Abstract: Operation amounts of actuators are controlled in response to a steering wheel angle .theta.h, a steering wheel angular velocity .theta.hs, and a road surface .mu., in addition to a vehicle speed Vel, to change a caster angle. The caster angle is increased to increase a righting moment of vehicle wheels during steering. The caster angle is increased according to the vehicle speed Vel in non-steering and initial steering conditions, to stabilize the vehicle. This thereby improves the vehicle stability in normal and transitional conditions.

Abstract: In an actuator structure of a vehicle suspension apparatus, an operation rod of an actuator is swingably connected to a vehicle body side end of a lower suspension arm through a rubber bushing, the operation rod is contained in a body and is slidable in a longitudinal direction of the lower suspension arm, and the body is mounted on a vehicle body through a rubber mount, thereby improving durability, environmental resistance, and mounting workability of the actuator structure.

Abstract: A system is for controlling a suspension performance detecting the road surface condition in front of an automotive vehicle. A road surface sensor generates an output corresponding to the size of roughness on a road surface located at a predetermined distance in front of the vehicle. A suspension damping coefficient is changed to a smaller value upon lapse of a delay time. The delay time is calculated on the basis of the output of a speed sensor, the delay time being the time required for the wheel to reach the detected rough roads surface. The changing of the suspension damping coefficient occurs on condition that the output of the road surface sensor falls within a control region defined by a lower threshold value and an upper threshold value.

Abstract: An electronically controlled power steering apparatus for controlling the steering assist amount of a steering mechanism of a vehicle is controlled in accordance with a fatigue condition of a driver of the vehicle. The apparatus includes means for setting an aimed assist amount, and means for detecting a degree of fatigue of a steering operator. The aimed assist amount setting means receives, as an input thereto, a value calculated by the fatigue detecting means and sets the aimed assist amount in accordance with a fuzzy rule so that the steering assist amount may increase as the degree of fatigue steering operator increases.

Abstract: An alignment control unit and method for an automotive suspension are provided in which a basic control amount is determined in accordance with a detected steering angle, and the alignment is controlled in accordance with a product value obtained by multiplying the determined basic control amount by a control gain. The control gain may be set such that an actual control amount of an actuator is changed to be increased when the detected steering angle exceeds a specified value or may be set in accordance with a detected lateral acceleration such that it increases as the lateral acceleration increases. The toe angle or camber angle of a wheel may be controlled in accordance with the basic control amount.

Abstract: A pneumatic active suspension apparatus is provided wherein, when a sprung vertical acceleration (ZG), which causes a wafting phenomenon perceptible by a person in a vehicle, occurs during travel of the vehicle, supply/discharge of air to/from air spring chambers of suspension units is carried out for a supply/discharge control time determined based on the maximum value (ZGmax) of the sprung vertical acceleration. The supply/discharge control is started at an advanced time based on the sprung acceleration whose phase is advanced by 90 degrees from that of the sprung velocity, to thereby produce a force acting to cancel out the sprung vertical velocity at proper timing. As a result, the operation delay of the suspension apparatus is compensated for and the sprung vertical motion is suppressed.

Abstract: A vehicular suspension control apparatus includes a selector valve for changing at least one of spring rigidity or damper rigidity of a suspension which is installed between a wheel and a body of a vehicle and extensibly and retractably supports the vehicle body on the wheel, a forward road surface sensor attached to the vehicle body and adapted to detect an irregularity of a road surface located in front of the vehicle body at a predetermined distance from the mounting position of the sensor when the vehicle body is in a predetermined attitude, a vehicle speed sensor for detecting a vehicle speed, and a controller for calculating a point of time when the wheel reaches the irregularity of the road surface, in accordance with the vehicle speed detected by the vehicle speed sensor, when the irregularity of the road surface is detected by the forward road surface sensor, and delivering a command signal for lowering at least one of the spring rigidity and the damper rigidity of the suspension to the selector valv

