JP2002120707A - Vehicle motion control device - Google Patents

Abstract

(57) [PROBLEMS] To appropriately control a vacuum booster and a hydraulic pump in a motion control device for a vehicle that performs automatic pressurization control even when a negative pressure of the vacuum booster is small. Performs vehicle motion control. An automatic hydraulic pressure generator having a vacuum booster is drive-controlled in accordance with a vehicle motion state.
The automatic pressure control is performed by controlling the drive of the hydraulic pressure control valve device.
When the amount of the brake fluid in the auxiliary reservoir (RS1) is equal to or more than a predetermined amount, the hydraulic pump (HP1) is switched from the driving position to the holding position and the hydraulic pump (HP1) is maintained in the holding position. Drives and supplies the brake fluid in the auxiliary reservoir to the master cylinder (MC). This allows
The volume of the transformer chamber (B3) of the vacuum booster decreases in a closed state, and the pressure in the transformer chamber increases by the reduced volume and becomes higher than the atmospheric pressure, and the brake fluid pressure of the wheel cylinder increases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle motion control device for performing various controls such as traction control and braking steering control, and more particularly, to driving a vacuum booster irrespective of operation of a brake pedal to control brake hydraulic pressure. A hydraulic pressure control valve is interposed between each of the automatic hydraulic pressure generating devices and the wheel cylinders, which drives and controls the automatic hydraulic pressure generating device and the hydraulic pressure control valve according to the motion state of the vehicle. The present invention also relates to a vehicle motion control device capable of performing automatic pressurization control on a wheel cylinder.

[0002]

2. Description of the Related Art Various means are known as means for obtaining a control braking force in a vehicle motion control device. Among them, a vacuum booster, that is, a device using a vacuum booster is known. Tokiohei 10-508552
No. 6,086,045. The publication comprises a pneumatic braking force booster operable irrespective of the driver's intention and a master brake cylinder connected downstream thereof and having a pressure chamber connected to the individual wheel brakes via a hydraulic device. , The hydraulic device has a return pump, a constant pressure accumulator, a first valve inserted between the master brake cylinder and the wheel brake, and a second valve inserted between the master brake cylinder and the return pump; An operating method of an anti-lock vehicle brake device for driving and / or traction slip control is disclosed. When the pressure supplied by the brake force booster is insufficient, it has been proposed to switch the first valve to the closed position and increase the wheel brake pressure by the return pump.

[0003]

In the operation method of the automobile brake device disclosed in the above publication, when the pressure supplied by the braking force booster (vacuum booster) is insufficient, the wheel brake is increased by the return pump. The first valve and the second valve are indispensable to perform this. That is, the first valve and the second valve are required in addition to the valves constituting the hydraulic pressure control valve device necessary for performing the stable control drive and / or the traction slip control, so that an increase in cost is inevitable.

In view of the above, the present invention provides a motion control apparatus for a vehicle that drives a vacuum booster when a brake pedal is not operated and performs automatic pressurization control on a wheel cylinder, and appropriately controls at least a vacuum booster and a hydraulic pump. Accordingly, it is an object to appropriately control the motion of the vehicle with a simple configuration even when the negative pressure of the vacuum booster is small.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a wheel cylinder mounted on each wheel of a vehicle and a brake fluid independent of operation of a brake pedal. An automatic hydraulic pressure generating device that generates pressure, a hydraulic pressure control valve device that is interposed between the automatic hydraulic pressure generating device and each of the wheel cylinders, and controls a brake hydraulic pressure of each of the wheel cylinders, Drive control of the automatic hydraulic pressure generation device according to the motion state of the vehicle, and drive control of the hydraulic pressure control valve device, at least when the brake pedal is not operated, automatic pressure control for the wheel cylinder. And a control means for controlling the motion of the vehicle, the auxiliary means being connected to the wheel cylinder via the hydraulic pressure control valve device and storing brake fluid. And observers, to connect the suction side to the auxiliary reservoir, comprising a hydraulic pump which connects the discharge side to the upstream side of said pressure control valve device, said automatic hydraulic pressure generator includes
A master cylinder for supplying brake fluid pressure to the wheel cylinder, a constant-pressure chamber for introducing a negative pressure, and a constant-pressure chamber or a variable-pressure chamber communicating with the atmosphere, and communication between the variable-pressure chamber and the atmosphere; and the variable-pressure chamber And a vacuum booster that controls the communication between the pressure chamber and the constant pressure chamber, and boosts the master cylinder in accordance with the pressure difference between the variable pressure chamber and the constant pressure chamber, and shuts off the variable pressure chamber from the constant pressure chamber. A driving position for communicating the variable pressure chamber with the atmosphere in a state where the variable pressure chamber is closed to the constant pressure chamber and the atmosphere, and a release position for releasing the driving position and the holding position.
A booster driving device that switches independently of the brake pedal operation, wherein the control unit is configured to control a brake fluid in the auxiliary reservoir when the amount of the brake fluid is equal to or more than a predetermined amount.
In the state where the booster driving device is switched from the driving position to the holding position and maintained at the holding position, the hydraulic pump is driven to supply the brake fluid in the auxiliary reservoir to the master cylinder. It is.

The control means may determine whether or not the amount of brake fluid in the auxiliary reservoir is equal to or greater than a predetermined amount by monitoring the operating conditions of the hydraulic pump and the hydraulic control valve device. Although it is possible, for example, as described in claim 2, based on the elapsed time after setting the booster drive device to the drive position, it is determined whether the amount of brake fluid in the auxiliary reservoir is equal to or more than a predetermined amount. It can be configured to determine. According to a third aspect of the present invention, the apparatus further includes a fluid amount detecting unit that detects an amount of the brake fluid stored in the auxiliary reservoir, and the control unit performs the control based on a detection result of the fluid amount detecting unit. Alternatively, it may be configured to determine whether the amount of the brake fluid in the auxiliary reservoir is equal to or more than a predetermined amount.

[0007] For example, as set forth in claim 4, the hydraulic pressure control valve device includes a pressure increasing mode in which the wheel cylinder communicates only with the master cylinder, and a pressure reducing mode in which the wheel cylinder communicates only with the auxiliary reservoir. A holding mode for interrupting communication between the wheel cylinder and both the master cylinder and the auxiliary reservoir, and a communication mode for communicating the wheel cylinder with both the master cylinder and the auxiliary reservoir. Of the wheels of the vehicle, the control target wheel and the non-control target wheel of the same hydraulic system, when the pressure increase control is not being performed on the wheel cylinder of the control target wheel, the hydraulic control valve device is driven. The communication mode is set for the wheel cylinder of the non-control target wheel, and the booster driving device is May be configured to set the holding mode to the wheel cylinder of the pressure control valve device to drive the non-controlled wheel is when the holding position. In this case, the control means may be configured such that when the total time in the communication mode exceeds a predetermined time, the amount of the brake fluid in the auxiliary reservoir is equal to or more than a predetermined amount. Can be determined.

