JP5691757B2 - Step climbing detection device - Google Patents

Description

  The present invention relates to a step climbing detection device that detects that a vehicle has climbed a step.

  There are cases where the vehicle needs to climb over or over a step, or may unintentionally climb over the step. In such a case, the vehicle receives resistance once, so the driver depresses the accelerator pedal slightly. When the level difference is small, the torque increases as the engine speed increases and the level difference can be overcome.

  However, if the level difference is large, depressing the accelerator pedal further increases the torque and rides on the level difference. At this time, the resistance due to the level difference decreases at a stroke, so the behavior of the vehicle changes suddenly, and the driver may feel uneasy. In addition, when the step provided on the car stop is in the immediate vicinity, the driver may perform a series of operations without being aware of the step being blocked by the vehicle body. Will be invited. In order to solve such a problem, a technique for estimating step climbing from the relationship between generated torque and vehicle speed is known (Patent Document 1). In particular, this tendency becomes prominent in vehicles having an automatic transmission that does not use a torque converter, which has been increasing in recent years. For such vehicles as well, climbing a step from the relationship between the generated torque and the vehicle speed. There is also a technique that discloses a technique for estimating (Patent Document 2).

  On the other hand, a technique for detecting the air pressure of a tire of a vehicle is known. For example, in order to prevent accidents during high-speed driving due to a decrease in tire pressure, it is mandatory to install a tire pressure monitoring system (TPMS (registered trademark)) that constantly monitors tire pressure and warns of a decrease. Some countries are spreading and are becoming more widespread.

  There are a direct type (Patent Document 3) and an indirect type (Patent Document 4) in TPMS. The direct type measures the pressure in the tire with a pressure sensor, wirelessly transmits the measured data from a transmitter installed in the tire, receives it with a receiver installed in the vehicle body, and receives the tire with an ECU (Electronic Control Unit) When it is determined that the air pressure is out of the standard, a warning is displayed. The indirect type mainly sends data via a wired transmission line, and the ECU estimates a decrease in tire air pressure from the dynamic load radius or resonance frequency, etc., and displays a warning if it is determined that it is out of the standard. is there.

JP 2007-30581 A JP 2007-45230 A JP 2010-112818 A JP 2005-193712 A

  When estimating the step climbing from the relationship between the generated torque and the vehicle speed, inconvenience can be considered. For example, assuming a road where the uphill steep slope and the flat part are continuous, it is possible to be mistakenly recognized as stepping and braking when approaching the flat part immediately after starting the slope near the end of the steep slope There is sex. In particular, this is influenced by the number of passengers and the load. Such control that is not intended by the driver or control that is not suitable for the situation is not desirable in view of the relationship with the following vehicle.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a step climbing detection device that can accurately detect the step climbing of a vehicle.

The invention according to claim 1, which has been made to achieve the above object, is a step climbing detection device for detecting that a vehicle has climbed a step, and a pressure detection means for detecting tire pressure provided on a wheel, And a ride determination unit that determines whether or not the vehicle has climbed a step based on a detection signal from the pressure detection unit, and is configured to receive a wheel speed signal indicating a wheel rotation speed. When the value obtained by dividing the time integral value of the detection signal by the detection means by the wheel rotation speed is greater than a predetermined threshold value, it is determined that the vehicle has climbed the step .

  According to this configuration, in the process in which the wheel climbs up the step, the tire air pressure changes different from normal. At this time, the pressure detection means detects a change in the tire air pressure, and the climbing determination means determines that the tire has climbed the step based on the detection signal from the pressure detection means. Therefore, the step climbing is detected based on the change in the tire air pressure of the wheel that is in direct contact with the step, so that it is possible to accurately detect the step climbing.

