JPH0459437A - Slip controller for vehicle - Google Patents

Abstract

PURPOSE:To improve the stability of a vehicle by altering a control property forcibly to one attaching importance to the stability in preference to a slip control property manually selected when a travelling condition is detected to reduce the stability of the vehicle. CONSTITUTION:A mode switch 70 sets either a sports mode attaching importance to acceleration property having large desired value SET for an engine and desired value SBT for a brake or a normal mode having both small desired values SET, SBT. A control unit UTR performs slip control according to the set modes and information from respective wheel speed sensors 63-66, a throttle opening sensor 61, vehicle speed sensor 62, accelerator opening sensor 67, motor rotation sensor 68, steering wheel steering angle sensor 69, brake switch 71, etc. When unstable travelling conditions are detected according to the information from a travelling condition detecting sensor group 72, the mode is forcibly changed over to the normal mode having the small desired values SET, SBT.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a vehicular slip/slip control device that prevents the slip value of the driving wheels relative to the road surface from becoming excessive.

(Prior art) Preventing the drive wheels from slipping excessively on the road surface during acceleration, etc. is necessary to effectively obtain the propulsion force of the vehicle and for safety reasons such as preventing the vehicle body from spinning. It is effective on In order to prevent the drive wheels from slipping excessively, it is necessary to reduce the torque applied to the drive wheels, which causes the slip.More specifically, for example, by reducing the torque generated by the engine, All that is required is to apply braking force.

When performing this slip control, depending on how the control characteristics are set, it is possible to perform slip control that emphasizes acceleration performance or to perform slip control that emphasizes vehicle stability, that is, slip convergence of driving force. Tokukai 1986
Publication No. 143171 discloses a device that changes the control characteristics of slip control by correcting the detected drive wheel slip value using a correction coefficient, and this correction coefficient can be changed by turning on a manual switch. , OFF.

(Problems to be Solved by the Invention) As mentioned above, when changing the control characteristics of slip control to a manual type, if slip control is always performed based on the manually selected control characteristics, it will cause a large amount of damage to the drive wheels. Slip may occur, which may cause an unfavorable situation in terms of ensuring the stability of the vehicle.

More specifically, if you are currently manually selecting a control characteristic that emphasizes acceleration and consider turning, the slip value of the drive wheels will become considerably large due to the control characteristic that emphasizes acceleration. This tends to cause undesirable situations in terms of ensuring the stability of the vehicle. Of course,
The driver should be well aware that the manual selection selects control characteristics that emphasize acceleration, but there are cases where ensuring vehicle stability while satisfying acceleration is a particular problem. It would be more preferable if the slip value of the drive wheels could be prevented from becoming too large when the vehicle is in a running state.

The present invention was made in consideration of the above circumstances, and
On the premise that control characteristics emphasizing acceleration can be manually selected, vehicle slippage is designed to prevent situations in which the vehicle becomes significantly unstable as a result of emphasizing acceleration. The purpose is to provide a control device.

(Structure of the Invention) In order to achieve the above object, the present invention has the following structure. That is, a torque adjustment means that adjusts the torque applied to the driving wheels, and one control of a first slip control characteristic that is manually operated and emphasizes acceleration performance and a second slip control characteristic that emphasizes vehicle stability. a control characteristic changing means for selecting a characteristic; a slip control means for controlling the torque adjusting means to converge a large slip of the driving wheels based on the control characteristic selected by the control characteristic changing means; a running state detection means for detecting a running state where the stability of the vehicle is reduced; and when the running state detection means detects a running state where the stability of the vehicle is reduced, the slip control is performed. The control characteristic changing means sets the control characteristic used by the means to the aforementioned second control characteristic in preference to the control characteristic selected by the control characteristic changing means.

When returning to the first control characteristic manually selected from the second control characteristic emphasizing stability by the control characteristic changing means, the driving condition detecting means detects a driving condition that deteriorates the stability of the vehicle. It is preferable to add a condition such that the operation is performed not only when it is confirmed that the vehicle is not running, but also when the steering angle is small, that is, when the steering wheel is traveling almost straight.