Abstract: A rear wheel braking force control apparatus of a vehicle includes a pressure sensor 74 for detecting master cylinder pressure, right and left proportioning valves 57.sub.1 and 57.sub.2 individually disposed in passages for transmitting master cylinder pressure to right and left wheel cylinders of the rear wheels for controlling to decrease changes in wheel cylinder pressure relative to changes in master cylinder pressure, right and left PCV bypass valves 62 and 63 for individually bypassing the proportioning valves, and a controller 71 which, when the vehicle is determined by a steering angle sensor 77 or the like to be turning, closes the PCV bypass valve at the outer wheel side when the master cylinder pressure is higher than the pressure of the PCV bypass valve at the inner wheel side.

Abstract: An active suspension apparatus is provided for a vehicle which includes an actuator being extensible and retractable and provided between a vehicle body and a wheel so that the force of the vehicle body to support the wheel is adjustable, a sprung G sensor or a vehicle height sensor for detecting a vibration input to the vehicle body, and a control valve and a controller for controlling the supporting force of the actuator in accordance with the vibration input detected by the sprung G sensor or the vehicle height sensor, and thereby restraining the stroke of the actuator.

Abstract: When a master cylinder pressure detected by way of a pressure sensor (74) attains a level not lower than a target pressure (P.sub.OK), normally-open on-off valves (62, 63) for by-passing proportioning control valves (57.sub.1, 57.sub.2) are opened. If the slip factor of rear wheels, calculated by way of a slip factor calculation section (121), is not lower than a predetermined value, the on-off valves (64, 66) are opened to allow the rear wheel cylinder pressure to escape to accumulators (65, 67). Thus, if there is enough room for the increase of the braking force on the rear wheels, the rear wheel braking force can be increased to reduce the share of the front wheel braking force, depending on braking conditions, such as the road surface conditions, vehicle running conditions, etc. Further the rear wheels can be prevented from being locked.

Abstract: A first target value is set as an initial value of split point pressure, a master cylinder pressure is set as a second target value of split point pressure in a memory when ABS valves (17, 20, and 23) are operated, thereafter when a sign of locking of the rear wheels is detected, the target value is reduced even further and set in the memory, the target value is maintained for a predetermined time by timer control at every setting of a new target value, and when a braking deceleration generated while the target value is maintained in the memory, a controller (37) controls so that the target value is increased after the completion of braking. When the master cylinder pressure is higher than the target value stored in the memory, proportioning valves (26 and 27) are closed to decrease a ratio of the rear wheel braking force to the front wheel braking force, thereby always achieving appropriate control over the rear wheel braking force allocation.

Abstract: In a turning control apparatus for a vehicle, a torque calculation unit calculates a target lateral acceleration of the vehicle according to detection signals from a steering angle sensor for detecting the direction of a steering wheel and a vehicle speed sensor for detecting the speed of the vehicle. It then sets target driving torque of the engine according to the target lateral acceleration. An electronic control unit controls the operation of a torque control device for reducing driving of the engine so that the driving torque of the engine is a target driving torque independent of manipulation by the driver. This thereby rapidly estimates lateral acceleration applied to the vehicle during turning and prevents control delay to enable stable and positive traveling through a curved road.

Abstract: An actuator is used to drive a transmission ratio changing mechanism, which is arranged between a steering wheel and front wheels of a vehicle, for correcting the turning angle of the front wheels. The operation of the actuator is controlled in accordance with detection signals from sensors for detecting first and second turning actions, and an angular turning angular speed of the steering wheel. A controller delivers a corrective turning control signal for increasing the turning angle of the front wheels to the actuator when it is detected that the steering wheel is in the second turning action and that the value of the angular turning speed for the second turning action is at least equal to a reference value.

