JPH04243654A - Brake force control device for vehicle - Google Patents

Abstract

PURPOSE:To prevent the slip-off of brake force caused by the simultaneous independent operation of vehicle behavior control and slip control (ABS control) at the time of braking in the high lateral acceleration (high lateral G) state. CONSTITUTION:The controller of a brake force control system computes (S102, S103) the brake fluid pressure difference DELTAP1 of lateral wheels in vehicle bahavior control and the pressure reducing quantity DELTAP2i of brake fluid pressure of each wheel by ABS control. At the time corresponding to the operation time of the former control, DELTAP2i value on the pressure reducing quantity DELTAP2i in the latter control is corrected (S104, S105) by a coefficient K corresponding to lateral G. The coefficient K is set to be smaller as the lateral G is larger. With this correction, the controller gives priority to vehicle behavior control at the time of braking in the high lateral G state.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a braking force control device for a vehicle, and more particularly to a braking force control device that controls vehicle behavior by generating a difference in braking force between left and right wheels of a vehicle, and controls the amount of wheel slip. The present invention relates to a braking force control device capable of controlling braking force.

0002

2. Description of the Related Art As a device for controlling the braking force of a vehicle, the present applicant has already proposed a braking force control device that attempts to control vehicle behavior by making a difference between the braking forces of the left and right wheels of the vehicle ( (Patent Application No. 1-250645, etc.). A braking control system that generates such a braking force difference can actively utilize the braking force difference (brake fluid pressure difference) to improve the turning ability of the vehicle during turning braking or to improve stability. It is. In particular, the patent application No. 1-250645 uses a yaw rate feedback method to control hydraulic pressure by controlling left and right brake hydraulic pressures differently to eliminate the deviation between the actual yaw rate of the vehicle and the target yaw rate. This contributes to improved steering stability during braking.

0003

[Problems to be Solved by the Invention] On the other hand, there is an anti-skid system (ABS), which aims to prevent wheel locking, as a braking force control system. be effective. However, if you want to configure a system that has both control functions, such as adding the above vehicle behavior control to a vehicle equipped with an anti-skid system, or newly incorporating both controls into the brake control system, it is necessary to simply combine them. In this case, the braking force may be reduced during braking. Considering the case where braking is performed in a state of high lateral acceleration, the wheel load on the inner wheel side in the turning direction decreases. Therefore, low μ
Even if the vehicle is not on a road, slip control is activated when the wheel load decreases, reducing brake fluid pressure. In this way, the inner wheel side is depressurized, and on the other hand, the vehicle behavior control side, which controls the hydraulic pressure so that the vehicle behavior has the target characteristics by the left and right brake fluid pressure difference, tries to cancel the braking understeer toward the outer wheel side in the turning direction. When the control is activated, the brake fluid pressure is reduced, resulting in a reduction in braking force. In particular, when the hydraulic pressure of the inner wheel is low and the hydraulic pressure of the outer wheel is lowered to generate the required left and right hydraulic pressure difference, the amount of decrease will be large, and the braking force during braking will be reduced by that amount. The decline will be significant. However, under high lateral acceleration conditions,
During braking, when running at a deceleration where the deceleration is not relatively large (for example, at a medium deceleration of about 0.3g to 0.6g),
There is a tendency for the vehicle to behave as if it turns inward in the direction of the turn (spin tendency), and may turn more than the driver's steering amount (also, the vehicle may drift outward in the direction of the turn at high decelerations). In some cases, the vehicle behavior may change significantly), so it is advantageous to maintain behavior control to ensure vehicle stability.

An object of the present invention is to enable vehicle behavior control and slip control while preventing a reduction in braking force when braking is performed in a state of high lateral acceleration and both controls are activated simultaneously. An object of the present invention is to provide a braking force control device for a vehicle that can ensure the stability of the vehicle.

