JP2002104157A - Motion control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize an operating sound and to suppress energy consumption, by performing adequate delay control corresponding to a start trend of automatic pressurizing control in the motion control device for a vehicle for performing the automatic pressurizing control. SOLUTION: The automatic pressurizing control is applied to a wheel cylinder at least in a non-operation time of a brake pedal to perform a motion control of the vehicle. In a predetermined time after the motion control of the vehicle, an automatic hydraulic generating device is kept in an operating state, a hydraulic control valve is driven and controlled to perform the delay control to break between the automatic hydraulic generating device and the wheel cylinder. The predetermined time is adjusted based on the motion state (for example, accelerator operating state, or turning state of the vehicle) of the vehicle, and the delay control corresponding to the start trend of the automatic pressurizing control is performed.

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 an automatic hydraulic pressure control system for generating a brake hydraulic pressure regardless of brake pedal operation. A hydraulic pressure control valve is interposed between the generator and each of the wheel cylinders, and the drive pressure of the automatic hydraulic pressure generator is controlled and the hydraulic pressure control valve is driven and controlled according to the motion state of the vehicle. The present invention relates to a vehicle motion control device capable of performing automatic pressurization control.

[0002]

2. Description of the Related Art For example, Japanese Patent Laying-Open No. 2-218663 discloses a hydraulically operated booster in which activation of a booster is controlled only by actuation of a solenoid valve device in response to a signal from an electronic controller, and a vehicle equipped with the same. Braking devices have been proposed. For example, when the drive wheels tend to spin (slip), the booster is automatically activated by a solenoid valve to generate master cylinder hydraulic pressure, and brakes are applied to the spin wheels regardless of brake pedal operation. It is described that the traction force control is performed.

[0003]

In the vehicle braking device disclosed in the above-mentioned publication, the pressurized state and the non-pressurized state are repeated by the automatic pressurizing means such as a booster. Energy consumption of automatic pressurizing means (Negative pressure consumption when using vacuum booster)
Is large.

[0004] In order to cope with this, the timing of disabling the automatic pressurizing means is delayed, and the delay control for shutting off the connection between the automatic pressurizing means and the wheel cylinder is performed, so that the automatic pressurizing means is not activated. The number of repetitions is reduced,
As a result, the energy consumption of the automatic pressurizing means can be reduced. However, during this delay control, the brake fluid pressure is not supplied to the wheel cylinders.
During this time, it is necessary to consider a quick response when the brake pedal is operated. Therefore, the time for performing the delay control is set to be long in a situation where the automatic pressurization control is easily started,
Otherwise, it is desirable to make adjustments in accordance with the tendency of the automatic pressurization control to start, such as setting it short.

In view of the above, the present invention provides a motion control apparatus for a vehicle which performs automatic pressurization control on a wheel cylinder at least when a brake pedal is not operated, and appropriately performs delay control according to the tendency of automatic pressurization control to start. Accordingly, it is an object to reduce operation noise as much as possible and to suppress energy consumption.

[0006]

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 control valve 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; The automatic hydraulic pressure generating device is driven and controlled according to the motion state of the vehicle, and the hydraulic pressure control valve is driven and controlled, and at least when the brake pedal is not operated, the automatic pressure control is performed on the wheel cylinder. Control means for controlling the movement of the vehicle, wherein the control means sets the automatic hydraulic pressure generating device in an operating state for a predetermined time after the end of the movement control of the vehicle. And the drive control of the hydraulic pressure control valve to shut off between the automatic hydraulic pressure generator and each of the wheel cylinders, and the predetermined time is adjusted based on the motion state of the vehicle. Things. That is, since the start tendency of the automatic pressurization control can be determined based on the motion state of the vehicle, the delay control according to the start tendency of the automatic pressurization control can be performed by adjusting the predetermined time based on the motion state of the vehicle. Can be performed.

