中文摘要：

由于永磁同步电动机位置跟踪系统存在参数摄动和外部扰动等非线性问题，影响系统的稳定性。为解决上述问题，提出一种基于转矩观测器的反步滑模变结构控制策略．提高了系统的响应速度和抗外界扰动的能力。首先在反步控制器设计过程中引入滑模项，提高了系统的鲁棒性。然后利用负载转矩观测器实时估计负载转矩，把转矩估计值作为前馈电流补偿，抑制负载突变带来的影响，提高系统抗负载扰动的能力，同时减少了控制输出的“抖振”现象。理论分析及仿真结果验证了所提出控制策略可有效地提高系统的稳定性。

英文摘要：

A nonlinear position controller based on backstepping technique with sliding mode control is addressed for permanent magnet synchronous motor （PMSM） position tracking system with unknown parameters and load torque and other uncertainties. The method enhances the quick response and anti-disturbance ability of the control system. The sliding mode control is applied to the backstepping control to improve the robust performance of the system. A load torque observer is used to estimate load torque in real time to be the feed forward current compensation. The in- fluence on the performance of control system caused by load torque disturbance can be inhibited. Mean＇shile, the chattering phenomenon is reduced. Theoretical analysis and Matlab simulation results show the effectiveness of the proposed method.