JPH07106692B2 - Drive force controller for rear-wheel drive vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention controls engine output, wheel braking force, etc. when a drive wheel slip occurs at the time of starting, sudden acceleration, traveling on a low friction coefficient road, etc. The present invention relates to a drive force control device for a rear wheel drive vehicle that reduces drive force to drive wheels and suppresses drive wheel slip.

(Prior Art) Conventionally, as a vehicle engine output control device, for example, a device described in JP-A-60-43133 is known.

This conventional device includes drive wheel wheel speed detection means and driven wheel wheel speed detection means for detecting the wheel speeds of the drive wheel and the driven wheel as the detection means, and the drive wheel obtained based on the detection signal from the detection means. When the slip ratio exceeds a specified value, the fuel supply to the engine is forcibly reduced and the drive wheel slip ratio is controlled to reach the specified optimum value to improve starting performance and running stability on a low friction coefficient road. It was a device designed to improve performance.

(Problems to be Solved by the Invention) However, in such a conventional device, as described above, when the drive wheel slip ratio exceeds a predetermined value, the drive force to the drive wheels is uniquely increased. Since the configuration is such that the control is performed to decrease, it is possible to improve the starting performance and running stability performance on the low friction coefficient road accompanying the prevention of wheel spin, but at the time of acceleration turning on the high friction coefficient road, Even if you want to use sporty driving with power slide, which is a feature of wheel drive vehicles, the problem is that you cannot do sporty driving with power slide because the rotation of the rear wheels is suppressed due to the occurrence of drive wheel slip. was there.

For this reason, when the conventional driving force control device is installed in a rear-wheel drive vehicle for the purpose of sporty running, the features of this type of rear-wheel drive vehicle are lost and the commercialability is reduced. .

(Means for Solving Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and in order to achieve this object, the present invention provides the following solving means. did.

The solution means of the present invention will be described with reference to the claim correspondence diagram shown in FIG. 1. As the detection means 1, the drive wheel wheel speed detection means 101 and the driven wheel wheel speed detection means 102 for detecting the wheel speeds of the drive wheels and the driven wheels. When the drive wheel slip ratio obtained based on the detection signal from the detection means 1 exceeds a predetermined value, the drive force to the drive wheel is reduced, and the drive wheel slip ratio is controlled to an optimum value. In a rear wheel drive vehicle drive force control device including a drive force control means 3 for outputting a control signal to a drive force control actuator 2, the detecting means 1 detects lateral acceleration acting on a vehicle by calculation or measurement. If the lateral acceleration is greater than or equal to a predetermined value,
The means for prohibiting the driving force control for suppressing the driving wheel slip is used.

(Operation) In the rear wheel drive vehicle drive force control device of the present invention, by adopting the above-mentioned means, the drive wheels are automatically driven at the time of acceleration turn on a high friction coefficient road where the lateral acceleration is equal to or more than a predetermined value. The driving force control for suppressing slip is prohibited.

Therefore, when driving on a low friction coefficient road where lateral acceleration is small, driving force control can improve starting performance and running stability, and in addition, driving force control can be performed during acceleration turning on a high friction coefficient road. By prohibiting, it is possible to carry out sporty driving using the power slide, which is a feature of rear-wheel drive vehicles.

(Examples) Hereinafter, examples of the present invention will be described in detail with reference to the drawings. Incidentally, in describing this embodiment, a drive force control device for a rear wheel drive vehicle in which engine output control and brake control are used together to perform drive force control will be taken as an example.

First, the configuration of the embodiment will be described.

As shown in FIG. 2, a vehicle to which the driving force control device A of the embodiment is applied has a rear wheel drive system including an engine 10, a transmission 11, a propeller shaft 12, a differential 13, a left wheel side drive shaft 14, and a right wheel side. The drive shaft 15, the left rear wheel 16, the right rear wheel 17 are provided, and the left front wheel 18 and the right front wheel 19 are provided as driven wheels.

The driving force control apparatus A of the embodiment basically uses the wheel speeds Wf ₁ and Wf ₂ of the left and right front wheels 18 and 19 which are driven wheels and the wheel speeds Wr ₁ and Wr ₂ of the rear wheels 16 and 17 which are driving wheels. The slip ratios S ₁ and S ₂ are calculated, and when the slip ratios S ₁ and S ₂ exceed the set slip ratio S ₀ , the driving force of the left and right rear wheels 16 and 17 or one of the slipping rear wheels is reduced. It is a device for controlling.

