JPH0958448A - Traction control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a traction control system capable of keeping the slip ratio of a wheel in an ideal state even under various circumstances. SOLUTION: Constitution is made by providing an ASR actuator 2 for controlling a slip on an driving wheel, a mode selecting switch 3 for selecting an operating mode for controlling the slip on the driving wheel, and an ASR control unit 4 for assuming the operating control of the ASR actuator 2 and for changing over the operating characteristics of the ASR actuator 2 by corresponding to the set of the mode selecting switch 3. The slip control characteristics of the driving wheel are changed by means of operating mode selection afforded by the mode selecting switch 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction control system for controlling wheel slip.

[0002]

2. Description of the Related Art Recently, drive wheels slip by controlling the output of the engine for the purpose of improving start / acceleration and turning stability on slippery road surfaces, and further improving maneuverability. Vehicles equipped with a traction control system that keeps the power consumption within an appropriate range are increasing.

As such a traction control system, an ASR actuator for controlling the slip of the drive wheel and the operation of the ASR actuator so that the slip of the drive wheel falls within a predetermined range have been heretofore known. Which is the computer that controls the AS
An R control unit and an on / off switch for turning the ASR control unit into an operating state or a non-operating state are provided, and the ASR control unit includes a speed difference between a non-driving wheel and a driving wheel. There is known a configuration in which the operation of the ASR actuator is controlled so that the slip ratio of the driving wheels calculated from the above can be within one predetermined ideal range.

[0004]

However, the ideal slip ratio is a variable that varies depending on road surface conditions and driving conditions. For example, in general, when accelerating on a rough road, the acceleration force tends to be stronger when moderate slippage occurs on the drive wheels, and in such a case, the ASR is simply performed so that the slip ratio becomes lower. If the actuator is controlled, a problem of deterioration of acceleration will occur.

Therefore, conventionally, for example, a situation in which the control of the slip ratio is most required (for example, when the road surface is a slippery flat surface such as a frozen road or a snow-covered road)
And improve the start / acceleration under the assumed conditions,
Alternatively, in order to improve turning stability and maneuverability, one ideal slip ratio range is set and the slip ratio of the drive wheels is maintained within the ideal slip ratio range. While setting the control characteristics in the ASR control unit, the original purpose of the traction control system may not be fully achieved when driving under conditions other than expected, so the driver operates the system with the on / off switch. Off
It is considered to be used.

However, in such a measure, control of the slip ratio can improve the starting / accelerating property, the turning stability, and the maneuverability, among other various situations. There was a problem that the system could be effectively used only in the case of a department.

[0007] Therefore, an object of the present invention is to solve the above-mentioned problems, and it is possible to flexibly respond to changes in conditions such as road conditions and driving conditions, and to adjust the slip ratio of the wheel in various situations. It is an object of the present invention to provide a traction control system capable of maintaining an ideal state and improving starting / accelerating performance, turning stability, and maneuverability.

[0008]

The above object of the present invention is to provide an ASR actuator for controlling slip of a driving wheel, a mode selection switch for selecting an operation mode for controlling slip of the driving wheel, and the ASR actuator. A for controlling the operation and switching the operation characteristic of the ASR actuator according to the setting of the mode selection switch A
The present invention is achieved by a traction control system characterized in that a structure including an SR control unit is provided, and the characteristics of drive wheel slip control can be changed by selecting an operation mode by the mode selection switch.

In the above traction control system, the ASR control unit is
The above object can be achieved even if the configuration is such that a plurality of operation modes are realized by changing the threshold value serving as a reference for controlling the ASR actuator.

Further, in the above traction control system, the object for setting the threshold value may be a velocity or acceleration detected from the behavior of the non-driving wheels.
The above object can be achieved.

Further, in the above traction control system, the mode selection switch and the ASR control unit have different standard operation modes as the operation modes of the ASR actuator, and the standard operation mode is different in threshold value as a control reference. Even if one or more operation modes are prepared and the standard operation mode is initialized immediately after the engine of the vehicle is started, the above object can be achieved.

[0012]

According to the above configuration of the present invention, if each operation mode selectable by the mode selection switch is made to correspond to the road surface condition or the driving condition in which the ideal slip ratio is different, the road surface condition or the driving condition is It is possible to flexibly deal with the change of the situation by switching the operation mode according to the change of the situation such as.

Further, by adopting a configuration in which a plurality of operation modes are realized by changing a threshold value which is a reference for controlling the ASR actuator, it is easy to equip a large number of operation modes having different slip ratio ranges to be controlled. become.

Further, the mode selection switch and AS
As the operation mode of the ASR actuator, the R control unit is provided with a standard operation mode and one or more operation modes in which a threshold serving as a control reference is different from the standard operation mode. If the standard operation mode is initialized, the road conditions and driving conditions that are relatively easy to encounter are made to correspond to the standard operation mode, thereby reducing the number of times the driver operates the mode selection switch, and It is possible to enjoy the effect of controlling the slip ratio while reducing the burden on the person.

