JP2004116401A - Traction controlling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traction control device with good response. <P>SOLUTION: An ECU computes a target slip quantity according to revolution speed of a driven wheel when excessive slip of a drive wheel is detected. The ECU computes target revolution speed of the drive wheel to make slip quantity of the drive wheel the target slip quantity in step 102. The ECU computes clutch torque change quantity required for getting target revolution speed of the drive wheel in step 103. The clutch torque is determined by pressing load of a clutch disk and clutch wheel, the pressing load is determined by stroke of a rod pressing the clutch disk to a fly wheel side. The ECU computes stroke of the clutch required for getting desired clutch torque and controls the rod to maintain the stroke in step 104. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a traction control device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a system that performs traction control for preventing a slip of a drive wheel at the time of sudden start or the like. As such a traction control system, for example, a slip is detected based on a difference in rotation speed between a drive wheel and a driven wheel, and when a slip is detected, an electronic throttle is closed to reduce engine torque and suppress slip. (See, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-7-139376 (page 5)
[0004]
[Problems to be solved by the invention]
However, in the method of reducing the engine torque by closing the electronic throttle, the engine torque cannot be reduced quickly due to the responsiveness of the electronic throttle and the effect of the engine inertia. Therefore, there is a problem that the responsiveness of the actual slip suppression effect to the request for slip suppression is poor, and traction control cannot be suitably performed.
[0005]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a responsive traction control device.
[0006]
[Means for Solving the Problems]
The first aspect of the present invention provides a flywheel that rotates integrally with an output shaft of an engine, a clutch disk that is disposed to face the flywheel and is connected to an input shaft of a transmission of a vehicle, and the flywheel; Control means for controlling the pressure contact load with the clutch disk, and calculating means for calculating the slip amount of the wheel, the control means, so that the slip amount calculated by the calculating means becomes a target slip amount, The torque transmitted to the input shaft of the transmission via the clutch disk is controlled.
[0007]
The invention according to claim 2 is the invention according to claim 1, further comprising a clutch actuator that controls the drive of the clutch disk so that the clutch disk is pressed against the flywheel, wherein the clutch actuator is The crimping load is controlled by the stroke of a rod included in the clutch actuator.
[0008]
According to a third aspect of the present invention, in the first or second aspect of the invention, the calculating means determines a slip amount of the driving wheel based on a difference between a rotation speed of a driving wheel and a rotation speed of a driven wheel of the vehicle. And the target slip amount is calculated based on the rotation speed of the driven wheel.
[0009]
(Action)
According to the first or second aspect of the present invention, the torque transmitted to the input shaft of the transmission via the clutch disk is controlled by controlling the pressure load between the flywheel and the clutch disk by the control means. Therefore, the control of the torque performed when controlling the slip amount to the target slip amount is directly performed by controlling the pressure applied between the flywheel and the clutch disk. Therefore, a traction control device with extremely excellent responsiveness is realized.
[0010]
According to the third aspect of the invention, the slip amount of the drive wheel is calculated based on the difference between the rotation speed of the drive wheel and the rotation speed of the driven wheel, and the target slip amount is calculated based on the rotation speed of the driven wheel. You. Therefore, the calculation load is reduced as compared with the case where the slip amount and the target slip amount of the drive wheels are obtained using a map or the like.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a schematic configuration diagram of a vehicle control system to which the present invention is applied. In the present embodiment, a case will be described in which the vehicle is a vehicle (specifically, a front-wheel drive vehicle) in which the driving force of the vehicle is applied only to the front wheels of the vehicle.
[0012]
In the vehicle control system, an automatic clutch 20 is mounted on a flywheel 10a that rotates integrally with an output shaft (crankshaft) of an engine 10, which is an internal combustion engine, and an automatic transmission 30 is connected via the automatic clutch 20. I have.
[0013]
The engine 10 includes a throttle valve 11 for adjusting an intake air amount, a throttle sensor 12 for detecting an opening of the throttle valve 11 (throttle opening), and a throttle actuator 13 for opening and closing the throttle valve 11. It is arranged. The accelerator pedal 14 which is depressed by the vehicle driver is provided with an accelerator sensor 15 for detecting the operation amount (accelerator opening) of the accelerator pedal 14. The throttle actuator 13 is driven based on the accelerator opening detected by the accelerator sensor 15, and an engine output corresponding to the accelerator operation by the vehicle driver is obtained. Further, the engine 10 is provided with an engine speed sensor 16 for detecting the engine speed Ne.
