Abstract: A control system for a controlled vehicle has a steering wheel angle sensor, a vehicle speed sensor, a turning behavior sensor such as a side speed sensor and a yaw rate sensor, an actuator such as a hydraulic system for altering a rear wheel steer angle in accordance with a desired angle value, and a controller such as a microcomputer for determining the desired angle value by solving three distinct vehicle models. The controller first solves a reference model representing a desired vehicle to determine a desired vehicle response to the steering wheel angle and vehicle speed, and then solves a first actual model representing the actual controlled vehicle to determine the desired rear wheel steer angle value required to cause the controlled vehicle to produce the desired response. The controller further solves a second actual vehicle model representing the controlled vehicle to estimate the turning behavior resulting from the desired rear wheel steer angle, identifies front and rear wheel cornering powers of the second actual model by comparing the estimated and sensing turning behavior, and then adjusts the front and rear wheel cornering powers gradually in accordance with the result of the identification.

Abstract: A four wheel drive system of a vehicle has a multiple disc friction type transfer clutch capable of varying torque transmitted to front wheels, a hydraulic circuit for varying an engagement force of the transfer clutch by supplying a fluid pressure to the transfer clutch, front and rear wheel rotational speed sensors, a sensor for sensing a turning radius corresponding to a steering angle, and a control unit for varying the torque transmitted to the front wheels by sending a control signal to the hydraulic circuit in accordance with a front and rear wheel speed difference, a vehicle speed and the turning radius.

Abstract: A vehicle steering control system has a steering wheel angle sensor, a vehicle speed sensor, a control unit and an actuator for steering either (or both) of front and rear wheel pairs of a controlled vehicle. The control unit determines desired values of yaw rate and lateral acceleration corresponding to the sensed steering wheel angle and vehicle speed by using at least one desired mathematical vehicle model having desired vehicle response characteristics. Then, the control unit determines a desired value of a front or rear wheel steer angle (or both of the front and rear wheel angles) theoretically required to achieve the desired value of the yaw rate, and another desired value of the steer angle theoretically required to achieve the desired value of the lateral acceleration. Finally, the control unit determines a weighted average of two desired values of the steer angle by using weights which are functions of vehicle speed and/or steering wheel angular speed. The actuator steers the front or rear wheel pair so that an actual steer angle is maintained equal to the weighted average.

Abstract: A four wheel drive system of a vehicle has a transfer clutch capable of varying clutch torque transmitted therethrough from an engine to front wheels. The clutch torque is controlled by a driving force distribution control unit in accordance with a front and rear wheel speed difference determined from signals from front and rear wheel speed sensors. Preferably, the control unit controls a distribution ratio of a front wheel driving force to a rear wheel driving force by controlling the clutch torque of the transfer clutch in such a manner that the distribution ratio decreases as the wheel speed difference increases when the wheel speed difference is positive, that is the front wheel speed is higher than the rear wheel speed, and that the distribution ratio increases as the absolute value of the wheel speed difference increases when the wheel speed difference is negative.

Abstract: Automatic measurement of toe setting, thrust angle and run-out compensation provide data for automatic adjustment of the toe planes of front wheels of a motor vehicle. Vehicle stabilizers are employed for moving the vehicle so that the center line of the vehicle is coincident with the center line of the toe-set alignment system. Transducer units derive static toe angles and camber, as well as dynamic run-out compensation values for all from wheels of the vehicle.

Abstract: In a front and rear wheel steering device contive for vehicle in which the steering angle ratio of the rear wheels relative to the front wheels is variable according to the vehicle speed, provision of a manual selection means for fixing the steering angle ratio to certain fixed values which may be either positive or negative can greatly improve the maneuverability of the vehicle in both high speed and low speed ranges. However, inadvertent manual selection of the steering angle ratio is not desirable since it may cause a sudden change in the steering angle of the rear wheels. Therefore, this invention provides means for preventing the manual selection of the steering angle ratio when it is not proper. This means may be an active prohibition control of manual steering angle ratio selection means, an alarm to warn the driver or a vehicle speed control which limits the vehicle speed. The situations in which the manual selection of the steering angle ratio is not proper may be determined from such factors as vehicle acceleration, transmission shift position, steering rate and so on.

