JP2903804B2 - Traction control device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traction control device for a vehicle that performs hydroplane countermeasure control when detecting a hydroplane state generated by a water film between a tire and a road surface during running.

[0002]

2. Description of the Related Art Conventionally, as this kind of traction control device for a vehicle, for example, a device described in Japanese Patent Application Laid-Open No. Sho 64-60463 is known.

According to this conventional source, in a traction control system using both a throttle and a brake, a hydroplane state is detected when the deceleration of a driven wheel speed sensor value is large at a high vehicle speed and the hydroplane state is detected. In such a case, a technique for prohibiting only the brake control as a measure against the hydroplane is disclosed.

[0004] This is determined to be a slip state based on the relationship between the driving wheel speed and the driven wheel speed, but this is because the slip is not an actual acceleration slip but a pseudo slip.

[0005]

However, in such a conventional vehicle traction control device, the brake control is prohibited even if the accelerator pedal is depressed in the hydroplane state. When the vehicle enters the plane state, as shown in FIG. 10, the driven wheel rapidly decelerates (braking slip state), the driving wheel rapidly increases in speed (acceleration slip state), and the tires grip the driven wheel and the driving wheel. And vehicle stability is reduced. Therefore,
In order to suppress the acceleration slip of the drive wheels, a highly responsive berake control is required.

Therefore, a case is considered in which brake control is performed with a normal control gain in the hydroplane state. First, in the hydroplane state, as shown in FIG.
Acceleration slip condition is overestimated due to deceleration of driven wheel,
Excessive brake control. In addition, road surface resistance is low in the hydroplane state. On the other hand, when the brake control is performed with the normal control gain, the brake pressure becomes excessive as shown in FIG. 12, and the drive wheels tend to lock as shown by the thick dotted line characteristics in FIG. As a result, the stability of the driving wheels decreases. That is, both the driven wheel and the drive wheel are in a braking slip state, and the vehicle stability is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. A traction control apparatus for a vehicle that performs hydroplane countermeasure control when a hydroplane state is detected. It is an object to ensure good vehicle stability.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a vehicle traction control device according to the present invention, when detecting occurrence of an acceleration slip in a hydroplane state, reduces a braking force of a driving wheel by a brake control gain lower than usual. Control means.

That is, as shown in the claim correspondence diagram of FIG. 1, a driving wheel braking force control means a for controlling the braking force of the driving wheel.
A hydroplane detecting means b for detecting a hydroplane state; an accelerating slip detecting means c for detecting an accelerating slip condition of a driving wheel; and Control means d for outputting a brake control command with a brake control gain lower than the brake control gain in the traction control to said drive wheel braking force control means a.
It is characterized by having.

When a hydroplane state is detected, engine output control is performed to maintain the vehicle speed at that time, regardless of the occurrence of an acceleration slip. At the time of the occurrence of an acceleration slip, the hydroplane corresponding control by the brake control is performed. You may do it.

[0011]

When the vehicle enters a pool or the like during acceleration traveling, the hydroplane state is detected by the hydroplane detection means b, and when the acceleration slip of the driving wheel is detected by the acceleration slip detection means c, In the plane corresponding control means d, a brake control command with a brake control gain lower than the brake control gain in normal traction control is output to the driving wheel braking force control means a.

Therefore, when the acceleration slip occurs in the hydroplane state, the driving wheel speed converges to the vehicle speed with a good response by applying the brake pressure lower than the normal control, and the braking of the driving wheel does not occur. Acceleration slip is suppressed. As a result, the road surface grip is obtained on the driving wheel side, so that the vehicle stability is ensured.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration will be described.

FIG. 2 is an overall view of a braking / drive system control system for a rear wheel drive vehicle to which the vehicle traction control device according to the embodiment of the present invention is applied.

This rear-wheel drive vehicle has a throttle control for controlling a motor throttle opening degree so that a rear wheel slip ratio is within an optimum allowable range when an acceleration slip occurs, and is independent of right and left rear wheels when an acceleration slip occurs. A traction control system (the brake control side is equivalent to a driving wheel braking force control means) is used, which is used in combination with a brake control that applies braking force to the front and rear wheels. An anti-skid brake control system that performs control is mounted. Centralized electronic control of these systems is performed by a traction control system & anti-skid brake control system electronic control unit TCS / ABS-ECU (hereinafter abbreviated as TCS / ABS-ECU).

