JPH04292252A - Traction control unit for vehicle - Google Patents

Abstract

PURPOSE:To drive a vehicle with various patterns in conformity with a driver's request by making slip control temporarily suspendible temporarily as occasion calls during this slip control. CONSTITUTION:This control unit is provided with a cancel switch 79 for a suspension mode with which control is temporarily suspended during execution of slip control, in addition to an ordinary traction switch 78 for selecting a control mode executing the slip control and a prohibitive mode unexecuting this slip control, and thereby a mode of a control means 70 is determined by a mode decision means 80 according to each making state of both these switches 78, 79.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction control device for a vehicle.

0002

[Prior Art] A traction control device for a vehicle detects the amount of slip of the drive wheels in order to prevent the drive wheels from slipping due to excessive drive torque and reducing acceleration performance when the vehicle accelerates. It is generally known as a device that controls the engine output and the application of braking force to the wheels (reducing the engine output or increasing the braking force) so that the slip amount of the drive wheels reaches a target value.

[0003] In such a traction control device, a means for detecting the operation of the handbrake of the vehicle is provided, and when the handbrake is operated, slip control (
There is a proposal to prevent the deterioration of acceleration and the occurrence of engine stalling by prohibiting traction control (see Japanese Patent Laid-Open No. 62-289460).

0004

[Problems to be Solved by the Invention] Generally speaking, in a traction control device, if a slip occurs in the drive wheels, the driving force will not increase even if the accelerator is depressed. It is not possible to intentionally cause the rear wheels to slip by depressing the accelerator while turning a corner, resulting in an oversteer-like turn. Additionally, when only one wheel is resting on a road surface with a low coefficient of friction, such as a snowy road, slip control is performed based on the slip of this one wheel, and even if the driver depresses the accelerator, the acceleration will be reduced against the driver's will. You end up in a situation where you can't get it. In such a situation, performing slip control becomes disadvantageous in terms of acceleration, which is contrary to the original purpose.In particular, since the driver cannot operate the vehicle according to his/her will, it becomes It also delays the ability to escape from a one-wheel slip situation.

On the other hand, a vehicle equipped with a traction control device is usually provided with a traction switch for selecting in advance whether or not to perform slip control. However, even if the traction switch is turned off while the slip control is being performed, the slip control is not immediately stopped. However, if the slip control is suddenly stopped, the driving force will suddenly increase and the running of the vehicle may become unstable.

In other words, an object of the present invention is that even when slip control is being performed, it is possible to immediately and temporarily stop this slip control as needed, so that the vehicle can run in accordance with the driver's request. The purpose is to do so.

[0007]

[Means for Solving the Problems] In order to solve these problems, the present invention provides a switch, in addition to a normal traction switch, that can immediately and temporarily stop this slip control as necessary. It is.

Specifically, the specific means for this purpose is a control means for controlling the drive of the drive wheels so that when the slip amount of the drive wheels with respect to the road surface exceeds a predetermined threshold value, this slip amount becomes a target value. A traction control device for a vehicle, comprising: a control mode switch for selecting a control mode for causing the control means to execute control when the slip amount of the drive wheels exceeds the threshold; a prohibition mode switch for selecting a prohibition mode that prevents the control means from executing the control even if the amount of slip exceeds the threshold; The apparatus is characterized by comprising: a stop mode switch for selecting a stop mode for temporarily stopping; and a mode determining means for determining the mode of the control means based on turning on each of the mode switches. (Hereinafter, this will be referred to as the first means).

In this case, the steering angle detecting means and the accelerator depression amount detecting means are provided, and when the control mode switch is turned on and the cancel mode switch is turned on, the steering angle is equal to or larger than a predetermined value, and When the amount of accelerator depression is equal to or greater than a predetermined value, setting the mode of the control means to the stop mode is an effective means for performing the above-mentioned accelerator turn (hereinafter, this will be referred to as the second means).

[0010]Furthermore, when the abort mode switch is turned on from a state in which the control mode switch is turned on, and a set time has elapsed since the abort mode switch was turned on, the mode of the control means is set to the control mode. This is an effective means for preventing unnecessary continuation of the state in which the slip control has been stopped (hereinafter, this will be referred to as the third means).

