JP2643969B2 - Skid control - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skid control device that prevents skid of a wheel during both braking and acceleration, and in particular, reduces engine output due to skid prevention during acceleration. The present invention relates to a skid control device that minimizes

`` Conventional technology '' Conventionally, a so-called traction control device for preventing skid of a wheel at the time of sudden start of a vehicle detects a skid of the wheel by some means and narrows an accelerator opening, or adjusts an ignition timing. A method of reducing the output of the engine by delaying the output, that is, a method of controlling the output of the engine has been dominant.

To explain the principle of this control, the rotation of the wheel, if the angular acceleration, torque T _R to receive from the road surface, the braking torque T _B, the driving torque T _A, and, axle system inertia I
Is determined as in equation (1).

I = T _A −T _R −T _B (1) (where T _R is negative during braking) Here, the slip of the wheel is considered assuming that the wheel is in an acceleration state. A relative speed is generated between the wheel peripheral speed and the vehicle speed. From the relative speed, λ = 1−Rω / v (2) (where Rω is the wheel peripheral speed and v is the vehicle speed). Is determined, and the road surface friction coefficient μ is determined from the slip ratio λ and the road surface condition. It is known that the value of μ changes depending on the road surface condition, but the maximum value occurs in the range of the slip ratio λ ≒ −0.1 to −0.3.

Therefore, when the vehicle speed v is known, the value of -0.
If the wheel peripheral speed Rω is controlled so as to obtain λ of about −0.2 which is a substantially intermediate value between 1 and −0.3, skid can be prevented almost accurately.

And it from equation (1), lambda increases the drive torque T _A in the case greater than -0.2, and when -0.2 smaller than increasing or braking torque T _B to reduce the driving torque T _A As described above, in the conventional skid control (traction control) method, the drive torque T _A can be controlled by adjusting the accelerator opening, the ignition timing, and the like. The engine was controlled to reduce the engine.

"Problems to be Solved by the Invention" However, in a general automobile, since a differential gear is interposed between the engine and the axle of the driving wheels, the so-called right and left wheels contact with a road surface having a different friction coefficient μ. Problems may occur in the split μ state.

That is, when one of the wheels is on the Loμ road surface, the wheel tries to spin, and when this is detected by the skid control system (for example, it can be detected by increasing the wheel circumferential acceleration R), the driving torque T _A is increased. The engine is controlled to reduce the power, and accordingly, the driving torque of the other wheel on the Hiμ side connected to the one wheel via a differential gear is also reduced. Therefore, there is a problem that acceleration is inevitably slowed down due to a shortage of driving torque on the Hiμ side at which a larger driving force is to be obtained, and drivability is reduced.

The present invention has been proposed in view of the above circumstances, and an object of the present invention is to provide a skid control device capable of preventing a skid while minimizing a decrease in engine output.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a wheel speed detecting means provided at least on a driving wheel to measure a wheel peripheral speed, and a vehicle speed based on data detected by the wheel speed detecting means. Estimating means for estimating, a calculating means for calculating the acceleration of the wheel from the detection data of the wheel speed detecting means, and a hydraulic system for transmitting the hydraulic pressure generated from the master cylinder to the brake calipers of the driving wheels and the driven wheels, respectively. A valve for opening and closing a hydraulic system toward a driving wheel, a valve for opening and closing a hydraulic system toward a driven wheel, and a hydraulic pressure generated in the master cylinder by receiving a supply of operating pressure based on operation of a brake pedal. A booster, a switching valve provided in the booster for supplying an operating pressure to the booster irrespective of operation of a brake pedal, and a suction valve provided in an intake system of the engine. An auxiliary accelerator for restricting the flow rate, a control circuit for operating the auxiliary accelerator to adjust the intake flow rate, valves provided for the hydraulic and negative pressure systems, and a control circuit for the auxiliary accelerator. The controller determines the degree of skid state of both drive wheels from the wheel peripheral speed and acceleration of both drive wheels and the estimated vehicle speed, and operates the switching valve regardless of the degree of skid. The operating pressure is applied to the booster to supply hydraulic pressure to the brake hydraulic system of the skid drive wheel to perform braking, and to apply the brake hydraulic system of the driven wheel to the drive wheel. While the valve is operated to disconnect from the pressure system, when the skid advances beyond a certain limit, the auxiliary accelerator limits the intake air flow.

