicle speed and the driving force.

  FIG. 19C shows two correction values, a solid line and a one-dot chain line. Of these, the tire diameter correction value learned by determining that the solid line is almost upright using posture information, and the one-dot chain line is the correction learned by determining only other conditions without using posture information Value.

  From FIG. 19B and FIG. 19C, it can be read that there is no mislearning by determining whether or not the position sensor information (bank angle) is generally upright. The correction value indicated by the solid line does not change during the period when the bank angle shown in FIG. 19B is changing. This means that tire diameter learning is not performed. When the time is 0, the correction value is slightly high. This is because the correction value learned last time is maintained. Thereafter, the correction value gradually decreases and shows a constant value. This constant value is a correction value for corresponding to the state where the tire is replaced.

  On the other hand, the correction value indicated by the alternate long and short dash line in FIG. 19C also changes during the period in which the bank angle shown in FIG. That is, it is understood that the tire diameter learning is performed. For example, pay attention to the period D. The period D is a period in which the vehicle travels while being inclined at a constant vehicle speed. Since the learning result indicated by the one-dot chain line in FIG. 19C does not use posture information, it is determined that the learning condition is satisfied despite the inclination, and the correction value is the value up to that point. To higher values. This is learning performed in a situation where learning should not be performed, that is, erroneous learning.

  As described above, in the present embodiment, the tire diameter correction value in a substantially upright state is calculated and stored using the posture information. Compared to the case where the tire diameter is learned without using the posture information, an appropriate tire diameter correction value can be acquired. Therefore, it is appropriate when determining whether to intervene traction control, ABS, or the like. A slip amount or a slip ratio can be calculated.

  Note that the term “mislearning” in the above description only means that the learning condition in the present embodiment is not satisfied. Whether or not the learning condition in this embodiment is successful matches the suitability as a general learning condition is not particularly a problem. For example, even if the learning condition in the present embodiment is not satisfied, for example, as described in the first embodiment, a process of performing tire diameter learning for each bank angle can be assumed.

(Sixth embodiment: variation of learning permission condition)
In the present embodiment, a modified example related to the learning permission condition will be described. Specifically, the learning is performed when the braking / driving force is less than the threshold value, when the change amount of the wheel speed and / or the reference vehicle speed is less than the threshold value, or when the wheel speed and / or the reference vehicle speed is within the threshold range. Do.

  FIG. 20 is a block diagram showing the configuration of the stability control system 160 according to the present embodiment.

  FIG. 20 differs from FIG. 7 in that a sensor group 60 is newly provided and a braking / driving force calculation unit 38 and a change amount calculation unit 39 are newly provided in the calculator 30.

  The sensor group 60 includes a plurality of sensors. In the present embodiment, a brake pressure sensor 60a, an accelerator opening sensor 60b, and an engine rotation sensor 60c are illustrated. The brake pressure sensor 60a is a sensor that detects a brake pressure. The accelerator opening sensor 60b is a sensor that detects the opening of the accelerator. The engine rotation sensor 60c is a sensor that detects the engine speed. The sensors that can be included in the sensor group 60 are not limited to these.

  The braking / driving force calculation unit 38 and the change amount calculation unit 39 will be described with reference to FIG.

  FIG. 21 is a control block diagram of the stability control system 160.

  The braking / driving force calculation unit 38 obtains information on the brake pressure, the accelerator opening, and the engine speed from the brake pressure sensor 60a, the accelerator opening sensor 60b, and the engine rotation sensor 60c, respectively. The braking / driving force calculation unit 38 calculates the braking force and the driving force currently applied to the vehicle body based on these signals.

The value indicating the braking force obtained by calculation is, for example,
Fb = 2μ × P × A × r / R
It can be expressed as. The meaning of each symbol is as follows.
Fb: braking force μ: coefficient of friction between brake pad and disk P: hydraulic pressure A: brake caliper cylinder area r: brake effective diameter R: tire diameter

  Strictly speaking, the friction coefficient μ depends on temperature or the like, but if a representative value is adopted, the estimated braking force can be calculated by the above equation.

Further, the value indicating the driving force obtained by the calculation is, for example,
Fd = T × K / R
It can be expressed as. The meaning of each symbol is as follows.
Fd: Driving force T: (Estimated) Torque K: Total reduction ratio of drive transmission system from engine to driving wheel R: Tire diameter

  The torque T can be obtained by referring to a torque map prepared in advance from the accelerator opening and the engine speed. The torque map is created from engine performance measurement results and the like, and is generally a function such as accelerator opening and engine speed. However, it may be expressed as a function of the intake pressure, and corrections such as loss due to atmospheric pressure, intake air temperature, and gear may be performed.

  The change amount calculation unit 39 obtains a change amount of the rear wheel speed and / or the reference vehicle speed. The change amount calculation unit 39 calculates a difference between the rear wheel speed before 0.1 seconds and the current rear wheel speed, for example. Alternatively, the change amount calculation unit 39 calculates, for example, the difference between the reference vehicle speed 0.1 seconds ago and the current reference vehicle speed.