[0014]
The automatic clutch 20 includes a mechanical (dry single-plate) friction clutch 21, a clutch lever 22, and a clutch actuator 23 for operating rotation transmission by the friction clutch 21 via the clutch lever 22.
[0015]
The friction clutch 21 includes a clutch disk 21a that rotates integrally with the input shaft 31 of the automatic transmission 30. The friction clutch 21 rotates between the flywheel 10a and the clutch disk 21a (between the output shaft of the engine 10 and the input shaft 31 of the automatic transmission 30) by changing the pressure applied by the clutch disk 21a to the flywheel 10a. Vary transmission.
[0016]
The clutch actuator 23 includes a DC electric motor 24 as a drive source, and the drive of the motor 24 causes the rod 25 to move forward or backward (advance / retreat) to move the clutch lever 22. As a result, the release bearing 27 is pushed through the clutch lever 22 and the diaphragm spring 28 elastically contacting the release bearing 27 is deformed to generate a pressure load on the pressure plate 29. By moving the clutch lever 22 via the rod 25, the clutch actuator 23 changes the pressure applied by the clutch disc 21a to the flywheel 10a via the pressure plate 29 in the above-described manner, and transmits the rotation by the friction clutch 21. Operate.
[0017]
Specifically, when the rod 25 is moved forward (advanced) and the clutch lever 22 is pushed to the right in FIG. 1 by the rod 25, the pressure applied by the clutch disc 21a to the flywheel 10a is reduced. ing. Conversely, when the rod 25 moves backward (retreats) and the clutch lever 22 is returned, the pressure applied to the clutch disk 21a against the flywheel 10a is increased.
[0018]
Here, the relationship between the movement position (stroke) of the rod 25 and the rotation transmission by the friction clutch 21 will be described. When the rod 25 is moved (advanced) forward, finally, there is substantially no pressure applied to the clutch disk 21a against the flywheel 10a. At this time, the flywheel 10a and the clutch disc 21a are separated, and the rotation transmission between the flywheel 10a and the clutch disc 21a is stopped. The stroke of the rod 25 at this time is called a standby position.
[0019]
When the rod 25 is moved backward (retracted) from the standby position, the pressure applied to the clutch disk 21a against the flywheel 10a increases in accordance with the amount of movement. At this time, rotation is transmitted between the flywheel 10a and the clutch disc 21a with a rotational speed difference (clutch slip amount) corresponding to the pressing load. In particular, when the rotational speed difference (hereinafter, referred to as “clutch slip amount”) becomes substantially zero due to an increase in the pressure applied by the movement (retreat) of the rod 25, the flywheel 10a and the clutch disk 21a rotate synchronously. . Therefore, the clutch slip amount is controlled by controlling the movement amount of the rod 25 by the clutch actuator 23 from the standby position to the movement position at the time of synchronization.
[0020]
When the rod 25 is further moved backward (retracted) from the movement position at the time of the synchronization, the pressure load of the clutch disk 21a against the flywheel 10a further increases in accordance with the amount of movement. Then, when the rod 25 is separated from the clutch lever 22, the flywheel 10a and the clutch disk 21a rotate synchronously with an excessive crimping load applied. The stroke of the rod 25 at this time is called a complete engagement position. Accordingly, by holding the rod 25 in the fully engaged position by the clutch actuator 23, the friction clutch 21 is completely engaged, and the flywheel 10a and the clutch disk 21a are synchronously controlled.
[0021]
Hereinafter, the torque transmitted to the input shaft 31 via the clutch disc 21a in connection with the above-described rotation transmission is represented by clutch torque Tc. This clutch torque Tc is used to drive the vehicle (drive wheel 34).
[0022]
The automatic clutch 20 is provided with a stroke sensor 26 for detecting the movement position (stroke) of the rod 25 of the actuator 23. The transmission of rotation by the friction clutch 21 is performed based on the stroke St detected by the stroke sensor 26. The state is represented.
