摘  要：针对交流伺服系统存在的参数变化和外部扰动问题，该文将直接自适应方法与传统滑模控制相结合，提出一套系统化的直接自适应滑模控制策略；利用在线参数估计和开关控制分别实现对未知参数及外扰高频分量的鲁棒性，有效削弱了振颤，实现了较好的稳态性能。将该策略推广至汇总外扰高频分量边界未知的情况，提出一种基于双层嵌套修正的改进型边界估计方法，解决了现有方法中普遍存在的边界估计值恒增问题。结合Lyapunov理论，对所设计控制策略的稳定性进行了全面分析。仿真结果证明了本文所提出方法的有效性。
关键词：直接自适应；滑模控制（SMC）；双层嵌套修正

Abstract: According to parameter variation and extern disturbance in AC servo system, a DASMC strategy based on the combination of direct adaptive method and traditional sliding mode control was proposed in this paper, and robustness against parametric uncertainties and extern disturbance were both achieved via online parameters estimation and switching control, respectively, the chattering was also suppressed effectively. Furthermore, a double nested modification method was proposed for unknown upper bound of high frequency component of the lumped disturbance, to solve the common problem, such as. the estimated bound grows infinity with time. The stability was proved in Lyapunov sense, the simulation results confirm the validity of the proposed method.
Key words: direct adaptive; sliding mode control (SMC); double nested modification