JP2001047998A - Vehicle behavior control device - Google Patents

Abstract

(57) [Problem] To enable a vehicle body speed to be calculated with high accuracy even if a driver operates a side brake separately from a brake pedal operation during execution of vehicle behavior control. SOLUTION: A vehicle behavior detecting means k for detecting a behavior of a vehicle, including a vehicle speed calculating means j for calculating a vehicle speed based on a wheel speed detected by a wheel speed sensor h; Based on the input, one of the brake pipes c
Control means m for executing vehicle behavior control for controlling the vehicle behavior by controlling the hydraulic pressure of the wheel cylinder b by connecting the control means to a control hydraulic pressure source e. The means j includes a wheel speed of a non-control wheel of a system connected to the control hydraulic pressure source e, and a wheel of a system connected to a brake operation hydraulic pressure source a on the same side as the left and right sides of the non-control wheel. The vehicle speed is calculated based on the select high wheel speed, which is the higher wheel speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle behavior control device, and more particularly, to a vehicle which generates a braking force on a desired wheel when the vehicle becomes unstable due to a so-called oversteer state. The present invention relates to a vehicle behavior control device that executes a vehicle behavior control for generating a yaw moment in a direction for suppressing a change in the attitude of the vehicle.

[0002]

2. Description of the Related Art Conventionally, the behavior of a vehicle is detected, and when the vehicle is in an unstable state such as oversteer exceeding a predetermined level, the hydraulic pressure of a wheel cylinder of each wheel is increased independently of each other. 2. Description of the Related Art A vehicle behavior control device that executes vehicle behavior control that suppresses undesired behavior is known. As such an apparatus, for example, an apparatus described in Japanese Patent Application Laid-Open No. 9-315277 is known.

In this prior art, brake piping is divided into two systems (a so-called X piping) of a left front wheel and a right rear wheel and a right front wheel and a left rear wheel, and only one of the two systems is used for controlling the vehicle behavior control. It is connected to a hydraulic pressure source to control the wheel cylinder pressure, and one of the systems is always in communication with the master cylinder. Thus, when the driver operates the brake pedal during execution of the vehicle behavior control, the brake pressure generated by the driver's operation is supplied to one of the braking systems, and the braking force intended by the driver is intended. Can be generated. In this way, by controlling only one system, the braking pressure intended by the driver can be generated.

In other words, if both systems are configured to execute control, if a driver performs a brake operation during control and attempts to generate a brake fluid pressure in accordance with the operation, the driver performs a brake operation. It is necessary to control according to the detection value of the sensor and the detection value thereof, and the configuration becomes expensive. However, in the above-mentioned technology, such a sensor is not necessary, so that the configuration can be made inexpensively. it can.

[0005]

Generally, when performing anti-skid control or vehicle behavior control, it is necessary to calculate the vehicle speed. In calculating the vehicle speed, it is known that a wheel speed sensor and, if necessary, a longitudinal acceleration sensor are further provided to calculate the vehicle speed based on these signals. Using only a wheel speed sensor without using a longitudinal acceleration sensor, applying a predetermined limit to a wheel speed having the highest value (referred to as a select high) among the output values from the respective wheel speed sensors, and using the wheel speed as a vehicle body speed It has been known.

In the above prior art, during vehicle behavior control, the hydraulic pressure of one of the two wheels of the control system is set to zero. That is, in the prior art, even if the brake fluid pressure is generated for one system by the vehicle behavior control and the brake fluid pressure is generated for the other system by the driver's braking operation, Only one wheel is rotated at the same speed as the vehicle speed without generating brake fluid pressure, thereby trying to obtain a more accurate vehicle speed by select high.

However, as a result of the research by the present inventors,
When the driver performs the side brake operation separately from the brake pedal operation during the control by the above-described device, there is a possibility that the wheels whose hydraulic pressure is set to zero in order to obtain the above-mentioned vehicle speed may be locked or locked. However, in this case, a new problem to be solved has been found that the vehicle speed may not be accurately calculated.