(Operations and Effects of the Invention) As described above, according to the present invention, slip control can be performed with characteristics that suit the driver's preference by selecting control characteristics manually in principle. When the stability of the vehicle deteriorates, control characteristics that prioritize stability are forcibly changed over manual selection. It is possible to prevent a decrease in vehicle stability.

In addition, by limiting the return from the control characteristic that emphasizes stability to the manually selected control characteristic that emphasizes acceleration to when the steering wheel angle is small and the steering wheel is traveling almost straight, the control characteristic can be restored. This is preferable in terms of preventing a situation in which the stability of the vehicle is temporarily lowered due to this, and also in terms of making it easier for the driver to respond when the control characteristics are restored.

(Example) Examples of the present invention will be described below based on the accompanying drawings. In the embodiment, slip control is performed by reducing engine generated torque by reducing the throttle valve opening of the engine and by applying brake force to the driving wheels.

In FIG. 1, automobile A has left and right front wheels IFL and 1.
F R is the driven wheel, and left and right rear wheels IRL and IRR
is considered to be the driving wheel. That is, the torque generated by the engine 2 mounted on the front of the vehicle is transmitted to the left rear wheel IRL via the left drive wheel 6L after passing through the automobile transmission 3, propeller shaft 4, and differential gear 5. , is transmitted to the right rear wheel IRR via the right drive wheel 6R.

Transmission Related The automatic transmission 3 includes a torque converter 11 and a multi-speed gear mechanism 12. As is known, the speed change gear mechanism 12 is hydraulically operated, and in this embodiment has four forward speeds and one reverse speed. That is, the speed is changed by changing the combination of energization and demagnetization of the plurality of solenoids 13a incorporated in the hydraulic circuit. Further, the torque converter 11 is engaged and disengaged by operating the hydraulically operated lock-up clutch IIA and switching between energizing and demagnetizing a solenoid 13b incorporated in the hydraulic circuit.

The solenoids 13a and 13b are controlled by an automatic transmission control unit UAT. As is known, this control unit-UAT stores in advance a shift characteristic and a lock-up characteristic, and performs shift control and lock-up control based on this characteristic. For this control, the control units tJ, AT receive human power from a throttle opening signal (accelerator opening signal) and a vehicle speed signal (rotational speed signal of the propeller shaft 4 in the embodiment) from the sensors 61 and 62.

Each wheel IFR-IRR related to brake fluid pressure adjustment includes brakes 21FR to 21R.
R is provided. Each of these brakes 2IFR~21R
R caliper (wheel cylinder) 22FR~22RR
Brake fluid pressure is supplied to the brake cylinders through pipes 23FR to 23RR.

The configuration for supplying brake fluid pressure to each brake 21FR121RR is as follows. First, the depression force of the brake pedal 25 is applied to a hydraulic booster 26.
The power is boosted by the power and transmitted to the tandem mask cylinder. The first discharge port 2 from this mass cylinder 27
A brake pipe 23FL for the left front wheel is connected to 7a, and a brake pipe 23FR for the right front wheel is connected to the second discharge port 27b of the master cylinder 27.

The booster 26 is supplied with hydraulic pressure from a pump 29 via a pipe 28, and excess hydraulic pressure is returned to the reservoir tank 31 via a return tube 30. A branch pipe 28a branched from the pipe 28 is connected to a confluence section a, which will be described later, and an electromagnetic on-off valve 32 is connected to this branch pipe 28a.

In addition, the boosting hydraulic pressure generated by the booster 26 is applied to the piping 3
3 to the confluence part a, and an electromagnetic on-off valve 34 is also connected to this pipe 33. In the upper two pipes 33, in parallel with the on-off valve 34, there is a one-way valve 35 that allows only flow toward the confluence part a.
is provided.