Structurally, the left front wheel speed sensor 20, as an input sensor,
A left rear wheel speed sensor 21, a right front wheel speed sensor 22, a right rear wheel speed sensor 23 are provided, a driving force control unit 30 is provided as traction control means, and a left rear wheel braking valve actuator 40 is provided as a driving force control actuator. , A rear right wheel braking valve actuator 41 and a throttle adjusting actuator 42.

Each of the wheel speed sensors 20, 21, 22, 23 is composed of a rotor that rotates in synchronization with the wheel, and an electromagnetic pickup that generates an electromagnetic induction electromotive force in a coil due to the rotation of the rotor. , 21,22,23 from each wheel speed Wf ₁ , Wr
_1, Wf _2, wheel speed signal corresponding to _{Wr 2 (vf 1), (} vr 1), (v
f ₂ ) and (vr ₂ ) are output.

Here, the left front wheel speed sensor 20 and the left rear wheel speed sensor
Reference numeral 21 is used as a sensor for obtaining the left wheel side slip ratio S _1, and includes a right front wheel wheel speed sensor 22 and a right rear wheel wheel speed sensor 23.
Is used as a sensor for obtaining the right wheel side slip ratio S ₂ . The left front wheel speed sensor 20 and the right front wheel speed sensor 22 are used as sensors for obtaining the lateral acceleration Yg.

As shown in FIG. 3, the driving force control unit 30 is composed of an electronic control circuit centered on a microcomputer.

The internal circuit includes an input interface circuit 31, a memory 32, a CPU 33, and an output interface circuit 34.

The left rear wheel braking valve actuator 40 and the right rear wheel braking valve actuator 41 are, as shown in FIG.
A left rear wheel side brake pipe 53 and a right rear wheel side brake pipe 54 that connect the hydraulic power source 50 such as a hydraulic pump and a reservoir to the left rear wheel braking device 51 and the right rear wheel braking device 52.
Each valve actuator 40, 41 is provided in the middle of the above, and each valve actuator 40, 41 includes a switching valve section 40a, 41a and a valve solenoid 40b, 41b.

In addition, from the driving force control unit 30 to the valve solenoid 40
When the solenoid actuation signals (e ₁ ) and (e ₂ ) are output to b and 41b, the valve is switched to the open side, and pressurized hydraulic oil from the hydraulic pressure source 50 is supplied to the brake devices 51 and 52. The braking force is applied to the left and right rear wheels 16 and 17.

The throttle adjusting actuator 42 is an actuator that is provided in the throttle valve linkage and changes the opening of the throttle valve of the engine 10, and includes a valve operating mechanism section 42a and a valve solenoid 42b.

In addition, from the driving force control unit 30 to the valve solenoid 42
When the solenoid actuation signal (e ₃ ) is output to b, the valve opening of the throttle valve becomes small and the output of the engine 10 decreases.

Next, the operation of the embodiment will be described.

First, the flow of the driving force control operation in the driving force control device A of the embodiment will be described with reference to the flow chart shown in FIG.

In step 200, the wheel speeds Wf ₁ , Wr ₁ , Wf ₂ , Wr ₂ are read by the signals from the wheel speed sensors 20, 21, 22, 23.

In step 201, the drive wheel slip ratios S ₁ and S ₂ are calculated by the wheel speed information read in step 200.

The calculation formula of the drive wheel slip ratios S ₁ and S ₂ is Is.

In step 202, it is judged whether or not the drive wheel slip ratios S ₁ and S ₂ obtained in step 201 exceed the set slip ratio S ₀ .

If S ₁ > S ₀ or S ₂ > S ₀ , the next step 203
Then, when S ₁ ≦ S ₀ and S ₂ ≦ S ₀ , the driving force control is not performed.

In step 203, the lateral acceleration Yg is calculated by the left and right front wheel rotation speeds Wf ₁ and Wf ₂ read in step 200.

The calculation formula of the lateral acceleration Yg is as follows when the turning radius R, the vehicle speed V, and the yaw rate are set.

_{V = {(Wf 1 + Wf} 2) / 2} / r = K1 · | Wf 1 -Wf 2 | R = V / = K2 | (Wf 1 + Wf 2) / (Wf 1 -Wf 2) | Yg = V 2 _{/ R = K3 | (Wf 1} + Wf 2) * (Wf 1 -Wf 2) | where, K1, K2, K3 is a proportionality constant determined by vehicle specifications, r is a tire radius.

In step 204, the magnitude of the lateral acceleration Yg obtained in step 203 and the preset lateral acceleration Yg ₀ are compared, and when Yg <Yg ₀ , the step is an output step of driving force control. The routine proceeds to 205, and when Yg ≧ Yg ₀ , the driving force control is not performed.

