JP2002240703A - Motion control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress noise caused by the operation of a vacuum booster as much as possible by appropriately controlling energization to a booster driving device in a pre-control before starting a motion control in a motion control device automatically conrolling pressurization by the vacuum booster. SOLUTION: This motion control device for a vehicle controls the driving of an automatic hydraulic pressure generating device having the vacuum booster VB according to the motion state of the vehicle and controls the driving of a hydraulic pressure control valve device so as to automatically control the pressurization. Especially, in the pre-control before starting the motion control of the vehicle, the control device controls the driving of the hydraulic pressure control valve device so as to intercept the connection between the automatic hydraulic pressure generating device and a wheel cylinder and, after abruptly increasing a target current of a linear solenoid of the booster driving device BD to a current value right before starting the operation of the motion control, or the starting target value lower than the upper limit value of the target current of the linear solenoid, the control device gently increases it to an adjacency of the upper limit of the target current.

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 device 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 according to the motion state of the vehicle, and controls the hydraulic pressure control valve device. The present invention relates to a vehicle motion control device capable of performing drive control and performing automatic pressurization control on a wheel cylinder.

[0002]

2. Description of the Related Art With respect to traction control in vehicle motion control, Japanese Patent No. 2,784,211 discloses that it takes time from the detection of wheel idling to the increase of brake fluid pressure in a wheel cylinder. Discloses that there is a problem that traction control does not work, and there is a problem that idling increases by that amount, and a traction control method aimed at effectively applying a braking force from an initial stage of idling is disclosed. In this control method, when a wheel spins, a brake booster is activated before the wheel speed information reaches a threshold value for generating a braking force, and at the same time, a hydraulic system between the master cylinder and the wheel cylinder is operated. By shutting off the flow path, the brake booster pressure pressurized by the operation of the brake booster is stored in the hydraulic system,
When the wheel speed information reaches a threshold value, the hydraulic system is released, and the brake hydraulic pressure is applied to the wheel cylinder to generate a braking force. In this publication, a vacuum booster, that is, a vacuum booster is used as a brake booster.

[0003] Further, the present invention relates to an application of a vacuum booster to automatic pressurization control in traction control or the like, wherein the vacuum booster is provided with a booster driving device for driving the vacuum booster independently of brake pedal operation. There is known an apparatus configured to perform traction control or the like by using such a method. As means for driving the booster driving device, a device using a linear solenoid is known, and appropriate control can be performed according to the motion state of the vehicle.

In a general vacuum booster applied to the above-described automatic pressurization control, a constant-pressure chamber and a variable-pressure chamber are formed by movable walls, the movable walls are integrally connected to a power piston, and the constant-pressure chamber is always connected to an engine. It is configured to communicate with the intake pipe and introduce a negative pressure. In the power piston,
A vacuum valve for interrupting communication between the constant pressure chamber and the variable pressure chamber and an air valve for interrupting communication between the variable pressure chamber and the atmosphere are provided. The power piston is connected to the master cylinder via a reaction disk and an output rod. Further, a booster driving device capable of automatically driving the vacuum booster is provided inside the vacuum booster configured as described above in order to perform automatic pressurization control.

Japanese Patent Laid-Open Publication No. Hei 10-258716 discloses a linear solenoid provided to a brake device. A brake fluid pressure control device intended to improve is disclosed. In this publication, it is proposed that when a target hydraulic pressure becomes equal to or more than a predetermined value, a maximum drive current is supplied to a proportional solenoid (linear solenoid) for a predetermined time. It has been proposed to change the time during which the maximum drive current flows in accordance with the time.

[0006]

The above-mentioned Patent No. 2784
The brake booster described in Japanese Patent Publication No. 211 is provided with a switching valve as a booster driving device capable of automatically driving a vacuum booster to perform automatic pressurization control, and is configured to be controlled on / off. ing. On the other hand, in the above-mentioned Japanese Patent Application Laid-Open No. Hei 10-258716, brake fluid pressure control is performed by current control of the linear solenoid. It is controlled so as to be suddenly increased and started up at a stretch, and thereafter to return to the target current. However, regarding the linear solenoid of the booster driving device provided to the automatic hydraulic pressure generating device that generates the brake hydraulic pressure by driving the vacuum booster independently of the operation of the brake pedal, before the movement control such as the traction control is started. However, the following problems occur during automatic hydraulic pressure control when the brake pedal is not operated and the brake pedal is not operated.
The automatic pressurization control when the brake pedal is not operated before the movement control of the vehicle is started has various names such as pre-control, pre-control, and standby control. In the present application, the pre-control will be described. .