[Operation] With the above configuration, when the driving wheel is in the skid state, the pressure is applied to the brake hydraulic system, and the pressure is not applied to the brake hydraulic system of the driven wheel. In this state, In the case of a relatively light skid state such as when only one of the drive wheels is skid, the brake of the drive wheel is operated without reducing the rotation of the engine, and both drive wheels are skid. In the case of a severe skid condition such as
The corresponding wheel can be recovered from the skid.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, the configuration of the skid control system will be described with reference to FIG.

This control system is applied to an anti-skid control applied to a vehicle braking system of a 4-sensor 4-channel type (a system in which a vehicle speed sensor is provided for each wheel and each wheel is braked by an independent hydraulic system). The engine output control is added.

Reference numeral 1 denotes, for example, Japanese Patent Application No.
This is a booster provided with a so-called control chamber as described in No. 14063. The booster 1 performs a normal boosting function of amplifying the depressing force of the brake pedal 2 and transmitting it to the master cylinder 3 when connected to a negative pressure source such as an engine intake system to be described later.
It has a function of generating a braking force regardless of the operation of the brake pedal 2 in other words, regardless of the operation of the brake pedal 2, regardless of the operation of the driver, by being cut off from the negative pressure source and entering the atmosphere communication state. It is. That is, in the booster described above, when atmospheric pressure is applied to the working pressure chamber, the master cylinder can be automatically operated by the pressure difference to generate hydraulic pressure.

The master cylinder 3 is provided with brake calipers 4A to 4D for front left, front right, rear left and rear right wheels (in the embodiment, drive wheels are front wheels) by the pressure applied from the booster 1. The brake calipers 4A to 4D act on the brake discs 5A to 5D, which rotate integrally with the axle, to apply a braking force corresponding to the hydraulic pressure. I have. Changes in the number of revolutions of the brake discs 5A to 5D (changes in wheel peripheral speed) are detected by wheel speed sensors 6A to 6D, respectively.

Next, the configuration of a hydraulic system from the master cylinder 3 to the brake caliper 4A of the left front wheel will be described.

The brake caliper 4A is connected to the output side of the master cylinder 3 via a normally open valve 7. The normally open valve 7 is always kept in the “open” state, and is switched to “closed” by being energized in the anti-skid control. A check valve 8 is provided in parallel with the normally open valve 7 to allow the return of the pressure oil from the caliper 4 side to the master cylinder 3 side. A pipeline between the caliper 4A and the normally open valve 7 is connected to a reservoir (accumulator) 11 and a suction side of a hydraulic pump 12 via a normally closed valve 9 and a check valve 10, and is connected to a brake. A hydraulic pressure release system is configured to release the hydraulic pressure supplied to the caliper 4A and stop its operation. The discharge side of the hydraulic pump 12 is connected to a pipe from the master cylinder 3 to the caliper 4A via a check valve 13, and the liquid discharged by the hydraulic pressure release system is connected to a hydraulic system for driving. I am going to put it back.

On the other hand, the output of the master cylinder 3 is branched before the normally open valve 7, further adjusted to a pressure lower than the hydraulic system of the front wheels by the pressure control valve 14, and then, through the normally open valve 15. It is supplied to the caliper 4D on the right rear wheel. The normally open valve 15 is provided with a bypass flow path having a check valve 8 in parallel, as in the case of the normally open valve 7 of the left front wheel system. The caliper 4D
A line between the normally open valve 15 and the normally open valve 15 is connected through a normally closed valve 16 and a check valve 10 to the normally closed valve 9 of the hydraulic system of the left front wheel.
And the reservoir 11 and the hydraulic pump 12 in parallel.

With the above configuration, the left front wheel 4A and the right rear wheel 4D are individually controlled in hydraulic pressure to prevent skid by controlling the normally-closed valves 9 and 16, respectively. A hydraulic pressure control system in which the hydraulic pressure is recovered by the reservoir 11 and the hydraulic pump 12 is configured.

