JP2002240705A - Motion control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately determine the negative pressure lowering state of a vacuum booster without requiring a special sensor in a motion control device for a vehicle performing an automatic pressurization control 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, controls the driving of a hydraulic pressure control valve, and controls automatic pressurization, at least, in a non-operation of a brake pedal BP. When this motion control device determines that the negative pressure (for example, a suction air negative pressure of an engine EG) of a negative pressure source supplied to the vacuum booster is in the lowering inclination and the automatic pressurization control is performed by a control means for a prescribed times, it determines that the vacuum booster is in the negative pressure lowing state. When performing the automatic pressurization control, a lamp of a pattern under the automatic pressurization control is lit and when the vacuum booster is in the negative pressure lowering state, the lamp of a pattern for lowering the booster negative pressure is lit so as to inform it to a driver.

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 a vacuum booster using a negative pressure of a negative pressure source irrespective of operation of a brake pedal. A hydraulic pressure control valve is interposed between each of the wheel cylinders and an automatic hydraulic pressure generating device that generates a brake hydraulic pressure by driving the vehicle, and controls the automatic hydraulic pressure generating device according to the motion state of the vehicle. The present invention relates to a vehicle motion control device capable of driving and controlling a hydraulic pressure control valve to perform 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. It is disclosed in JP-A-5-213172. The same publication discloses a slip control device that uses a vacuum booster to secure a braking force for a brake control. The slip control device prevents a brake control from being started in a state where a required braking force cannot be obtained. A control device has been proposed. Then, in the non-brake control state, it is determined whether or not a negative pressure required for brake control is held in the first chamber of the vacuum booster based on information from the negative pressure information source, and the required negative pressure is held. It is described that the start of the brake control is prohibited when it is not. Among them, the negative pressure source is the intake negative pressure of the engine, and the negative pressure information source is the accelerator means of the engine and the rotation sensor for detecting the engine speed.

[0003]

In order to detect a decrease in the negative pressure of the vacuum booster disclosed in the above-mentioned publication, a negative pressure sensor may be provided in a constant-pressure chamber of the vacuum booster, for example. However, it is not desirable to use expensive pressure sensors solely for that purpose. As an alternative to this, there is a means for detecting the negative pressure of the intake air of the engine, which is a negative pressure source, but a negative pressure sensor for directly detecting the negative pressure of the intake air of the engine is already installed for another purpose. If not,
For example, as described in the above-mentioned publication, it is appropriate to estimate the intake air negative pressure of the engine by an accelerator means of the engine, a rotation sensor for detecting the engine speed, and the like.

However, when it is determined that the negative pressure required for brake control is not held in the first chamber of the vacuum booster as in the slip control device proposed in the above-mentioned publication, control is immediately started. If the brake control is prohibited by the restricting means, desired movement control cannot be performed. That is, it is desirable to be able to maintain brake control by automatic pressurization as much as possible. It is desirable to notify the driver of the negative pressure reduction state of the vacuum booster (vacuum booster) during this time. For example, in the case where the negative pressure source of the vacuum booster is the intake negative pressure of the engine, when the intake negative pressure decreases, the intake negative pressure increases if the driver decreases the accelerator operation amount (the absolute value of the intake negative pressure). Becomes larger), the driving of the vacuum booster is continued, and the brake control by the automatic pressurization is maintained.
In other words, the vehicle motion control can be prioritized according to the driver's intention.

Therefore, the present invention provides a vehicle motion control apparatus which drives a vacuum booster at least when a brake pedal is not operated and performs automatic pressurization control on a wheel cylinder even when a negative pressure of the vacuum booster is reduced. It is an object of the present invention to appropriately determine a negative pressure reduction state of a vacuum booster without requiring a special sensor in order to appropriately control the motion of a vehicle.

