JP2000027675A - Traction control method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the combustion during traction control so as to carry out precise control by previously changing over stratified combustion into homogenous combustion or by successively maintaining homogeneous combustion in such a case that occurrence of a slip is expected. SOLUTION: A traction control device is composed of a slip value computing means 22 for computing a slip value from outputs from vehicle speed sensors 3 to 6, a torque-down demand value computing means 23 for computing a torque-down demand value for restraining slipping, from the slip value and a generated torque value, a fuel-cut carrying part 27a for cutting off fuel in accordance with the torque-down demand value and a stratified combustion inhibiting and determining part 34 for inhibiting stratified combustion of an engine either when it is detected that a frequency with which the slip value exceeds a predetermined value within a first or a second predetermined time after the time when the slip value converges to a value higher or lower than a predetermined value, or when it is detected that the hysteresis of an engine cooling water does not satisfy a predetermined condition.

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 and a traction control method, and more particularly, to accurately performing torque reduction control of an engine having a stratified combustion mode and a homogeneous combustion mode and stabilizing combustion during traction control. Traction control method and apparatus.

[0002]

2. Description of the Related Art When a driving force greater than a frictional force between a driving wheel and a road surface is applied at the time of starting or sudden acceleration of the vehicle, the driving wheel slips and impairs the drivability and steering stability of the vehicle. There is. In order to cope with this, a traction control device that suppresses the slip by reducing the output of the engine irrespective of the driver's throttle operation until the slip of the drive wheel is eliminated is known.

In this traction control device,
An engine torque for suppressing the slip of the drive wheel is obtained based on a wheel speed difference between the drive wheel and the non-drive wheel, and a throttle valve opening corresponding to the engine torque is obtained from the engine torque to control the throttle valve. . In addition, since only the throttle valve control causes a response delay until the intake air amount is reduced, a fuel cut for reducing the number of cylinders (operating cylinders) to be supplied with fuel may be used together.

[0004] In recent years, social awareness of the environment has increased, and market demands such as effective use of buried fuel and suppression of CO2 emissions for preventing global warming have been increasing. Further improvement in fuel economy is needed.

[0005] Improvements in fuel efficiency in gasoline engines are:
It is realized by operating in a lean burn region where the air-fuel ratio is larger than the stoichiometric air-fuel ratio (A / F = 14.7). However, there is also a demand for achieving both low fuel consumption and power performance.

[0006] For this reason, some engines use both modes selectively, such as operating in a stratified combustion mode with good fuel efficiency at low load and operating in a homogeneous combustion mode with high output at high load.

[0007]

However, when a traction control is performed in a vehicle equipped with an engine having a stratified combustion mode and a homogeneous combustion mode, there are the following problems.

That is, when traction control is performed by detecting slippage of the driving wheels during stratified charge combustion, engine combustion becomes unstable, torque control accuracy may deteriorate, and smooth engine rotation may not be obtained. Was.

In order to avoid this, there is an apparatus that performs traction control by switching from stratified combustion to homogeneous combustion when a slip of a drive wheel is detected. However, when switching from stratified combustion to homogeneous combustion, or vice versa, homogenous combustion is performed. The air-fuel ratio is gradually changed to prevent a torque step at the time of switching from combustion to stratified combustion.Thus, during switching, combustion remains unstable, and torque control accuracy also deteriorates. There is a problem that the traction control performance is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to switch from stratified combustion to homogeneous combustion in advance or to switch to homogeneous combustion when a situation in which slip is likely to occur is predicted. A traction control method and apparatus capable of stabilizing combustion during traction control, performing high-precision torque control, and, when slip is not predicted, enabling stratified combustion to achieve low fuel consumption. To provide.