[0015]

1 to 3 show an embodiment of a traction control system according to the present invention. FIG. 1 is a block diagram showing a schematic configuration of a traction control system 1 of the embodiment, and FIG. FIG. 3 is an explanatory diagram showing a method of setting each operation mode in the traction control system 1, and FIG.
6 is a flowchart showing the operation of the first embodiment.

As shown in FIG. 1, the traction control system 1 of this embodiment includes an ASR actuator 2 for controlling the slip of the drive wheels and a mode selection switch for selecting an operation mode for controlling the slip of the drive wheels. 3 and the control of the operation of the ASR actuator 2, and the A
The configuration is provided with an ASR control unit 4 that switches the operation characteristics of the SR actuator 2, and the characteristics of the slip control of the drive wheels can be changed by the operation mode selection by the mode selection switch 3.

Here, the ASR actuator 2 is
It may be either one that controls the output of the engine or one that controls the braking force on the drive wheels. Further, it may be of a type in which the braking force control for the driving wheels is performed in parallel with the output control of the engine. Actuators that control the braking force applied to the drive wheels include those that control the ignition timing of the engine, those that cut off the supply of fuel, and those that control the opening of the throttle. In addition, as an actuator that controls the braking force applied to the driving wheels, there is an actuator that controls the hydraulic pressure for braking.

The mode selection switch 3 is a manual switch installed in the driver's seat, and has n contact points M ₁ , M ₂ ... M _n corresponding to n operation modes and the operation of the system is stopped (OFF). The contact Q to be activated and the mover P to perform the mode setting by switching the connection to each of these contacts are provided.

The ASR control unit 4 detects an I / O section 5 which receives an operation mode signal selected from the mode selection switch 3 and an operation mode selected via the I / O section 5, The control circuit (CPU) 6 controls the operation of the ASR actuator 2 according to the selected operation mode. The control circuit 6 uses the A
A plurality of operation modes are realized by changing the threshold value that serves as a reference for controlling the SR actuator 2. More specifically, in the case of this embodiment, as shown in FIG. 2, the target for setting the threshold is the speed f ₁ of the non-driving wheels, for example, a constant speed ΔV ₁ higher than the speed f ₁ of the non-driving wheels. A standard operation mode m ₁ in which control is started when the speed of the driving wheel becomes high, and an operation mode m in which control is started when the speed of the driving wheel becomes higher by a constant speed ΔV ₂ than the speed f ₁ of the non-driving wheel. _2, the operation mode m ₃ than the rate f ₁ of the non-driven wheel starts control when the high speed only the drive wheel constant velocity [Delta] V _3, etc. are sequentially set.

The speed difference ΔV ₁ with respect to the speed f ₁ of the non-driving wheels,
_{ΔV 2, ΔV 3 ..., ΔV} n is a threshold for starting the control, when the speed of the drive wheel, which reaches the speed difference of the corresponding, A
This means that the slip ratio control operation by the SR actuator 2 is started. For example, when the contact M ₂ is selected by the mode selection switch 3 to select the operation mode m ₂ , the ASR actuator 2 is driven in the range where the speed difference between the driving wheel and the non-driving wheel exceeds ΔV _2. ,
Engine output control and braking force control are performed so that the speed difference between the driving wheel and the non-driving wheel is maintained at ΔV ₂ . It should be noted that the speed differences ΔV ₁ , ΔV ₂ , ΔV _3, ..., ΔV _n have the relationship of the following equation (1). ΔV ₁ <ΔV ₂ <ΔV ₃ <... <ΔV _n (1) The above thresholds ΔV ₁ , ΔV ₂ , ΔV ₃ ..., ΔV _n correspond to road surface conditions and driving conditions that require slip ratio control. Are selected.

In the standard operation mode m ₁ , the road surface condition and the driving condition in which the slip ratio needs to be controlled most frequently, that is, the road condition and the driving condition that the driver is most likely to encounter. Is set. For example, the standard operating mode m ₁
The slip ratio control when driving in slippery corners,
The operation mode m ₂ is slip ratio control when traveling on a deep snowy road or a slippery slope, the operation mode m ₃ is slip ratio control when traveling on a slippery flat road such as a frozen road or a snowy road, and the operation mode m _n is uneven. A plurality of operation modes having different thresholds serving as control standards, such as slip ratio control during traveling on a rough road, are assigned according to the number of mode contacts of the mode selection switch 3.

The specific control operation by the control circuit 6 is as shown in FIG. The control of the slip ratio is started by turning on the ignition key (that is, engine start) (step 101), and regardless of the setting of the mode selection switch 3, first, the control by the standard operation mode m ₁ is started by the initial setting. Meanwhile (step 10
2) The mode selection by the mode selection switch 3 is judged (step 103), and when an operation mode other than the standard operation mode m ₁ is selected by the mode selection switch 3, the control operation is performed by the mode selection switch 3. Switch to the selected operation mode (steps 111 to 1)
14). Then, the slip ratio control for the operation mode selected by the mode selection switch 3 is ended by turning off the ignition key (step 12).
1). When the operation mode is switched by the mode selection switch 3 during the slip ratio control processing, the control processing is switched to the newly selected operation mode.