That is, when the linear solenoid of the booster driving device is energized to drive the vacuum booster during the pre-control before the movement control such as the traction control is started,
Since the air valve constituting the vacuum booster opens rapidly and the atmosphere is introduced into the variable pressure chamber, a large operating sound is generated, and at the same time, the valve operation is transmitted to the vehicle body via the reaction disk to generate a vibration sound. These sounds are
Due to the non-operation of the brake pedal, noise that cannot be overlooked in terms of NV (that is, noise / vibration) performance is required.

Therefore, the present invention relates to a vehicle motion control device for driving a vacuum booster by a booster driving device when a brake pedal is not operated and performing automatic pressurization control on a wheel cylinder before the vehicle motion control is started. An object of the present invention is to provide a motion control device that suppresses noise caused by the operation of a vacuum booster as much as possible by appropriately controlling energization of a linear solenoid of a booster driving device during pre-control.

[0009]

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 generating device according to the motion state of the vehicle, drive control of the hydraulic pressure control valve device, and automatic pressurization control of the wheel cylinder independently of the operation of the brake pedal. And a control means for performing motion control of the vehicle, wherein the automatic hydraulic pressure generating device has a vacuum operated at least in response to operation of the brake pedal. A booster, and a booster driving device that drives the vacuum booster by driving and controlling a linear solenoid based on a preset target current irrespective of the operation of the brake pedal, wherein the control means controls the motion of the vehicle. When the brake pedal is not operated before starting, the hydraulic pressure control valve device is driven and controlled to disconnect the communication between the automatic hydraulic pressure generation device and the wheel cylinder, and the target current of the linear solenoid is controlled. The current value immediately before the operation of the vacuum booster by the driving of the booster drive device starts for the motion control of the vehicle, and the current value is rapidly increased to a start target value lower than the upper limit value of the target current of the linear solenoid. rear,
The configuration is such that the target current is set so as to gradually increase to near the upper limit value.

According to a second aspect of the present invention, when the brake pedal is not operated before the motion control of the vehicle is started, the control means drives and controls the hydraulic pressure control valve device to generate the automatic hydraulic pressure generation. After the communication between the device and the wheel cylinder is cut off, and the target current of the linear solenoid is rapidly increased to the start target value, a sudden increase switching target value higher than the start target value and lower than the upper limit value. It may be set so as to increase gradually from the target value for the rapid increase switching to the upper limit value.

[0011]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, as shown in FIG.
In response to the operation of the brake pedal BP, the master cylinder MC is boosted via the vacuum booster VB, and the brake fluid in the master reservoir LRS is pressurized and the wheels F
The master cylinder hydraulic pressure is configured to be output to two brake hydraulic systems on the R and RL sides and the wheels FL and RR sides, and a so-called X pipe is configured. The master cylinder MC is a tandem type master cylinder having two pressure chambers. One of the pressure chambers is connected to the brake hydraulic system on the wheels FR and RL, and the other pressure chamber is the brake fluid on the wheels FL and RR. It is connected to the pressure system. 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 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, 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 required amount of brake fluid for various controls. It is configured.

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 fluid pressure 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.

The above-mentioned solenoid valves PC1 to PC8 constitute a hydraulic pressure control valve device according to the present invention. These solenoid valves PC1 to PC8 are driven and controlled by an electronic control unit ECU to provide traction control and braking steering. Various controls such as 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.

Although not shown, the electronic control unit ECU of this embodiment includes a microcomputer including a processing unit, a memory ROM, a RAM, an input port, an output port, and the like, which are interconnected via a bus. . Output signals from a wheel speed sensor, a brake switch, a front wheel steering angle sensor, a yaw rate sensor, a lateral acceleration sensor, a throttle sensor, and the like (all not shown) are input to the processing unit from input ports via an amplifier circuit. Is configured. The output port is configured to output a control signal via a drive circuit.

In the electronic control unit ECU, programs for various processes including the flow charts shown in FIGS. 3 to 5 are stored in a memory ROM, and the processing unit executes the program while an ignition switch (not shown) is closed. And temporarily stores the variable data necessary for executing the program in the memory RAM. Note that a plurality of microcomputers may be configured for each control such as throttle control or a suitable combination of related controls, and may be electrically connected to each other.

