Apparatus for controlling steer angle of rear wheels of vehicle

A rear wheel steer angle controlling apparatus for automatically controlling the steer angle of rear wheels of a vehicle by controlling an actuator mechanism for generating the steer angle of 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;
• a judging means for judging a rotation speed of said steering wheel from said steering wheel displacement signal;
• a physical amount detecting means for detecting a physical amount related to a velocity of said vehicle and outputting a physical amount signal;
• and
• a controlling means for controlling said actuator mechanism in accordance with a result of judgement by said judging means and said physical amount signal such that:
• (a) when said steering wheel is operated at a high rotation speed, a steer angle of the rear wheels is formed in the direction counter to a direction of steer angle of the front wheels such as to provide a small radius of turning circle of said vehicle when said physical amount is small and, when said physical amount is large, said steer angle of the rear wheels is determined such as to provide a greater radius of turning circle than that obtained when said physical amount is small;
• and
• (b) when said steering wheel is operated at a low rotation speed, a steer angle of the rear wheels is formed in the same direction as the steer angle of the front wheels.

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;
• a judging means for judging a rotation speed of said steering wheel from said steering wheel displacement signal;
• a physical amount detecting means for detecting a physical amount related to a lateral displacement of said vehicle and outputting a physical amount signal;
• and
• a controlling means for controlling said actuator mechanism in accordance with a result of judgement by said judging means and said physical amount signal, such that a steer angle of rear wheels is genrated as the sum of:
• (a) a first angle proportional to said steering wheel displacement and set in the direction counter to a direction of steer angle of the front wheels when said steering wheel is operated at a high rotation speed and in the same direction as the steer angle of the front wheels when said steering wheel is operated at a low rotation speed;
• and
• (b) a second angle proportional to said physical amount and set in the same direction as generation of said physical amount.

A rear wheel steer angel 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;
• a judging means for judging a rotation speed of said steering wheel from said steering wheel displacement signal;
• a physical amount detecting means for detecting a physical amount related to a lateral displacement of said vehicle and outputting a physical amount signal;
• a steer angle detecting means for detecting the steer angle of the rear wheels and outputting a steer angle signal;
• and
• a controlling means for controlling said actuator mechanism in accordance with the result of judgement by said judging means, said physical amount signal and said steer angle signal, such that a steer angle of the rear wheels is generated as the sum of:
• (a) a first angle proportional to said steering wheel dislacement and set in the direction counter to a direction of steer angle of the front wheels when said steering wheel is operated at a high rotation speed and in the same direction as the steer angle of the front wheels when said steering wheel is operated at a low rotation speed;
• and
• (b) a second angle proportional to said physical amount and set in the same direction as generation of said physical amount.