Nissan Motor Company Limited

Kazunori Mori

Fukashi Sugasawa

Kenji Kawagoe

Namio Irie

Hiroshi Mouri

Junsuke Kuroki

Hiroshi Mori

An automotive vehicle rear wheel steering system steers the rear wheels in accordance with front wheel steering, with a steering angle which corresponds to the sum of proportional and differential components of the front wheel steering amount. A detecting unit detects a front wheel large steering condition in which the front wheels have been steered with an amount in excess of a preset value. A correction unit corrects at least one of the above-mentioned components in the front wheel large steering condition, in such direction as to improve transient turning response characteristic of the vehicle. An actuator unit steers the rear wheels by a steering angle based on at least one component which has been corrected in the large front wheel steering condition. The turning-round property and maneuverability of the vehicle can be prevented from degradation despite the rear wheel steering under the front wheel large steering condition.

Rear wheel steering system for automotive vehicle

A system for controlling the steering angle for the rear wheels of a vehicle is provided. This system includes an angle sensor for sensing a steered angle, a vehicle speed sensor, and a steering angle controller. The steering angle controller is adapted for controlling steering of the rear wheels based on a target steering angle derived according to a transfer function in view of suspension steering to improve yaw damping in ranges of high steering frequency.

Rear wheel steering angle control system for vehicle

A system for controlling the steering angle for the rear wheels of a vehicle is provided. This system includes an angle sensor for sensing a steered angle, steered angular velocity, and steered angular acceleration, a vehicle speed sensor, and a steering angle controller. The steering angle controller is adapted for controlling steering of the rear wheels so as to vary the position where the side slip angle of the vehicle becomes zero with respect to the center of gravity based on the steered angle, steered angular velocity, steered angular acceleration, and vehicle speed to improve manoeuverability of the vehicle in cornering.

Rear wheel steering angle control system for vehicles

A steering control system for a vehicle includes an actuator for steering rear wheels in response to a control signal, a steering angle sensor, a vehicle speed sensor, and controller for controlling a rear wheel steer angle by producing the control signal according to the following transfer function; ##EQU1## where a.sub.0, a.sub.1, a.sub.2, a.sub.3, a.sub.4 and a.sub.5 are parameters whose values are determined by the vehicle speed, vehicle constants determined by the specification of the vehicle, and desired constants representing a preset desired steering characteristic.

Four wheel steering system for vehicle

A four wheel steering control system for a vehicle includes a steering wheel angle sensor, a vehicle speed sensor, and a controller for determining auxiliary front and rear wheel steer angles .delta..sub.f and .delta..sub.r with respect to a basic front wheel steer angle .delta..sub.o proportional to a steering wheel angle .theta. in accordance with the following transfer functions: ##EQU1## where s is a Laplace transform variable, and K.sub.f, K.sub.r, T.sub.f and T.sub.r are constant determined by the vehicle speed and the specifications of the vehicle.

Four wheel steering control system for vehicles

A method of steering a vehicle having a set of steerable front wheels and a set of steerable rear wheels. The front and rear wheels are both secondarily steered in addition to a main steer of the front wheels caused by an operation of a front wheel steering gear in response to an operation of a steering wheel. The method comprises providing to the front wheels a secondary steer angle corresponding to at least a differentiated value of a steer angle of a steering wheel in such a way as to increase an overall steer angle of the front wheels and providing to the rear wheels a secondary steer angle proportional to the steer angle of the steering wheel and in the same direction as the steer angle of the front wheels.

Vehicle having secondarily steered front and rear wheels

A rear wheel steer angle control system for a vehicle includes a vehicle speed sensor, a steering wheel angle sensor and a controller for controlling a rear wheel steer angle .delta..sub.r (s) with respect to a front wheel steer angle .delta..sub.f (s) in accordance with .delta..sub.r (s)/.delta..sub.f (s)=(K+Tls)/(1+T2s), where K, T1 and T2 are control parameters each of which is a function of the vehicle speed, and includes a quantity representing a distance of a zero sideslip angle position from a center of gravity of the vehicle. The quantity representing the distance of the zero sideslip angle position at which the sideslip angle is to be zero, may be fixed at a constant value, or may be adjusted in accordance with any one or more of the vehicle speed, the steering wheel angle and the time rate of change of the steering wheel angle.

Rear wheel steer angle control system for vehicle

A system for controlling the steering angle of the rear wheels of a four-wheel-steerable motor vehicle has a controller which steers the rear wheels in a manner to satisfy the following equation: ##EQU1## where: .delta.f(s): Laplace transform of the front wheel steering angle;

System for controlling the steering angle of the rear wheels of a

A steering control system comprises means for performing a secondary steer of front and rear wheels by angles computed using a steer angle .theta., steer angle angular velocity .theta. and vehicle speed V from the following formulas, ##EQU1## where .delta.f is a front wheel secondary steer angle, .delta.r is a rear wheel secondary steer angle, N is a steer gear ratio and Kf, Kr, Tf and Tr are control constants which are functions of vehicle speed. In accordance with the present invention, the control system is provided with means for correcting the control constants Kf and Kr in such a way that the control constants Kf and Kr become a steady-state value when the steer angle is larger than a predetermined value and become smaller than the steady-state value when the steering angle becomes smaller than the predetermined value, means for correcting the control constants Tf and Tr in such a way that the control constants Tf and Tr become a steady-state value when the steer angle is larger than a predetermined value and become smaller than the second mentioned steady-state value when the steer angle becomes smaller than the second mentioned predetermined value, means for correcting the control constants Kf and Kr in such a way that the control constant Kr reduces at the rate larger than the control constant Kf as the steer angle reduces from the first mentioned predetermined value, and means for correcting the control constants Tf and Tr in such a way that the control constant Tf reeduces at the rate larger than the control contant Tr as the steer angle reduces from the second mentioned predetermined value.

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Ebina, Japan

Kazunori Mori