[0005]

[Means for Solving the Problems] For this purpose, the braking force control device of the present invention, as conceptually shown in FIG. A turning state detecting means for detecting a turning state of the vehicle, a slip physical quantity calculating means for calculating a slip physical quantity used in wheel slip amount control, a lateral acceleration detecting means for detecting a lateral acceleration of the vehicle body, and a turning state detecting means for detecting a turning state from the turning state detecting means. Creates a difference in the braking force of the controlled wheels on the left and right sides of the vehicle depending on the output,
The first step is to control the braking force so that the vehicle behavior matches the target characteristics.
and a second braking force control for controlling the braking force so that the wheel slip is within a predetermined range based on the output of the slip physical quantity calculating means, and the lateral acceleration detecting means braking force control means including a priority control means for giving priority to the first braking force control when the detected lateral acceleration is greater than a predetermined value based on the output from the brake control means.

[0006]

[Operation] The braking force control means generates a difference between the left and right braking forces of the wheels to be controlled in accordance with the output from the turning state detection means that detects the turning state, and adjusts the braking force so that the vehicle behavior becomes the target characteristic. A first braking force control is performed to control the braking force, and a second braking force control is performed to control the braking force to keep the vehicle slip within a predetermined range based on the output from the slip physical quantity calculating means. Based on the output, the priority control means preferentially performs the first braking force control when the lateral acceleration becomes larger than a predetermined value. As a result, it is possible to avoid a decrease in braking force due to both controls operating independently and simultaneously during braking during high lateral acceleration driving where the lateral acceleration exceeds a predetermined value. This makes it possible to achieve effective vehicle behavior control, which is braking force control.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 shows the configuration of an embodiment of the braking force control device of the present invention. The applicable vehicle is equipped with means that can independently control the left and right braking forces of the front and/or rear wheels, and in this example, the braking force of each front and rear wheel can be controlled individually. . In the diagram, 1L and 1R are the left and right front wheels, 2L
, 2R indicates the left and right rear wheels, 3 indicates the brake pedal, and 4 indicates the tandem master cylinder (M/C). each wheel 1
L, 1R, 2L, 2R are wheel cylinders (W
/C) 5L, 5R, 6L, 6R, and when these wheel cylinders are supplied with hydraulic pressure from the master cylinder 4, each wheel is braked individually.

[0008] Here, to explain the brake fluid pressure (braking fluid pressure) system of the braking device, the front wheel brake system 7F from the master cylinder 4 has pipes 8F, 9F, 10F and fluid pressure control valves 11F, 12F. In the illustrated example, the rear brake system 7R is connected to the left and right rear wheel cylinders 6L via pipes 8R, 9R, 10R and hydraulic pressure control valves 11R, 12R.
, shall lead to 6R. The rear brake system is
When restricting the increase in rear wheel brake fluid pressure in order to prevent early rear wheel locking during braking, a fluid pressure control valve can be included as an adjustment means for this purpose. Hydraulic pressure control valve 11F, 1
2F, 11R, and 12R are used for anti-skid and vehicle behavior control by individually controlling the brake fluid pressure directed to the wheel cylinders 5L, 5R, 6L, and 6R of the corresponding wheels. In the pressure position, the brake fluid pressure is increased toward the source pressure, and the first stage is turned on.
When the brake fluid pressure is not increased or decreased, it becomes a pressure holding position, and the second stage O
In the N state, the brake fluid pressure is partially released to the reservoirs 13F and 13R (reservoir tank) and is reduced to a depressurizing position. For example, when the control valve driving currents I1 to I4 are 0A, the pressure increase position is set, when the currents I1 to I4 are 2A, the pressure holding position is set, and when the currents I1 to I4 are 5A, the pressure reduction position is set. The brake fluid in the reservoirs 13F and 13R is returned to the pipes 8F and 8R by the pumps 14F and 14R, which are driven during the above-mentioned pressure maintenance and pressure reduction, and is returned to the accumulators 15F and 15R of these pipes for reuse. . Hydraulic pressure control valve 11F, 12F, 11R,
12R is ON/OFF controlled by a controller 16, and this controller 16 includes a steering angle sensor 17 that detects the steering angle θ of the steering wheel (steering wheel).
signal from the brake switch 18 that turns on when the brake pedal 3 is depressed, wheels 1L, 1R, 2
Signals from wheel speed sensors 19 to 22 that detect rotational peripheral speeds (wheel speeds) VW1 to VW4 of L and 2R, and a longitudinal acceleration sensor (longitudinal G sensor) 23 that detects longitudinal acceleration of the vehicle body.
, and signals from a lateral acceleration sensor (lateral G sensor) 24 that detects lateral acceleration. Signals from the wheel speed sensors are used for anti-skid control performed by the controller 16 as well as traction control. For traction control, a control signal to the engine power regulator shall be sent.