SUMMARY OF THE INVENTION An object of the present invention is to solve this new problem. Even when a driver operates a side brake separately from a brake pedal operation during vehicle behavior control, the vehicle speed can be accurately determined. It is intended to be able to calculate.

[0009]

In order to achieve the above-mentioned object, the present invention provides a brake operation hydraulic pressure source a for generating a brake pressure corresponding to a driver's brake operation, as shown in FIG. The brake pipe c to be supplied to the wheel cylinders b of each wheel has two brake pipe lines: a pipe connecting the right front wheel and the left rear wheel, and a pipe connecting the left front wheel and the right rear wheel. A control hydraulic pressure source e configured to be capable of independently supplying a hydraulic pressure to the wheel cylinder b via the two-system brake pipe c; and the wheel cylinder b
The brake hydraulic pressure source to the brake operating hydraulic pressure source a.
Switching means f for switching between the control and the control hydraulic pressure source e, a hydraulic pressure control means g for controlling the hydraulic pressure of the wheel cylinder b, and a vehicle speed based on the wheel speed detected by the wheel speed sensor h. A vehicle behavior detecting means k for calculating a vehicle speed, a vehicle behavior detecting means k for detecting the behavior of the vehicle, and one of the brake pipes c provided by the switching means f based on an input from the vehicle behavior detecting means k. Is connected to the control hydraulic pressure source e, the other brake pipe c is connected to the brake operating hydraulic pressure source a, and the wheel cylinder b disposed on the brake pipe connected to the control hydraulic pressure source e Control means m for executing vehicle behavior control for controlling vehicle behavior by controlling one of the hydraulic pressures by the hydraulic pressure control means g. Switching hand f, the wheel speed of the non-controlled wheel connected to the control hydraulic pressure source e, and the wheel speed of the system connected to the brake operating hydraulic pressure source a on the same side as the non-controlled wheel. And calculating the vehicle speed based on the select high wheel speed which is the higher wheel speed.

[0010] As in the second aspect of the present invention, in the first aspect of the present invention, the vehicle speed calculating means j includes:
At the time of vehicle behavior control, the vehicle body is determined based on the lower value of the select high wheel speed and the pseudo vehicle speed formed by adding a predetermined limit to the highest wheel speed among the four wheel speeds. It is preferable that the speed is calculated.

According to a third aspect of the present invention, in the first or second aspect of the invention, when the vehicle behavior control is not executed, the vehicle speed calculating means j determines the vehicle speed of the four wheels. Preferably, the vehicle speed is calculated based on a value obtained by adding a predetermined limit to the highest speed.

[0012]

According to the present invention, when the vehicle behavior control is executed, the hydraulic pressure of the control hydraulic pressure source is supplied to one of the two brake pipes of the X pipe, and the two-wheel wheel of this system is supplied. A braking force is generated by controlling a wheel cylinder pressure of one of the cylinders, and a vehicle behavior is optimally controlled by a yaw moment generated by the braking force.

At this time, when the driver operates the side brake, the wheel speeds of the rear wheels of the control system and the non-control system decrease, and the rear wheels may tend to lock or lock. .

Here, the vehicle speed calculation means j determines the wheel speed of the non-control wheels connected to the brake pipe c of the control system or the like.
The vehicle speed is calculated based on the higher wheel speed by comparing the uncontrolled wheel with the wheel speed of the system connected to the brake operation hydraulic pressure source a on the same left and right side. For this reason, when the rear wheel is locked or locked by the operation of the side brake as described above and this wheel speed is reduced, the calculation of the vehicle body speed includes the wheel speed of the locked rear wheel. Is not used, and the wheel speed of the front wheel of the non-control system is used. Therefore, highly accurate calculation of the vehicle speed is possible. As described above, it is possible that the driver performs the side brake operation during the vehicle behavior control and simultaneously performs the normal foot brake operation at the same time. In this case, the wheel speed of the non-control system may be reduced. It is thought that it tends to lock,
In the present invention, since the body speed is obtained from the select high wheel speed which is the higher value of the front and rear wheels on the same left and right sides, that is, the wheel speed having the weaker locking tendency, the detection accuracy of the wheel speed is lower than before. I will not do it.

