Abstract: A wheel braking system comprises a motor driven gear pump, a relief line connecting the pump discharge to the pump intake, a wheel brake unit connected to the pump discharge, and a flow restriction in the relief line. A control unit controls the motor for the pump in response to an output signal of a brake pedal sensor. The brake pedal sensor generates the output signal indicative of the brake pedal stamping force. The control unit determines a desired motor speed for the sensed brake pedal stamping force and operates the motor.

Abstract: A vehicle steering system includes a front hydraulic actuator for steering front wheels, a rear hydraulic actuator for steering rear wheels, a front control valve of an open center type for controlling the fluid pressure of the front actuator, a rear control valve of the open center type for controlling the fluid pressure of the rear actuator, a common fluid pressure source, and a flow dividing valve for dividing a fluid flow from the common pressure source into two flows directed to the front and rear control valves so that the front and rear control valves of the open center type can control the fluid pressures independently and accurately.

Abstract: 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.

Abstract: A suspension and steering control system includes a mode selection which enables a normal mode wherein the suspension is conditioned to produce a soft damping and sufficient power assistance to the steering to produce light steering characteristics and a sporty mode wherein the suspension is conditioned to produce a firm ride and the power assistance to the steering lowered to produce heavier steering characteritics. The system further includes an arrangement for sensing parameters which are related to the attitude of the vehicle and/or the suspension thereof and for (a) during the normal mode, temporarily conditioning the suspension to produce the firm ride characteristics if the attitude of the vehicle is apt to change beyond a predetermined amount, and for (b), during the sporty mode, temporarily conditioning the suspension to produce the soft ride in the event that no substantial changes in the vehicle attitude related parameters are sensed.

Abstract: An automotive suspension system has a roll stablizer with an adjustable torsion modulus. The torsion modulus of the stabilizer is adjusted depending upon road surface conditions and other parameters. A controller is associated with the stabilizer to adjust its torsion modulus. When the vehicle is moving on a relatively smooth road surface, the torsion modulus of the stabilizer is adjusted toward to a relatively high value. On the other hand, when the vehicle travels along a rough road, the torsion modulus is adjusted toward a lower value.

Abstract: 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.

Abstract: A suspension control system can precisely control the damping characteristics of vehicular suspension for successfully and satisfactorily providing anti-dive and anti-rebound feature. The suspension control system is adapted to detect vehicle deceleration on the basis of a variation of a vehicle speed and to compare the vehicle speed with a predetermined vehicle speed criteria across which damping characteristics of the vehicular suspension vary between a harder suspension mode and a softer suspension mode. The vehicle speed criteria is variable depending upon vehicle deceleration so that the criteria becomes higher when the magnitude of deceleration is greater than a predetermined level. By hardening the suspension at an earlier timing during relatively abrupt deceleration of the vehicle, the magnitude of nose dive is reduced and the magnitude of rebounding motion after nose-dive can be reduced. This assures riding comfort by reducing the magnitude of pitching behavior of the vehicle front end.

Abstract: A suspension control system is able to precisely adapt damping characteristics to the road condition, even when the vehicle passes over bump, manhole, hole and so forth. The suspension control system includes a road sensor which produces a road condition indicative signal. A controller is adapted to recognize bump, manhole, hole and so forth which causes temporary bounding and rebounding motion for the vehicle, on the basis of the road condition indicative signal from the road sensor. The controller produces a control signal to harden damping characteristics of suspension when bump, manhole, hole and so forth is detected with a given delay time. The delay time for changing damping characteristics is different at the front and rear suspension from each other so that each of the front and rear suspension can be stiffened at a good timing.

Abstract: 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.

Abstract: 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.

Abstract: An automotive vehicle suspension having a damper with variable damping characteristics, specifically, an adjustable damping force. A controller responds to an application and release of the vehicle brakes by increasing the damping force, to suppress nose-dive of the vehicle at the beginning of braking and to suppress pitching motion of the vehicle at the end of braking.

Abstract: A suspension control system includes a road surface sensor which produces a road condition indicative signal. A controller detects bounding and rebounding motions of the vehicle suspension on the basis of the road condition indicative signal from the road sensor. The controller monitors when the bounding and rebounding motion exceeds a predetermined level and when its frequency falls within a given frequency range. These conditions reflect typical vehicle body behavior during travel along an undulating road, in which case, the controller produces a control signal to stiffen the suspension system. This suppresses pitching motion of the vehicle on undulating road so as to satisfactorily and successfully provide good riding comfort.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A suspension control system includes a suspension system variable of stiffness and/or damping characteristics, a road sensor producing a road condition indicative signal and a controller for controlling the stiffness and/or damping characteristics of the suspension system depending upon the road condition indicative signal value and the vehicle speed indicative signal value. The controller is detective of the vehicle speed in a predetermined normal speed range which is defined by a lower speed criteria and an upper speed criteria, for generally maintaining the stiffness or damping characteristics of the suspension in relatively soft. The controller is detective of the vehicle speed indicative signal value smaller than the foregoing lower speed criteria to increase sensitivity of the road sensor and/or harden the suspension system at harder level than that in the normal speed range when the roughness of the road surface beyond a rough road criteria.

Abstract: 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.

Abstract: A suspension control system for automotive vehicles automatically adjusts the damping strength of variable shock absorbers or other dampers in accordance with road surface conditions. The sensor signal reflects vertical displacement of the vehicle body from the road surface. The sensor signal is compared to a corresponding reference level which is variable depending upon a vehicle speed. The results of comparison give an indication of the degree and scale of irregularities in the road surface. The comparison information is sent to a suspension system controller which causes actuation of the shock or other dampers absorbers to a stiffer mode of operation when road surface roughness requiring harder suspension is recognized.

Abstract: A swing arm suspension for automotive vehicle has a suspension arm pivotably connected to a suspension member for rotation about a substantially horizontal pivot axis. A lateral rod is connected to the suspension arm at one end thereof via a bushing and to a suspension member at the other end via another bushing. The position where the lateral rod is connected to the suspension member and to the vehicle body are offset from the pivot axis of the suspension arm. The position is chosen such that the lateral rod serves to provide roll compensating force for the suspension to satisfactorily and successfully restrict roll or compliance steering effects in the toe-out direction and to prevent positive camber. The lateral rod is adapted to be connected to the suspension member at such a position as to cause toe-in and/or negative camber.

Abstract: An automatic vehicle height-adjusting system is applied to a vehicle including a sprung mass and an unsprung mass in contact with a road surface, the sprung mass being supported on the unsprung mass via a spring or the like. The system includes a sensor, which senses the distance between the sprung mass and the road surface and generates a distance signal indicative thereof. In response to the distance signal, a first discriminator or comparator determines whether or not the distance is less than a first predetermined value, and generates a first comparison signal indicative thereof. In response to the distance signal, a second discriminator or comparator determines whether or not the distance is greater than a second predetermined value, and generates a second comparison signal indicative thereof. The second predetermined value is chosen to be greater than the first predetermined value.