The learning permission condition determination unit 31 determines whether or not a condition for permitting learning of the tire diameter is satisfied, and notifies the tire diameter correction value calculation unit 32 when the condition is satisfied. The conditions for permitting learning of the tire diameter in the present embodiment are, for example, as follows.
-The braking / driving force is not more than a predetermined value.
The amount of change in wheel speed and / or reference vehicle speed is less than or equal to a predetermined value.
-Wheel speed and / or reference vehicle speed are within a predetermined range.
-Steering angle (steering angle) is within a predetermined range.

  For example, a steering angle sensor may be provided and the steering angle may be determined based on an output signal of the sensor.

  By setting conditions for permitting learning of the tire diameter based on the physical quantities as described above, it is possible to more flexibly determine an appropriate condition for performing the tire diameter. This makes it possible to improve the accuracy of the tire diameter correction value under necessary conditions.

  Note that the change amount calculation unit 39 may perform other processing in addition to the difference calculation. For example, the change amount calculation unit 39 may perform filter processing such as a primary low-pass filter on the calculated difference value. Alternatively, the speed calculation unit 33 may perform filtering on the rear wheel speed and / or the vehicle body speed (front wheel speed), and the change amount calculation unit 39 may calculate the difference using the subsequent signal.

(Embodiment 7: Variations regarding how to obtain tire diameter correction values)
In the present embodiment, a variation in which a tire diameter correction value is calculated using a function of a value representing a wheel speed ratio and a traveling state will be described. The function includes, for example, a braking / driving force function, a wheel speed and / or reference vehicle speed change amount function, a wheel speed and / or reference vehicle speed function, and a posture information value function.

  FIG. 22 is a block diagram showing a configuration of the stability control system 170 according to the present embodiment.

  The configuration of the stable control system 170 is the same as the configuration of the stable control system 160 according to the sixth embodiment except for the following differences. That is, the difference is that the learning permission condition determination unit 31 receives only posture information and determines the learning permission condition, and the type of information received by the tire diameter correction value calculation unit 32 has changed. Specifically, for the latter, the tire diameter correction value calculation unit 32 includes values indicating the braking / driving force output from the braking / driving force control unit 35, posture information output from the posture detection unit 11c, and a change amount calculation unit 39. The information regarding the change amount of the rear wheel speed and / or the reference vehicle speed related to the speed output from the vehicle is received.

  FIG. 23 is a control block diagram of the stability control system 170. The tire diameter correction value calculation unit 32 includes a function calculation unit 32f. FIG. 23 shows only a portion particularly relevant to the present embodiment, and other configurations are illustrated by partially simplifying the configuration of FIG.

  The function calculation unit 32f includes values indicating the braking / driving force output from the braking / driving force control unit 35, posture information output from the posture detection unit 11c, the rear wheel speed related to the speed output from the change amount calculation unit 39, and Information on the amount of change in the reference vehicle speed is received. The function calculation unit 32f holds a predetermined function, and can calculate a tire diameter correction value using them.

An example of the predetermined function is shown below.
(A) Function of front wheel rotational speed / rear wheel rotational speed during traveling and braking force and / or driving force (b) Front wheel rotational speed / rear wheel rotational speed during traveling and rotation of front wheels and / or rear wheels A function of speed (c) a function of the front wheel rotational speed / rear wheel rotational speed during traveling and the amount of change in rotational speed of the front wheels and / or rear wheels (d) front wheel rotational speed / rear wheel rotational speed during traveling A function of the longitudinal acceleration indicated by the acceleration sensor 22

  The function (a) is a combination of conditions to prevent an erroneous correction value from being set due to slip due to braking / driving force, and the tire radius correction value is corrected by using a function of braking / driving force. To do. Since the correction value is set and corrected even in a state where the braking / driving force is acting, the indeterminacy of the correction value due to the influence of the braking / driving force can be suppressed to a small value.

  The function (b) is effective for suppressing the influence of tire inflation. That is, when the tire diameter correction value is set using the difference or ratio between the front wheel rotation speed and the rear wheel rotation speed, the tire expands according to the rotation speed and the like, which affects the tire diameter correction value. Therefore, the tire diameter correction value is corrected using a function related to the rotational speed of the front wheels and / or the rear wheels. As a result, the indeterminacy of the tire diameter correction value due to the influence of tire expansion can be kept small.

  The function (c) corrects the tire diameter correction value by using a function relating to the amount of change in the rotational speed of the front wheels and / or the rear wheels. Since the tire diameter correction value is set and corrected even in the state of acceleration and / or deceleration, the indeterminacy of the tire diameter correction value due to the influence of acceleration / deceleration can be suppressed to be small.

  The function (d) corrects the tire diameter correction value by using a function related to the longitudinal acceleration indicated by the acceleration sensor 22 mounted on the motorcycle 100. Since the tire diameter correction value is set and corrected even in the state of acceleration and / or deceleration, indefiniteness of the correction value due to the influence of acceleration / deceleration can be suppressed to a small value.

