JPS62203863A - Antiskid control device for vehicle - Google Patents

Abstract

PURPOSE:To maintain the running performance of a vehicle while eliminating a slip at one wheel, by delivering a control signal to a brake means, preferentially to the output control of an engine by a skid control means so that the one wheel is braked. CONSTITUTION:A control unit 20 receives signals Vr, Vl, Vor, Vol from speed sensors 21-24 for detecting the speeds of wheels 2-5, and also receives a throttle opening degree signal TA, an engine rotational speed signal Ne, a gear position signal GP and accelerator signal Aa. The unit 20 determines whether the vehicle is in a starting acceleration condition or a steady-state running condition, in accordance with the vehicle speed, and delivers a drive signal to an actuator 30 or 31 for left or right drive wheel 2, 3, which has a larger slip ratio than other, in order to brake it when when the difference between the slip rates of the left and right device wheels 2, 3 exceeds a predetermined value, thereby it is possible to make both slip rates equal to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides skid control that eliminates the occurrence of slip by selectively controlling engine output or braking force according to the slip state of drive wheels. This invention relates to a skid control device for an automobile.

(Prior art) Conventionally, skid control (or traction control), which controls the rotational speed of the driving wheels of an automobile, has been used to control the rotational speed difference between the driving wheels and the driven wheels, as seen in Jibun No. 59-202963. A known technique is to reduce the torque transmitted to the driving wheels by controlling a clutch or accelerator when slipping exceeds a set value, thereby eliminating the slipping of the driving wheels.

The above-mentioned skid control can separate the driving force from the accelerator operation of the driving sound according to the driving condition of the car, and control it so that the optimum driving condition can be obtained in response to the accelerator operation amount. In particular, when the engine drive force is large and slip occurs due to slippery road conditions, the drive force is reduced to suppress the slip.

However, when the left and right drive wheels have different road surface conditions, for example, when one drive wheel is running on a paved road surface and the other drive wheel is running on a sandy road surface, only the other drive wheel is likely to slip. The slip rate on this driving wheel side becomes greater than the slip rate on one of the driving wheels. Then, based on the detection of the slip state, skid control is performed in the direction of reducing engine output, but the reduction in engine output is dominated by the elimination of the slip state of the drive wheel with a large slip ratio. This results in a significant drop in engine output, making it difficult to obtain good driving performance.

(Object of the Invention) In view of the above circumstances, the present invention performs skid control according to the occurrence of slip, and eliminates the slip state without reducing engine output when the slip states of the left and right drive wheels are significantly different. It is an object of the present invention to provide a skid control device for an automobile as described above.

(Structure of the Invention) The skid control device of the present invention includes a skid control means that controls engine output according to the slip state of the drive wheels, a brake means that can independently brake the left and right drive wheels, and a skid control device that controls the engine output according to the slip state of the drive wheels. a slip state detection means for detecting a rotation difference between the left and right drive wheels; and a slip state detection means that receives a signal from the slip state detection means and gives priority to engine output control by the skid control means when a slip occurs where the rotation difference between the left and right drive wheels exceeds a predetermined value. The invention is characterized in that it includes a brake drive means for braking one of the drive wheels by outputting a control signal to the brake means.

FIG. 1 is an overall configuration diagram for clearly showing the configuration of the present invention. For a car 1, right and left driving wheels 2, 3 and driven wheels 4, 5
A slip state detection means 7 detects the slip state of the drive wheels 2 and 3 from the rotation difference between the drive wheels 2 and 3 or the rotational acceleration of the drive wheels 2 and 3, and also detects the rotation difference between the right and left drive wheels 2 and 3.
A skid control means 8 is provided which receives the signal from the slip state detection means 7 and controls the engine output so that the slip is in the optimum state by adjusting the throttle opening of the engine 6 when slip occurs. There is.

A brake means 9 is provided which can independently control the braking force of each of the right and left drive wheels 2.3, and a brake drive signal is output from the brake drive means 10 to the brake means 9. The drive means 10 outputs a signal corresponding to the rotation difference between the right and left drive wheels 2.3 from the slip state detection means 7, and when a slip occurs in which the rotation difference between the right and left drive wheels 2.3 exceeds a predetermined value, the Priority is given to engine output control by the skid control means 8, and a control signal is output to the brake means 9 to brake the driving wheel 2 or 3 where a large slip has occurred, and the right and left driving wheels 2.3
This reduces the rotational difference between the two and eliminates the slip condition.

After the rotation difference between the right and left drive wheels 2 and 3 is eliminated by the brake means 9, skid control is performed by the engine output control by the skid control means 8 in response to the occurrence of slip from this state to control the optimum slip state E. It is something that can be written.

(Effects of the Invention) According to the present invention, in skid control in which the engine output is controlled by the skid control means, when a one-wheel slip state occurs in which the rotation difference between the right and left drive wheels exceeds a predetermined value, the skid control means By giving priority to engine output control, the drive wheel on the side where a large slip is occurring is braked to reduce the rotational difference and converge the slip, resulting in a reduction in engine output. It is possible to eliminate one-wheel slip while maintaining good running performance and obtain greater driving force.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 is an overall configuration diagram of a specific example.

