JPS62203939A - Skid controller for automobile - Google Patents

Abstract

PURPOSE:To improve responsiveness on the early time of the occurrence of slips, by setting the controlled variable of a skid controlling means for a controlled variable holding down the output of an engine at a prescribed ratio based on the signal of a slip detecting means on the early time of the starting of slips. CONSTITUTION:A slip detecting means 7 for detecting the slip condition of driving wheels 2, 3 from the rotational difference between the driving wheels 2, 3 and driven wheels 4, 5 or the rotational acceleration of the driving wheels 2, 3 or the like is provided for an automobile 1. And a skid controlling means 8 which receives the signal of the means 7, adjusts the opening of the throttle of an engine 6 and the like on the occurrence of slips, and controls driving force for making the slips for the most favorable condition is provided. In this case, an early time cotrolled variable setting means 9 for setting up the controlled variable of the early time of the starting of slips is provided for the means 8. And on the early time of the starting of slips, the controlled variable of the means 8 is set for a controlled variable controlling the output of the engine at a prescribed ratio being based on the signal of the means 7. After that, regular skid control is carried out so as to control the output of the engine most suitably.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a skid control device for an automobile that performs skid control that controls driving force according to the slip state of drive wheels.

(Prior art) Conventionally, skid control (or traction control) for controlling the rotational speed of the driving wheels of automobiles has been proposed in Japanese Patent Laid-Open No. 5
As seen in No. 9-202963, when the rotation difference between the driving wheel and the driven wheel exceeds the set value and slip occurs,
A known technique is to reduce the torque transmitted to the drive wheels by controlling a clutch or an accelerator to eliminate slip of the drive wheels.

Skid control as described above separates the driving force from the driver's accelerator operation according to the driving condition of the vehicle, and controls the vehicle so that the optimum driving condition can be obtained in response to the amount of accelerator operation. In particular, when the engine driving force is large and slipping occurs due to slippery road conditions, the driving force is reduced to suppress the slipping.

For example, if the driver is driving with the accelerator fully depressed to obtain the maximum output at each rotational speed, and the first slip condition occurs where skid control is performed, the throttle is opened in the direction of reducing the engine output. In this skid control, the throttle opening degree is gradually closed from a fully open state, and the throttle opening degree is controlled to maintain a predetermined slip state, that is, the engine output. In this way, in the early stages of slippage, the optimal state of engine output corresponding to road surface conditions etc. cannot be determined, and the speed of change to perform skid control to a predetermined output characteristic while detecting slippage is slow. It takes time to reach the optimal state, which becomes an obstacle when trying to improve responsiveness.

In other words, slip is likely to occur when the engine is operated at full throttle, and when this slip starts to occur, the slip rate increases rapidly, so the engine is driven at a predetermined reduction rate as slip occurs. If you perform skid control that reduces the force, determines whether the slip has decreased in the reduced state, and further reduces the driving force, the degree of change in the driving force is small, and when skid control is started, the skid control is large. A slip will occur. On the other hand, if the degree of change in the driving force is increased, the convergence when slip occurs is improved, but the control stability of the driving force in the optimum slip state is reduced.

(Object of the Invention) In view of the above-mentioned circumstances, an object of the present invention is to provide an automobile skid control device that improves the responsiveness at the initial stage of slip occurrence when performing skid control according to the occurrence of slip. It is something.

(Structure of the Invention) A skid control device of the present invention includes a slip detection means for detecting a slip state of a drive wheel, a skid control means for controlling a driving force according to the slip state, and a skid control device for detecting a slip state based on a signal from the slip detection means. The present invention is characterized by comprising an initial control amount setting means for setting the control m of the skid control means to a control amount that suppresses the engine output at a predetermined ratio at an initial stage of start.

FIG. 1 is an overall configuration diagram for clearly showing the configuration of the present invention. The automobile 1 is provided with a slip detection means 7 for detecting the slip state of the driving wheels 2.3 from the rotational difference between the driving wheels 2, 3 and the driven wheels 4.5 or the rotational acceleration of the driving wheels 2.3. A skid control means 8 is provided which receives a signal from the slip detection means 7 and controls the driving force so that the slip is in an optimum state by adjusting the throttle opening of the engine 6 when a slip occurs.

