JP2006281961A - Brake control device for vehicle and brake device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize a behavior of a vehicle on a split road surface in a brake device for the vehicle performing an antilock control. <P>SOLUTION: This brake control device 100 for the vehicle is provided with a gentle pressure intensifying control part 25a for gently increasing braking force of a wheel having smaller slip amount when a difference of slip amount of left and right wheels exceeds a first reference value, a first braking force reducing part 25b for lowering the braking force of the wheel having smaller slip amount by first reducing amount when the difference of slip amount of the left and right wheels exceeds a second reference value larger than the first reference value, and a second braking force reducing part 25c for lowering braking force of the wheel having smaller slip amount by second reducing amount when the difference of slip amount of the left and right wheels exceeds a third reference value larger than the second reference value, in an antilock control part 25. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicular brake control device and a vehicular brake device including so-called antilock control means for independently controlling the braking force of left and right wheels to prevent excessive slip during braking.

In recent years, brake devices for vehicles have become highly functional, and brake devices with an antilock control function for preventing wheels from slipping excessively on low μ roads have been widely used. As an application of the anti-lock control technique, a technique for improving vehicle stability on a so-called split road surface in which the left and right wheels straddle different road surface friction coefficients is also known.
On the split road surface, if the braking force is applied to the left and right wheels in the same way, a difference in braking force is generated between the left and right wheels, and the vehicle body tends to spin so that the low μ road side where the braking force is small advances forward. is there.
As means for solving this, when the speed difference between the left and right wheels is small, the brake fluid pressure of the wheel on the high μ road side is gradually increased with respect to the brake fluid pressure (braking force) on the wheel on the low μ road side, and the speed difference is large. In some cases, the difference between the left and right braking force is not increased too much by forcibly reducing the brake fluid pressure of the high μ road wheel when the low μ road wheel falls below a predetermined speed. (For example, refer to Patent Document 1).

JP-A-6-144189

However, according to the anti-lock control of Patent Document 1, it is possible to suppress the spin of the vehicle body by forcibly reducing the brake fluid pressure of the wheels on the high μ road side, but when the difference between the left and right wheel speeds increases. In other words, the braking force suddenly decreases, and the braking distance is unnecessarily extended.
The present invention has been made in view of such a background, and an object of the present invention is to provide a vehicle brake device that stabilizes the behavior of the vehicle.

  In order to solve the above-described problems, the present invention provides a vehicle brake control device including anti-lock control means for performing anti-lock control on each of left and right wheel brakes. The vehicle brake control device includes slip detection means for detecting a slip amount of the wheel for each of the left and right wheels, and the anti-lock control means has a difference in slip amount between the left and right wheels exceeding a first reference value. In this case, when the difference between the slip amount of the left and right wheels exceeds the second reference value that is larger than the first reference value, the slip amount is increased. When the difference between the first braking force reduction unit that reduces the braking force of the smaller wheel by the first reduction amount and the slip amount of the left and right wheels exceeds a third reference value that is greater than the second reference value, the slip amount is And a second braking force reduction unit that reduces the braking force of the smaller wheel by a second reduction amount.

According to such a vehicle brake control device, the braking force of the wheels on the high μ road surface side is reduced stepwise according to the slip amount of the left and right wheels, for example, the difference between the slip ratio and the wheel speed. That is, the first braking force reduction unit reduces the one-step braking force and monitors the difference in slip amount while braking with the braking force as it is for a while. Thereafter, if the difference in the slip amount does not increase to the second reference value, the braking can be performed without reducing the braking force of the wheel on the high μ road surface as much as possible by braking with the braking force as it is. On the other hand, when the difference in slip amount exceeds the second reference value, the stability of the vehicle can be ensured by further reducing the braking force of the wheels on the high μ road side.
As described above, in the present invention, an unnecessary decrease in the braking force can be suppressed by gradually decreasing the braking force on the high μ road surface side.

In addition, the vehicle brake control device of the present invention further includes vehicle speed detection means for detecting a vehicle speed, and at least one of the first reference value, the second reference value, and the third reference value is a vehicle speed. The anti-lock control means acquires the first reference value, the second reference value, and the third reference value according to a vehicle speed, and executes anti-lock control. It is good.
Alternatively, the vehicle brake control device of the present invention further includes vehicle speed detection means for detecting a vehicle speed, and at least one of the first reduction amount and the second reduction amount changes according to the vehicle speed. The anti-lock control means may be configured to acquire the first reduction amount and the second reduction amount according to the vehicle speed and execute anti-lock control.
By setting the timing and the braking force according to the vehicle speed in this way, it is possible to perform appropriate braking according to the vehicle speed.