Furthermore, a steering angle detecting means is provided, so that when a control mode switch is turned on and a stop mode switch is turned on, a first set time has elapsed since the turn on of the stop mode switch, and the steering angle is turned on. When the state in which the steering angle detected by the angle detection means is substantially zero continues for the second set time, changing the mode of the control means to the control mode means that it is truly unnecessary to stop the slip control. This is an effective means for restarting slip control at this point (hereinafter, this will be referred to as the fourth means).

0012

[Operation] In the first means, even when slip control is performed by turning on the control mode switch,
By turning on the abort mode switch, the mode can be switched from the control mode to the abort mode, and the slip control can be immediately aborted, making it possible to perform an accelerator turn. In addition, even in a one-wheel slip state, the above-mentioned slip control is canceled and the driver operates the vehicle according to his/her own will.
It will be possible to gain acceleration or escape from a one-wheel slip situation. The suspension of the slip control is temporary, and the slip control can be restarted later.

[0013] In the second means, when the abort mode switch is turned on and the steering angle is at least a predetermined value and the accelerator depression amount is at least a predetermined value, the driver has truly aborted the slip control. This can be seen as when the intention is to perform an accelerator turn. At this time, the mode of the control means is switched from the control mode to the stop mode, and since the slip control will not be canceled if the stop mode switch is simply turned on, the running state of the vehicle is changed by turning on the stop mode switch. It is possible to stop slip control when necessary and perform accelerator turns smoothly while preventing sudden instability. Furthermore, even if the cancel mode switch is turned on by mistake, the slip control will not be canceled, and the running state of the vehicle will not become temporarily unstable due to careless cancellation of the slip control.

[0014] In the third means, the mode of the control means becomes the control mode after the set time has elapsed since the abort mode switch is turned on, so that the abort mode is selected without the need to turn the control mode switch on again. Alternatively, a state in which slip control is canceled is not continued unnecessarily. Therefore, even if you forget to turn on the control mode switch, slip control will be performed even if the accelerator pedal depression amount exceeds a predetermined value and the steering angle exceeds a predetermined value, for example when cutting a curve at a road intersection. It turns out.

[0015] In the fourth means, the control mode is not entered if the state in which the steering angle is substantially zero does not continue for the second set time even after the first set time has elapsed since the stop mode switch is turned on. Therefore, when the driver attempts to perform an accelerator turn, it is possible to prevent the slip control from being resumed and such driving to be impossible, that is, to prevent the vehicle from being in a driving state contrary to the driver's intention. and,
When the first set time has elapsed and the second set time has elapsed, it can be assumed that the driver no longer intends to perform an accelerator turn, and at this time, the abort mode is selected. Since the control mode is entered as if the necessity is no longer present, it is possible to avoid the problem of deterioration of the running performance of the vehicle due to unnecessary suspension of slip control.

[0016]

Therefore, according to the first means, a stop mode switch is provided in addition to the control mode switch and the prohibition mode switch, so that slip control can be temporarily stopped when necessary. In addition to driving in a slip control state, the vehicle can be driven in various patterns according to the driver's requests, such as accelerator turn driving, acceleration driving or escape driving based on the driver's intention when one wheel is slipping. You will be able to do this.

According to the second means, the steering angle detection means and the accelerator depression amount detection means are provided, and when the abort mode switch is turned on, the steering angle is equal to or greater than a predetermined value and the accelerator depression amount is a predetermined value. Since the mode determining means is configured to switch the mode of the control means from the control mode to the abort mode when the value is greater than or equal to the value, the driving condition of the vehicle can be prevented from suddenly becoming unstable when the abort mode switch is turned on. However, the slip control can be canceled when necessary to smoothly perform an accelerator turn.

According to the third means, since the mode determining means is configured so that the mode of the control means becomes the control mode after the set time has elapsed from the turning on of the abort mode switch, it is possible to avoid turning on the control mode switch by forgetting to turn on the control mode switch. However, the slip control can be automatically restarted, and the running stability or acceleration of the vehicle can be ensured in subsequent driving.