Next, the vacuum booster VB is configured as shown in FIG. 2, 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 a constant pressure chamber B2 and a variable pressure chamber B3 are formed by a movable wall B1,
The movable wall B1 is integrally connected to the power piston B4. The constant pressure chamber B2 is always connected to the engine intake pipe (EG in FIG. 1).
(Indicated by)) 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 the elastic valve seat V21.
21 is provided with a detachable valve body V22. 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. 1), 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 has a linear solenoid D1, a fixed core D2 and a movable core D3. The linear solenoid D1 connects the movable core D3 to the fixed core D2 when energized.
The electronic control unit EC shown in FIG.
U is electrically connected. The fixed core D2 is disposed between the power piston B4 and the reaction disc B9, and is moved from the power piston B4 to the reaction disc B9.
The force can be transmitted to The movable core D3 is disposed in the linear 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. The movable core D3 is provided with a valve body 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 body V22 of the air valve V2 moves integrally. The booster drive device BD is configured to be able to switch between a drive position for communicating the variable pressure chamber B3 with the atmosphere and a release position for releasing the drive position irrespective 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.

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

When the automatic pressurization control is started by the electronic control unit ECU, the linear solenoid D1 is energized, the movable core D3 moves toward the magnetic gap D4, and the air valve V
The second valve body V22 moves integrally with the movable core D3 against the urging force of the spring B7. As a result, the spring B
8, the elastic valve body V12 of the vacuum valve V1 is seated on the annular valve seat V11, and the communication between the variable pressure chamber B3 and the constant pressure chamber B2 is cut off. Thereafter, the valve element V2 of the air valve V2
2 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 move forward to the master cylinder MC (FIG. 1) 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.

For example, at the time of traction control, for example, the solenoid on-off valve PC
1, wheel cylinder Wfr by intermittent control of PC5
In response, any of the hydraulic pressure control modes of rapid pressure increase, pulse pressure increase, pulse pressure decrease, and holding is set. As a result, a braking torque is applied to the wheels FR to limit the rotational driving force,
Acceleration slip is prevented, and traction control can be appropriately performed. Acceleration slip prevention control is similarly performed on wheel FL.

More specifically, when an ignition switch (not shown) is closed, a motion control program corresponding to, for example, the flowcharts of FIGS. 3 and 4 is executed at a predetermined calculation cycle (for example, 6 ms). . First step 10
At 1, the microcomputer CMP is initialized, and various calculated values are cleared. Next, at step 102, the detection signals of the wheel speed sensors WS1 to WS4 are read, the detection signal of the front wheel steering angle sensor SSf (steering angle δf), the detection signal of the yaw rate sensor YS (actual yaw rate γa), and the lateral acceleration sensor YG (The actual lateral acceleration, represented by Gya), the detection signal of the throttle sensor SS, and the like.

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 process proceeds to step 109 in FIG. 4 to set the brake steering control mode, a target slip ratio to be provided for the brake steering control is set, and the hydraulic servo control at step 118 controls each wheel according to the driving state of the vehicle. The braking torque is controlled. This braking steering control is superimposed on control in all control modes described later. Thereafter, the process proceeds to step 110, where 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 the anti-skid control is to be started at the time of braking steering, the initial specifying control is immediately terminated and step 111 is performed. Is set to a control mode for performing both braking steering control and 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 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 proceeds to step 119, and it is determined whether the pre-control start condition before the start of traction control is satisfied. If the start condition of the pre-control before the start of the traction control is not satisfied, the process further proceeds to step 120, and it is determined whether or not the start condition of the pre-control before the start of the brake steering control is satisfied.
When it is determined in step 119 that the pre-control start condition before the start of the traction control is satisfied, and when it is determined in step 120 that the pre-control start condition before the start of the brake steering control is satisfied, After the pre-control is performed in step 121, step 101
Return to