The controller 16 also has hydraulic pressure P1 of the wheel cylinders 5L, 5R, 6L, 6R of each wheel.
~Hydraulic pressure sensors 25L, 25R, 26 that detect P4
Hydraulic pressure sensors 271 and 272 receive signals from L and 26R and detect the hydraulic pressure PM of the master cylinder 4 (front wheel hydraulic pressure PM1, rear wheel hydraulic pressure PM2).
A signal is input from Regarding master cylinder hydraulic pressure detection, for example, only the front wheel system may be detected and represented. The output of the fluid pressure sensor is a signal used to control brake fluid pressure by setting a target value for wheel cylinder fluid pressure and operating the fluid pressure control valve so that the actual wheel cylinder fluid pressure matches the target value. used as.

In anti-skid control, in the 4-channel, 4-sensor system as in this example, a wheel speed detection value, a vehicle body speed detection value, and a slip amount detection value are obtained for each wheel, and the detected wheel speed is and the detected vehicle speed to control the braking force so that the slip of the relevant wheel is below the set value,
As a result, the left front wheel, right front wheel, left rear wheel, and right rear wheel are individually anti-skid controlled to achieve maximum braking efficiency for each wheel, thereby avoiding wheel lock.

The controller 16 includes a microcomputer that uses an input detection circuit, an arithmetic processing circuit, a memory circuit, an output circuit, etc., and controls the vehicle by creating a difference in braking force on the left and right sides of the vehicle depending on the turning state. When performing behavior control, that is, when controlling the braking force so that the vehicle behavior when turning has the target characteristics, based on predetermined input information and according to the control program described later, Calculate the brake fluid pressure difference between the inner and outer wheels), use this to calculate the target wheel cylinder fluid pressure value as the braking force control value for each wheel, and send the corresponding signal as the control valve drive current. do. The controller 16 also
When performing slip amount control using a skid cycle, calculate the wheel slip rate, calculate the target wheel cylinder fluid pressure value based on it, and also calculate the pressure reduction amount at that time (
The hydraulic pressure difference (with respect to the master cylinder hydraulic pressure) is also calculated as a controlled variable. Even when such anti-skid control is performed independently, as in the case where the vehicle behavior control described above is performed independently, a signal corresponding to the target wheel cylinder hydraulic pressure value due to anti-skid control is sent out as a control valve drive current, and each Controls wheel brake fluid pressure.

Furthermore, the controller 16 is configured to perform vehicle behavior control preferentially under certain conditions in a control region where the vehicle behavior control and anti-skid control operate simultaneously. That is, in a high lateral acceleration state where the output from the lateral acceleration sensor 24 is greater than a predetermined set value, processing is also executed to give priority to vehicle behavior control,
The controller 16 also constitutes such priority control means.

FIG. 3 shows an example of a braking force control program including braking force modification processing for the above-mentioned priority control in a region where vehicle behavior control and anti-skid control are performed simultaneously. It is a flowchart which shows. This program is executed within the controller 16 at regular intervals.