On the other hand, the calipers 4B and 4C of the right front wheel and the left rear wheel are controlled by a hydraulic system having the same configuration as the left front wheel and the right rear wheel. That is, the caliper 4B of the right front wheel is connected to the master cylinder 3 via the normally open valve 7 ', and the caliper 4C of the left rear wheel is connected to the master cylinder 3 via the normally open valve 15'.
They are connected to a reservoir 11 'and a hydraulic pump 12' via normally closed valves 9 'and 16' provided respectively, and constitute a hydraulic system similar to the left front wheel to the right rear wheel system.

The intake line 20 connected to the intake valve to the engine adjusts the amount of air suction by operating the main intake damper 22 via the accelerator 21, thereby adjusting the amount of air-fuel mixture supplied to the engine. And a function of applying a negative pressure to the booster 1 by being connected to the booster 1 via the switching valve 23. An auxiliary damper 24 is provided in the intake pipe 20, and the auxiliary damper 24 is operated by a servomotor 26 controlled by a motor control circuit 25 to correct an increase or decrease in the air flow rate due to the damper 22. Have a function. That is, when the accelerator pedal 21 is suddenly depressed and the main intake damper 22 is opened, the auxiliary damper 24 is opened with a delay after a certain time from this opening, so that the mixture of the air-fuel mixture is increased in accordance with the engine output rise. The flow rate is appropriately increased.

Further, the brake pedal 1 has a switch BSW,
The accelerator pedal 21 is provided with a switch ASW to detect the depression of each switch. The signals of these switches are used for checking the system or for fail-safe operation, but the details of the signal processing are not relevant to the present invention, and the description thereof will be omitted.

Furthermore, the detection signals of the wheel speed sensors 6A to 6D, the brake sensor VBSW, and the accelerator sensor ASW are supplied to a controller 27 including a microprocessor, and the controller 27 performs arithmetic processing on the signals from the respective sensors to perform the processing. Each solenoid valve (normally closed valve, normally open valve, and switching valve) 7.9.15.16.7'.9'.15 '.
By supplying control signals to the pump control units 16 'and 23, the pumps 12 and 12', and the motor control circuit 25, the brake calipers 4A to 4D or the servo motor 26 are operated at the time of braking and starting to prevent skids. It has become. Each of the solenoid valves 7, 9, 15, 16, 7 ', 9', 1
Each of 5 ', 16', and 23 is switched to a position opposite to the illustrated state by energization (ON), and returns to the illustrated state when turned off.

That is, if the principle of skid prevention is explained, the pressure oil supplied from the master cylinder 3 is a normally open valve 7.15.
Brake calipers 4A to 4D via 7 'and 15' respectively
And a braking force is applied to the wheels by the brake calipers 4A to 4D. At this time, pressure control valves 14 are provided in the hydraulic systems toward the rear wheel caliper 4C and 4D, respectively, to limit the braking force on the rear wheel side. In response to the change, a large braking force is generated on the brake calipers 4A and 4B on the front wheel side where a larger load is applied. Further, a decrease in wheel peripheral speed due to braking is detected by each of the wheel speed sensors 6A to 6D, and based on this detection data, for example, when the speed suddenly decreases beyond a certain limit, the wheels tend to lock. The controller 27 determines that there is something. The controller 27 controls the normally-closed valves 9.9 ′, 16
・ By operating 16 ′, the hydraulic oil of the brake calipers 4A to 4D of the wheels determined to have a tendency to lock is supplied to the reservoir 11
・ Release to 11 'to reduce braking force. When the wheel peripheral speed is recovering, the normally closed valve that has been opened is closed to recover the braking force. In addition, reservoir 11 ・ 11 ′
Is returned to the master cylinder 3 side via the pressure oil pumps 12 and 12 'discharged to the master cylinder 3.

Next, the contents of the control executed by the controller 27 will be described in association with skid control operations during braking and acceleration.

Stup1: Wheel peripheral speed Rωi (where i = 1 to 4, i.e., 1 to 4; left front wheel, right front wheel, left rear Wheel and the right rear wheel).