Initial control amount setting means 9 sets control l1ffl at the initial stage of slip start for the skid control means 8.
is installed. This initial control M setting means 9 is a control port that controls the control amount of the skid control amount stage 8 to suppress the engine output at a predetermined ratio (for example, 80%) at the initial stage of slip start based on the signal of the slip detection means 7. When a slip occurs, the engine is first controlled to this initial setting, and then normal skid control is performed from this state to control the engine output to the optimum state.

(Effects of the Invention) According to the present invention, in skid control using the skid control amount &, when a slip occurs, the engine output is first reduced by a predetermined ratio and the output fluctuation speed is increased, thereby reducing the slippage at the initial stage of the slip. It is possible to perform suppression control in a short time and with good responsiveness, and from this state, skid control can be performed depending on the state of occurrence of slip, thereby making it possible to suppress the occurrence of slip at an early stage and obtain a larger 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 drive shafts 2.3 and driven wheels 4.5, and the driving force of the engine 6 is transmitted to the drive wheels 2 and 3 via a propeller shaft 15; P3 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.

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,
Vol is inputting it.

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 , and engine rotation speed signal Ne1 from the rotation speed sensor 26 that detects the engine rotation speed.
Gear position sensor 27 that detects the gear shift position
gear position signal GP from , and accelerator signal Aa from accelerator sensor 29 that detects the operation port of accelerator pedal 28
are respectively input to the control unit 20.

Then, the control unit 20 controls the 'first
It has the functions of each means shown in the figure, and determines whether it is a starting acceleration state or a steady running state from the vehicle speed, and in the starting acceleration state, the driving wheel 2
When the occurrence of slip is detected from the acceleration of , 3, the throttle opening is set to a predetermined value that reduces the engine output at a predetermined ratio, and a control signal is output to the throttle motor 18 of the engine 6 to reduce the driving force, This is to eliminate the occurrence of slippage, and this throttle opening is maintained during periods where no large deceleration occurs. On the other hand, when shifting to steady running, 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 a slip rate is determined based on the difference between the two, and this slip rate is set within the optimal range. A control signal is output to the throttle motor 18 of the engine 6 to skid control the driving force.

The basic operation of the control unit 20 will be explained based on the flowchart shown in FIG. After starting, the output signals of the various sensors are read in step S1. Then, in step S2, the average speed V of the right and left driving wheels 2 and 3 is determined, and in step S3, the average speed V 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 in step S4 based on the difference V - V a between both average speeds.

Furthermore, in step S5, the acceleration a (deceleration b=-a) of the drive wheel 2.3 is calculated.

In step S6, it is determined whether the driven wheel average speed ■0, that is, the vehicle speed, is less than the set value V1.If YES, which is less than the set value v1, it is determined that the starting acceleration state is reached, and the process proceeds to step S7, in which the driving wheel It is determined whether the acceleration a of 2°3 is greater than or equal to the set value 81.

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 throttle opening TA is set to a predetermined value TAO (initial throttle opening) in step S8, and step S9 A control signal corresponding to this opening degree is output to the throttle motor 18 to reduce the throttle opening degree to the above set value TAo at once. Then, in step S10, it is determined whether the acceleration a has become less than the set value 81, and if the answer is No, the throttle opening degree is reduced until the slip is eliminated.

If the determination in step SIO is YES and the occurrence of slip is eliminated, it is determined in step 811 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 811 is NO and the accelerator is in the operated state, the throttle opening is held in step S12, and the predetermined value 1)tf;1 is determined in step 813.
．． It is determined whether the above deceleration is occurring. 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 814, and then the throttle opening is corrected in the increasing direction in step 815. On the other hand, if the answer is YES, indicating that a deceleration greater than or equal to the predetermined value b1 has occurred, step 81.5
The throttle opening degree is increased immediately after proceeding to the step.