  The above-described vehicle brake control device further includes a turn detection unit that detects turning of the vehicle, and the antilock control unit is configured to detect the first braking force reduction unit when turning satisfying a predetermined criterion is detected. The braking force may not be reduced by at least one of the second braking force reduction units.

  According to this configuration, when the vehicle is turning, the occurrence of slip due to a decrease in the load on the inner ring can be suppressed.

The second reduction amount is preferably larger than the first reduction amount.
By setting in this way, when the braking force reduction by the first braking force reducing means is insufficient, stabilization of the vehicle behavior can be achieved quickly.

The first reduction amount, the second reduction amount, and the third reference value can take various values depending on the vehicle speed.
For example, at least one of the first reduction amount and the second reduction amount can be set to become a smaller value as the vehicle speed increases in a low speed region that is equal to or lower than a predetermined vehicle speed. In this way, by giving at least one of the first reduction amount and the second reduction amount a negative correlation with the vehicle speed in the low speed range, importance is attached to the stability of the vehicle in the low speed range, and vibration is suppressed. Can do.
Further, at least one of the first reduction amount and the second reduction amount may be set to be a constant value regardless of the vehicle speed in a region higher than a predetermined vehicle speed. Thus, by making the first reduction amount and the second reduction amount constant in the high speed range, it is possible to prevent the braking force from being unnecessarily reduced when the vehicle is at high speed.

  In addition, by setting the third reference value to be a constant value regardless of the vehicle speed in a region higher than the predetermined vehicle speed, the vehicle can be stabilized at an early stage in the high speed region to improve operation feeling. Can do.

The present invention provides a vehicle brake device comprising the vehicle brake control device described above and a hydraulic brake provided on each wheel. In this vehicle brake device, the first braking force reduction unit and the second braking force reduction unit reduce the braking force by reducing the brake fluid pressure of the hydraulic brake of each wheel.
By using the hydraulic brake in this way, the braking force can be quickly reduced when the brake hydraulic pressure of the wheel on the high μ road surface side is forcibly reduced.

The present invention also provides a vehicle brake device comprising the above-described vehicle brake control device, and a hydraulic brake and a regenerative brake provided on each wheel. In the vehicle brake device, one of the first braking force reduction unit and the second braking force reduction unit operates the hydraulic brake, and the other operates the regenerative brake.
Even when different types of brakes are combined in this way, similar effects can be achieved.

  According to the present invention, it is possible to stabilize the behavior of the vehicle and prevent the braking force from being reduced unnecessarily.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
[First Embodiment]
FIG. 1 is a configuration diagram of a vehicle brake device according to a first embodiment of the present invention, FIG. 2 is a hydraulic circuit diagram of a hydraulic unit, and FIG. 3 is a first embodiment. It is a block diagram of the brake device for vehicles concerning a form, and Drawing 4 (a) is an example of judgment standard value setting information, and (b) is a graph which shows an example of reduction amount setting information.
As shown in FIG. 1, the vehicle brake device is a brake FR, FL, RR, RL that is a hydraulic brake provided on each wheel, and a vehicle that controls the operation of these brakes FR, FL, RR, RL. And the brake control device 100 for a vehicle.

  Each brake FR, FL, RR, RL is composed of, for example, a disk D and a wheel cylinder H. The wheel cylinder H is a hydraulic device that converts the brake hydraulic pressure generated by the master cylinder M and the vehicle brake control device 100 into the operating force of the brakes FR, FL, RR, RL provided on each wheel T. Each is connected to the hydraulic unit 10 of the vehicle brake control device 100 via a pipe. In both cases of normal brake and anti-lock brake control, brake fluid is supplied to the wheel cylinder H via the vehicle brake control device 100.

The vehicle brake control device 100 includes a hydraulic unit 10, a control device (ECU) 20, and various sensors for detecting the behavior of the vehicle CR.
The vehicle CR includes a wheel speed sensor 91 that detects the rotational speed of the wheel T, a steering angle sensor 92 that detects the steering angle of the steering ST, and a centrifugal force (acceleration) that acts in the lateral direction of the vehicle CR. A lateral G sensor 93 for detecting, a yaw rate sensor 94 for detecting a turning angular velocity, and an acceleration sensor 95 for detecting acceleration in the longitudinal direction of the vehicle are provided.
The wheel speed sensor 91 corresponds to vehicle speed detection means, and the steering angle sensor 92 and the yaw rate sensor 94 correspond to turning detection means.