  In applying the above-described function, it is possible to set the same traveling condition as described above. That is, the braking force and / or driving force is within a predetermined range, the rotational speed of the front wheels and / or the rear wheels is within a predetermined range, the rotational speed of the front wheels and / or the rear wheels. It is possible to set that the change amount is within a predetermined range and that the longitudinal acceleration is within a predetermined range as the running condition.

  In addition, as a specific example of the functions (a) and (b) described above, the drawings referred to in the description of the eighth embodiment described below can be cited. For example, a specific example of the function (a) is a straight line shown in FIGS. A specific example of the function (b) is a straight line shown in FIGS.

  On the other hand, the present inventors have confirmed that the function (c) can be approximated by a substantially straight line. Since the function (c) approximates the specific example of the function (a), an illustration of a specific example regarding only the function (c) is omitted. As a result of confirmation by the inventors of the present application, when the functions (a) and (c) were compared, it was found that the method of the function (a) had better linearity. Therefore, it is considered that the accuracy of the value approximated by the function (a) is higher.

  Regarding the function (d), the inventors of the present application consider that it tends to be similar to the functions (a) and (c). This is because the longitudinal acceleration is a physical quantity that has a strong correlation with the amount of change in braking force / driving force and wheel speed. Since the function (d) is also approximated to the specific examples of the functions (a) and (c), the specific example relating only to the function (d) is omitted.

  The first to seventh embodiments related to tire diameter correction have been described above. Tire diameter learning may be performed by combining two or more of the tire diameter learning processes of Embodiments 1 to 7 described above. However, since it is not necessary to combine the tire diameter learning according to the fourth embodiment and the tire diameter learning according to the fifth embodiment, any one of them may be adopted alternatively.

(Eighth embodiment: lean correction)
In the eighth embodiment, the lean correction related to the estimation of the apparent slip (lean component) generated by the banking of the vehicle body 1 and the removal of the lean component referred to in FIG. 4 will be described.

  First, the necessity of lean correction will be described in detail.

  Many technologies have been developed to control the braking / driving force of a motorcycle and optimize tire slip. It is known that a certain degree of slip is necessary for the tire to exhibit effective grip performance, and that the maximum grip performance is exhibited at a slip rate of approximately 5 to 20%. An appropriate slip ratio is determined depending on tire performance and road surface conditions.

  It is desirable to set the target value of the optimum slip ratio for exhibiting the grip performance of the tire within this range. The method of obtaining the slip ratio is generally a method of calculating from the rotational speed of each front wheel and rear wheel and the effective diameter (design value) of each tire, but the running tire is different from the fixed effective diameter. Ground by tire diameter. For this reason, the slip calculated during traveling includes, in addition to the actual slip, a component that looks like a slip, that is, an apparent slip, which occurs due to a deviation from the design value of the tire diameter. Deviation from the design value of the tire is caused by, for example, tire replacement, tire wear, expansion, deformation, change in the grounding point due to vehicle body inclination (bank), and the like.

  In order to appropriately intervene the traction control system and the ABS, it is necessary to obtain an accurate slip rate. Apparent slip can be an obstacle in obtaining an accurate slip rate. Therefore, apparent slip must be removed and handled. In the first to seventh embodiments described above, the technology for correcting the shifted tire diameter, which is a factor that causes an apparent slip, is described based on the traveling state when the traveling condition is satisfied.

  A change in the ground contact point due to the inclination (bank) of the vehicle body generates a lean component.

  FIG. 24 shows a contact point A where the tire contacts the ground when the vehicle body is banked. The design value of the tire diameter is given as the length along the alternate long and short dash line from the center axis of the circle to the outermost peripheral point B when the unused tire is viewed as a circle. On the other hand, the running tire diameter is given as the length of the line segment parallel to the alternate long and short dash line from the center axis of the circle to the contact point A. The deviation P corresponds to a deviation from the design value of the tire diameter. The deviation amount P is a factor that gives an incorrect vehicle body speed, front wheel rotational speed, and / or rear wheel rotational speed, and affects the calculation of the slip ratio as an apparent slip, that is, a lean component.

  The effective diameter of a running tire changes from moment to moment, and because the tires are constantly subjected to braking and driving forces to cause appropriate slipping, it is actually difficult to separate the apparent slip. is there. Therefore, a method for setting and evaluating the target slip as an amount including the apparent slip is required.

  However, it is difficult to compare the set target value with the theoretical slip necessary to exhibit grip performance. For this reason, it becomes impossible to theoretically verify whether or not the developed tire slip control device is designed to effectively exert the grip performance of the tire.

  Therefore, in developing an optimal tire slip control device, it is necessary to determine how much apparent slip is included from the measured slip data in order to design the tire grip performance effectively. is there.

  As described above, in the embodiments described so far, the technology for correcting the tire diameter shifted during actual traveling and reducing the influence of the apparent slip has been described. In the following embodiment, a technique for a manufacturer of the motorcycle 100 to estimate a lean component generated due to the bank of the vehicle body of the motorcycle 100 will be described. By estimating the lean component, the manufacturer can operate the traction control system of the motorcycle 100 and a stable control system such as ABS as appropriately as possible regardless of the driving conditions.