Abstract: A rear wheel steering hydraulic cylinder is arranged in a rear wheel steering apparatus to steer rear wheels to the right and left. When a front wheel steering angle detected by a front wheel steering angle sensor exceeds a predetermined value, the hydraulic cylinder is actuated to steer the rear wheels in a direction opposite to that of the front wheels. When the rear wheel steering angle detected by a rear wheel steering angle sensor is changed in response to the front wheel steering angle, the hydraulic cylinder is not activated, thereby not steering the rear wheels.

Abstract: A four wheel steer vehicle is provided with a suspension control system for controlling at least one suspension characteristic, one or more sensors for sensing a change in suspension characteristics by sensing a condition of the suspension control system, and a controlling element for varying a ratio of a rear wheel steer angle to a steering wheel angle in accordance with the suspension characteristic. Examples of the suspension characteristics are spring constants of front and rear suspensions, heights of the front and rear suspensions, damping forces of the front and rear suspensions, roll stiffnesses of the front and rear suspensions, and front wheel alignment angles such as camber and toe-in.

Abstract: A system for providing toe and camber adjustment for a wheel drum which is normally fixed in location on a vehicle wherein one end of a control arm is relatively fixedly mounted on the wheel drum and the other end of the control arm is mounted for movement in an arcuate path about a relatively fixed axis for changing the angular relationship between the longitudinal axis of the vehicle and the rotational axis of the wheel drum so as to vary the toe and camber of the wheel drum.

Abstract: An embodiment of steering arrangement for motorcycles wherein the rear wheel is supported for steering movement and is mechanically coupled to the mechanism for steering the front wheel so that both wheels will be steered in unison. The rear wheel is driven by means of a shaft drive.

Abstract: A vehicle is equipped with a four wheel drive system having a transfer, a four wheel steer system for steering front wheels and rear wheels, a sensor for sensing a condition of a driving torque distribution between the front wheels and rear wheels, by sensing a condition of the four wheel drive system, and a controller for controlling a rear wheel steer angle in accordance with the condition of the driving torque distribution by commanding the four wheel steer system in such a manner as to maintain the desirable weak understeer characteristic irrespective of change in the driving torque distribution at least when a vehicle speed is greater than a predetermined value.

Abstract: A rear wheel steering apparatus for a vehicle has a vehicle speed sensor for detecting a vehicle speed, a front wheel steer angle sensor for detecting a steer angle of front wheels of the vehicle, a rear wheel steer angle driving device for varying the steer angle of each of the right and left rear wheels, and a rear wheel steer angle controller for controlling the rear wheel steer angle driving device. The controller is adapted to calculate a toe-in quantity of the rear wheels as an increasing function of the vehicle speed, calculate a steer angle of each of the right and left rear wheels by the use of the vehicle speed and the steer angle of the front wheels, and control the rear wheel steer angle driving device on the basis of results of these calculating operations such that the steer angle of each of the right and left rear wheels changes by a predetermined angle. Accordingly, it is possible to improve the response to the steering input for turning the vehicle.

Abstract: A device is used to adjust toe angle of a vehicle wheel connected to a car by a suspension system having at least one control arm transversely disposed to the longitudinal axis of the vehicle. The control arm is attached to the wheel at one end and pivotally attached to an underside of the vehicle at another end by a bolt. The device displaces the bolt of the control arm from its original position, thereby adjusting the toe angle of the wheel.

Abstract: A vehicle is provided with a system for steering front wheels, a system for steering rear wheels, a vehicle speed sensor and a controller. By sending a command signal to the rear wheel steering system, the controller steers the rear wheels in an in-phase mode in which the rear wheel steer direction is the same as the front wheel steer direction when the vehicle speed is high, and in a fixed mode in which the rear wheels are not steered at all or in an opposite phase mode in which the rear wheel steer direction is opposite to the front wheel steer direction when the vehicle speed is low. There is further provided with means for detecting a failure in the rear wheel steering system, vehicle speed and controller. The controller is arranged to steer the rear wheels always in the in-phase mode irrespectively of the vehicle speed if a failure is detected.

