Steering control device

A steering control device configured to control a steering system including a housing, a steered shaft housed in the housing so as to reciprocate, and an actuator that applies motor torque for causing the steered shaft to reciprocate using a motor as a drive source, the steering control device comprising

• an electronic control unit configured to
• detect an absolute steering angle which is a rotational angle of a rotary shaft that is convertible into a steered angle of steered wheels coupled to the steered shaft, and which is indicated by an absolute angle in a range including a range exceeding 360°,
• compute a current command value corresponding to a target value for the motor torque output from the motor, and
• control driving of the motor such that an actual current value supplied to the motor matches the current command value, wherein:
• the electronic control unit stores an end position corresponding angle that indicates an end position at which movement of the steered shaft is restricted by an end strike in which the steered shaft contacts the housing, the end position corresponding angle being related to the absolute steering angle;
• the electronic control unit is configured to execute end strike relaxation control for correcting the current command value, in a case where an end separation angle is equal to or smaller than a predetermined angle, such that a decrease in the end separation angle is restricted, the end separation angle indicating a separation of the absolute steering angle from the end position corresponding angle;
• the electronic control unit is configured to execute partial release control for reducing a correction amount for the current command value determined through execution of the end strike relaxation control in a case where turning of a vehicle is attempted during the execution of the end strike relaxation control;
• the electronic control unit is configured to make a non-following determination as to whether the movement of the steered shaft is restricted during execution of the partial release control, based on a degree to which an angular velocity of the motor follows a target angular velocity, and acquire a release-time restriction position determination angle that corresponds to the absolute steering angle detected at a time when the electronic control unit determines that the movement of the steered shaft is restricted;
• and
• the electronic control unit is configured to permit update of the end position corresponding angle based on the release-time restriction position determination angle, and update the end position corresponding angle in a case where the update of the end position corresponding angle is permitted.