-Brake pipe 2 for left and right rear wheels for confluence part a in F
3RR223RL is connected. This pipe 23RR
An electromagnetic on-off valve 36A or 37A is connected to 123RL, and the electromagnetic on-off valve 36 is connected to the relief passage 38L or 38R connected downstream of the valve 36A or 37A.
B or 37B is connected.

Answers 32.34.36A, 37A, 36B, 3 mentioned above.
7B is controlled by a control unit UTR for slip control. That is, when slip control is not performed, the valve 32 is closed, the valve 34 is opened, one of the valves 36B, 37B is closed, and the valves 36A, 37A are opened, as shown in the figure. As a result, when the brake pedal 25 is depressed, brake fluid pressure is supplied to the front wheel brake 21FR121F I- via the mask cylinder 27. Also,
Rear wheel brake 2] Boosting hydraulic pressure corresponding to the depression force of the brake pedal 25 from the hydraulic booster 26 is supplied to the RR 121RL as brake hydraulic pressure via the pipe 33.

As will be described later, when the slip value of the rear wheels IRR1IRL serving as the driving wheels relative to the road surface becomes large and slip control is performed, the valve 34 is closed and the valve 32 is opened. And the days of valves 36A, 36f3 (37A, 37B)
Through tee control, the brush fluid pressure is maintained, raised, and lowered. More specifically, assuming that valve 32 is open, answers 36A, 36B, 37A, 37B
Brake fluid pressure is maintained when valve 36 is closed.
Pressure increases when valve A (37A) is open and valve 36B (37B) is closed, and pressure decreases when valve 36A (37A) is closed and valve 36B (37B) is open. Then, the one-way hydraulic pressure that passes through the branch pipe 28a is transferred to the one-way valve 3.
50 action, it is prevented from acting as a reaction force against the brake pedal 25.

When the brake pedal 25 is depressed while performing such slip control, brake fluid pressure from the booster 26 corresponding to the depression is supplied to the rear wheel brake 21RR121RL via the one-way valve 35. Ru.

The control unit tJTR for controlling traction control related to adjustment of engine generated torque applies brakes to the driving wheels IFL, IRR in order to reduce the torque applied to the driving wheels IFL, 2RR, and also adjusts the torque generated by the engine. It also reduces the For this reason, a main throttle valve 42 and a sub-throttle valve 42A are arranged in series with each other in the intake passage 41 of the engine. The main throttle valve 42 is interlocked with the accelerator 43 via a linkage mechanism 112 such as a wire, and as shown in FIG. determined. The sub-throttle valve 42A is driven by the motor 106 for slip control, and when slip control is not performed, the sub-throttle valve 42a is at the 100% opening position, and the opening of the intake passage 41 is at the main throttle position. It depends on the opening degree of the valve 42. Also, during slip control, the opening degree of the sub-throttle valve 43A is made smaller than the opening degree of the main throttle valve 42,
The opening degree of the intake passage 41 depends on the opening degree of the sub-throttle valve 42A.

(The following is a blank space) Overview of slip control The control unit tJTR for slip control performs brake control 5 and engine control by controlling the motor 106 during slip control. This control unit UTR includes sensors 63 to 66 that detect the speed of each wheel.
In addition to input signals from the sensor 61, the throttle opening signal from the sensor 62, the vehicle speed signal from the sensor 62, the accelerator opening signal from the sensor 67, and the motor 106 from the sensor 68.
The opening signal from the sensor 69, the steering angle signal from the sensor 69, the mode signal from the manually operated switch 70, the brake signal from the brake switch 71 that is turned on when the brake pedal 25 is depressed, Signals from a sensor group 72 that detects the running state are manually input. The sensor group 72 for detecting the driving state is provided to determine whether or not to forcibly switch the control characteristic for slip control to one that emphasizes stability. The blinker that indicates that the
For example, by using radar, etc.), it is possible to detect whether the vehicle is traveling on a winding road (for example, by determining from the state of steering wheel operation and changes in vehicle speed within a predetermined period of time).