Another object of the present invention, in addition to the above, is to enable a driver to be properly informed of at least the state of reduced vacuum of the vacuum booster to the driver.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a wheel cylinder mounted on each wheel of a vehicle and a negative pressure regardless of the operation of a brake pedal. An automatic hydraulic pressure generator that generates a brake hydraulic pressure by driving a vacuum booster by a negative pressure of a source;
A hydraulic pressure control valve interposed between the automatic hydraulic pressure generating device and each of the wheel cylinders to control a brake hydraulic pressure of each of the wheel cylinders; Control means for controlling the drive of the generator, controlling the drive of the hydraulic pressure control valve, and performing at least the automatic pressurization control on the wheel cylinder when the brake pedal is not operated to control the motion of the vehicle. In the vehicle motion control device, the negative pressure source negative pressure decrease determining means for determining that the negative pressure of the negative pressure source supplied to the vacuum booster is decreasing, and the negative pressure source negative pressure decrease determining means To determine that the negative pressure of the negative pressure source tends to decrease, and to determine that the vacuum booster is in a negative pressure decreasing state when the automatic pressurizing control by the control means has been performed a predetermined number of times. It is obtained by a further comprising a motor negative pressure drop judging means.

The negative pressure source includes an intake pipe of an engine. The negative pressure source negative pressure drop determining means includes a negative pressure sensor for directly detecting the negative pressure of the intake pipe, and an engine speed. And the accelerator operation amount (or throttle opening), and the intake negative pressure of the engine can be estimated based on these detection results. Therefore, for example, when the engine speed is equal to or lower than a predetermined speed, and / or
Or, when the accelerator pedal is operated by a predetermined operation amount or more (or when the throttle opening is equal to or more than the predetermined opening)
In addition, it can be determined that the negative pressure of the negative pressure source tends to decrease.

Further, when the automatic pressurization control by the control means is being executed, the automatic pressurization control is notified by a first notification pattern, and the booster negative pressure drop determination means controls the automatic pressurization control. When it is determined that the vacuum booster is in the negative pressure lowering state, the vacuum booster may include a notifying unit that notifies the vacuum booster with a second notification pattern different from the first notification pattern. In addition, as the notification means, for example, a lamp that lights in a different pattern from the first and second notification patterns may be used.

[0010] Alternatively, there is provided a recovery judging means for judging that the negative pressure of the vacuum booster has been recovered when a predetermined time has elapsed after the stop of the automatic pressurization control by the control means. It may be a thing.

[0011]

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. The rotation speed of each wheel, that is, the number of pulses proportional to the wheel speed, Is input to the electronic control unit ECU. Further, an accelerator opening sensor A indicating the operation amount of the accelerator pedal AP
S, a rotation sensor ES for detecting the number of rotations of the engine EG,
The brake switch BS which is turned on when the brake pedal BP is depressed, the steering angle δ of the wheels FL and FR in front of the vehicle.
f, front wheel steering angle sensor SSf for detecting the lateral acceleration of the vehicle, lateral acceleration sensor YG for detecting the lateral acceleration of the vehicle, yaw rate sensor YS for detecting the yaw rate of the vehicle, and a throttle sensor for detecting the opening of the main throttle valve MT and the sub throttle valve ST. SS 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 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 connected to each other via a bus is provided. The wheel speed sensor WS
1 to WS4, accelerator opening sensor AS, rotation sensor E
Output signals of the S, brake switch BS, front wheel steering angle sensor SSf, yaw rate sensor YS, lateral acceleration sensor YG, throttle sensor SS, etc. are input to the processing unit CPU from the input port IPT via the amplifier circuit AMP. Have been. Also, the output port OP
T from the throttle control device T via the drive circuit ACT.
The control signals are output to the H and brake fluid pressure control devices BC, respectively.

