JP2912012B2 - Vehicle slip control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle slip control device.

(Prior Art) In order to prevent the driving wheels from slipping due to excessive driving torque and deteriorating the acceleration when the vehicle is accelerating, the slip value of the driving wheels is detected, and the slip value of the driving wheels is set to a target value. Traction control that controls the application of the braking force to the engine output or the wheels (reducing the engine output or increasing the braking force) so as to obtain a value is generally known.

Further, there is known a proposal in which an anti-skid brake control device is provided with a G sensor for detecting a lateral acceleration of a vehicle, and corrects a braking target value of left and right wheel speeds or wheel decelerations according to the lateral acceleration. See Japanese Patent Publication No. 63-66703).

(Problems to be Solved by the Invention) By the way, when the vehicle turns, the drive wheels are likely to slip. On the other hand, in such a situation, lateral acceleration is generated in the vehicle. Therefore, in a vehicle equipped with slip control (traction control device), the lateral acceleration is detected, and the larger the value, the earlier the slip control is started. Alternatively, by increasing the control amount, it is possible to prevent a large slip from occurring.

However, it is necessary to provide a G sensor for detecting the lateral acceleration.

On the other hand, it is generally known that the lateral acceleration can be calculated based on the vehicle speed and the turning radius of the vehicle. Therefore, it is conceivable to calculate the lateral acceleration by calculation instead of using the G sensor. However, the vehicle is not necessarily placed so that the lateral acceleration is detected based on the actual turning radius of the vehicle and the slip control is corrected. Slip control suitable for the current situation cannot be performed.

That is, for example, in turning, when the vehicle speed is high, when the steering angle is large, or when the road surface friction coefficient is low, the actual turning line of the vehicle tends to deviate from the line intended by the driver, That is, the tendency of understeering (hereinafter, simply referred to as understeering) increases. In such a case, the slip control may be started earlier than usual or the control amount may be increased, but the actual turning radius of the vehicle increases when there is an understeer tendency, and the lateral acceleration obtained by the calculation decreases accordingly. Therefore, it is not always possible to start the slip control early as required or to increase the control amount as required.

That is, an object of the present invention is to make a correction suitable for a situation in which a vehicle is placed in performing a slip control correction by calculating a lateral acceleration of a vehicle without using a G sensor. is there.

(Means for Solving the Problems) In order to solve such a problem, the present invention, when calculating the lateral acceleration of the vehicle for correcting the slip control, corresponds to the actual turning radius and the steering angle of the vehicle. The turning radius of the vehicle is properly used depending on the tendency of the actual traveling line of the vehicle to deviate from the turning traveling line intended by the driver.

That is, a specific means for that includes a slip control means for controlling the driving of the drive wheels so that the slip amount becomes a target value when the slip amount of the drive wheels relative to the road surface exceeds a predetermined threshold value. In a vehicle slip control device, a vehicle speed detecting means for detecting a vehicle speed, a driven wheel speed detecting means for detecting a wheel speed of left and right driven wheels, a steering angle detecting means for detecting a steering angle, and the driven wheel speed An actual turning radius calculating means for obtaining an actual turning radius Rr of the vehicle based on a difference between the wheel speeds of the two driven wheels detected by the detecting means; and a steering angle detected by the steering angle detecting means in advance. Steering angle corresponding turning radius calculating means for obtaining a turning radius Ri of the vehicle set in accordance with the steering angle; a vehicle speed detected by the vehicle speed detecting means; an actual turning radius Rr calculated by the actual turning radius calculating means; A lateral acceleration calculating means for calculating a lateral acceleration of the vehicle based on one of the turning radii selected from the steering angle corresponding turning radii Ri calculated by the steering angle corresponding turning radius calculating means; Means for correcting the threshold value or the target value such that the value decreases as the lateral acceleration increases, based on the lateral acceleration calculated by the means; and at least one of a road surface state and a driving state of the vehicle. Based on the state, the magnitude of the tendency to deviate from the travel line at the steering angle-corresponding turning radius Ri when the vehicle turns is determined, and as the turning radius for the lateral acceleration calculation by the lateral acceleration calculating means, the above tendency is determined. Turning radius selecting means for selecting the steering angle corresponding turning radius Ri when it is large, and selecting the actual turning radius Rr when the above tendency is not large. That.