Also , when the wheel tries to climb a step with a certain speed, the tire air pressure increases. At this time, the pressure detection means detects an increase in tire air pressure, and the ride-up determination means determines the difference in level when the value obtained by dividing the time integral value of the detection signal by the pressure detection means by the wheel rotational speed is greater than a predetermined threshold value. It is determined that you have boarded. Therefore, since the time integral value is divided by the wheel rotation speed out of the change in the tire air pressure of the wheel that is in direct contact with the step, the influence on the detected tire air pressure due to the speed can be reduced, so the judgment is based only on the size of the step. It is possible to produce an effect that it is possible to accurately detect the climbing of the step regardless of the vehicle speed.

The invention according to claim 2 is characterized in that the riding means compares a value based on the tire air pressure detection signal with a predetermined depression detection threshold value and determines whether or not the depression has fallen into the depression. And

  According to this configuration, when the wheel falls into the depressed portion, the tire air pressure changes so as to increase significantly. At this time, the pressure detection means detects an increase in tire air pressure, and the ride determination means compares the value based on the tire air pressure detection signal with a predetermined depression detection threshold value to determine whether the tire has fallen into the depression. Determine. Therefore, since it detects based on the tire air pressure of the wheel which contacts a depression part directly, there exists an effect that a depression part can be detected correctly.

The invention according to claim 3 is characterized in that the pressure detecting means is provided on at least a front wheel of a vehicle, and the climbing judgment means performs judgment of whether or not the vehicle has climbed the step for each wheel. .

  According to this configuration, when at least the front wheels try to ride on the step, or when the front wheel falls on the step, the tire air pressure changes so as to increase. At this time, the pressure detecting means detects an increase in the tire air pressure, and the riding-up determining means determines for each wheel that the tire has climbed or dropped into the step. Therefore, since the step is detected by a change in tire air pressure at least for each front wheel that directly contacts the step or depression, the step or depression on the outside of the wheel base when moving forward, or inside the wheel base when moving backward It is possible to detect that the vehicle has stepped on a certain level difference or has fallen into a depression, and at that time, when only one of the front wheels rides on the level difference or falls into the depression, it can be accurately detected. There is an effect that it can be detected.

According to a fourth aspect of the present invention, there is provided a transmitting means for wirelessly transmitting a tire air pressure detection signal by the pressure detecting means, and a receiving means for receiving the tire air pressure detection signal wirelessly transmitted by the transmitting means. The climbing determination means determines whether or not the rider has climbed a level difference or has fallen into a depression based on the tire air pressure detection signal received by the receiving means.

  According to this configuration, the transmission means wirelessly transmits the detection signal detected by the pressure detection means, the reception means receives the detection signal, and the climbing determination means is based on the tire air pressure detection signal received by the reception means. It is determined whether or not the vehicle has stepped on a step or whether or not it has fallen into a depression. Therefore, since the pressure detecting means can be installed at a place where the tire pressure can be directly measured, it is possible to make a determination based on a signal obtained by directly measuring the tire pressure, and there is an effect that an accurate determination can be made.

The invention described in claim 5 is characterized in that the pressure detecting means, the transmitting means and the receiving means are shared with a tire pressure monitoring system. According to this structure, there exists an effect that the said apparatus can be comprised cheaply by utilizing the existing components in the vehicle provided with the tire pressure monitoring system.

The invention described in claim 6 is characterized in that the pressure detecting means and the transmitting means are provided in an air chamber of the tire. According to this configuration, there is an effect that the tire pressure can be accurately detected without changing the configuration of the wheels, and the ride on the step can be accurately detected.

The invention according to claim 7 is characterized in that the pressure detecting means and the transmitting means are provided on the inner peripheral side of the rim portion of the wheel. According to this configuration, there is an effect that the battery can be easily replaced.