According to the fourth means, the mode of the control means is changed when the first set time has elapsed since the stop mode switch was turned on and the state in which the steering angle is substantially zero continues for the second set time. Since the mode determining means is configured so that the driver switches from the abort mode to the control mode, the mode is changed from the abort mode to the control mode when it can be assumed that the driver truly has no intention of aborting the slip control (performing an accelerator turn). be able to return it.

[0020]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

FIG. 1 shows the overall configuration of a traction control device for a vehicle, and this vehicle has left and right front wheels 2FL,
2FR is used as a driven wheel, and left and right rear wheels 2RL and 2RR are used as driving wheels, and there is a TRC control means 70 for controlling the drive of the driving wheels 2RL and 2RR to control traction and for performing slip control. T for selecting control mode and prohibition mode in which slip control is not executed
It includes an RC switch 78, a cancel switch 79 for selecting a stop mode in which slip control is temporarily stopped during execution of slip control, and mode determining means 80. The TRC control means 70 of this example performs brake control, engine control, and lock-up control via the AT controller 60 for speed change control during slip control (traction control).

First, the above vehicle has an engine 1 at the front of the vehicle body.
is installed, and the torque generated by the engine 1 passes through the automatic transmission 3, propeller shaft 4, and differential gear 5, and then is transmitted to the left rear wheel 2RL via the left drive shaft 6L, and then to the left rear wheel 2RL via the right drive shaft 6R. The power is transmitted to the right rear wheel 2RR.

The automatic transmission 3 includes a torque converter 1
1 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 change is performed by changing the combination of excitation and demagnetization of the plurality of solenoids 13a incorporated in the hydraulic circuit. Further, the torque converter 11 has a hydraulically operated lock-up clutch 11a, and is engaged and disengaged by switching between excitation and demagnetization of a solenoid 13b incorporated in the hydraulic circuit.

The solenoids 13a and 13b are controlled by an AT controller 60 for controlling the speed change of the automatic transmission 3. The AT controller 60 stores shift characteristics and lockup characteristics in advance, and performs shift control and lockup control based on these. Therefore, the AT controller 60 receives throttle opening signals from a main throttle opening sensor 61 that detects the opening of the main throttle valve 43 and a subthrottle opening sensor 62 that detects the opening of the subthrottle valve 45. , a vehicle speed signal (in the embodiment, the rotational speed signal of the propeller shaft 4) from a vehicle speed sensor 63 that detects the vehicle speed.

- Braking force adjustment mechanism - each wheel 2FL, 2FR
, 2RL, and 2RR are provided with brakes 21FL to 21RR for the brake control described above. Caliper (wheel cylinder) of each brake 21FL to 21RR
22FL to 22RR have piping 23FL to 23, respectively.
Brake fluid pressure is supplied via RR. The configuration for supplying this brake fluid pressure is as follows.

First, the force applied to the brake pedal 25 is boosted by a hydraulic pressure booster 26 and transmitted to a tandem-type master cylinder 27 . A brake pipe 23FL for the left front wheel is connected to the first discharge port 27a of the master cylinder 27, 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 pipe 30. A branch pipe 28a branched from the piping 28 is connected to a confluence section a, which will be described later, and an electromagnetic on-off valve 32 is interposed in this branch pipe 28a. Further, the boosting hydraulic pressure generated by the booster 26 is supplied to the confluence section a through a pipe 33, and this pipe 33 is also provided with an electromagnetic on-off valve 34. It is set up. And the above piping 3
3 is provided with a one-way valve 35 in parallel with the on-off valve 34 that allows flow only toward the confluence section a.

Brake pipes 23RL and 23RR for the left and right rear wheels are connected to the merging portion a. This piping 2
3RL and 23RR are equipped with an electromagnetic on-off valve 36A or 3
7A is interposed, and the on-off valves 36A, 37A
An electromagnetic on-off valve 36B or 37B is connected to the relief passage 38L or 38R connected downstream.