First, in step S101, the steering angle θ, deceleration Xg, lateral acceleration Yg, etc. are read from the signals of the steering angle sensor 17, longitudinal G sensor 23, and lateral G sensor 24 as control parameters. In the next step S102, brake fluid for the left and right wheels is applied in accordance with the turning state to control the braking force so that the vehicle behavior during turning has the target characteristics by creating a difference between the left and right braking forces depending on the turning state. Pressure difference ΔP1
Execute the calculation process. Here, the required yaw rate (
The brake fluid pressure difference value ΔP1 for generating the yaw moment is calculated according to the steering angle θ and the deceleration Xg, that is, ΔP1=f(θ, Xg). In addition, the method of determining the brake fluid pressure difference P1 in this case is, for example, as described in Japanese Patent Application No. 2-40975 filed earlier by the present applicant. The ΔP1 value may be determined by determining the hydraulic pressure difference and further correcting it according to the deceleration, or the method described in the above-mentioned application (Japanese Patent Application No. 1-250645) may be used. The ΔP1 value to be obtained in step S102 may be determined by using a brake fluid pressure difference applied in the target brake fluid pressure calculation process in hydraulic pressure control using the yaw rate feedback method. This braking force control can be applied to both vehicle behavior control, whether it is a yaw rate feedback method or a control mode that does not use yaw rate feedback.

Next, in step S103, the amount of pressure reduction ΔP2i (i=
1 to 4) are performed. The processing here may follow a normal known calculation method for ABS control, and may have the following content. That is,
The wheel speeds VW1 to VW4 of each wheel are measured by wheel speed sensors 19 to 2.
Read from the signal No. 2 and calculate the amount of wheel slip. To calculate the slip amount of each wheel, specifically, the vehicle speed is calculated using the method used in normal anti-skid control using the wheel speed, and the slip amount of each wheel is calculated using the vehicle speed value and the above wheel speed. This can be done by obtaining the rate. In this way, the slip amount of each wheel is calculated and the target hydraulic pressure PABS is calculated.
(S) i (i=1 to 4), that is, the target wheel cylinder hydraulic pressure value for each wheel determined by anti-skid control is determined, and the pressure reduction amount ΔP2i is calculated. Here, this step S1
As the final calculated value to be obtained in 03, the amount of pressure reduction Δ for each wheel is
P2i, that is, the pressure reduction amount determined by the anti-skid control, is used to weight this according to the lateral acceleration Yg, which will be described later, and ΔP2i is the target hydraulic pressure P.
ABS (S) i and current hydraulic pressure Pi (i=1~4
), it is assumed that ΔP2i=PABS (S) i - Pi.

[0016] In the following step S104, in the case of this program example, it is determined whether or not it is the timing for the vehicle behavior control to operate, using the calculated value ΔP1 in the step S102, and if the answer is YES, step S1 is executed.
05 and directly proceeds to step S106 and below, while if the answer is NO, the process proceeds to step S1 after weighting the ΔP2i value in step S105 according to the lateral acceleration.
Execute 06 and below. In step S106, in this program example, the brake fluid pressure difference ΔP1 in the vehicle behavior control is distributed according to a distribution pattern to be described later, and ΔP1i (i=1 to 4) is determined as a control amount for each wheel in the control. Processing and the following formula ΔPti=
ΔP1i+ΔP2i ...ΔPti (i=
1 to 4), and step S107.
is an output process using the ΔPti value as the final control amount for each wheel obtained in this way. Here, Δ
Pti is obtained by distributing the calculated brake fluid pressure difference ΔP1 in vehicle behavior control when the manner in which the left and right difference in brake fluid pressure is generated in vehicle behavior control is due to unilateral pressure reduction (
In other words, since it is expressed as the sum of the amount of pressure reduction set at each wheel stage and the amount of pressure reduction of each wheel in anti-skid control,
It means the total amount of pressure reduction for each wheel.