It is a block diagram which shows schematic structure of the vehicle carrying the level | step difference boarding detection apparatus which concerns on a 1st reference example . (A) is a schematic diagram which shows a mode that the tire contacted the level | step difference, (b) is a schematic diagram which shows a mode that the tire got on the level | step difference. It is a graph which shows the outline of the change of the tire air pressure at the time of riding on the level | step difference which concerns on a 1st reference example . It is a flowchart which shows the process in the level | step difference climb detection apparatus which concerns on a 1st reference example . It is a graph which shows the outline of the change of the tire air pressure through the high pass filter which concerns on a 2nd reference example . It is a flowchart which shows the process in the level | step difference climb detection apparatus which concerns on a 2nd reference example . It is a graph which shows the outline of the change of the pressure change rate which concerns on a 3rd reference example . It is a flowchart which shows the process in the level | step difference climb detection apparatus which concerns on a 3rd reference example . It is a graph which shows the outline of the difference by the speed of the tire pressure change at the time of stepping over a level | step difference. It is a flowchart which shows the process in the level | step difference climb detection apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows a mode that the wheel fell into the depression part based on 2nd Embodiment. It is a flowchart which shows the process in the level | step difference boarding detection apparatus which concerns on 2nd Embodiment.

Hereinafter, reference examples and specific embodiments of the step climbing detection apparatus of the present invention will be described with reference to the drawings.
<First Reference Example >
First, a step climb detection device 10 according to a first reference example of the present invention will be described with reference to FIGS. As shown in FIG. 1, a step climb detection device 10 according to this reference example is mounted on a vehicle, and is provided on a wheel provided with a tire 6 to detect a tire air pressure, and a transmission. It consists of a machine 2, a receiver 3, and an ECU 5. Further, the vehicle is provided with a wheel speed sensor 4 that outputs a wheel speed signal indicating a wheel rotation speed, and the wheel speed signal is input to the ECU 5 via a transmission line.

  The pressure sensor 1 measures the tire air pressure and outputs a detection signal. It has a battery (not shown) (for example, a lithium battery) and is provided in an air chamber that is surrounded by a wheel rim and a tire and filled with air or nitrogen gas.

  Similarly to the pressure sensor 1, the transmitter 2 has a battery (not shown) (for example, a lithium battery) and is provided in the air chamber of the tire 6. The transmitter 2 outputs a tire air pressure detection signal output from the pressure sensor 1 by radio waves. Wireless transmission. The pressure sensor 1 and the transmitter 2 are provided in each tire 6. By transmitting the radio wave, data can be transmitted even when the tire is rotating during traveling. The transmission interval is assumed to be a predetermined interval.

  The receiver 3 is provided, for example, on the ceiling of the passenger compartment, has one or more antennas, receives radio waves sent from the transmitter 2 provided on each wheel, and receives the received measurement values. Is sent to the ECU 5 via a transmission line such as CAN (Controller Area Network).

  The ECU 5 is an electronic control device provided in the passenger compartment, and executes a step-up detection process based on a pressure detection signal or the like input via the receiver 3.

Next, the step climb detection process in the present reference example will be described with reference to FIGS. Assuming that the tire 6 comes into contact with the step and the riding starts, as shown in FIG. 2 (a), the tire 6 comes into contact with the step 7, and the tire is deformed to reduce the volume, so that the tire air rises. To do. If the data is sent at a sufficient frequency at this time, as shown in FIG. 3, an increase in tire air pressure can be observed from the time when the step contact starts. When riding completely as shown in FIG. 2 (b), the tire air pressure decreases rapidly and almost returns to the pressure before riding.

  As shown in FIG. 3, the ECU 5 determines whether or not to ride on the step by comparing the tire air pressure with a predetermined threshold value. The maximum tire pressure when a predetermined torque is generated with respect to the step to be determined is obtained experimentally, and this is used as a threshold value. If the level difference is larger than the level to be determined, the level can be determined before completely climbing.

  This will be described with reference to the flowchart shown in FIG. First, the wheel rotation speed V and the tire pressure P are read (S101). Next, the wheel rotation speed V is compared with the threshold value Vth1 (S102). When the wheel rotation speed V is smaller than the threshold value Vth1, the tire air pressure P is compared with the threshold value Pth1 (S103).