Further, when the vehicle runs on a low μ road, there is a high possibility that the drive wheels generate wheel spin due to the accelerator ON. If the vehicle speed is calculated based on the highest wheel speed among the wheel speeds including the wheel spin value, a value higher than the actual vehicle speed is calculated. On the other hand, according to the second aspect of the present invention, the lower one of the pseudo vehicle body speed formed by adding a predetermined limit to the wheel speeds of the four wheels and the select high wheel speed of the first aspect of the invention. Is used in the calculation of the vehicle speed, even if a wheel spin occurs, the wheel spin component is not included in the calculation of the vehicle speed, and the vehicle speed can be calculated with higher accuracy.

According to the third aspect of the present invention, when the vehicle behavior control is not executed, the wheel speed is calculated based on a value obtained by restricting the highest value among the four wheel speeds.
Even if a wheel spin occurs, the vehicle speed is not calculated based on a value exceeding the value with the restriction, so that the vehicle speed can be accurately calculated even when the vehicle behavior control is not executed.

[0017]

Embodiments of the present invention will be described with reference to the drawings. First, FIG. 2 is a configuration diagram showing an embodiment of the present invention. In the figure, reference numerals 1 to 4 denote wheel speed sensors for detecting the rotation speed of the wheels, each of which outputs a frequency signal corresponding to the rotation speed of the wheel using, for example, a pickup coil.

Reference numeral 5 denotes a steering angle sensor (vehicle behavior detecting means) for detecting a steering angle of the steering wheel. For example, a frequency signal corresponding to the steering angular velocity is output by a phototransistor or the like, and this signal is integrated to process the steering angle. Perform detection.

Reference numeral 6 denotes a yaw speed sensor (vehicle behavior detecting means).
Then, for example, a yaw speed is detected by receiving a Coriolis force from a tuning fork type strain gauge or the like.

Reference numeral 7 denotes a lateral acceleration (hereinafter referred to as lateral G) sensor (vehicle behavior detecting means), which detects lateral acceleration by receiving a lateral force with a cantilever type strain gauge or the like.

Reference numeral 8 denotes a vehicle behavior control device (control means) which reads the vehicle behavior state based on signals from the sensors 1 to 7 and controls the operation of the valves 13a to 13h of the brake hydraulic control actuator 13. In this way, switching of a hydraulic supply source, which will be described later, to the wheel cylinder 20 of each wheel and control of the brake fluid pressure supplied to each wheel cylinder 20 are performed to control the braking force of each wheel. Similarly, it calculates the required engine torque based on the signals from the sensors 1 to 7 and transmits the required engine torque to the engine control device 9.

The brake hydraulic control actuator 13
Is for supplying brake fluid pressure to the wheel cylinders 20 of each wheel and controlling the brake fluid pressure, and is provided in the middle of the brake pipes 21, 22, 23. That is, the brake pipes 21 to 23 are connected to the brake pipes 21 that connect the wheel cylinders 20 of the right front wheel and the left rear wheel.
And a brake pipe 22 connecting the wheel cylinders 20, 20 for the left front wheel and the right rear wheel, a master cylinder 14 for generating a brake operating fluid pressure in response to the driver's pedal operation, and pipes 21, 22. And a brake pipe 23. And the brake hydraulic control actuator 1
3 are hydraulic control valves (hydraulic pressure control means) 13a to 13 which are provided in the middle of the brake pipes 21 and 22 and control the brake hydraulic pressure supplied to each wheel cylinder 20.
and a control hydraulic power source 13i such as a hydraulic pump, which can arbitrarily increase the pressure in response to a signal from the vehicle behavior control device 8 and d.
And a brake pipe 24 connecting the control hydraulic power source 13i and the brake pipe 23, and a brake operation which is provided in the middle of the brake pipes 23, 24 and generates a supply pressure to the brake pipe 21 by the master cylinder 14. A shutoff valve (switching means) 13e and a shutoff valve (switching means) 13e for switching between the hydraulic pressure and the hydraulic pressure of the control hydraulic power source 13i, and a shutoff valve for performing the same switching for the brake pipe 22. (Switching means) 13f and a shutoff valve (switching means) 13h,
In accordance with a signal from the vehicle behavior control device 8, control for switching the pressure supply source to the wheel cylinder 20 singly and for each wheel cylinder 20 is performed independently. In addition, each shut-off valve 13e, 13f, 13
g and 13h are normally the shut-off valves 13 on the master cylinder 14 side so that the brake operation fluid pressure generated in the master cylinder 14 is transmitted to the brake pipes 21 and 22.
g and 13h are opened, and shutoff valves 13e and 13f on the hydraulic supply pump 13i side are closed.

