Steering device for vehicle

• US 20010027893A1
• Filed: 01/17/2001
• Published: 10/11/2001
• Est. Priority Date: 02/08/2000
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.), Koyo Seiko Co., Ltd. (Toyota Motor Corporation)
• Original Assignee: KOYO Seiko Company Limited Sumitomo Brake Systems Incorporated
• Inventors: Nakano, Shiro, Segawa, Masaya, Takamatsu, Takanobu, Nishizaki, Katsutoshi
• Granted Patent: US 6,415,212 B2
• Time in Patent Office: Days
• US Class Current: 180/409
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B62D 6/00 Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00

Abstract

In a steering device for a vehicle, the movement of a steering actuator driven by operation of an operating member is transmitted to vehicle wheels, in such a manner that the steering angle changes, without the operating member being coupled mechanically to the vehicle wheels. A first target yaw rate is calculated in accordance with the detected vehicle speed and a first steering angle set value, which corresponds to the detected amount of operation and vehicle speed. A second target yaw rate corresponding to the detected lateral acceleration and vehicle speed is calculated. A second steering angle set value, which corresponds to the difference between the detected yaw rate and a target yaw rate, as which the first target yaw rate or the second target yaw rate whichever has the smaller absolute value is taken, is calculated. The steering angle actuator is controlled in such a manner that the steering angle corresponds to the target steering angle, that is the sum of the first steering angle set value and the second steering angle set value.

Claims

1. A steering device for a vehicle comprising:

an operating member;

a steering actuator driven by operation of the operating member;

means for transmitting the movement of the steering actuator to the vehicle wheels, in such a manner that the steering angle changes in accordance with the movement of the steering actuator, without the operating member being coupled mechanically to the vehicle wheels;

means for detecting the amount of operation of the operating member;

means for detecting the vehicle speed;

means for detecting the lateral acceleration of the vehicle;

means for detecting the yaw rate of the vehicle;

means for calculating a first steering angle set value corresponding to the detected amount of operation and vehicle speed, on the basis of a stored relationship between the amount of operation, the vehicle speed, and the first steering angle set value;

means for calculating a first target yaw rate corresponding to the calculated first steering angle set value and the detected vehicle speed, on the basis of a stored relationship between the first steering angle set value, the vehicle speed, and the first target yaw rate;

means for calculating a second target yaw rate corresponding to the detected lateral acceleration and vehicle speed, on the basis of a stored relationship between the lateral acceleration, the vehicle speed, and the second target yaw rate;

means for comparing the absolute value of the calculated first target yaw rate with the absolute value of the second target yaw rate;

means for calculating a second steering angle set value corresponding to the difference between the detected yaw rate and a target yaw rate, as which the first target yaw rate or the second target yaw rate whichever has the smaller absolute value is taken, on the basis of a stored relationship between the difference and the second steering angle set value; and

means for controlling said steering actuator in such a manner that said steering angle corresponds to a target steering angle, that is the sum of the calculated first steering angle set value and second steering angle set value.

2. The steering device for a vehicle according to

claim 1

, further comprising means for controlling at least one of the braking force of the vehicle wheels and the driving force of the vehicle wheels, so as to eliminate the difference between the detected yaw rate and the target yaw rate, as which the first target yaw rate or the second target yaw rate whichever has the smaller absolute value is taken.

3. The steering device for a vehicle according to

claim 1

, further comprising means for controlling the output of the engine generating driving force for the vehicle, so as to eliminate the difference between the first target yaw rate and the detected yaw rate.

4. The steering device for a vehicle according to

claim 2

, further comprising means for controlling the output of the engine generating driving force for the vehicle, so as to eliminate the difference between the first target yaw rate and the detected yaw rate.