Steering control device

A steering control device configured to control a steering system that has a structure in which a power transmission path between a steering unit that is connected to a steering wheel and a turning unit that turns turning wheels by an operation of a turning shaft according to steering input to the steering unit is cut off, the steering system having a function of changing a steering angle ratio which is a ratio of an amount of rotation of the turning wheels to an amount of rotation of the steering wheel, the steering control device comprising:

• a control unit configured to control at least an operation of a steering-side motor which is provided in the steering unit such that a steering reaction force which is a force against the steering input to the steering unit is generated,
• wherein the control unit is configured to:
• calculate a target reaction torque which is a target value of a motor torque of the steering-side motor, the motor torque serving as the steering reaction force;
• calculate a difference axial force that is used to limit steering for turning the turning wheels in a predetermined direction, the difference axial force being reflected in the target reaction torque;
• and
• set a reference angle to one of a steering angle which is set as a value indicating the amount of rotation of the steering wheel and a turning angle which is set as a value indicating the amount of rotation of the turning wheels, set a converted angle to an angle which is obtained by converting another of the steering angle and the turning angle according to the steering angle ratio, and calculate the difference axial force based on a difference between the reference angle and the converted angle.