  As described above, the ECU 5 determines whether or not the vehicle has stepped on the level difference only when the vehicle rotation speed is smaller than a predetermined speed (for example, 10 km / h) based on the wheel rotation speed signal. This is because when the vehicle speed is high, the tire air pressure becomes larger than the threshold value even if the level difference is small, and there is a possibility of erroneous detection of climbing on the level difference.

  The above step climbing determination is executed for at least the front wheel and for each wheel. The ECU 5 transmits the determination result to each unit via the CAN. Each unit may warn the driver with, for example, a warning display or a buzzer warning sound, or the ESC-ECU, which is a control unit of the skid prevention mechanism, may operate the brake actuator based on information on the step-up detection device. . At this time, for example, when it is determined that the vehicle has stepped on the step inside the wheelbase when the vehicle is moving backward, the control to distribute the brake pressure to the rear wheels is performed. Just do it.

As is apparent from the above description, according to the present reference example , the pressure sensor 1 (pressure detection means) provided on the wheel for detecting the tire air pressure and the stepped on the step based on the detection signal from the pressure sensor 1 ECU 5 (mounting determination means) for determining whether or not. Therefore, it is possible to accurately detect the ride on the step by detecting the ride on the step based on the change in the tire air pressure of the wheel that directly contacts the step.

Further, according to the present reference example , the ECU 5 (climbing determination means) determines that the vehicle has climbed the step when the detection signal of the pressure sensor 1 is larger than a predetermined threshold value. Therefore, the step climbing is detected based on the change in the tire air pressure of the wheel that is in direct contact with the step, so that it is possible to accurately detect the step climbing for a predetermined step.

Further, according to this reference example , a wheel speed signal indicating the wheel rotation speed is inputted, and when the vehicle speed based on the wheel speed signal is smaller than a predetermined speed, it is determined whether or not the ECU 5 has stepped on the step. Make a decision. According to this configuration, the ECU 5 determines whether to climb a step only when the vehicle speed is equal to or lower than a predetermined speed. Therefore, the ECU 5 can accurately climb a step without erroneously detecting that the vehicle has passed a small undulation. Can be detected.

Further, according to this reference example , the transmitter 2 (transmission means) wirelessly transmits the detection signal detected by the pressure sensor 1, and the receiver 3 (reception means) installed on the vehicle body side receives and inputs it to the ECU 5. Then, the ECU 5 determines whether or not the vehicle has stepped on the level difference based on the tire air pressure detection signal received by the receiver 3. Therefore, since the pressure sensor 1 can be installed in the tire 5 which is a place where the tire air pressure can be directly measured, it is possible to make a ride determination using a signal obtained by directly measuring the tire air pressure, and an accurate determination can be made.
<Second Reference Example >
The second reference example is different from the first reference example only in the method for determining stepping up shown in FIG. In the second reference example , when processing the tire pressure data provided from the pressure sensor 1 to the ECU 5 via the transmitter 2 and the receiver 3, only the high-frequency component is obtained by passing through the high-pass filter, and during the riding process. Ignoring slow changes such as pressure changes, only sudden pressure changes as shown in FIG. 5 can be detected. If a threshold value is provided on the side where the tire air pressure decreases as shown in FIG. 5, it is possible to determine whether or not the step has been climbed with a rapid decrease in the tire air pressure when the tire is completely ridden. The threshold and high-pass filter characteristics are determined experimentally. As in the first reference example , it is appropriately combined with the information of the wheel speed sensor 4 so that it is not determined that the step climbing is detected at a predetermined speed or higher.