In this case, when selecting the turning radius, when the steering angle or the vehicle speed detected by the steering angle sensor is equal to or more than a predetermined value, the steering angle corresponding turning radius Ri is selected, and the steering angle or the vehicle speed is less than the predetermined value. When the actual turning radius Rr can be selected, or when the road surface friction coefficient is equal to or less than a predetermined value, the steering angle corresponding turning radius Ri is selected, and when the friction coefficient is larger than the predetermined value, the actual turning radius is determined. Can be selected.

(Operation) In the slip control device, when the vehicle has a large tendency to deviate from the travel line at the steering angle corresponding turning radius Ri when the vehicle turns, for example, when the understeer tendency is large, the steering angle corresponding turning radius Ri is used. Thus, the lateral acceleration of the vehicle is calculated. In this case, when such a tendency is large, the steering angle corresponding turning radius Ri is smaller than the actual turning radius Rr.
The calculated lateral acceleration increases, and the threshold value or the target slip value for determining whether or not to execute the slip control decreases.

Therefore, the slip control can be started early, or the control amount can be increased in order to reduce the slip amount to a low target value, and the driving torque of the drive wheels decreases early,
Alternatively, by increasing the amount of decrease, the understeering tendency can be suppressed by utilizing the decelerating action of the vehicle and the property of the understeer itself (the turning radius decreases as the vehicle speed decreases). In particular, in the case of a front-wheel drive vehicle, a change in the moment around the center of gravity of the vehicle caused by a sudden change in the forward force of the front wheels, and a recovery of the cornering force reduced by the driving force,
The understeer tendency can be positively and promptly eliminated.

On the other hand, when the vehicle turns, the turning radius Ri
When the tendency to deviate from the running line at the time is not great, the request for early start of the slip control or the increase of the control is relatively small, so the lateral acceleration is calculated using the actual turning radius Rr. By correcting the slip control based on the substantially accurate lateral acceleration based on the actual turning radius Rr, it is possible to prevent a large slip from occurring.

(Effects of the Invention) Therefore, according to the present invention, means for calculating the actual turning radius Rr, means for calculating the steering angle-corresponding turning radius Ri, and means for calculating the vehicle lateral acceleration based on the vehicle speed and the turning radius And means for correcting a threshold value or a control target value of the slip control according to the lateral acceleration. When the vehicle has a large tendency to deviate from the travel line at the steering angle corresponding turning radius Ri when the vehicle turns, the steering angle The lateral acceleration is calculated from the corresponding turning radius Ri, and when the above tendency is not large, the lateral acceleration is calculated from the actual turning radius Rr. When the above tendency is large, the steering angle corresponding turning radius Ri is calculated while accurately correcting the threshold value or the target value of the slip control.
The lateral acceleration is calculated to increase the decrease in the threshold value or the target value, and the early start of the slip control or the increase in the control amount prevents, for example, the vehicle from exhibiting an excessive understeer tendency beforehand. The turning traveling line of the vehicle can be brought closer to the line intended by the driver without performing a complicated steering operation.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

 FIG. 1 shows the overall configuration of the embodiment.

First, in the vehicle, the left and right front wheels 2FL, 2FR are set as drive wheels,
The left and right rear wheels 2RL, 2RR are driven wheels. That is,
A V-type 6-cylinder engine 1 is mounted at the front of the vehicle body. The generated torque of the engine 1 passes through an automatic transmission 3 and a differential device 4 and then to a left front wheel 2FL via a left drive shaft 5L and to a right drive shaft. 5R
Via the right front wheel 2FR.

When the slip amount of the drive wheels 2FL, 2FR with respect to the road surface exceeds a predetermined threshold value, the vehicle controls the drive of the drive wheels 2FL, 2FR so that the slip amount becomes a target value. Correction means 11 for correcting the threshold value and the target value in accordance with the lateral acceleration of the vehicle.
And

The control means 8 includes a brake sensor for detecting whether or not a brake is applied to the four wheels 2FL, 2FR, 2RL, 2RR, a steering angle sensor for detecting a steering angle of the steering wheel of the vehicle,
Wheel speed sensor 9FL, 9FR, 9 that detects the wheel speed of 2FR, 2RL, 2RR
RL, 9RR, signals from an engine speed sensor for detecting the engine speed, etc. are input, and signal processing is performed to generate an ignition timing control signal and a fuel injection limit signal for reducing the output torque of the engine 1. Output.