The automobile 1 includes right and left driving wheels 2.3 and driven wheels 4.5, and the driving force of the engine 6 is transmitted to the driving wheels 2 and 3 via a propeller shaft 15 and a drive shaft 16.

The driving force of the engine 6 is controlled by the operation of a throttle motor 18 that adjusts the opening degree of a throttle valve 17. A control signal from a control unit 20 is output to the throttle motor 18 to control its operation, that is, the engine output. In addition, the right and left drive wheels 2 and 3
An actuator 30.31 that independently operates the brake mechanism to generate braking force is provided, and a control signal from the control unit 20 is output to this actuator 30.31 to control its operation, that is, the braking force. .

The control unit 20 is installed for the right and left driving wheels 2.3 and driven wheels 4.5 in order to detect the slip state of the driving wheels 2. Speed sensors 21 to 24 that detect vehicle speed)
Each rotational speed signal Vr, Vl, Vor,
Each Vol is input.

Further, in order to detect the operating state of the engine 6, a throttle sensor 25 that detects the opening degree of the throttle valve 17 is provided.
Throttle opening signal TA from , engine rotation speed signal Ne from rotation speed sensor 26 that detects engine rotation speed,
Gear A7 position sensor 2 that detects the gear shift position of the transmission
Gear position purchase Q from 7 C1, P1 accelerator pedal 28
An accelerator signal Δa from an accelerator sensor 29 that detects the maximum operation is input to the control unit 20, respectively.

The control unit 2o has the functions of each means shown in FIG. 1, and determines whether the vehicle is in a starting acceleration state or a steady running state based on the vehicle speed, and in the starting acceleration state, the drive wheels 2.
When the occurrence of slip is detected from the acceleration of 3, it is confirmed that the rotation difference between the right and left drive wheels 2.3 is smaller than a predetermined value, and the throttle opening is reduced to eliminate the occurrence of slip. When deceleration is not occurring, skid control is performed to maintain the throttle opening while increasing the throttle opening to maintain a substantially constant slip state. Also, when transitioning to steady driving, the left and right drive wheels 2
After confirming that the rotation difference between , 3 and 3 is smaller than the predetermined value,
The right and left average speeds of the driving wheels 2 and 3 and the right and left average speeds of the driven wheels 4.5 are determined, and the slip ratio is determined based on the difference between the two.
A control signal is output to the throttle motor 18 of the engine 6 to skid control the driving force so that this slip ratio falls within the optimum range.

On the other hand, when the difference in rotation between the right and left drive wheels 2 and 3, that is, the difference in slip ratio, increases beyond a predetermined value, a drive signal is output to the actuator 30 or 31 for the brake mechanism of the drive wheel 2 or 3 with the larger slip ratio. The system applies braking force to the vehicle and performs brake control so that the slip ratios on both sides are equal.

The operation of the control unit 20 will be explained based on the flowchart shown in FIG. After the start, step S
1, the output signals of the various sensors are read respectively. Then, in step S2, the average speed ■ of the right and left driving wheels 2 and 3 is determined, and in step S3, the average speed Vo of the right and left driven wheels 4 and 5 is similarly determined. The slip rate S of the driving wheels 2 and 3 is calculated, and in step S5, the slip rate S of the driving wheels 2 and 3 on the right side is calculated.
The right side slip rate 3r is determined from the speed difference between the left side slip rate 3r and the left side slip rate S1 from the speed difference between the left driving wheel 3 and the driven wheel 5. Furthermore, in step S6, the acceleration a (deceleration b=-a) of the driving wheel 2.degree. 3 is calculated.

In step S7, it is determined whether or not the driven wheel average speed VO, that is, the vehicle speed, is less than the set value ■1. If YES is less than the set value ■1, it is determined that the vehicle is in a starting acceleration state, and the process proceeds to step S8. , the acceleration of the driving wheels 2°3 ri! a is set value 8
Determine whether it is 1 or more.

If this determination is YES and the acceleration a is equal to or higher than the set value 81 and a slip equal to or higher than the predetermined value has occurred, the difference between the slip rates Sr and St of the right and left drive wheels 2.3 reaches the predetermined value K in step S9. It is determined whether or not the vehicle is in a one-wheel slip condition. The predetermined value is set to a value that is larger than the difference in slip ratio that does not depend on the difference in right and left road surface conditions such as cornering.

If the determination in step S9 is No and there is no one-wheel slip state, the process proceeds to step 814, where a control signal for reducing the throttle opening by a predetermined value is output to the throttle motor 18 to reduce the throttle opening. And step 315
Determine whether the acceleration a has become less than the set value 81,
When NO, the throttle opening degree is reduced until the slip is resolved.

