Modelling and simulation of electric power steering system using permanent magnet synchronous motor

Abstract

This paper presents a control technique for Electric Power Steering System (EPS) using Permanent Magnet Synchronous motor (PMSM) for steering application. The EPS model is developed using the mathematical equations; mechanical subsystem of steering unit is modelled using the dynamic equations of steering unit. The objective of EPS system is to provide the assist torque to the steering wheel to drive the vehicle, here PMSM provides the additional assist torque along with the driver input to steer the vehicle. The control logic implemented here considers the input torque from steering wheel and vehicle speed. Depending upon these two inputs, the q-axis current component required for the PMSM motor to provide the additional assist torque is computed. The complete EPS system is modelled in Matlab/Simulink and simulated for different driving inputs.