  Hereinafter, description will be given according to the flowchart shown in FIG. First, the wheel rotation speed V and the high-frequency component Phf of tire pressure are read (S201). Next, the wheel rotation speed V is compared with the threshold value Vth2 (S202). When the wheel rotation speed V is smaller than the threshold value Vth2, the high-frequency component Phf of the tire air pressure is compared with the threshold value Pth2 (S203).

As is apparent from the above description, according to the present reference example , the pressure sensor 1 (pressure detection means) provided on the wheel for detecting the tire air pressure and the stepped on the step based on the detection signal from the pressure sensor 1 ECU 5 (climbing determination means) for determining whether or not the vehicle has traveled, and ECU 5 determines whether or not the vehicle has climbed a step based on the high-frequency component of the signal. Accordingly, since the change is detected only by a sudden and large change on the tire air pressure of the wheel that is in direct contact with the step, it is possible to accurately detect the ride on the step.

Further, according to this reference example , the transmitter 2 (transmission means) wirelessly transmits the detection signal detected by the pressure sensor 1, and the receiver 3 (reception means) installed on the vehicle body side receives and inputs it to the ECU 5. Then, the ECU 5 determines whether or not the vehicle has stepped on the level difference based on the high frequency component of the tire air pressure detection signal received by the receiver 3. Therefore, since the pressure sensor 1 can be installed in the tire 5 which is a place where the tire air pressure can be directly measured, it is possible to make a ride determination using a signal obtained by directly measuring the tire air pressure, and an accurate determination can be made.
<Third reference example >
The third reference example is different only in the method for determining stepping up shown in FIG. 3 in the first reference example . In the first reference example , the tire air pressure is simply compared with the threshold value. Here, as shown in FIGS. 7 and 8, the maximum value of the change rate of the tire air pressure is not more than the predetermined threshold value. In this case, it is determined that the step is climbing. By doing so, it is possible to prevent a sudden change in pressure due to undulations of stones or the like during traveling from being determined as stepping on a step. Similar to the first reference example and the like, together with the information of the wheel speed sensor 4, it is determined not to detect step climbing detection at a predetermined speed or higher.

  Hereinafter, description will be given according to the flowchart shown in FIG. First, the wheel rotation speed V, the tire pressure P, and the maximum value (ΔP / Δt) max of the change rate of the tire pressure are read (S301). Next, the wheel rotation speed V is compared with the threshold value Vth3 (S202). When the wheel rotation speed V is smaller than the threshold value Vth3, the tire air pressure P is compared with the threshold value Pth3 (S303). When the tire pressure P is greater than the threshold value Pth3, the maximum value (ΔP / Δt) max of the change rate of the tire pressure is further compared with the threshold value Rth. The maximum value (ΔP / Δt) max of the tire air pressure change rate is determined for a predetermined time by a predetermined routine.

As is apparent from the above description, according to this reference example , the pressure sensor 1 (pressure detection means) provided on the wheel for detecting the tire air pressure, and whether or not the vehicle has stepped on the level difference based on the detection signal from the pressure sensor 1. ECU 5 (mounting determination means) for determining whether the detection signal is equal to or greater than a predetermined threshold, and the maximum value of the change rate of the detection signal is equal to or less than another predetermined threshold If it is, it is determined that the vehicle has climbed a step.

  According to this configuration, among the changes in the tire air pressure of the wheels that are in direct contact with the step, the step is judged only by a large and slow change in pressure. Ascending can be prevented from being determined as stepping up, and stepping up can be accurately detected.

Further, according to this reference example , the detection signal detected by the pressure sensor 1 is transmitted to the transmitter 2 (transmission means).
Is wirelessly transmitted and received by the receiver 3 (receiving means) installed on the vehicle body side and input to the ECU 5,
The ECU 5 determines whether or not the vehicle has climbed the step based on the tire air pressure detection signal received by the receiver 3 and the rate of change of the detection signal. Therefore, since the pressure sensor 1 can be installed in the tire 5 which is a place where the tire air pressure can be directly measured, it is possible to make a ride determination using a signal obtained by directly measuring the tire air pressure, and an accurate determination can be made.
<First embodiment>
In the first embodiment, only the step climb determination method shown in FIG. 3 in the first reference example is different. As shown in FIG. 9, when riding on a predetermined level difference, the tire pressure increases depending on the speed even if the level of the level difference is the same. The present embodiment is configured such that even when the speed is different, it is possible to determine whether or not the step has been climbed based on the difference in height of the step.