With the configuration described above, various sensors 1 to
7 to detect the behavior of the vehicle, change the brake fluid pressure of each wheel cylinder 20, and apply a yaw moment to the left or right front wheel to suppress yaw moment when the vehicle is in an excessive oversteer state. The vehicle behavior control for generating the braking force is executed.

Next, the control operation of the vehicle behavior control device 8 will be described with reference to the flowcharts of FIGS. The part shown in FIG. 3 is a part that processes a signal indicating the vehicle behavior detected by various sensors.
The wheel speed Vw of each wheel is calculated based on the input from each wheel speed sensor 1-4. In steps 202 to 203, the yaw speed YAW and the lateral GYG are calculated based on the inputs from the yaw speed sensor 6 and the lateral G sensor 7. next,
In step 204, the vehicle body slip angle BETA is calculated. In this calculation, in this embodiment, the calculation is performed using the equation BETA = ∫ (1 / Vi · YG + YAW). Next, in step 205, the vehicle speed Vi is calculated from the calculated values from the wheel speeds Vw calculated in step 201. This calculation method will be described later. In step 206, the slip ratios SLIPFR, SLIPFL, SIP for each wheel are calculated based on the following equation (1).
Find LIPRR and SLIPRL.

SLIPxx = (Vwxx−Vixx) / Vixx (1) where xx in equation (1) indicates each wheel FR, FL, RR, and RL. next,
In step 207, the steering angle is calculated based on the input from the steering angle sensor 5. In step 208, the yaw speed target value YAWS and the vehicle body slip angle target value BETAS stored in the vehicle behavior control device 8 in advance are referred to based on the steering angle and the vehicle speed Vi. In step 209, the difference between the yaw speed target value YAWS and the yaw speed YAW calculated in step 202, and the vehicle body slip angle target value BETA and the vehicle body slip angle B calculated in step 204.
A value obtained by constantly adding predetermined weighting constants K1 and K2 to the difference from ETA is calculated as an index KFT for correcting vehicle behavior.

Next, proceeding to FIG. 5, in step 210,
The index KFT is converted into a tire generated braking force required value QFxx. In this step, TF and TR are の of the tread length of the vehicle, and the moment is force × length. Therefore, the braking force can be obtained by the equation shown in this step.

Next, at step 211, the slip ratio target value SLIPSxx is calculated by the following formula: SLIPSxx = QFxx × Slim / (Wx · μ). The braking force depends on the wheel load × μ × slip ratio, and the slip ratio that generates the maximum braking force is Slim, and the slip ratio is normalized (the maximum braking force generation slip =
When the slip ratio is replaced so as to be 1), QF = μ · W · (SLIP / Slim) However, −1 <(SLIP / Slim) <1. Thereby, the slip ratio target value SLIPxx can be calculated.

Next, in step 212, it is determined whether or not the current slip ratio target value SLIP (n) is negative (= the presence or absence of a braking request). , The target hydraulic pressure PBN, the current target slip ratio SLIPS (n) and the current slip ratio S
It is calculated by PID control using LIP (n).

For the wheels for which no braking request has been issued, the process proceeds from step 213 to step 214, where the target hydraulic pressure PBN is reset to zero.

