Research On Trajectory Tracking Control Of Electro-hydraulic Servo Planar Parallel Mechanism

In this paper,the electro-hydraulic servo joint dual-drive planar parallel three-degree-of-freedom mechanism is taken as the research object.Through theoretical research,simulation analysis and experiment,the trajectory tracking control strategy of the object is discussed under the condition of considering the uncertain disturbance of the system,to provide a theoretical basis for the further implementation and improvement of the project.The main research contents are as follows:(1)Kinematics modeling was carried out for the research object,including forward/ inverse kinematics analysis,speed analysis,acceleration analysis;dynamics modeling was used for load simulation;in order to improve the accuracy of kinematics control,a kinematics model-based Theoretical research on structural parameter calibration,simulation and experiments show that this method can effectively improve the kinematic accuracy of the system.(2)The nonlinear state equation of the electro-hydraulic servo system is established,and the control structure based on the joint space is adopted.For the uncertainty interference problem existing in the system,a sliding mode controller based on the nonlinear interference observer is designed.The linear disturbance observer observes the time-varying external disturbance force of the unknown upper bound to perform control compensation,and the sliding mode control is used to suppress bounded disturbances such as parameter uncertainty,unmodeled parts,and observer observation errors to achieve high system accuracy.Highly robust control.The simulation shows that the proposed control strategy has high tracking control accuracy and strong anti-interference ability,the control experiment proves that the control strategy has high control precision.(3)A collaborative control strategy based on joint coupling error is proposed.The basic control structure is still based on the joint space control of the nonlinear disturbance observer.First,the sliding mode control in the previous chapter is replaced by combining sliding mode control and cascade control to reduce the order of the controller;secondly,it is based on the joint The problems of intra-group synchronization and inter-group cooperative control cannot be achieved between individual controllers in space.On the basis of the previous step,the concepts of intra-group synchronization error and inter-group cooperative error are introduced,and a comprehensive joint tracking is defined.The joint coupling error of error,inter-group coordination error and intra-group synchronization error is used as the feedback signal of the controller,so that the system can perform synchronous cooperative control while tracking control.Simulation shows that the proposed control strategy has higher tracking performance and anti-interference performance,and can also improve the system’s intra-group synchronization performance and inter-group coordination performance,and these two performances also have anti-interference ability,the control experiment shows that the control strategy can improve the synchronization and coordination of the system.