Step 2: Differentiate the calculated Rωi with respect to time to calculate the Ri. Actually, the count value n at a certain time,
By dividing the difference between the count after the lapse of Δt and the value n + 1 by the Δt, an average value of the change rate within a certain time is obtained, and this average value is regarded as the change rate and used for the subsequent control.

Step3: Find the simulated vehicle speed Vref. In other words, to explain the concept of the simulated vehicle speed, during anti-skid braking, the wheel peripheral speed Rωi repeats ascending and descending and gradually descends while pulsing. Is given as the gradient of the tangent at a certain time. This gradient gradually increases as braking progresses, but never decelerates above 1g. Therefore, the rate of change (deceleration) of the change in the peripheral speed of the wheel is constant (usually -1 g).
When the vehicle approaches the gradient, a simulated vehicle speed Vref is obtained by setting a speed change when the vehicle is decelerated as it is at this gradient (normally, a tangent is drawn to the change curve at that time). Skid control is performed so as to approach Rωi.

Step4: The wheel peripheral speeds Rω3 to ₄ of the right and left rear wheels are compared with a value obtained by multiplying the simulated vehicle speed Vref by a constant coefficient (0.8 in the case of the embodiment) to determine the presence or absence of a skid. If the is skid, the process proceeds to Step 8 described later, otherwise, the process proceeds to Step 5.

Step5: If none of the rear wheels is skid, it is determined whether acceleration skid control is being performed for both front wheels. That is, FLAG1 and FLAG2 are “1” when skid control is performed on the left front wheel and the right front wheel, respectively.
(The process of setting these flags will be described later). If the mode is not the mode in which skid control is to be executed (FLAG1 = 0, FLAG2 = 0), Step 6 is executed.
Otherwise, proceed to Step 7.

Step 6: If the acceleration skid control is not being performed, the normally open valves 15 and 15 'of the hydraulic system of the rear wheels are turned off to make them in a normally open state.

Step 7: If the acceleration skid control is being performed, the normally closed valves 16 and 16 'of the rear wheel hydraulic system are turned off to be in a normally closed state, and then the process proceeds to Step 9 described later.

Step8: Close the normally open valves 15 and 15 'to reduce the braking force of the calipers 4C and 4D for both rear wheels, and close the normally closed valves 16
After opening 16 ', proceed to Step 9 described later.

Therefore, when one of the rear wheels is skidding during deceleration, the hydraulic pressure of the calipers 4C and 4D on the rear wheel side is reduced. In this case, considering that the rear wheel skid greatly affects the directional stability of the vehicle, the rear wheel caliper
A so-called arrow select in which a pressure control valve 14 is provided in the hydraulic system toward 4C and 4D so that the pressure is always lower than that of the front wheels. If none of the rear wheels is skid, it is determined whether or not the front wheels are under acceleration skid control, and if not under acceleration skid control, each of the valves 15 .15 ', 16.16' is OFF and maintained in the normal state regardless of the presence or absence of the control signal, and when under the acceleration skid control, the valves 16 and 16 'of the open system of the hydraulic system of the rear wheel OFF only with or without control signal
After maintaining the normal state, skid control CNTRL (Rω ₁ ) for one front wheel is executed, and Step 9 is executed.
Furthermore, skid control CNTRL for the other front wheel
(Rω ₂ ) Step 10 is executed.

Hereinafter, the contents of the control in the skid control CNTRL (Rω ₁ ) will be described with reference to FIG.

Step 11: It is determined whether or not traction (driving wheel skid phenomenon during acceleration) is occurring. That is, Rω
By ₁ ≧ 1.2Vref, it is determined whether the wheel peripheral speed Aruomega ₁ of one of the front wheels exceeds the simulated vehicle speed Vref somewhat higher, YE
In the case of S, proceed to Step 12, and in the case of NO, proceed to Step 13.

Step12: Skid (traction) control flow TRC (R
Go to ω ₁ ). (See FIG. 4) Step 13: It is determined whether skid (skid phenomenon at the time of deceleration) is occurring. That is, by Rω _{1 <0.8Vref,} determines whether the wheel speed Aruomega ₁ of one of the front wheels is below the simulated vehicle speed Vref certain degree, in the case of YES in Ste
Proceed to p14, and if NO, proceed to Step 15.