According to a sixth aspect of the present invention, the hydraulic pressure control valve device includes a pressure increasing mode in which the wheel cylinder communicates only with the master cylinder, and a pressure reducing mode in which the wheel cylinder communicates only with the auxiliary reservoir. A holding mode for interrupting communication between the wheel cylinder and both the master cylinder and the auxiliary reservoir, and a communication mode for communicating the wheel cylinder with both the master cylinder and the auxiliary reservoir. During a predetermined time before performing automatic pressurization control on the wheel cylinders, the hydraulic pressure control valve device is driven to set the communication mode for all wheel cylinders of the vehicle, and the booster driving device When the elapsed time after setting the driving position to the driving position exceeds a predetermined time, the booster driving device is moved forward. It may be configured to switch the holding position.

According to a seventh aspect of the present invention, the hydraulic pressure control valve device includes a first normally open / close valve interposed between the wheel cylinder and the master cylinder, and the wheel cylinder and the auxiliary cylinder. Normally closed second interposed between the reservoir
In the pressure increase mode, the first on-off valve is in an open position and the second on-off valve is in a closed position,
In the depressurization mode, the first on-off valve is closed and the second on-off valve is open. In the holding mode, the first and second on-off valves are closed. The first and second on-off valves can be configured to be in the open position.

[0010]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, an overall configuration of a vehicle including an embodiment of the present invention will be described with reference to FIG. The engine EG has a throttle control device TH and a fuel injection device F
In the internal combustion engine provided with I, the throttle control device TH controls the main throttle opening of the main throttle valve MT according to the operation of the accelerator pedal AP. Further, the sub-throttle valve ST of the throttle control device TH is driven according to the output of the electronic control unit ECU to control the sub-throttle opening, and the fuel injection device FI
Is driven to control the fuel injection amount. The engine EG of the present embodiment is connected to wheels FL and FR in front of the vehicle via a shift control device GS, and has a so-called front wheel drive system. However, the drive system in the present invention is not limited to this. Absent.

Regarding the braking system, the wheels FL, FR, R
Wheel cylinders Wfl, Wfr, Wr for L and RR, respectively
1, Wrr are mounted, and a brake fluid pressure control device BC is connected to these wheel cylinders Wfl and the like. The wheel FL indicates the front left wheel as viewed from the driver's seat, the wheel FR indicates the front right wheel, the wheel RL indicates the rear left wheel, and the wheel RR indicates the rear right wheel. The brake fluid pressure control device BC will be described later with reference to FIG.

The wheels FL, FR, RL, RR are provided with wheel speed sensors WS1 to WS4, which are connected to the electronic control unit ECU, and which control the rotational speed of each wheel, that is, the number of pulses proportional to the wheel speed. Is input to the electronic control unit ECU. Further, a reservoir liquid level sensor FS, which will be described later, a brake switch BS which is turned on when the brake pedal BP is depressed, a front wheel steering angle sensor SSf which detects a steering angle δf of the front wheels FL and FR of the vehicle, and a lateral acceleration of the vehicle. A lateral acceleration sensor YG for detecting, a yaw rate sensor YS for detecting the yaw rate of the vehicle, and a throttle sensor S for detecting the opening of the main throttle valve MT and the sub throttle valve ST.
S and the like are connected to the electronic control unit ECU. The yaw rate sensor YS detects the rate of change of the vehicle rotation angle (yaw angle) around the vertical axis passing through the center of gravity of the vehicle, that is, the yaw angular velocity (yaw rate), and outputs the detected yaw rate to the electronic control unit ECU as the actual yaw rate γa.

The electronic control unit ECU according to the present embodiment is shown in FIG.
As shown in FIG. 1, a microcomputer CMP comprising a processing unit CPU, a memory ROM, a RAM, an input port IPT, an output port OPT, and the like, which are interconnected via a bus, is provided. The wheel speed sensor WS
1 to WS4, brake switch BS, front wheel steering angle sensor SSf, yaw rate sensor YS, lateral acceleration sensor YG,
Output signals from the throttle sensor SS and the like are configured to be input to the processing unit CPU from the input ports IPT via the amplifier circuits AMP. Further, control signals are output from the output port OPT to the throttle control device TH and the brake fluid pressure control device BC via the drive circuit ACT.

In the microcomputer CMP,
The memory ROM stores programs for various processes including the flowcharts shown in FIGS. 4 to 9, the processing unit CPU executes the programs while an ignition switch (not shown) is closed, and the memory RAM stores the programs. Temporarily stores the variable data required for the execution of For each control such as throttle control,
Alternatively, a plurality of microcomputers may be configured by appropriately combining related controls, and the microcomputers may be electrically connected to each other.

In the braking system including the above-described brake fluid pressure control device BC, as shown in FIG. 2, the master cylinder MC is boosted through the vacuum booster VB in response to the operation of the brake pedal BP, and the master reservoir LRS The pressure of the brake fluid inside is increased and the wheels FR, RL and the wheels FL, R
The master cylinder hydraulic pressure is configured to be output to the two brake hydraulic systems on the R side, and a so-called X pipe is configured. The master cylinder MC is a tandem type master cylinder having two pressure chambers.
The other pressure chamber is connected to the brake fluid pressure system on the side of the wheels FL and RR, and the other pressure chamber is connected to the brake fluid pressure system on the side of the wheels FL and RR. The vacuum booster VB will be described later with reference to FIG.

In the brake hydraulic system for the wheels FR and RL of this embodiment, one of the pressure chambers is connected to the wheel cylinders Wfr and Wrl via a main hydraulic path MF and its branch hydraulic paths MFr and MFl, respectively. Have been. Branch hydraulic path M
Fr and MFl respectively include normally open two-port two-position solenoid valves PC1 and PC2 (hereinafter simply referred to as solenoid valves PC1 and PC2).
2). Further, a discharge-side branch hydraulic pressure path R connected to and connected to the wheel cylinders Wfr and Wrl.
A normally closed type two-port two-position solenoid on-off valve PC5, PC6 (hereinafter, simply referred to as solenoid valve PC5, PC6) is interposed in each of Fr and RFl, and the drainage fluid in which branch hydraulic pressure lines RFr and RFl merge. The pressure line RF is connected to the auxiliary reservoir RS1.

Further, check valves CV1 and CV2 are provided in parallel with the solenoid valves PC1 and PC2, respectively. Check valve CV
1, CV2 permits the flow of brake fluid in the direction of the master cylinder MC and restricts the flow of brake fluid in the direction of the wheel cylinders Wfr, Wrl. The wheel cylinder Wfr is controlled via these check valves CV1, CV2. , Wr
1 is configured to return the brake fluid in the master cylinder MC and thus the master reservoir LRS. Thus, when the brake pedal BP is released, the hydraulic pressure in the wheel cylinders Wfr, Wrl becomes equal to the master cylinder MC
Can quickly follow the hydraulic pressure drop on the side.

