Electric power steering system

摘要

There is provided an electric power steering system that makes it possible to improve the driver's steering feel, and that includes a controller that controls driving of a motor. The controller computes a first assist component Ta1* based on a steering torque Th. The controller computes a torque command value Th* based on a basic drive torque Tc that is the sum of the steering torque Th and the first assist component Ta1*, and computes an assist compensation component Tac through feedback control based on the torque command value Th*. The controller computes a steered angle command value θt* based on a value obtained by adding the assist compensation component Tac to the basic drive torque Tc, and computes a second assist component Ta2* through feedback control based on the steered angle command value θt*. The controller controls driving of the motor based on an assist command value Tas* that is the sum of the first assist component Ta1 * and the second assist component Ta2*.