Abstract: A suspension has two arms disposed laterally of a car body and spaced mutually in front and to the rear of each other in the direction of the length of the car body. A carrier is rotatably connected about a vertical axis to the respective outer ends of the arms to support a wheel. An apparatus for adjusting a toe angle of the wheel includes a toe adjuster connected to an inner end of one of the two arms and provided on the car body to displace the inner end in three dimensions. An actuator is provided for operating the toe adjuster.

Abstract: A steering system for a vehicle comprises a front wheel turning mechanism for turning the front wheels in response to operation of a steering wheel, a steering ratio changing mechanism inserted into the front wheel turning mechanism to change the ratio of the turning angle of the steering wheel to the turning angle of the front wheels, and a vehicle speed sensor for detecting the vehicle speed The steering ratio changing mechanism is controlled to increase the ratio as the vehicle speed increases, and as the vehicle speed increases, the control speed of the steering ratio changing mechanism is lowered

Abstract: A four wheel drive vehicle with an anti-lock braking system comprising front and rear axles coupled together by a power transmission assembly capable of transmitting the braking force acting upon the front wheels to the rear wheels. A power unit is drivingly connected to the power transmission assembly. A hydraulic braking system controls the hydraulic pressure applied to each wheel brake and an anti-lock control system controls the hydraulic braking pressure such that the braking pressure is reduced when a wheel is about to become locked. The anti-lock control system includes a front wheel control section to control the hydraulic pressure applied to the front wheel brakes and a rear wheel control section to control the hydraulic pressure applied to the rear wheel brakes. The front wheel and rear wheel control sections are connected so that in cases where the braking force acting upon the front wheels is transmitted to the rear wheels, i.e. in four wheel drive, the hydraulic braking pressure to the rear wheel brakes is reduced when the rear wheeels are about to be locked and the hydraulic pressure applied to the front wheel brakes has been reduced for at least a predetermined period of time.

Abstract: A four wheel steer vehicle is equipped with a steering control system for controlling a rear wheel steer angle so that a rear end of the vehicle follows a path along which a front end moves. The control system includes a front wheel steer angle sensor, a controller for producing a control signal representing a desired rear wheel steer angle and an actuator for altering the rear wheel steer angle in response to the control signal produced by the controller. The controller estimates the path of the front end by calculating a value of a course angle of the front end from the front wheel steer angle each time the vehicle travels a predetermined short distance, and storing a predetermined number of the course angle values which are most recently determined. The controller determines the desired rear wheel steer angle so that the course angle of the rear end equals the oldest one of the stored course angle values of the front end.

Abstract: A wheel suspension for steerable wheels, especially front wheels of motor vehicles, with a wheel carrier supporting the wheel; an upper cross guide member and a tie rod displaceable in its longitudinal direction are pivotally connected at this wheel carrier. The lower cross guide member supporting the vehicle support spring is connected by way of a corner-rigid pivot joint with an intermediate member, at which in turn the wheel carrier is supported by way of a corner-rigid pivot bearing having approximately vertical axis and a possibility of displacement in the direction of this axis. The wheel carrier and the intermediate member are each pivotally connected with an approximately vertical tension rod. The tension rod is extended beyond its pivotal connection with the intermediate member. A strut extending obliquely to the vehicle longitudinal direction, as viewed in plan view, is pivotally connected with its one end at the thus formed extension while it is pivotally connected with its other end at the vehicle body. A far-reachingly translatory movement can be superimposed in this manner on the purely rotary movement of the wheel, from which results a center of rotation for the steering movement of the wheel which is displaced to the vehicle outside with respect to the real joint connections of the wheel carrier. Additionally drive and brake moments which are exerted on the wheel carrier, can be favorably introduced into the vehicle body by way of the strut in conjunction with a vertical support strut.