  As a technique for estimating the lean component, a technique for obtaining the lean component from the profile shape (lateral radius) of the tire has been devised (for example, Patent Document 2). It has been found that the profile shape differs between a dynamic value (shape during travel) and a static value (shape during stop). Even if the lean component is corrected with a static value, the actual data may still include an apparent slip or an excessive correction may be performed. Therefore, the profile shape is more preferably obtained by measuring a dynamic value from actual travel data.

  However, the measurement data during traveling includes apparent slips and actual slips other than the lean component even in a traveling state that can be controlled by the rider. Therefore, it is difficult to measure a dynamic profile shape.

  FIG. 25 shows slips (a) to (e) that may be included during travel.

  The slip (a) is an apparent slip due to the influence of the deformation of the tire due to the centrifugal force of the tire rotation. As described in the second embodiment, the tire can be inflated by the centrifugal force of the wheel rotation. In addition, in this Embodiment, although the apparent slip by expansion | swelling of a tire is illustrated, it is not restricted to this.

  Slip (b) is an apparent slip resulting from the effect of the pure tire shape. The pure tire shape is a static (fixed) value represented by a tire cross-sectional shape (tire profile).

  The slip (c) is an apparent slip generated due to various factors other than the tire static shape. This is an apparent slip caused by dynamic factors such as tire crushing and deformation accompanying load movement. This tire deformation is a dynamic value unlike the tire profile.

  The slip (d) is a slip that the rider can tolerate and is required to exert a grip. Note that the allowable value of the slip amount can be changed by the rider. For example, when the operation mode related to the traction control and the ABS control of the motorcycle 100 can be switched to a plurality of stages, the allowable value of the slip amount can be changed according to each operation mode.

  Slip (e) is a slip that the rider cannot tolerate. This slip means that the tire slips out of grip. A stable control system can be utilized to prevent the occurrence of slip (e). Obviously, the stable control system cannot be properly intervened without properly recognizing the slips allowed and not allowed by the rider.

  The above-mentioned slips (a), (b) and (c) are classified as apparent slips and are not actually generated slips. When determining the slip ratio, it is necessary to remove these slips (a), (b) and (c).

  The slip (a) can be removed by a known method or, for example, the method of the second embodiment described above.

  On the other hand, slips (b) and (c) are apparent slips generated by banks of the vehicle body, that is, lean components. In Patent Document 2 described above, the slip (b) is merely obtained, and the slip (c) is not obtained.

  FIG. 26 is a plot of data obtained by measuring the cross-sectional shape of a tire in a stationary state. Each point represents a measurement point. A curve connecting the points indicates a line obtained by complementing the cross-sectional shape as a circular shape. The inner curve shows the stationary cross-sectional shape of the front tire, and the outer curve shows the stationary sectional shape of the rear tire.

  FIG. 27 shows the difference between the static cross-sectional shape and the dynamic cross-sectional shape measured by the present inventors. The solid line indicates the ratio of the change rate of the effective diameter of the front and rear tires obtained from the running data. A broken line shows the ratio of the change rates of the effective diameters of the front and rear tires acquired from the cross-sectional shape measured in a stationary state.

  Since the solid line and the broken line do not coincide with each other, it is considered that in addition to the static cross-sectional shape, a factor that affects the ratio of the change rate of the effective diameter of the front and rear tires is added during traveling. For example, tire deformation may be considered as the factor. Therefore, the inventors of the present application have come to the conclusion that it is appropriate to extract the lean component from the running data, not the value in the tire drawing showing only the static cross-sectional shape.

  Therefore, in the present embodiment, a method for obtaining a dynamic value of a profile shape by separating and extracting only an apparent slip due to a lean component from actual traveling data will be described.

  First, the configuration of the motorcycle 100 relating to the present embodiment will be described. The lean correction according to the present embodiment is a process performed by the manufacturer of the motorcycle 100 at the development stage. The motorcycle 100 shown in FIG. 2 has been described as a completed product after the end of development. However, in the embodiment relating to the lean correction, for convenience of explanation, the motorcycle 100 will be described as being a test vehicle at the development stage.

  FIG. 28 is a block diagram showing a configuration of a measurement data acquisition system 180 of the motorcycle 100 according to the present embodiment. The configuration of the measurement data acquisition system 180 is similar to the configuration of the stability control system 110 described in FIG. Constituent elements having the same function are denoted by the same reference numerals and description thereof is omitted.

  The measurement data acquisition system 180 does not include a configuration for stable control in the stability control system 110, such as the control wheel speed calculation unit 34 and the braking / driving force control unit 35. On the other hand, the storage device 40 of the measurement data acquisition system 180 stores measurement data 55 that is a measurement result and is used for the development of the motorcycle 100.

  FIG. 29 shows a procedure for lean correction according to the present embodiment.