In the brake hydraulic system for the wheels FR and RL, a branch hydraulic pressure path M is provided upstream of the solenoid valves PC1 and PC2.
A hydraulic pump HP1 is interposed in a hydraulic passage MFp connected to Fr and MFl, and an auxiliary reservoir RS1 is connected to a suction side of the hydraulic pump HP1 via a check valve CV5. The hydraulic pump HP1 is provided with one electric motor M together with the hydraulic pump HP2.
, The brake fluid is introduced from the suction side, boosted to a predetermined pressure, and output from the discharge side. The auxiliary reservoir RS1 is provided independently of the master reservoir LRS of the master cylinder MC, and can also be referred to as an accumulator. The auxiliary reservoir RS1 includes a piston and a spring, and can store a necessary amount of brake fluid for various controls described later. It is configured as follows. In the present embodiment, a reservoir liquid amount sensor FS for detecting the amount of the brake liquid in the auxiliary reservoir RS1 by the stroke of the piston is provided.

The discharge side of the hydraulic pump HP1 is provided with a check valve CV
6 and the solenoid valves PC1, PC2 via the damper DP1, respectively.
It is connected to the. Check valve CV5 is an auxiliary reservoir RS1
To prevent the flow of the brake fluid to the opposite direction and allow the reverse flow. The check valve CV6 is connected to the hydraulic pump HP1.
This restricts the flow of the brake fluid discharged through the hydraulic pump in a certain direction, and is usually integrally formed in the hydraulic pump HP1. Note that a damper D is provided on the discharge side of the hydraulic pump HP1.
A proportioning valve PV1 is provided in a hydraulic pressure path to the wheel cylinder Wrl on the rear wheel side.

Similarly, in the brake hydraulic system on the wheels FL and RR, a normally open two-port two-position solenoid valve PC
3, PC4, normally closed 2-port 2-position solenoid on-off valve PC
7, PC8, check valve CV3, CV4, CV7, CV8,
An auxiliary reservoir RS2, a damper DP2, and a proportioning valve PV2 are provided, and a hydraulic pump HP2
Is driven by the electric motor M together with the hydraulic pump HP1.

Thus, the above-mentioned solenoid valves PC1 to PC8 constitute a hydraulic pressure control valve device according to the present invention, and these solenoid valves PC1 to PC8 correspond to the above-mentioned electronic control unit ECU.
And various controls including braking steering control are performed. For example, regarding the hydraulic pressure control of the wheel cylinder Wfr of the wheel FR, the on-off valve PC1 is in the open position and the on-off valve PC5 is in the closed position in the pressure increasing mode (and during normal brake operation), and is opened and closed in the pressure reducing mode. The valve PC1 is set to the closed position and the open / close valve PC5 is set to the open position. In the holding mode, both the open / close valves PC1 and PC5 are set to the closed position. In the communication mode, both the open / close valves PC1 and PC5 are set to the open position.

Next, the vacuum booster VB is configured as shown in FIG. 3, and a booster driving device BD for automatically driving the vacuum booster VB at least when the brake pedal is not operated is provided therein. The basic configuration of the vacuum booster VB is the same as the conventional one, and the movable wall B
1, a constant pressure chamber B2 and a variable pressure chamber B3 are formed, and the movable wall B1 is integrally connected to the power piston B4. The constant pressure chamber B2 is configured to always communicate with an intake pipe (not shown) of the engine EG to introduce a negative pressure.
The power piston B4 is connected to an output rod B10 via a fixed core D2 and a reaction disk B9, which will be described later, so that a force can be transmitted. The output rod B10 is connected to the master cylinder MC.

In the power piston B4, there is a vacuum valve V for interrupting communication between the constant pressure chamber B2 and the variable pressure chamber B3.
1 and an air valve V2 for interrupting communication between the transformation chamber B3 and the atmosphere. The vacuum valve V1 includes an annular valve seat V11 formed on the power piston B4, and an elastic valve body V12 detachable from the annular valve seat V11. The air valve V2 includes an elastic valve seat V21 mounted on the elastic valve body V12, and a valve body V22 detachable from the elastic valve seat V21. Valve V22
Is connected to an input rod B6 which can be interlocked with the brake pedal BP, and the elastic valve seat V2 is actuated by the urging force of a spring B7.
1 is urged in the seating direction. Also, the spring B8
Of the elastic valve element V1 of the vacuum valve V1
2 is urged in the direction of sitting on the annular valve seat V11, and the elastic valve seat V21 of the air valve V2 is urged in the direction of sitting on the valve body 22.

In response to the operation of the brake pedal BP (FIG. 2), the vacuum valve V1 and the air valve V2 of the valve mechanism B5 open and close, and the operating force of the brake pedal BP is applied between the constant pressure chamber B2 and the variable pressure chamber B3. Is generated, and as a result, the output amplified by the operation of the brake pedal BP is transmitted to the master cylinder MC.

The booster driving device BD includes a solenoid D1,
Having a fixed core D2 and a movable core D3, and having a solenoid D1
Is for attracting the movable core D3 toward the fixed core D2 when energized, and is electrically connected to the electronic control unit ECU shown in FIG. The fixed core D2 has a power piston B4.
Between the power piston B4 and the reaction disc B9. The movable core D3 is disposed in the solenoid D1 so as to face the fixed core D2, and a magnetic gap D4 is formed between the movable core D3 and the fixed core D2. Movable core D
Numeral 3 is engaged with the valve element V22 of the air valve V2. When the movable core D3 moves relative to the fixed core D2 in a direction to decrease the magnetic gap D4, the valve element V22 of the air valve V2 moves integrally. Is configured.

The booster driving device BD has a driving position for communicating the variable pressure chamber B3 with the atmosphere, and sets the variable pressure chamber B3 to a constant pressure chamber B.
2 and a release position for releasing the drive position and the hold position in a state where the communication with the atmosphere is interrupted, and a release position for releasing the hold position, regardless of the operation of the brake pedal BP. In the release position, the vacuum booster VB is driven by the valve mechanism B5 according to the operation of the brake pedal.

The input rod B6 is a first input rod B61.
And a second input rod B62. The first input rod B61 is integrally connected to the brake pedal BP. The second input rod B62 is relatively movable with respect to the first input rod B61, and is configured to be able to transmit a force to the output rod B10 via the key member B11 by the power piston B4. Therefore, the second input rod B6
When only 2 is driven forward, the first input rod B61 is left, and these first and second input rods B61, B62 are left.
This constitutes a so-called pedal remaining mechanism.

An automatic hydraulic pressure generating device is constituted by the vacuum booster VB (including the booster driving device BD) and the master cylinder MC, and the automatic hydraulic pressure generating device controls at least when the brake pedal is not operated. The operation of the vacuum booster VB and the like when performing automatic pressure control (for example, braking steering control or traction control) on wheels will be described below.