If the determination in step S15 is YES and the occurrence of slip has been resolved, it is determined in step 516 whether or not the accelerator signal is in the off state, and if the accelerator is in the off state, the control is ended. On the other hand, if the determination in step 816 is No and the accelerator is in the operated state, the throttle opening is held in step S17, and it is determined in step 818 whether or not a deceleration of a predetermined value b1 or more is occurring. do. In the case of No, in which a deceleration equal to or greater than the predetermined value b1 has not occurred, the throttle opening is continued to be held for a predetermined time T in step 819, and then the throttle opening is corrected in the increasing direction in step S20. On the other hand, if Y[ES indicates that a deceleration equal to or greater than the predetermined value b1 has occurred, the process proceeds to step 820 and immediately increases the throttle opening.

On the other hand, if the Stellar 189 judgment is YES, the left and right driving wheels 2.
3, if there is a difference in the slip ratios greater than or equal to a predetermined value, it is determined in step 810 whether the slip ratio S1 on the left side is larger than the slip ratio Sr on the right side. This judgment is YES
When the slip rate S1 on the left side is large in step S, step S
In Step 11, a drive signal to be output to the actuator 31 of the left drive wheel 3 is set so that both slip ratios are equal, and in Step 813, a brake drive signal is output to the actuator 31 based on this signal to perform braking. Make the slip ratios equal. Also, the determination in step S10 is NO.
When the slip rate S on the right side is large, step 81
In step S13, the drive signal to be output to the actuator 30 of the right drive wheel 2 is determined so that both slip ratios are equal, and in step S13, a brake drive signal is similarly output.

Next, if the determination in step S7 is No and the vehicle speed Vo exceeds the set value v1 in a steady running state, the process proceeds to step S21 and the acceleration a of the driving wheels 2 and 3 is set to 81.
Determine whether or not the value is greater than or equal to the value. If this determination is YES and the acceleration a is equal to or higher than the set value 81 and a slip equal to or higher than the predetermined value has occurred, step S22 determines that the difference between the slip rates Sr and 81 of the right and left drive wheels 2 and 3 exceeds the predetermined value K. It is determined whether or not the vehicle is in a one-wheel slip condition.

If the determination in step S22 is YES, the right and left drive wheels 2,
If there is a difference in the slip ratios of 3 and 3 by a predetermined value of 1it K or more, it is determined in step 823 whether the slip ratio S1 on the left side is larger than the slip ratio 3r on the right side. If this determination is YES and the left slip ratio S1 is large, a drive signal to be output to the actuator 31 of the left drive wheel 3 is set in step 824 so that both slip ratios are equal, and in step 826 the actuator is outputted based on this signal. A brake drive signal is output to 31 to perform braking and equalize the right and left slip ratios. Further, if the determination in step S23 is No and the right slip ratio 3r is large, the drive signal to be output to the actuator 30 of the right drive wheel 2 is set in step 825 so that both slip ratios are equal, and the same is done in step 326. Outputs brake drive signal.

On the other hand, when the determination in step 821 is No, it is determined in step S27 whether or not the slip ratio S exceeds the first set value S1.

If the determination in step 827 is YES and the slip ratio S exceeds the first set value SL, step 828
A control ll signal for reducing the throttle opening by a predetermined value is output to the throttle motor 18 to reduce the throttle opening. Then, in step S29, it is determined whether the slip rate S has become less than the second set value 82. If NO, the throttle opening degree is reduced in step S28 until the slip is eliminated.

If the determination in step S29 is YES and the slip ratio S becomes less than the second set value 82, step S29
0, the throttle opening is increased, and by repeating the above operation, skid control is performed by feedback control so that the slip ratio S falls within a predetermined range.

According to the above embodiment, although skid control is performed in which the throttle opening is adjusted and the slip rate S is feedback-controlled to an optimum range, when one wheel slips, brake control is given priority over adjusting the engine output. After performing this to equalize the slip ratios on both sides, Sugirad i and I+ 60 are performed based on the detection of the slip state.

J3, in the above embodiment, the detection accuracy of the slip state is improved by changing the detection method for the slip state during starting acceleration and during steady running, that is, at low speed and high speed, but the detection accuracy is improved by changing the detection method for the entire range. The control may be based on the detection method. Further, the driving force may be controlled by controlling various engine output adjusting means in addition to adjusting the throttle distance.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram for clearly showing the configuration of the present invention, FIG. 2 is an overall configuration diagram of a specific example, and FIG. 3 is a flow chart diagram for explaining the operation of the control unit. 1...Car 2,3...
Drive wheel 4.5... Driven wheel 6...
・Engine 7... Slip state detection means 8... Sugirad control means 9... Brake means 10... Brake drive means 17... Throttle Valve 18...Throttle motor 20...Control unit 21-24...
...Speed sensor 30.31...Actuator Fig. 1 Fig. 2

Claims (1)

[Claims] (1) A skid control device for an automobile, comprising a skid control means for controlling engine output according to the slip state of the drive wheels, and a brake means capable of braking the left and right drive wheels independently; and a slip state detection means for detecting a rotation difference between the left and right drive wheels, and upon receiving a signal from the slip state detection means, priority is given to engine output control by the skid control means when a slip occurs where the rotation difference between the left and right drive wheels exceeds a predetermined value. 1. A skid control device for an automobile, comprising: brake drive means for braking one drive wheel by outputting a control signal to the brake means.