Nissan Motor Company Limited

Yasuji Shibahata

Yasumasa Tsubota

Namio Irie

Yukio Fukunaga

Kenji Nakamura

Junsuke Kuroki

Kazuo Ikawa

Takaaki Uno

Yohsuke Akatsu

Hirotsugu Yamaguchi

Tokiyoshi Yanai

Yutaka Aoyama

Moritsune Nakata

Megumu Higuchi

Hiroshi Tonomura

Yuji Okuyama

Yosuke Akatsu

In addition to a conventional steering system for steering a vehicle through the front wheels in accordance with an angular displacement of the steering wheel, the vehicle is equipped with a negative feedback steering control system which steers the vehicle through the front or rear wheels in accordance with an instantaneous yaw rate of the vehicle. The feedback system has a vehicle behavior sensor for sensing the yaw rate, and an control circuit which determines an actual quantity which is equal to the yaw rate or a linear combination of the yaw rate and the time derivative of the yaw rate and a reference quantity which is a function of the angular displacement and the vehicle speed, so designed as to be approximately equal to the yaw rate if there is no disturbance. The control circuit produces a feedback signal proportional to a difference between the actual quantity multiplied by a first coefficient and the reference quantity multipled by a second coefficient. In response to the feedback signal, an actuator corrects the direction of the front or rear wheels in such a direction as to reduce the yaw rate. A lateral acceleration of the vehicle may be used in place of the yaw rate.

Auxiliary steering system for wheeled vehicle

In a steering system in which both front and rear wheels are steerable, the rear road wheels are adapted to be turned in the direction opposite to the direction of turning of the front road wheels only when a steering wheel is turned with a torque or effort larger than a predetermined value.

Vehicle steering system

A lower arm and upper links of a double wishbone type suspension are arranged so that the resulting king pin axis about which a road wheel is pivotal, intersects the wheel rotational axis at or close to the wheel center so as to selectively minimize, neutralize or reverse the toe-out effect produced by a force which acts through the wheel center in the aft direction of the vehicle. The lateral rod which controls the orientation of the road wheel is arranged at a predetermined angle to control the amount of toe-in induced by the application of the above mentioned force and a force which acts laterally inboard along the wheel rotational axis.

Wishbone suspension for automotive vehicle

A vehicle steering control system for steering both front and rear wheels is so arranged that a transfer function between a driver's steering input and a front wheel steering angle, and a transfer function between the steering input and a rear wheel steering angle are differentiated from each other so as to obtain an optimum cornering characteristic of the vehicle. The system has a steering input sensor, a vehicle speed sensor, means for determining the transfer function for the front wheels from a steering frequency and a vehicle speed, means for determining the transfer function of the rear wheels, a front wheel actuator for steering the front wheels, and a rear wheel actuator for steering the rear wheels. The means for determining the transfer function of the rear wheels may be an electronic circuit, or a hydraulic fluid flow restrictor such as an orifice, or a mechanical gearing.

Four-wheel steering control system for vehicle

A method of controlling an automotive vehicle is disclosed whereby a steering characteristic of the vehicle is automatically adjustable to a feature of the driver's steering the vehicle. The feature of the driver's steering the vehicle is detected in terms of a driver's technique or habit in manipulating a steering wheel or a motion characteristic of the vehicle such as a yaw rate or a lateral acceleration resulting from a driver's manipulating the steering wheel. A pair of steerable road wheels, such as a pair of front road wheels, are steered through an angle which is proportioned to an angle through which the steering wheel is manually turned at a ratio which is variable with variation in the feature of the driver's steering the vehicle.

Method of controlling vehicle

A vehicle steering system in which both front and rear road wheels are turnable in opposite directions upon low speed running and in the same direction upon high speed running, and the angle of turning of the rear road wheels for a given steering effort on a steering wheel is varied so that a large angle of turning of the rear road wheels is obtained during low speed running and a small angle of turning of the rear road wheels is obtained during high speed running.

A wheeled vehicle is equipped with a feedforward steering control system which steers the vehicle through front or rear road wheels in accordance with a driver's steering input such as an angular displacement of a steering wheel, and a negative feedback system which senses a turning behavior of the vehicle such as a yaw rate or a lateral acceleration, and steers the vehicle through the front or rear wheels in such a negative direction as to reduce the turning behavior. The feedforward system may control the angular direction of the front or rear wheels in accordance with a linear combination of the steering input and the time derivative of the steering input, or may control the angular directions of both of the front and rear wheels in accordance with different transfer functions between the steering input and the front and rear wheel angles. The negative feedback system is combined with the feedforward system in various ways to provide desired characteristics of the turning behavior. The negative feedback quantity determined by the negative feedback system may be proportional to the sensed turning behavior, or may be determined in accordance with the difference between the sensed turning behavior, and the reference turning behavior calculated from the vehicle speed and steering input.