[0023]
The automatic transmission 30 has an input shaft 31 and an output shaft 32. The input shaft 31 of the automatic transmission 30 is connected to the clutch disc 21 a of the friction clutch 21 so as to transmit power, and the output shaft 32 is connected to the axle of driving wheels 34 so as to transmit power. The drive wheel 34 is provided with a drive wheel sensor 37 for detecting the number of rotations of the drive wheel 34.
[0024]
On the other hand, the driven wheel 35 (the wheel on the vehicle rear side in the present embodiment) is provided with a driven wheel sensor 38 for detecting the rotation speed of the driven wheel 35.
The automatic transmission 30 is provided with a shift actuator 41 for switching the gear position, and changes the gear connection state.
[0025]
The vehicle control system in FIG. 1 includes an electronic control unit (ECU) 50 as a control unit for performing various controls and an arithmetic unit. The ECU 50 mainly includes a well-known microcomputer (CPU), and includes a ROM storing various programs and maps, a RAM capable of reading and writing various data, an EEPROM capable of holding data without a backup power supply, and the like. Have. The ECU 50 includes various sensors such as the throttle sensor 12, the accelerator sensor 15, the engine speed sensor 16, the stroke sensor 26, the drive wheel sensor 37, the driven wheel sensor 38, the throttle actuator 13, the clutch actuator 23, Actuator 41 is connected. The ECU 50 fetches detection signals from various sensors, and thereby, based on the vehicle operation state (throttle opening, accelerator opening, engine speed, rotation transmission state by the friction clutch 21, vehicle speed, drive wheel speed, driven wheel speed, etc.). Is detected. Then, the ECU 50 drives the throttle actuator 13, the clutch actuator 23, and the shift actuator 41 based on the vehicle driving state.
[0026]
Specifically, the ECU 50 obtains the operation amount (accelerator opening) of the accelerator pedal 14 based on the detection value of the accelerator sensor 15, and drives the throttle actuator 13 based on the accelerator opening. Thus, the amount of intake air to the engine 10 is adjusted, and an engine output corresponding to the accelerator operation of the vehicle driver can be obtained.
[0027]
Further, the ECU 50 drives the clutch actuator 23 to adjust the rotation transmission by the clutch 21. Thus, the clutch torque Tc by the friction clutch 21 according to the vehicle driving state is automatically controlled.
[0028]
Further, the shift actuator 41 is driven to switch the gear train (gear stage) to which power can be transmitted in the automatic transmission 30. Thereby, the gear position in the automatic transmission 30 according to the vehicle driving state is automatically controlled.
[0029]
Here, the relationship between the rotational speed of the drive wheel 34 and the clutch torque Tc and the relationship between the target stroke of the rod 25 (clutch target stroke) and the clutch torque Tc for controlling the clutch torque Tc will be described. The clutch target stroke is a stroke calculated and set to move the rod 25 to a required position, and the ECU 50 determines that the stroke St detected by the stroke sensor 26 substantially matches the clutch target stroke. A drive signal is output to the actuator 23 for use.
[0030]
When it is necessary to control the clutch torque Tc, for example, when the drive wheels 34 excessively slip at the time of sudden start, the ECU 50 first calculates the target rotation speed of the drive wheels 34. The target rotation speed of the driving wheel 34 is determined by the rotation speed of the driven wheel 35, and is set so that an optimum slip amount is generated according to the rotation speed of the driven wheel 35.
[0031]
FIG. 2 is a graph showing a relationship between the rotation speed of the driven wheel 35 and the rotation speed of the drive wheel 34. A broken line L1 in the drawing indicates a state where the rotation speed of the driven wheel 35 is equal to the rotation speed of the driving wheel 34, and a solid line L2 indicates a target rotation speed of the driving wheel 34 when an optimum slip amount is generated in the driving wheel 34. Is represented. That is, the difference between the solid line L2 and the broken line L1 represents the optimum slip amount (target slip amount) according to the rotation speed of the driven wheel 35.
[0032]
The target rotation speed of the drive wheel 34 increases in proportion to the rotation speed of the driven wheel 35 as the rotation speed of the driven wheel 35 increases, and the target rotation speed of the drive wheel 34 and the rotation speed of the driven wheel 35 increase as the rotation speed of the driven wheel 35 increases. The difference with the numbers is also increasing. That is, the target slip amount increases as the rotation speed of the driven wheel 35 increases.