In the microcomputer CMP,
The memory ROM stores programs for various processes including the flowcharts shown in FIGS. 4 to 6, 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. 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 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.
And a reaction disc B9, and the force can be transmitted from the power piston B4 to 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 includes 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, the automatic hydraulic pressure generator 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 a 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, 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 detection signal of the lateral acceleration sensor YG (actual lateral acceleration). , Gya), the detection signal of the throttle sensor SS, the rotation sensor E
The detection signal of S, the detection signal of the accelerator opening sensor AS, and the like are read.

Then, the program proceeds to a step 103, wherein the wheel speeds Vw ** of the respective wheels (** represent 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 vehicle body slip angular velocity Dβ is calculated, and the vehicle 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 a step 109, wherein a booster negative pressure drop judgment is made, which will be described later with reference to FIG. Then, the routine proceeds to step 110, where the braking steering control mode is set, a target slip ratio for the braking steering control is set, and the braking torque for each wheel is controlled by the hydraulic servo control of step 119 according to the driving state of the vehicle. . This braking steering control is superimposed on control in all control modes described later. Thereafter, the process proceeds to step 111, 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 ends immediately and step 112 Is set to a control mode for performing both braking steering control and anti-skid control.

If it is determined in step 111 that the anti-skid control start condition is not satisfied, the process proceeds to step 113, where it is determined whether the front-rear braking force distribution control start condition is satisfied. If it is determined that the braking force distribution control is to be started, the routine proceeds to step 114, 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 braking steering control, the control mode is set to perform both the braking steering control and the traction control in step 116, and if neither control is determined to be started during the braking steering control, In step 117, it is determined whether the brake steering control start condition is satisfied.

If it is determined in step 117 that the braking steering control has been started, the routine proceeds to step 118, where a control mode in which only the braking steering control is performed is set. Then, after performing hydraulic servo control in step 119 based on these control modes, a notification process is performed in step 121 (this notification process will be described later with reference to FIG. 6).
Thereafter, 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.

If it is determined in step 117 that the brake steering control start condition is not satisfied, step 120 is executed.
After the solenoids of all the solenoid valves are turned off and the steady state shown in FIG. 2 is set, the process returns to step 102 via the notification process of step 121. Steps 112, 114,
Based on 116 and 118, the sub-throttle opening of throttle control device TH is adjusted according to the driving state of the vehicle as necessary, the output of engine EG is reduced, and the driving force is limited.

FIG. 5 shows the specific processing of the booster negative pressure drop determination in step 109 of FIG. 4. First, in step 201, the previous automatic pressurizing control flag F
The state of c (n-1) is determined. For example, when the brake steering control or the traction control starts, the automatic pressurizing control flag Fc
(n) is set (1) and is set (1) while the automatic pressurization control for the brake steering control and the traction control is being performed. Note that Fc (n) represents the current (n) automatic pressurizing control flag, and Fc (n-1) represents the previous (n-1) automatic pressurizing control flag. Thus, in step 201, in the previous cycle, the automatic pressurizing control in-progress flag Fc (n-1)
Is in the reset (0) state and the automatic pressurizing control is not being performed, and in step 202, the automatic pressurizing control-in-progress flag Fc (n) is set (1) in this cycle, and If it is determined that
In step 03, the automatic pressurization control counter is counted up (Nc ← Nc + 1). That is, the automatic pressurizing control counter is counted up at the start timing of the automatic pressurizing control.

Then, in step 204, the state of the booster negative pressure reduction flag Fd is determined. Since the booster negative pressure drop flag Fd is reset and Fd = 0 at the first time of the control cycle, the process proceeds to step 212 and thereafter.
Whether or not the vacuum booster VB is in the negative pressure drop state is determined as follows. First, at step 212, it is determined whether or not the negative pressure of the negative pressure source has a tendency to decrease.
For example, in this embodiment, when the detected engine speed of the rotation sensor ES is equal to or less than a predetermined speed, the accelerator opening sensor AS
Is greater than or equal to the predetermined opening, it is determined that the intake negative pressure of the engine EG, which is the negative pressure source, tends to decrease.
Note that a throttle sensor SS may be used instead of the accelerator opening sensor AS.