When the automatic pressurization control is started by the electronic control unit ECU, the solenoid D1 is energized, and the movable core D
3 moves to the magnetic gap D4 side, and the valve body V22 of the air valve V2 moves against the movable core D against the urging force of the spring B7.
3 and move together. As a result, the elastic valve body V12 of the vacuum valve V1 is moved by the spring B8 to the annular valve seat V.
11, the communication state between the variable pressure chamber B3 and the constant pressure chamber B2 is cut off. Thereafter, since the valve element V22 of the air valve V2 further moves, the valve element V22 is separated from the elastic valve seat V21, and the atmosphere is introduced into the variable pressure chamber B3. As a result, a differential pressure is generated between the variable pressure chamber B3 and the constant pressure chamber B2, and the power piston B4, the fixed core D2, the reaction disk B9, and the output rod B10 advance to the master cylinder MC (FIG. 2) side. The brake fluid pressure is automatically output from the cylinder MC.

The power piston B4 is connected to the key member B.
After engaging with the key member 11, the second input rod B62 engaging with the key member B11 advances integrally with the power piston B4. At this time, since the forward force of the power piston B4 is not transmitted to the first input rod B61, the first input rod B61 is maintained at the initial position. That is, the brake pedal BP is maintained at the initial position while the vacuum booster VB is automatically driven by the booster driving device BD.

The above-mentioned booster driving device BD, on-off valve PC
The PCs 1 to 8 and the electric motor M are driven and controlled by the electronic control unit ECU, and motion control such as braking steering control (oversteer suppression control or understeer suppression control) is performed. When an ignition switch (not shown) is closed, a motion control program corresponding to the flowchart of FIG. 4 is executed at a calculation cycle of 6 ms.

First, in step 101, the microcomputer CMP is initialized, and various calculated values are cleared. Next, at step 102, the wheel speed sensor WS
1 to WS4 are read, a detection signal of the front wheel steering angle sensor SSf (steering angle δf), a detection signal of the yaw rate sensor YS (actual yaw rate γa), and a detection signal of the lateral acceleration sensor YG (actual lateral acceleration). , Gya)
And the detection signal of the throttle sensor SS are read.

Next, the routine proceeds to step 103, where the wheel speed Vw ** of each wheel (** indicates each wheel FR etc.) is calculated, and these are differentiated to obtain the wheel acceleration DVw ** of each wheel. Can be Subsequently, in step 104, the maximum value of the wheel speed Vw ** of each wheel is calculated as the estimated vehicle speed Vso at the position of the center of gravity of the vehicle (Vso = MAX (Vw **)). Further, an estimated vehicle speed Vso ** is obtained for each wheel based on the wheel speed Vw ** of each wheel, and if necessary, normalization is performed to reduce an error based on a difference between the inner and outer wheels when the vehicle turns. . Further, the estimated vehicle speed Vso is differentiated, and an estimated vehicle acceleration (including an estimated vehicle deceleration having the opposite sign) DVso at the position of the vehicle center of gravity is calculated.

In step 105, the actual slip ratio of each wheel is determined based on the wheel speed Vw ** of each wheel and the estimated vehicle speed Vso ** (or the normalized estimated vehicle speed) obtained in steps 103 and 104. Sa ** is Sa **
= (Vso **-Vw **) / Vso **. Next, in step 106, based on the estimated vehicle body acceleration DVso at the position of the center of gravity of the vehicle and the actual lateral acceleration Gya detected by the lateral acceleration sensor YG, the road surface friction coefficient μ is approximately (DVso
² + Gya ² ) ^1/2 . Further, as means for detecting the road surface friction coefficient, various means such as a sensor for directly detecting the road surface friction coefficient can be used.

Subsequently, in steps 107 and 108, the body slip angle velocity Dβ is calculated, and the body slip angle β is calculated. The vehicle body slip angle β represents the slip of the vehicle body with respect to the traveling direction of the vehicle as an angle, and can be calculated and estimated as follows. That is, the vehicle body slip angular velocity Dβ is a differential value dβ / dt of the vehicle body slip angle β.
In step 107, Dβ = Gya / Vso−γa can be obtained, and this is integrated in step 108 to obtain the vehicle body side slip angle β as β = ∫ (Gya / Vso−γa) dt.

Subsequently, the routine proceeds to step 109, where a braking steering control mode is set, a target slip ratio for the braking steering control is set, and the hydraulic servo control in step 118
The braking torque for each wheel is controlled according to the driving state of the vehicle. This braking steering control is superimposed on control in all control modes described later. Then step 1
Proceeding to 10, it is determined whether or not the anti-skid control start condition is satisfied. If the start condition is satisfied and it is determined that anti-skid control is to be started at the time of braking steering, the initial specific control is immediately terminated and braking is performed in step 111. The control mode is set to perform both the steering control and the anti-skid control.

If it is determined in step 110 that the anti-skid control start condition is not satisfied, the process proceeds to step 112, where it is determined whether the front-rear braking force distribution control start condition is satisfied. When it is determined that the braking force distribution control is started, the routine proceeds to step 113, where a control mode for performing both the braking steering control and the longitudinal braking force distribution control is set. Is satisfied or not. If it is determined that the traction control is started during the brake steering control, the control mode is set to perform both the brake steering control and the traction control in step 115, and if neither control is determined to be started during the brake steering control, In step 116, it is determined whether the brake steering control start condition is satisfied.

If it is determined in step 116 that the braking steering control is to be started, the routine proceeds to step 117, where a control mode for performing only the braking steering control is set. Then, after performing the hydraulic servo control in step 118 based on these control modes, the process returns to step 102. In the front / rear braking force distribution control mode, the distribution of the braking force applied to the rear wheels to the braking force applied to the front wheels is controlled so as to maintain stability of the vehicle during braking of the vehicle. Step 116
If it is determined that the conditions for starting the brake steering control are not satisfied, the solenoids of all the solenoid valves are turned off in step 119, and the steady state shown in FIG. Steps 111, 113, 115,
Based on 117, if necessary, the sub-throttle opening of the throttle control device TH is adjusted according to the driving state of the vehicle, the output of the engine EG is reduced, and the driving force is limited.

FIG. 5 shows the specific processing for setting the target slip ratio for the brake steering control in step 109 of FIG. 4. The brake steering control includes oversteer suppression control and understeer suppression control. A target slip ratio is set for the wheels according to the oversteer suppression control and / or the understeer suppression control. First, in steps 201 and 202, the start and end of the oversteer suppression control and the understeer suppression control are determined.

The start / end determination of the oversteer suppression control performed in step 201 is made based on whether or not the vehicle is in a control area indicated by oblique lines in the map of FIG. That is, if the vehicle enters the control region according to the values of the vehicle body slip angle β and the vehicle body slip angular velocity Dβ at the time of the determination, the oversteer suppression control is started, and if the vehicle leaves the control region, the oversteer suppression control is ended. Control is performed as indicated by the arrow curve. In addition, the braking force of each wheel is controlled such that the control amount increases as the distance from the boundary indicated by the two-dot chain line in FIG. In the map of FIG. 10, the two-dot chain line indicates the threshold value for the control start determination, and the one-dot chain line indicates the threshold value at which the pre-control starts. still,
The pre-control is performed before the braking control in each control mode shown in FIG. 4 starts (before entering the control region), and is also referred to as pre-control.