[0033]
The target slip amount is set so as to increase in proportion to the rotation speed of the driven wheel 35, and is multiplied by a predetermined target slip ratio r (r is a number greater than 1) by multiplying the rotation speed of the drive wheel 34 by a predetermined amount. It is also possible to calculate the target rotation speed of 34.
[0034]
The ECU 50 controls the clutch torque Tc so that the actual rotation speed of the drive wheel 34 approaches the target rotation speed of the drive wheel 34 calculated in this way.
FIG. 3 is a graph showing a relationship between the number of rotations of the drive wheel 34 and the clutch torque Tc required to obtain a required number of rotations of the drive wheel 34. The horizontal axis in the drawing represents the rotation speed of the drive wheel 34, and the vertical axis in the drawing represents the clutch torque Tc. As shown in the figure, the graph draws a straight line rising to the right. That is, in order to increase the number of rotations of the drive wheel 34, a larger clutch torque Tc is required accordingly.
[0035]
FIG. 4 is a graph showing the relationship between the clutch torque Tc and the stroke St of the rod 25. The horizontal axis of the drawing represents the clutch torque Tc, and the vertical axis of the drawing represents the stroke St of the rod 25. The stroke St represents the side on which the rod 25 moves backward (retreats) from the standby position to the front side. Therefore, as the stroke St increases, the pressure applied between the flywheel 10a and the clutch disc 21a increases.
[0036]
Note that, in the drawing, the range from the origin to the stroke “St0” where the clutch torque Tc does not change because the flywheel 10a does not contact the clutch disc 21a even if the rod 25 is moved backward (retreats). Further, the stroke “St0” indicates that the stroke St of the rod 25 is the standby position, and the position where the stroke St becomes “St3” corresponds to the above-described full engagement position. The clutch disc 21a has a preset upper limit clutch torque Tc that can be transmitted between the flywheel 10a and the clutch disc 21a. If the clutch disc 21a attempts to transmit a clutch torque Tc greater than that value, the clutch disc 21a 10a is caused to slip. When the slip occurs, no more clutch torque Tc can be transmitted to the drive wheels 34, and the upper limit is indicated by "Tc3" in the figure.
[0037]
Next, traction control in the present embodiment will be described based on the graphs of FIGS. 2 to 4 and the flowchart of FIG. This control is executed by a periodic interruption every predetermined time when the vehicle starts moving.
[0038]
When the process proceeds to this routine, the ECU 50 first reads the vehicle condition before clutch control, specifically, the stroke St of the rod 25, the clutch torque Tc, the rotation speed of the drive wheel 34, and the rotation speed of the driven wheel 35, The information is temporarily stored in a memory. In this embodiment, in this state, the stroke St of the rod 25 is “St2”, the value of the clutch torque Tc is “Tc2”, the rotational speed of the drive wheel 34 is “V2”, and the rotational speed of the driven wheel 35 is The description will be made assuming that “Vr1”.
[0039]
When the process proceeds to this routine, first in step 101, the ECU 50 determines the slip of the drive wheel 34 from the difference between the rotation speed "V2" of the drive wheel 34 (front wheel) and the rotation speed "Vr1" of the driven wheel 35 (rear wheel). Calculate the quantity. Then, the ECU 50 determines whether or not the difference between the rotation speed “V2” of the drive wheel 34 and the rotation speed “Vr1” of the driven wheel 35 is larger than a preset slip determination threshold value.
[0040]
If the slip amount of the drive wheel 34 is larger than the slip determination threshold, the ECU 50 determines that excessive slip has occurred in the drive wheel 34, and shifts the processing to step 102.
[0041]
In step 102, the ECU 50 calculates the target rotation speed “V1” of the drive wheel 34 in the above-described manner based on the rotation speed “Vr1” of the driven wheel 35 detected by the drive wheel sensor 37.
[0042]
Next, in step 103, the ECU 50 calculates a difference “ΔV” between the target rotation speed “V1” of the drive wheel 34 and the actual rotation speed “V2”. Then, the ECU 50 calculates a change amount “ΔTc” of the clutch torque Tc required to change the rotation speed of the drive wheel 34 by “ΔV”.
