JPS62279157A - Antiskid control method - Google Patents

Abstract

PURPOSE:To simultaneously improve both brake performance and maneuvering stability, by a method wherein, in a rotation state in that, when a steering angle is high, wheels are hard to lock, control of a brake force is started. CONSTITUTION:A control device 4 compares a change in the value of a wheel speed with a condition stored by a computer to decide whether a wheel is about to be locked, and when the wheel is about to be locked, a brake oil pressure is reduced. When a speed is restored, an instruction on boost is outputted to an actuator. In the control device 4, from a signal from a steering sesnor 5, it is decided whether the steering angle of a handle exceeds theta deg.. In case the steering angle is below theta deg., when deceleration, computed from a wheel speed inputted from a wheel speed sensor 5, exceeds a given value X, the control device is shifted to control routine. In the case of the steerign angle exceeding theta deg., when deceleration exceeds X- X lower than a given value, the control device is shifted to control routine.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) The present invention is based on I! ! Equipped with an anti-skid feature that prevents the vehicle from skidding due to the wheels being jammed when braking! This relates to a control method.

(Conventional technology) Applying braking on slippery roads such as rain-covered roads.
If you apply sudden braking even on a normal road surface, the wheels will lock, and in this state the wheels will slip, causing the coefficient of friction between the Q wheels and the road surface to drop rapidly, resulting in the vehicle body being deflected by some disturbance. This results in a so-called skid. In particular, if only the rear wheels were locked, the vehicle could spin, which was very dangerous. However, during braking, the center of gravity moves forward and the load applied to the rear wheels decreases, which reduces the adhesion between the rear wheels and the road surface, making them more likely to lock.

In order to prevent this, conventionally known systems have installed probosciconing valves, etc., so that when the braking force exceeds a certain level, the rate of increase in braking force on the rear wheel becomes smaller than that on the front single wheel. It is being

In other words, by supplying the master cylinder's hydraulic pressure directly to the front wheel cylinder, and by supplying hydraulic pressure to the rear wheel cylinder through the provisioning valve, the increase rate of the master cylinder's hydraulic pressure can be increased. A system is known in which hydraulic pressure is supplied at a smaller rate of increase than the previous one.

Furthermore, control! I! Front and rear wheels at J1 or 4
There is also known a system that detects the rotational state of two wheels and automatically relieves the braking oil pressure before each rIL wheel becomes locked, thereby preventing the wheels from locking. For example, in Japanese Utility Model Application Publication No. 60-29762, the rotational state of the rear wheels is detected, and the power hydraulic pressure generated by the engine-driven hydraulic pump is regulated to a value corresponding to the hydraulic pressure of the master cylinder using a regulator valve. This power oil pressure and the master shilling oil pressure are supplied to the 7 actuator, and in this actuator, the feed valve is controlled by a humpiator control device to which the rotational state of the rear wheel is input, and the feed valve is controlled via the feed valve. A system has been disclosed in which the brake hydraulic pressure for the rear wheels is controlled in accordance with the rotational state of the rear wheels by supplying power hydraulic pressure to a brake hydraulic pressure adjusting piston.

Similarly, as shown in FIGS. 3 and 4, each wheel 1
1 is detected by the wheel speed sensor 12 and inputted to the computer control device 13, and the hydraulic pressure from the master cylinder 14 is sent to each l1IW! 1
A hydraulic pump 18 of the power unit 17 is supplied to the wheel cylinder 16 of the power unit 15 for the actuator 15.
The supply valve 1 is controlled by the control device 13 so that the hydraulic pressure from the
9 and exhaust valve 20, and the control device 13 controls the wheel 11 based on the speed and deceleration of the wheel 11.
Determine the possibility of locking the supply valve 19, if necessary.
There is also known a system in which the actuator 15 is actuated by the discharge valve 20 to relieve the braking oil pressure to prevent locking.

(Problems to be Solved by the Invention) As described above, in conventional anti-skid control, control is performed by taking in only the rotational state of the wheels as information. However, there is a problem in that it is difficult to achieve both braking performance and handling stability using only this method, and one of the performance must be sacrificed. In other words, in order to improve braking performance, if the braking oil pressure is set not to be relaxed until the wheels have almost stopped rotating, there is a risk of skidding when the steering angle of the steering wheel is large, such as when turning. (Kaa'), fi longitudinal stability is sacrificed. Conversely, if the brake hydraulic pressure is relaxed from a state in which the wheels are difficult to lock in order to prevent this, there is a problem in that the braking performance deteriorates.

The present invention aims to solve the above-mentioned problems.

(Means for solving problems).

The anti-skid control method of the present invention includes a steering angle is detected, and if the steering angle is large, control of the braking force is started in a rotating state in which the wheels are less likely to be locked.

