中文摘要：

设计了一种新颖的基于改进的2阶离散平滑滤波器无刷直流电动机位置伺服控制系统。2阶离散平滑滤波器的输出适合于伺服系统，特别是2阶系统的前馈控制，能保证系统的最小时间响应和平滑轨迹跟踪。在将无刷直流电动机等效为2阶系统的基础上，整个控制系统的外环采用2阶离散滤波器控制，内环为电流PI控制器，实现无刷直流电动机的级联位置伺服控制。因此，该系统兼具线性控制和非线性控制的优点。通过负载转矩观测器的设计，提高了电动机在内部参数变化和外部负载扰动下系统的抗干扰能力。该控制方法不但能实现系统位置的良好跟踪还能保证速度的及时响应，仿真与实验结果证明了该控制策略的有效性。

英文摘要：

A novel position servo controller for a brushless DC motor was designed based on the improved second discrete smooth trajectory filter. The output of the filter is suitable for the feed-forward control for the servo system, especially for the second order system, which guarantees minimum time response and smooth trajectory tracking. Based on the second order model of the Brushless DC motor, the cascade servo control of the brushless DC motor was implemented upon the second discrete filter algorithm. The outer-loop of the whole control system was realized by the second discrete filter, and the inner-loop used the traditional PI current controller. It has the integrative merits of linear and nonlinear control methods. Moreover, a load torque observer was advanced to enhance the anti-disturb ability of the servo system when the brushless DC motor running with the motor parameters change and/or external load variation. The proposed control method can obtain the excellent position tracking performance and a good speed response ability. Simulation and experiment results show that the control scheme is valid and effective.