Abstract: A four-wheel steering system for an automotive vehicle includes a front wheel steering mechanism operable in response to a steering effort applied thereto to steer a pair of dirigible front road wheels, a rear wheel steering mechanism including an axially displaceable operation rod operatively connected at the opposite ends thereof with a pair of dirigible rear road wheels to steer the rear road wheels, and a connecting mechanism assembled in combination with the rear wheel steering mechanism and being drivingly connected to the front wheel steering mechanism for effecting axial displacement of the operation rod in response to operation of the front wheel steering mechanism and for controlling the steering angle ratio and direction of the rear road wheels relative to the front road wheels. The rear wheel steering mechanism is in the form of a power assisted steering mechanism which includes a hydraulic power cylinder integrally provided with the operation rod, and a control valve operatively connected to the connecting mechanism and the operation rod to control fluid under pressure supplied into the power cylinder in accordance with the mode of operation of the connecting mechanism.

Abstract: Measuring device, in particular for determining the wheel positions of a motor vehicle in driving mode, having a joint mechanism which, on the one hand, can be connected to the wheel or the wheel carrier and, on the other hand, is connected to the support part (7). The joint mechanism has a total of six possibilities of rotary movement, at least five possibilities of movement thereof being detected by one angle resolver. The measuring device can be used to determine the toe and camber of a wheel and the coordinates of a point on the wheel axis (8) or of an arbitrary point connected to the wheel carrier even during driving operation.

Abstract: A four-wheel motor vehicle has a frame assembly, a pair of steerable front wheels, a pair of rear wheels, and leveling mechanisms. The four-wheel motor vehicle includes front wheel supporting means angularly movably mounted on the frame assembly and supporting the front wheels, the front wheels being supported at a positive caster angle by the front wheel supporting means when the front wheel supporting means is held at an angle to the frame assembly, rear wheel supporting means angularly movably mounted on the frame assembly and supporting the rear wheels, at least one damper interconnected between the frame assembly and the front wheel supporting means, and at least one damper interconnected between the frame assembly and the rear wheel supporting means. The leveling mechanisms are combined with the dampers for adjusting distances between the frame assembly and the front and rear wheel supporting means when the dampers are inoperative.

Abstract: Apparatus for reducing the production of water spray by a wheel (14) of a motor vehicle comprises a deflector plate (40) located in front of the wheel and extending horizontally in a transverse direction over a width greater than that of the tyre carried by the wheel (14) while sloping in the longitudinal direction from a forward end above the top of the wheel (14), downwardly and rearwardly to a location in proximity to the front edge of the wheel (14) The deflector plate (40) serves to separate the flow of air towards the front edge of the wheel (14) from drops of water lifted upwardly by the rear edge of the wheel (14)

Abstract: PURPOSE: To improve the acceleration quality of a car, its brake characteristic and drivability, by constituting the car such that an actuator for driving hydraulically operated front and rear wheel differential gears and center clutch is controlled by a steering angle and front and rear wheel speeds. CONSTITUTION: A control device respectively detects a speed of each wheel 1-1W1-4 by sensors 17-1W17-4 and a steering angle by a sensor 19 to be input to a control circuit 15. The control circuit 15 performs a decision of the wheel to be in a racing condition on the basis of a wheel speed signal while a decision of a car to be in straight advancing on the basis of a steering angle signal. While the control circuit 15 performs decisions of acceleration and braking by which of the wheels 1-1W1-4 has shown the fastest speed or the slowest speed on the basis of each wheel speed signal. And the control circuit, which performs a predetermined control of an actuator 13 on the basis of these decisions, controls a front wheel differential gear 5, rear wheel differential gear 7 and a center clutch 11. By this constitution, an acceleration quality of the car, its brake characteristic and drivability can be improved. COPYRIGHT: (C)1987,JPO&Japio