Each of the sensors 91 to 95 is connected to the control device 20 and outputs the detected information to the control device 20. 4
The hydraulic unit 10 is connected to the master cylinder M so that the hydraulic pressure generated in the master cylinder M by the operation of the brake pedal P is transmitted.
The control device 20 includes, for example, a CPU, a RAM, a ROM, and an input / output circuit, and inputs from the wheel speed sensor 91, the steering angle sensor 92, the lateral G sensor 93, and the yaw rate sensor 94, and a program stored in the ROM. Control is performed by performing arithmetic processing based on the data.

  Next, the configuration of the hydraulic unit 10 will be briefly described with reference to FIG. In FIG. 2, a solid line connecting various components in the hydraulic unit 10 indicates an oil passage formed in the hydraulic unit 10.

  As shown in FIG. 2, the hydraulic pressure unit 10 is disposed between a master cylinder M that generates brake hydraulic pressure corresponding to the pedaling force applied by the driver to the brake pedal P and the brakes FR, FL, RR, and RL. ing. The two output ports M1, M2 of the master cylinder M are connected to the inlet port 121 of the hydraulic unit 10, and the outlet port 122 of the hydraulic unit 10 is connected to each brake FR, FL, RR, RL. Further, since the oil passage is normally connected from the inlet port 121 to the outlet port 122 in the hydraulic pressure unit 10, the depression force of the brake pedal P is transmitted to each wheel brake FL, RR, RL, FR. It has become so.

  The oil path starting from the output port M1 leads to the wheel brake FL on the left side of the front wheel and the wheel brake RR on the right side of the rear wheel, and the oil path starting from the output port M2 is set to the wheel brake FR on the right side of the front wheel and the wheel brake on the left side of the rear wheel. It leads to RL.

  In the oil passage from the inlet port 121 to each brake FR, FL, RR, RL, an inlet valve 1 which is a normally open solenoid valve is provided. In the oil passage between the inlet valve 1 and each brake FR, FL, RR, RL, the brake fluid pressure of each brake FR, FL, RR, RL (wheel cylinder H) is mastered when anti-lock control is performed. An open path for returning to the cylinder M side is provided. In this open path, an outlet valve 2, a reservoir 3, and a pump 4 are provided in order from each brake FR, FL, RR, RL to the master cylinder M.

  The outlet valve 2 is a normally closed solenoid valve. Normally, the outlet valve 2 is closed so that the hydraulic pressure from the master cylinder M goes to the brakes FR, FL, RR, RL. In the anti-lock control, the brake FR, FL , RR, RL are opened to lower the hydraulic pressure.

  The reservoir 3 has a function of temporarily storing the brake fluid discharged from the outlet valve 2.

  The pump 4 is a device that sends brake fluid toward the master cylinder M side by the operation of the motor 9. The pump 4 operates during anti-lock control and sends brake fluid to the inlet valve 1 side, and adjusts the hydraulic pressure of each brake FR, FL, RR, RL in cooperation with the inlet valve 1 and the outlet valve 2.

  Each inlet valve 1 is provided with a check valve 1a in parallel. Each check valve 1a is allowed to flow brake fluid from the brake FR, FL, RR, RL side toward the master cylinder M side. Further, a check valve 3 a that allows only the flow of brake fluid from the brakes FR, FL, RR, RL to the master cylinder M is also provided between the reservoir 3 and the pump 4.

The above inlet valve 1, outlet valve 2, and pump 4 are operated by signals from the control device 20.
Normally, the inlet valve 1 is opened and the outlet valve 2 is closed, so that the hydraulic pressure applied from the master cylinder M is transmitted to the brakes FR, FL, RR, and RL through the inlet valve 1.

  On the other hand, at the time of anti-lock control, the hydraulic pressure of each brake FR, FL, RR, RL is reduced, held, or increased by cooperating the inlet valve 1, the outlet valve 2, and the pump 4. By closing the inlet valve 1 and opening the outlet valve 2, the brake fluid is discharged from the brakes FR, FL, RR, RL via the outlet valve 2, and the hydraulic pressure is reduced. Moreover, the fluid pressure is maintained by closing both the inlet valve 1 and the outlet valve 2. Further, by opening the inlet valve 1 and closing the outlet valve 2, the hydraulic pressures of the brakes FR, FL, RR, and RL are increased by the hydraulic pressure applied from the brake pedal P.

