JPH0711988A - Traction control method - Google Patents

Abstract

PURPOSE:To execute traction control according to the will of a driver by a method wherein a parameter responding to an idling factor or an idling amount based on a car body speed by the car wheel speed of a driven wheel and the wheel speed of a drive wheel is changed according to the magnitude of the opening of an accelerator. CONSTITUTION:An ECU (control unit) 22 for an ABS (antiskid control system)/TRC (traction control) is caused to decelerate an engine through control of a motor 21 for a governor link based on a pedaling amount of an accelerator pedal 23, i.e., a detecting signal from an accelerator sensor 27 to detect the opening of an accelerator. Simultaneously, a plurality of TRC valves 18 and 19 are controlled. In this case, the ECU 22 is caused to set a parameter according to an idling factor or an idling amount based on the wheel speed of a driven wheel and the wheel speed of a drive wheel. The parameter is changed according to the magnitude of the opening of an accelerator. This constitution executes traction control according to the will of a driver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction control method for suppressing idling of drive wheels when a vehicle such as an automobile starts or suddenly accelerates, and in particular, traction by engine deceleration in consideration of a driver's intention. The present invention relates to a traction control method for controlling.

[0002]

2. Description of the Related Art In recent years, in automobiles, the power loss of the engine is reduced as much as possible when the drive wheels tend to idle, and the drive force of the drive wheels is more effectively transmitted to the road surface to effectively propel the vehicle. Traction control (hereinafter, TRC) that adjusts the driving force of the driving wheels
System) is being developed.

As such a TRC system, there is an ABS / TRC system as shown in FIG. 5, for example, and this ABS / TRC system is an anti-skid brake that adjusts the braking force in order to prevent the locking wheels from being locked during braking. Control (hereinafter also referred to as ABS) system and TR
This is a system in which C and C are integrated together.

The ABS / TRC system comprises wheel speed sensors 3 and 4 for detecting wheel speeds of left and right front wheels 1 and 2 which are non-driving wheels, a modulator 5 for adjusting brake pressure of the front wheels 1 and 2, and front wheels 1 and 2 Brake actuator 6 that generates braking force, wheel speed sensors 9 and 10 that detect the wheel speed of the left and right rear wheels 7 and 8 that are drive wheels, and modulators 11 and 12 that adjust the brake pressure of the rear wheels 7 and 8, respectively. , Rear wheel 7,
8, brake actuators 13 and 14 for generating braking force, respectively, a dual brake valve 16 which is controlled to be opened and closed by a brake pedal 15, compressed air in an air tank 17 which is opened at the time of traction control, and modulators 11 of left and right rear wheels 7 and 8. Traction solenoid valve (hereinafter TRC
(Also called a valve) 18,19, a motor 21, which is a governor actuator that operates a governor link that changes and sets the lower limit of the number of revolutions of the engine 20, each modulator 5, 1
1 and 12, ABS / TRC control unit (hereinafter, also referred to as ABS / TRC ECU) 22 for controlling the traction electromagnetic valves 18 and 19 and the motor 21 are provided. In the figure, 23 is an accelerator pedal.

The ABS / TRC system shown in FIG.
Wheel speed sensors 3, 4, 9 and 10 are provided for each of the left and right front and rear wheels, and a modulator 5 is provided to the left and right front wheels 1 and 2.
For one in total and one for each of the left and right rear wheels 7, 8 for a total of 3
It is a 4-sensor, 3-channel control system provided individually.

In the ABS / TRC system thus constructed, the wheel speed signals from the wheel speed sensors 3, 4, 9 and 10 are sent to the ABS / TRC ECU 22. During braking, the ABS / TRC ECU 22 calculates based on these wheel speed signals, and if it is determined that the wheels tend to lock based on the calculation results, the ABS / TRC
The RC ECU 22 outputs a control signal to the modulators 5, 11, 12 corresponding to the wheels that tend to lock. As a result, the modulators 5, 11, 12 adjust the brake pressures of the brake actuators 6, 13, 14 so as to eliminate the lock tendency of the wheels. Thus, A
The BS / TRC ECU 22 performs anti-skid brake control so that the wheel lock tendency is eliminated when the wheel lock tendency tends to occur during braking.