Next, the routine proceeds to step 215, where the pressure increase / decrease amount △ PBN is calculated from the difference between the previously calculated target hydraulic pressure PBN (n) -1 and the currently calculated target hydraulic pressure PBN (n). In step 216, increase / decrease hydraulic pressure → increase / decrease pulse conversion gain KINC, KD with respect to increase / decrease amount 減 圧 PBN
The pulse times INCN and DECN for energizing the hydraulic control valves 13a to 13d are calculated by multiplying the EC, and the pulse energization corresponding to this value is performed. The wheel cylinder pressure is controlled according to the procedure described above, and the yaw moment of the vehicle is optimally controlled.

Next, the procedure for calculating the vehicle speed executed in step 205 will be described in detail with reference to FIG. First, in step 205a, the steering angle is calculated, and then in step 205
In step b, the lateral acceleration is calculated.
At 5c, the yaw rate is calculated.

Here, first, in step 205d, the first vehicle speed VI_1 is obtained. This first vehicle speed VI
_1 is the select high value max (VWF
R, VWFL, VWRR, VWRL) and the speed at which the vehicle accelerates at the maximum (that is, 1 of the first vehicle speed VI_1).
This is a value obtained by adding 2 km / h to the value before 0 ms, and is approximately 5.6.
G value) and the smaller value is selected. The first vehicle speed VI_1 corresponds to “a value obtained by adding a predetermined limit to the highest speed among the four wheel speeds” according to the third aspect of the present invention.

At step 205e, a posture control judgment is executed. This attitude control determination is a determination as to whether or not the vehicle is in an excessive oversteer state and needs to be controlled to suppress this state.
In this embodiment, it is assumed that the control flag is switched to ON when the determination is YES.

If it is determined in step 205e that the posture control is necessary, the process proceeds to step 205f, where it is determined whether or not the vehicle is turning right. Sometimes step 205
Proceed to h.

In step 205g, which proceeds during a right turn, it is determined whether the wheel speed VWFR of the right front wheel is equal to or higher than the wheel speed VWRR of the right rear wheel. If the wheel speed of the right front wheel is higher, the process proceeds to step 205g. Proceeding to 205j, the right front wheel speed VWF
Based on R, this value is added to the tread TRED and the yaw change rate d
The second vehicle speed VI_2 is calculated by adding a correction multiplied by ψ. On the other hand, when the wheel speed of the right rear wheel is higher, the second vehicle body speed VI_2 is calculated by adding the same correction to the wheel speed VWRR of the right rear wheel as described above.

Step 205h, which proceeds when turning left,
Similarly to the above, the second vehicle speed VI_2 is calculated based on the higher one of the left and right front wheel speeds VWFL and VWRL. That is, the processing of 205g to 205n corresponds to the processing of the "calculating the vehicle body speed based on the select high wheel speed" part of the invention of claim 1.

Next, the routine proceeds to step 205p, where the lower one of the first vehicle speed VI_1 and the second vehicle speed VI_2 is selected to form the final vehicle speed VI_3. This final vehicle speed VI_3 is used as the vehicle speed in the processing after step 206 shown in FIGS. This step 205
The processing of p corresponds to the processing of the "calculating the vehicle speed based on the lower value of the select high wheel speed and the pseudo vehicle speed" of the second aspect of the invention.

Next, an operation example of the embodiment will be described with reference to the drawings. In this description, an operation example during a right turn will be described. First, FIG. 6 illustrates an example of a case where the vehicle behavior control is executed in a state where the side brake is operated during a right turn and no wheel spin occurs in the drive wheel (rear wheel).

As shown in this figure, when the side brake is operated during turning, the wheel speed VWR of the rear wheel is increased as shown in the figure.
R and VWRL decrease. At this time, when the vehicle behavior control execution flag is not set (OFF), the flow proceeds from step 205d to 205e to 205p,
The vehicle body speed VI_2 is not formed, and the final vehicle body speed VI_3 = V
Processed as I_1. In this case, the vehicle speed is formed based on either the highest wheel speed among the four wheels or a value obtained by limiting the maximum value that can be accelerated, and wheel spin of the drive wheel occurs. If there is no such wheel, the wheel speed is formed based on one of the left wheel speeds VWFL and VWRL, which is the turning outer wheel.