For example, in the case of the above-described embodiment, the slip ratio control in the standard operation mode m ₁ is started by the initial setting, and the ASR actuator 2 is controlled so that the slip ratio falls within a predetermined range when the vehicle runs on a slippery corner. However, if the traveling road is traveling on a slippery flat road such as an icy road or a snow-covered road, the driver switches the mode selection switch 3 to the contact M ₃ to perform more suitable slip ratio control. Will be done. Further, when the driver runs over a slippery flat road such as a frozen road or a snow-covered road and newly enters a bad road, the driver further sets the mode selection switch 3 to the contact M.
_By switching to _n , slip ratio control more suitable for rough roads will be implemented.

As described above, in the traction control system 1 according to the embodiment, each operation mode selectable by the mode selection switch 3 corresponds to various road surface conditions and driving conditions having different ideal slip ratios. However, by changing the operation mode in accordance with changes in conditions such as road conditions and driving conditions, it is possible to flexibly respond to changes in conditions. Therefore, the situation in which the system can be effectively operated is expanded, and in various situations where slip is likely to occur, the slip ratio of the wheels is maintained in an ideal state to improve the start / acceleration. It is possible to improve turning stability and maneuverability.

Further, since a plurality of operation modes are realized by changing the threshold value serving as a reference for controlling the ASR actuator 2, it is easy to equip a large number of operation modes having different slip ratio ranges to be controlled. become,
Simplification of the configuration of the ASR control unit 4,
Manufacturing costs can be reduced.

Further, the mode selection switches 3 and A
In the SR control unit 4, as the operation mode of the ASR actuator 2, a standard operation mode m ₁ and a plurality of operation modes m _{2 to mn} in which a threshold serving as a control reference is different from the standard operation mode m ₁ are prepared. Since the standard operation mode m ₁ which is frequently used is initialized immediately after the engine of the vehicle is started, the number of times the driver operates the mode selection switch 3 is reduced to reduce the burden on the driver. It is possible to enjoy the effect of controlling the slip ratio.

Although the threshold value is set to the speed detected from the behavior of the non-driving wheels in the above-described embodiment, the acceleration of the non-driving wheels can be used instead of the speed. The acceleration of the non-driving wheels shows the characteristic as shown by the curve f ₂ in FIG. 2. Even if such acceleration of the non-driving wheels is used as a threshold setting base, the slip ratio control by a plurality of operation modes is possible. .

[0028]

According to the traction control system of the present invention, if each operation mode selectable by the mode selection switch is made to correspond to the road surface condition or the driving condition in which the ideal slip ratio is different, the road surface condition can be improved. It is possible to flexibly respond to changes in the situation by switching the operation mode according to changes in the circumstances such as the driving situation. Therefore, the situation in which the system can be effectively operated is expanded, and in various situations where slip is likely to occur, the slip ratio of the wheels is maintained in an ideal state to improve the start / acceleration. It is possible to improve turning stability and maneuverability. Further, by adopting a configuration that realizes a plurality of operation modes by changing a threshold value that is a reference for controlling the ASR actuator, it becomes easy to equip a large number of operation modes having different slip ratio ranges to be controlled, It is possible to simplify the configuration of the ASR control unit and reduce the manufacturing cost. Furthermore, the mode selection switch and the ASR control unit are provided with a standard operation mode and one or more operation modes in which a threshold serving as a control reference is different from the standard operation mode, as the operation mode of the ASR actuator, If the standard operation mode is initially set immediately after the engine of the vehicle is started, the road surface condition and the driving condition, which are relatively easy to encounter, are made to correspond to the standard operation mode, so that the mode selection switch of the driver can be changed. It is possible to reduce the number of operations and reduce the burden on the driver, and to enjoy the effect of controlling the slip ratio.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a traction control system according to the present invention.

FIG. 2 is an explanatory diagram showing a method of setting each operation mode in the traction control system according to the embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the traction control system of the embodiment of the present invention.

[Explanation of symbols]

1 Traction control system 2 ASR actuator 3 Mode selection switch 4 ASR control unit 5 I / O section 6 Control circuit m _{1 to mn} Operation mode

Claims (4)

[Claims] 1. An AS for controlling slip of a drive wheel
R actuator, a mode selection switch for selecting an operation mode for controlling the slip of the driving wheel, and an ASR control for controlling the operation of the ASR actuator and switching the operation characteristic of the ASR actuator according to the setting of the mode selection switch. A traction control system characterized by comprising a unit and changing the characteristics of drive wheel slip control by selecting an operation mode by the mode selection switch. 2. The traction control system according to claim 1, wherein the ASR control unit realizes a plurality of operation modes by changing a threshold value serving as a reference for controlling the ASR actuator. 3. The traction control system according to claim 2, wherein the threshold value is a speed or an acceleration detected from the behavior of the non-driving wheels. 4. The mode selection switch and the ASR control unit include, as an operation mode of the ASR actuator, a standard operation mode and one or more operation modes in which a threshold serving as a control reference is different from the standard operation mode. The traction control system according to claim 2 or 3, wherein the standard operation mode is prepared and is initialized immediately after the engine of the vehicle is started.