Further, when the propulsive force of the vehicle is increasing at the time of starting the vehicle or during sudden acceleration, the ABS / TRC ECU 22 calculates based on the wheel speed signals from the wheel speed sensors 3, 4, 9 and 10, and If it is determined from the calculation result that the rear wheels 7 and 8 that are the drive wheels tend to idle, this ABS / TRC ECU
Reference numeral 22 denotes modulators 11 and 12 and traction electromagnetic valves (hereinafter,
The control signal is also output to the TRC valves 18 and 19 and the control signal is output to the motor 21 that operates the governor link.

In this case, the determination of the slipping tendency of the rear wheels 7, 8 which is the basis of the output timing of the control signal from the ABS / TRC ECU 22 to the TRC valves 18, 19 is made by the difference between the wheel speeds of the left and right rear wheels 7, 8. Is greater than a predetermined value, it is determined that the rear wheel having the higher wheel speed tends to idle. That is, when the difference between the wheel speeds of the left and right rear wheels 7, 8 becomes larger than a predetermined value, the rear wheel 7, 8 having the larger wheel speed is used.
It is judged that there is a tendency to slip. Actually, the wheel speed selected by the select high of the wheel speeds of the left and right front wheels 1 and 2 which are non-driving wheels is determined as the vehicle body speed (hereinafter, also referred to as vehicle speed),
The difference between the vehicle speed and the wheel speed of the rear wheel on the low μ side of the road friction coefficient (hereinafter, also referred to as μ) of the left and right rear wheels 7 and 8 is used to determine the idling tendency of one of the rear wheels 7 and 8. ing.

The determination of the slipping tendency of the rear wheels 7 and 8 which is the basis of the output timing of the control signal from the ABS / TRC ECU 22 to the motor 21 is based on the vehicle speed and the wheel speeds of the left and right rear wheels 7 and 8 described above. When the difference from the average exceeds a predetermined value, it is determined that the left and right rear wheels 7, 8 tend to slip.

The TRC valves 18 and 19 are turned on and opened by a control signal from the ABS / TRC ECU 22, and the compressed air from the air tank 17 is transferred to the traction electromagnetic valve 1.
8, 19, through the double check valves 24, 25 and the modulators 11, 12, the brake actuator 13,
The rear wheels 7 and 8 which are supplied to 14 and tend to idle are braked. By the braking of the rear wheels 7 and 8, the rotational driving force of the rear wheels 7 and 8 is suppressed, and as a result, the idling tendency of the rear wheels 7 and 8 which tends to slip is eliminated.

A TRC shown in FIG. 6 is an example of the TRC based on the braking of the driving wheels. In FIG. 6, at time t ₀ , the TRC is in the non-controlled state, the brake pressure is not generated, and the rear wheels 7 and 8 are not braked. At time t ₁ , the ABS / TRC ECU 22 determines that the wheel speed of the rear wheels 7 and 8 on the low μ side becomes higher than the set threshold value with respect to the vehicle speed, and the rear wheels 7 and 8 on the low μ side idle. When it is determined that the tendency has occurred, a control signal is output to the TRC valves 18 and 19. By this control signal from the ABS / TRC ECU 22, the TRC valves 18, 19 of the rear wheels 7, 8 on the low μ side are turned on.
Then, the brake is applied to the rear wheels 7, 8 on the low μ side, that is, the wheels that tend to idle. Thus, TRC by braking is started. Then, the modulators 11 and 12 are controlled according to the idling of the drive wheels to increase, maintain, and reduce the brake pressure. For a certain period after the start of braking, a relatively long build pulse is output to the holding solenoid valves (not shown) of the modulators 11 and 12 to remove the hysteresis of the braking system, and the holding solenoid valves are turned on / off. Repeat off. At time t ₂ , the pressure gradually increases. Several types of this slow pressure increase rate are set according to the idling amount of the drive wheels, that is, the size of the road surface μ. When the idling tendency is decreasing, the holding solenoid valves of the modulators 11 and 12 are turned on at time t ₃ , and
By turning off or briefly turning on the exhaust electromagnetic valves (not shown) of the modulators 11 and 12, the brake pressure is held or reduced, and the degree of recovery of the wheels is monitored. The vehicle starts in this state. When the idling amount becomes considerably small, time t
_The brake pressure is further reduced at ₄ , and when the idling amount of the rear wheels 7, 8 gradually increases again due to the depressurization of the brake pressure, after time t _{5, the} brake pressure is adjusted by gradually increasing the idling tendency. To do. Subsequently, it carried out, the reduced pressure of the same brake pressure at time t ₄ in the holding or reduced and the time t ₇ the same brake pressure at time t ₃ at time t ₆ according to slipping tendency state of the drive wheels. When the slipping tendency of the rear wheels 7 and 8 is eliminated, T at a time t ₈
RC valves 18 and 19 are turned off, and air tank 17
The supply of air from is stopped. In that case, the modulators 11 and 12 are continuously operated to discharge the residual pressure in the piping system.
The modulators 11 and 12 are turned off at time t ₉ after a certain time has elapsed.
After FF, TRC is completed. TRC by this braking
Is effective when μ of the road surface of each of the left and right rear wheels 7 and 8 is not uniform.

