JPH02151556A - Turning motion control device for vehicle - Google Patents

Abstract

PURPOSE:To enable a turning motion to be automatically corrected of a vehicle by calculating a reference value of a physical amount, generated in the turning motion of the vehicle, and controlling to apply a brake either right or left wheel in accordance with a deviation of this reference value from the detected actual physical amount. CONSTITUTION:In the case of a vehicle supplying a brake fluid pressure from a master cylinder MC through right and left brake pressure control means 4L, 4R to each brake BL, BR provided in right and left rolling wheels WFR, WFL and right and left drive wheels WMR, WML, a yaw rate detecting means 2, detecting a yaw rate as a physical amount generated in the time of a vehicle turning, and a reference yaw rate arithmetic means 7 are provided. And the deviation of a reference value of the yaw rate from the detected value is obtained in a deviation calculating means 9 controlling being based on the deviation a brake side selecting means 20 selectively controlling the right and left brakes BR, BL. The reference yaw rate arithmetic means 7 is provided to calculate the reference yaw rate to have to be at present based on a hysteresis of a steering angle and the reference yaw rate.

Description

DETAILED DESCRIPTION OF THE INVENTION A8 OBJECTS OF THE INVENTION (1) Industrial Field of Application The present invention relates to a turning motion control device for a vehicle in which independently controllable brakes are mounted on both front and rear left and right wheels.

(2) Prior Art Conventionally, in such vehicles, there is a well-known technology for increasing or decreasing the braking force when the traction control device is used to accelerate slippage, and when the brake lock is locked using the anti-lock brake control device.

(3) Problems to be Solved by the Invention However, for example, understeering and oversteering phenomena that occur when a vehicle is steered during cruise driving cannot be solved unless the driver corrects the steering himself. method has not been implemented.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a turning motion control device for a vehicle that can automatically correct the turning motion of the vehicle.

B0 Structure of the Invention (1) Means for Solving the Problem The present invention detects a steering angle in a turning motion control device for a vehicle in which independently controllable brakes are installed on both front and rear left and right wheels. a steering angle sensor,
a steering angle history accumulation means for accumulating a history of the steering angle; a turning motion reference value calculation means for determining a reference value of a physical quantity occurring during the vehicle turning motion based on the history of the steering angle; detection means for detecting the actual value of the physical quantity; deviation calculation means for determining the deviation between the reference value and the actual value of the object burial; and braking for selecting which of the left and right wheels to brake in accordance with the deviation. and a side selection means.

(2) Effect According to the above configuration, the reference value of the physical quantity that occurs during the turning motion of the vehicle is calculated, and one of the left and right wheels is selected based on the deviation between the actual value of the detected physical quantity and the reference value. The turning motion is automatically corrected.

(3) Example Hereinafter, an example of the present invention will be explained with reference to the drawings. First, in FIG. 1, left and right free rolling wheels WFL of a vehicle,
Speed sensors 1t, 1m are individually attached to W□, and these speed sensors It.

The wheel speeds V, , V□ detected at 1 m are input to a yaw rate detection means 2 and a vehicle speed detector 3, respectively, for detecting a yaw rate as a physical quantity that occurs when the vehicle turns. In addition, independently controllable brakes Bt and Bi are attached to the left and right driving wheels WM, , W□ and the left and right free rolling wheels W, L, W, 8, respectively, and these brakes Bt, Bi are attached from the mask cylinder MC. 'The brake hydraulic pressure supplied to the left brake pressure control means 4L and the right brake pressure control means 4L. Each is controlled by Furthermore, a steering angle sensor 6 for detecting a steering angle δ is attached to the steering handle 5.

The history of the steering angle δ detected by the steering angle sensor 6 and the vehicle speed Vv obtained by the vehicle speed detector 3 are input to a reference yaw rate calculation means 7 as a turning movement reference value calculation means. The reference yaw rate Yb obtained by the reference yaw rate calculating means 7 and the yaw rates Y and l obtained by the yaw rate detecting means 2 are respectively input to the deviation calculating means 9, and the deviation obtained by the deviation calculating means 9 is inputted to the deviation calculating means 9. Dr (=Y,
-Yb, , ), one of the left and right brakes BL, Bll is selectively controlled.