Next, the configuration of the control device 20 will be described with reference to FIG.
The control device 20 includes an arithmetic processing unit 21 and a storage unit 29. The arithmetic processing unit 21 is a so-called central processing unit (CPU), and implements various control functions by reading and executing the control program 29a stored in the storage unit 29.
Further, the control device 20 has an input / output port (not shown) and receives detection signals from the wheel speed sensor 91, the steering angle sensor 92, the lateral G sensor 93, the yaw rate sensor 94, and the acceleration sensor 95, and the hydraulic pressure. Signals for commanding the operation to the inlet valve 1, the outlet valve 2 and the motor 9 of the unit 10 are output.

The memory | storage part 29 is ROM, RAM, a hard disk, etc., The kind is not ask | required. The storage unit 29 stores a control program 29a, determination reference value setting information 29b, and reduction amount setting information 29c.
The control program 29a is a program for realizing each function in the arithmetic processing unit 21 to be described later.

As shown in FIG. 4A, the determination reference value setting information 29b defines a difference in slip ratio as a determination reference value for changing the control operation of the control device 20 in relation to the vehicle speed. The determination reference values include a first reference value, a second reference value, and a third reference value, and the values increase in this order at the same vehicle speed. The first reference value is a constant value that does not depend on the vehicle speed, and the second reference value and the third reference value are set to increase as the vehicle speed increases.
When the difference between the slip ratios of the left and right wheels (details will be described later) is less than or equal to the first reference value, normal antilock control is performed, and the brake hydraulic pressure is between the first reference value and the second reference value. Slow pressure increase control is performed, and between the second reference value and the third reference value, the first-stage forced pressure reduction control (shown as “forced pressure reduction 1”) of the brake fluid pressure is performed, and the third reference value or more Then, the second-stage forced pressure reduction control (shown as “forced pressure reduction 2”) of the brake fluid pressure is performed.

  As shown in FIG. 4B, the reduction amount setting information 29c reduces the amount of brake fluid pressure to be reduced during the forced pressure reduction control, specifically, the opening time of the outlet valve 2 in relation to the vehicle speed v. I remember it as a quantity. The reduction amount includes a first reduction amount and a second reduction amount. If the vehicle speed is the same, the second reduction amount is set higher than the first reduction amount. Further, the first reduction amount and the second reduction amount are both set to increase as the vehicle speed increases.

  The arithmetic processing unit 21 illustrated in FIG. 3 includes a vehicle speed calculation unit 21a, a slip rate calculation unit 21b, a determination reference value setting unit 21c, a reduction amount setting unit 21d, and an antilock control unit 25 as functional units.

The vehicle speed calculation unit 21 a estimates the speed of the vehicle CR based on the signal input from the wheel speed sensor 91. For example, in the case of a front wheel drive vehicle or a rear wheel drive vehicle, the vehicle speed can be estimated by converting the rotation speed of the wheel T of the non-drive wheel into the vehicle speed v. In the case of a four-wheel drive vehicle, the vehicle speed may be estimated in consideration of the acceleration input from the acceleration sensor 95 in addition to the vehicle speed v estimated from the wheel speed.
The wheel speed sensor 91 and the vehicle speed calculation unit 21a correspond to vehicle speed detection means.

The slip ratio calculation unit 21b calculates the slip ratios SL _R and SL _L for the left and right wheels T from the estimated vehicle speed v and the left and right wheel speeds v _R and v _L as in the following expressions (1) and (2). Is calculated.
SL _R = (v−v _R ) / v × 100 (%) (1)
SL _L = (v−v _L ) / v × 100 (%) (2)

  The determination reference value setting unit 21 c is a part that acquires a determination reference value from the determination reference value setting information 29 b in the storage unit 29 based on the vehicle speed v.

  The reduction amount setting unit 21 d is a part that acquires the reduction amount from the reduction amount setting information 29 c in the storage unit 29 based on the vehicle speed v.

  The antilock control unit 25 (antilock control means) includes a slow pressure increase control unit (slow increase control unit) 25a, a first braking force reduction unit 25b, and a second braking force reduction unit 25c, and has a slip ratio SL. By monitoring this, normal antilock control is also performed.

When the slow pressure increase control unit 25a enters the anti-lock control and the difference ΔSL = | SL _R −SL _L | between the slip ratios SL _R and SL _L of the left and right wheels T is larger than the first reference value, Specifically, when located between the first reference value and second reference value, the slip rate SL _R, by pressure Yuruzo the brake fluid pressure of the wheel of the smaller of SL _L, slow increase the braking force It is a means to make.
Slip ratio SL _R of the right and left wheels T, the difference ΔSL of SL _L is may take the difference in the left and right wheels among the front left and right wheels or between the rear wheels, the average of the slip ratio of the front and rear right wheel, the front and rear left You may take a difference with the average of the slip ratio of a wheel.
Specifically, the control for slowly increasing the braking force may be instructed to the hydraulic unit 10 so that the inlet valve 1 is intermittently opened at predetermined intervals while the outlet valve 2 is kept closed.

