EP0199347A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for controlling steer angle of rear wheels of vehicle
Assignee: Toyota Central R&D Labs Inc
•
Filing: 1986-04-23
•
Granted: —
•
Expires: 2006-04-23
Abstract
Abstract 0 A rear wheel steer angle controlling apparatus for vehicles having steerable front and rear wheels, adapted for controlling the steer angle of rear wheels in response to the operation of the steering wheel for steering the front wheels. The speed with which the steering wheel is turned is detected and compared with a reference value which varies in accordance with changes in a physical amount related to the vehicle velocity. When the speed of operation of the steering wheel is larger than the reference value, a rear wheel steer angle is formed in the counter direction to the direction of the front wheel steer angle, so that the response to the steering input for turning the vehicle is improved. Conversely, when the speed of operation of the steering wheel is smaller than the reference value, a rear wheel steer angle is formed in the same direction as the front wheel steer angle, thus enhancing the stability of the vehicle running straight.
Inventors
- 👤 Kazuo Miki
- 👤 Yasutaka Hayashi
- 👤 Katsuhiko Fukui
- 👤 Kazumasa Sumi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 20:27
CPC Classifications
B; B62; B62D; B62D7/00; B62D7/06; B62D7/14; B62D7/15; B62D7/159; B62D7/1554; B62D7/1572
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
256 words
A rear wheel steer angle controlling apparatus for automatically controlling a steer angle of rear wheels of a vehicle by controlling an actuator mechanism for generating the steer angle of the rear wheels in response to an operation of a steering wheel for generating a steer angle of front wheels of said vehicle, said apparatus comprising: a steering wheel displacement detecting means for detecting a steering wheel displacement and for generating a steering wheel displacement signal representing the steering wheel displacement; and a physical amount detecting means for detecting a physical amount related to a velocity of said vehicle and outputting a physical amount signal, characterized in that there is further provided a control means adapted to calculate a speed of operation of said steering wheel on the basis of said steering wheel displacement signal, set a reference value which varies in accordance with said physical amount signal, make a comparison between the speed of operation of said steering wheel and said reference value, and control said actuator mechanism in accordance with the result of the comparison such that: (a) when the speed of operation of said steering wheel is smaller than said reference value, the steer angle of said rear wheels is generated in the same direction as the steer angle of said front wheels; and (b) when the speed of operation of said steering wheel is larger than said reference value, the steer angle of said rear wheels is generated in the direction counter to a direction of steer angle of said front wheels.
Claim 2
Dependent Claim
256 words
A rear wheel steer angle controlling apparatus for automatically controlling a steer angle of rear wheels of a vehicle by controlling an actuator mechanism for generating the steer angle of the rear wheels in response to an operation of a steering wheel for generating a steer angle of front wheels of said vehicle, said apparatus comprising: a steering wheel displacement detecting means for detecting a steering wheel displacement and for generating a steering wheel displacement signal representing the steering wheel displacement; and a physical amount detecting means for detecting a physical amount related to a velocity of said vehicle and outputting a physical amount signal, characterized in that there is further provided a control means adapted to calculate a speed of operation of said steering wheel on the basis of said steering wheel displacement signal, set a reference value which varies in accordance with said physical amount signal, make a comparison between the speed of operation of said steering wheel and said reference value, and control said actuator mechanism in accordance with the result of the comparison such that: (a) when the speed of operation of said steering wheel is smaller than said reference value, the steer angle of said rear wheels is generated in the same direction as the steer angle of said front wheels; and (b) when the speed of operation of said steering wheel is larger than said reference value, the steer angle of said rear wheels is generated in the direction counter to a direction of steer angle of said front wheels.
Claim 3
Dependent Claim
151 words
A rear wheel steer angle controlling apparatus according to Claim 1, said control means further comprising means for controlling the amount of the movement of said actuator mechanism in response to the level of said steering wheel displacement signal, and controlling said actuator mechanism in accordance with the result of the comparison such that: (a) when the speed of operation of said steering wheel is smaller than said reference value, the steer angle of said rear wheels corresponding to the level of said steering wheel displacement signal is generated in the same direction as the steer angle of said front wheels; and (b) when the speed of operation of said steering wheel is larger than said reference value, the steer angle of said rear wheels corresponding to the level of said steering wheel displacement signal is generated in the direction counter to a direction of steer angle of said front wheels.
Claim 4
Dependent Claim
198 words
A rear wheel steer angle controlling apparatus according to Claim 1, wherein said control means comprises: a calculating means for calculating an angular frequency of said steering wheel corresponding to a speed of operation of said steering wheel on the basis of said steering wheel displacement signal; a setting means for setting a reference value which involves a very small value close to zero and continuously varies in accordance with changes in a physical amount related to said vehicle velocity; a judging means for making judgement as to whether said angular frequency is larger or smaller than said reference value by making a size comparison therebetween; and a processing means for controlling said actuator mechanism on the basis of the level of said steering wheel displacement signal and the result of judgement by said judging means such that: (a) when said angular frequency is smaller than said reference value, said steering wheel displacement signal is amplified by a predetermined amplification factor and output to said actuator mechanism; and (b) when said angular frequency is larger than said reference value, said steering wheel displacement signal is inversely amplified by a predetermined amplification factor and output to said actuator mechanism.
Claim 5
Dependent Claim
241 words
A rear wheel steer angle controlling apparatus according to Claim 1, wherein said control means comprises: a calculating means for calculating an angular frequency of said steering wheel corresponding to a speed of operation of said steering wheel on the basis of said steering wheel displacement signal; a setting means for setting a reference value which progressively increases from a very small value close to zero as a physical amount related to said vehicle velocity becomes greater; a judging means for making judgement as to whether said angular frequency is larger or smaller than said reference value by making a size comparison therebetween; and a processing means for controlling the direction of the movement in said actuator mechanism on the basis of the result of judgement by said judging means and controlling the amount of the movement in said actuator mechanism in response to the level of said steering wheel displacement signal such that: (a) when said angular frequency is smaller than said reference value, the steer angle of said rear wheels corresponding to the level of said steering wheel displacement signal is generated in the same direction as the steer angle of said front wheels; and (b) when said angular frequency is larger than said reference value, the steer angle of said rear wheels corresponding to the level of said steering wheel displacement signal is generated in the direction counter to a direction of steer angle of said front wheels.
Claim 6
Dependent Claim
29 words
A rear wheel steer angle controlling apparatus according to Claim 4, wherein said calculating means, judging means and processing means of said control means comprises a phase shifting means.
Claim 7
Dependent Claim
32 words
A rear wheel steer angle controlling apparatus according to Claim 2, wherein the rate of change of the reference value which varies in accordance with said physical amount signal is made adjustable.
Claim 8
Dependent Claim
38 words
A rear wheel steer angle controlling apparatus according to Claim 1 or 4, wherein the ratio of the magnitude of steer angle of said rear wheels to the level of said steering wheel displacement signal is made adjustable.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.