FIG. 3 shows the contents of slip control, focusing on engine control and brake control. In this Figure 3, the target value for the engine (target slip of the drive wheels (m))
is indicated by SET, and the target value for the brake is indicated by SBT (SBT>5ET).

Now, until time t4, there is no large snop of the driving wheels, so the actual throttle opening, that is, the opening of the intake passage 41, is based on the opening of the main throttle valve 42 corresponding to the accelerator opening. becomes. That is, the basic throttle opening TH-B is obtained in light of the basic throttle characteristics shown in FIG. 2 (the opening of the auxiliary throttle valve 42A is assumed to be 100% or the same as the opening of the main throttle valve 42).

At time t, a large slip occurs when the slip value of the driving wheels reaches the engine target (M S E T. In the embodiment, slip control is performed when the slip value of the driving wheels exceeds SET. and start the
At this time point t3, the opening degree of the sub-throttle opening degree 42A is reduced all at once to the lower limit control value SM (feedforward control). Then, once SM is set, the opening degree of the sub-throttle valve 42A is feedback-controlled so that the slip value of the driving wheels becomes the engine target value SET. At this time, the target throttle opening is TH-M (motor 106
opening degree; operation amount) (TH-M≦TH-B).

At time t2, the slip value of the driving wheels is equal to the brake target value S.
This is when the pressure exceeds ET, and at this time, brake fluid pressure is supplied to the brakes 21RR121RL of the driving wheels (slip control is started by both engine control and brake control).

Of course, the brake fluid pressure is feedback-controlled so that the slip value of the driving wheels becomes the brake target value SET.

At time t3, the slip value of the driving wheels has become less than the brake river mouth target value SBT, and as a result, the brake fluid pressure is gradually lowered and eventually reaches zero. However, slip control by the engine is still continued.

In the embodiment, the condition for ending the slip control is when the accelerator is fully opened.

Details of Slip Control Next, details of the slip control by the control unit UTR will be explained with reference to a flowchart. In addition,
P or R used in the following description indicates a step.

■Figure 4 (main) First, at Pl in Figure 4, signals from each sensor or switch are read.

Next, in P3, the rotational speed VJ of the driven wheel is subtracted from the rotational speed VK of the driving wheel (thereby, the actual slip value S of the driving wheel is calculated).

In calculating the slip value S, for example, for an engine, the average value of the rotational speeds of the left and right driven wheels is used as VJ, and the larger one of the rotational speeds of the left and right driven wheels is selected as VK. Also, for brakes, V
J is the same as that for the engine, and the individual rotational speeds of the left and right drive wheels are selected as VK (in the case where the braking force to the left and right drive wheels is controlled independently).

At P4, it is determined whether the accelerator is currently fully open. When the determination in P4 is No, it is determined in P5 whether the slip flag is 1 or not. This slip flag means that slip control is in progress when it is I. If this P5 is No for each ell, the snop value S of the driving wheel is set to the engine river target value SET in P6.
It is determined whether or not the value is greater than or equal to the value. This P6 judgment is YES
In the case of S, the slip flag is set to 1 at Pl, and the lower limit control value SM is set as described later, and then the process moves to P8. Further, if the determination in P5 is YES, the process proceeds to P8 without passing through P6 and P1.

At P8, brake control, which will be described later, is performed.

The content of this brake control is the determination and realization of the brake target value SBT.

After P8, in P9, the engine target value SET is determined as described later, and the opening degree of the sub-throttle valve 42A required to realize this SET (motor 1
06) TH-M is determined as described below.

Note that the realization of this SET, that is, the output of TH-M, is performed by interrupt processing for throttle control, which will be described later.

If YES in P4, is it a slip system? Since it is time to end wholesale, the slip flag is 0 in PIO.
will be reset to

■Figure 5 (P8 in Figure 4) In Figure 5, which shows the contents of brake control, first, in P21, the target value SBT for the brake is determined as described later, and then in P22, the slip of the drive wheel is determined. value S
It is determined whether or not is greater than or equal to SBT. If the determination in P22 is YES, the target value SET is set in P23.
The brake force Pn (the amount of operation of the valves 36A, 36B or 37A, 37B=duty ratio) required to achieve this is determined. After this, the brekika P determined in P24
A signal corresponding to n is output to the valve. When the determination in P22 is NO, the brake fluid pressure is gradually lowered in P25 (it may be zero).