Here, the step is regarded as an object having an effective mass M, and the tire is considered to collide with an object (step) having an effective mass M at a certain speed V. Here, the “effective mass” refers to a mass calculated using a relationship between momentum and impulse from a signal detected by a pressure sensor at the time of collision. At this time, if the detected wheel speed at the time of collision is V, the duration of the collision is Δt, and the applied load is F, a well-known relational expression of momentum and impulse,
MV = FΔt (1)
Therefore, the effective mass is M = FΔt / V.

When a tire collides with an object having a certain effective mass M at a certain collision speed V, the pressure sensor 1 detects an increase in tire air pressure by the collision load F. Since the pressure sensor 1 substantially detects a load, the pressure detection value can be handled in the same manner as the load. The value of the pressure sensor 1 uses an average value for a predetermined time of several milliseconds to several tens of milliseconds, and if integration is performed as an integration time for averaging the duration Δt, the effective mass is calculated from the equation (1). ,
M = (∫P (t) dt) / V (2)
Can be obtained. Note that the coefficients are ignored. Further, although the speed V depends on time, a value taken in as a vehicle speed detection value by the wheel speed sensor 4 is used. Therefore, when calculating an effective mass, it is treated as a constant and excluded from integration.

  Here, assuming that the effective mass M is proportional to the height of the step, the threshold value Mth is experimentally obtained, and the step climb is determined based on this threshold value. It can be determined that the ride can be judged. For example, even if a small step is passed at a high speed and a large tire pressure is detected, it is divided by the magnitude of the speed, so that it is not erroneously detected that the step is climbed.

  Hereinafter, description will be given according to the flowchart shown in FIG. First, the wheel rotational speed V and the time integral value of tire air pressure (） P (t) dt) are read (S401). Next, the effective mass Mef is obtained by dividing the time integral value of tire air pressure (∫P (t) dt) by the wheel rotational speed V (S402). This effective mass Mef is compared with a threshold value Mth1 (S403). When the effective mass Mef is larger than the threshold value Mth, it is determined that the step is climbed. Note that the tire air pressure integral value (∫P (t) dt) is obtained for a predetermined time.

  As is apparent from the above detailed description, according to the present embodiment, the ECU 5 determines that the vehicle has climbed the step when the value obtained by dividing the time integral value of the signal by the vehicle speed is equal to or greater than a predetermined threshold value. It is characterized by doing.

According to this configuration, of the changes in the tire air pressure of the wheels that are in direct contact with the step, the effect on the tire air pressure detected by the speed can be reduced, so it is possible to determine only by the size of the step and accurately detect the step climb It becomes possible to do.
<Second Embodiment>
The second embodiment is a wheel during traveling to be able to detect that fell to the recess, by modifying the above Symbol first embodiment, in addition to the wheel rides on the step It is also possible to detect that the wheel has fallen into the depression.

  There are many unpaved roads on the earth where a part of the road flows out of the shoulders due to heavy rain, and many paved roads where the road surface sinks due to heavy rain. When driving on a road where a part of the shoulder has flowed out in this way, the wheel may be dropped in a place where it accidentally collapsed and collapsed, or after it has collapsed, it becomes a deep puddle, and it is mistaken for a normal puddle. May put wheels in. In such a case, when receiving an impact, the collision detection acceleration sensor (G sensor) detects a large acceleration, so the collision detection device (occupant protection device ECU) considers the vehicle collision and deploys the airbag. Sometimes. However, since the collision detection device considers the airbag deployment time and starts deployment of the airbag at an acceleration smaller than the maximum acceleration at the time of the collision in the initial stage of the collision, The maximum value of the impact when a wheel is put in the vehicle is not as great as at the time of a collision due to an accident, and the driver and passenger are often safe even if the airbag is not opened. When the airbag is opened, an impact is applied to the occupant, the opened airbag hinders driving, and a repair fee for the airbag is generated.