[0043]
After calculating the amount of change “ΔTc” of the clutch torque Tc, the ECU 50 shifts the processing to step 104 and controls the stroke of the rod 25. Specifically, as shown in FIG. 4, a change amount “ΔSt” of the stroke St necessary to change the clutch torque Tc from “Tc2” to “Tc1” by “ΔTc” is calculated, and the current stroke is calculated. This is reflected in a certain “St2”. Since the clutch torque Tc can be changed from the standby position to the fully engaged position as described above, the control of the clutch torque Tc is performed within a range from “0” to “Tc3”.
[0044]
When the new stroke “St1” is obtained by reflecting the change amount “ΔSt” of the stroke St to the current stroke “St2”, the ECU 50 sets the clutch St such that the stroke St detected by the sensor 26 substantially matches this “St1”. A drive signal is output to the actuator 23, and the subsequent processing is temporarily terminated.
[0045]
On the other hand, if the difference between the rotation speed “V2” of the driving wheel 34 and the rotation speed “Vr1” of the driven wheel 35 is smaller than the slip determination threshold value in step 101, the ECU 50 determines the clutch torque Tc due to the occurrence of slip. It is determined that control is not necessary, and the process proceeds to step 105.
[0046]
In step 105, the ECU 50 controls the clutch in a state where no slip occurs in the drive wheels 34 of the vehicle, that is, in a so-called normal running state of the vehicle, specifically, controls the connection and disconnection of the clutch due to gear shifting. When such normal clutch control is performed, the ECU 50 once ends the subsequent processing.
[0047]
As described in detail above, according to the present embodiment, the following effects can be obtained.
(1) When the ECU 50 detects the slip of the drive wheel 34 equal to or more than the slip determination threshold value, the clutch St is controlled by changing the stroke St of the rod 25. Therefore, the control of the drive wheel 34 to the target slip amount can be directly performed by the clutch torque Tc, and the throttle valve 11 can be controlled as compared with the case where the drive torque of the engine 10 is changed by opening and closing the throttle valve 11. Of the engine 10 and inertia of the engine 10. Therefore, the clutch torque Tc can be quickly controlled, and the rotational speed of the drive wheel 34 can be brought close to the target rotational speed with good responsiveness.
[0048]
(2) Upon detecting the rotation speed of the driven wheel 35, the ECU 50 can calculate the target rotation speed of the drive wheel 34 according to the rotation speed of the driven wheel 35 by multiplying the rotation speed by the target slip ratio r. . Therefore, it is possible to quickly calculate the target rotation speed of the drive wheel 34 according to the traveling state of the vehicle.
[0049]
Note that the embodiment of the present invention is not limited to the above-described embodiment, and may be modified as follows.
In the above embodiment, the change amount “ΔTc” of the clutch torque Tc is calculated from the difference “ΔV” between the target rotation speed “V1” of the drive wheel 34 and the actual rotation speed “V2”, and the “ΔTc” , The stroke “ΔSt” is calculated, and the stroke “St1” after the control is determined by reflecting the “ΔSt” on the stroke “St2” before the control. However, the control need not be performed based on each detection value before the control. For example, the value “Tc1” of the clutch torque Tc required to output the target rotation speed “V1” of the drive wheel 34 is determined in FIG. The stroke “St1” necessary for outputting the value “Tc1” may be directly obtained from the graph of FIG. 4.
[0050]
In the above-described embodiment, the clutch torque Tc is controlled by changing the stroke St of the rod 25 to change the pressure load between the flywheel 10a and the clutch disc 21a. However, the stroke St of the rod 25 may be changed to reduce the pressure applied to the flywheel 10a and the clutch disc 21a to reduce the clutch torque Tc, and at the same time, drive the throttle actuator 13 to suppress the engine output. Good. By suppressing the output of the engine at the same time as reducing the clutch torque Tc in this way, it is possible to suppress the engine blow-up caused by a decrease in the load on the engine when the clutch is stroked in the disengagement direction. .