[0029] Each of the on-off valves 32, 34, 36A, 37A
, 36B, and 37B are controlled by a TRC control means 70 for slip control. That is, when slip control (brake control) is not performed, the on-off valve 32 is closed, the on-off valve 34 is opened, and the on-off valves 36B,
37B is closed, and on-off valves 36A and 37A are opened. Thereby, when the brake pedal 25 is depressed, brake fluid pressure is supplied to the front wheel brakes 21FL and 21FR via the master cylinder 27. Further, boosting hydraulic pressure corresponding to the depression force of the brake pedal 25 from the hydraulic booster 26 is supplied to the rear wheel brakes 21RL and 21RR as brake hydraulic pressure via a pipe 33. .

Further, as will be described later, when the slip value of the rear wheels 2RL and 2RR as driving wheels with respect to the road surface becomes large and slip control is performed, the on-off valve 34 is closed and the on-off valve 32 is opened. And the on-off valve 36A, 3
6B (37A, 37B) maintains, increases, and decreases the brake fluid pressure. More specifically, assuming that the on-off valve 32 is open, the brake fluid pressure is maintained when the on-off valves 36A, 36B, 37A, and 37B are closed, and the on-off valve 36A (37A
) opens and when the on-off valve 36B (37B) is closed, the pressure increases, the on-off valve 36A (37A) closes, and the on-off valve 3
When 6B (37B) is open, the pressure decreases. The brake fluid pressure that has passed through the branch pipe 28a is prevented from acting as a reaction force against the brake pedal 25 due to the action of the one-way valve 35.

When the brake pedal 25 is depressed during such slip control, the brake fluid pressure from the booster 26 corresponding to the depression is applied to the one-way valve 35.
It is supplied to rear wheel brakes 21RL and 21RR via.

- Driving force adjustment mechanism - The TRC control means 70 performs brake control on the driving wheels 2RL and 2RR in order to reduce the driving torque of the driving wheels 2RL and 2RR, and also controls the driving wheels 2RL and 2RR.
The driving force transmitted to the engine 1, that is, the torque generated by the engine 1 is also reduced. Therefore, the intake passage 41 of the engine 1
The above-mentioned main throttle valve 43 connected to the accelerator pedal 42 and the above-mentioned sub-throttle valve 45 connected to the throttle opening adjustment actuator 44 are arranged, and the sub-throttle valve 45 is controlled by the above-mentioned TRC control means. 7
0, it is controlled via the actuator 44.

-TRC control means 70- The TRC control means 70 includes a throttle opening sensor 61,
In addition to inputting signals from 62 and vehicle speed sensor 63,
Wheel speed sensor 6 that detects the speed of each wheel 2FL to 2RR
A wheel speed signal from 6FL to 66RR, a depression amount signal from an accelerator depression amount sensor 67 that detects the amount of accelerator depression, a steering angle signal from a steering angle sensor 69 that detects a steering wheel angle, and a manually operated switch. A mode signal from 71 is input.

The TRC control means 70 also includes an input interface that receives signals from each of the sensors, a microcomputer consisting of a CPU, ROM, and RAM, an output interface, and valves 32, 36A, 3.
7A, 36B, 37B and a drive circuit for driving the actuator 44, the ROM is provided with control programs and various maps necessary for slip control, and the RAM is provided with various types of information necessary to execute the control. Memory is provided.

<Specific configuration of TRC control means 70> TR
As shown in FIG. 2, the C control means 70 includes a slip detection means 72, a target value (threshold value) setting means 73, a road surface friction coefficient calculation means 74, a slip determination means 75, and a control amount calculation means 76.

(Regarding the slip detection means 72) The amount of slip of the drive wheels is determined by wheel speed sensors 66FR, 66FL, 6
It is detected based on the detection signals from 6RR and 66RL. That is, the slip detection means 72 calculates the amount of slip by subtracting the rotation speed of the driven wheels from the rotation speed of the drive wheels. In calculating this amount of slip, in the case of engine control, the rotational speed of the driving wheel is selected to be the larger one of the left and right driving wheels, and the rotational speed of the driven wheel is the average value of the left and right driven wheels. For brake control, the rotational speed of the driven wheels is the same as for engine control, but the rotational speed of the driving wheels is the rotational speed of the left and right driving wheels when braking force to the left and right driving wheels is controlled independently of each other. are used respectively.

