A steering control device according to the present invention has an electromagnetic clutch (34) built into an electric motor (14B). The electromagnetic clutch (34) is provided with: an armature (61) connected to a first closing member (33) via a guide member (68), a coil holding part (59), and a bolt (65); a clutch plate (62) connected to a rotor (31) via a clutch plate attachment member (64), a key (69), and a motor shaft (32); and an excitation coil (60) held by the coil holding part (59). The armature (61) is fastened with the clutch plate (62) when not attracted to the excitation coil (60) during a power supply failure of the electric motor (14B), and regulates relative rotation of the rotor (31) with respect to a motor housing (29), Steering of a rack bar (10B) is thereby restricted at an optional steering position via the motor shaft (32), a worm shaft (25), and a steering shaft (8B).

Disclosed examples include setting a coupling resistance between a road wheel actuator and a steerable road wheel of a vehicle at a first time by controlling an electrical damping device to increase an electrical resistance of an electric motor of the road wheel actuator; and changing the coupling resistance between the road wheel actuator and the steerable road wheel at a second time by controlling the electrical damping device to further increase the electrical resistance of the electric motor of the road wheel actuator.

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.

A steer by wire type steering apparatus according to the present embodiments comprises a rotating shaft that rotates in conjunction with a steering shaft, a housing provided with a ball seating portion at one end and a ball is coupled and supported between the ball seating portion and an inner circumferential surface of the rotating shaft, a support member disposed inside the housing and provided with a protruding support portion for supporting the ball to one side in a circumferential direction while protruding in an axial direction, a ball support elastic member coupled to the housing and elastically supporting the ball to another side in the circumferential direction, and an actuator for moving the support member in the axial direction.