When the vehicle CR is not turning, the first braking force reduction unit 25b has a first reduction amount if the slip ratio difference ΔSL between the left and right wheels T exceeds a second reference value that is greater than the first reference value. Only reduce the brake fluid pressure. More specifically, when the slip ratio difference ΔSL is between the second reference value and the third reference value, the brake fluid pressure is reduced by the first reduction amount.
Specifically, the first-stage forced depressurization method may be instructed to continue to send the pulse signal for the valve opening time acquired as the first reduction amount and to open the outlet valve 2.

When the vehicle is not turning, the second braking force reduction unit 25c brakes by the second reduction amount if the difference ΔSL between the left and right wheels exceeds the third reference value that is greater than the second reference value. Reduce fluid pressure.
Specifically, the second-stage forced pressure reduction may be instructed to open the outlet valve 2 for the valve opening time acquired as the second reduction amount.

  Note that the right wheel control unit 10R and the left wheel control unit 10L shown in the hydraulic unit 10 in FIG. 3 are an inlet valve 1 and an outlet valve of the system connected to the right wheel and the left wheel in the hydraulic unit 10, respectively. 2 corresponds to the pump 4 and the motor 9.

  The operation of the vehicle brake device configured as described above will be described with reference to FIGS. FIG. 5 is a flowchart for explaining the operation of the vehicle brake device according to the first embodiment. FIG. 6 shows a change in brake fluid pressure, a change in vehicle speed v, an operation of the low μ side valve, and a high μ side valve. It is the timing chart which showed the operation | movement side by side.

As shown in FIGS. 5 and 6, when the vehicle CR is traveling, the vehicle speed calculation unit 21a calculates the vehicle speed v as needed, and the slip rate calculation unit 21b calculates the slip rate SL. (S1). Then, the determination reference value setting unit 21c acquires a determination reference value (first reference value, second reference value, and third reference value) according to the vehicle speed v (S2). When the difference ΔSL between the left and right wheels does not exceed the first reference value (S3, No), the antilock control unit 25 performs normal antilock control (S4). Since the slip ratio (for example, SL _L ) of the low μ wheel begins to increase at time t _{1 to} t _{2 in} FIG. 6, the low μ wheel wheel is connected to the decompression side (inlet valve) at an appropriate timing. 1 is closed and the outlet valve 2 is opened), indicating that the normal antilock control has been entered.

On the other hand, when the difference ΔSL in the slip ratio exceeds the first reference value (S3, Yes), it is determined whether or not the difference ΔSL in the slip ratio exceeds the second reference value (S5).
When the difference ΔSL in the slip ratio does not exceed the second reference value (S5, No), the slow pressure increase control unit 25a enters the slow pressure increase control (S6). That is, as shown in time t ₂ ~t ₃ shown in FIG. 6, the wheel slip ratio SL _L of the low μ side begins to fill up, the difference of slip ratio ΔSL becomes greater, a high braking force as much as possible To increase the braking force of the wheel on the high μ side, the valve on the wheel on the high μ side is actuated gradually (the inlet valve 1 is opened and the outlet valve 2 is closed).

When the low μ side wheel does not stop locking, the slip ratio difference ΔSL further increases, and when the slip ratio difference ΔSL exceeds the second reference value (S5, Yes), the slip ratio difference It is determined whether ΔSL is larger than the third reference value (S7). When the difference ΔSL in the slip ratio does not exceed the third reference value (S7, No), the reduction amount setting unit 21d acquires and sets the first reduction amount according to the vehicle speed v (S8). In this case, the time t _{3 to} t ₄ shown in FIG. 6 is set, and the first-stage forced pressure reduction is set on the high μ side. On the other hand, if the difference ΔSL in the slip ratio exceeds the third reference value (S7, Yes), the reduction amount setting unit 21d acquires and sets the second reduction amount according to the vehicle speed v (S9). ). In this case, a time t ₅ ~t ₇ shown in FIG. 6, the forced pressure reduction set in the second stage the high μ side is performed.
Then, the anti-lock control unit 25 actively turns the steering based on the steering angle detected by the steering angle sensor 92 and the yaw rate detected by the yaw rate sensor 94, and the vehicle CR turns at a yaw rate equal to or higher than a predetermined value. If it is determined that it has been determined (S10, Yes), the execution of the forced pressure reduction control is stopped (S12). On the other hand, when the vehicle CR is not turning at a yaw rate equal to or higher than the predetermined value (S10, No), the forced pressure reduction control is executed to reduce the braking force of the wheels on the high μ side by the set reduction amount (S11). . That is, as shown at times t ₃ and t ₅ in FIG. 6, control for forcibly reducing the hydraulic pressure of the brake fluid is performed.