  For example, when the wheel falls into the depression 8 as shown in FIG. 11, the tire is greatly deformed and the tire air pressure increases. This is considered in the same way as the step-up determination, and a depression determination threshold value is provided to detect that the depression has fallen into the depression 8. The ECU 5 uses the determination result as a depression detection signal to pass through the CAN. Send to each unit. As a determination method, when the tire pressure signal exceeds the depression detection threshold, or when the tire pressure signal falls below another depression detection threshold based on the high frequency component of the tire pressure signal, or When the value obtained by dividing the time integrated value of the tire pressure signal by the vehicle speed exceeds a threshold value for detecting another depression, that is, the value based on the tire pressure detection signal is a predetermined depression detection threshold. When the value changes across the values, the ECU 5 determines that the wheel has fallen into the depression.

Hereinafter, description will be given according to the flowchart shown in FIG. The flowchart of FIG. 12 corresponds to FIG. 4 of the first reference example . First, the wheel rotation speed V and the tire pressure P are read (S501). Next, the wheel rotation speed V is compared with the threshold value Vth4 (S502). When the wheel rotational speed V is smaller than the threshold value Vth4, the tire air pressure P is compared with the threshold value Pth4 (S503) . When the wheel rotational speed V is larger than the threshold value, it is determined that the depressed portion is depressed . Similarly, in the first embodiment, it is possible to determine that the object has fallen into the depressed portion by providing a threshold value.

  Based on this signal, the occupant protection device ECU prevents the airbag from being deployed for a predetermined time, or changes the threshold for collision detection for a predetermined time, and determines whether the airbag can be deployed at a higher acceleration. What should I do? It should be noted that each depression threshold value at this time corresponds to a pressure change sufficiently larger than the threshold value for detecting a step in each embodiment. For example, when the vehicle hits a wall at a high speed and hits a step for stopping a car, the airbag is deployed to ensure safety. In the present specification, it may be assumed that the vehicle has climbed the step when the wheel has climbed the step, and that the vehicle has fallen into the depressed portion when the wheel has fallen into the depressed portion.

  As is apparent from the above description, according to the present embodiment, the pressure sensor 1 (pressure detection means) that is provided in the tire and detects the tire air pressure, and the depression is depressed based on the detection signal from the pressure sensor 1. ECU 5 (mounting determination means) for determining whether or not the vehicle is depressed, and the ECU 5 compares the value based on the tire air pressure detection signal with a predetermined depressed portion detection threshold value to determine whether or not the depressed portion is depressed. It is characterized by determining.

  According to this configuration, since the detection is based on the tire air pressure of the wheel that is in direct contact with the depressed portion, it is possible to accurately detect the depressed portion. For example, unnecessary deployment of the airbag is ensured while ensuring safety. Can be prevented.

  Further, according to the present embodiment, the transmitter 2 (transmission means) wirelessly transmits the detection signal detected by the pressure sensor 1, and the receiver 3 (reception means) installed on the vehicle body side receives and inputs it to the ECU 5. Then, the ECU 5 determines whether or not the vehicle has climbed the step based on the tire air pressure detection signal received by the receiver 3 and the change rate of the detection signal. Therefore, since the pressure sensor 1 can be installed in the tire 5 which is a place where the tire pressure can be directly measured, it is possible to determine whether or not the tire sensor has fallen into the depression by a signal obtained by directly measuring the tire pressure. Accurate judgment can be made.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

  The step climb determination is performed for at least the front wheels, but needless to say, it may be performed for all the wheels. It is also possible to detect a step ride on a step on the inside of the wheel base when moving forward and a step ride on a step on the outside of the wheel base when moving backward.