On the other hand, the start / end determination of the understeer suppression control performed in step 202 is performed based on whether or not the vehicle is in a control area indicated by oblique lines in FIG. That is, at the time of determination, according to the change of the actual lateral acceleration Gya with respect to the target lateral acceleration Gyt, understeer suppression control is started when the vehicle deviates from the ideal state indicated by the one-dot chain line and enters the control region. Is ended, and control is performed as indicated by the arrow curve in FIG.

Subsequently, it is determined in step 203 whether or not the oversteer suppression control is being controlled, and if not, it is determined in step 204 whether or not the understeer suppression control is being controlled. If not, the process returns to the main routine. When it is determined in step 204 that the vehicle is understeer suppression control, the process proceeds to step 205, and the target slip ratio of each wheel is set for understeer suppression control described later. If it is determined in step 203 that the vehicle is in the oversteer suppression control, the process proceeds to step 206 to determine whether or not the vehicle is understeer suppression control. Is set for If it is determined in step 206 that the understeer suppression control is being performed, the oversteer suppression control and the understeer suppression control are performed simultaneously, and in step 208, a target slip ratio for simultaneous control is set.

For setting the target slip ratio for oversteer suppression control in step 207, the vehicle body side slip angle β and the vehicle body side slip angular velocity Dβ are used. The difference between the target lateral acceleration Gyt and the actual lateral acceleration Gya is used for setting the target slip ratio in the understeer suppression control. This target lateral acceleration Gyt is given by Gyt = γ (θf) · Vso
Is determined based on Here, γ (θf) is γ (θ
f) = {θf / (NL)} Vso / (1 + KhVso
² ) where Kh is the stability factor and N
Represents a steering gear ratio, and L represents a wheel base.

The target slip ratio of each wheel in step 205 is as follows: the front wheel on the outside of the turn is set to Stufo, the front wheel on the inside of the turn is set to Stufi, and the rear wheel on the inside of the turn is Sturi.
Is set to As for the sign of the slip ratio (S) shown here, "t" represents "target" and represents "actual measurement" described later.
Compared to "a". "u" is "understeer suppression control"
"R" represents "rear wheel", "o" represents "outside", "
i "represents" inside ", respectively.

The target slip ratio of each wheel in step 207 is set to Stefo for the front wheel on the outside of the turn and to Steri for the rear wheel on the inside of the turn. Here, “e” represents “oversteer suppression control”. And step 208
The target slip ratios of the respective wheels are set such that the front wheel on the outside of the turn is set to Stefo, the front wheel on the inside of the turn is set at Stufi, and the rear wheel on the inside of the turn is set at Sturi. That is,
When the oversteer suppression control and the understeer suppression control are performed simultaneously, the front wheels on the outside of the turn are set in the same manner as the target slip ratio of the oversteer suppression control, and the wheels on the inside of the turn are all set in the same manner as the target slip rate of the understeer suppression control. Is set. In any case, the rear wheels on the outside of the turn (ie, the driven wheels in the front-wheel drive vehicle) are not controlled because the estimated vehicle speed is set.

The target slip ratio Stefo of the front wheel on the outside of the turn used for the oversteer suppression control is Stefo = K1 · β +
K2 · Dβ, and the target slip ratio Steri of the rear wheel inside the turn is set to “0”. Here, K1 and K2 are constants, which are set to values for controlling the pressing direction (direction for increasing the braking force). On the other hand, the target slip ratio used for the understeer suppression control is set as follows based on the deviation ΔGy between the target lateral acceleration Gyt and the actual lateral acceleration Gya. That is, the target slip ratio Stu for the front wheel on the outside of the turn.
fo is set to K3 · ΔGy, and the constant K3 is set to a value for controlling the pressurizing direction (or the depressurizing direction). The target slip ratio Sturi for the rear wheel inside the turn is K
4 ・ ΔGy, and the constant K4 is set to a value for controlling the pressing direction.

FIG. 6 shows the processing of the hydraulic servo control performed in step 118 of FIG. 3. In each wheel, the slip ratio servo control of the wheel cylinder hydraulic pressure is performed. First, steps 205, 207 or 20 described above are performed.
The target slip ratio St ** set in step 8 is used in step 30.
1, and these are read as they are as the target slip rates St ** of the respective wheels.

Subsequently, in step 302, the slip ratio deviation ΔSt ** is calculated for each wheel, and in step 303, the vehicle body acceleration deviation ΔDVso ** is calculated.
In step 302, the target slip ratio S of each wheel
The difference between t ** and the actual slip ratio Sa ** is calculated to determine the slip ratio deviation ΔSt ** (ΔSt ** = St ** − Sa *
*). In step 303, the difference between the estimated vehicle acceleration DVso at the position of the center of gravity of the vehicle and the wheel acceleration DVw ** of the wheel to be controlled is calculated, and the vehicle acceleration deviation ΔDV is calculated.
so ** is required. The actual slip ratio S of each wheel at this time
The calculation of a ** and the vehicle body acceleration deviation ΔDVso ** differ depending on the control mode such as anti-skid control, traction control, etc., but the description thereof will be omitted.

Next, the routine proceeds to step 304, where one parameter Y ** used for brake fluid pressure control in each control mode is calculated as Gs ** · ΔSt **. Where Gs *
* Is a gain, which is set according to the vehicle side slip angle β. In step 305, another parameter X ** used for brake hydraulic pressure control is calculated as Gd ** · ΔDVso **. At this time, the gain Gd ** is a constant value. Thereafter, the routine proceeds to step 306, where the hydraulic mode is set for each wheel, which will be described later with reference to FIG. Subsequently, in step 307, booster drive processing, that is, drive control of the booster drive device BD is performed, which will be described later with reference to FIG.

In accordance with the above hydraulic mode, step 30
At 8, the driving process of the hydraulic control solenoid is performed, the solenoids of the on-off valves PC 1 to PC 8 are driven, and the braking force of each wheel is controlled. Then, the driving process of the motor M is performed in step 309, which will be described later with reference to FIG. In the above-described embodiment, the control is performed based on the slip ratio. However, the control targets of the oversteer suppression control and the understeer suppression control include the slip ratio, the brake fluid pressure of the wheel cylinder of each wheel, and the like. Any value may be used as long as it is a target value corresponding to the braking force to be performed. Note that FIG.
FIG. 6 and FIG. 6 relate to the brake steering control. In the traction control, the automatic pressurization control by the hydraulic servo control is performed, but the description is omitted.

FIG. 7 shows the process of setting the hydraulic pressure mode in step 306 of FIG. 6. First, in step 401, it is determined whether or not the pre-control is being performed. The determination as to whether or not the pre-control is being performed is made based on the control map of FIG.
If the pre-control is being performed, the routine proceeds to step 402, where the hydraulic mode for all wheels is set to the communication mode, and all of the on-off valves PC1 to PC8 are set to the open position. This communication mode
This mode is set to increase the amount of liquid in the auxiliary reservoir as soon as possible.
S2 communicates with the master cylinder MC (and the discharge side of the hydraulic pump) via the open / close valves PC1 to PC8 in the open position. If it is determined in step 401 that the pre-control is not being performed, the process proceeds to step 403, where it is determined whether the braking control is being performed. That is, it is determined whether or not the braking control is being performed in each control mode described in FIG.