Abstract: PURPOSE:To keep a toe angle constant at all times and thereby improve stable operation by variably controlling a car body mounting height of one arm of a parallel link serving to support a rear car wheel vertically rockably with respect to a car body in response to live load or rotation of a steering wheel. CONSTITUTION:A housing 2 for rotatably supporting a car wheel 1 is supported on a car body in its upper part via a strad 3. The housing is furthermore supported on the car body vertically rockably via a parallel link composed of a front arm 4 and a rear arm. Thereupon, a base end part 41 of the front arm 4 is pivoted on a car body member (not shown) via an elastic member, while the base end part 51 of the rear arm 5 is mounted on a guide roller 7 inserted into a circular arc-shaped guide hole 6 formed in a guide member 6 integral with the car body member via an elastic material. A lower end of a coupling rod 8 is mounted on the guide roller 7, and the coupling rod 8 is made elevatable with the aid of an actuator 9 via a crank mechanism for keeping a to angle constant.

Abstract: PURPOSE: To enable the easy and simultaneous execution of checking of the individual states of arrangement of front and rear wheels in relation to the center lines of a vehicle width and of measurement of toe in a servicing factory, by constructing a toe-in gage of a lateral bar member, a longitudinal bar member, a write engagement member and a toe measuring scale member. CONSTITUTION: A longitudinal bar member 11 whose vertical length has been adjusted in accordance with the diameter of a tire T is hing down on the tire, and a lateral bar member 21 whose horizontal length has been adjusted in accordance with the diameter of a wheel is made to touch the outer end part of a wheel rim WR. A toe-in gage 10 is fitted on all of four wheels of the front and the rear in this way, and a wire engagement member 31 is moved in the right and left direction for positioning in accordance with a front wheel tread and a rear wheel tread. When a wire 51 is set on the engagement member 31 and stretched around a vehicle, a wire line lstretched in the horizontal direction between the front and rear wheels is put in a parallel state to the center line of a vehicle width. Therefore, by reading the scale of a toe-in measuring scale member 41 on the basis of said wire lines l, checking of the individual states of arrangement of the four wheels in relation to the center line of the vehicle width and measurement of toe-in can be executed simultaneously. COPYRIGHT: (C)1988,JPO&Japio

Abstract: An actuator for steering the rear wheels in front and rear steering device for a vehicle in which the steering angle of the rear wheels can be manually neutralized should the actuator fail with the rear wheels steered to a certain angle. The actuator may be a type which either directly steers the rear wheels following command from control means or varies the state of means for setting up the steering angle ratio of the rear wheels. In either case, a preferably detachable handle may be engaged to an output end of power means of the actuator. Thus, the situation in which the rear wheels are frozen at a certain steering angle and the driving of the vehicle becomes difficult is safely avoided.

Abstract: The road vehicle train (2) consists of a front vehicle (3) with steerable front wheels (8, 9), a rear axle (10) and a coupling (13) and a rear vehicle (4) which is towed or pushed via the latter and has an axle (27) which is steerable via a drawbar (34) and on which wheels (28, 29) which can be braked individually by means of wheel brakes (30, 31) are mounted. The road vehicle train (2) has a first steering angle sensor (15) which is coupled to the front wheels (8, 9) of the front vehicle (3), a second steering angle sensor (25) for measuring the steering angle of the axle (27) of the rear vehicle (4) in relation to the rear axle (10) of the front vehicle (3) and a steering controller (14) which is active during backwards travel and controls the wheel brakes (30, 31) as a function of steering angles (A), measured by means of the first steering angle sensor (15), in such a way that the axle (27) of the rear vehicle (4) moves into an alignment with relation to the rear axle (10) of the front vehicle, which corresponds to the alignment during forward travel with the same steering angle (A).

Abstract: In a four wheel drive vehicle having a central power distribution device for transmitting engine power to a combination of left and right front wheels and a combination of left and right rear wheels with an action of differentiating rotation between the combination of the left and right front wheels and the combination of the left and right rear wheels, a skidding control device locks up the rotation differentiating action of the central power distribution device when at least either a difference between the rotation of the left front wheel and the rotation of the right front wheel or a difference between the mean rotation of the left front wheel and the right front wheel and the rotation of the combination of the left and right rear wheels exceeds a limit value predetermined therefor.