Further, for the lateral acceleration corresponding correcting means 11, an actual turning radius calculating means 12 for calculating an actual turning radius Rr of the vehicle, a steering angle corresponding turning radius calculating means 13 for calculating a turning radius Ri corresponding to the steering angle, A lateral acceleration calculating means 14 for calculating the lateral acceleration G of the vehicle, and a turning radius selecting means 15 for selecting a turning radius used for calculating the lateral acceleration from the actual turning radius Rr and the turning angle corresponding turning radius Ri are provided. I have.

Hereinafter, the lateral acceleration corresponding correction means 11 and the control means 8 will be specifically described in this order.

<Correction corresponding to lateral acceleration>-Actual turning radius Rr-The actual turning radius calculating means 12 calculates the actual turning radius Rr based on the wheel speeds VRL, VRR of the driven wheels 2RL, 2RR detected by the wheel speed sensors 9RL, 9RR as follows. The calculation is performed according to the equation (1).

− (1) − Rr = Min (VRL, VRR) × TVR | VRL−VRR | + 1/2 × T In this case, Min (VRL, VRR) is the both driven wheel speeds VRL, VR.
It means the smaller wheel speed of R. Also, | VRL-VRR
| Is the absolute value of the difference between the two wheel speeds VRL and VRR, and T is the tread (eg, 1.7 m) of the vehicle.

The steering angle-corresponding turning radius Ri- The steering angle-corresponding turning radius calculation means 13 is based on the absolute value of the steering angle θH detected by the steering angle sensor 7 and is set in advance in a manner corresponding to the steering angle in a unified manner. The turning radius Ri (corresponding substantially to the turning radius in neutral steering) corresponding to the steering angle is obtained by linear interpolation from the Ri table.

-Calculation of lateral acceleration-The lateral acceleration calculating means 14 calculates the lateral acceleration G of the vehicle according to the following equation (2) based on the vehicle speed Vr as the vehicle speed and the turning radius R of the vehicle.

G = Vr ² × (1 / R) × (1/127) In this case, the vehicle speed detection means 16 detects the vehicle speed Vr.
Detects the higher one of the wheel speeds VRL, VRR of the driven wheels detected by the wheel speed sensors 9RL, 9RR as the vehicle body speed. The turning radius R is selected from the actual turning radius Rr and the turning radius corresponding to the steering angle Ri by the turning radius selecting means 15 described later.

-Correction for lateral acceleration-Correction means for lateral acceleration 11 is
A correction coefficient k for correcting the slip determination threshold value and the control target value such that the value decreases as the lateral acceleration increases, based on the lateral acceleration G calculated by
This is output to the slip determination threshold value setting means and the control target value setting means described later.

In this case, the lateral acceleration correction means 11 includes a next correction coefficient table in which the lateral acceleration of the vehicle is set in advance as a parameter, and calculates the correction coefficient based on this table.

-Turning radius selection-The turning radius selecting means 15 provides a steering angle corresponding turning radius when the vehicle turns, based on the road surface condition and the driving condition of the vehicle.
The magnitude of the tendency to deviate from the running line at Ri is determined, and the turning radius R for calculating the lateral acceleration by the lateral acceleration calculating means 14 is used.
When Ri is selected and the above tendency is not large, the actual turning radius
Select Rr.

Specifically, the determination is made based on the steering angle θH detected by the steering angle sensor 7 and the vehicle speed detected by the vehicle speed detection means 16.
Vr and the friction coefficient μ detected by the road surface friction coefficient detecting means 17, and the absolute value of the steering angle θH is set to a predetermined value θ.
When the condition that the vehicle speed Vr is equal to or greater than Ho, the condition that the vehicle speed Vr is equal to or greater than the predetermined value Vro, and the condition that the friction coefficient μ is equal to or less than the predetermined value μo are satisfied, the steering angle-corresponding turning radius Ri is selected. If the two are not established, the actual turning radius Rr is selected.

