Simulation And Control For Brushless Motor Of Vehicle Active Steering System

With the continuous improvement of people's living standards, the demands for driver comfort, flexibility, and safety is getting higher and higher. Active steering is a newly developed technology for automobiles that realizes an electronically controlled superposition of an angle to the hand steering wheel angle that is prescribed by the driver. The main objective of this paper is the precise position control of the BLDC motor under complicated road conditions.Position and unknown load torque estimation is a sub-objective to BLDC motor positioning application. Several techniques are presented and compared in this work. For a linear case, a full state Luenberger observer and a Kalman filter are designed. And for a non-linear case, an extended Kalman filter is developed. Based on the (extended) Kalman filter estimation for system state and unknown load torque input, the LQ-optimal regulator is used also in this work for optimal control of the BLDC motor. At last, the comparison of simulation results is made. In the first trial, the conventional PID control and LQ+KF optimal control with load torque compensation are compared. The second trial is with the objective to compare the performance of Luenberger observer and Kalman filter for system state and load torque estimation. The Luenberger observer based state-space feedback control and the LQ+KF optimal control with load torque compensation are also compared. The LQ+KF optimal control strategy has dominant advantages comparing with the other control strategies used in this work.