[0011]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, a slip amount of a drive wheel is detected from a rotation speed of each wheel of a vehicle equipped with an engine capable of homogeneous combustion and stratified combustion, and the slip amount and a torque amount generated by the engine are determined. A traction control method of calculating a torque reduction amount for suppressing a slip based on the torque reduction amount and performing a fuel cut for each cylinder of the engine based on the torque reduction amount, wherein the slip amount is equal to or more than a predetermined value. The gist is that the stratified combustion of the engine is not performed.

According to a second aspect of the present invention, to solve the above problem, a slip amount of a drive wheel is detected from a rotational speed of each wheel of a vehicle equipped with an engine capable of homogeneous combustion and stratified combustion. A traction control method of calculating a torque reduction amount for suppressing slip based on the amount and a torque amount generated by the engine, and performing a fuel cut for each cylinder of the engine based on the torque reduction amount, When the slip amount has converged to a predetermined value or less within a first predetermined time,
The gist is that the stratified combustion of the engine is not performed.

According to a third aspect of the present invention, to solve the above problem, a slip amount of a drive wheel is detected from a rotational speed of each wheel of a vehicle equipped with an engine capable of homogeneous combustion and stratified combustion, and the slip amount is detected. A traction control method of calculating a torque reduction amount for suppressing slip based on the amount and a torque amount generated by the engine, and performing a fuel cut for each cylinder of the engine based on the torque reduction amount, The gist is that the stratified combustion of the engine is not performed until a third predetermined time elapses from the time when the number of times the slip amount exceeds the predetermined value within the second predetermined time reaches the predetermined number.

According to a fourth aspect of the present invention, there is provided a traction control method according to any one of the first to third aspects, wherein the history of the cooling water temperature does not satisfy a predetermined condition. In this case, the gist is that the stratified combustion of the engine is not performed.

According to a fifth aspect of the present invention, there is provided a traction control method according to any one of the first to third aspects, wherein the predetermined value of the slip amount is determined based on a value of a driven wheel and a driving wheel. And that the speed difference is 20 to 30 km / h.

According to a sixth aspect of the present invention, there is provided a traction control method according to the third aspect, wherein the first predetermined time is shorter than the second predetermined time. I do.

According to a seventh aspect of the present invention, there is provided an engine capable of performing homogeneous combustion and stratified combustion, a wheel speed detecting means for detecting a rotational speed of each wheel of a vehicle, and the wheel speed detecting means. Means for calculating the slip amount of the drive wheel based on the speed of each wheel detected by the means, and a slip based on the slip amount calculated by the slip amount calculation means and the torque generated by the engine. A torque-down amount calculating means for calculating a torque-down amount for suppressing the fuel-cut amount, a fuel-cut control means for performing a fuel cut for each cylinder of the engine based on the torque-down amount calculated by the torque-down amount calculating means, A water temperature sensor for detecting a cooling water temperature of the engine, wherein the slip amount is equal to or more than a predetermined value, or the slip amount is Within a first predetermined time from the point in time when the value converges to the predetermined value or less, or the number of times that the slip amount exceeds the predetermined value within a second predetermined time is equal to or more than a predetermined number, or the cooling water temperature And a combustion mode control means for controlling so that stratified combustion of the engine is not performed when any one of the following conditions is not satisfied. It is.

[0018]

According to the first aspect of the present invention, the slip amount of the drive wheel is detected from the rotation speed of each wheel,
When it is detected that the slip amount is equal to or larger than a predetermined value, it is determined that μ on the road surface is extremely low, and control is performed so that stratified combustion is not performed. As a result, homogeneous combustion can be performed at the time of traction control, and highly accurate torque control can be performed, and instability of combustion can be avoided.

According to the second aspect of the present invention, if the slip amount is equal to or more than the predetermined value again within the first predetermined time from the time when the slip amount converges to the predetermined value or less, As expected, stratified combustion is not performed, and homogeneous combustion is continued. Thereby, for example, when traveling on a road in an urban area having a large number of intersections, even if there is a repeated start and stop, the homogeneous combustion state is continued, so that the traction control becomes homogeneous combustion and high-precision torque control is achieved. And combustion can be prevented from becoming unstable.