It is possible to determine whether or not the automatic pressurizing control for the brake steering control and the traction control is easy to start based on the accelerator operation state among the motion states of the vehicle. Therefore, as described in claim 2,
The vehicle may further include accelerator operation detecting means for detecting an accelerator operation state in the vehicle, and the control means may be configured to adjust the predetermined time at least based on a detection result of the accelerator operation detecting means.

The accelerator operation detecting means includes:
There is a means for detecting the depression amount or the depression speed of the accelerator pedal. Specifically, a sensor for directly detecting the operation amount or operation speed of the accelerator pedal may be provided. For example, the throttle opening is detected by a throttle sensor, and the operation amount of the accelerator pedal is estimated based on the detection result. be able to.

Further, it is possible to judge whether or not the automatic pressurizing control for the brake steering control is easy to start based on the turning state of the vehicle, among the moving states of the vehicle. Therefore, as described in claim 3, it is provided with turning state determining means for determining a turning state of the vehicle,
The control means may be configured to adjust the predetermined time at least based on a result of the determination by the turning state determination means.

The turning state determining means may include, for example, a front wheel steering angle sensor for detecting a steering angle of a wheel in front of the vehicle.
At least one of a lateral acceleration sensor for detecting the lateral acceleration of the vehicle and a yaw rate sensor for detecting the yaw rate of the vehicle may be provided, and the turning state of the vehicle may be determined based on the detection result. Furthermore, the target yaw rate deviation, the vehicle body side slip angle or the vehicle body side slip angular velocity may be calculated based on the detection results of the above-mentioned sensors and the like, and the turning state of the vehicle may be determined based on these calculation results.

Further, when the automatic hydraulic pressure generator includes a vacuum booster, for example, the negative intake air pressure of the engine becomes a pressure source at the time of the automatic pressurization control according to the motion state of the vehicle. In the case of, it is possible to cope with the short delay control. Therefore, as set forth in claim 4, a negative pressure detection means for detecting an intake negative pressure of an engine mounted on the vehicle is provided, and the control means determines at least a detection result of the negative pressure detection means. The predetermined time may be adjusted based on the predetermined time.

The negative pressure detecting means includes, for example,
A vehicle speed sensor for detecting a vehicle speed, a wheel speed sensor for detecting a wheel speed, and a speed sensor for detecting an engine speed are provided, and an intake negative pressure is estimated based on the detection result. It can be configured as follows.

[0013]

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.

As for 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. Is input to the electronic control unit ECU. Further, the brake switch BS which is turned on when the brake pedal BP is depressed, the steering angle δf of the wheels FL and FR in front of the vehicle.
, A lateral acceleration sensor YG for detecting the lateral acceleration of the vehicle, a yaw rate sensor YS for detecting the yaw rate of the vehicle, and a throttle sensor SS for detecting the opening of the main throttle valve MT and the sub throttle valve ST. 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 of the present embodiment has a configuration 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 7, 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 the main hydraulic path MF and the 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 on the wheels FR and RL, the 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.

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 side of 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,
A reservoir RS2, a damper DP2, and a proportioning valve PV2 are provided, and the 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 of the present invention. These solenoid valves PC1 to PC8 are driven and controlled by the above-mentioned electronic control unit ECU, and various kinds of control including braking steering control are performed. Control is performed.

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 manifold (not shown) of the engine EG and 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 the 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 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.

The automatic hydraulic pressure generating device of the present invention is constituted by the vacuum booster VB (including the booster driving device BD) and the master cylinder MC. The operation of the vacuum booster VB and the like at the time of performing the automatic pressurization control (for example, the brake steering control and the traction control) on the control target wheel at the time 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.

Then, 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.

Then, the program proceeds to a step 103, wherein the wheel speeds Vw ** of the respective wheels (** indicate the respective wheels FR and the like) are calculated, and these are differentiated to obtain the wheel acceleration DVw ** of the respective wheels. 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.

