Apparatus and method for controlling steer-by-wire system

An apparatus for controlling a steer-by-wire system, comprising:

• a reaction torque generator configured to generate reaction torque as a calculated value of steering reaction torque applied to a steering wheel;
• a rack force estimator configured to estimate a rack force applied to a rack bar of a motor-driven motor steering system;
• a speed controller configured to generate a motor torque command value of the motor-driven power steering system;
• a torque adjuster configured to calibrate the motor torque command value and the reaction torque based on the rack force estimation value, and output final active return torque and final reaction torque;
• and
• a target current generator configured to generate a target current for motor control by using the final active return torque and the final reaction torque, inputted from the torque adjuster, and input the generated target current to a motor.

A method for controlling a steer-by-wire system, comprising:

• generating reaction torque as a calculated value of steering reaction torque applied to a steering wheel;
• detecting a driver torque estimation value as an estimated value of driver steering torque, or estimating a rack force applied to a rack bar of a motor-driven power steering system;
• generating a motor torque command value of the motor-driven power steering system;
• calibrating the motor torque command value and the reaction torque based on the driver torque estimation value or the rack force estimation value, and outputting final active return torque and final reaction torque;
• and
• generating a target current for motor control by using the final active return torque and the final reaction torque, and inputting the generated target current to a motor.