According to the present invention, when the number of times the slip amount exceeds the predetermined value within the second predetermined time reaches the predetermined number, it is determined that the low μ road is continued. Until the third predetermined time elapses from this point, the stratified charge combustion is not performed, and the homogeneous charge combustion is continued. As a result, homogeneous combustion can be performed at the time of traction control, and highly accurate torque control can be performed, and instability of combustion can be avoided.

Further, according to the present invention, when the history of the cooling water temperature does not satisfy the predetermined condition, for example, when the predetermined temperature or more does not continue for a predetermined time or more, the warm-up is sufficiently performed. By determining that it is not the case, and performing the homogeneous combustion without performing the stratified combustion, the combustion can be stabilized.

According to the fifth aspect of the present invention, the predetermined value of the slip amount is such that the speed difference between the driven wheel and the drive wheel is 20 to 30 km / h, so that the μ of the road surface is extremely low. By performing homogeneous combustion without performing stratified combustion when the vehicle is traveling, if traction control is activated, high-precision torque control can be performed in the state of homogeneous combustion, and unstable combustion can be achieved. Can be avoided.

According to the sixth aspect of the present invention, the stratified charge combustion is not performed for the first predetermined time from the time when the slip amount converges to the predetermined value or less, and the homogeneous combustion is continued, so that the intersection is maintained. Even when the vehicle starts and stops repeatedly and the traction control is frequently activated when passing through an urban area with high traffic, it is possible to perform highly accurate torque control in a homogeneous combustion state, Stabilization can be avoided. Further, when a slip amount exceeding a predetermined value is detected a predetermined number of times or more within a second predetermined time longer than the first predetermined time, it is determined that the low μ road surface condition is to be continued and the homogeneous combustion is performed without performing the stratified combustion. Thereby, if the traction control is activated, it is possible to perform highly accurate torque control in a state of homogeneous combustion, and to avoid unstable combustion.

Further, according to the present invention, the slip amount of the drive wheel is calculated from the rotational speed of the wheel detected by the wheel speed detecting means, and the slip amount is not less than a predetermined value, or The slip amount exceeds a predetermined value within a second predetermined time from the time when the amount converges to a predetermined value or less, or the number of times the slip amount exceeds a predetermined value within a second predetermined time is equal to or more than a predetermined number, If the history does not satisfy the predetermined condition, the combustion mode control means controls so that stratified combustion of the engine is not performed. Accordingly, it is possible to provide a traction control device capable of performing high-accuracy torque control by performing homogeneous combustion at the time of traction control and avoiding unstable combustion.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a system configuration of a first embodiment of a traction control device according to the present invention. In this embodiment, an example in which the present invention is applied to a rear-wheel drive vehicle will be described. However, in the case of applying to a front-wheel drive vehicle, only the drive wheels are replaced, and there is no essential change.

As shown in FIG. 1, a traction control device 1 includes an engine body 2 capable of performing homogeneous combustion and stratified combustion, a front right wheel speed sensor 3, a front left wheel speed sensor 4, a rear right wheel speed sensor 5, and a rear right wheel speed sensor. Left wheel speed sensor 6, slip amount calculating means for calculating the slip amount of the drive wheels based on the wheel speed signals detected by wheel speed sensors 3 to 6, and torque based on the slip amount and the torque generated by the engine. A traction control control unit (hereinafter abbreviated as traction control C / U) 7 as a torque down amount calculation means for calculating a down amount;
An engine control unit 8 as a fuel cut control means for performing a fuel cut for each cylinder of the engine based on the torque reduction amount calculated by the traction control C / U 7 and a combustion mode control means for the engine.
(Hereinafter abbreviated as engine C / U), an engine coolant temperature sensor 9 for detecting the temperature of the engine coolant, an air flow meter 10 for measuring the intake air amount, a throttle 11, and a throttle actuator 1 for controlling the opening of the throttle 11.
And 2.