When running on the power slide, the lateral acceleration Yg is generally 0.
Since 6G or more is generated, set lateral acceleration Yg ₀ to a value of about 0.6G.

In step 205, the driving force control for suppressing the wheel spin of the driving wheels is performed by the engine output control and the brake control.

When only one of the left and right rear wheels 16, 17 has a slip ratio that exceeds the set slip ratio S ₀ , the braking force is applied only to the side causing wheel spin.

As described above, the driving force control device A of the embodiment has the following effects.

In addition to the driving wheel slip ratio S, the lateral acceleration Yg is added to the driving force control start condition, and the driving wheel slip is automatically suppressed during an acceleration turn on a high friction coefficient road where the lateral acceleration Yg is equal to or greater than the set lateral acceleration Yg _0. Since it is a device that prohibits the driving force control for driving, when driving on a low friction coefficient road where the lateral acceleration Yg is small, it is possible to improve the starting performance and running stability performance by driving force control. When accelerating on a high friction coefficient road, prohibiting the driving force control allows sporty driving using the power slide, which is a feature of rear-wheel drive vehicles.

A wheel speed sensor is provided for each of the left and right wheels, and the left rear wheel 16
The slip ratio S _{1 of the} right rear wheel 17 and the slip ratio S ₂ of the right rear wheel 17 are calculated, and the driving force control of the left rear wheel 16 and the driving force control of the right rear wheel 17 are independently performed by braking. The slip state can be prevented.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention can be applied even if there is a design change or the like within a range not departing from the gist of the present invention. included.

For example, although the example in which the lateral acceleration Yg is calculated is shown in the embodiment, the actual lateral acceleration may be directly measured by the sensor and the measured value may be used for the control.

Further, in the embodiment, the example in which the left and right rear wheels are independently controlled has been shown, but a rear wheel rotation speed sensor is provided at the propeller shaft position to integrally control the left and right rear wheels. Good.

Further, in the embodiment, the example in which the braking actuator and the throttle adjusting actuator are used together is shown. However, only one of them may be used, and the driving force control actuator may be a gear position changing actuator of a transmission or The fuel injection amount control actuator of the engine or the like is not limited to the embodiment as long as the driving force transmitted from the wheels to the road surface can be reduced.

Further, the wheel speed sensor may be shared with the sensor used in the anti-skid device.

(Effects of the Invention) As described above, in the driving force control device for a rear wheel drive vehicle of the present invention, when the vehicle is accelerated and turned on a high friction coefficient road in which the lateral acceleration is a predetermined value or more, Since the device that prohibits the driving force control to suppress the driving wheel slip is used, the starting performance and the running stability performance are improved on the low friction coefficient road where the lateral acceleration is small, and the acceleration turning on the high friction coefficient road is performed. It is possible to obtain the effect that it is possible to achieve both power slide traveling at the same time.

[Brief description of drawings]

FIG. 1 is a diagram showing a driving force control device for a rear wheel drive vehicle according to the present invention, FIG. 2 is an overall view showing a rear wheel drive vehicle and a driving force control device for an embodiment, and FIG. 3 is an embodiment device. FIG. 4 is a block diagram showing the control system of FIG. 4, and FIG. 4 is a flow chart showing the flow of the driving force control operation of the embodiment apparatus. DESCRIPTION OF SYMBOLS 1 ... Detecting means 101 ... Driving wheel wheel speed detecting means 102 ... Driven wheel wheel speed detecting means 103 ... Lateral acceleration detecting means 2 ... Driving force control actuator 3 ... Driving force controlling means

Claims (1)

[Claims] 1. A driving wheel, which includes driving wheel wheel speed detecting means and driven wheel wheel speed detecting means for detecting wheel speeds of a driving wheel and a driven wheel, as the detecting means, and is obtained based on a detection signal from the detecting means. When the slip ratio exceeds a predetermined value, the driving force to the driving wheels is reduced, and the driving force control means for outputting a control signal for controlling the driving wheel slip ratio to the optimum value is provided to the driving force control actuator. In the driving force control device for a rear-wheel drive vehicle, a lateral acceleration detecting means for detecting a lateral acceleration acting on the vehicle by calculation or measurement is provided as the detecting means, and the driving force controlling means is provided with a lateral acceleration of a predetermined value or more. In this case, the driving force control device for a rear-wheel drive vehicle is characterized in that the driving force control for suppressing the driving wheel slip is prohibited.