The yaw rate detection means 2 includes a wheel speed difference calculation circuit 11,
A yaw rate approximate value calculation circuit 12, a recursive low-pass filter 13, a history accumulation circuit 14 that accumulates the previous value Y l , -1 of the yaw rate approximate value Y'7 obtained by the yaw rate approximate value calculation circuit 12, and a recursive low-pass filter 13. The previous value Yn of the yaw rate actual value Y7 obtained by the type low-pass filter 13, .
, and a history accumulation circuit 15 that accumulates the value Y, -2 from the previous time.
Equipped with.

The wheel speed difference calculation circuit 11 is a speed sensor IL.

Difference ΔVw (=
In the yaw rate approximation calculation circuit 12, the yaw rate approximate value Y' (-dXΔVw) is obtained by multiplying the difference ΔVw by a constant proportionality constant d. Here, the proportionality constant d is the free rolling wheels W, L, W,
, I, for example d=1. The recursive low-pass filter 13 eliminates the influence of vibrations of the vehicle suspension on the wheel speeds V, , V. Here, the variation in wheel speed Vt, V* due to resonance with suspension vibration while driving on a rough road is approximately 10) 1 z, and the frequency range of the yaw rate used to control vehicle turning motion is 0 to 2 Hz. Therefore, the recursive low-pass filter 13 filters the approximate value Y' fi of the yaw rate with an attenuation range of 2 Hz or more.

That is, in the recursive low-pass filter 13, based on the signals from the yaw rate approximation value calculation circuit 12 and both history storage circuits 14 and 15, the calculation of the following equation (1) is performed, where the output value is Yn. .

Y,=α1・YI11+αZ'Y' n-1+β,
・Yll-5+β2・Yfi-,...(1) Here,
β1. β2. β1. β2 is a constant determined by experimental results. Furthermore, since the filtering calculation is repeated in a constant cycle, the subscripts .

The vehicle speed detector 3 outputs the vehicle speed Vv based on the wheel speeds VL, V detected by both speed sensors IL, IK. For example, the average value of the side wheel speeds VL, VR is the vehicle speed Vv. is output as Further, the steering angle δ obtained by the steering angle sensor 6 is inputted to the steering angle history storage means 16, and the previous value δm-1 and the values δ and -2 of the previous steering angle δ are accumulated in the steering angle history storage means 16. be done.

The reference yaw rate calculation means 7 includes a calculation parameter selection circuit 17, a calculation circuit 18 for calculating the reference yaw rate Ybfi, a previous value ybR- of the reference yaw rate Ybn obtained by the calculation circuit 18, and a previous value yb, t. A reference yaw rate history accumulation circuit 19 is provided.

The calculation parameter selection circuit 17 selects calculation parameters aI + az, b+, bz used in the calculation in the calculation circuit 18.
is selected according to the vehicle speed Vv obtained by the vehicle speed detector 3, and each calculation parameter a (, a
The value of z + b + + bz is input to the arithmetic circuit 18 .

The calculation circuit 18 calculates the current reference yaw rate Yb based on the steering angle δ history from the steering angle history storage means 16 and the reference yaw rate 1-Ybn history from the reference yaw rate history storage circuit 19. and the next (
2) An operation according to the formula is performed.

Yb, = a, -δ, , -, +a2-δn-1-b, ・Y
b,, -+ bz・Yb,, -2... (2) The deviation calculation means 9 calculates the actual yaw rate value Y and the reference yaw rate) Y
As shown in FIG. 3, in the understeering and oversteering states when the vehicle turns left and right, the deviation Dr has a minus sign and is calculated from the deviation calculation means 9. Output. Here, in FIG. 3, the actual yaw rate value Y1 is shown by a solid line,
The reference yaw rate Ybn is indicated by a broken line.

The deviation Dr outputted from the deviation calculation means 9 is sent to the left brake pressure control means 41 and the right brake pressure control means 4 through the braking side selection means 20. Connected to I.

The braking side selection means 20 includes a switch 21 having a common contact 21a connected to the deviation calculation means 9 and individual contacts 21b and 21c individually connected to the split pressure control means 4L and 4K; and a comparator 22 for changing the switching mode of 21. The comparator 22 is for determining whether the deviation Dr outputted from the deviation calculating means 9 is positive or negative, and when the sign of the deviation Dr is 10, the individual contact 21c connected to the right braking pressure control means 4m is connected to the common contact 21a. Furthermore, when the sign of the deviation Dr is -, the switching mode of the switch 21 is changed so that the individual contact 21b connected to the left braking pressure control means 4L is connected to the common contact 21a.