If it is determined in step 403 that the braking control is being performed, the process proceeds to step 404 to determine whether or not the wheel to be determined (for example, the wheel FR) is under braking control.
It is determined whether or not the wheel is a control target wheel (control wheel). If so, the process proceeds to step 405. In step 405,
Based on the parameters X ** and Y ** obtained in the above-mentioned steps 305 and 304, the hydraulic mode is set according to the control map shown in FIG. This control map includes a rapid pressure reduction mode area, a pulse pressure reduction mode area,
Each area of the holding mode area, the pulse pressure increasing mode area, and the rapid pressure increasing mode area is set, and in step 405, depending on the values of the parameter X ** and the parameter Y **, which area corresponds to The determination is made (the pressure is increased, reduced, and maintained simply in step 405 in FIG. 7).

On the other hand, if it is determined in step 404 that the wheel is not under braking control, that is, if the wheel is a non-control target wheel (non-controlled wheel), the process proceeds to step 407, where the state of the booster holding flag Fb is determined. Is done. The booster holding flag Fb is set (1) when all communication modes are completed and preparation for setting the booster driving device BD to the holding position is completed as described later. Therefore, this flag can also be referred to as a communication mode completion flag, but at the time of pre-control described later, a predetermined time Kp from when the booster driving device BD is set to the driving position.
Since the flag is set when the time has elapsed, the booster holding flag Fb is a flag for switching the booster driving device BD to the holding position. In step 406 after step 405, the booster holding flag Fb is reset (0).

If it is determined in step 407 that the booster holding flag Fb has been set, the flow advances to step 408 to set the holding mode, and it is determined that the booster holding flag Fb has not been set. Proceeds to step 409. In step 409, it is determined whether or not the control wheels of the same hydraulic system (for example, the wheel RL when the wheel FR is a non-control wheel) are under pressure increase control. The control wheel (wheel FR) is set to the holding mode.

If it is determined in step 409 that the control wheels (wheels RL) of the same hydraulic system are not in the pressure increasing mode, the process proceeds to step 410 and the total time Tt of the communication mode is determined.
It is determined whether or not the communication time Tt has exceeded a predetermined time Kt, and if the predetermined time Kt has elapsed,
The wheel (wheel FL) is set to the holding mode, and Step 4
At 12, the booster holding flag Fb is set (1). If the communication time Tt has not exceeded the predetermined time Kt, the process proceeds to step 402, and the wheel (wheel FR) is set to the communication mode. The setting of the communication mode in step 402 is performed for all wheels in the case of the pre-control as described above, and is performed for each wheel otherwise.

In the above-described step 410, in this embodiment, it is determined whether or not the communication time Tt has exceeded a predetermined time Kt. Instead, the brake fluid in the auxiliary reservoir RS1 or RS2 is determined. It may be determined whether the amount has become equal to or more than the predetermined amount, or whether or not the amount has become equal to or more than the predetermined amount and a predetermined time has elapsed. In this case, in the present embodiment, since the reservoir liquid amount sensor FS is provided as a liquid amount detecting means for detecting the amount of the brake liquid stored in the auxiliary reservoir (for example, RS1), based on the detection result, It can be determined whether the amount of the brake fluid in the auxiliary reservoir (for example, RS1) is equal to or more than a predetermined amount. Alternatively, in step 410, it may be determined whether or not a predetermined time has elapsed since the booster driving device BD was set to the driving position.

On the other hand, if it is determined in step 403 that the braking control is not being performed, the process proceeds to step 413,
All wheels are set to the pressure increasing mode, and normal brake operation is performed. Then, in step 414, the booster holding flag Fb is reset (0).

FIG. 8 shows the booster driving process in step 307 of FIG.
It is determined whether any of the pre-control, the traction control, and the brake steering control is being performed, that is, whether the automatic pressurization control is being performed. If automatic pressurization control is being performed, step 5
In step 02, the state of the booster holding flag Fb is determined. If the booster holding flag Fb is set, the booster driving device BD is set to the holding position, and
Reference numeral 3 denotes a state where the communication with the constant pressure chamber B2 and the atmosphere is cut off. If the booster holding flag Fb has not been set, the process proceeds to step 504, where the booster driving device B
D is a driving position, and the transformation chamber B3 is communicated with the atmosphere.
When it is determined in step 501 that none of the pre-control, the traction control, and the brake steering control is being performed, the process proceeds to step 505, where the booster driving device BD
Is in the release position, and the vacuum booster VB is in the valve mechanism B
5 can be driven.

FIG. 9 shows the motor driving process in step 309 in FIG. 6. First, in step 601, it is determined whether or not the anti-skid control is being performed. If the anti-skid control is being performed, the process proceeds to step 602. Hydraulic pump H
The electric motor M for driving P1 and HP2 is turned on. If it is determined in step 601 that anti-skid control is not being performed, the process proceeds to step 603, and it is further determined whether traction control or braking steering control is being performed.
If the vehicle is under traction control or braking steering control, the process proceeds to step 604, where the state of the booster holding flag Fb is determined. If the booster holding flag Fb is set, the process proceeds to step 605, and the electric motor M is turned on. If the booster holding flag Fb is not set, the process proceeds to step 606, and the electric motor M is turned off. If it is determined in step 603 that neither the traction control nor the braking steering control is being performed, the process proceeds to step 606, and the electric motor M is turned off.

Next, an operation example of the traction control (TRC) will be described with reference to a timing chart of FIG. In FIG. 13, first, traction control starts at point a, non-control wheels (for example, wheels FR) are set to the holding mode, the booster driving device BD is set to the driving position, and the vacuum booster VB starts boosting operation. This allows
The master cylinder hydraulic pressure is increased until it reaches an upper limit value near point f, and a control wheel (for example, wheel RL) in a pressure increasing mode (specifically, in the state of FIG. 2 during traction control in a non-braking state). The wheel cylinder hydraulic pressure of ()) starts increasing after a slight time delay. Next, when the control wheels are set to the holding mode at the point b, the non-control wheels are set to the communication mode. Thereby, the auxiliary reservoir (eg, RS) is opened from the master cylinder MC via the open / close valve (eg, PC1, PC5) at the open position.
Brake fluid is introduced into 1).

As described above, when the control wheels are not under the pressure increase control, the non-control wheels are set to the communication mode (between bc in FIG. 13).
Brake fluid is introduced into an auxiliary reservoir (for example, RS1) during the period between d and e and between fi), and the amount of fluid in the auxiliary reservoir rapidly increases. On the other hand, when the control wheel is under pressure increase control, so-called wraparound may occur, which may adversely affect the braking force control of the control wheel. To avoid this, when the control wheel is not under pressure increase control, Is set to the communication mode.