Thus, according to the vehicle brake device (vehicle brake control device 100) of the present embodiment, when the difference ΔSL in the slip ratio between the left and right wheels is between the first reference value and the second reference value. By keeping the degree of forced decompression small and observing the behavior of the vehicle, braking of the vehicle CR is efficiently performed with the wheel on the high μ side, and the slip of the wheel on the low μ side (lock tendency) Wait for recovery. And if it recovers, keep the fluid pressure as it is or cancel the anti-lock control, and if it does not recover, recover the wheel on the high μ side with a second reduction amount larger than the first reduction amount. A second-stage forced pressure reduction is applied to the brake to ensure the stability of the vehicle behavior.
Therefore, in the vehicle brake device of the present embodiment, when the increase in the slip ratio difference ΔSL is not settled, the stability of the behavior of the vehicle CR can be ensured and the stable steering performance can be realized.

The present invention is not limited to the first embodiment described above, and can be implemented with appropriate modifications.
For example, in the first embodiment, the slip ratio is used as the slip amount, but the speed difference between the left and right wheels can also be used as the slip amount, and other physical quantities that mean the slip amount can also be used.

In the first embodiment, the determination reference value setting information 29b is set such that each of the first reference value, the second reference value, and the third reference value changes according to the vehicle speed. The reference value may be set to a constant value without depending on the vehicle speed. Similarly, in the reduction amount setting information, each of the first reduction amount and the second reduction amount is set to change according to the vehicle speed. However, these reduction amounts are not dependent on the vehicle speed. , It may be set to a constant value.
In the first embodiment, whether or not there is a turn is determined based on the steering angle acquired from the steering angle sensor 92 and the yaw rate acquired from the yaw rate sensor 94. However, the steering angle detected by the steering angle sensor 92 is determined. Only or the yaw rate acquired from the yaw rate sensor 94 can be used to determine turning, or the presence or absence of turning can be determined based on the lateral acceleration detected by the lateral G sensor 93. Furthermore, the structure which stops forced pressure reduction control at the time of turning can be abbreviate | omitted.

Note that the first reference value, the second reference value, and the third reference value are not limited to being set as a map, as shown in FIG. 4A, and may be set as functions. For example, in the case of the second reference value (referred to as TH2) of FIG.
(Where k and a are constants)
It can be expressed as. The first reference value and the third reference value, and the first reduction amount and the second reduction amount shown in FIG. 4B can also be expressed by the same linear function.

  Next, an embodiment according to a modification of the present invention will be described. In the following embodiment, only a different part from 1st Embodiment is demonstrated.

[Second Embodiment]
FIG. 7 is a table showing determination reference value setting information and reduction amount setting information of the vehicle brake device according to the second embodiment.
As shown in FIG. 7, the determination reference value setting information 29b (second reference value and third reference value) and the reduction amount setting information 29c (first reduction amount and second reduction amount) can be stored in a table. It is.
In the table of FIG. 7, the second reference value and the third reference value are constant values for each speed range, and a larger reference value is set as the vehicle speed increases. Further, the valve opening time indicating the first reduction amount and the second reduction amount is basically set to a larger value as the vehicle speed becomes higher. Further, the second reduction amount is set larger than the first reduction amount.
However, the first reduction amount at 0 to 30 km / h is set to be larger than the first reduction amount at 30 to 40 km / h, which is the vehicle speed of the upper segment.
Thus, the first reduction amount and the second reduction amount do not have to be completely correlated with the vehicle speed, and can be set to appropriate values according to the speed range. As in the second embodiment, by making the first reduction amount higher in the low speed range than in the middle speed range, it is possible to ensure maneuverability according to the speed range. In other words, in the medium speed range, it is often traveling in a place where there are few obstacles, so it is possible to try to maintain braking force rather than maneuverability, but when traveling at low speeds such as urban areas, Since there are many obstacles around, it is possible to secure the maneuverability of the vehicle CR at an early stage and facilitate the operation to avoid the obstacles by setting as in the present embodiment.