If it is determined in step 212 that the negative pressure of the negative pressure source is decreasing, it is further determined in step 213 whether or not the value Nc of the automatic pressure control counter has exceeded a predetermined value K1. When the automatic pressurization control is performed a predetermined number of times and the value Nc of the automatic pressurization control counter exceeds a predetermined value K1, it is determined that the vacuum booster VB is in a negative pressure lowering state, and the routine proceeds to step 214, where the booster negative pressure is reduced. The decrease flag Fd is set (1), and furthermore, step 21
At 5, the value Nr of a negative pressure recovery counter described later is reset (0). When it is determined in step 212 that the negative pressure of the negative pressure source does not tend to decrease, and in step 21
In step 3, the value Nc of the automatic pressurization control counter is equal to the predetermined value K1.
If it is determined that the pressure is less than or equal to the value in step 216, the state of the automatic pressurizing control flag Fc (n) is changed to the automatic pressurizing control flag Fc (n).
The state is set to c (n-1) (that is, updated), and the process returns to the main routine of FIG.

Next, when it is determined in step 204 that the booster negative pressure reduction flag Fd is set (1), the negative pressure of the negative pressure source tends to decrease in step 205 as in step 212 described above. Is determined. If it is determined in step 205 that the negative pressure of the negative pressure source does not tend to decrease, the process proceeds to step 206, where the state of the present automatic pressurizing control flag Fc (n) is determined. If the current automatic pressurization control flag Fc (n) is set (1), the vacuum booster VB is in the operating state and the negative pressure is consumed. Nr is cleared. When it is determined in step 205 that the negative pressure of the negative pressure source is decreasing, the process also proceeds to step 207. In the negative pressure recovery counter (Nr), the automatic pressurizing control flag Fc (n) is reset (0) (the automatic pressurizing control is not performed). Therefore, the negative pressure in the constant pressure chamber B2 of the vacuum booster VB is reduced. If does not decrease, the count is incremented at step 208 in each control cycle (Nr ← Nr + 1).

Then, the process proceeds to a step 209, wherein it is determined whether or not the value Nr of the negative pressure recovery counter exceeds a predetermined value K2. When a predetermined time has elapsed after the stop of the automatic pressurization control and the value Nr of the negative pressure recovery counter has exceeded a predetermined value K2,
It is determined that the negative pressure in the constant pressure chamber B2 of the vacuum booster VB is in a recovery state, the booster negative pressure reduction flag Fd is reset (0) in step 210, and the value Nc of the automatic pressure control counter is reset in step 211. Cleared (0), the state of the automatic pressurizing control flag Fc (n) is changed to the state of the automatic pressurizing control flag Fc (n-1) in step 216, and the process returns to the main routine of FIG. On the other hand, at step 209, the value Nr of the negative pressure recovery counter becomes the predetermined value K2.
When it is determined as follows, the process proceeds to step 216 and FIG.
Return to the main routine.

Next, the notification process in step 121 of FIG. 4 will be described with reference to FIG. First, in step 301, the state of the booster negative pressure reduction flag Fd is determined, and if it is set (1), step 3
Proceeding to 02, it is notified that the vacuum booster VB is in a negative pressure drop state. The notification means includes a display, a lamp, and a buzzer. In the present embodiment, a lamp (not shown) is used.
When the negative pressure in the constant pressure chamber B2 of B is reduced, the vacuum booster VB is in a state of reduced negative pressure for the driver by lighting in the booster negative pressure reduction pattern (corresponding to the second notification pattern of the present invention). Be informed.