(Regarding the target value setting means 73) FIG. 3 is a block diagram showing a circuit for determining the target value SET for engine control and the target value SBT for brake control, and the determining parameters include vehicle speed and , the amount of accelerator depression, the steering angle, the operating state of the mode switch 71, and the road surface friction coefficient μ.

That is, in the figure, the basic value STA0 of SET and the basic value STB0 of SBT are stored in a map 81 using the road surface friction coefficient μ as a parameter (STB0>STA0). And this basic value STB0
, STA0 are respectively multiplied by the correction gain coefficient KD to obtain SET and SBT.

The correction gain coefficient KD is obtained by multiplying each gain coefficient VG, ACPG, STRG, and MODEG. The gain coefficient VG uses vehicle speed as a parameter and is stored as a map 82. The gain coefficient ACPG uses the accelerator opening degree as a parameter and is stored as a map 83. The gain coefficient STRG uses the steering wheel angle as a parameter and is stored as a map 84. The gain coefficient MODEG is manually selected by the driver.
It is stored in table 85. This table 85 provides three types: sports mode, normal mode, and safety mode.

The lower limit value SM, which will be described later, is stored as a map 91 using vehicle speed and road surface friction coefficient μ as parameters, as shown in FIG. In addition, in FIG. 4,
μ=1 is the minimum friction coefficient, and μ=5 is the maximum friction coefficient.

(Regarding the road surface friction coefficient calculation means 74) The road surface friction coefficient μ, which is the friction coefficient between the tires and the road surface, is
It is calculated based on the vehicle speed Vr and the vehicle acceleration VG.

That is, to calculate the vehicle acceleration VG,
Timer A (100 msec count) and Timer B (5
00msec count) is used. In other words, the vehicle body acceleration VG is 100 msec from the start of slip control until 500 msec has elapsed (vehicle body acceleration is not large enough).
Calculated using the following formula (1) based on the change in vehicle body speed Vr (in this example, the faster wheel speed of the front wheels 2FL and 2FR, unit: km/h) for 100 msec every sec. , after 500 msec has passed (vehicle body acceleration has sufficiently developed), the vehicle body speed V for 500 msec every 100 msec.
It is determined by the following equation (2) based on the change in r.

-(1) Formula-VG =Gk1×{Vr(k) -Vr(k-100)
}-(2) Formula-VG =Gk2×{Vr(k) −Vr(k-500)
}The above Gk1 and Gk2 are coefficients. Also, Vr(
k) is at present, Vr(k-100) is 100mse
Before c, Vr(k-500) is each vehicle speed 500 msec before.

Then, from the vehicle body acceleration VG and vehicle body speed Vr calculated as described above, the road surface friction coefficient μ is determined by three-dimensional interpolation according to the following Table 1.

[0045]

[Table 1]

(Regarding the slip determination means 75) The slip determination by the slip determination means 75 is performed by comparing the slip amount with the target values SET and SBT. That is, when the slip amount is greater than SET, it is determined that engine control is necessary, and when it is greater than SBT, it is determined that brake control is necessary.

(Regarding the control amount calculation means 76) The control amount calculation means 76 calculates the control amount based on the difference between the slip amount and the target values SET and SBT. That is, the target throttle opening (opening of the sub-throttle valve 45) TH・S required to set the target value SET is, for example, PI
- Brake force Pn (valve 32, 34, 36A, 36B) determined by PD control and necessary to reach target value SBT
, or the operation amount of 37A, 37B=duty ratio) is determined by, for example, I-PD control.

-Contents of slip control- The contents of the slip control by the TRC control means 70 are as follows:
FIG. 5 shows a focus on engine control and brake control. In the figure, the target value for the engine (target slip amount of the driving wheels) is indicated by SET, and the target value for the brake is indicated by SBT (SBT>SET).