Step ₁₄ : Proceed to the anti-skid control flow ASC (Rω ₁ ). (See FIG. 5) Step 15: FLAG1 (see FIG. 4) indicating that one of the front wheels is under control is cleared because neither of the traction control and the anti-skit control is in the state.

Step16: Stop the engine output reduction command EG. That is, if one of the front wheels does not indicate skid, the engine output reduction command EG is issued based on the determination that even if the other front wheel is skid, skid can be prevented only with the braking force of the other wheel. Judging that output reduction is unnecessary,
The output of the engine output reduction command EG is stopped.

Step 17: It is determined whether or not FLAG2 is zero, that is, whether or not the other front wheel is in a traction control state. If it is under traction control (NO), proceed to Step 18, and If not (YES), S
Proceed to tep19.

Step 18: If the other front wheel is under traction control, turn on to open the normally closed valve 9 of the hydraulic pressure release system of one front wheel.

Step19: If the other front wheel is not under traction control, the normally open valve 15.1 provided in the hydraulic system to the rear wheel side
5 'and the switching valves 23 provided between the booster and the intake system are each turned off, so that the rear wheels can be braked by depressing a normal brake pedal.

Step 20: After turning off the normally open valve 7 and the normally closed valve 9 provided in the hydraulic system for one front wheel, the front wheels are braked by the hydraulic pressure from the master cylinder 3,
Returning to the flowchart of FIG.

Then, the traction control TRC described in Step 12 above
(Rω ₁ ) will be described.

Step21: Normally open valve 15.1 provided in the hydraulic system to the rear wheel side
5 'is turned on to switch to "closed", and the caliper 4C and 4D of the rear wheels are cut off from the hydraulic system so that the pressure fluctuation of the hydraulic system by the traction control does not affect the rear wheels.

Step22: FLAG1 indicating that the front wheels are under traction control
Set 1 to.

Step23: The wheel circumferential acceleration Ri of one front wheel is R
> 0, that is, whether traction is further progressing. If YES, proceed to Step 24; if NO, proceed to Step 25.

Step 24: When the vehicle is in the acceleration state, the valves 7 and 9 are turned off to allow the supply of hydraulic pressure to the brake calipers 4A and 4B of the left and right front wheels.

Step 25: When the vehicle is not in the acceleration state, the supply of the hydraulic pressure is shut off by turning on the valve 7, and the valve 9 is kept off to maintain the hydraulic pressure in the brake calipers 4A and 4B.

Step 26: Determine whether or not FLAG2 indicating that the other front wheel is in the traction control state is set to 1; YES
In the case of, the process proceeds to Step 27, and in the case of NO, the process proceeds to Step. Note that FLAG2 is established under the same conditions as in Step 22, in skid control performed for the other front wheel in the same manner as for the one front wheel.

Step 27: If the other front wheel is also in the traction control state, not only control the braking force but also judge that it is not possible to recover from the traction unless the engine output is reduced, and operate the auxiliary damper 24 by the servo motor 26. In order to reduce the engine output, an engine control signal EG is output to the motor control circuit 25.

Step 28: If the other front wheel is not in the traction control state, the valves 7 'and 9' are turned ON to reduce the hydraulic pressure in the brake caliper 4B of the other front wheel.

Step 29: Turn on the valve 23 to apply atmospheric pressure to the booster to increase the hydraulic pressure of the master cylinder.

FIG. 5 shows details of the anti-skid control performed in Step 14.

Step 30: The valve 23 is turned off, a negative pressure is applied to the booster, and a normal operation state for assisting the depression force of the brake pedal is kept.

Step 31: whether one of the front wheels is in a deceleration state, i.e., the wheel peripheral acceleration R ₁ is judged whether or not R _{1 <0,} to Step32 in the case of YES, i.e., if NO is to Step33 move on.

Step 32: When the vehicle is in the deceleration state, the valves 7 and 9 are turned on to reduce the hydraulic pressure in the brake caliper 4A.

Step 33: If the vehicle is not in the deceleration state, turn on the normally open valve 7 of the hydraulic pressure supply system to switch it to “closed”, and leave the normally closed valve 9 of the pressure reduction system OFF, and set the brake caliper 4A.
Hold the fluid pressure inside and wait for the skid to recover.