—Road surface friction coefficient μ— The road surface friction coefficient detecting means 17 calculates based on the vehicle speed Vr and the acceleration VG of the vehicle speed Vr.

A timer A (100 msec count) and a timer B (500 msec count) are used to calculate the vehicle body acceleration VG. That is, the vehicle acceleration VG is 500 mse from the start of the slip control.
Until c (body acceleration is not large enough), 100ms
The vehicle speed Vr for 100 msec for each ec (in this example, the higher wheel speed of the two wheel speeds of the rear wheels 2RL and 2RR which are driven wheels, unit;
km / h), 500mse
After elapse (body acceleration is fully developed), 500m every 100msec
It is obtained by the following equation (4) based on the change in the vehicle speed Vr during the sec.

− (3) −VG = Gk1 × {Vr (k) −Vr (k−100)} − (4) −− VG = Gk2 × {Vr (k) −Vr (k−500)} The above Gk1 and Gk2 Is a coefficient. Vr (k) is at the present time, Vr (k−100) is 100 ms before, Vr (k−500) is 500 ms
It is each vehicle speed before ec.

Then, from the vehicle acceleration VG and the vehicle speed Vr calculated as described above, the road surface friction coefficient μ is obtained by three-dimensional interpolation using the following μ table.

FIG. 2 shows the flow of the lateral acceleration corresponding correction control.

That is, data on the driven wheel speeds VRL and VRR and the steering angle θH are input, a condition that the absolute value of the steering angle θH is equal to or more than a predetermined value θHo, a condition that the vehicle speed Vr is equal to or more than a predetermined value Vro,
When the condition that the friction coefficient μ is equal to or less than the predetermined value μo is satisfied, a lateral acceleration G is calculated from the turning angle corresponding turning radius Ri, a correction coefficient k is calculated based on the lateral acceleration G, and a slip determination threshold value is calculated. And the control target value is corrected (step
S1 to S6). On the other hand, when any one of the above three conditions is not satisfied, a lateral acceleration G is calculated from the actual turning radius Rr (step S7), and a correction coefficient k is calculated based on the lateral acceleration G to calculate a slip determination threshold value. And the control target value is corrected.

<Control Means> The control means 8 includes an input interface for receiving signals from each sensor, a microcomputer including a CPU, a ROM, and a RAM, an output interface, and a drive circuit for driving the igniter and the fuel injection device. The ROM is provided with a control program and various maps or tables required for slip control, and the RAM is provided with various memories required for executing control. And this control scheme 8
As shown in FIG. 3, a slip determination threshold setting means 32, a slip amount calculation means 33, a slip determination means 34,
A control target value setting unit 35, a control level calculating unit 36, and an engine output control unit 37 are provided.

[Setting of Slip Determination Threshold] The slip determination threshold is for determining whether or not the slip control is required. The slip determination threshold setting means 32 calculates the slip speed based on the vehicle speed Vr and the road surface friction coefficient μ. The basic threshold is calculated by three-dimensional interpolation using the following threshold tables 1 and 2, and the threshold is set based on the following equation (5) using the correction coefficient k obtained by the lateral acceleration corresponding correction means 10. is there.

-(5) formula- The threshold table 1 is for determining whether to start the slip control, and the threshold table 2 is for determining whether to continue the slip control.

[Slip Calculation] As shown in FIG. 4, the slip calculator 33 includes an actual slip calculator 45, an average slip calculator 48, and a maximum slip calculator 49.

The actual slip amount calculating means 45 subtracts the vehicle speed Vr from the wheel speeds VFL, VFR of the left and right front wheels 2FL, 2FR to obtain slip amounts SL, SR of these two wheels. The average slip amount calculating means 48
Is the average slip amount S based on the slip amounts SL and SR.
Av is calculated, and the maximum slip amount calculating means 49 calculates the higher one of the two slip amounts SL and SR as the maximum slip amount SHi.