(Function) Since the present invention has the above-described configuration, anti-skid control can be performed by incorporating not only the rotational state of the wheels but also the steering angle of the steering wheel as information. In other words, when the steering angle of the steering wheel is less than a certain angle, the braking method is used to ensure braking performance, and when the steering angle of the steering wheel is above a certain angle, the braking force is relaxed to improve turning performance in a state where the wheels are less likely to lock. It is possible to use a control method that ensures steering stability such as the above, and it is possible to achieve both braking performance and steering stability.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

In Figure 1, la and lb are self! I! front wheel of lj car,
Rear wheels 2a and 21r are each provided with a wheel speed sensor 3 for detecting the rotation of the wheels, and their detection signals are input to the computer control device 4, respectively. Further, the steering angle of the steering wheel is inputted to the control device 4 from the steering angle sensor 5.

The control II signal output from the control device 4 is inputted to the supply valve and discharge valve of the actuator to control the braking oil pressure from the master cylinder, as in the conventional example shown in FIGS. 3 and 4. 6 to feed the wheel shillings of each wheel! has been completed. Note that the configuration of the actuator and the like is similar to that shown in FIGS. 3 and 4, and detailed explanation thereof will be omitted.

As a basic control routine, the control device 4 receives J1! from the detection signal of the wheel speed sensor as in the conventional case. The wheel speed is calculated, and the change in value is compared with the conditions stored in the combiator to determine whether the wheels are about to lock up. If the wheels are about to lock up, the brake hydraulic pressure is reduced, and when the speed recovers, it is increased. The actuator is equipped with a control routine that sends a command to the actuator to press the actuator. Furthermore, this i control device 4
, it is determined from the signal from the steering angle sensor 5 whether the steering angle of the steering wheel is greater than or equal to θ°, and if θ° is not the threshold, the deceleration calculated from the wheel speed input from the wheel speed sensor 5 is set to a predetermined value. When the steering angle is greater than or equal to .

Next, the operation will be explained with reference to FIG. 2. When braking is started and the brake switch is turned on, the steering angle first changes to θ based on the signal from the steering angle sensor 5.

Decide if the above is true. When the steering angle is less than θ° and the vehicle is in a straight-line state, the deceleration of each wheel is calculated based on the signal from the wheel speed sensor 5 to a predetermined value stored in advance. Determine whether it is greater than or equal to X. If the deceleration is greater than or equal to X, the routine shifts to a control routine that controls the braking oil pressure to the wheel sills in accordance with the wheel speed. If it is less than the predetermined value X, the normal braking state is maintained and the process returns to the determination of the steering angle. On the other hand, when the steering angle is θ° or more and the vehicle is turning, it is determined whether the deceleration of the wheels is equal to or greater than a predetermined value X−ΔX, which is smaller than that when the vehicle is traveling straight. If the deceleration is equal to or higher than X-ΔX, the control routine shifts to a control routine that controls the braking oil pressure to the wheel sill according to the wheel speed in the same way as above, and if it is less than the predetermined value X-ΔX, the normal braking state is resumed. The steering angle is maintained and the process returns to the determination of the steering angle. In this way, when turning, the control routine is entered with a smaller deceleration and the braking oil pressure is relaxed according to the speed of the wheels, thereby reliably preventing the wheels from locking during turns and improving steering stability. It is possible to ensure gender.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with various modifications. For example, in the above embodiment, each of the four wheels is controlled separately, but even if the front wheels are controlled separately and the rear wheels are controlled simultaneously, the rear wheels may be controlled independently. It may also be possible to control only the In addition, although we have shown an example in which the steering angle and wheel deceleration are used to determine whether or not to proceed to the ill 13 $1 routine, the speed of the wheels may also be added to the determining factors, and furthermore, the control routine may proceed. It is also possible to set the male control condition itself in the control routine depending on the steering angle, rather than depending on whether or not the steering angle is used.

(Effects of the Invention) According to the anti-skindo control method of the present invention, the steering angle is detected, and when the steering angle is large, the control of the braking force is started in the turning state where the wheels are less likely to lock. Therefore, when the steering angle of the steering wheel is less than a certain angle, ♂II! I! /J A braking method that secures performance, and when the steering angle of the steering wheel is above a certain angle, the wheels are less likely to lock, and the braking force is summed with Ifc to ensure steering stability such as FE rotation. This method has the effect of achieving both braking performance and steering stability.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1 is a schematic diagram of the main part, FIG. 2 is a 70-chart of the main part of the control process, and FIGS. 3 and 4 1± Show the conventional example, ? 143
The figure is a schematic diagram of the groove structure, and Figure 4 is a diagram of the main part of the structure. 3...Wheel speed sensor 4...
・・・・・・・・・制御装置５・・・・・・・・・・・・蛇角センサー代理人 弁理士 石 原 勝第１図第４図

Claims (1)

[Claims] (1) In an anti-skid control method that prevents the wheels from locking and the vehicle body from skidding by controlling the braking force on the wheels according to the rotational state of the wheels during braking, the steering angle is detected and the steering angle is An anti-skid control method characterized in that, when the angle is large, control of the braking force is started in a rotating state in which the wheels are less likely to be locked.