FIG. 2 is a control block diagram of the traction control device 1 of the present embodiment, and shows a detailed configuration of the traction control C / U 7 and the engine C / U 8.

In FIG. 2, a traction control C / U 7 forms a waveform of detection signals from wheel speed sensors 3 to 6 each comprising a hub rotor and a pickup provided on each wheel and converts the signal into a digital signal. Unit 20, for example, a vehicle speed which is an average value of the wheel speeds of the driven wheels, and a wheel speed comparison / calculation unit 21 for calculating a difference between the vehicle speed and the wheel speed of each drive wheel; Calculate and judge the slip amount from the conditions and wheel speed difference,
Output to the engine C / U 8, a slip amount calculation unit 22 that outputs to the next stage, a torque down calculation unit 23 that calculates a required torque down amount based on the slip amount, and outputs a torque down control signal to the engine C / U 8. A torque-down control signal output unit 24 is provided.

The engine C / U 8 includes a torque down amount determining section 30 for determining the torque down amount based on the torque down control signal, a torque down execution timer counting section 31 for measuring the elapsed time after the torque down execution, and a traction. Throttle opening detection unit 32 that shapes a signal from control throttle opening sensor 12a and converts it into a digital signal, engine water temperature detection unit 33 that converts a signal from engine water temperature sensor 9 into a digital signal, and stratified combustion prohibition determination unit 34. A post-warm-up timer counting section 35, a homogeneous / stratified combustion switching section 36, a fuel injection control section 37 including a fuel cut execution section 37a, a traction control throttle control section 38 for controlling the throttle actuator 12, for example, intake of the engine body 12 Stratified fuel installed in the system And a gas flow control unit 39 for controlling the swirl control valve (SCV) actuator 43 for forming Yokouzu sometimes into the cylinder.

Next, the operation of the traction control C / U 7 in the embodiment of the present invention will be described with reference to the flowchart shown in FIG. The main operation of the traction control C / U 7 is to calculate a slip amount based on the detection value of each wheel speed sensor, to notify the slip amount to the stratified combustion inhibition determination unit 34 of the engine C / U 8, The required amount of torque reduction is obtained from the amount, and is notified to the torque reduction amount determination unit 30 of the engine C / U 8. In FIG. 3, for example, the operation is expressed in a subroutine format called at regular intervals.

First, a front right wheel speed (VFR), a front left wheel speed (VFL), a rear right wheel speed (VRR), and a rear left wheel speed are transmitted from each of the wheel speed sensors 3 to 6 via a wheel speed detection unit 20. Import the wheel speed (VRL) data (step S
1).

Next, the vehicle speed VB =
(VFR + VFL) / 2 is calculated (step S2), and the vehicle acceleration GB = (. DELTA.VB) /. DELTA.t is calculated (step S2).
3). Here, ΔVB is, for example, the difference between the currently calculated vehicle speed and the previously calculated vehicle speed, and Δt is the difference between the current time and the previously calculated time, that is, the calculation cycle.

Next, the slip amount for each drive wheel is calculated. If the slip amount of the right drive wheel is SR and the slip amount of the left drive wheel is SL, SR = VRR-VB and SL = VRL-V
B is calculated (step S4). Next, the slip amounts of the left and right drive wheels are compared (step S5), and the one with the larger slip amount is output to the engine C / U8 as the slip amount S to be controlled (steps S6, S7).

Next, the slip amount S and the traction control operation start slip amount Sth are compared (step S8). If S does not exceed Sth, the subroutine processing is terminated and the process returns to the main routine, where S is set to Sth. If it exceeds, the required amount of torque reduction is calculated (step S
9) The requested torque down amount is output to the engine C / U 8 (step S10), and the subroutine processing is ended to return to the main routine.