At the point i, the communication time Tt becomes a predetermined time K
When the time t is exceeded (these times are not shown in FIG. 13), the booster driving device BD is set to the holding position, and the vacuum booster VB (up to the point k at which the control is completed) sets the transformation chamber B3 to the atmospheric pressure and the negative pressure. And the state where the negative pressure is supplied to the constant pressure chamber B2. At the same time, the electric motor M is driven, the hydraulic pumps HP1 and HP2 are started, and the brake fluid is supplied to the master cylinder MC. Thus, the movable wall B1 of the vacuum booster VB retreats due to the output brake fluid pressure of the hydraulic pump (for example, HP1), and its volume decreases in a state where the variable pressure chamber B is sealed. As a result, the pressure in the transformation chamber B3 increases by an amount corresponding to the reduced volume and becomes higher than the atmospheric pressure, and the boosting operation further increases the master cylinder hydraulic pressure from the hydraulic pressure at the point i. Become. Thus, the booster driving device B
D is the holding position, and a hydraulic pump (for example, HP
After 1) is activated, an auxiliary reservoir (eg, RS1)
Since the brake fluid is pumped from the pump, it is necessary to store sufficient brake fluid in the auxiliary reservoir by then. For this reason, the predetermined time Kt is equal to or less than the predetermined amount Kf of the brake fluid in the auxiliary reservoir RS1.
The setting is made as described above.

When the pressure increasing mode is selected for the control wheels at the j point (while the non-control wheels are in the holding mode), the increased master cylinder hydraulic pressure is applied to the wheel cylinders of the control wheels. The wheel cylinder hydraulic pressure is the maximum value P1 of the normal wheel cylinder hydraulic pressure as shown in the lowermost row of FIG.
It rises to a larger value P2. The broken line at the bottom of FIG. 13 indicates the master cylinder hydraulic pressure, and the vacuum booster VB
The pressure in the variable pressure chamber B3 has the same characteristics as the master cylinder hydraulic pressure. When the traction control ends at the point k, the control wheels and the non-control wheels are set to the pressure reduction mode,
The booster driving device BD is set to the release position, and the master cylinder hydraulic pressure and the wheel cylinder hydraulic pressure rapidly decrease.
The hydraulic pump (electric motor M) is turned off when the control wheels and the non-control wheels are in the normal state (pressure increase mode).

The timing chart of FIG. 14 shows an example of the operation of the pre-control. When the pre-control starts at the point s, both the control wheels and the non-control wheels are set to the communication mode, and the booster driving device BD moves the driving position. And the vacuum booster VB starts the boost operation. Thereby, the auxiliary reservoir (for example, RS1) is opened from the master cylinder MC via the open / close valve (for example, PC1, PC5 and PC2, PC6) at the open position.
The brake fluid is introduced into 1), and the fluid volume in the auxiliary reservoir RS1 rapidly increases and becomes equal to or more than the predetermined amount Kf. Then, at point t, traction control (TRC) or braking steering control (VS
When C) starts, the control wheels are set in the set mode (FIG. 14).
In this case, the pressure increase mode is set, and the non-controlled wheels are set in the hold mode.

Thereafter, the wheel cylinder hydraulic pressure of the control wheels is controlled. At a point u after a lapse of a predetermined time Kp after the booster driving device BD is set to the driving position, the booster driving device BD is set to the holding position. At the same time, the electric motor M is driven, the hydraulic pumps HP1 and HP2 are started, and the brake fluid is supplied to the master cylinder MC. As a result, the master cylinder hydraulic pressure is further increased from the hydraulic pressure at the point u by the boost operation of the vacuum booster VB. During this time, for example, at point v, the control wheels are in the pressure reduction mode, but the master cylinder hydraulic pressure is maintained at a high pressure by the vacuum booster VB whose boosting ratio has been increased by the output brake hydraulic pressure of the hydraulic pump HP1. The predetermined time Kp is set according to the characteristics of the vacuum booster VB.

When the pressure increase mode for the control wheel is selected at point w, the master cylinder hydraulic pressure increased from the normal time is applied to the wheel cylinder of the control wheel. 14, the pressure is increased to a maximum value larger than the normal maximum value of the wheel cylinder hydraulic pressure. When the traction control or the brake steering control is completed at the point x, the control wheels and the non-control wheels are set to the pressure reducing mode, the booster driving device BD is set to the release position, and the master cylinder hydraulic pressure and the wheel cylinder hydraulic pressure are suddenly increased. To decline.

As described above, according to the present embodiment, the hydraulic pump (eg, HP1) is driven and the auxiliary reservoir (eg, RS
1) Since the brake fluid in the first cylinder is configured to be supplied to the master cylinder MC, the volume of the transformation chamber B3 of the vacuum booster VB is reduced in a sealed state by the output brake fluid pressure of the hydraulic pump, and the pressure is reduced. The pressure in the chamber B3 increases by the volume decrease and becomes higher than the atmospheric pressure. As a result, the master cylinder hydraulic pressure and, consequently, the brake hydraulic pressure of the wheel cylinders are increased as compared with the case where the atmosphere is simply introduced into the variable pressure chamber B3, and a large braking force can be applied to the control wheels. As described above, a large braking force can be applied to the control wheels without using the first valve and the second valve as in the related art, and the motion control of the vehicle can be appropriately performed even when the negative pressure of the vacuum booster is small. Can be performed.

[0068]

The present invention has the following effects because it is configured as described above. That is, in the vehicle motion control device according to the first aspect, when the amount of the brake fluid in the auxiliary reservoir is equal to or more than the predetermined amount, the booster driving device is switched from the driving position to the holding position and is maintained at the holding position. In this state, the hydraulic pump is driven to supply the brake fluid in the auxiliary reservoir to the master cylinder.
Due to the output brake fluid pressure of the hydraulic pump, the volume of the variable pressure chamber of the vacuum booster decreases in a closed state, and the pressure in the variable pressure chamber increases by the reduced volume and becomes higher than the atmospheric pressure. As a result, the master cylinder hydraulic pressure and, consequently, the brake hydraulic pressure of the wheel cylinder are also ensured. Accordingly, the vehicle motion can be appropriately controlled with a simple configuration without using the first valve and the second valve as in the related art, even when the negative pressure of the vacuum booster is small.

According to the second aspect of the present invention, it is possible to appropriately determine that the amount of brake fluid in the auxiliary reservoir is equal to or more than a predetermined amount. The pump can be driven.

Further, according to the present invention, the brake fluid can be rapidly introduced into the auxiliary reservoir by the communication mode, so that the boosting operation of the vacuum booster can be surely performed during the automatic pressurization control. Can be secured. In this case, the configuration can be made as described in claim 5, whereby it is possible to appropriately determine that the amount of the brake fluid in the auxiliary reservoir is equal to or more than a predetermined amount. Can drive the hydraulic pump.

Alternatively, according to the sixth aspect of the present invention, even in the pre-control, the brake fluid can be rapidly introduced into the auxiliary reservoir by the communication mode. Thus, the boost operation of the vacuum booster can be secured.

