Abstract
A new column type electric power steering system (EPS-TT) is proposed in this study. The remarkable features of EPS-TT are its opto-isolated torque sensor and assist torque control methodology. EPS-TT uses a uni-directional motor and two clutches. Full order and simplified models for EPS-TT are developed to evaluate the EPS-TT. A full car model is also used to investigate the vehicle responses. A PID control logic is designed to control the torque of the assist motor. Various sinusoidal inputs are applied to the system and the resulting performances are analyzed. The results prove that the performances achieved by the EPS-TT are improved compared to those of a conventional EPS-TT across the frequency domain. In addition, it is inexpensive and easy to control the motor. The results of the full order steering system model are similar to those simplified model, but the vehicle responses are slightly different.