On the other hand, the control signal from the ABS / TRC ECU 22 rotates the motor 21 to adjust the governor link of the engine 20, and the engine 20 is decelerated. Due to the deceleration of the engine 20, the rotational driving force of the rear wheels 7, 8 is suppressed, and as a result, the rear wheels 7, 8 which tend to idle.
The tendency of slipping will be eliminated. Also, the rear wheels 7,8
Even during TRC due to braking of the engine 20, the deceleration control of the engine 20 is performed, and the lower limit value of the rotational speed of the engine 20 is set to a slightly larger lower limit value during TRC so that engine stall does not occur during TRC due to braking of the rear wheels 7 and 8. Change and adjust.

As a TRC based on such engine deceleration, there is a TRC shown in FIG. In TRC by engine deceleration shown in FIG. 7, when the rear wheels 7 and 8 tend to idle after the start of the vehicle at time t ₀ , ABS / TR
The C ECU 22 detects this and outputs a control signal to the motor 21 at time t ₁ . As a result, the deceleration of the engine 20 starts with a slow deceleration. However, at time t
_When the average drive shaft speed of the left and right rear wheels 7 and 8 exceeds a permissible level at 2, the engine 20 is decelerated at full deceleration. When the idling tendency decreases, the engine 2 starts at time t _3.
Release the 0 deceleration gradually. That is, the engine 20 is accelerated by gentle acceleration. In that case, the engine 20 is rapidly accelerated according to the amount of idling and the deceleration of the drive shaft (the average of the deceleration of the left and right rear wheels 7, 8). In this state, the rear wheels 7,
When the idling tendency of only one side of 8 rises again, T at time t ₄
Modulator 1 by turning on one of RC valves 18 and 19
One of the wheels 1 and 12 is controlled to brake one of the rear wheels 7 and 8 which tend to idle, and the engine deceleration is started.
As a result, the tendency of one of the rear wheels 7, 8 which tends to slip is reduced, but when the tendency of the other of the rear wheels 7, 8 also becomes less, the engine 20 is abruptly accelerated at time t ₅ to avoid engine stall. To do. When the idling tendency of the rear wheels 7, 8 increases again due to the sudden acceleration of the engine 20, the engine 20 is rapidly decelerated again at the time t ₆ . In that case, the engine 20 is slowly decelerated depending on the acceleration of the drive shaft (the average of the accelerations of the left and right rear wheels 7, 8) and the idling amount. When the wheel speeds of the rear wheels 7 and 8 tend to decrease, the vehicle gradually accelerates at time t ₇ .
This slow acceleration is calculated based on the internal integrated value of the deceleration instruction value, and the internal integrated value is calculated by the wheel behavior and the previous deceleration instruction value. Thus, TRC is performed until the tendency of the rear wheels 7, 8 to slip is eliminated. The TRC based on the engine deceleration is effective when the road surfaces μ of the left and right rear wheels 7 and 8 are equal to each other.

