A steering control apparatus determines whether one of an upper variation angle and a lower variation angle is greater than a first threshold value. When one of the upper variation angle and the lower variation angle is greater than the first threshold value, the steering control apparatus determines the state of a clutch in accordance with the result of a comparison between a resulting angle difference variation and a second threshold value. The steering control apparatus updates a reference upper steering angle and a reference lower steering angle such that the reference upper steering angle and the reference lower steering angle respectively correspond to an upper steering angle and a lower steering angle obtained in a predetermined calculation period.

An active suspension system comprises at least one biasing device configured to support a body from a structure, and at least one motor. A magnetorheological (MR) fluid clutch apparatus(es) is coupled to the at least one motor to receive torque from the motor, the MR fluid clutch apparatus controllable to transmit a variable amount of torque. A mechanism is between the at least one MR fluid clutch apparatus and the body to convert the torque received from the at least one MR fluid clutch apparatus into a force on the body. Sensor(s) provide information indicative of a state of the body or structure. A controller receives the information indicative of the state of the body or structure and for outputting a signal to control the at least one MR fluid clutch apparatus in exerting a desired force on the body to control movement of the body according to a desired movement behavior.

The invention is a steering system for use in test driving of an autonomous vehicle, comprisinga manual steering means configured to manually steer the vehicle, a steering axle (30) attached to the manual steering means, anda direct drive motor (35) controllably affecting a torque on the steering axle (30), wherein the direct drive motor (35) has an axis (37) of rotation being coaxial with the steering axle (30). The steering system is characterized in thatit has at least two predefined states characterizing different driving conditions, wherein each predefined state has at least one predefined disengagement limit, andit further comprises a controller assembly operable based on a control parameter, the controller assembly being configured to detect an actual predefined state of the vehicle, and the controller assembly initiates a disengagement of the direct drive motor (35) if, based on a difference value between a prescribed value of the control parameter and an actual value of the control parameter, the at least one predefined disengagement limit corresponding to the actual predefined state is reached. The invention further relates to a disengagement method, and a data processing system, a computer program product and a computer readable medium carrying out the method.

Vehicle steering can be synchronized by first, turning the steering rack from lock-to-lock to determine a steering rack midpoint, second, turning the steering wheel from lock-to-lock to determine a steering wheel midpoint, third, synchronizing the steering rack with the steering wheel based on the steering rack midpoint and the steering wheel midpoint, and fourth, piloting a vehicle based on the synchronized steering rack and steering wheel; wherein the steering rack is mechanically decoupled from a steering wheel of the vehicle before turning the steering rack from lock-to-lock and before turning the steering wheel from lock-to-lock.

A steering apparatus is provided which can suppress unintended movement of a steering wheel when a clutch is engaged. When a power switch is turned off and a steering wheel is steered, a reaction force control circuit makes a reaction force motor to generate a steering reaction force stronger than a normal steering reaction force to give a driver an appropriate feeling of response according to a steering torque. The strong steering reaction force is applied to a steering shaft to suppress steering of the steering wheel. A steering operation control circuit executes steering operation control, that is, control that makes an actual steered angle equal to a target steered angle based on a steering angle, and then a clutch is engaged. The clutch is engaged after confirmation of an immovable state of steered wheels, and thus rotation of the steering wheel unintended by the driver is suppressed.

An independent steering mechanism of controllable hydraulic locking type for left and right wheels is provided. The independent steering mechanism includes a power steering mechanism, a steering drive mechanism, a hydraulic locking mechanism and an electronic control unit. Power of the left and right steering motors flows through the worm, the worm gear, the gear to drive left and right racks to translate. Outer ends of the left and right racks are connected to left and right tie rods via spherical hinges respectively. Inner ends of the left and right racks are connected to a piston rod and a cylinder barrel via spherical hinges respectively. A left chamber and a right chamber in the hydraulic cylinder are connected to an oil reservoir via an electro-hydraulic valve. The left and right steering motor controllers for the left and right steering motor and the electro-hydraulic valve controller are communicated via CAN bus.

A steer by wire steering system for a vehicle includes a reaction force actuator 25, a steering actuator 28, a control unit 40, and a clutch 20, 120 that can selectively connect a steering wheel 11 with road wheels 3 to be steered. The control unit is configured to operate in an emergency mode when a failure is detected while the control unit is operating in a steer by wire mode. The emergency mode includes commanding the clutch to engage, terminating the steer by wire mode, performing a position keep control whereby the steering actuator is driven so as to maintain a fixed steering angle of the road wheels, initiating a power assist mode using the reaction force actuator, and once the clutch is fully engaged, terminating the position keep control.

Vehicle steering can be synchronized by first, turning the steering rack from lock-to-lock to determine a steering rack midpoint, second, turning the steering wheel from lock-to-lock to determine a steering wheel midpoint, third, synchronizing the steering rack with the steering wheel based on the steering rack midpoint and the steering wheel midpoint, and fourth, piloting a vehicle based on the synchronized steering rack and steering wheel; wherein the steering rack is mechanically decoupled from a steering wheel of the vehicle before turning the steering rack from lock-to-lock and before turning the steering wheel from lock-to-lock.

An operation mode of a first actuator engaged with a steering rack is determined. An operation mode of a second actuator engaged with a steering column is determined. The operation mode of one of the first and second actuators is adjusted upon detecting a failure in the other of the first and second actuators. At least one of the steering rack and the steering column is actuated based on the operation mode. In an angle control mode, a predetermined steering angle is provided to the first and second actuators to adjust the steering rack according to the steering angle. In a torque control mode, a steering column torque from a torsion sensor disposed on the steering column is provided to the first and second actuators to adjust the steering rack according to the steering column torque.

A steering control device includes a controller configured to execute turning processing of controlling a controlled variable to a command value corresponding to an operation of a steering wheel by controlling a turning-side actuator in a cutoff state, the controlled variable being at least one of a turning angle of the steered wheels and a turning angle rate that is a changing rate of the turning angle; and transmission switching processing of controlling a switching device such that the switching device is switched from the cutoff state to a transmission state on condition that an absolute value of a difference between the controlled variable and the command value continues to be equal to or larger than a threshold when the turning processing is executed.