Steering control system for wheeled vehicle

A vehicle is equipped with a power steering control system and a compliance steer control system. Hydraulic fluid pressurized by a hydraulic pump is controlled in pressure by a fluid control valve, and the thus controlled hydraulic fluid is selectively directed through a directional control valve to at least one of the power steering system and the compliance steer control system in accordance with vehicle speed, thereby stopping fluid supply to the power steering system in a high vehicle speed range while to the compliance steer control system in a low vehicle speed range.

Vehicle steering control system

In a vehicle the steering system includes a steering gear housing transversely mounted relative to the vehicle body by means of a plurality of gear housing mount insulators. Each of the gear housing mount insulators elastically supports the gear housing in such a manner as to allow transverse displacement of the gear housing with respect to the vehicle body. A damper is provided to restrain the transverse displacement allowed by the gear housing mount insulators.

Steering system controlling transverse displacement of a gear housing

A rear wheel steering control system which determines a target rear wheel steering angle in accordance with a steering angle of front wheels of the vehicle and steers the rear wheels so that the rear wheel steering angle is maintained equal to the target rear wheel steering angle, and is arranged not to decrease the difference between the target angle and the actual rear wheel steering angle immediately to zero, but to decrease the difference gradually in accordance with a distance traveled by the vehicle, in order to prevent the rear wheels from being steered too much in a direction opposite to a steered direction of the front wheels especially when the vehicle speed is low, and thereby prevent the rear of the vehicle from bumping against an object lying alongside the vehicle.

Rear wheel steering control for vehicle

Extensible hydraulic cylinders are used for attaching a stabilizer bar to a vehicle body so that attaching portions of the stabilizer bar are movable toward and away from the vehicle body as the hydraulic cylinders extend and contract, whereby to adjustably change the effectiveness in accordance with variation of running condition of the vehicle.

Stabilizer for an automotive vehicle

A vehicle is equipped with a rear wheel control device including hydraulic actuators for controllably turning rear wheels under influence of hydraulic fluid supplied thereto from a hydraulic pump. Turning the rear wheels is made in one of first and second directions which are opposite to each other, in response to steering effort applied to a steering wheel. The change-over operation of the rear wheel turning between the first and second directions takes place upon substantially stopping supply of the hydraulic fluid to the actuators, thereby preventing shock during the turning direction change-over operation.

Vehicle steering control system and method of operating same

A vehicle is equipped with a power steering system having a power cylinder, and a vehicle control mechanism having an actuator. The power cylinder and the actuator are supplied with hydraulic fluid under pressure through first and second control valves, respectively, to independently control the power steering control system and the vehicle control mechanism. The first and second control valves are configurated integrally with each other to form a single control valve assembly, thereby providing advantages of weight, production cost, and required space reductions.

Vehicle control system

A vehicle steering system comprises a power cylinder drivingly connected to front wheels and forming part of a power steering system, and an actuator drivingly connected to rear wheels and forming part of a so-called compliance steer control system. The power cylinder and the actuator are supplied with hydraulic fluid from a pump through first and second control valves which are operated in response to the turning effort applied to a steering wheel. Additionally, a flow dividing valve is provided to distribute the fluid from the pump into the first and second control valves in a predetermined flow dividing ratio, thereby allowing effective independent operations of the power steering system and the compliance steer control system without affecting each other.

An independent rear suspension system according to the invention comprises two parallel lateral links having outboard ends mounted via respective elastic bushes on a wheel support carrying a road wheel and inboard ends mounted via respective elastic bushes on a vehicle body. The inboard end of the front lateral link is mounted about an inclined pivot axis. This pivot axis is so inclined from the vehicle longitudinal axis as to provide an arrangement whereby when a force is applied to a portion of the front lateral link near the inboard end thereof in a direction along the inclined pivot axis, the front lateral link moves transversely with respect to the longitudinal axis of the vehicle further than the rear lateral link does, causing a toe angle of the road wheel to vary.

Growing community of inventors

Yokohama, Japan

Yasuji Shibahata