  First, in step S51, the motorcycle 100 travels without applying a driving force with the rider holding the vehicle body 1 upright. “Without driving force” means to slide with the clutch off. The relationship between the reference vehicle speed during sliding and the wheel speeds of the front and rear wheels is acquired. When the reference vehicle speed is the wheel speed of the front wheel, the wheel speed of the rear wheel may be acquired. As described in the second embodiment, the relationship between the reference vehicle body speed and the wheel rotation speed acquired at this time includes the influence of wheel expansion.

  Next, in step S52, the motorcycle 100 travels by applying a driving force in a state where the rider keeps the vehicle body 1 upright. However, sudden acceleration / deceleration is not performed. At this time, the tire diameter correction value calculation unit 32 performs tire diameter correction in advance in order to eliminate the influence of the expansion obtained in step S51. The relationship between the driving force and the front and rear wheels is then observed. As a result, the relationship between the driving force and the front and rear wheels when a slip allowable for the rider is generated can be acquired.

  In step S53, the motorcycle 100 is caused to travel including the state in which the rider tilts the vehicle body 1. However, sudden acceleration / deceleration is not performed in this case. At this time, the tire diameter correction value calculation unit 32 performs tire diameter correction in advance in order to eliminate the influence of the expansion obtained in step S51. Further, the tire diameter correction value calculation unit 32 performs tire diameter correction related to the influence of the driving force obtained in step S52. Then, look at the relationship between the bank angle and the front and rear wheels. Thereby, the influence when the vehicle body 1 is banking, that is, the influence of the lean component can be obtained.

  Each of the above-described steps S51 to S53 will be described in detail below.

  FIG. 30 shows the slip component separation related to step S51 of FIG. The traveling condition is that the motorcycle 100 travels without applying a driving force in a state where the rider keeps the vehicle body 1 upright. Lean components (b) and (c) are not generated by raising the vehicle body 1 upright. Furthermore, since no driving force is applied, slip (d) for exerting a grip does not occur. Of course, no slip (e) occurs. Therefore, the relationship between the reference vehicle speed and the wheel speed acquired in step S51 includes only the influence of slip (a), that is, the expansion characteristic.

  FIG. 31 shows measurement data relating to expansion characteristics. The vertical axis represents the front-rear wheel speed ratio, and the horizontal axis represents the front wheel speed. FIG. 32 shows a graph in which the measurement data of FIG. 31 is further simplified. For ease of understanding, the scales of the vertical and horizontal axes of the data shown in FIG. 32 are changed from those shown in FIG. In any of the drawings, the vertical axis represents the rear wheel speed / reference vehicle speed, and the horizontal axis represents the reference vehicle speed. Each point represents data measured by each trial. A straight line indicates an approximate line that best represents each point.

  The front-rear wheel speed ratio is not constant, but varies depending on the vehicle speed. This is considered due to the tire expanding. By knowing in advance the relationship between the wheel speed of the rear wheel / reference vehicle speed according to the reference vehicle speed, the influence of tire expansion can be eliminated by correction. Specifically, it is as described in the second embodiment. Specifically, the tire diameter can be corrected using the tire expansion correction value by the same method as in step S35 of FIG. This processing is performed by the arithmetic unit 30.

  FIG. 33 shows the separation of slip components related to step S52 of FIG. The traveling condition is that the motorcycle 100 travels with a driving force applied with the rider holding the vehicle body 1 upright. First, the slip component (a) obtained in step S51 is corrected and does not exist. And lean components (b) and (c) are not generated by raising the vehicle body 1 upright. On the other hand, since a driving force is applied, it can be said that only slip (d) for exerting a grip is generated.

  FIG. 34 shows measurement data relating to running characteristics during running with driving force applied. The vertical axis represents the front-rear wheel speed ratio after performing the expansion correction, and the horizontal axis represents the magnitude of the rear wheel driving force. Each point represents data measured by each trial. A straight line indicates an approximate line that best represents each point. FIG. 35 shows a simplified graph of the measurement data of FIG. For easy understanding, the scales of the vertical axis and the horizontal axis of the data shown in FIG. 35 are changed from those scales shown in FIG.

  By applying the driving force, the relationship between the wheel rotational speeds of the front and rear wheels changes. That is, slip occurs. This slip is considered to be a slip necessary for exerting a grip. By grasping in advance the relationship of how much potential slip occurs depending on the magnitude of the driving force, the influence of the slip generated by applying the driving force can be eliminated by correction.

  Note that, when the motorcycle 100 includes a plurality of operation modes having different slip amount tolerances, the relationship between the wheel rotational speeds of the front and rear wheels may be acquired for each of the plurality of operation modes. For example, when the motorcycle 100 is developed as a model capable of running on both a circuit and an urban area, the operation mode includes a racing mode for racing in fine weather, a rainy mode for racing in rainy weather, and an urban area for urban areas. It is possible to set the mode. A different allowable slip amount can be set for each of the racing mode, the rainy weather mode, and the urban area mode. Also, different slip amount tolerances can be set according to the strength of traction control and ABS intervention. In order to determine such an allowable value, it is useful to obtain the relationship between the wheel rotational speeds of the front and rear wheels when different driving forces are applied to each of the plurality of travel modes.