The determination as to whether or not the conditions for starting pre-control before the start of traction control or braking steering control in step 119 or step 120 is satisfied is made by using a normal control start threshold as a threshold for pre-control. The pre-control is started when the threshold value is exceeded. For example, in the control map of FIG. 7, the two-dot chain line indicates a threshold value for determining the start of the oversteer suppression control. A determination is made. The dashed line represents the threshold value at which the pre-control starts. Thus, the vehicle body slip angle β at the time of the determination is
If it is determined that the value exceeds the threshold value indicated by the alternate long and short dash line based on the value of the vehicle body slip angular velocity Dβ, the pre-control is started. Further, when the vehicle enters the control region beyond the two-dot chain line, the oversteer suppression control is started, and when the vehicle exits the control region, the oversteer suppression control is terminated, and the control is performed as indicated by the arrow curve in FIG. Note that the braking force of each wheel is controlled so that the control amount increases as the position departs from the boundary indicated by the two-dot chain line in FIG.

If it is determined in step 119 or 120 that the pre-control start condition is satisfied, the pre-control is started in step 121, which will be described later with reference to FIG. If it is determined in steps 119 and 120 that the pre-control start conditions are not satisfied, the solenoids of all the solenoid valves are turned off in step 122 and the steady state shown in FIG. Return to Steps 111 and 11
3, 115, 117, the sub-throttle opening of the throttle control device TH is adjusted according to the driving state of the vehicle as necessary, the output of the engine EG is reduced, and the driving force is limited.

FIG. 5 shows the processing of the hydraulic servo control performed in step 118 of FIG. 4. The slip ratio servo control of the wheel cylinder hydraulic pressure is performed for each wheel. First, steps 111, 113, 115 or 1
The target slip ratio S set according to the seventeenth control mode
t ** is read in step 201, and these are read as they are as the target slip ratio St ** of each wheel.

Subsequently, in step 202, the slip ratio deviation ΔSt ** is calculated for each wheel, and in step 203, the vehicle body acceleration deviation ΔDVso ** is calculated.
In step 202, 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 203, 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 204, where one parameter Y ** used for the 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 205, another parameter X ** to be 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 206, where the hydraulic mode is set for each wheel according to the parameters X ** and Y **. Subsequently, in step 207, booster driving processing, that is, drive control of the booster driving device BD is performed. FIG. 5 relates 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. 6 shows the pre-control processing executed in step 121 of FIG. 3, which will be described with reference to the timing chart of FIG. In FIG. 8, Itm
ax indicates the upper limit of the target current of the linear solenoid D1,
Ix indicates the current value of the linear solenoid D1 when the air valve V2 of the vacuum booster VB is opened by the booster driving device BD, that is, the current value that is the limit of the dead zone, and Ik is the start target at the time of startup during the pre-control. And is set to a value equal to or more than の of the dead zone region limit value Ix.

In FIG. 6, first, in step 301, the actual current Ia of the linear solenoid D1 is compared with the start target value Ik.
In step 2, the target current It is set to the start target value Ik (at time t1 in FIG. 8). In step 301, the actual current Ia
Is determined to be larger than the start target value Ik, step 30
Proceeding to 3, the actual current Ia is further compared with the dead zone region limit value Ix. As a result, when it is determined that the actual current Ia is less than the dead zone region limit value Ix, the process proceeds to step 304, where the target current It is incremented and gradually increases (FIG. 8).
Between t1 and t2). On the other hand, if it is determined in step 303 that the actual current Ia is equal to or greater than the dead zone limit value Ix, the process proceeds to step 305, where the target current It is set to the upper limit value Itmax.
(At time t2 in FIG. 8).

On the other hand, in step 303, the actual current Ia
Is determined to be equal to or greater than the dead zone region limit value Ix, the process proceeds to step 305, the target current It is set to the upper limit value Itmax (at time t2 in FIG. 8), and the process proceeds to step 306. Step 3
06, the electromagnetic valve PC constituting the hydraulic pressure control valve device
The holding signals are output to all the solenoids 1 to PC8, and the communication between the master cylinder MC and all the wheel cylinders is cut off. Step 3 in this state
In step 07, a booster driving process is performed. That is, the target current It is output to the linear solenoid D1 of the booster driving device BD.

As described above, in the present embodiment, the target current I
When t reaches the dead zone region limit value Ix of the sudden increase switching target value, it is set to switch to the upper limit value Itmax at a stroke. However, as shown by the broken line in FIG. After rapidly increasing to the upper limit value I of the target current It
It may be set so as to increase gradually to around tmax. Thus, at the time of the pre-control, generation of the atmospheric suction noise and the vibration noise of the vehicle body when the air valve V2 of the vacuum booster VB is opened by the booster driving device BD is suppressed, and the pre-control is performed smoothly.

