基于扰动观测器的电液比例系统滑模位置控制

针对电液比例阀控缸驱动的并联机构,设计一种基于扰动观测器的滑模控制方法。在对并联机构末端执行器进行位置控制中,因末端执行器受到被试件转动产生的扰动,且并联机构支链相互耦合,支链液压缸实际负载与理论负载存在较大误差,且误差很难计算出。为此设计非线性扰动观测器以估计未知负载力,在滑模控制器中进行负载扰动补偿。使用滑模控制增强系统的鲁棒性。仿真结果表明:所设计的扰动观测器具有很好的观测效果,在扰动负载的干扰下,该控制系统可实现精确的位置控制,对未知非线性扰动系统具有很好的鲁棒性。

Sliding Model Position Control Based on Disturbance Observer for Electro-Hydraulic Proportional Systems

A sliding model controller based on disturbance observer(DOB)is designed for parallel actuator driven by electro-hydraulic proportional valve-control cylinders.In the position control of the parallel mechanism,due to the disturbance caused by the rotation of workpiece,and the coupling of the branches of the parallel mechanism,the theoretical load have a large error with the actual load of the hydraulic cylinder,and the error is difficult to be calculated.In the study,the nonlinear disturbance observer is designed on the basis of system dynamics model in order to estimate the unknown load,and compensate the load force in the sliding model controller,which improves the robust of the control systems.The simulation results show that the disturbance observer has a good effect,and the designed controller under the disturbance of load disturbance can realize accurate position control and has strong robust.