In this way, the ABS / TRC ECU
The reference numeral 22 performs TRC by braking and TRC by engine control so that the idling tendency of the rear wheels 7 and 8 as driving wheels is eliminated. Also, ABS / TRC
The ECU 22 lights the traction pilot lamp 26 during the TRC to notify the driver that the TRC is being performed.

[0015]

By the way, when a vehicle such as a commercial vehicle having a large carrying weight travels on a long uphill road,
When the drive wheels are made to converge to the proper slip ratio by RC, the rotational driving force of the drive wheels is reduced, so the gradeability of the vehicle is reduced and the vehicle speed is gradually reduced while traveling on a long slope. Sometimes. Therefore, even if the driver tries to accelerate by depressing the accelerator pedal greatly, the TR
Since the engine output is suppressed by C, the engine is not accelerated and the rotational driving force of the drive wheels does not increase.

As described above, when a vehicle having a large loaded weight is run on a long uphill road, the vehicle cannot be driven as the driver intends, which may hinder the running of the vehicle. There is.

The present invention has been made in view of the above problems, and an object thereof is to perform TRC when a vehicle such as a commercial vehicle having a large carrying weight is run on a long uphill road. It is also to provide a traction control method that allows the vehicle to drive as the driver wishes.

[0018]

In order to solve the above-mentioned problems, the invention of claim 1 detects each wheel speed of a non-driving wheel and a driving wheel of a vehicle, and determines the wheel speed of the non-driving wheel. The vehicle speed is calculated based on the vehicle speed and the wheel speed of the drive wheels, and it is determined whether or not the drive wheels tend to idle based on the idling ratio or the idling amount set by the wheel speeds of the drive wheels. When it is determined that the idling tendency has occurred, in the traction control method of adjusting the rotational driving force of the drive wheels by engine deceleration so that the idling tendency is eliminated, an instruction for the engine deceleration corresponding to the idling amount or the idling ratio is provided. It is characterized in that a parameter for determining the value is set and the parameter is changed according to the magnitude of the accelerator opening.

According to a second aspect of the present invention, a predetermined number of the parameters are provided, and these parameters correspond to the same idling amount or idling ratio as the accelerator opening increases. It is characterized in that the magnitude is set so that the deceleration instruction value becomes small.

Further, the invention of claim 3 is characterized in that the parameter is set so that the idling amount or idling ratio and the instruction value of the engine deceleration have a linear relationship. Further, the invention of claim 4 is characterized in that the parameter is set such that the idling amount or idling ratio and the instruction value of the engine deceleration have a non-linear relationship.

[0021]

In the present invention thus constructed, when the idling tendency of the drive wheels of the vehicle is detected, the engine deceleration value is determined by a parameter according to the idling amount or idling ratio of the drive wheels, and the determined engine deceleration is determined. Traction control by engine deceleration is performed based on the value. In that case, the parameter changes in accordance with the accelerator depression amount of the driver, that is, the magnitude of the accelerator opening, so that the engine deceleration value determined by the parameter takes the accelerator opening into consideration. That is, the allowable slip ratio changes according to the size of the accelerator opening.

As a result, the traction control by decelerating the engine is performed according to the driver's intention, and TRC is performed when a vehicle such as a commercial vehicle having a large carrying weight is run on a long uphill road. However, the vehicle will run according to the driver's will.

In particular, according to the second aspect of the invention, a parameter corresponding to the magnitude of the accelerator opening is selected from a predetermined number of parameters, and the idling amount or idling ratio is determined based on the selected parameter. The corresponding engine deceleration value is determined. In that case, if the accelerator opening is large, the engine deceleration instruction value corresponding to the same idling amount or idling ratio becomes small, and if the accelerator opening is small, the engine deceleration instruction value corresponding to the same idling amount or idling ratio becomes smaller. growing.

