直接驱动数控转台自适应二阶滑模控制

Adaptive second order sliding mode control for direct drive NC rotary table

针对直接驱动数控转台用环形永磁力矩电动机易受负载扰动及自身参数变化影响的特点,设计了自适应二阶滑模控制器。控制律采用自适应螺旋算法,二阶滑模将不连续控制作用于变量的高阶微分上,削弱了抖振现象。引入自适应控制是对螺旋算法中的控制增益进行动态调节,从而克服了控制增益需要不确定性的界来确定的局限,进而提高了控制性能。仿真结果表明该策略具有较强的位置定位能力,对负载扰动和参数变化等不确定性具有很强的鲁棒性,同时有效地削弱了抖振现象。

For the characteristics of the ring permanent magnet torque motor used in direct drive numerical control( NC) rotary table suffering from the effect of load disturbances and parameters variations,the adaptive second order sliding mode controller is designed. Control law is achieved by adaptive twisting algorithm. The discontinuous control effects on the higher differential,and eliminate the chattering phenomenon. The introduction of the adaptive control is the control gain of the twisting control law with dynamic adjustment,thereby to overcome dependence of control gain required to determine the boundaries of the uncertainty,and then improve the control performance. Simulation results show that the designed strategy enables servo system to have strong position location performance,and to have very strong robustness against load disturbances and parameters variations,simultaneously attenuates chattering effectively.