After the traction control (Step 21 to Step 29) or the anti-skid control (Step 30 to Step 33) for one of the front wheels is performed in Steps 11 to 20,
At ep10, skid control for the other front wheel is performed, and thereafter, the process returns to Step 1 and the same control is repeated.

Next, a specific example of skid (traction) control will be described with time with reference to FIG.

That is, this example shows the operation state of the brake when the vehicle starts in the state of LOμ with a small road surface friction coefficient and only one front wheel (left front wheel) is in the state of Hiμ.

At time t1, one of the front wheels has a skid tendency, and when the wheel peripheral speed of this wheel exceeds the simulated vehicle speed Vref by a certain amount or more,
When the valve 23 is turned on, a hydraulic pressure is generated from the master cylinder 3. At this time, since the valves 7 and 9 are both OFF, the hydraulic pressure of the brake caliper 4A of the one front wheel that tends to skid is increased by the operation of the master cylinder 3 to generate a braking force. However, since the valves 7 'and 9' are switched ON, the hydraulic pressure of the brake caliper 4B of the other front wheel does not increase. Further, since both valves 15 and 15 'are turned on and "closed", hydraulic pressure does not act on brake calipers 4C and 4D of both rear wheels.

At time t2, when it is detected that the other front wheel also has a tendency to skid, the valves 7 'and 9' are both turned off.
And the hydraulic pressure from the master cylinder is supplied to the brake caliper 4B of the other front wheel. Also, since both front wheels tend to skid (ie, FRAG1 = 1, FRAG2 =
2) It is determined that it is necessary to throttle the engine, the engine control signal EG is raised to ON, and the auxiliary damper 24 is turned in the closing direction.

At time t3, one of the front wheels enters a deceleration state (ie, R ₁ <0), so that the valve 7 is set to ON and the valve 9 is set to OFF to maintain the hydraulic pressure of the brake caliper 4A. Wait for recovery.

At time t4, the other front wheel also enters the deceleration state (that is, R ₂ <0), so that the valve 7 'is turned on and the valve 9' is turned off in order to maintain the hydraulic pressure of the brake caliper 4B. Wait for recovery.

At time t5, the peripheral speed Rω1 of _one front wheel becomes Vref × 1.
If it falls below 2, the valve 7
Turn 9 on. In addition, it is determined that there is no need to further reduce the engine output, and the engine control signal EG is stopped. Accordingly, the auxiliary damper 24 gradually rotates toward the horizontal posture and opens.

Oite the time t6, when the wheel peripheral speed Aruomega ₂ of the other front wheel becomes a predetermined value or less, both valves 7 ', 9' are connected together is switched to OFF to the master cylinder 3, The switching valve 23 is OFF As a result, the negative pressure of the intake system does not act on the booster 1, so that the master cylinder 3 operates only by the depression force of the brake pedal 2.
Therefore, when the brake pedal 2 is not depressed, the hydraulic pressure from the master cylinder 3 also decreases, and the pressure of the brake caliper 4B connected thereto also decreases. On the other hand, since the valves 15 and 15 'of the hydraulic system for the rear wheels are turned off, the hydraulic systems for the front wheels and the rear wheels are all in communication with the master cylinder 3. Even in the state of communication with the master cylinder 3, the hydraulic system of the rear wheels is maintained at a slightly lower pressure than the hydraulic system of the front wheels by the action of the pressure control valve 14.

Hereinafter, the same control as the above t _{1 to} s ₆ is performed at t ₇ to t ₁₂ and t ₁₃ to
By repeating the t _18, t ₁₉ ~t _23, left and right front wheels of the vehicle while the wheel peripheral speed Aruomega ₁ and Aruomega ₂ is brought close to the simulation vehicle speed Vref is gradually accelerated.