[Slip Determination] The slip determination means 34 determines that the slip control is necessary when the following equation (6) is satisfied, and sets the slip flag SFL to 1, based on the maximum slip amount SHi and the threshold value for slip determination. -(6)-SHi≥Slip determination threshold In this case, the slip determination threshold is determined by the slip control determination means 66 described later in a non-control state (CFL = 0).
Is determined, the threshold based on the threshold table 1 (for start) described above is used, and when slip control is determined (CFL = 1), the threshold based on the threshold table 2 (for continuation) is used. Is used.

[Setting of Control Target Value] The control target value T is a target value as the slip amount of the front wheels 2FL and 2FR. The control target value calculating means 35 calculates the following based on the vehicle speed Vr and the road surface friction coefficient μ. The control target basic value is calculated by three-dimensional interpolation from the control target value table of FIG.
The control target value is set based on the following equation (7).

−Equation (7) − T = Control target basic value × k [Control Level Calculation] The control level FC is determined on the basis of the deviation EN of the average slip amount SAv from the control target amount T and the rate of change DEN of this deviation. The feedback correction and the initial value correction are added and set in the range of 0 to 15. For this purpose, as shown in FIG. 5, a deviation calculating means 60, a deviation change rate calculating means 61, a basic control level calculating means 62, a feedback correcting means 63, an initial correction amount calculating means 64, a final control level Calculation means 65 are provided.

The deviation calculating means 60 calculates the deviation EN by subtracting the control target value T from the average slip amount SAv.

The deviation change rate calculation means 61 calculates the average slip amount change rate DSAv based on the following equation (8), and sets this as the deviation change rate DEN.

DSAv = SAv (K) -SAv (K-1) The basic control level calculation means 62 converts the basic control level FCB to the next basic control level based on the deviation EN and the deviation change rate DEN. This is calculated using a table.

The feedback correction means 63 determines that the current control level FC
The control level FC (K-1) of the previous operation is added to (K).

The initial correction amount calculating means 64 forcibly increases the control level from when the slip of the front wheels is determined for the first time to when the first slip determination is eliminated. For this purpose, the slip control shown in FIG. A determining means 66 and an initial slip control determining means 67 shown in FIG. 7 are provided.

In FIG. 6, reference numeral 68 denotes an AND circuit for outputting a set signal to the flip-flop 69 when the slip flag SFL = 1 and in the non-braking state, and reference numeral 70 denotes FC ≦ 3 and DSAv ≦ 0.3
The AND circuit 71 whose output becomes 1 at the time of g, receives the signal of the slip flag SFL = 0 through the counter 72 continuously for 1000 msec, or the AND circuit 70 through the counter 73.
This is an OR circuit that outputs a reset signal to the flip-flop 69 when the output signal 1 is continuously received for 500 msec. When receiving the set signal, the flip-flop 69 outputs a signal of the control flag CFL = 1 (during slip control).

In FIG. 7, reference numeral 74 denotes the current control flag CFL.
(K) = 1 and previous control flag CFL (K−1) = 0
Outputs a set signal to flip-flop 75 when
The D circuit 76 is an AND circuit that outputs a reset signal to the flip-flop 75 when the current slip flag SFL (K) = 0 and the previous slip flag SFL (K−1) = 1. The flip-flop 75 receives the set signal and outputs a signal of the initial flag STFL = 1 (during initial control).

The first correction amount calculating means 64 receives the first flag STFL signal and the average slip amount change rate DSAv, and sets STFL = 1 and
When DSAv ≥ 0, the first correction amount (+5) is calculated and output, and STFL
= 1 and DSAv <0, the first correction amount (+2) is calculated and output.

The final control level calculation means 65 adds the first correction amount to the feedback corrected control level FC.

[Output Control] -Ignition Timing Control- As for the ignition timing, as shown in FIG. 8, the retard amount is determined according to the above control level and output. In this case, as shown in FIG. 9, the maximum retard amount is limited in a region where the engine speed is high.

-Restriction of fuel injection (fuel cut)-Restriction of fuel injection is performed by selecting patterns 0 to 12 of the next fuel cut table based on the above control level (selecting a pattern with a higher value as the level increases). In this case, as shown in FIG. 10, a fuel cut prohibition condition is set for each control level so that the fuel cut is restricted in a region where the engine speed is low. It should be noted that x in the above table means a fuel injection cut.

FIG. 11 shows the flow of the slip control.