The starting target value Ik, dead zone limit value Ix, degree of increase or decrease (gradient) and the like when setting the target current It in the pre-control are different depending on the characteristics of the vacuum booster VB to be controlled. The target current It is set according to the type of the vacuum booster VB mounted on the vehicle. Further, instead of the start target value Ik or the like used as a reference when setting the target current It, the time to reach these values may be used as the determination reference.

After the above pre-control, t3 in FIG.
At that time, the traction control or the braking steering control starts, and the target current It after t3 when the traction control or the braking steering control starts is maintained at the upper limit value Itmax.

[0048]

Since the present invention is configured as described above, the following effects can be obtained. That is, in the vehicle motion control device according to the first aspect, when the brake pedal is not operated before the vehicle motion control is started, the hydraulic pressure control valve device is driven to control the automatic hydraulic pressure generation device and the wheel cylinder. And the target current of the linear solenoid of the booster driving device is the current value immediately before the operation of the vacuum booster is started by the driving of the booster driving device for controlling the motion of the vehicle. After the sudden increase to the start target value lower than the upper limit of the target current of the solenoid, it is set so as to gradually increase to near the upper limit of the target current, and in the motion control device according to claim 2, After the target current of the linear solenoid is rapidly increased to the start target value, it is gradually increased to the sudden increase switching target value, and further from the sudden increase switching target value to the upper limit value. Since it is set to increase rapidly, it is possible to appropriately control the energization of the linear solenoid while minimizing the noise due to the operation of the vacuum booster, Pressurization control can be performed smoothly.

[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 cross-sectional view of a part of a vacuum booster provided in one embodiment of the present invention.

FIG. 3 is a flowchart showing the first half of the vehicle motion control according to the embodiment of the present invention.

FIG. 4 is a flowchart illustrating the latter half of the motion control of the vehicle according to the embodiment of the present invention.

FIG. 5 is a flowchart showing a process of hydraulic servo control in FIG. 4;

FIG. 6 is a flowchart showing a pre-control process in FIG.

FIG. 7 is a graph showing a map used for determining start / end of oversteer suppression control and pre-control in the brake steering control in FIG. 4;

FIG. 8 is a time chart showing an example of a target current setting at the time of pre-control in one 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

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shiro Kadozaki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3D046 BB28 BB29 CC02 DD04 EE01 FF05 HH08 HH17 HH18 HH25 HH36 HH39 HH46 KK12 LL02 LL05 LL10 LL23 LL37 3D048 BB31 CC26 DD02 HH14 HH15 HH18 HH26 HH37 HH42 HH50 HH53 HH59 RR01 RR02

Claims (2)

[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 A vehicle control device comprising: a drive unit for controlling a valve device; and a control unit for performing a motion control of the vehicle by performing an automatic pressurization control on the wheel cylinder independently of an operation of the brake pedal. The pressure generating device is based on a vacuum booster that operates at least in response to the operation of the brake pedal and a target current that is set in advance regardless of the operation of the brake pedal. A booster driving device for driving the vacuum booster by driving and controlling a linear solenoid, wherein the control unit is configured to control the hydraulic pressure control valve device when the brake pedal is not operated before motion control of the vehicle is started. To control the communication between the automatic hydraulic pressure generating device and the wheel cylinder in a state of being interrupted, and to control the target current of the linear solenoid by driving the booster driving device so that the vacuum booster controls the motion of the vehicle. The current value immediately before the start of the operation for the linear solenoid is rapidly increased to a start target value lower than the upper limit value of the target current of the linear solenoid, and then set to gradually increase to near the upper limit value of the target current. A motion control device for a vehicle, comprising: 2. The control means controls the drive of the hydraulic pressure control valve device when the brake pedal is not operated before the motion control of the vehicle is started, and controls the automatic hydraulic pressure generation device and the wheel cylinder. After the communication between the linear solenoid is interrupted, and the target current of the linear solenoid is rapidly increased to the start target value, then gradually increased to a sudden increase switching target value higher than the start target value and lower than the upper limit value, 2. The vehicle motion control device according to claim 1, wherein a setting is made so as to increase rapidly from the sudden increase switching target value to the upper limit value.