"Modified embodiment" a In the above-described embodiment, the case where the present invention is applied to the front wheel drive system is shown. However, the present invention can of course be applied to the rear wheel drive system. That is, based on the wheel peripheral speed data, the presence or absence of skid is detected for each of the two rear wheels. If only one of them is in the skid state, recovery from the skid is attempted only by adjusting the braking force, and both skids are recovered. When entering the state, adjustment of the engine output may be used together.

b In the above embodiment, the weight of the skid is determined based on whether one of the drive wheels is in the skid state or both are in the skid state. However, other means, for example,
The weight of the skid may be determined by determining how much the peripheral speed of the drive wheel is higher than the simulated vehicle speed, or by using this determination in combination with the determination of the one or both wheels. .

c In the above embodiment, the peripheral speed was measured for each wheel,
In addition, the case where the present invention is applied to a so-called four-sensor four-channel system having an independent braking hydraulic system is shown. However, it is possible to measure at least the driving wheel peripheral speed and determine the skid weight based on the measurement. The present invention can also be applied to a vehicle having a hydraulic system capable of controlling the braking force of the driving wheels separately from the driven wheels.

[Effects of the Invention] As is apparent from the above description, according to the present invention, the lightness of the skid state is determined based on the data obtained from the wheel speed sensors of the drive wheels. Is in a skid state, a hydraulic pressure is generated in the master cylinder, and a valve is operated to cut off the influence of the hydraulic pressure on the braking system of the driven wheel. Only by controlling the brake fluid pressure of the drive wheels
When the vehicle is in a severe skid state, the drive wheels are recovered from the skid by using both the control of the brake fluid pressure and the control of the engine output. In addition, the vehicle can be quickly and responsively accelerated.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a hydraulic system diagram of a control system constituting a skid control device, FIG. 2 is a flowchart of the entire control operation of a controller, and FIG. 3 is a skid of a front wheel. FIG. 4 is a flowchart of the traction control, FIG. 5 is a flowchart of the anti-skid control, and FIG. 6 is an output state of the control signals of the solenoid valve and the engine when the vehicle starts, the brake fluid pressure, and the accelerator opening. 6 is a timing chart showing the correspondence between the degree, the simulated vehicle speed and the wheel peripheral speed over time. 1 ... booster, 2 ... brake pedal, 3 ... master cylinder, 4A, 4B, 4C, 4D ... brake caliper, 6A
・ 6B ・ 6C ・ 6D …… wheel speed sensor, 7.7 ′ ・ 15 ・ 15 ′…
... normally open solenoid valve, 9.9 ', 16, 16' ... normally closed solenoid valve, 20 ... intake line, 21 ... accelerator pedal, 22 ... main intake damper, 23 ... switching valve, 24 ... auxiliary Damper, 25 ... Motor control circuit, 27 ... Controller.

Claims (1)

(57) [Claims] 1. Wheel speed detecting means provided at least on driving wheels for respectively measuring wheel peripheral speeds, estimating means for estimating vehicle speed from detection data of the wheel speed detecting means, and detection data of the wheel speed detecting means Calculating means for calculating the wheel acceleration from the vehicle, a hydraulic system for transmitting hydraulic pressure generated from the master cylinder to the brake calipers of the driving wheels and driven wheels, a valve for opening and closing the hydraulic system toward the driving wheels, A valve for opening and closing a hydraulic system directed to a driving wheel, a booster for generating hydraulic pressure in the master cylinder by receiving a supply of operating pressure based on operation of a brake pedal, and a brake pedal provided in the booster. A switching valve for supplying an operating pressure to the booster independently of operation, an auxiliary accelerator provided in the intake system of the engine for limiting an intake flow rate, and operating the auxiliary accelerator Control circuit and said hydraulic system and each provided with a valve to the negative pressure system for adjusting the intake air flow rate Te,
And a controller for controlling a control circuit of the auxiliary accelerator, the controller determines the degree of skid state of both drive wheels from the wheel peripheral speed and acceleration of both drive wheels and the estimated vehicle speed, Regardless of the degree of skid, the switching valve is operated to apply operating pressure to the booster to supply hydraulic pressure to the braking hydraulic system of the skid drive wheel to perform braking, and Skid control wherein the valve is operated to disconnect the brake hydraulic system from the brake hydraulic system to the driving wheels, while the auxiliary accelerator restricts the intake flow rate when the skid advances beyond a certain limit. apparatus.