On the other hand, if the booster negative pressure drop flag Fd is reset (0), the routine proceeds to step 303,
Further, the state of the automatic pressurizing control flag Fc (n) is determined.
If the automatic pressurizing control flag Fc (n) is set, it is notified in step 304 that the automatic pressurizing control is being performed. That is, in step 304, using the above-mentioned ramp for negative pressure drop notification, the automatic pressurizing control pattern (the first pattern of the present invention) different from the booster negative pressure drop pattern.
(Corresponding to the notification pattern described above), the driver is notified that the automatic pressurization control is being performed. Here, the booster negative pressure lowering pattern is a pattern that is always lit while the negative pressure lowering flag is set, and the automatic pressurizing control pattern is, for example, the automatic pressurizing control flag is set. In the meantime, the pattern may blink. If it is determined in step 303 that the automatic pressurizing control in-progress flag Fc (n) is not set,
Proceeding to step 305, the lamp is turned off. In this embodiment, the common lamp is used to notify the negative pressure drop state and the automatic pressurization control is being performed. However, it is also possible to use a dedicated lamp to notify each of them.

[0046]

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, the negative pressure source negative pressure drop determining means determines that the negative pressure of the negative pressure source is in a tendency to decrease, and the automatic pressure control by the control means is performed. Since the vacuum booster is configured to determine that the negative pressure is reduced when the predetermined number of times have been performed, the negative pressure reduction state of the vacuum booster is appropriately and inexpensively determined without providing a sensor directly in the vacuum booster. be able to. The determination result of the negative pressure drop state can be used for various purposes.

Further, if the notifying means according to the second aspect is provided, it is possible to notify that the automatic pressurizing control is being executed by the first notifying pattern,
The driver can be notified by the second notification pattern that the vacuum booster is in the negative pressure reduction state. Therefore, when notified by the second notification pattern, for example, the driver can maintain the automatic pressurization control by reducing the accelerator operation amount and give priority to the vehicle motion control. In addition, it is possible to notify both of the automatic pressurization control execution and the negative pressure reduction state of the vacuum booster by using a common notifying unit, so that cost reduction can be achieved.

In the vehicle motion control apparatus according to the first aspect, if the recovery determining means according to the third aspect is further provided, it is possible to easily determine the negative pressure recovery of the vacuum booster. After the recovery from the negative pressure, it is possible to immediately return to the automatic pressurization control.

[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 showing a specific process of a booster negative pressure drop determination in one embodiment of the present invention.

FIG. 6 is a flowchart illustrating a specific process of a notification process according to the 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

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Claims (3)

[Claims] An automatic hydraulic pressure generating device that generates a brake hydraulic pressure by driving a vacuum booster by a negative pressure of a negative pressure source irrespective of an operation of a brake pedal, and a wheel cylinder mounted on each wheel of the vehicle; A hydraulic pressure control valve interposed between the automatic hydraulic pressure generating device and each of the wheel cylinders to control a brake hydraulic pressure of each of the wheel cylinders; Along with controlling the driving of the generator, controlling the driving of the hydraulic control valve,
At least the control means for performing automatic pressurization control on the wheel cylinders when the brake pedal is not operated and controlling the motion of the vehicle. The negative pressure source supplied to the vacuum booster Negative pressure source negative pressure decrease determining means for determining that the negative pressure of the negative pressure is decreasing, and determining that the negative pressure of the negative pressure source is decreasing by the negative pressure source negative pressure decreasing determining means, and A vehicle motion control device comprising: a booster negative pressure drop determining unit that determines that the vacuum booster is in a negative pressure drop state when the automatic pressurizing control by the control unit has been performed a predetermined number of times. 2. The automatic pressurization control by the control means is notified by a first notification pattern when the control is being executed, and the vacuum booster is in a negative pressure reduction state by the booster negative pressure reduction determination means. 2. The vehicle motion control device according to claim 1, further comprising a notifying unit for notifying when the determination is made by a second notification pattern different from the first notification pattern. 3. A recovery judging means for judging that the negative pressure of the vacuum booster has recovered when a predetermined time has elapsed after the automatic pressurization control by the control means is stopped. Vehicle motion control device.