[Third Embodiment]
FIG. 8A is a map showing determination reference value setting information of the vehicle brake device according to the third embodiment, and FIG. 8B is a map showing reduction amount setting information.
In the vehicle brake device according to the third embodiment, as shown in FIG. 8A, the third reference value takes a larger value as the vehicle speed v increases, but the high speed range (V2 <v). Has a constant value.
In this way, by making the third reference value constant in the high speed range, when a slip ratio difference ΔSL exceeding a certain value occurs, the second-stage forced decompression is performed to ensure the stability of the vehicle. be able to. At high speeds, the driver is sensitive to vehicle shake, so this setting allows early control of the shake and improved operation feeling, allowing the driver to perform a calm operation. Can be.

Further, as shown in FIG. 8B, when the vehicle speed is in the low speed range (v ≦ V1), the reduction amount is set so that the first reduction amount and the second reduction amount are inversely related to the vehicle speed v. In the case of a high speed range (V2 <v), both the first reduction amount and the second reduction amount can be made constant regardless of the vehicle speed v.
By setting in this way, when the vehicle speed v is equal to or less than the speed V1, priority can be given to suppression of the shake of the vehicle CR. For example, when entering a left or right turn at an intersection, yaw control according to the driver's psychology is possible even with a slight swing. Further, even when the vehicle speed v is higher than the speed V2, the yaw control is performed early, but the reduction amount is not excessively increased, so that unnecessary reduction of the braking force can be prevented.
Note that, for the reduction amount setting information whose value changes in the speed range as in the reduction amount map of FIG. 8B, a function can be defined and stored for each speed range.

[Fourth Embodiment]
FIG. 9A is a map showing reduction amount setting information of the vehicle brake device according to the fourth embodiment.
As shown in FIG. 9A, as in the third embodiment, the first reduction amount is negatively correlated with the vehicle speed v in the low speed range (v ≦ V1), and the medium speed range (V1 <v ≦ V1). V2) has a positive correlation with the vehicle speed v, and is a constant value regardless of the vehicle speed v in the high speed range (V2 <v). The second reduction amount is substantially the same as the first reduction amount in the low speed range (v ≦ V1) and the medium speed range (V1 <v ≦ V2), and is larger than the first reduction amount in the high speed range (V2 <v). The value is constant. The second reduction amount is changed so that the high speed end side of the medium speed region is gradually larger than the first reduction amount so that the second reduction amount continuously changes between the medium speed region and the high speed region. .
By setting such a reduction amount, in the low speed region and the medium speed region, the second reduction amount is reduced to ensure the braking force, and in the high speed region, a larger second reduction amount is set. The stability of the vehicle can be ensured.

[Fifth Embodiment]
FIG. 9B is a map showing reduction amount setting information of the vehicle brake device according to the fifth embodiment.
As shown in FIG. 9B, as a modification of the fourth embodiment, it is possible to set the second reduction amount to 0 in the low speed range and the medium speed high speed range. In the present embodiment, in the low speed range and the medium speed range, the second reduction amount is set to 0 with emphasis on the braking force, and the second reduction amount is a constant value larger than the first reduction amount only in the high speed range. Is set.
By setting in this way, it is possible to ensure the braking force in the low speed range and the medium speed range and to ensure the maneuverability of the vehicle in the high speed range.

The present embodiment described above is not intended to limit the present invention, and can be implemented with appropriate modifications according to specifications such as the size of the vehicle and the capacity of the brake.
For example, in the embodiment, the description has been made on the premise of a hydraulic brake, but the present invention can be similarly applied to a regenerative brake used in an electric vehicle, a hybrid vehicle, or the like, or a brake operated with a wire. It is also possible to apply a combination of a hydraulic brake and these brakes.
When the hydraulic brake and the regenerative brake are applied in combination, for example, either the braking by the first braking force reduction unit 25b or the braking by the second braking force reduction unit 25c operates the hydraulic brake. On the other hand, the regenerative brake may be operated, or a hydraulic brake and a regenerative brake may be used for both the braking by the first braking force reducing unit 25b and the braking by the second braking force reducing unit 25c.
As described above, by applying a plurality of types of brakes, the cooperation between the hydraulic brake and the regenerative brake can be improved, and the braking feeling can be improved.