That is, when the accelerator opening is large,
Since it is possible to determine that the driver is depressing the accelerator pedal largely because the load on the driving wheels is large, the instruction value for engine deceleration is made small and the allowable slip ratio is made large. As a result, when the driver depresses the accelerator pedal greatly during TRC on the uphill road of the vehicle,
The vehicle will not slow down gradually and will be able to travel on an uphill road or the like as the driver wishes.

When the accelerator opening is small, it can be determined that the driver is stepping on the accelerator pedal a little because the load acting on the drive wheels is small or the driver wants to drive carefully. The deceleration instruction value is increased and the allowable slip ratio is decreased. As a result, during TRC on the uphill road of the vehicle, when the driver depresses the accelerator pedal slightly, the idling of the drive wheels becomes small, and the vehicle can run on the uphill road while performing the TRC as the driver desires. become.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of a traction control method according to the present invention, FIG. 2 is a diagram for showing an example of a system for carrying out this embodiment, and FIG. 3 is a flow of processing in this embodiment. It is a figure explaining.
Since the ABS / TRC system used in this embodiment is the same as the above-described conventional ABS / TRC system, this embodiment will be described using the same reference numerals as those in the conventional ABS / TRC system.

In the present embodiment, the driver's intention to accelerate is judged based on the amount of accelerator opening by the driver's depression of the accelerator pedal 23, and the strength of the judged driver's intention to accelerate, that is, The allowable slip ratio changes according to the magnitude of the accelerator opening. Therefore, in the present embodiment, as shown in FIG. 1, a predetermined number of parameters for determining the engine deceleration instruction value for the slip ratio (corresponding to the idling ratio of the present invention) are set according to the magnitude of the accelerator opening. ing. In the example shown in FIG. 1, from the case where the accelerator opening is small to the case where it is large, 4
Two parameters (1) to (4) are set. In this case, the smaller the accelerator opening, the larger the parameter inclination, and the larger the accelerator opening, the smaller the parameter inclination. That is, the parameters are set such that the engine deceleration instruction value decreases as the accelerator opening increases with the same slip ratio. Further, these parameters are set such that the slip ratio and the instruction value for engine deceleration are in a linear relationship.

The reason for setting the parameters in this way is as follows.
When the accelerator opening is small, it is considered that the load acting on the drive wheels is small, or the driver wants to drive carefully.Therefore, the allowable slip ratio should be suppressed to a small value so that the drive wheels do not slip. This is because the vehicle can travel on an uphill road or the like while performing the TRC according to the intention of the driver. Also, when the accelerator opening is large, the load acting on the drive wheels is large and it is possible that the vehicle gradually decelerates. Therefore, the allowable slip ratio is increased and the rotational driving force of the drive wheels is increased. This is because when the driver depresses the accelerator pedal a lot during TRC on the uphill road, the vehicle can travel on the uphill road as the driver wishes without decelerating.

It should be noted that the parameters may be provided in any suitable number other than four. Although the horizontal axis represents the slip ratio in FIG. 1, the horizontal axis may represent the slip amount (corresponding to the idling amount of the present invention) instead of the slip ratio.

An accelerator sensor 27 such as a potentiometer is provided on the accelerator pedal 23 in order to detect the amount of depression of the accelerator pedal 23, which is the accelerator opening degree, as shown in FIG. This accelerator sensor 27
Is an ABS / TRC ECU that outputs an accelerator opening signal having a magnitude proportional to the amount of depression of the accelerator pedal 23.
22 is output. The ABS / TRC ECU 22 determines an engine deceleration value corresponding to the magnitude of the accelerator opening signal and outputs an engine deceleration instruction signal to the motor 21 based on the determined engine deceleration value. In response to the engine deceleration instruction signal, the motor 21 is driven to rotate the governor link and the engine is decelerated.

