Research And Design Of Column-assist Type EPS Controller Based On PMSM With Magnetoresistive Rotor Position Sensor

Compared with other power steering system, Electric power steering system (EPS) has the advantages of saving energy, compact structure, easily mounting.EPS which can improve the control stability of vehicle provides the technological base for Driving Assist system such as automatic parking, active obstacle avoidance etc. Permanent Magnet Synchronous Motor (PMSM) has the character of high power density, simple structure, low torque ripple and long service life,which meets the requirement for motor of electric power steering system. Therefor Field Oriented Control (FOC) of PMSM. is analyzed. In order to solve the problem of rotor position sampling, the principle of magnetoresistive position sensor is researched. In this dissertation, an EPS controller is designed by using a PMSM which rotor position is detected by magnetoresistive rotor position sensor.The mathematic of PMSM is decoupled by the method of coordinate transformation. The torque of PMSM is controlled based on the control method of FOC. Then the technology of space vector pulse width modulation (SVPWM) is introduced detailedly.The target of this dissertation is to design an EPS controller, based on the analysis of EPS control strategy, Hardware and software are designed to achieve the function, bench test are made to let program code conform to the electric power steering.Finally, the steering handiness and return to center performance are verified by real vehicle tests.