It is a lineblock diagram of the brake device for vehicles concerning a 1st embodiment of the present invention. It is a hydraulic circuit diagram of a hydraulic unit. It is a block diagram of the brake device for vehicles concerning a 1st embodiment. (A) is an example of determination reference value setting information, (b) is a graph which shows the example of reduction amount setting information. It is a flowchart explaining operation | movement of the brake device for vehicles which concerns on 1st Embodiment. 7 is a timing chart showing a change in brake fluid pressure, a change in vehicle speed v, an operation of a low μ side valve, and an operation of a high μ side valve. It is a table which shows the determination reference value setting information and reduction amount setting information of the vehicle brake device which concerns on 2nd Embodiment. (A) is a map which shows the determination reference value setting information of the vehicle brake device which concerns on 3rd Embodiment, (b) is a map which shows reduction amount setting information. (A) is a map which shows reduction amount setting information of the vehicle brake device which concerns on 4th Embodiment, (b) is a map which shows reduction amount setting information of the vehicle brake device which concerns on 5th Embodiment. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inlet valve 2 Outlet valve 3 Reservoir 4 Pump 9 Motor 10 Hydraulic unit 20 Control apparatus 21 Arithmetic processing part 21a Vehicle speed calculation part 21b Slip rate calculation part 21c Determination reference value setting part 21d Reduction amount setting part 25 Antilock control part 25a Slow pressure increase control unit 25b First braking force reduction unit 25c Second braking force reduction unit 29 Storage unit 29a Control program 29b Determination reference value setting information 29c Reduction amount setting information 91 Wheel speed sensor 92 Steering angle sensor 93 Lateral G sensor 94 Yaw rate Sensor 95 Acceleration sensor 100 Brake control device for vehicle

Claims (10)

A vehicle brake control device comprising anti-lock control means for performing anti-lock control on each of the left and right wheel brakes,
Slip detection means for detecting the slip amount of the wheel for each of the left and right wheels,
The antilock control means includes
When the difference between the slip amounts of the left and right wheels exceeds the first reference value, a slowly increasing control unit that slowly increases the braking force of the wheel having the smaller slip amount;
A first braking force reduction unit that reduces the braking force of the wheel with the smaller slip amount by a first reduction amount when the difference between the slip amounts of the left and right wheels exceeds a second reference value that is greater than the first reference value;
A second braking force reduction unit that reduces the braking force of the wheel with the smaller slip amount by a second reduction amount when the difference between the slip amounts of the left and right wheels exceeds a third reference value greater than the second reference value; A vehicle brake control device comprising: Vehicle speed detecting means for detecting the vehicle speed is further provided;
At least one of the first reference value, the second reference value, and the third reference value is set to change according to vehicle speed,
2. The anti-lock control unit according to claim 1, wherein the anti-lock control unit acquires the first reference value, the second reference value, and the third reference value according to a vehicle speed, and executes anti-lock control. Brake control device for vehicles. Vehicle speed detecting means for detecting the vehicle speed is further provided;
At least one of the first reduction amount and the second reduction amount is set to change according to the vehicle speed,
2. The vehicle brake control device according to claim 1, wherein the anti-lock control unit acquires the first reduction amount and the second reduction amount according to a vehicle speed and executes anti-lock control. A turn detection means for detecting turning of the vehicle;
The antilock control means does not perform a decrease in braking force by at least one of the first braking force reduction unit and the second braking force reduction unit when a turn that satisfies a predetermined criterion is detected. The vehicle brake control device according to any one of claims 1 to 3.   The vehicular brake control device according to any one of claims 1 to 4, wherein the second reduction amount is larger than the first reduction amount.   The at least one of the first reduction amount and the second reduction amount is set so as to become a smaller value as the vehicle speed becomes higher in a low speed range equal to or lower than a predetermined vehicle speed. 6. The vehicle brake control device according to any one of items 5.   7. At least one of the first reduction amount and the second reduction amount is set so as to be a constant value in a high-speed range from a predetermined vehicle speed regardless of the vehicle speed. The vehicle brake control device according to any one of the above.   The vehicle according to any one of claims 1 to 7, wherein the third reference value is set to be a constant value regardless of the vehicle speed in a region higher than a predetermined vehicle speed. Brake control device. A vehicle brake control device according to any one of claims 1 to 8, and a hydraulic brake provided on each wheel,
The first braking force reduction unit and the second braking force reduction unit reduce the braking force by reducing the brake hydraulic pressure of the hydraulic brake of each wheel. A vehicle brake control device according to any one of claims 1 to 8, and a hydraulic brake and a regenerative brake provided on each wheel,
One of the first braking force reduction unit and the second braking force reduction unit operates the hydraulic brake, and the other operates the regenerative brake.

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