Next, when the vehicle is excessively oversteered, the wheel cylinder 2 of the left front wheel is used to suppress this.
At 0, a braking force is generated to generate a counterclockwise yaw rate in the vehicle, thereby stabilizing the posture of the vehicle. In this case, the control hydraulic pressure source 13i is connected to the brake pipe 22, and the hydraulic pressure control is performed only on the left front wheel. Further, the brake pipe 21 of the other system is connected to the master cylinder 1.
4 is maintained so that when the driver performs a braking operation, a braking force corresponding to the operation is generated in the wheel cylinder 20 connected to the brake pipe 21 of this system.

When the vehicle behavior control execution flag is set (ON) when the vehicle behavior control is executed as described above, the right rear wheel diagonally opposite to the control wheel in the technique described in the prior art. The vehicle speed is formed based on the wheel speed VWRR of the vehicle. On the other hand, in the present embodiment, first, a flow of steps 205e → 205f → 205g is performed, and the second vehicle speed is determined based on the higher one of the wheel speeds VWFR and VERR of the front and rear wheels on the right side of the vehicle. VI_2 is formed, and the lower one of the second vehicle body speed VI_2 and the first vehicle body speed VI_1 is processed as the final vehicle body speed VI_3.

Therefore, by operating the side brake, the wheel speeds VWRR, VWRL of the left and right rear wheels are changed as shown in the figure.
Is decreased, the right front wheel speed VWFR is selected as the second vehicle body speed VI_2. The right front wheel is connected to the brake pipe 21 of the non-control system, and has a lower numerical value due to the difference between the inner and outer turning wheels. Therefore, this value is selected as the basis of the vehicle body speed. As described above, in the present embodiment, since the vehicle speed is not formed by the wheel speed of the rear wheel locked by the side brake, the calculation accuracy of the vehicle speed is improved and the control accuracy is improved as compared with the related art. be able to.

Next, FIG. 7 shows a case where the vehicle behavior control is executed during a right turn, when the side brake is not operated, and wheel spin occurs in the drive wheel (rear wheel). An example is shown.

As shown in this figure, the accelerator opening increases and wheel spin occurs on the rear wheel, and the wheel speed VWR of the rear wheel is increased.
When R and VWRL increase, first, step 205d
The first body speed VI_1 formed at the time is a value (VI_1) obtained by giving a predetermined limit to the previous first body speed VI_1.
1.10 ms before +2 km / h).
Thereafter, when the vehicle behavior control is executed, a second vehicle body speed VI_2 according to the turning direction is formed. In this example, since the drive wheel slip occurs at the rear wheel, the second vehicle body speed VI_2 is formed based on the wheel speed VWRR of the right rear wheel. Then, in the subsequent step 205p, since the lower value of the first vehicle speed VI_1 and the second vehicle speed VI_2 is selected, the value (VI_1) obtained by giving a predetermined limit to the previous first vehicle speed VI_1 .10 ms before +2 km / h) is selected.

As described above, even if the driving wheel slip occurs and the wheel speeds VWRR and VWRL of the driving wheels become higher than the actual vehicle speed, the vehicle speed is limited to the maximum value at which the vehicle can be accelerated. Does not increase the estimation error. That is, as described above, in order to increase the accuracy at the time of operating the side brake, the second vehicle body speed VI_2, which is the select high of the front and rear wheels on the turning inner wheel side, is configured to be formed. When it occurs, the second vehicle speed VI
_2, the wheel speed of this wheel spin wheel is selected. In step 205p, the first vehicle speed V
Since the configuration is such that the select low between I_1 and the second vehicle speed VI_2 is performed, the vehicle speed does not become larger than the value given the predetermined limit, and the error does not increase.

