摘要：针对伺服电机速度控制系统的性能要求，提出一种基于扰动估计和目标给定补偿的控制方案。通过设计降阶观测器对未知扰动进行估计和补偿，消除扰动带来的稳态速度跟踪误差；根据设定点的跳变对观测器变量进行重置，使控制信号保持平滑，有利于系统的安全运行。采用2阶Lagrange插值多项式来逼近电机位置轨迹，进而计算出电机瞬时转速。此控制方案被用于直流伺服电机的速度调节，并在TMS320F2808 DSP上进行了实验验证。将此方案并与常规PI控制进行比较, 结果表明，设计的控制方案可以为伺服系统性能带来显著的改进，即能在较大的转速范围内实现快速、平稳和无静差的伺服跟踪，并具有较好的鲁棒性。所提出的控制方案，可推广应用到其他伺服系统。

关键词：伺服系统；瞬态性能；扰动；观测器；拉格朗日插值
Abstract: To meet the performance specification in servo motor speed control systems, a new control scheme was proposed, which was based on disturbance estimation and setpoint compensation (DESC). In the control scheme, a reducedorder observer was designed to estimate the unknown disturbance in the servo system and then used for compensation, so as to remove the steadystate speed tracking error. The state variable of the observer was reset whenever there was a rapid change of setpoint, to ensure the smoothness of control signal and thus the safe operation of the control system. A 2ndorder Lagrange interpolation polynomial was adopted to approximate the position trajectory of servo motor, from which the instantaneous motor speed could be obtained by taking its derivative. The control scheme was then applied to a DC servo motor system for speed control, and experimental tests had been conducted using the TMS320F2808 DSP board. Comparisons were made with the conventional PI control. The results verify that the control scheme can bring a significant improvement to the servo system, i.e., the system is capable of fast, smooth and accurate servo tracking a wide range of target speed, with a strong robustness. This design can be generalized to other servo systems.

Key words: servo system; transient performance; disturbance; observer; lagrange interpolation