[0049] Before time t1, no large slip has occurred in the driving wheels, so engine control is not being performed, and therefore the sub-throttle valve 45 is fully open, and the throttle opening Tn (both throttle valves 43, 45, which corresponds to the opening of the smaller throttle valve) is the main throttle opening TH·M corresponding to the amount of accelerator depression.

At time t1, the slip amount of the driving wheels reaches the engine target value SET, which is when a large slip occurs. In the embodiment, the slip control is started when the slip amount of the driving wheels exceeds SET, and at this time t1, the throttle opening reaches the lower limit control value S.
It is reduced all at once to M (feedforward control)
. Once SM is set, the opening degree of the sub-throttle valve 45 is feedback-controlled so that the slip amount of the drive wheels becomes the engine target value SET. At this time,
The throttle opening degree Tn becomes the sub-throttle valve opening degree TH·S.

[0051] At time t2, the slip amount of the driving wheels has exceeded the brake target value SBT. At this time, brake fluid pressure is supplied to the brakes 21RL and 21RR of the driving wheels, and engine control and brake Slip control is initiated by both controls. The brake fluid pressure is feedback-controlled so that the slip amount of the driving wheels becomes the brake target value SBT.

[0052] At time t3, the slip amount of the driving wheels has become less than the brake 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 conditions for ending the slip control are as follows:
This is the time when the slip amount converges to SET and the accelerator depression amount becomes zero, or the time when the main throttle opening becomes smaller than the sub-throttle opening.

-Mode Determination- When turned on, the TRC switch 78 selects a control mode in which the TRC control means 70 executes control when the slip amount of the driving wheels exceeds the SET, and when turned off, , the slip amount of the drive wheel is the above S
This is a state in which a prohibition mode is selected that prevents the TRC control means 70 from executing control even if the ET is exceeded. In addition, the cancel switch 79 is
By turning on during control execution by the control means 70, this TR
The C control means 70 is in a state in which the cancel mode is selected to temporarily suspend its control, and by turning it off, the selection of the cancel mode is canceled.

[0055] Therefore, the mode determining means 80
When the control mode is selected by the switch 78 and slip control is being executed, the cancel switch 7
9 is turned on from off, it receives the outputs of the accelerator depression amount sensor 67 and the steering angle sensor 69, and determines that the steering angle θH is equal to or greater than the predetermined value θH1 and the accelerator depression amount Acc
is greater than or equal to the predetermined value Acc1, the mode of the TRC control means 70 is switched from the control mode to the cancel mode, and the first
When the set time T1 has elapsed and the steering angle θH is substantially zero (the state where the vehicle is traveling straight), the second set time T2 is reached.
When it continues, and in the stop mode state, the steering angle θH is less than the predetermined value θH1 or the accelerator depression amount A
When cc becomes less than a predetermined value Acc1, the control mode is set.

The above θH1 and Acc1 are the steering angle and accelerator depression required for an accelerator turn. Also,
The first set time T1 is the time required for the driver to perform an accelerator turn. Also, the second set time T
2 can be set, for example, from several seconds to several minutes.

The flow of the mode determination control described above is shown in FIG.

That is, various data are input, and the TRC
If the cancel switch 79 is turned on while the switch 78 is in the control mode with the switch 78 on and slip control is in progress, the first set time T1 has elapsed and the steering angle θH has become substantially zero. The state is at the second set time T2
If the process continues, the control mode is maintained without changing to the abort mode (steps S1 to S7). Therefore,
In this case, the slip control continues regardless of whether the cancel switch 79 is turned on.

[0059] Before the first set time T1 or the second set time T2 elapses, the steering angle θH reaches the predetermined value θH1.
or more, and the accelerator depression amount Acc is the predetermined value Ac.
When it is detected that the condition is equal to or higher than c1, the control mode is switched to the cancel mode (S8, S9). In this case, the driver intends to make an accelerator turn, and the slip control is immediately stopped, thereby allowing the accelerator turn.