Then, the routine proceeds to step 109, where the 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, in which 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 in which only the braking steering control is performed is set. Then, after performing hydraulic servo control in step 118 based on these control modes, the process returns to step 101. 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. On the other hand, if it is determined in step 116 that the braking steering control start condition is not satisfied, the process returns to step 102 after setting a later-described non-control time control mode in step 119.
Note that, based on steps 111, 113, 115, and 117, the sub-throttle opening of the throttle control device TH is adjusted according to the operating state of the vehicle, if necessary, and the engine E
The output of G is reduced, and the driving force is limited.

FIG. 5 shows the processing in the non-control-time control mode in step 119 in FIG.
At 01, the delay time Td is set. This delay time Td
Is the time from when the automatic pressurization by the automatic hydraulic pressure generator of the present invention becomes unnecessary to when the automatic hydraulic pressure generator is actually deactivated, as will be described later based on the flowchart shown in FIG. Is set.

At step 202, it is determined whether or not the delay time Td has elapsed after the end of the automatic pressurization control.
Proceed to the following. Then, in step 203, the accelerator operation amount (for example, the accelerator opening) is compared with a predetermined value Ka, and when it is determined that the accelerator operation amount is equal to or more than the predetermined value Ka, that is, when it is determined that the accelerator pedal AP is in the operating state. ,
Then, the process proceeds to step 204. In step 204, it is determined whether the brake switch BS is off. If the brake switch BS is off, the booster driving device BD is activated in step 205, and all wheels are set in the holding mode in step 206. That is, all the normally opened solenoid valves PC1 to PC4 are set to the closed position, and the communication between the master cylinder MC and all the wheel cylinders is cut off.

On the other hand, if it is determined in step 202 that the delay time Td has already passed, step 2
07, the booster driving device BD is deactivated,
In step 208, all wheels are set to the pressure increasing mode.
As described above, the introduction of the delay time Td reduces the number of times the vacuum booster VB is activated and deactivated. As a result, it is possible to reduce the operation noise due to frequent repetition of the pressurized state and the non-pressurized state during the automatic pressurization control, and to suppress the negative pressure consumption.

If it is determined in step 203 that the accelerator operation amount is smaller than the predetermined value Ka, that is, if it is determined that the accelerator pedal AP is in the non-operation state, the process proceeds to step 207 and the booster driving device BD Are deactivated, and in step 208 all wheels are set to the pressure increasing mode. That is, even when the delay time Td has not elapsed, if it is determined that the accelerator pedal AP is in the non-operation state, the booster driving device BD is set to the non-operation state, and all the wheels are set to the pressure increasing mode. You. Therefore, when the brake operation is performed during the automatic pressurization control, it is possible to immediately shift to the normal brake operation.

Further, when it is determined in step 204 that the brake switch BS is in the ON state and the brake pedal BP is in the operating state, the process proceeds to step 207, where the booster driving device BD is deactivated, and in step 20
At 8, all wheels are set to the pressure increase mode. Therefore, if it is determined that the brake pedal BP is in the operating state when the delay time Td has not elapsed, the booster driving device BD
Is set to the non-operating state, and all the wheels are set to the pressure increasing mode, so that it is possible to immediately shift to the normal brake operation.

FIG. 6 shows the setting of the delay time Td in step 201 in FIG. 5. First, in step 301, a predetermined reference time Tk is set as the delay time Td.
Then, in step 302, the turning state of the vehicle is determined. Specifically, the steering angle δf of the front wheels FL and FR of the vehicle is detected by the front wheel steering angle sensor SSf in FIG.
Based on the steering angle δf, the turning state is determined according to, for example, the flowchart of FIG. 7 (this will be described later). The turning state of the vehicle can also be determined based on the detection result of the yaw rate sensor YS or the lateral acceleration sensor YG.

If it is determined in step 302 that the vehicle is in a turning state, it is easy to start automatic pressurization control for braking steering control.
Then, the correction time ΔTs is added to the delay time Td, and the delay time Td is adjusted so as to be longer.
Proceed to 4. On the other hand, if it is determined in step 302 that the vehicle is not in a turning state, step 304
Proceed to.