[0017] When proceeding directly from step S104 to step S106, ΔP1 = 0 is applied to the processing from step S106 onwards, and ΔP
For the 2i value, the ABS determined in step S103
As a result of applying the calculated value ΔP2i as the control output as is, when anti-skid control is executed, braking force control is performed solely by anti-skid control. That is, in such a case, the vehicle behavior control is inactive, there is no pressure reduction, and ΔP1i=0, so ΔPti
=ΔP2i. Specifically, the left front wheel pressure reduction amount ΔPt1, the right front wheel pressure reduction amount ΔPt2, and the left rear wheel pressure reduction amount Δ
Pt3 and the pressure reduction amount ΔPt4 of the right rear wheel are each finally set as follows. ΔPt1=ΔP11+ΔP21=
0+ΔP21=ΔP21...2
ΔPt2=ΔP12+ΔP22=0+ΔP22=ΔP2
2...3 ΔPt3=ΔP13+
ΔP23=0+ΔP23=ΔP23...4
ΔPt4=ΔP14+ΔP24=0+ΔP2
4=ΔP24...5 Therefore, the braking force control in this case is only anti-skid control, and as in the case of normal 4-channel anti-skid control, a predetermined slip rate is applied to the corresponding wheel where anti-skid control is activated. The braking fluid pressure, that is, the wheel cylinder fluid pressure Pi (i=
1 to 4) are controlled depending on the target value in anti-skid control. Here, hydraulic pressure sensors 25L, 25 are installed on each wheel.
R, 26L, and 26R are provided, so the brake fluid pressure of each wheel is controlled so that master cylinder fluid pressure - wheel cylinder fluid pressure = ΔPti. in particular,
In step S107, target wheel cylinder hydraulic pressure P(
S) i (i=1 to 4), P(S) i
= PM -ΔPti...6, the brake fluid pressure is increased by operating the fluid pressure control valve using the control valve drive current Ii (i = 1 to 4) so that the actual wheel cylinder fluid pressure matches the target value. It's about controlling.

On the other hand, when it is determined in step S104 that the vehicle behavior control is activated, in order to prevent a significant decrease in braking force due to simultaneous activation of the vehicle behavior control and anti-skid control in a state of high lateral acceleration. , and executes a process for giving priority to vehicle behavior control as easily as possible to ensure vehicle stability. That is, in this example,
Proceeding from step S104 to step S105, here, the calculated pressure reduction amount ΔP2i value in step S103 and the weighting coefficient K according to the lateral acceleration Yg are used.
The following formula ΔP2i=ΔP
2i×K . . . 7 is used to reset ΔP2i and apply this to the processing after step S106, and the brake fluid pressure difference ΔP1 in vehicle behavior control is directly applied to the following processing.

FIG. 4 shows an example of the characteristics of the coefficient K used for the above-mentioned weighting.
The value is set to 1.0 in the range up to Ygs, and the value is set to become smaller as the lateral acceleration Yg increases beyond Ygs. In this step S105, the K value corresponding to the detected lateral acceleration Yg is searched in a table and the calculation of the above equation 7 is executed. Thus, when resetting the ΔP2i value by weighting as described above is performed,
In a state of high lateral acceleration exceeding a predetermined value Ygs, the amount of pressure reduction by ABS control is modified to a small value, and as a result, priority is given to vehicle behavior control in a state of high lateral acceleration. Two types of control, behavior control and anti-skid control, work simultaneously to prevent braking force from being lost. In this example, priority is given to vehicle behavior control by suppressing the other control, anti-skid control, as shown in FIG. For example, the control mode may be such that the control is prohibited.

[0020] Furthermore, the above-mentioned priority control of vehicle behavior control can be effective in stabilizing vehicle behavior as described below. Since it can be said that the situation is likely to change significantly,
If vehicle behavior is controlled based on the difference in braking force between the left and right sides in order to suppress undesirable behavior, behavior such as turning the vehicle more than necessary can be appropriately prevented and the vehicle behavior can be stabilized. Therefore, in addition to preventing the braking force from decreasing as described above, it is also possible to easily improve the stability of the vehicle.