After switching to the abort mode, if the steering angle θH becomes less than the predetermined value θH1 or the accelerator depression amount Acc becomes less than the predetermined value Acc1, the control mode is returned to (S1
0, S7). Therefore, even if there is a mistake in operating the cancel switch 79, or even if the driver's schedule is changed after the driver selects the cancel mode, the steering angle θ
H is greater than or equal to the predetermined value θH1, and the accelerator depression amount A
Unless cc becomes equal to or higher than the predetermined value Acc1,
This prevents the vehicle from entering the abort mode, and prevents the slip control from being inadvertently aborted and causing the vehicle's running condition to become unstable. In addition, even if the cancel mode is entered, the steering angle θH or the accelerator depression amount A
When cc becomes less than a predetermined value, the mode returns to the control mode. For example, even if you make a sharp curve while depressing the accelerator after an accelerator turn, the slip control will not be canceled, and this slip control will improve the running stability of the vehicle. Alternatively, acceleration can be ensured.

Further, in step S4, if the cancel switch 79 is not turned on,
After the slip has converged, if the accelerator depression amount Acc becomes zero or the main throttle opening becomes smaller than the sub-throttle opening, the slip control is stopped (steps S11 to S14).

[0062] In the above embodiment, the TRC switch 78
Although a separate cancel switch 79 is provided for selecting control mode and prohibition mode and selecting cancel mode, separate push switches for each mode may be provided, or for selecting control mode, prohibition mode, and cancel mode. A sliding type or rotary type switch means having each contact point may be provided.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the invention.

[Figure 1] Overall configuration diagram of vehicle traction control device

[Figure 2] Block diagram of control system

[Figure 3] Circuit diagram for determining slip control target value

[
Figure 4: Map diagram for setting the lower limit value SM

[Figure 5]
Slip control time chart

[Figure 6] Flow diagram of mode decision control

[Explanation of symbols]

2RL, 2RR Drive wheel 67 Accelerator depression amount sensor 69 Rudder angle sensor 70 TRC control means 72 Slip detection means 73 Target value (threshold value) setting means 78 TRC switch (for selecting control mode and prohibition mode) 79 Cancel switch (for selecting cancel mode) )
80 Mode determining means

Claims (4)

[Claims] 1. A traction control device for a vehicle, comprising control means for controlling the drive of the drive wheels so that when the amount of slip of the drive wheels relative to the road surface exceeds a predetermined threshold value, the amount of slip becomes a target value. a control mode switch for selecting a control mode for causing the control means to execute control when the amount of slip of the driving wheels exceeds the threshold; , a prohibition mode switch for selecting a prohibition mode that prevents the control means from executing control; and a prohibition mode switch for selecting a prohibition mode that causes the control means to temporarily stop the control while the control means is executing the control. 1. A traction control device for a vehicle, comprising: an abort mode switch for controlling the mode; and mode determining means for determining a mode of the control means based on turning on each of the mode switches. 2. A steering angle detecting means for detecting a steering angle, and an accelerator depression amount detecting means for detecting an accelerator depression amount, and the mode determining means is configured to switch the abort mode switch from a state in which the control mode switch is turned on. When the steering wheel is turned on, based on the steering angle detected by the steering angle detection means and the accelerator depression amount detected by the accelerator depression amount detection means, the steering angle is equal to or more than a predetermined value and the accelerator depression amount is a predetermined value. 2. The traction control device for a vehicle according to claim 1, wherein the mode of the control means is set to an abort mode when the above is the case. 3. The mode determining means changes the mode of the control means when the abort mode switch is turned on from a state in which the control mode switch is turned on and a set time has elapsed since the abort mode switch was turned on. The traction control device for a vehicle according to claim 1, wherein the traction control device is in a control mode. 4. A steering angle detection means for detecting a steering angle, and a mode determining means, when a control mode switch is turned on and a stop mode switch is turned on, the mode determination means is configured to detect a steering angle when a control mode switch is turned on and a stop mode switch is turned on. When the first set time has elapsed and the steering angle detected by the rudder angle detection means continues to be substantially zero for a second set time, the mode of the control means is set to the control mode. Item 1. The traction control device for a vehicle according to Item 1.