  Although the pressure sensor, the transmitter, and the battery are provided in the air chamber of the tire, a detection hole may be provided in the rim portion of the wheel, and the transmitter or the like may be provided on the inner peripheral side of the rim portion outside the air chamber. In this way, since the battery can be replaced relatively easily when the battery is consumed, the data transmission frequency can be increased.

  The transmission interval is set at a predetermined interval. However, when the tire pressure changes rapidly, the transmission interval may be shortened and the transmitter may determine to increase the transmission frequency.

  As the pressure sensor, transmitter, and receiver, those provided for the direct TPMS may be used if available. Further, a battery-less type may be used. Further, as long as the tire pressure can be detected in a low speed range including a stop, an indirect TPMS or ABS sensor or other sensor that mainly transmits a signal through a wired transmission line may be used. In this case, the pressure of the tire may be indirectly estimated instead of the pressure sensor, or a wheel speed sensor may be included. In addition, although the ECU is independent, at least a part of the functions of the ECU is provided in the ESC-ECU that is a control unit of the skid prevention mechanism, or in the TPMS-ECU that is the control unit of the TPMS. It may be provided in the ECU.

  Although the tire side is a transmitter and the vehicle body side is a receiver, both may be transmitters / receivers and have both a transmission function and a reception function. Because it can communicate in both directions, if a request to increase the transmission frequency is transmitted from the vehicle body side according to various conditions and the transmission frequency of data from the tire side is increased accordingly, the determination accuracy can be improved. Can do. Further, if data transmission is stopped while the vehicle is stopped, battery consumption of the tire-side transceiver can be reduced.

DESCRIPTION OF SYMBOLS 1 Pressure sensor 2 Transmitter 3 Receiver 4 Wheel speed sensor 5 ECU
6 Tire 7 Step 8 Depressed part 10 Step climb detection device

Claims (7)

A step climb detection device that detects that a vehicle has climbed a step,
Pressure detecting means provided on the wheel for detecting tire air pressure;
Riding determination means for determining whether or not the vehicle has climbed a step based on a detection signal from the pressure detecting means;
Equipped with a,
A wheel speed signal indicating the wheel rotation speed is input,
The step-up determination device is characterized in that when the value obtained by dividing the time integral value of the detection signal by the wheel rotation speed is larger than a predetermined threshold value, the step-up determination unit determines that the step has been reached . The ride determining means, wherein a value based on the detection signal of the tire pressure, in claim 1, with a predetermined depression detection threshold, and judging whether or not it falls into recess Level difference detection device. The pressure detecting means is provided on at least a front wheel of a vehicle,
The run-up determining means, step run detection device according to claim 1 or 2, characterized in that executing whether riding on the step, or the determination of whether it falls into recess for each wheel. Transmitting means for wirelessly transmitting a tire air pressure detection signal by the pressure detecting means;
Receiving means for receiving the tire air pressure detection signal wirelessly transmitted by the transmitting means;
Have
The climbing determination unit determines whether or not the rider has climbed a step based on the tire pressure detection signal received by the receiving unit, or determines whether or not the rider has fallen into a depression. Item 4. The step climbing detection device according to any one of Items 1 to 3 . 5. The step climbing detection apparatus according to claim 4 , wherein the pressure detection unit, the transmission unit, and the reception unit are shared with a pressure detection unit, a transmission unit, and a reception unit of a tire air pressure monitoring system, respectively. The step climbing detection device according to claim 4 or 5 , wherein the pressure detection means and the transmission means are provided in an air chamber of the tire. The step climbing detection device according to claim 4 or 5 , wherein the pressure detection means and the transmission means are provided on an inner peripheral side of a rim portion of a wheel.

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