The TCS / ABS-ECU has a right front wheel speed sensor 1
From the right front wheel speed sensor value VWFR, the left front wheel speed sensor value VWFL from the left front wheel speed sensor 2, the right rear wheel speed sensor value VWRR from the right rear wheel speed sensor 3, and the Left rear wheel speed sensor value VWRL, lateral acceleration sensor value YG from lateral acceleration sensor 5, switch signal SWTC from TCS switch 6, switch signal SWST from brake lamp switch 7, throttle control module TCM (hereinafter, referred to as Throttle 1 actual opening DKV from TCM)
And the automatic transmission control unit A /
Gear position signal and shift-up signal from TC / U (hereinafter abbreviated as A / TC / U) and engine rotation from ECCS C / U (hereinafter abbreviated as ECCS C / U) A number signal, a second throttle signal TVO2 from the second throttle sensor 17, and the like are input.

From the TCS / ABS-ECU, an acceleration slip is detected and the throttle 2 as a throttle opening / closing signal is detected.
The target opening DKR is output to the TCM, and a solenoid signal as a brake pressure increase / decrease signal is output to each solenoid valve of the common hydraulic unit TCS / ABS-HU (hereinafter abbreviated as TCS / ABS-HU). (Traction control combined with throttle and brake). Also, a deceleration slip is detected, and a solenoid signal as a brake pressure increase / decrease signal is output to TCS /
Output to each solenoid valve of ABS-HU (anti-skid brake control).

In addition to the above output, the TCS / ABS-ECU outputs a lighting command to the TCS fail lamp 14 when the TCS fails, and outputs a lighting command to the TCS operating lamp 15 during the TCS operation.

The TCM is a control circuit mainly including a throttle motor drive circuit. The TCM receives the first throttle signal TVO1 from the first throttle sensor 16 and outputs it to the TCS / ABS-ECU as the throttle 1 actual opening degree DKV. Or input the second throttle signal TVO2 from the second throttle sensor 17 as feedback information to the throttle 2 target opening DKR, or input the throttle 2 target opening DK from the TCS / ABS-ECU.
A motor drive current IM is applied to the throttle motor 18 based on R.

Here, the first throttle valve 19 provided with the first throttle sensor 16 is connected to the accelerator pedal 2.
The second throttle valve 21 provided with the second throttle sensor 17 is provided in the engine intake passage 22 in series with the first throttle valve 19, and is opened / closed by the throttle motor 18. Valve.

The traction control system includes an air flow meter AFM as a peripheral system as shown in FIG.
And an ECCS C / U and an injector, and an engine centralized electronic control system that performs centralized control of fuel injection control, ignition timing control, idle speed correction, etc., is installed. When the ON signal is input, control (select low control) for selecting a smaller valve opening degree of the first throttle signal TVO1 and the second throttle signal TVO2 is performed for transient characteristic correction, and the canister control and the EGR control are performed. Aborted.

As shown in the figure, an automatic transmission control system which has an A / TC / U and a shift solenoid and performs shift control and lock-up control is mounted as a peripheral system. , The gear position signal and the shift-up signal are taken into the TCS / ABS-ECU.

Further, as a peripheral system, as shown, a constant speed traveling control system having an ASCD actuator and performing automatic vehicle speed control so as to maintain a set vehicle speed is mounted. When the ON signal of the traction switch signal TCS SW is input, the opening control of the first throttle valve 19 is stopped, and when the OFF signal of the TCS SW is input, the return speed of the first throttle valve 19 is reduced.

FIG. 3 is a hydraulic circuit diagram showing a brake fluid pressure control system commonly used for traction brake control and anti-skid brake control independent of the left and right rear wheels.

The brake fluid pressure control system comprises a brake pedal 27, a hydraulic booster 28, a master cylinder 30 having a reservoir 29, wheel cylinders 31, 32,
33, 34, shared hydraulic unit TCS / ABS-HU
, Pump unit PU, and first accumulator unit
AU1, second accumulator unit AU2, front wheel side damping unit FDPU, rear wheel side damping unit RD
With PU.

The TCS / ABS-HU has a first switching valve 35a.
, A second switching valve 35b, and a left front wheel pressure increasing valve 36a.
, A right front wheel pressure increasing valve 36b and a left rear wheel pressure increasing valve 36
c, right rear wheel pressure increasing valve 36d, left front wheel pressure reducing valve 3
7a, a right front wheel pressure reducing valve 37b, a left rear wheel pressure reducing valve 37c, a right rear wheel pressure reducing valve 37c, a front wheel side reservoir 38a, a rear wheel side reservoir 38b, and a front wheel side pump 39.
a, a rear wheel side pump 39b, and a front wheel side damper chamber 40a.
And a rear-wheel-side damper chamber 40b and a pump motor 41.

At the time of normal braking or anti-skid brake control, the two switching valves 35a and 35b are set to the OFF position as shown in the figure to introduce the hydraulic pressure from the master cylinder 30, and during traction brake control (traction control). At the time of brake control).
In order to introduce the hydraulic pressure from the accumulator unit AU2, both switching valves 35a and 35b are set to the ON position. For example, in the pressure increase mode in the traction brake control, both control valves 36c, 36d, 37c, 37d are used.
Are set to the OFF position as shown in the figure, only the pressure increasing valves 36c, 36d are set to the ON position in the holding mode, and both control valves 36c, 36d, 37c, 37d are set in the pressure reducing mode.
Is set to the ON position, and the brake fluid from the wheel cylinders 33 and 34 is stored in the rear wheel side reservoir 38b.
The rotation of the rear wheel side pump 39b causes the rear wheel side damper chamber 40 to rotate.
b.

The first accumulator unit AU1 comprises:
The second accumulator unit AU2 is used as a hydraulic pressure source for the traction brake control, and both units AU1 and AU2 are connected to the reservoir 29.
A predetermined accumulator pressure is maintained by a common pump unit PU that sucks brake fluid from the pump.

The front-wheel-side damping unit FDPU and the rear-wheel-side damping unit RDPU are provided with a shared hydraulic unit TCS / AB in order to improve pedal feeling.
The influence of the fluid pressure change in the S-HU on the master cylinder 30 is suppressed.

The operation will be described.

(A) Normal Traction Control Operation FIG. 4 is a control block diagram showing an outline of the traction control performed by the TCS / ABS-ECU. The traction control logic can be roughly divided into the following four types of control.

(1) Calculation of Actual Slip State Filter processing is performed on the signals of the wheel speed sensors 1, 2, 3, and 4, and based on the wheel speed values after the filter processing, the actual slip state (slip amount, slip amount difference value) is calculated. ) Is calculated.

(2) Calculation of Target Slip State Filter processing is performed on the signal of the lateral acceleration sensor 5 to calculate a target slip state suitable for the running state based on the determination of turning / straight running based on the lateral acceleration and the vehicle speed.

(3) Brake control A required brake increasing / decreasing speed (control duty ratio) is calculated by comparing the actual slip state and the target slip state, and is output to the TCS / ABS-HU.

(4) Throttle control Necessary throttle opening and opening / closing speed are calculated by comparing the actual slip state with the target slip state and output to the TCM.

The characteristics of this control logic are as follows:
In order to secure the limit detectability (steering force, skill sound, etc.) based on the base chassis performance according to each road surface condition that leads to active safety and to obtain active safety, the allowable slip state according to the magnitude of the lateral acceleration, The division of throttle / brake control is decided.

In order to ensure stability during shifting and to improve controllability at each gear position, throttle / brake control according to the gear position is performed.

Further, in order to realize smooth acceleration feeling and controllability while suppressing slip hunting, and to realize a responsive engine torque increase / decrease control, optimal throttle control according to the engine speed is performed.

(B) Hydroplane detection operation FIG. 5 is a flowchart showing the flow of the hydroplane detection processing operation performed in the TCS / ABS-ECU. Each step will be described below (corresponding to hydroplane detection means).

In step 50, the right front wheel speed sensor value VWFR from the right front wheel speed sensor 1 and the left front wheel speed sensor value VWFL from the left front wheel speed sensor 2 are filtered by a low-pass filter having a predetermined cutoff frequency. The front wheel speed filter value FVWFR and the left front wheel speed filter value FVWFL are set.

In step 51, the right front wheel speed filter value F
An upper limit value is set for VWFR and a front left wheel speed filter value FVWFL for the amount of change on the acceleration side and deceleration side, and a control front right wheel speed filter value VFTFR and a control front left wheel speed filter value VFTFL are created.

That is, at the time of acceleration slip, when the right front wheel speed filter value FVWFR or the left front wheel speed filter value FVWFL is smaller than the larger value of the left and right rear wheel speeds VWRR and VWRL which are the driving wheel speeds, as shown in FIG. , 10msec on the acceleration side
(10msec processing cycle) After holding, the maximum slope is regulated to + 0.4G, and on the deceleration side, 10msec is held for 2sec for -0.
Decelerate by 1G and then limit the slope to a maximum of -0.35G.

If the right front wheel speed filter value FVWFR or the left front wheel speed filter value FVWFL is larger than the left or right rear wheel speed VWRR, VWRL during deceleration slip,
As shown in FIG. 7, the inclination is restricted to a maximum of -1.13G on the deceleration side.

In step 52, a high pre-flag HYPF indicating whether or not the hydroplane is in effect is set to HYPF = 1.
(Hydroplane state) is determined.

When HYPF = 0, the routine proceeds to step 53, where the difference between the control front right wheel speed filter value VFTFR and the front right wheel speed sensor value VWFR is equal to or greater than a set value V0 (for example, 5 km / h) and It is determined whether the difference between the front left wheel speed filter value VFTFL and the front left wheel speed sensor value VWFL is equal to or greater than the set value V0.

When the condition of step 53 is satisfied, the routine proceeds to step 54, where the high pre-flag HYPF is set to HYPF = 1 indicating the hydroplane state.

On the other hand, if YES is determined in the step 52, the process proceeds to a step 55 in which a difference between the control right front wheel speed filter value VFTFR and the right front wheel speed sensor value VWFR is set to a set value V1.
(For example, 2 km / h) and it is determined whether or not the difference between the control front left wheel speed filter value VFTFL and the front left wheel speed sensor value VWFL is smaller than the set value V1.

If the condition is satisfied in step 55, the process proceeds to step 56, where the high pre-flag HYPF is cleared to HYPF = 0 assuming that the hydroplane state has been exited.

If the vehicle enters the hydroplane state during traveling, step 50 → step 51 → step 52
→ The flow proceeds to step 53 → step 54. When the high pre-flag HYPF = 1 is set and the state of the hydroplane is exited, step 50 → step 51
The flow proceeds from step 52 to step 55 to step 56, and the high pre-flag HYPF = 0 is cleared.

That is, when entering the hydroplane state,
The front wheel speed sensor values of the left and right front wheels, which are the driven wheels, show characteristics such that the left and right front wheels rapidly decelerate due to the water film resistance immediately after the entry, and thereafter the deceleration becomes moderate, as shown by the solid line characteristics in FIG. . On the other hand, the control front wheel speed filter value has a lower limit than the front wheel speed sensor value by having a common upper limit when a low-pass filter is applied, as shown by the one-dot chain line characteristic in FIG.

Therefore, when the hydroplane is detected only by the degree of change of the driven wheel speed sensor value as in the prior art, it can be detected only in the section A of FIG. In the case of the example, since the detection is made based on the difference between the control front wheel speed filter value and the front wheel speed sensor value, when the vehicle enters the hydroplane state, the hydraulic pressure is accurately detected over almost the entire area B from the entry to the exit. A plane state will be detected.

Further, for example, even when the front wheel speed sensor value is suddenly decelerated instantaneously due to road surface disturbance when driving on a rough road or the like,
As long as the difference from the control front wheel speed filter value from which the high frequency component has been cut does not exceed the set value V0, the hydroplane state is not detected.

Since the control front wheel speed filter value is created by setting an upper limit value for the change amount on the acceleration side and the deceleration side, if the control front wheel speed filter value is an acceleration change amount exceeding the upper limit value, When the control front wheel speed filter value is on the acceleration side upper limit value and the control front wheel speed filter value is a deceleration change amount exceeding the upper limit value, the control front wheel speed filter value deceleration side upper limit value is effective. That is, for example, when the front wheel speed sensor value changes from deceleration to acceleration as shown in FIG. 7, the front wheel speed sensor value and the control front wheel speed filter value do not greatly separate. The followability of both values becomes good, and when this control front wheel speed filter value is used for determining the acceleration / deceleration slip state, the acceleration / deceleration slip state is properly evaluated without being overestimated or underestimated, In addition, hydroplane Pseudo acceleration slip in also, as shown in FIG. 8, when the control of the front wheel speed sensor value,
While it is evaluated as an excessive acceleration slip amount S1, it is evaluated as a small acceleration slip amount S2.

FIG. 9 is a flowchart showing the flow of the control operation corresponding to the hydroplane performed by the TCS / ABS-ECU. Each step will be described below.

At step 60, the high pre-flag HYP
It is determined whether F is HYPF = 1.

If YES is determined in step 60,
The program proceeds to a step 61, wherein the engine output TE is controlled so as to maintain the vehicle speed VFTF at that time. This engine output control is performed by controlling the opening of the second throttle valve 21.

The vehicle speed VFTF is obtained by calculating an average value of the control right front wheel speed filter value VFTFR and the control left front wheel speed filter value VFTFL (corresponding to a vehicle speed detecting means).

For example, TE = α × VFTF ² + β (α × VFT
The engine output TE is controlled such that F ² ; the air resistance proportional to the square of the vehicle speed, β: the rolling resistance), and the vehicle speed VFTF is kept constant.

In step 62, it is determined whether or not the vehicle is in an acceleration slip state based on a difference between the rear wheel speed filter value and the front wheel speed filter value for control (corresponding to acceleration slip detection means).

When YES is determined in the step 62,
Proceeding to step 63, brake control is performed with a brake control gain at which the pressure increase / decrease speed has been reduced from the normal level (corresponding to a hydroplane corresponding control means).

On the other hand, if NO is determined in the step 60, the process proceeds to a step 64, in which the recover high pre-flag RH is set.
It is determined whether YF is RHYF = 0.

When it is determined YES at step 60,
Proceeding to step 65, it is determined whether or not the high pre-flag HYPF has just changed from 1 to 0. If YES, the process proceeds to step 66, where the recover high pre-flag RH
YF is set to RHYF = 1.

If RHYF = 1 is set in step 66, and if NO is determined in step 64, step 6 is executed.
The program proceeds to step 7, where the filter effect is lowered to obtain a control front wheel speed filter value, and traction control using both throttle and brake is performed.

At step 68, it is determined whether or not the vehicle is in the non-acceleration slip state. If the determination is YES, the routine proceeds to step 69, where the recovery high pre-flag RHYF is set to RH.
Cleared to YF = 0.

At step 69, RHYF = 1 is set, and when YES is determined at step 64, and when NO is determined at step 65, the process proceeds to step 70, where the control front wheel speed filter value is set by the normal filter effect. Then, the traction control is performed by using both the throttle and the brake.

The control action corresponding to the hydroplane will be described.

When entering the hydroplane state, the flow proceeds to step 60 → step 61 → step 62 → step 63, and the throttle control side maintains the vehicle speed VFTF at the time of the hydroplane entry regardless of the occurrence of acceleration slip. Throttle-dependent control is performed to adjust the engine output TE to
Under the condition that the acceleration slip occurs, the brake control with the low control gain is performed.

With the former throttle control, the vehicle speed VFTF at the time of entering the hydroplane state is maintained at both the high vehicle speed side and the low vehicle speed side in the hydroplane state. 2 throttle valve 21
Is set higher than the case based on the acceleration slip, and the second throttle valve 21 is set lower than the case based on the acceleration slip on the low vehicle speed side. Vehicle stability is ensured on the vehicle speed side.

In other words, in the prior art based on the acceleration slip, in the hydroplane state, the slip state of the driving wheels is overestimated due to the rapid decrease of the driven wheel speed, and the throttle control is performed regardless of the vehicle speed. On the vehicle speed side, the vehicle deceleration becomes large due to the throttle being too narrow, and on the low vehicle speed side, the slip cannot be suppressed due to the throttle being opened too much, which leads to deterioration of the vehicle stability.

According to the latter brake control, the vehicle is prevented from being locked when the accelerator is depressed to determine that the vehicle is in the hydroplane state and the vehicle is in an acceleration slip, thereby suppressing the acceleration slip of the driving wheels with good response. Stability is ensured.

That is, when the accelerator pedal is depressed in the hydroplane state, the drive wheels suddenly slip, as shown in FIG. 10, and brake control with good responsiveness is required. Also, at this time, when the brake control is performed by the normal control gain, the tire tends to grip due to the deceleration due to the water film resistance on the driven wheel (front wheel) side, and the driving wheel (rear wheel) side has excessive slip evaluation. As shown by the thick dotted line in FIG. 11, the rear wheels tend to lock due to the braking slip, and both the front and rear wheels lose tire grip. Therefore, as shown in FIG. 12, the brake control is performed with a lower control gain to suppress the brake pressure from becoming excessive, so that the driving wheel speed does not cause the braking slip as shown by the thin dotted line characteristic in FIG. It converges to the vehicle speed.

The hydroplane recovery control operation will be described.

When exiting the hydroplane state, step 60 → step 64 → step 65 → step 66
And the cover high pre-flag RHYF becomes RHYF =
At the next control cycle, the routine proceeds from step 64 to step 67, in which traction control is performed based on the control front wheel speed filter value due to the low filter effect. Is secured.

That is, when the traction control is performed based on the control front wheel speed filter value by the normal filter effect after the escape from the hydroplane state, the actual acceleration slip amount is S3 as shown in FIG. Nevertheless, the control driven wheel speed filter value indicated by the one-dot chain line does not readily return, and the acceleration slip amount is regarded as (S3 + S4). The excessive slip evaluation causes excessive acceleration slip control. On the other hand, as shown by the two-dot chain line characteristic in FIG. 13, the control front wheel speed filter value due to the low filter effect becomes a value close to the actual driven wheel speed, and the excessive slip evaluation is eliminated.

When the vehicle enters the non-acceleration slip state, RHYPF = 0 is cleared in step 69, and thereafter, step 60 → step 64 → step 65 → step 7
Then, the traction control is performed based on the control front wheel speed filter value based on the normal filter effect which is preferable for detecting the hydroplane state.

The effect will be described.

(1) When detecting the hydroplane state,
When the acceleration slip is detected by depressing the accelerator, the brake control is performed with a low control gain. Stability can be ensured.

(2) The vehicle speed VFTF is used as control information when the hydroplane state is detected, and the second throttle valve 2 is controlled so as to maintain the vehicle speed VFTF when the hydroplane state is detected.
Since the engine output TE is controlled by the opening degree of 1, the deceleration of the vehicle due to the throttle being excessively throttled can be suppressed when the vehicle is on the high vehicle speed side in the hydroplane state, and at the low vehicle speed side in the hydroplane state. At one time, deterioration of vehicle stability due to excessive opening of the throttle can be suppressed.

(3) The state of the hydroplane generated by the water film between the tire and the road surface during running is determined by the control front wheel speed filter value VFTFR (VFTFL) and the front wheel speed sensor value VWFR (VWF).
L) is calculated, and when the difference is equal to or greater than the set value V0, the apparatus detects the hydroplane state.
When entering the hydroplane state, the hydroplane state can be accurately detected over almost the entire area from the entry to the exit.

(4) A low-pass filter is applied to the front wheel speed sensor value VWFR (VWFL), and an upper limit value is provided for the change amount on the acceleration side and the deceleration side to control the front wheel speed filter value VWFR for control.
Because it is a device that creates FTFR (VFTFL), the front wheel speed sensor value VWFR (VWFL) and the control front wheel speed filter value VFTFR
(FFTFL), and the control front wheel speed filter value VFTFR (VFTFL) can be used to determine the acceleration / deceleration slip state.

(5) When the vehicle escapes from the hydroplane state, the traction control is performed based on the control front wheel speed filter value by the low filter effect until the vehicle enters the non-acceleration slip state. Acceleration can be ensured.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment.

For example, in the embodiment, an example of application to a traction control system using throttle and brake has been described. However, the present invention can also be applied to a system that performs traction control only by brake control.

[0084]

As described above, according to the present invention, in a traction control device for a vehicle which performs hydroplane countermeasure control at the time of detecting a hydroplane state, when the occurrence of acceleration slip is detected in the hydroplane state, Since the braking force of the drive wheels is controlled by a lower brake control gain, an effect is obtained that, when an acceleration slip occurs in the hydroplane state, vehicle stability can be ensured with good response.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing a traction control device for a vehicle according to the present invention.

FIG. 2 is an overall view of a braking / drive system control system for a rear wheel drive vehicle to which the vehicle traction control device of the embodiment is applied.

FIG. 3 is a hydraulic circuit diagram showing a brake fluid pressure control system of a braking / drive system control system to which the vehicle traction control device of the embodiment is applied.

FIG. 4 is a block diagram illustrating an outline of traction control in the embodiment.

FIG. 5 is a flowchart showing a flow of a hydroplane detection processing operation performed by an electronic control unit of the traction control system & anti-skid brake control system of the embodiment device.

FIG. 6 is a diagram showing a front wheel speed sensor value characteristic and a control front wheel speed filter value characteristic in the embodiment device.

FIG. 7 is a diagram showing a drive wheel speed characteristic, a front wheel speed sensor value characteristic, and a control front wheel speed filter value characteristic when shifting from deceleration to acceleration in the embodiment apparatus.

FIG. 8 is a graph showing wheel speed characteristics in a hydroplane state.

FIG. 9 is a flowchart showing a flow of a hydroplane-compatible control processing operation performed by the electronic control unit of the traction control system & anti-skid brake control system of the embodiment device.

FIG. 10 is a characteristic diagram of a vehicle speed, a drive wheel speed, and a driven wheel speed when an accelerator is depressed after entering the hydroplane.

FIG. 11 is a comparison characteristic diagram of drive wheel slip convergence with a normal control gain and a low control gain when brake control is performed after entering the hydroplane.

FIG. 12 is a brake pressure characteristic diagram in brake control with a normal control gain and a low control gain.

FIG. 13 is a graph showing wheel speed characteristics when an accelerator pedal is depressed after exiting the hydroplane state.

[Explanation of symbols]

 a driving wheel braking force control means b hydroplane detection means c acceleration slip detection means d hydroplane correspondence control means

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B60T 8/58-8/86 B60K 41/20 F02D 29/02 G01P 3/56

Claims (2)

(57) [Claims] 1. A driving wheel braking force control means for controlling a braking force of a driving wheel; a hydroplane detecting means for detecting a hydroplane state; an acceleration slip detecting means for detecting an acceleration slip condition of a driving wheel; A hydroplane corresponding control means for outputting a brake control command with a brake control gain lower than a brake control gain in normal traction control to the drive wheel braking force control means when an acceleration slip occurs in the drive wheels upon detection of a state. A traction control device for a vehicle, comprising: 2. A driving wheel braking force control means for controlling a driving force of a driving wheel; an engine output control means for controlling an engine output; a hydroplane detecting means for detecting a hydroplane state; Acceleration slip detection means for detecting the vehicle speed, a vehicle speed detection means for detecting the vehicle speed, and a control command for obtaining an engine output for substantially maintaining the vehicle speed at that time when the hydroplane state is detected is output to the engine output control means. Hydroplane corresponding control that outputs a brake control command to the drive wheel braking force control means with a brake control gain lower than the brake control gain in normal traction control when an acceleration slip occurs in the drive wheels upon detection of a plane state. And a vehicle traction control device.