交流永磁直线伺服系统的滑模双自由度控制研究

Two degree of freedom control with sliding mode for AC PM linear servo system

针对直接驱动的交流永磁直线伺服系统,提出一种将线性双自由度控制与非线性滑模控制相结合的鲁棒控制策略.内环采用的双自由度控制结构可使扰动得到很大程度的抑制,但还存在余差.外环采用的滑模控制保证了系统的快速跟踪性能,并可以消除内环的余差,使系统具有更强的鲁棒性.同时,双自由度控制中的反馈控制器又能削弱滑模控制的抖振,保证了系统的稳态性能.仿真实验结果表明该方案对系统参数变化和负载扰动具有很强的鲁棒性,

A robust control scheme,based on a combination of linear two -degree of fr eedom control and nonlinear sliding mode control for a ac permanent -magnet linear servo sy stem is presented.The inner loop using two degree of freedom control s tructure can strongly suppress disturbances,but not completely.Then,the disturbance suppression error of th e linear inner loop can be eliminated by the outer loop of sliding mode con-trol,which makes the system more rob ust.Besides,sliding mode control e nsures the system have fast tracking characteristic to the input.At the s ame time,the feedback controller of the two degree of freedom control can effectively minimize the chatterin g of the sliding mode control.Simula tions verify that the proposed contr ol scheme have strong robustness to parameter variations and external disturbances.