中文摘要：

针对高精确度五轴联动数控机床中主轴头复合A／C轴直接驱动永磁环形力矩电机伺服系统易受负载扰动和参数变化影响的特点，设计了二阶滑模速度控制器。二阶滑模控制算法具有一阶滑模控制算法的鲁棒性和动态性能，并能消除一阶滑模控制存在的抖振现象。采用二阶滑模超螺旋算法对系统进行控制，以增强伺服系统的鲁棒性并消除抖振。仿真结果表明，所提出的策略使伺服系统具有很强的速度跟踪性能，并且对负载扰动和参数变化等不确定性具有很强的鲁棒性，同时消除了抖振现象。

英文摘要：

For the characteristics of compound A/C axe direct drive permanent magnet nng torque motor servo system in high precision five axes module numerical control machine being influenced by varying of load and variables, the second order sliding mode speed controller is proposed. The second order sliding mode control algorithm had robustness and the dynamic performance of traditional sliding mode control algo- rithm（control algorithm of first order sliding mode）, and eliminated the chattering phenomenon. In order to strengthen robustness and eliminate chattering, the system was controlled by the super twisting algorithm of the second order sliding mode control. The results of simulation show that the designed method enables servo system to have strong speed-tracking performance, and have very strong robustness against load disturbances, parameters varieties and other uncertainties, and the chattering phenomenon is eliminated.