Although the embodiment has been described with reference to the drawings, the configuration of the present invention is not limited to the configuration of this embodiment. For example, although the master cylinder is shown as a brake operation hydraulic pressure source, it is only necessary that any means that generates hydraulic pressure according to the braking operation of the driver be used. However, the present invention is not limited to this, and means for electrically detecting the braking operation of the driver and generating a hydraulic pressure according to the detected value may be used.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing the present invention.

FIG. 2 is an overall view showing an embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of vehicle behavior control according to the embodiment.

FIG. 4 is a flowchart showing a flow of vehicle behavior control according to the embodiment.

FIG. 5 is a flowchart showing a flow of a vehicle body speed calculation according to the embodiment.

FIG. 6 is a time chart showing an operation example of the embodiment.

FIG. 7 is a time chart showing an operation example of the embodiment.

[Explanation of symbols]

 a Brake operation hydraulic pressure source b Wheel cylinder c Brake pipe d Brake device e Control hydraulic pressure source f Switching means g Hydraulic pressure control means h Wheel speed sensor j Vehicle speed calculation means k Vehicle behavior detection means m Control means 1-4 wheels Speed sensor 5 Steering angle sensor 6 Yaw speed sensor 7 Lateral acceleration sensor 8 Vehicle behavior control device 13a-d Hydraulic control valve 13e-h Shutoff valve 13i Hydraulic supply pump 14 Master cylinder 20 Wheel cylinder 21 Brake pipe 22 Brake pipe 23 Brake pipe 24 Brake piping

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D045 BB40 CC03 EE21 FF42 GG27 GG28 3D046 BB21 CC02 DD04 EE01 FF09 HH03 HH23 HH36 JJ06 KK03 LL05 LL23 LL36

Claims (3)

[Claims] 1. A brake pipe connecting a right front wheel and a left rear wheel as a brake pipe for supplying a brake operation hydraulic pressure source that generates a brake pressure according to a driver's brake operation to a wheel cylinder of each wheel; A brake device having two systems of brake pipes, a pipe connecting the left front wheel and the right rear wheel, and a control device configured to be able to independently supply hydraulic pressure to the wheel cylinder via the two systems of brake pipes A hydraulic pressure source; switching means for switching between a brake hydraulic pressure supply source to the wheel cylinder as the brake operating hydraulic pressure source and the control hydraulic pressure source; and controlling a hydraulic pressure of the wheel cylinder. A vehicle pressure calculating means for calculating a vehicle body speed based on a wheel speed detected by a wheel speed sensor; a vehicle behavior detecting means for detecting a vehicle behavior; Entering Based on the above, the switching means connects one brake pipe to the control hydraulic pressure source and connects the other brake pipe to a brake operating hydraulic pressure source, and connects the brake pipe to the control hydraulic pressure source. Control means for performing vehicle behavior control for controlling the behavior of the vehicle by controlling the hydraulic pressure of one of the wheel cylinders disposed on the vehicle by the hydraulic pressure control means. The means comprises, when the vehicle behavior control is executed, a wheel speed of a non-controlled wheel of a system connected to the control hydraulic pressure source by the switching means, and a brake operation hydraulic pressure source on the same left and right side as the non-controlled wheel. A vehicle behavior control device configured to compare a wheel speed of a system connected to the vehicle speed and calculate a vehicle body speed based on a select high wheel speed which is a higher wheel speed. 2. The vehicle speed calculating means according to claim 1, wherein said vehicle speed calculating means calculates a selected high wheel speed and a pseudo vehicle speed formed by adding a predetermined limit to a highest wheel speed among four wheel speeds during vehicle behavior control. The vehicle behavior control device according to claim 1, wherein the vehicle speed is calculated based on the lower value. 3. The vehicle speed calculating means is configured to calculate the vehicle speed based on a value obtained by adding a predetermined limit to the highest one of the four wheel speeds when the vehicle behavior control is not executed. The vehicle behavior control device according to claim 1 or 2, wherein: