JP2853425B2 - Traction control device for vehicles - Google Patents

Abstract

PURPOSE:To prevent the induction of acceleration slip effectively by providing a throttle control gain determining means which changes a throttle control gain so that the second throttle valve opening degree may become smaller at the time of shifting up an automatic transmission compared with a usual control gain. CONSTITUTION:There are provided the first throttle opening degree detecting means (h) which detects the first, throttle opening decree of the first throttle valve (c), and the second throttle opening degree detecting means (i) which detects the second throttle opening degree of the second throttle valve (e). At the time of shifting up an automatic transmission, a throttle control gain determining means (j) changes a throttle control gain in an accelerating slip throttle control system (h) so that the more the deflection between the first throttle opening degree and the second throttle opening degree becomes, the more the second throttle valve opening degree may become smaller compared with a usual control gain. It is thus possible to prevent the induction of acceleration slip effectively without changing control over the automatic transmission side.

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 controls acceleration slip in a vehicle equipped with an automatic transmission by performing throttle control on a second throttle valve in tandem with a first throttle valve.

[0002]

2. Description of the Related Art Conventionally, a traction control device for a vehicle in which acceleration slip is suppressed by throttle control of a second throttle valve arranged in tandem with a first throttle valve is described in, for example, JP-A-61-85248. Known devices are known.

[0003]

However, when the traction control device for a vehicle is applied to a vehicle equipped with an automatic transmission and the upshift is performed during the traction control, the first throttle opening> the second throttle opening. The automatic transmission side overestimates the engine torque based on the first throttle opening from the actual engine torque determined by the second throttle opening from the relationship between the degrees, so that the line pressure is set to a relatively large value. An abrupt change in torque due to the increase causes an acceleration slip, which reduces vehicle stability.

That is, the line pressure of the automatic transmission is estimated based on the accelerator opening (first throttle opening), and is optimally controlled to match the estimated engine torque. On the other hand, as shown in FIG. 8, during the TCS throttle control, the engine torque should be estimated at the second throttle opening θ ₂ to obtain the line pressure P ₂ , but actually, the first throttle opening θ ₁ in the engine torque is set to be estimated line pressure P _1. Therefore, the line pressure may be set by the select low of both throttle openings θ ₁ and θ ₂ , but the shift position is determined by the second throttle opening θ ₂ by the shift control based on the shift schedule. If this is done, during the TCS throttle control, shift hunting will occur as the value of the second throttle θ ₂ fluctuates greatly, and the input to the A / T control unit will be applied only to vehicles equipped with a traction control device. It is disadvantageous in terms of cost to increase the number.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is directed to a traction control device for a vehicle in which acceleration slip is suppressed by throttle control of a second throttle valve in a tandem arrangement in a vehicle equipped with an automatic transmission. It is another object of the present invention to effectively prevent the induction of the acceleration slip without changing the control of the automatic transmission at the time of shifting up during the acceleration slip control.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, in a vehicle traction control device according to the present invention, when an automatic transmission shifts up, the larger the deviation between the first throttle opening and the second throttle opening, the more the vehicle accelerates. A means for changing the throttle control gain in the slip throttle control system to a direction in which the second throttle valve opening is narrowed more than the normal control gain.

That is, as shown in the claim correspondence diagram of FIG. 1, the accelerator pedal b is disposed in the engine intake passage a.
, A second throttle valve e arranged in series with the first throttle valve c in the engine intake passage a and operated by an actuator d, and a first throttle valve c An automatic transmission control system f that determines a shift position of the automatic transmission according to the throttle opening and outputs a shift-up signal, and a second throttle valve e that suppresses acceleration slip according to the occurrence of acceleration slip. (2) an acceleration slip throttle control system g for controlling the throttle opening in the closing direction, first throttle opening detecting means h for detecting the first throttle opening of the first throttle valve c, and a second throttle valve e for controlling the second throttle valve e. A second throttle opening detecting means i for detecting a second throttle opening; Throttle control gain determining means for changing the throttle control gain in the acceleration slip throttle control system h in a direction in which the second throttle valve opening is more narrowed as compared with a normal control gain as the deviation between the throttle opening and the second throttle opening increases. j.

[0008]

When an acceleration slip occurs, the acceleration throttle control system g controls the second throttle opening of the second throttle valve e in the closing direction in order to suppress the acceleration slip in accordance with the occurrence of the acceleration slip. In addition, when the automatic transmission is upshifted, the throttle control gain determining means j determines whether the first throttle opening degree detecting means h is in use.
As the deviation between the first throttle opening from the second throttle opening and the second throttle opening from the second throttle opening detecting means i increases, the throttle control gain in the acceleration slip throttle control system h becomes smaller than the normal control gain. The degree of opening is changed to a smaller value. Therefore, when the automatic transmission is shifted up during the acceleration slip throttle control, the acceleration slip throttle control is performed by the throttle control gain changed in the direction to further narrow the opening of the second throttle valve, and the reduction amount of the engine torque is reduced. It will be great.

On the other hand, on the automatic transmission side, the line pressure is set to be relatively large by overestimating the engine torque based on the first throttle opening, and the torque changes abruptly with upshifting. It is proportional to the deviation between the throttle opening and the second throttle opening. However, this torque change width is suppressed to a small value by reducing the engine output from the normal by changing the control gain, and the induction of the acceleration slip is effectively prevented.

[0010]

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 throttle control side is equivalent to an acceleration slip throttle control system) that uses brake control to apply braking force is also installed, and front and rear wheel brake hydraulic pressure control to prevent wheel lock during deceleration slip It is equipped with an anti-skid brake control system. The centralized electronic control of these systems is based on the traction control system & anti-skid brake control system electronic control unit TCS / ABS-ECU (hereinafter referred to as TCS / ABS-ECU).
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) Number signal, a first throttle signal TVO1 from a first throttle sensor 16 (corresponding to first throttle opening detecting means), and a second throttle signal from a second throttle sensor 17 (corresponding to second throttle opening detecting means). The signal TVO2 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). . Of the traction control, the throttle control side is called TCS throttle control, and the brake control side is called TCS brake control.

Further, the TCS / ABS-ECU detects a deceleration slip, and outputs a solenoid signal as a brake pressure increasing / decreasing signal to each solenoid valve of the TCS / ABS-HU. This anti-skid brake control is called ABS 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 driving circuit. The TCM receives a first throttle signal TVO1 from a first throttle sensor 16 and outputs it to a TCS / ABS-ECU as a 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 provided with a throttle motor 18 (actuator). ).

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.

Further, as shown in the figure, an automatic transmission control system (corresponding to an automatic transmission control system) having an A / TC / U and a shift solenoid and performing shift control, lock-up control, etc. is mounted as shown in the figure. The gear position signal and the shift-up signal are taken into the TCS / ABS-ECU from the A / TC / U.

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 TCS brake control and ABS 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 ABS brake control, the two switching valves 35a and 35b are turned off as shown in the figure to introduce the hydraulic pressure from the master cylinder 30.
During the TCS brake control, both switching valves 35a and 35b are turned on to introduce the hydraulic pressure from the second accumulator unit AU2. For example, in the pressure increase mode in the TCS brake control, both control valves 36c, 36d, 37c, and 37d are connected as shown in the figure.
It is set to the OFF position.
In the pressure reduction mode, both control valves 36c, 36d, 37c, 37d are set to the ON position, and the brake fluid from the wheel cylinders 33, 34 is stored in the rear wheel side reservoir 38b. The rotation of the rear wheel side pump 39b returns to the rear wheel side damper chamber 40b.

The first accumulator unit AU1 is used as a hydraulic pressure source for the hydraulic booster 28, and the second accumulator unit AU2 is used as a hydraulic pressure source for TCS brake control. A predetermined accumulator pressure is maintained by the common pump unit PU that sucks in.

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 classified 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 The signal of the lateral acceleration sensor 5 is subjected to a filtering process, and a turning / straight traveling judgment based on the lateral acceleration and a target slip state suitable for the running state are calculated based on the vehicle speed.

(3) TCS brake control The actual brake state is compared with the target slip state to calculate the required brake increasing / decreasing speed (control duty ratio) and output it to the TCS / ABS-HU.

(4) TCS Throttle Control The 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.

Further, in order to secure 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 responsive engine torque increase / decrease control, optimal throttle control according to the engine speed is performed.

(B) Shift-up traction control operation FIG. 5 is a flowchart showing the flow of shift-up traction control processing performed by the TCS / ABS-ECU.
Hereinafter, each step will be described.

In step 50, wheel speed sensors 1, 2, 2,
Filter processing is performed on the signals 3 and 4, and the actual slip state (slip amount, slip amount difference value) is calculated based on the wheel speed values after the filter processing.

In step 51, it is determined whether or not an acceleration slip has occurred by comparing the actual slip state with the target slip state.

In step 52, it is determined whether or not the vehicle is in the upshift state based on the upshift signal from A / TC / U.

In step 53, when it is determined in step 52 that the vehicle is not in the upshift state, the control gain and T of the normal TCS throttle control for performing the control described in (a) above.
The control gain of CS brake control is determined.

[0042] In step 54, when it is determined that the upshift condition in the step 52, in response to the first throttle opening theta ₁ size and the throttle opening deviation (θ ₁ -θ ₂₎ T
The control gain of CS throttle control and the control gain of TCS brake control are determined (corresponding to throttle control gain determining means).

As shown in FIG. 6, the control gain of the TCS throttle control is such that the larger the first throttle opening θ _{1 and the} larger the throttle opening deviation (θ ₁ −θ ₂ ), the smaller the throttle closing opening. Thus, the control gain is changed. It should be noted that a small throttle opening means that the absolute value of the opening is reduced so as to reduce the engine output. Further, the control gain of the TCS brake control, as shown in FIG. 7, that the first throttle opening theta ₁ is to increase the throttle opening difference (θ ₁ -θ ₂₎ the larger the larger the braking increase, pressure reduction rate Changes the control gain.

In step 55, TCS throttle control and TCS brake control are performed based on the control gain determined in step 53 or step 54.