Further, both split dynamic pressure control means 4L and 4R are connected to the mask cylinder M.
On-off valves 23L, 23 and control valves 24L, 241, which are interposed in series between C and brakes Bt, Bm, and control amount setting means 25L, 2511 for controlling the operation of these valves 23L, 23+t 124L, 2411. Equipped with The control amount setting means 25L, 251 are set with a control amount corresponding to the deviation Dr input from the deviation calculation means 9, and open the on-off valves 23L, 231 when connected to the deviation calculation means Dr. At the same time, the control valve 24L supplies braking pressure according to the deviation Dr to the brakes BL, B.
, 241.

Such braking side selection means 20 and braking pressure control means 4t,
According to 4i, when the deviation Dr has a sign of 10 as shown in FIGS. 3(a) and 3(d), the right brake BL is activated to correct the steering angle toward the right turning side, and As shown in FIGS. 3(b) and 3(c), when the deviation Dr has a negative sign, the left brake B is activated to correct the steering angle toward the left turning side.

Next, to explain the operation of this embodiment, the deviation D' between the yaw rate Y7 obtained by the yaw rate detection means 2 and the reference yaw rate Yb obtained by the reference yaw rate calculation means 7 is calculated by the deviation calculation means 9, Based on the deviation Dr, one of the left and right brakes BLB11 is activated.

Therefore, the reference yaw rate Yb, which is the reference value of the physical quantity that occurs during the vehicle turning movement, is calculated, and the turning movement is corrected to approach the calculated value, and the turning movement is automatically corrected without the driver performing corrective steering. The pivoting motion will be corrected.

C0 Effects of the Invention As described above, the device according to the present invention includes a steering angle sensor that detects a steering angle, a steering angle history storage means that accumulates a history of the steering angle, and a steering angle sensor that detects a steering angle based on the history of the steering angle. A turning movement reference value calculating means for determining a reference value of a physical quantity occurring during a turning movement of a vehicle, a detecting means for detecting an actual value of the physical quantity during the turning movement of the vehicle, and a deviation between the reference value and the actual value of the physical quantity. Since it is equipped with a deviation calculation means and a braking side selection means that selects which of the left and right wheels should be braked according to the deviation, it is possible to calculate a reference value of a physical quantity that occurs during a vehicle turning motion, and also to detect the reference value and the braking side. The turning motion of the vehicle can be automatically corrected by braking either the left or right wheel according to the deviation from the actual physical quantity.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is an overall block diagram, Fig. 2 is a graph showing an example of the output characteristics of the calculation parameter selection circuit, and Fig. 3 is an understeering diagram when the vehicle turns left and right. and FIG. 7 is a diagram showing deviations depending on oversteering conditions. 2... Yaw rate detection means, 4L, 41... Braking pressure control means, 6... Steering angle sensor, 7... Reference yaw rate calculation means as turning movement reference value calculation means, 9...
- Deviation calculation means, 16...Steering angle history accumulation means, 20
...Brake side selection means, 25L, 25. ...Controlled amount setting means, Bt, B+t...Brake, W, L, W□+ WII
IL, W□...Wheel (Dr>0) (Dr<O) Fig. 2 Fig. 3 (Dr<0) (Dr>O)

Claims (3)

[Claims] (1) In a turning motion control device for a vehicle in which independently controllable brakes are installed on both the front and rear left and right wheels, a steering angle sensor that detects the steering angle and a history of the steering angle are accumulated. a steering angle history accumulation means; a turning motion reference value calculation means for determining a reference value of a physical quantity occurring during a turning motion of the vehicle based on the history of the steering angle; and a detection means for detecting an actual value of the physical quantity during the turning motion of the vehicle. a deviation calculation means for calculating a deviation between a reference value and an actual value of the physical quantity; and a braking side selection means for selecting which of the left and right wheels is to be braked according to the deviation. swivel motion control device. (2) The braking side selection means is configured to output a selection signal in accordance with the sign of the deviation (1).
) The turning motion control device for a vehicle according to item 1. (3) The turning motion control device for a vehicle according to item (1) or item (2), further comprising a control amount setting means for generating a brake pressure control signal according to the deviation.