After executing step S105, steps S106 and S107 are executed and the program is terminated. In this case, the brake fluid pressure difference ΔP1 is The distribution of ΔP1i for each wheel is determined by
For example, this is performed according to a pattern as shown in FIG. The vehicle behavior control output distribution pattern (distribution method) shown in the figure is based on the 4-channel system, and includes one when anti-skid control is activated (ABS control is activated) and one when anti-skid control is not activated (ABS is not activated). (when activated). When distributing the vehicle behavior control output when the anti-skid is not activated, and therefore when executing the vehicle behavior control alone, the vehicle behavior control output is basically output to the front side. That is, specifically, ΔP1i for each wheel is determined so that the brake fluid pressure difference ΔP1 in step S102 is generated between the left and right front wheels.

FIG. 6 is a conceptual diagram illustrating the mode of distribution during a left turn in such a case. As shown in the figure, in this case, the brake fluid pressure difference ΔP1 is reduced by the amount corresponding to the value ΔP1 on the right front wheel side. It will be assigned as ΔP12. More specifically, in the case of vehicle behavior control alone, ΔP2i on the anti-skid control side has a value of 0, and the distribution pattern is toward the front wheels as shown in FIG. 5, so the braking force on the outside of the turning direction is reduced. When turning left with one-sided decompression, the amount of decompression calculated by the above formula 1 is ΔPt1=0, ΔP
t2=ΔP12 (=ΔP1), ΔPt3=ΔPt4=
It becomes 0. Therefore, the target value in this case is as shown in FIG. 6, and specifically, pressure reduction control is executed only for the right front wheel cylinder fluid pressure (step S10).
7).

Furthermore, in the above, if a shortage occurs (if the necessary hydraulic pressure difference cannot be created between the left and right front wheels alone), this is made to be satisfied on the rear side. Furthermore, in this case, for example, the maximum value that can be decompressed per wheel (for example, the limit is 30 kg/cm2
), and if the control command value for pressure reduction exceeds (for example, ΔP1 = 50 kg/cm2), the other wheels may compensate for the excess. Furthermore, when prioritizing front wheel distribution as described above, even in the case of a brake system in which the rear wheel brake fluid pressure is limited to a lower level than that of the front wheels at a predetermined split point, the braking force of the front wheels is large. Therefore, the degree to which the pressure can be reduced is greater than that for the rear wheels, making it easier to create a difference in braking force.

It is assumed that the distribution when the anti-skid control is activated, that is, the distribution of the vehicle behavior control output in both control execution regions, is performed according to the pattern shown in FIG. 5, and ΔP1i is determined. When ABS is activated on only one wheel, or when ABS is activated on both front and rear wheels, the vehicle behavior can be controlled by creating a difference in braking force between the left and right front wheels or the left and right rear wheels when ABS is not activated. Determine ΔP1i and distribute the shortfall to the ABS activation side. In addition, when two wheels are in operation and the two wheels are diagonal (for example, when ABS is activated on the left front wheel and right rear wheel), between the other diagonally left and right wheels (in the above example, the right front wheel and left rear wheel ΔP1i is determined so as to make a difference in braking force between
Allocate between rings. In this way, the reason why the vehicle behavior control is used to distribute the fluid pressure to create a difference between the left and right wheels of the vehicle when ABS control is not activated is to enable each control to be performed as independently as possible even in both control execution areas. It is based on the concept and is useful for improving control accuracy. That is, ABS
Assuming a case where vehicle behavior control is executed with the left and right working wheels as the operating wheels, the control value in ABS control in that case has a relatively large fluctuation, and therefore it is necessary to further generate the required hydraulic pressure difference between the left and right wheels. Sometimes, the control value of vehicle behavior control is easily affected by the above fluctuations, and therefore the A
BS Compared to using the non-actuating side, accuracy is more affected. Therefore, as mentioned above, if there are left and right wheels in which the ABS is not activated, the distribution will be made targeting those wheels.

[0025] Also, in the case of two-wheel operation, either the left or right
If the wheels are ABS operating wheels, the above method cannot be adopted, so the basic front-priority distribution pattern when ABS is not operating as described above will be used.Furthermore, if three wheels are operating, including the ABS non-operating wheels. ΔP1i is determined so as to create a difference in braking force between the front and rear left and right wheels. Furthermore, even when the four-wheel ABS is activated, the distribution is performed using the same distribution pattern as when the ABS is not activated.

