A turning mechanism is equipped with a wire (first movable member) which moves in a movable direction (direction of the arrow B) under the motive power of a turning actuator, a wire (second movable member) which moves in a movable direction under the motive power of a turning actuator, and a coupler connecting the two wires. The coupler is configured in a manner so that the wires are capable of being moved independently in the case that a difference (differential angle) between the toe angles of the rear wheels lies within an allowable range, whereas in the case that the differential angle has exceeded the allowable range, is configured in a manner so that the wires are capable of being operated in a mutually interlocked manner.

A method of operating a vehicle to maintain the vehicle along a desired course. The vehicle has a first steering system for turning left and right wheels at a first end of the vehicle, a second steering system for turning left and right wheels at a second end of the vehicle, brakes for slowing rotation of the wheels, and a steering lock mechanism. The method includes determining that the first steering system is malfunctioning. The steering lock mechanism is operated to lock out turning of the left and right wheels at the first end of the vehicle. The brakes are operated to maintain the vehicle along the desired course. The second steering system is operated to maintain the vehicle along the desired course.

A control system of a wheel of a vehicle includes: a wheel speed sensor configured to measure a wheel speed of wheels of the vehicle; a data storage configured to store data relating to a plurality of abnormal patterns based on a slip state or a lock state of each wheel; and a controller configured to extract wheel speed pattern data using wheel speeds measured from the wheel speed sensor, to compare the extracted wheel speed pattern data with the stored data relating to the plurality of abnormal patterns, to determine an abnormal pattern among the plurality of abnormal patterns most similar to the extracted wheel speed pattern data according to the comparison, and to detect an abnormal wheel among the wheels of the vehicle based on the determined abnormal pattern.

A lock mechanism is provided in an actuator capable of changing a toe angle of a wheel by rotational drive of a motor and adapted to lock operation of the actuator when the rotational drive of the motor is stopped. The lock mechanism includes a casing secured to a housing of the actuator, an input-side shaft connected to a motor shaft of the motor and rotatably held in the casing, an output-side shaft to which rotational torque is transmitted from the input-side shaft, and an engaging part. The engaging part includes a pair of friction members displaceably provided along a guide groove, a claw part having an acute shape in cross section and a side end part which are provided on the input-side shaft, an abutting part provided on each friction member, and a coil spring for urging each friction member.

A hydraulic unit for supplying pressure to a hydraulic steering system is provided having at least two hydraulic cylinders and at least one hydraulic pump (9, 10, 32, 33). It is essential that the hydraulic cylinders are of interacting configuration, by an annular space (6a, 6a, 28a, 28b) of the first hydraulic cylinder being connected via at least one hydraulic line to an annular space (6a, 6a, 28a, 28b) of the second hydraulic cylinder, and a piston space (5a, 5b, 29a, 29b) of the first hydraulic cylinder being connected via at least one hydraulic line to a piston space (5a, 5b, 29a, 29b) of the second hydraulic cylinder, and a hydraulic pump (9, 10, 32, 33) being arranged at least in a hydraulic line (7, 8, 30, 31) between the two annular spaces (6a, 6a, 28a, 28b) or in a hydraulic line (7, 8, 30, 31) between the two piston spaces (5a, 5b, 29a, 29b). Furthermore, the invention relates to methods for operating a hydraulic unit for supplying pressure to a hydraulic steering system, and to a steering system.

The present disclosure relates to a rear-wheel steering system and a controlling method thereof. The rear-wheel steering system includes: a rack configured to transmit a driving force generated from a rear-wheel steering motor to rear wheels; a first correction module configured to, when an engine is started, detect a position of the rack using a displacement sensor and calculate a first correction value that is a difference between the detected position and a neutral position; a second correction module configured to, when the engine is started, detect a position of the rack using a motor position sensor that detects a rotation angle of the rear-wheel steering motor and calculate a second correction value that is a difference between the detected position and the neutral position; a comparison determiner configured to compare the first correction value and the second correction value to determine whether the displacement sensor has malfunctioned; and a steering controller configured to control an operation of the rear-wheel steering motor. Accordingly, it is possible to determine whether an error occurs in the displacement sensor and to return the rack to the neutral position even when the error has occurred in the displacement sensor.

A control apparatus for a rear wheel steering system is provided to control the rear wheel steering system by calculating a target rear wheel steering angle using sensors included in a parking assist system. The control apparatus includes a first sensor and a second sensor spaced apart from each other and mounted on a rear portion of a vehicle, a determiner configured to determine whether a trailer is mounted at a rear side of the vehicle using the first sensor or the second sensor, and a controller configured to control the rear wheel steering system according to a target rear wheel steering angle calculated using the first and second sensors when it is determined that the trailer is mounted at the rear side of the vehicle.

A method for controlling rear wheel steering of a vehicle may include: determining, by a control unit, whether an error exists in rear wheel steering control input information received therein to control rear wheel steering of the vehicle; calculating, by the control unit, a rear wheel angle reduction rate for controlling rear wheels to neutral based on a yaw rate of the vehicle when it is determined that an error exists in the rear wheel steering control input information; and controlling, by the control unit, the rear wheels to neutral according to the calculated rear wheel angle reduction rate.

A lock system can be provided at each rear wheel assembly of a four wheel steering system to physically lock the rear wheel assemblies in a fixed direction to safely prevent rear wheel steering when such feature is undesirable. The lock system can use an electronically controlled actuator to hydraulically drive or retract a lock cylinder to lock or unlock the rear wheel assemblies, respectively. Sensors can be used to detect whether the lock cylinders are driven or retracted by their respective actuators, so that a controller monitoring the sensors can determine whether four wheel steering is enabled or disabled.

An apparatus and a method for controlling a rear wheel steering (RWS) system, may include determining, by a controller, whether an abnormality occurs in a rear wheel alignment based on information collected from the vehicle; determining, by the controller, a correction amount of the rear wheel alignment for correcting the abnormality occurring in the rear wheel alignment using predetermined data based on one or more of the information collected from the vehicle when the abnormality is determined to occur in the rear wheel alignment; correcting, by the controller, a rear wheel control position determined based on variable information related to an RWS control using the determined correction amount of the rear wheel alignment; and controlling, by the controller, an RWS actuator of the vehicle based on the corrected rear wheel control position, and an apparatus for controlling an RWS system.