In the calculation of the required torque reduction amount in step S9, the throttle opening or the basic fuel injection amount (Tp) is referred to with reference to a generated torque map as shown in FIG.
And the engine speed are used as parameters to determine the engine generated torque. This engine generated torque, gear ratio,
Output torque TO transmitted to drive wheels from tire diameter
Can be calculated. Then, the effective torque TE actually transmitted to the road surface and accelerating the vehicle body from the vehicle body acceleration GB obtained in step 3 and the vehicle body weight and the driving wheel load.
Can be calculated. And ((TO-TE) /
TO) × 100 is set as the required amount of torque reduction% and output from the traction control C / U7 to the engine C / U8.

FIG. 4 is a flow chart for explaining the operation mainly of the stratified combustion prohibition judging section 34 of the engine C / U 8. The stratified combustion is prohibited by judging various conditions, or the stratified combustion prohibition is canceled. This is the main operation of the present invention for controlling the above.

First, the traction control C / U7
Reference is made to the flag indicating that the TCS is operating (step S21). If the TCS is operating, stratified combustion is prohibited (step S31). TCS if not in operation
After the end, the time timer is read (step S22), and T
It is determined whether a predetermined time has elapsed since the CS operation was completed (step S23).

If the predetermined time has not elapsed, stratified combustion is prohibited (step S31). If the predetermined time has elapsed, the slip amount S sent from the traction control C / U 7 is read (step S24), and the throttle opening is read via the throttle opening detector 32 (step S25). By referring to such a slip occurrence frequency determination table, a large slip occurrence frequency determination value (times) corresponding to the throttle opening is obtained.

[0040]

[Table 1] Then, it is determined whether or not the number of occurrences of the slip within a predetermined time of, for example, two minutes is equal to or less than a determination value of the number of occurrences of the large number of slips (step S27). If the number of slip occurrences within the predetermined time is not less than or equal to the large slip occurrence number determination value, stratified charge combustion is prohibited (step S31). Here, the slip amount determined to be a large slip is determined to be a large slip if the generated torque obtained from FIG. 7 with reference to the low μ determination map of FIG. I do.

If the number of occurrences of the slip within the predetermined time is equal to or less than the judgment value of the number of occurrences of the large number of slips, the history of the engine water temperature is read (step S28), and it is determined whether or not the state where the temperature is higher than the predetermined temperature continues for a predetermined time. I do. This determination condition can be, for example, 60 degrees or more and 5 minutes or more. If the determination in step S28 is No, stratified combustion is prohibited (step S31).

If the determination in step S28 is Yes,
The stratified combustion prohibition is canceled (step S30), and the process returns to the main routine. Thereafter, the stratified combustion of the engine can be performed if the normal stratified combustion conditions of medium-low load and medium-low rotation are permitted.

FIG. 5 is a flowchart for explaining the operation of the torque reduction amount determining section 30 of the engine C / U 8.
The torque-down amount determining unit 30 obtains the number of cylinders to be fuel-cut based on the required torque-down amount output from the torque-down control signal output unit 24 of the traction control C / U 7, and executes the fuel-cut operation of the fuel injection control unit 37. Notify the section 37a. The fuel cut execution unit 37a controls the injector 41 for each cylinder according to the notified number of fuel cut cylinders, so that traction control by fuel cut is realized.

In FIG. 5, first, it is determined whether there is a torque down request from the traction control C / U 7 (step S51). If there is no torque down request,
The fuel cut execution flag is reset (step S5
9) Return.

If it is determined in step S51 that there is a torque-down request, the required torque-down amount% is converted into the number of fuel cut cylinders with reference to the torque-down request amount / cylinder number conversion graph shown in FIG. 9 (step S51). S52). Next, the engine speed and the throttle opening are read (step S5).
3) A fuel cut time limit value is read out with reference to a fuel cut time limit map (not shown) (step S5).
4).