■ Fig. 6 Fig. 6 is performed by interrupting the flowchart of Fig. 4 at predetermined time intervals, and the sub-throttle valve 42A
This controls the driving of the First, in P31,
Whether the slip flag has changed from O to 1,
That is, it is determined whether or not it is time t1 in FIG. 3, and if YES in P31, the final target throttle opening Tn (motor opening) is determined in P32 as described below. It is set as the lower limit control value SM.

When the determination in P31 is No, it is determined in I) 33 whether the slip flag is 1 or not. This P3
If the determination in step 3 is YES, the final target throttle opening Tn is set at P34 as the throttle opening T)l-M determined at P9 in FIG.

If the determination in P33 is NO, this means that slip control is not performed. At this time, in P35, Tn is set to 1.
Set it to 00.

After P34 or P35 (P32), the motor 106 is driven in P36 so that the opening degree of the auxiliary throttle valve 42A becomes the final target throttle opening degree Tn.

Next, an example of determining the engine target value SET, brake target value SET, and lower limit control value SM (see time t1 in FIG. 1) when performing the slip control described above will be explained.

First, FIG. 7 shows a block diagram of a circuit that determines SET and SET, and the determining parameters include vehicle speed, accelerator opening, steering wheel angle, and the four main operations of mode switch Sochi 70. and the maximum coefficient of friction of the road surface LL+t+
This is ax. In FIG. 7G, the basic value 5TAO of SET and the basic value 5BTO of SBT. The maximum friction coefficient is stored in the map 81 as a parameter (STBO>5TAO). And this basic value is 5TB
Add a correction gain coefficient KD of 1 hexagram to O and 5TAO, respectively.
By combining, SET and 5BT7j≦ are obtained.

The above correction gain coefficient DK is equal to each gain coefficient VG and ACP.
It is obtained by multiplying G, 5TRG and MODEG and adding G. The gain coefficient VG uses vehicle speed as a parameter and is stored as a map 82. The gain coefficient ACPG4 uses the accelerator opening degree as a parameter, and is stored as Ma.Tsub.83. The gain coefficient 5TRG uses the steering wheel angle as a parameter and is stored as a map 84. Gain coefficient MO
DEC is manually selected by the driver and is stored as table 85. In this table 85, a sports mode (MODEC=1.
2) and normal mode (MODEG) that emphasizes stability.
= 1.0) is set. That is, in the sports mode where emphasis is placed on acceleration, the target straight SET and SBT for the engine and brake are each increased by 20% in this embodiment, compared to the normal mode where stability is placed emphasis.

As shown in FIG. 8, the lower limit control value SM is recorded as a map 91 using the vehicle speed and the maximum coefficient of friction of the road surface as parameters. In addition, in FIG. 8, μmax =
1 indicates the smallest coefficient of friction, and μmax=5 indicates the largest coefficient of friction (the same applies to map 81 in FIG. 7).

Note that the maximum friction coefficient of the road surface may be manually set by the driver, but may also be estimated as follows, for example. That is, the maximum friction coefficient is estimated according to the magnitude of the acceleration obtained by subtracting the rotational speed of the driven wheel after a predetermined time has elapsed from t from the rotational speed of the driven wheel at t2:07 in FIG. You can also do this. Alternatively, the maximum friction coefficient may be estimated based on the maximum acceleration of the rotational speed change (acceleration) monitored over the entire period during the previous slip control.