(C) TCS control + non-shift up When TCS control due to the occurrence of acceleration slip is in a non-shift up state, the flow proceeds to step 50 → step 51 → step 52 → step 53 → step 55, and The normal traction control described in a) is performed.

(D) TCS control + shift up When the TCS control due to the occurrence of acceleration slip is in the upshift state, step 50 → step 51 → step 5
2 → Step 54 → Step 55
In step 54, the throttle-closed than normal throttle-closed as the first throttle opening theta ₁ is greater throttle opening difference (θ ₁ -θ ₂₎ is large is small, the first
Throttle opening theta ₁ is greater throttle opening deviation (theta ₁
The larger the -θ ₂ ), the larger the brake increase / decrease speed is than the normal brake increase / decrease speed.

Therefore, when the automatic transmission is shifted up during the TCS control, the TCS is changed by the throttle control gain changed in the direction in which the second throttle valve 21 is further throttled.
By performing the throttle control and performing the TCS brake control with the brake control gain changed in the direction of increasing the brake pressure applied to the left and right rear wheels, the amount of reduction in traction acting on the left and right rear wheels is larger than usual. Become.

On the other hand, although the relationship of θ ₁ > θ _{2 is established} by the TCS control, the line pressure is set to be relatively large on the automatic transmission side because the engine torque is overestimated by the first throttle opening θ _1. The torque changes rapidly with the upshift.

However, this torque change width is suppressed to a small value by the control gain change control in which the acceleration slip suppression margin is increased as compared with the normal case, and the induction of the acceleration slip at the time of upshift is effectively prevented.

The effect will be described.

(1) A traction control device for a vehicle which performs acceleration control in a vehicle equipped with an automatic transmission by performing throttle control on a second throttle valve 21 disposed in tandem with the first throttle valve 19.
When the automatic transmission shifts up, the first throttle opening θ ₁
And the second throttle opening θ ₂ (θ ₁
-Θ ₂ ), the larger the value of −θ ₂ ), the more the throttle opening in the TCS throttle control is changed in the direction in which the second throttle valve opening is more narrowed compared to the normal throttle opening. At the time of raising, the induction of acceleration slip can be effectively prevented by changing the control gain on the traction control side without changing the control on the automatic transmission side.

(2) The present invention is applied to a traction control device for a vehicle that performs suppression of acceleration slip by using both TCS throttle control and TCS brake control. When shifting up during acceleration slip control, both brake control gain and throttle control gain are used. Since the change is made at the same time, the amount of improvement in the effect of suppressing the acceleration slip is increased as compared with the case where only the TCS throttle control is performed, and the prevention of the induction of the acceleration slip can be systematically achieved at a high level.

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 is shown in which the acceleration slip is applied to the traction control device for a vehicle in which both the TCS throttle control and the TCS brake control are performed, but the acceleration slip is suppressed only by the TCS throttle control. The present invention can also be applied to a traction control device for a vehicle.

[0055]

As described above, according to the present invention, there is provided a traction control device for a vehicle, in which a vehicle equipped with an automatic transmission controls acceleration slip by performing throttle control on a second throttle valve in a tandem arrangement. The first throttle opening and the second
The larger the deviation of the throttle opening, the more the means for changing the throttle control gain in the acceleration slip throttle control system to a direction in which the second throttle valve opening is narrowed more than the normal control gain. At the time of the up, the effect that the induction of the acceleration slip can be effectively prevented without changing the control of the automatic transmission side is obtained.

[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 brake pressure difference corresponding control processing operation performed by a TCS & ABS electronic control unit of the embodiment device.

FIG. 6 is a characteristic diagram of a throttle opening degree (throttle control gain) with respect to a first throttle opening degree and a throttle opening degree deviation.

FIG. 7 is a characteristic diagram of a brake increasing / decreasing speed (brake control gain) with respect to a first throttle opening and a throttle opening deviation.

FIG. 8 is a line pressure characteristic diagram at a first throttle opening and a second throttle opening.

[Explanation of symbols]

 a engine intake passage b accelerator pedal c first throttle valve d actuator e second throttle valve f automatic transmission control system g acceleration slip throttle control system h first throttle opening detection means i second throttle opening detection means j throttle control gain Decision means

Claims (1)

(57) [Claims] A first throttle valve arranged in an engine intake passage and operated in conjunction with an accelerator pedal; a second throttle valve arranged in series with the first throttle valve in the engine intake passage and operated by an actuator; An automatic transmission control system for determining a shift position of the automatic transmission according to a first throttle opening degree of a first throttle valve and outputting a shift-up signal; An acceleration slip throttle control system for controlling a second throttle opening of the second throttle valve in a closing direction, a first throttle opening detecting means for detecting a first throttle opening of the first throttle valve, and a second throttle A second throttle opening detecting means for detecting a second throttle opening of the valve; At the time of shifting up the dynamic transmission, as the deviation between the first throttle opening and the second throttle opening increases, the throttle control gain of the acceleration slip throttle control system is reduced more than the normal control gain. A traction control device for a vehicle, comprising: a throttle control gain determining means for changing a direction.