[0051]
In the above embodiment, the clutch St is controlled by changing the stroke St of the rod 25 to change the pressure applied between the flywheel 10a and the clutch disk 21a. However, the output of the engine may be controlled while controlling the clutch torque Tc. By configuring the traction control device in this way, a responsive traction control device with higher responsiveness can be provided.
[0052]
In the above embodiment, the rotation speed of the driving wheel 34 is measured by the driving wheel sensor 37 that detects the rotation speed of the driving wheel 34. However, it is sufficient that the rotation speed of the drive wheel can be correctly detected. For example, a sensor for detecting the rotation speed of the output shaft 32 of the automatic transmission 30 may be provided, and the rotation speed of the drive wheel may be detected by the sensor.
[0053]
In the above embodiment, the traction control device is applied to the front wheel drive vehicle in which the driving force of the wheels is applied only to the wheels on the front side of the vehicle, but the driving force of the wheels is applied only to the wheels on the rear side of the vehicle. It may be applied to a rear wheel drive vehicle.
[0054]
In the above embodiment, the ECU 50 performs the traction control by the proportional control that changes the stroke St of the rod 25 in proportion to the difference between the target rotation speed “V1” of the drive wheel 34 and the actual rotation speed “V2”. Was. However, in addition to the proportional control, the deviation between the target rotational speed "V1" of the drive wheel 34 and the actual rotational speed is accumulated over time, and when the magnitude becomes a predetermined value, the change amount of the stroke St of the rod 25 becomes Traction control may be performed by PI control to which the reflected integration operation is added.
[0055]
Further, in order to increase the response speed of the traction control, the traction control may be performed by PID control to which a differential operation is further added.
Next, technical ideas that can be grasped from the above embodiments are described below together with their effects.
[0056]
(A) The traction control device according to any one of claims 1 to 3, wherein the output of the engine is suppressed immediately after the pressure load between the flywheel and the clutch disk is reduced. According to this configuration, the load on the output shaft of the engine decreases when the pressure applied between the flywheel and the clutch disc is reduced, but immediately after that, the engine output is suppressed to suppress the engine from rising. Can be.
[0057]
(B) The traction control device according to any one of claims 1 to 3, wherein a crimping load between the flywheel and the clutch disc is controlled and an output of the engine is controlled. According to this configuration, the output of the engine is set to be low at the same time when the crimp load between the flywheel and the clutch disc is reduced, and the engine output is set to be high at the same time when the crimp load between the flywheel and the clutch disc is increased. As a result, a traction control device with better responsiveness is obtained.
[0058]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a responsive traction control device.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a vehicle control system.
FIG. 2 is a diagram showing a correlation between the rotation speed of a driven wheel and the rotation speed of a driving wheel.
FIG. 3 is a diagram showing a correlation between the rotational speed of drive wheels and clutch torque.
FIG. 4 is a diagram showing a correlation between a clutch torque and a stroke.
FIG. 5 is a flowchart of traction control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Engine, 10a ... Flywheel, 21a ... Clutch disk, 23 ... Clutch actuator, 25 ... Rod, 30 ... Automatic transmission, 31 ... Input shaft, 34 ... Drive wheel, 35 ... Driven wheel, 37 ... Drive wheel sensor , 38: driven wheel sensor, 50: ECU as control means and calculation means.

Claims (3)

A flywheel that rotates integrally with the output shaft of the engine,
A clutch disk that is arranged to face the flywheel and is connected to an input shaft of a transmission of a vehicle;
Control means for controlling a compression load of the flywheel and the clutch disc,
Calculating means for calculating the wheel slip amount,
The traction control, wherein the control means controls a torque transmitted to an input shaft of the transmission via the clutch disk such that the slip amount calculated by the calculation means becomes a target slip amount. apparatus. A clutch actuator for driving and controlling the clutch disc so that the clutch disc is pressed against the flywheel,
The traction control device according to claim 1, wherein the clutch actuator controls the pressure load by a stroke of a rod included in the clutch actuator. The calculating means calculates a slip amount of the driving wheel based on a difference between a rotation speed of a driving wheel of the vehicle and a rotation speed of a driven wheel, and the target slip amount is calculated based on a rotation speed of the driven wheel. The traction control device according to claim 1 or 2, wherein:

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