In this way, in a region where both controls operate simultaneously, the brake fluid pressure difference ΔP1 is adjusted using a distribution pattern corresponding to the ABS control operating state as described above.
The amount for each wheel is determined as ΔP1i, and the total pressure reduction amount ΔPti for each wheel is determined by using this and the reset value ΔP2i (=ΔP2i×K) as ΔPti=ΔP1i+ΔP2
The total decompression amount Δ calculated and determined as i
Braking hydraulic pressure control for each wheel is executed using the target wheel cylinder hydraulic pressure set according to Pti as a target value.

With the above control, in this embodiment,
In the case of high lateral acceleration turning braking, even if the slip control timing is such that the anti-skid control is activated on the inner wheel in the turning direction due to a decrease in the wheel load, the timing on the outer wheel in the turning direction is during the turning braking. Even when vehicle behavior control is executed in an attempt to cancel braking understeer, it is possible to avoid the situation where the braking force is drastically reduced when the brake fluid pressure is reduced depending on each control. Not only can stability be ensured, but when control is performed in consideration of the distribution pattern described above, it can also contribute to improving the accuracy of braking force control in a vehicle equipped with both four-channel control systems.

In this embodiment, the case where the braking force of the front, rear, left and right wheels can be controlled independently is explained as an example. In this case, the vehicle behavior control output is always applied to the front wheels, so it is not necessary to use the distribution pattern according to the operating state of the ABS as described above. Furthermore, even in the case of a four-channel system, it is also possible to implement the vehicle behavior control in such a manner that the wheels to be controlled are set in advance to either the left or the right without using such a distribution pattern.

[0029]

[Effects of the Invention] According to the braking force control device of the present invention, it is possible to perform vehicle behavior control and slip amount control, and it is also possible to give priority to vehicle behavior control when lateral acceleration is large. Therefore, even when braking is performed under conditions of high lateral acceleration, vehicle stability can be ensured while appropriately preventing a decrease in braking force compared to when both controls operate independently and simultaneously. .

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a braking force control device of the present invention.

FIG. 2 is a system diagram showing an embodiment of the braking force control device of the present invention.

FIG. 3 is a flowchart showing an example of a control program for the controller in the same example.

FIG. 4 is a diagram showing an example of the characteristics of a weighting coefficient based on lateral acceleration applied in the program.

FIG. 5 is a diagram showing an example of a distribution pattern for explaining a method of distributing vehicle behavior control output.

FIG. 6 is a conceptual diagram illustrating how the same pattern is distributed when vehicle behavior control alone is executed as an example.

[Explanation of symbols]

1L, 1R Left and right front wheels 2L, 2R Left and right rear wheels 3 Brake pedals 5L, 5R, 6L, 6R Wheel cylinder 1
1F, 11R, 12F, 12R Hydraulic pressure control valve 1
6 Controller 17 Steering angle sensor 19, 20, 21, 22 Wheel speed sensor 23
Longitudinal acceleration sensor 24 Lateral acceleration sensor

Claims (1)

[Claims] Claim 1: In a vehicle in which the braking force of each front wheel and/or rear wheel can be independently controlled, a turning state detection means for detecting a turning state of the vehicle and a slip physical quantity used in wheel slip amount control are calculated. A slip physical quantity calculation means,
A lateral acceleration detection means for detecting the lateral acceleration of the vehicle body and a braking force that causes a difference in braking force between the left and right controlled wheels of the vehicle according to the output from the turning state detection means so as to bring the vehicle behavior into target characteristics. and a second braking force control that controls the braking force so that the wheel slip is within a predetermined range based on the output of the slip physical quantity calculation means, braking force control means including priority control means for prioritizing the first braking force control when the detected lateral acceleration is greater than a predetermined value based on the output from the lateral acceleration detection means. Braking force control device.