  FIG. 36 shows the separation of slip components related to step S53 of FIG. The traveling condition is that the motorcycle 100 travels including a state where the rider tilts the vehicle body 1. As described above, the slip component (a) does not exist due to the correction. Further, regarding the slip component (d), the influence of the wheel speed / reference vehicle body speed specified according to the rear wheel driving force may be eliminated. Thereby, only the slip generated by the bank of the vehicle body 1 during traveling, that is, the lean component can be specified.

  FIG. 37 shows measurement data relating to travel characteristics during travel including a state in which the vehicle body 1 is tilted. The vertical axis shows the value of (front-rear wheel speed ratio-1) after correcting the slip when the driving force is applied, and the horizontal axis shows the bank angle. Each point represents data measured by each trial. The curve shows an approximate line that best represents each point. FIG. 38 shows a simplified graph of the measurement data of FIG. In FIG. 38, the vertical axis is expressed as “ratio of the change rate of the effective diameter of the front and rear wheels due to the vehicle body inclination”, but this expression is substantially the same as the vertical axis in FIG.

  For example, as shown in FIG. 38, it can be seen that the tire effective diameter is changed by running the vehicle 1 in a bank. This relationship is considered to reflect only the influence of the bank of the vehicle body 1. That is, this data can be used for lean correction. This is because the change in the tire effective diameter of the front and rear wheels according to the bank angle affects the front and rear wheel speeds.

  An additional description will be made regarding the slip component (d) in FIG.

  The inventors of the present application have the value K of the front / rear wheel speed ratio after the expansion / driving force correction remains the value K1 corresponding to the dynamic profile shape during traveling of the motorcycle 100 and the driving force correction. It was confirmed that it was represented by the sum with the value K2. The value K1 is a value that can be used for lean correction. The value K2 is a function of the driving force F. In order to obtain the value K1 from the value K of the front / rear wheel speed ratio after the expansion / driving force correction obtained by measurement, the value K2 needs to be set to 0 as much as possible. That is, it is necessary to bring the driving force close to zero.

  39 (a) and 39 (b) show the results of measuring the change rate of the effective diameter of the front and rear wheels. Until now, the front wheel speed was the reference vehicle speed. In this example, the reference vehicle speed is acquired using GPS. And the change rate of the effective diameter was measured about each of the front wheel and the rear wheel according to the bank angle. In place of the front wheel speed, the accuracy is improved by calculating the reference vehicle speed by GPS or the like and calculating the change rate of the effective diameters of the front and rear. Therefore, when the ratio of the change rate of the effective diameter for the front and rear wheels is obtained from these measurement data, a more accurate ratio of the change ratio of the effective diameter is obtained than the graph of FIG. It is thought that.

  Now, in order to calculate the rate of change of the effective diameters of the front and rear, the method of obtaining the reference vehicle speed by GPS or the like is method (A), and the method of obtaining the front wheel speed as the reference vehicle speed is method (B) write. The method (A) can acquire more information on the vehicle body speed by GPS than the method (B). Further, the relationship between the vehicle body speed by GPS and the front wheel speed and the relationship between the GPS vehicle body speed and the rear wheel speed can be obtained independently. Therefore, the rate of change of the effective diameter of each of the front and rear wheels ((a) and (b) in FIG. 39) can be obtained independently. With the method (B), the amount of information regarding the vehicle body speed by GPS is inferior, and the rate of change in the effective diameter of the front and rear wheels cannot be obtained independently. Therefore, it can be said that the method (A) is more preferable in terms of accuracy than the method (B).

  The above-described value K2 is a value that remains even if the driving force is corrected. Therefore, in order to calculate the value K2, information on the change rate of the effective diameter of the rear wheel that is the drive wheel ((b) in FIG. 39) is required. At this time, as described above, the driving force F needs to be close to 0 in the method (B), but it is not necessary to approach F to 0 in the method (A). From this point of view, it can be said that the method (A) is more accurate than the method (B).

  Information representing the ratio of the change rate of the effective diameter of the front and rear tires according to the bank angle is used as a numerical table for lean correction. This numerical table is used for the lean component estimation process in step S3 of FIG. Specifically, when the bank angle information is acquired while the motorcycle 100 is traveling, the ratio of the change rates of the effective diameters of the front and rear tires corresponding to the bank angle can be specified with reference to this numerical table. By correcting the slip ratio on the premise of the ratio, it becomes possible to intervene with a traction control system and a stable control system such as ABS more accurately. This slip ratio correction is called lean correction.

  In the calculation formula for the lean component, the apparent slip ratio is expressed as Pf / Pr-1. The value of Pf / Pr-1 corresponds to the vertical axis of FIGS. The apparent slip amount is expressed as (Pf / Pr-1) · Vf.

  40A to 40C show the results of lean correction of the slip amount in the braking / driving force control. In either case, the horizontal axis is time. The vertical axis is as follows. The solid line in (a) is the rear wheel speed, and the broken line is the front wheel speed. (B) shows the bank angle of the vehicle body. The solid line in (c) indicates the slip amount before correction, and the short broken line indicates the lean component. Further, the long broken line indicates the corrected slip amount.

(Embodiment 9: Tire diameter learning + lean correction)
As shown in FIG. 4, the tire diameter correction process described in the first to seventh embodiments and the lean correction process described in the eighth embodiment can be performed in the same motorcycle 100.

  For example, the stable control system 110 according to the first embodiment shown in FIG. 7 will be described as an example. Information indicating the ratio of the change rate of the effective diameter of the front and rear tires according to the bank angle for lean correction is stored in the storage device 40. After the braking / driving force control unit 35 calculates the slip ratio, the information may be read from the storage device 40 and the lean correction may be executed. It is sufficient if the braking / driving force control unit 35 adds a signal line that can refer to the storage contents of the storage device 40. The same applies to stable control systems according to other embodiments.

  The embodiment of the present invention has been described above.

  In the description of the above-described embodiment, the processing example using the bank angle as the physical quantity indicating the inclination of the vehicle body has been described. However, the bank angle as a physical quantity indicating the inclination of the vehicle body is an example. For example, a yaw angular velocity or a lateral acceleration can also be used. From the characteristics of the motorcycle, it is considered that the vehicle is in an inclined state if the vehicle body is inclined. This means that a yaw angular velocity component is generated. Therefore, it can be said that the yaw angular velocity is a physical quantity indicating the inclination of the vehicle body. Alternatively, it is considered that the gravity component can be detected as a lateral acceleration if the vehicle body is in a tilted state, or a lateral acceleration is generated if the vehicle body is in a turning state. Therefore, the lateral acceleration can also be referred to as a physical quantity indicating the inclination of the vehicle body. Note that the yaw angular velocity and the lateral acceleration are physical quantities obtained directly from the sensor value, and there is an advantage that the calculation for calculating the bank angle can be omitted. Further, since it is possible to determine at least whether or not the vehicle body is in an upright state, it is more suitable for the processing of the fifth embodiment, for example.

  In addition, as a timing for learning the tire diameter correction value, one of a condition that the vehicle body speed is within a predetermined range and a condition that the braking force and the driving force applied to the vehicle are equal to or less than a predetermined value are You may go when you are satisfied.

  The processes described in connection with the above embodiments can be realized as software (computer program) executed by a computer. For example, each block shown in FIGS. 5 and 6 can be realized as a sub-routine of a computer program. Further, the flowchart of FIG. 9 and the like can be realized as a main routine of a computer program including such a sub-routine. Such a computer program is stored in the storage device 40, read out from the storage device 40 in response to power-on of the motorcycle 100, and expanded in a RAM (not shown). And it is sequentially executed by the arithmetic unit (CPU) 30 of the ECU 10. Further, such a computer program can be recorded on a recording medium such as a CD-ROM and distributed as a product to the market, or can be transmitted through an electric communication line such as the Internet.

  The present invention can be used as a stable control system for a saddle-ride type vehicle. The present invention can also be used as a saddle-ride type vehicle in which such a stable control system is mounted.

1 body 2 front wheel 3 rear wheel 10 controller (ECU) 10
11a Reference vehicle speed sensor 11b Wheel rotation speed sensor 11c Attitude detection unit 12 Throttle 13 Spark plug 21 Angular speed sensor 22 Acceleration sensor 23 Attitude calculation unit 30 Calculator (CPU)
31 learning permission condition determination unit 32 tire diameter correction value calculation unit 33 speed calculation unit 34 control wheel speed calculation unit 35 braking / driving force control unit 40 storage device 50 braking / driving force adjustment unit 110, 120, 130, 160, 170 stability control System 180 Measurement system

Claims (10)

A measurement data acquisition system for acquiring measurement data using a test vehicle having a first wheel and a second wheel,
A wheel rotation speed sensor for acquiring a first wheel rotation speed and a second wheel rotation speed, which are rotation speeds of the first wheel and the second wheel, respectively;
First measurement data indicating the relationship between the first wheel rotation speed and the second wheel rotation speed obtained during traveling without applying the driving force and the braking force is set to at least the first wheel rotation speed. And an arithmetic unit that obtains it according to
The first wheel and the second wheel are deformed due to rotation according to a vehicle body speed of the test vehicle, and when the first wheel rotation speed is regarded as the vehicle body speed, The relationship between the first wheel rotation speed and the second wheel rotation speed indicated by the measurement data is an expansion characteristic related to the deformation of the first wheel and the second wheel due to the rotation according to the vehicle body speed. Is obtained as
The first measurement data is mounted on a predetermined vehicle, so that when the first wheel rotation speed of the predetermined vehicle is given, the first wheel rotation speed and the second wheel rotation speed of the predetermined vehicle. Measurement data acquisition system used to determine the relationship between The computing unit is
Correcting the second wheel rotation speed by using the first measurement data as a tire diameter correction value at the first wheel rotation speed;
During the traveling with the driving force applied to the second wheel, second measurement data indicating the relationship between the first wheel rotation speed and the corrected second wheel rotation speed is determined according to the driving force. Acquired,
The second measurement data is mounted on the predetermined vehicle, so that when the driving force is applied to the driving wheel of the predetermined vehicle, the first wheel rotation of the predetermined vehicle according to the driving force is performed. The measurement data acquisition system according to claim 1, wherein the measurement data acquisition system is used to obtain a relationship between a speed and a second wheel rotation speed. The relationship between the first wheel rotation speed and the second wheel rotation speed indicated by the first measurement data is a ratio between the first wheel rotation speed and the second wheel rotation speed at the first wheel rotation speed. And
The measurement data acquisition system according to claim 2, wherein the computing unit obtains the corrected second wheel rotation speed by multiplying the first measurement data and the first wheel rotation speed. A posture detection unit for obtaining a bank angle of the vehicle body of the test vehicle;
The measurement data acquisition system according to claim 2, wherein the computing unit acquires the second measurement data when the predetermined bank angle is substantially 0 °. The computing unit is
Using the second measurement data as a tire diameter correction value in the driving force to further correct the corrected second wheel rotation speed,
During traveling with the vehicle body of the test vehicle banked at a predetermined bank angle, third measurement data indicating a relationship between the first wheel rotation speed and the corrected second wheel rotation speed is set to the bank angle. Get according to
The third measurement data is mounted on the predetermined vehicle, so that when the vehicle body of the predetermined vehicle is banked, the first wheel rotation speed and the second wheel of the predetermined vehicle according to the bank angle. The measurement data acquisition system according to claim 4, which is used for obtaining a relationship between rotational speeds. The relationship between the first wheel rotation speed and the corrected second wheel rotation speed indicated by the second measurement data is as follows: the first wheel rotation speed and the corrected second wheel rotation speed in the driving force. And the ratio
The measurement data acquisition system according to claim 5, wherein the arithmetic unit obtains the corrected second wheel rotation speed by multiplying the second measurement data and the first wheel rotation speed. The relationship between the first wheel rotation speed and the corrected second wheel rotation speed indicated by the third measurement data is the first wheel rotation speed corresponding to the bank angle and the corrected second wheel. Is the ratio to the rotational speed,
The measurement data acquisition system according to claim 6, wherein the arithmetic unit obtains the corrected second wheel rotation speed by multiplying the third measurement data and the first wheel rotation speed. A brake that generates braking force;
A motor that generates driving force;
A measurement data acquisition system according to any one of claims 1 to 7,
A vehicle further comprising a storage device for storing the acquired data. A method of acquiring measurement data using a test vehicle having a first wheel, a second wheel, a wheel rotation speed sensor, and a calculator,
Using the wheel rotation speed sensor, obtain the first wheel rotation speed and the second wheel rotation speed, which are the rotation speeds of the first wheel and the second wheel, respectively.
Measurement data indicating a relationship between the first wheel rotation speed and the second wheel rotation speed obtained during traveling without applying the driving force and the braking force using the arithmetic unit, Measurement data used for obtaining the relationship between the first wheel rotation speed and the second wheel rotation speed of the vehicle when the first wheel rotation speed of the predetermined vehicle is given by being mounted on the vehicle. According to at least the first wheel rotation speed,
The first wheel and the second wheel are deformed due to rotation according to a vehicle body speed of the test vehicle, and when the first wheel rotation speed is regarded as the vehicle body speed, The relationship between the first wheel rotation speed and the second wheel rotation speed indicated by the measurement data is an expansion characteristic related to the deformation of the first wheel and the second wheel due to the rotation according to the vehicle body speed. Get as the way A computer program executed by the computing unit to obtain measurement data using a test vehicle having a first wheel, a second wheel, a wheel rotation speed sensor, and a computing unit,
The computer program is stored in the calculator.
A process of receiving a first wheel rotation speed and a second wheel rotation speed, which are rotation speeds of the first wheel and the second wheel, acquired using the wheel rotation speed sensor;
Measurement data indicating the relationship between the first wheel rotation speed and the second wheel rotation speed obtained during traveling without applying the driving force and the braking force, and mounted on a predetermined vehicle When the first wheel rotation speed of the predetermined vehicle is given, at least the first wheel is used as measurement data used to obtain the relationship between the first wheel rotation speed and the second wheel rotation speed of the vehicle. The processing to be acquired according to the rotation speed and
The first wheel and the second wheel are deformed due to rotation according to a vehicle body speed of the test vehicle, and when the first wheel rotation speed is regarded as the vehicle body speed, The relationship between the first wheel rotation speed and the second wheel rotation speed indicated by the measurement data is an expansion characteristic related to the deformation of the first wheel and the second wheel due to the rotation according to the vehicle body speed. Ru is obtained as, a computer program.

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