This fuel cut time limit map limits the time for continuously performing a fuel cut in which afterburning may occur in the catalyst in order to avoid an abnormal rise in the temperature of the exhaust gas purifying catalyst. When the fuel cut is performed for a predetermined time, the fuel cut pattern is limited to a fuel cut pattern in which the temperature of the catalyst does not increase for the predetermined time thereafter, thereby protecting the catalyst. The restriction of the fuel cut pattern is, for example, a restriction that fuel cuts are permitted only in the 0, 5, and 6 cylinders, and fuel cuts of other cylinders are not permitted. With this restriction, if the number of required fuel cut cylinders is one or two, the cylinder is changed to zero, and if the required number of cylinders is three or four, the number is changed to five.

Next, the fuel cut continuation time timer and the elapsed time after fuel cut end timer are read (step S5).
5), it is determined whether there is a fuel cut restriction (step S5).
6). If there is a fuel cut limit, the number of fuel cut cylinders is changed according to the limit (step S57), and if there is no fuel cut limit, step S57 is omitted. Next, a fuel cut execution flag is set, and a fuel cut is executed (step S58).

The fuel cut flag is a flag for controlling the fuel cut duration timer and the elapsed time after fuel cut end timer. While the fuel cut flag is set, the fuel cut duration timer counts and It is assumed that the elapsed time after the fuel cut has ended after the fuel cut flag is reset is controlled to count.

FIG. 6 is a flowchart for explaining the operation of a modification of the torque down amount determining section 30 of the engine C / U 8. The difference between the control flow shown in FIG. 6 and the control flow shown in FIG. 5 lies in that a function of distributing and controlling the required amount of torque reduction between the throttle opening control amount and the fuel cut control amount has been added. Is almost the same as in FIG.

That is, in the present modified example, the torque down request amount given from the torque down control signal output unit 24 to the torque down amount determination unit 30 in FIG. The traction of FIG. 2 is divided into a throttle opening control for the intake air amount control regarded as a low-speed response and a fuel cut control as a high-speed response which responds relatively quickly. The traction control is realized by instructing the control throttle control unit and the fuel cut execution unit 37a.

In FIG. 6, first, it is determined whether there is a torque down request from the traction control C / U 7 (step S71). If there is no torque down request,
Return without doing anything.

If it is determined in step S71 that there is a torque down request, the required amount of torque down is distributed to the throttle control component for the low frequency component and the fuel cut control component for the high frequency component (step S72). ). This distribution includes, for example,
There is a method of referring to the change history of the required torque down amount up to the present time and the immediately preceding distribution result.

Next, the required amount of torque reduction for the fuel cut control is converted into the number of cylinders with reference to, for example, the required torque reduction amount / cylinder conversion graph of FIG. 9 (step S7).
Along with 3), the required amount of torque reduction for the throttle control is converted into a throttle opening (step S81). The result of the conversion of the throttle opening is transferred to a throttle opening control unit (not shown).

After step S73, it is determined whether there is a fuel cut request (step S74). If there is no fuel cut request, the fuel cut execution flag is reset (step S82), and the process returns to the main routine. I do.

If there is a fuel cut request, the engine speed and the throttle opening are read (step S75), and the same processing as steps S54 (= step S76) to S58 (= step S80) in FIG. Do.

The effect of this modification is that the torque shock at the time of switching can be further reduced by precisely controlling the supply state of air and fuel when the air-fuel ratio is switched from stratified to homogeneous. It further stabilizes the condition and facilitates avoiding engine misfire conditions.

As for the torque down control method,
In addition to the air amount reduction and the fuel cut, the ignition timing may be retarded and the like may be used in combination.

[Brief description of the drawings]

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

FIG. 2 is a control block diagram of the traction control device of the embodiment.

FIG. 3 is a flowchart illustrating an operation of a traction control C / U of the embodiment.

FIG. 4 is a flowchart illustrating a stratified combustion inhibiting operation of the engine C / U of the embodiment.

FIG. 5 is a flowchart illustrating a fuel cut operation of the engine C / U of the embodiment.

FIG. 6 is a flowchart illustrating a torque down operation of an engine C / U according to a modified example of the embodiment.