A procedure for changing the allowable slip ratio based on the magnitude of the accelerator opening will be described with reference to the processing flow shown in FIG. As shown in FIG. 3, first, after initialization is performed in step ST1,
In step ST2, the wheel speeds of the left and right front wheels 1 and 2 that are non-driving wheels and the left and right rear wheels 7 and 8 that are driving wheels are determined based on the wheel speed signals from the wheel speed sensors 3, 4, 9, and 10. In addition to being calculated, the estimated vehicle body speed is calculated by the select high of the wheel speeds of the left and right front wheels 1 and 2 in step ST3. Next, in step ST4, it is determined whether or not the ABS control start condition is satisfied. When it is determined that the ABS control start condition is not satisfied, it is determined in step ST5 whether the brake TRC control (hereinafter also referred to as brake TRC) start condition is satisfied. In the determination of the start condition of the brake TRC control, it is determined whether or not the difference between the wheel speeds of the left and right rear wheels 7, 8 is equal to or more than a predetermined value for a predetermined time. Actually, it is judged whether or not the difference between the estimated vehicle speed and the wheel speed of the rear wheels 7 and 8 on the low μ side continues to be a predetermined value or more for a predetermined time, and the estimated vehicle speed and the low μ side When the difference between the wheel speeds of the rear wheels 7 and 8 is equal to or more than a predetermined value for a predetermined time, low μ
It is determined that the rear wheels 7, 8 on the side are in a tendency to slip.

If it is determined that the condition for starting the brake TRC control is not satisfied, it is determined in step ST6 whether or not the condition for starting the TRC control by engine deceleration (hereinafter also referred to as engine TRC control) is satisfied. In determining the start condition of the engine TRC control, the difference between the estimated vehicle speed and the rotational speed of the drive shaft that is the average of the wheel speeds of the left and right rear wheels 7 and 8 (ie, the slip amount) or the slip amount is calculated as the estimated vehicle speed. It is determined whether or not the slip ratio divided by is greater than or equal to a predetermined value for a predetermined time. When the slip amount or the slip ratio is equal to or more than the predetermined value for the predetermined time, it is determined that the left and right rear wheels 7 and 8 are in the tendency to slip.

When it is determined that the engine TRC control start condition is satisfied, the engine TRC control is started, and first in step ST7, an accelerator opening signal is input from the accelerator sensor 27 to the ABS / TRC ECU 22. Next, in step ST8, ABS / TRC
The ECU 22 calculates the allowable slip ratio or the allowable slip amount based on the magnitude of the accelerator opening signal. Specifically, among the parameters (1) to (4) for determining the engine deceleration instruction value for the slip ratio shown in FIG. 1, the parameter corresponding to the magnitude of the accelerator opening is selected. In the case of the slip amount, the horizontal axis shown in FIG. 1 is the slip amount instead of the slip ratio.

Next, in step ST9, the engine deceleration value with respect to the slip ratio or slip amount is calculated based on the selected parameter, and subsequently in step ST10, the engine is decelerated based on the engine deceleration value calculated by the motor 21. Then, the engine deceleration instruction signal is output to the motor 21. In this way, in the engine TRC control of this embodiment, the engine is decelerated according to the accelerator opening.

FIG. 4 is a diagram showing another example of a system for carrying out the traction control method of the present invention.
As shown in FIG. 4, a governor controller (hereinafter also referred to as a governor ECU) 28 is provided in the example of this system. The governor ECU 28 has an accelerator sensor 27.
Is connected, and an accelerator opening signal is input from the accelerator sensor 27. In addition, the governor ECU 28 is connected to the ABS / TRC ECU 22 and sends the accelerator opening signal to the ABS / TRC EC
ABS / TRC ECU2 while sending to U22
2 receives the engine deceleration instruction signal. Further, the governor ECU 28 drives and controls the motor 21 that rotates the governor link based on the engine deceleration instruction signal.

In the case of a vehicle equipped with an electronic governor engine, the governor ECU 28 may be an electronic governor ECU, and the motor 21 may correspond to a stepping motor or an injector. Further, in the above-described embodiment, the parameters are set so that the slip ratio and the engine deceleration instruction value have a linear relationship, but the present invention is not limited to this, and the present invention is not limited to the slip ratio and the engine deceleration instruction value. It is also possible to set the parameters so that has a non-linear relationship.