Abstract: A four-wheel steering apparatus for a vehicle includes a hydraulic actuator for steering the rear wheels, and first and second oil pumps. An in-phase steering control valve is connected between the first oil pump and the actuator and outputs first hydraulic output for steering the rear wheels in phase with the front wheels in accordance with a steering state of the front wheels. An antiphase steering control valve is connected between the second oil pump and the actuator and outputs second hydraulic output for steering the rear wheels in opposite phase to the front wheels in accordance with a rate of change in the steering state of the front wheels. The hydraulic actuator combines the first and second hydraulic outputs from the control valves and steers the rear wheels in accordance with the difference between the hydraulic outputs.

Abstract: A steering gear ratio changing apparatus includes a first and second steering shafts arranged to be coaxial with each other. The first steering shaft is coupled to a steering wheel of a vehicle and rotatable integral therewith. The second steering shaft is coupled to a steering gear mechanism and arranged to be rotatable. First pawls are formed on one end of the first steering shaft and arranged at equal intervals along the circumferential direction of the shaft. Second pawls are formed on one end of the second steering shaft, which oppose the end of the first steering shaft, and are arranged at equal intervals along the circumferential direction of the shaft. The first and second steering shafts are coupled with each other by a torsion bar and held thereby so that the first and second pawls are engage with one another with a gap between any two adjacent first and second pawls. The width of the gaps is adjusted by actuators so as to cause a relative rotation between the first and second steering shafts.

Abstract: A suspension control apparatus for an automotive vehicle has a plurality of suspension units which are disposed between each of the wheels of the vehicle and the vehicle body. A plurality of actuators for controlling the characteristics of the suspension units are controlled by a control unit in response to the output of an acceleration sensor. The ground circuit of the acceleration sensor is connected to the ground circuit of the control unit.

Abstract: Disclosed is a control apparatus for a vehicular suspension system having a plurality of suspension units each disposed between a road wheel and the body of a vehicle for suspending the corresponding road wheel from the vehicle body. The control apparatus includes a control unit which is connected to receive the output signals from an acceleration sensor, a vehicle-speed sensor and a steering sensor for calculating the rolling state of the vehicle due to a transverse acceleration thereof and controlling the respective suspension units based on the calculated rolling state of the vehicle so as to suppress the rolling thereof.

Abstract: A suspension control apparatus and a method for a vehicle having a plurality of suspension units each disposed between a road wheel and the body of a vehicle for suspending the corresponding road wheel from the vehicle body. The suspension control apparatus includes a control unit which is connected to receive the output signals from an acceleration sensor, a vehicle-speed sensor and a steering sensor for calculating the rolling state of the vehicle due to a transverse acceleration thereof and controlling the respective suspension units based on the calculated rolling state of the vehicle so as to suppress the rolling thereof. The control unit serves to determine the period or frequency of change or reversal of the direction of the detected transverse acceleration of the vehicle, and control the suspension units so as to stop the roll-suppression control when the frequency of reversal exceeds a prescribed level.

Abstract: Disclosed is a suspension control apparatus for a vehicle having a plurality of suspension units each disposed between a road wheel and the body of a vehicle for effectively and quickly correcting any deviation of the vehicle height from a normal height level immediately upon finishing of active suspension control operations. Priority is determined for vehicle-height control and various active suspension control operations such as roll control, nose-dive and squat control, and pitching and bouncing control so that normal vehicle-height control is stopped or inhibited during active suspension control operations are being carried out, thereby preventing the traveling attitude of the vehicle from being made unstable.

Abstract: A flow control valve includes a cylinder in which an inflow port, an outflow port and a return port are formed. A spiral choke is formed between the inflow and outflow ports. A working oil introduced from the inflow port into the cylinder flows out from the outflow port through the spiral choke. An actuating valve is arranged in the cylinder so as to open and close the return port in accordance with a difference in pressure between the inflow and outflow port sides of the spiral choke. When the pressure difference exceeds a predetermined value, the actuating valve opens the return port so that a part of the working oil introduced into the cylinder is returned to the inflow side of the flow control valve.