That is, the threshold value for the slip control start determination for shifting from the non-control state to the slip control is calculated based on the basic value table for start, and a relatively high threshold value (corresponding to Sh in FIG. 11). ). Therefore, even if the wheel speed of the driving wheel becomes high (the maximum slip amount SHi becomes large) due to disturbance or the like, the slip flag SFL does not rise and control is not started unless the threshold Sh is exceeded. When the drive wheel speed exceeds the threshold value Sh, the slip flag SF
If L is on and the brake is inactive, control flag C
FL and initial flag STFL are set. Thereby, the slip control is started.

In the turning operation of the vehicle, the steering angle θH, the vehicle speed Vr
When it is determined from the value of the road surface friction coefficient μ and the tendency to deviate from the traveling line at the steering angle-corresponding turning radius Ri (for example, the understeer tendency is large), the vehicle is moved laterally using the steering angle-corresponding turning radius Ri. The acceleration G is calculated. In this case, since the steering angle-corresponding turning radius Ri is smaller than the actual turning radius Rr, the obtained lateral acceleration G increases and the correction coefficient k decreases, so that the control start determination threshold value decreases.

Therefore, even if the slip amount itself is not so large,
Since the slip control is started early, it is possible to suppress the excessive decrease in the driving torque of the driving wheels before an excessive understeering tendency occurs.

In the slip control, the average slip amount SAv is calculated based on the front wheel speeds VFL, VFR and the vehicle speed Vr, while the control target value T is set based on the vehicle speed Vr and the road surface friction coefficient μ. The basic control level is set based on the deviation EN of the average slip amount SAv from the control target value T and the rate of change DEN of the deviation, and the control level FC is obtained by performing initial correction on the basic control level. , This control level FC
The ignition timing control and the fuel injection restriction control according to the above are performed.

The initial correction is (+5) until the rate of change DSAv of the average slip amount becomes zero for the first time.
Is (+2) until is becomes zero. By this initial correction, the control amount is forcibly increased, and early convergence of the slip can be achieved.

The initial flag STFL becomes 0 when the maximum slip amount SHi based on the higher drive wheel speed becomes equal to or less than the threshold value for determining whether to continue the slip control.

However, when it is determined that the vehicle tends to deviate from the travel line at the steering angle-corresponding turning radius Ri in the turning operation of the vehicle, the control target value T decreases due to the decrease in the correction coefficient k as described above. , As a result, this target value T
The understeer tendency can be eliminated by increasing the amount of reduction in the drive torque of the drive wheels in order to reduce the slip amount.

The threshold for the continuation determination (corresponding to S1 in FIG. 11) is
The base value is calculated by the base value table for continuation,
It is set to a relatively low threshold. Also, the turning radius corresponding to the steering angle
When it is determined that the tendency to deviate from the traveling line at Ri is large, the correction coefficient k becomes small as described above. Therefore, the continuation determination threshold value is further reduced, and the control can be continued until the slip reliably converges.

On the other hand, when the vehicle turns, the turning radius Ri
When the tendency to deviate from the traveling line at is not large, the lateral acceleration G is calculated using the actual turning radius Rr. Therefore, the slip determination threshold value and the control target value T are accurately corrected to match the actual lateral acceleration. Will be done.

Then, even if the higher driving wheel speed becomes equal to or less than the continuation determination threshold S1, the control flag CFL remains set if the state does not continue for one second or more. Then, as the reduction amount of the drive wheel drive torque decreases, the drive wheel speed increases again. When the drive wheel speed exceeds the continuation determination threshold S1, the slip flag SFL is set again, and the control is continued. In this case, the initial flag STFL does not rise and the control level
There is no initial correction of FC. Therefore, the control level FC is initially set only at the basic control level based on the deviation EN and the deviation change rate DEN, and thereafter, a value obtained by adding the previous value to the basic control level by feedback correction is set as the control level FC. Will go.

As described above, when the slip converges and the state where the slip flag SFL does not stand for 1 second or more continues, the control flag CFL becomes 0, and this series of slip control ends.

In the above embodiment, both the slip determination threshold value and the control target value are corrected with the same correction coefficient. However, the correction may be performed with different correction coefficients, or only one of them may be corrected. You may do so. Further, only the slip control start threshold value may be corrected.