Further, if the hydraulic pressure control valve device is configured as described in claim 7, the communication mode can be easily set while the number of solenoid valves remains unchanged, so that an inexpensive device can be provided. Can be configured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a vehicle motion control device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a brake hydraulic system according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a part of a vacuum booster provided in one embodiment of the present invention.

FIG. 4 is a flowchart illustrating a motion control process according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a process of setting a target slip ratio used for brake steering control according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating a hydraulic servo control process according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating a process of setting a hydraulic pressure mode according to an embodiment of the present invention.

FIG. 8 is a flowchart illustrating a booster driving process according to an embodiment of the present invention.

FIG. 9 is a flowchart illustrating a motor driving process according to an embodiment of the present invention.

FIG. 10 is a graph showing a start / end determination area of oversteer suppression control according to an embodiment of the present invention.

FIG. 11 is a graph showing an understeer suppression control start / end determination area according to an embodiment of the present invention.

FIG. 12 is a graph showing a control map according to an embodiment of the present invention.

FIG. 13 is a time chart showing an example of traction control in one embodiment of the present invention.

FIG. 14 is a time chart illustrating an example of pre-control according to an embodiment of the present invention.

[Explanation of symbols]

BP brake pedal, MC master cylinder, VB
Vacuum booster, BD booster drive, M
Electric motor, HP1, HP2 hydraulic pump, LRS
Master reservoir, RS1, RS2 Auxiliary reservoir,
Wfr, Wfl, Wrr, Wrl Wheel cylinder, ECU
Electronic control unit, FR, FL, RR, RL wheels, P
C1 to PC8 Solenoid valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Riji Nishii 2-1-1 Asahi-cho, Kariya-shi, Aichi Aisin Seiki Co., Ltd. (72) Inventor Masahiro Toda 2-1-1 Asahi-cho, Kariya-shi, Aichi Aisin F-term (Reference) in Seiki Co., Ltd.

Claims (7)

[Claims] 1. A wheel cylinder mounted on each wheel of a vehicle, an automatic hydraulic pressure generator for generating a brake hydraulic pressure regardless of operation of a brake pedal, and each of the automatic hydraulic pressure generator and the wheel cylinder. A hydraulic pressure control valve device interposed between the wheel cylinders to control a brake hydraulic pressure of each of the wheel cylinders; and a drive control of the automatic hydraulic pressure generation device according to a motion state of the vehicle, and Control means for controlling the operation of the valve device and automatically controlling the pressure of the wheel cylinder when the brake pedal is not operated to control the motion of the vehicle. An auxiliary reservoir connected to the wheel cylinder via a control valve device for storing brake fluid, and a suction side connected to the auxiliary reservoir and discharged upstream of the hydraulic pressure control valve device. Equipped with a hydraulic pump to connect the outlet side,
The automatic hydraulic pressure generator includes a master cylinder that supplies brake hydraulic pressure to the wheel cylinder, a constant pressure chamber that introduces a negative pressure, and a variable pressure chamber that communicates with the constant pressure chamber or the atmosphere. And a vacuum booster that controls communication between the variable pressure chamber and the constant pressure chamber, and boosts the master cylinder in accordance with a pressure difference between the variable pressure chamber and the constant pressure chamber. A driving position for communicating the variable pressure chamber with the atmosphere in a state where the variable pressure chamber is shut off from the constant pressure chamber, a holding position for holding the variable pressure chamber in a state where the variable pressure chamber is isolated from the constant pressure chamber and the atmosphere, A booster driving device that switches a release position for releasing the position irrespective of the brake pedal operation, wherein the control unit determines that an amount of the brake fluid in the auxiliary reservoir is equal to or more than a predetermined amount. In the state where the booster driving device is switched from the driving position to the holding position and is maintained at the holding position, the hydraulic pump is driven to supply the brake fluid in the auxiliary reservoir to the master cylinder. A motion control device for a vehicle. 2. The control device according to claim 1, wherein the controller determines whether or not the amount of the brake fluid in the auxiliary reservoir is equal to or greater than a predetermined amount based on an elapsed time after the booster driving device is set to the driving position. The motion control device for a vehicle according to claim 1, wherein the motion control device is configured. 3. An apparatus according to claim 1, further comprising a liquid amount detecting means for detecting an amount of the brake liquid stored in the auxiliary reservoir, wherein the control means detects a brake liquid in the auxiliary reservoir based on a detection result of the liquid amount detecting means. 2. The vehicle motion control device according to claim 1, wherein it is configured to determine whether or not the amount is equal to or more than a predetermined amount. 4. The hydraulic pressure control valve device according to claim 1, further comprising: a pressure increasing mode in which the wheel cylinder communicates only with the master cylinder; a pressure reducing mode in which the wheel cylinder communicates only with the auxiliary reservoir; A holding mode for interrupting communication with both of the auxiliary reservoirs, and a communication mode for communicating the wheel cylinders with both the master cylinder and the auxiliary reservoirs are set, and the control unit includes, among the wheels of the vehicle, Regarding the control target wheel and the non-control target wheel of the same hydraulic system, when the pressure increase control is not being performed on the wheel cylinder of the control target wheel, the hydraulic control valve device is driven to drive the wheel cylinder of the non-control target wheel. The hydraulic pressure is set when the communication mode is set for the booster driving device to be in the holding position. 2. The vehicle motion control device according to claim 1, wherein the holding mode is set for a wheel cylinder of the non-control target wheel by driving a control valve device. 5. The control means is configured to determine that the amount of brake fluid in the auxiliary reservoir is equal to or greater than a predetermined amount when a total time of the communication mode exceeds a predetermined time. The vehicle motion control device according to claim 4, wherein: 6. The hydraulic control valve device according to claim 1, further comprising: a pressure increasing mode in which the wheel cylinder communicates only with the master cylinder; a pressure reducing mode in which the wheel cylinder communicates only with the auxiliary reservoir; A holding mode for interrupting communication with both of the auxiliary reservoirs and a communication mode for communicating the wheel cylinders with both the master cylinder and the auxiliary reservoir are set, and the control unit automatically pressurizes the wheel cylinders. During a predetermined time before the control is performed, the passage after setting the communication mode for all the wheel cylinders of the vehicle by driving the hydraulic pressure control valve device and setting the booster driving device to the driving position. When the time exceeds a predetermined time, the booster driving device is switched to the holding position. The vehicle motion control device according to claim 1, wherein: 7. The hydraulic control valve device according to claim 1, wherein a normally open first on-off valve interposed between the wheel cylinder and the master cylinder, and an interposed valve between the wheel cylinder and the auxiliary reservoir. A normally-closed second on-off valve, wherein the first on-off valve is in an open position and the second on-off valve is in a closed position in the pressure increasing mode, and the first on-off valve is in the pressure reducing mode. To the closed position and the second on / off valve to the open position, the first and second on / off valves to the closed position in the holding mode, and the first and second on / off valves to open in the communication mode. The vehicle motion control device according to claim 4, wherein the vehicle motion control device is configured to be a position.