Next, if the determination in step S6 is No and in a steady running state where the vehicle speed 0 exceeds the set value V1, it is determined in step S16 whether or not the slip ratio S exceeds the first set value Sl. It is something to do. If the determination in step S16 is YES and the slip ratio S exceeds the first set value S1, the throttle opening degree TA is changed in step S17.
is set to a predetermined value TAo, and in step 818, a control signal corresponding to this opening degree is output to the thrower 1 helm motor 18 to reduce the throttle opening degree to the above-mentioned set value TAO at once. Then, in step 819, it is determined whether the slip rate S has become less than the second set value 82, and if the answer is No, the throttle opening degree is reduced until the slip is eliminated.

If the determination in step 819 is YES and the slip ratio S becomes less than the second set value 82, step 81
Proceeding to step 5, the throttle opening degree is increased, and by repeating the above operations, skid control is performed by feedback control so that the slip ratio S falls within a predetermined range.

The throttle opening degree TAo set in step S8 and step 817 is the one set in control 4 at the start of slip. As shown in Fig. 4, in the output characteristics with respect to the throttle opening TA at each engine speed NO, the throttle opening Pl, P2, etc. at which the engine output is reduced to a certain ratio (for example, 80%) are determined, and based on this, Then, as shown in FIG. 5, a curve P is set in which the engine output is at a predetermined ratio with respect to the engine speed Ne, and the above-mentioned initial throttle opening degree TΔ0 is determined thereby.

According to the above embodiment, when skid control is performed in which the throttle opening degree TA is adjusted and the slip rate S is feedback-controlled to the optimum range, when a slip condition occurs in which the throttle opening degree needs to be reduced first, first. , the throttle opening is set to a lower throttle opening AO that reduces the engine output in a fully open state at a predetermined ratio, and after the throttle opening is once reduced to this throttle opening TAO, skid control is performed based on the detection of a slip state.

That is, changes in the slip ratio S and the throttle opening degree in the above control are shown in FIG. 6 together with a comparative example based on the conventional example. While the throttle opening TA is opening towards the fully open state in response to the accelerator operation, if the slip rate S increases beyond the set value SL, in the comparative example shown by the chain line, the throttle opening TA changes to the fully open state. After that, the skid control gradually reduces the throttle opening T as the slip rate S is detected, and accordingly the slip rate S gradually decreases from an excessive value to eliminate the slip condition. It takes a long time. On the other hand, in the present invention shown by the solid line, when the slip ratio S exceeds the set value Si, skid control is performed after immediately reducing the throttle opening TA to a predetermined value f*TAo, and the skid control is performed from this predetermined opening TAo. The throttle opening degree TA is gradually reduced based on the detection of the ratio S, and the slip ratio S is also reduced accordingly, so that the slip state can be eliminated in a short time overall.

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

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram to clarify the configuration of the present invention, Fig. 2 is an overall configuration diagram of a specific example, Fig. 3 is a flow chart diagram to explain the operation of the control unit, and Fig. 4 is a throttle opening diagram. Fig. 5 is a characteristic diagram showing the initial throttle opening setting in the engine output characteristics with respect to the engine speed. Fig. 6 is a characteristic diagram showing the initial throttle opening setting with respect to engine speed. FIG. 3 is a characteristic diagram showing a control example together with a comparative example. 1...Car 2,3...
Drive wheel 4.5... Driven wheel 6...
・Engine 7... Slip detection means 8... Skid control means 9... Initial control M setting means 17... Throttle valve 18... Throttle motor 20...Control unit 21-24...
...Speed sensor Figure 1 Figure 2 + g7 Figure 4 Figure 5 7°""LE TA Figure 6 P light

Claims (1)

[Claims] (1) A skid control device for an automobile, comprising a slip detection means for detecting a slip state of a driving wheel, and a skid control means for controlling a driving force according to the slip state,
A skid for an automobile, characterized in that the vehicle comprises an initial control amount setting means for setting a control amount of the skid control means to a control amount that suppresses engine output at a predetermined ratio at an early stage of slip start based on a signal from the slip detection means. Control device.