In step 304, the accelerator operation amount by the accelerator pedal AP (for example, accelerator opening)
Is compared with the predetermined value Ka, and when it is determined that the value is equal to or more than the predetermined value Ka, that is, when it is determined that the accelerator pedal AP is in the operating state and the operation amount is equal to or more than the predetermined value Ka, the process further proceeds to step 305. The correction time ΔTa is added to the delay time Td.
Are added and the delay time Td is adjusted so as to be longer. In contrast, step 30
When it is determined in step 5 that the operation amount of the accelerator pedal AP is less than the predetermined value Ka, the process proceeds to step 306 as it is. Note that the accelerator operation amount is the accelerator pedal AP
The depression amount or the depression speed of the accelerator pedal can be used, and the operation amount or the operation speed of the accelerator pedal may be directly detected.However, for example, the throttle opening is detected by a throttle sensor, and the operation of the accelerator pedal is performed based on the detection result. The quantity can also be estimated.

In step 306, the intake negative pressure of the engine EG mounted on the vehicle is detected, and a correction time ΔTe is set based on the detection result based on the map shown in step 306 of FIG. Proceeding to 307, the correction time ΔTe is added to the delay time Td, the delay time Td is adjusted so as to be longer, and then the process returns to the routine of FIG. That is, when the automatic booster includes the vacuum booster VB as in the present embodiment, the intake negative pressure is a pressure source during the automatic pressurization control. Is required, but when the intake negative pressure is large, it can be dealt with by short-time delay control. Therefore, the correction time ΔTe is set to be shorter as the intake negative pressure increases.

As the negative pressure detecting means, in addition to a negative pressure sensor (not shown) for directly detecting the intake negative pressure, for example,
Based on the detected wheel speeds of the wheel speed sensors WS1 to WS4, the vehicle body speed obtained by the estimation calculation based on the detected wheel speeds, and the detection result of a rotation speed sensor (not shown) for detecting the rotation speed of the engine EG, the intake air load is reduced. It can be configured to estimate the pressure.

In the present embodiment, all of the above steps 302, 304 and 306 are processed, and the delay times Td are adjusted by sequentially adding the correction times ΔTs, ΔTa and ΔTe to the reference time Tk. However, one or two of the correction times ΔTs, ΔTa, and ΔTe may be appropriately selected and added to the reference time Tk to adjust the delay time Td.

FIG. 7 shows an example of the turning state determination processing in step 302 in FIG.
In step 1, the absolute value of the steering angle δf detected by the front wheel steering angle sensor SSf is compared with a predetermined value Kf. If the absolute value of the steering angle δf is larger than the predetermined value Kf, it is determined that the vehicle is turning. Is set (1), the timer Ts is set to the predetermined time value Tks in step 403, and the process returns to the routine of FIG. On the other hand, if it is determined in step 401 that the absolute value of the steering angle δf is equal to or smaller than the predetermined value Kf, the process further proceeds to step 404, where the differential value dδf of the detected steering angle δf is determined.
The absolute value of / dt is compared with a predetermined value Kd. If the absolute value of / dt is larger than the predetermined value Kd, the routine proceeds to step 402, where the turning flag Fs is set.
It is determined whether the timer Ts has become 0 or not.
If the timer Ts is equal to or less than 0, the turning flag Fs is reset (0) in step 406, and the process returns to the routine of FIG. 6. If not, the process proceeds to step 407 and the timer Ts is decremented (Ts− 1) FIG. 6
Return to the routine.

By introducing the delay time Td, it is possible to reduce the operation noise caused by frequent repetition of the pressurized state and the non-pressurized state during the automatic pressurization control, and to suppress the consumption of the negative pressure. Can be. In addition, the delay time Td for performing the delay control is appropriately set in accordance with the tendency of the automatic pressurization control to be set to be long when the automatic pressurization control is easily started, and to be set short when not. You.

In this embodiment, the vacuum booster VB is used as an assisting means of the automatic hydraulic pressure generating device. However, a hydraulic assisting means may be used instead. Alternatively, the automatic hydraulic pressure generator may be constituted by an accumulator or the like that accumulates high-pressure brake fluid.