Ignition timing control A control unit UIG is provided to control the ignition timing of the engine. This UIG basically consists of sensor 6
The ignition timing is determined based on the throttle opening signal from sensor 72 and the engine speed signal from sensor 72. Then, by outputting the determined ignition timing to the igniter 51, the primary current of the ignition coil 52 is cut off at the timing of this ignition timing. A high-voltage secondary current generated by this interruption of the secondary current is supplied to the spark plug 54 via the destroyer 53. Note that ignition timing control is not related to slip control in this embodiment, so further explanation will be omitted.

Control for slip control, change in gender (Figure 9) Now, next.
A description will be given of changes in control characteristics for slip control. First, the control characteristics are basically determined by switching the manually operated switch 70 to select between a sports mode where slip control target values SET and SBT are large and which emphasizes acceleration, or a normal mode where the target values SET and SBT are small. It is selected from two types. And in the state of manual selection of sports mode,
When the vehicle's stability deteriorates, the mode is forcibly changed to normal mode.

In addition, the condition for returning to the manually selected sport mode from the state where the mode has been forcibly changed to normal mode is that a predetermined period of time has elapsed since the driving condition that degraded the vehicle stability was canceled. This is the case when both conditions are satisfied: the steering wheel angle is small, and the steering angle is small.

On the premise of the above, switching of control characteristics will be explained with reference to the flowchart shown in FIG.

First, in P41, by checking the operating state of the switch 70, it is determined whether the normal mode is selected. If the result of P41 is YES, P4
In step 2, the control characteristics for slip control are set to normal mode.

When the determination at P41 is No, that is, when the sports mode is currently selected, it is determined through determinations from P43 to P45 whether the driving state is such that the driving state is forcibly changed to normal moto. More specifically, when driving on a winding road, when the distance between vehicles is small, or when the turn signal is activated, after resetting the timer in P46, Pd2
In this case, the control characteristics for slip control are forcibly set to normal mode.

When all of the determinations from P43 to P45 are No, P
After the timer is counted up in step 48, it is determined in step P49 whether or not the control characteristic for slip control that is currently actually set (used) is the normal mode. If the determination in P49 is No, the control characteristic that is currently actually set is the sports mode, so in this case, the sports mode is directly set in P54.

When the determination in P49 is YES, it means that the control characteristic currently being actually used is the normal mode, even though the manual selection is for the sports mode. At this time, on the condition that the steering wheel angle is less than 30 degrees at P2O and the timer value is confirmed to be greater than the predetermined value at P51, P53
Switch to sports mode. Also, P2O
, P51 is NO, it means that the conditions for switching to sports mode are not met, and P52
remains in normal mode.

Other Embodiments (FIGS. 1O and 11) FIGS. 10 and 11 show other embodiments of the present invention.

In this embodiment, the main throttle valve 42 is controlled by, for example, a 4F motor, so that the accelerator opening (in contrast, the opening of the main throttle valve 42 can be changed). More specifically, in order to change the running feeling of the vehicle, in the embodiment, the throttle characteristics as shown in FIG. 2 are set as the normal mode, and the throttle characteristics as shown in FIG. 11 are set as the power mode. This switching of both throttle characteristics is performed by a manual selection/sochi (not shown) that is manually operated by the driver.These two throttle/sotor characteristics are changed if the accelerator opening is the same (provided that the accelerator opening is 0%). and 100
%), the opening degree of the main slot/sottle valve 42 is set to be larger than that in the power mode or the normal mode.

When the above-mentioned NOW mode is selected as the control characteristic for slip control, the slot/sottle characteristic is set as the manual selection.

On the other hand, when normal mode is manually selected as the control characteristic for slip control, even if power mode is manually selected as the throttle characteristic, when slip control is performed, the throttle characteristic is Forced to normal mode. and,
The conditions for returning to the power mode from a state in which the throttle characteristic is forcibly set to the normal mode are the same as the conditions for returning the control characteristic for slip control from the normal mode to the spora mode.

The above-mentioned throttle characteristic switching will be explained with reference to the flowchart shown in FIG. 10.

First, in P61, it is determined whether the switch 70 for selecting the control characteristic for slip control is in the sports mode selection state. If the determination in P61 is YES, the throttle characteristics (
(Driving feel mode) is set as manually selected.