Further, when a controller of another system is interposed therebetween, the accelerator opening signal and the engine deceleration instruction signal to the ABS / TRCECU 22 are implemented by serial communication or pw signal. Further, the accelerator sensor 27 does not necessarily have to output an accelerator opening signal having a magnitude proportional to the amount of depression of the accelerator pedal 23, and operates when the depression amount of the accelerator pedal 23 reaches a predetermined amount. It may be a simple switch.

Further, in the above-mentioned embodiment, the case where the ABS system and the TRC system are incorporated together has been described, but the present invention describes that the TRC system is the ABS.
When provided separately from the system or T
It is also applicable when only RC is provided.

[0039]

As is apparent from the above description, according to the traction control method of the present invention, the traction control by the engine deceleration can be performed according to the intention of the driver. When a vehicle having a large carrying weight such as a vehicle is run on a long uphill road, the vehicle can run as the driver intends even if TRC is performed.

In particular, according to the second aspect of the present invention, since the allowable slip ratio is increased when the accelerator opening is large, when the driver fully depresses the accelerator pedal during TRC on the uphill road of the vehicle. Thus, the vehicle can be driven uphill or the like according to the driver's intention without decelerating the vehicle. Further, when the accelerator opening is small, the allowable slip ratio is made small. Therefore, when the driver depresses the accelerator pedal a little at the time of TRC on the uphill road of the vehicle, the idling of the drive wheels can be made small and the vehicle It becomes possible to drive on an uphill road and the like while performing TRC according to the driver's intention.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of a traction control method according to the present invention.

FIG. 2 is a diagram showing an example of a system for carrying out this embodiment.

FIG. 3 is a diagram illustrating a processing flow in this embodiment.

FIG. 4 is a diagram showing another example of a system for carrying out this embodiment.

FIG. 5 is a diagram showing a conventional ABS / TRC system.

FIG. 6 is a diagram illustrating a TRC using a conventional brake.

FIG. 7 is a diagram illustrating a conventional TRC due to engine deceleration.

[Explanation of symbols]

1, 2 ... Left and right front wheels (non-driving wheels), 3, 4.9, 10 ... Wheel speed sensor, 5, 11, 12 ... Modulator for anti-skid control, 6, 13, 14 ... Brake actuator,
7, 8 ... Left and right rear wheels (driving wheels), 15 ... Brake pedal, 16 ... Dual brake valve, 17 ... Air tank, 18, 19 ... Traction electromagnetic valve (TRC valve), 20 ... Engine, 21 ... Motor, 22 ... ABS /
TRC control unit (ABS / TRC EC
U), 23 ... accelerator pedal, 24, 25 ... double check valve, 26 ... traction pilot lamp, 2
7 ... Accelerator sensor, 28 ... Governor controller (governor ECU)

Claims (4)

[Claims] 1. A vehicle speed of each of a non-driving wheel and a driving wheel of a vehicle is detected, a vehicle speed is obtained based on the wheel speed of the non-driving wheel, and the vehicle speed and the wheel speed of the driving wheel are calculated. When it is determined that the drive wheels have a slip tendency based on the set slip ratio or the slip amount, and when it is determined that the drive wheels have a slip tendency, the engine is decelerated to drive the drive wheels to rotate. In a traction control method of adjusting the force so that the tendency to slip is eliminated, a parameter for determining an instruction value for the engine deceleration corresponding to the slip amount or the slip ratio is set, and this parameter is set to a large accelerator opening degree. A traction control method characterized in that it is changed according to the height. 2. A predetermined number of the parameters are provided, and the instruction value of the engine deceleration corresponding to the same idling amount or idling ratio becomes smaller as the accelerator opening becomes larger. The traction control method according to claim 1, wherein the size is set so that 3. The traction control method according to claim 1, wherein the parameter is set so that the idling amount or idling ratio and the instruction value of the engine deceleration have a linear relationship. . 4. The traction control method according to claim 1, wherein the parameter is set so that the idling amount or idling ratio and the instruction value of the engine deceleration have a non-linear relationship. .