重型液压机执行器自适应滑模容错控制

Adaptive sliding mode fault-tolerant control of actuator for heavy-duty hydraulic press

为了提高重型液压机在执行器故障情况下的容错控制能力和控制精度,设计了自适应滑模容错控制器。建立了5缸液压机的滑块动力学模型和液压缸压力动态方程。使用积分滑模控制设计了3个子系统虚拟控制律;使用伪逆法实现了控制分配;在执行器故障情况下,在积分滑模控制基础上,提出了自适应补偿策略,从而给出了执行器故障情况下可以实现的虚拟控制律;使用分散滑模控制将虚拟控制律转化为伺服阀控制律,并证明了自适应滑模容错控制器具有Lyapunov意义下的稳定性。经仿真验证,在单个执行器故障或多个执行器故障的情况下,自适应滑模容错控制器能够将调平误差控制在2×10^-4rad内,位移跟踪误差最大为0.0111 m,体现了执行器故障情况下极高的调平和跟踪精度,也体现了自适应滑模容错控制器具有很好的鲁棒性。

To improve fault-tolerant control ability and control accuracy of heavy-duty hydraulic press under the condition of actuator fault,the adaptive sliding mode fault-tolerant controller was designed.Kinetic model of sliding block and pressure dynamic equation of hydraulic cylinder for five-cylinder hydraulic press were built.The virtual control laws of three sub-systems were designed by integral sliding mode control.The pseudo inverse method was used to realize control allocation.Under the condition of actuator fault,adaptive compensate strategy was proposed on the basis of integral sliding mode control,so that the executable virtual control law under the condition of actuator fault was given.The virtual control law was transferred to servo-valve control law by decentralized sliding mode control,and the adaptive sliding mode fault-tolerant controller was proved to possess Lyapunov stability.It was clarified by simulation,under the condition of single actuator fault or multi-actuator fault,the adaptive sliding mode fault-tolerant controller can control the levelling error within 2×10^-4 rad,and the maximum displacement tracking error is 0.0111 m,which reflect high leveling and tacking accuracy under the condition of actuator fault.Besides,it reflects good robustness of adaptive sliding mode fault-tolerant controller.