When the determination in P61 is No, it is determined in P65 whether or not slip subwriting is currently in progress. When the determination in P65 is YES, the timer is reset in P66, and then the throttle characteristic is forcibly set to normal mode in P67.

When the determination in P65 is No, the timer is counted up in P68, and then in P2O it is determined whether or not the throttle characteristic selection switch is in the power mode selection state. When this P2O determination is No, P
At 74, the throttle characteristics are set to normal mode.

If the P2O determination is YES, the throttle characteristics change to power mode at P73, provided that the steering wheel angle is less than 30° at P2O and the timer value is greater than a predetermined value at P2O. is set to When the determination in either P2O or P71 is No, the throttle characteristic is set to normal mode in P72.

Although the embodiments have been described above, the present invention is not limited thereto, and includes, for example, the following cases.

(2) Although the slip value of the driving wheel is shown as the deviation of the rotational speed between the driving wheel and the driven wheel, it can also be shown as the ratio thereof.

(2) Slip control may be performed using any appropriate method such as engine control only or brake control only.

■As a method to change the control characteristics for slip control,
By correcting the detected drive wheel slip value (correct so that the detected value in normal mode is larger than the detected value in sports mode), or by correcting the control gain (responsiveness in normal mode) An appropriate method may be adopted, such as making the response faster than in sports mode).

■The determination of P61 in Fig. 10 is not based on the operating state of the switch 70, but on P42) P47, P52 to P52 in Fig. 9.
It may be determined whether the control characteristic set in 54 is a sports mode or not.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing an example of basic throttle characteristics that correspond to the main throttle valve and the accelerator opening. FIG. 3 is a time chart showing an outline of slip control. 4 to 6 and 9 are flowcharts showing control examples of the present invention. FIG. 7 is a circuit diagram for determining respective slip target values for the engine and the brake. FIG. 8 is a diagram showing a map for determining the lower limit control value in slip control. FIG. 10 is a flowchart showing another embodiment of the present invention. FIG. 11 is a diagram showing another example of basic throttle characteristics that correspond to the main throttle valve and the accelerator opening. IFRlIFL: Driven wheel. IRRlI RL: Drive wheel 21FR121FL Nibrake 21RR121RL Nibrake 2: Engine 32: Solenoid on-off valve (for slip control) 36A, 36B
: Solenoid on-off valve (for brake force adjustment) 37A, 37B: Solenoid on-off valve (for brake force adjustment) 42: Main throttle valve 42A: Sub-throttle valve (for slip control) 63-66
: Sensor (wheel speed) 69: Sensor (steering wheel angle) 70: Switch (control characteristic selection) 72 sensor group (driving condition) 106: Motor (for driving sub-throttle valve) UTR: Control unit (for slip control) 2nd Figure (TH-B) Action 2) Opening force 1 Figure 4 Figure 5 Figure

Claims (2)

[Claims] (1) A torque adjustment means for adjusting the torque applied to the driving wheels; and one of a first slip control characteristic that is manually operated and emphasizes acceleration performance and a second slip control characteristic that emphasizes vehicle stability. a control characteristic selection means for selecting a control characteristic; and a slip control means for controlling the torque adjustment means to converge a large slip of the driving wheels based on the control characteristic selected by the control characteristic selection means. , a running state detection means for detecting a running state where the stability of the vehicle is reduced; and when the running state detection means detects a running state where the stability of the vehicle is reduced, the slippage is detected. A slip control for a vehicle, comprising: control characteristic changing means for setting the second control characteristic in preference to the control characteristic selected by the control characteristic selection means as the control characteristic used by the control means; Device. (2) In claim 1, the return condition for returning to the first control characteristic from the state in which the second control characteristic is preferentially selected by the control characteristic changing means is the driving condition detecting means. This is set when no driving condition that would reduce the stability of the vehicle has been detected and when the steering wheel angle is below a predetermined value.