FIG. 7 is a graph showing an engine generated torque map.

FIG. 8 is a graph showing an example of a low μ determination region based on a generated torque and a slip amount of an engine.

FIG. 9 is an example of a graph for converting a required torque reduction amount% to a fuel cut cylinder number, and shows a case of a six-cylinder engine.

[Explanation of symbols]

Reference Signs List 3 front right wheel speed sensor 4 front left wheel speed sensor 5 rear right wheel speed sensor 6 rear left wheel speed sensor 7 traction control C / U 8 engine C / U 9 engine water temperature sensor 12 throttle actuator 12a traction control throttle opening sensor Reference Signs List 20 wheel speed detection section 21 wheel speed comparison calculation section 22 slip amount calculation section 23 torque down amount calculation section 30 torque down amount determination section 31 timer count section after executing torque down 34 stratified combustion prohibition determination section 35 timer count section after warm-up 36 Homogeneous / stratified combustion switching section

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Claims (7)

[Claims] The present invention detects a slip amount of a drive wheel from a rotational speed of each wheel of a vehicle equipped with an engine capable of performing homogeneous combustion and stratified combustion, and based on the slip amount and a torque amount generated by the engine. A traction control method of calculating a torque reduction amount for suppressing a slip and performing fuel cut at least for each cylinder of the engine based on the torque reduction amount, wherein the slip amount is a predetermined value or more. A traction control method characterized by not performing stratified combustion of an engine. 2. A method for detecting a slip amount of a drive wheel from a rotational speed of each wheel of a vehicle equipped with an engine capable of performing homogeneous combustion and stratified combustion, and based on the slip amount and a torque amount generated by the engine. A traction control method of calculating a torque reduction amount for suppressing a slip and performing a fuel cut at least for each cylinder of the engine based on the torque reduction amount, wherein a time when the slip amount converges to a predetermined value or less. A traction control method, wherein stratified combustion of the engine is not performed when the time is within a first predetermined time. 3. A slip amount of a drive wheel is detected from a rotation speed of each wheel of a vehicle equipped with an engine capable of performing homogeneous combustion and stratified combustion, and based on the slip amount and a torque amount generated by the engine. A traction control method for calculating a torque reduction amount for suppressing a slip and performing a fuel cut at least for each cylinder of the engine based on the torque reduction amount, wherein the slip amount is reduced within a second predetermined time. A traction control method, wherein stratified combustion of the engine is not performed until a third predetermined time elapses from the time when the number of times exceeding the value reaches the predetermined number. 4. The traction control method according to claim 1, wherein the stratified combustion of the engine is not performed when the cooling water temperature history does not satisfy a predetermined condition. . 5. The traction according to claim 1, wherein the predetermined value of the slip amount is a speed difference between a driven wheel and a drive wheel of 20 to 30 km / h. Control method. 6. The traction control method according to claim 3, wherein the first predetermined time is shorter than the second predetermined time. 7. An engine capable of homogeneous combustion and stratified combustion, wheel speed detecting means for detecting the rotational speed of each wheel of the vehicle, and driving based on the speed of each wheel detected by the wheel speed detecting means. A slip amount calculating means for calculating a slip amount of the wheel; and a torque down calculating means for calculating a torque down amount for suppressing the slip based on the slip amount calculated by the slip amount calculating means and the torque amount generated by the engine. Fuel calculation control means for performing fuel cut for each cylinder of the engine based on the torque reduction amount calculated by the torque reduction amount calculation means, a water temperature sensor for detecting a cooling water temperature of the engine, The first predetermined amount is set when the slip amount is equal to or more than a predetermined value or when the slip amount converges to the predetermined value or less. That the number of times the slip amount exceeds the predetermined value within the second predetermined time is equal to or more than a predetermined number, or that the history of the cooling water temperature does not satisfy a predetermined condition. A traction control device, comprising: combustion mode control means for controlling so that stratified combustion of the engine is not performed when any one of them is detected.