[0054]

The present invention has the following effects because it is configured as described above. That is, in the vehicle motion control device of the present invention, for a predetermined time after the end of the vehicle motion control,
While maintaining the automatic hydraulic pressure generating device in the operating state, the hydraulic pressure control valve is drive-controlled to disconnect the automatic hydraulic pressure generating device and each of the wheel cylinders from each other, and the predetermined time is set based on the motion state of the vehicle. Since it is configured to adjust, it is possible to reduce the operation noise at the time of the automatic pressurization control and to suppress the energy consumption. Moreover,
Since the predetermined time is configured to be adjusted based on the motion state of the vehicle, it is possible to perform appropriate delay control according to the tendency of the automatic pressurization control to start.

In particular, the vehicle may include an accelerator operation detecting means for detecting an accelerator operation state in the vehicle, and the predetermined time may be adjusted based on at least a detection result of the accelerator operation detecting means. With this configuration, it is possible to determine whether the automatic pressurizing control for the brake steering control and the traction control is easy to start based on the accelerator operation state. Appropriate delay control can be performed.

Further, the vehicle is provided with turning state determining means for determining a turning state of the vehicle, as described in claim 3.
If the predetermined time is adjusted at least based on the determination result of the turning state determination means, it is determined based on the turning state of the vehicle whether or not the automatic pressurizing control for the brake steering control is easily started. Therefore, it is possible to perform appropriate delay control according to the tendency of the automatic pressurization control to start.

Further, it is provided with negative pressure detecting means for detecting the negative pressure of the intake air of the engine.
If the predetermined time is adjusted based on at least the detection result of the negative pressure detecting means, when the automatic hydraulic pressure generator includes a vacuum booster, a short delay control is performed when the intake negative pressure is large. It is possible to respond.

[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 processing in a non-control-time control mode according to the embodiment of the present invention.

FIG. 6 is a flowchart illustrating a process of setting a delay time Td according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating an example of a turning state determination process 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, RS1
Master reservoir, RS2 Auxiliary reservoir, Wfr, W
fl, Wrr, Wrl Wheel cylinder, ECU electronic control unit, FR, FL, RR, RL wheels, PC1 to P
C8 solenoid valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D046 BB00 BB07 BB21 BB29 CC02 EE01 HH02 HH05 HH08 HH16 HH21 HH25 JJ12 KK11 LL10 LL22 LL23

Claims (4)

[Claims] 1. A wheel cylinder mounted on each wheel of a vehicle, an automatic hydraulic pressure generator for generating a brake hydraulic pressure independently of operation of a brake pedal, and each of the automatic hydraulic pressure generator and the wheel cylinder. A hydraulic pressure control valve interposed therebetween 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 the hydraulic pressure control valve Control means for performing automatic pressure control on the wheel cylinder at least when the brake pedal is not operated, and control means for performing motion control of the vehicle, the control means comprising: For a predetermined time after the end of the motion control of the vehicle, the automatic hydraulic pressure generating device is maintained in an operating state, and the hydraulic pressure control valve is drive-controlled to control the automatic hydraulic pressure generating device and the wheel. A motion control device for the vehicle, wherein the predetermined time is adjusted based on the motion state of the vehicle. 2. An accelerator operation detecting means for detecting an accelerator operation state of the vehicle, wherein the control means adjusts the predetermined time at least based on a detection result of the accelerator operation detecting means. The vehicle motion control device according to claim 1, wherein: 3. The vehicle according to claim 1, further comprising: a turning state determining unit configured to determine a turning state of the vehicle, wherein the control unit adjusts the predetermined time based at least on a determination result of the turning state determining unit. The vehicle motion control device according to claim 1, wherein 4. A vehicle according to claim 1, further comprising a negative pressure detecting unit configured to detect an intake negative pressure of an engine mounted on the vehicle, wherein the control unit adjusts the predetermined time at least based on a detection result of the negative pressure detecting unit. 2. The apparatus according to claim 1, wherein
A vehicle motion control device according to any of the preceding claims.