Further, the determination by the turning radius selection means includes the vehicle speed, the steering angle,
The determination may be performed based on any one of the road surface friction coefficients.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is an overall configuration diagram of a vehicle slip control device, FIG. 2 is a flowchart of lateral acceleration corresponding correction control, FIG. 3 is a configuration diagram of slip control means, FIG.
FIG. 5 is a block diagram of the slip amount calculating means, FIG. 5 is a block diagram of the control level calculating means, FIG. 6 is a block diagram of the slip control determining means, FIG. 7 is a block diagram of the initial slip control determining means, FIG. Is a characteristic diagram showing the relationship between the control level and the ignition timing retard amount, FIG. 9 is a characteristic diagram showing the restriction of the ignition timing retard amount by the engine speed, and FIG. 10 is a characteristic diagram showing the fuel cut restriction region by the engine speed. FIG. 11 is a time chart of the slip control. 1 Engine 2FL, 2FR Front wheel (drive wheel) 2RL, 2RR Rear wheel (driven wheel) 7 Steering angle sensor 8 Control means 9FL-9RR Wheel speed sensor 11 Supports lateral acceleration Correction means 12 Actual turning radius calculating means 13 Steering angle corresponding turning radius calculating means 14 Lateral acceleration calculating means 15 Turning radius calculating means 16 Vehicle speed detecting means 17 Road surface friction coefficient detecting means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 29/02 F02D 45/00

Claims (4)

(57) [Claims] 1. A slip control device for a vehicle, comprising: slip control means for controlling the driving of the drive wheels such that the slip amount becomes a target value when the slip amount of the drive wheels relative to the road surface exceeds a predetermined threshold value. A vehicle speed detecting means for detecting a vehicle speed, a driven wheel speed detecting means for detecting a wheel speed of left and right driven wheels, a steering angle detecting means for detecting a steering angle, and a wheel angle detected by the driven wheel speed detecting means. Actual turning radius calculating means for obtaining an actual turning radius Rr of the vehicle based on the difference between the wheel speeds of the two driven wheels, and a steering angle previously determined based on the steering angle detected by the steering angle detecting means. Steering angle corresponding turning radius calculating means for obtaining the turning radius Ri of the set vehicle, the vehicle speed detected by the vehicle speed detecting means, the actual turning radius Rr calculated by the actual turning radius calculating means, and the steering angle corresponding turning. Radius performance Means for calculating the lateral acceleration of the vehicle based on one of the turning radii Ri selected from the turning radii Ri calculated by the means; and the lateral acceleration calculated by the lateral acceleration calculating means. A correction means for correcting the threshold value or the target value so that the value becomes lower as the lateral acceleration becomes larger, and a vehicle based on at least one of a road surface state and a vehicle driving state. When turning, the magnitude of the tendency to deviate from the travel line at the steering angle-corresponding turning radius Ri is determined. The turning radius for calculating the lateral acceleration by the lateral acceleration calculating means is used. A turning control device for a vehicle, comprising: turning radius selecting means for selecting Ri and selecting the actual turning radius Rr when the tendency is not large. 2. The turning radius selecting means selects a turning angle corresponding turning radius Ri when the steering angle detected by the steering angle detecting means is equal to or greater than a predetermined value, and when the steering angle is less than the predetermined value. The vehicle slip control device according to claim 1, wherein the actual turning radius Rr is selected. 3. The turning radius selecting means, when the vehicle speed detected by the vehicle speed detecting means is equal to or higher than a predetermined value, a turning radius corresponding to the steering angle.
The vehicle slip control device according to claim 1, wherein Ri is selected, and the actual turning radius Rr is selected when the vehicle speed is less than the predetermined value. 4. A road surface friction coefficient detecting means for detecting a friction coefficient between a tire of a wheel and a road surface, wherein the turning radius selecting means has a friction coefficient detected by the road surface friction coefficient detecting means of not more than a predetermined value. When selecting the turning radius corresponding turning radius Ri,
The vehicle slip control device according to claim 1, wherein the actual turning radius Rr is selected when the coefficient of friction is larger than the predetermined value.