Study Of Control Strategy To Improve The Dynamic Performance Of Stewart Platform

The dynamic performance of Six-DOF platform is most important qualification among the rest. Through studying the control strategy of electro-hydraulics servo system, advance the dynamic performance of Six-DOF platform and lie the foundation of a high- performance simulator.Based on the structural and movement characteristic of Six-DOF platform,the mathmatic model of the platform and the controller were deduced.With the combination of AMESim simulation software ,it provided clearly reliable guarantee for study.PID algorithm,PID with pressure feedback compensation and Robust H∞have been discussed in the paper. PID algorithmis is simple,steady and easy to implement ,but in the control system of Six-DOF platform ,this method can not meet the need of control effect especially under quick movement and be poor in resisting load disturbance.PID with pressure feedback compensation can advance systemic movement flatness and response speed,but also be poor in the ability of resistance to load disturbance.The Robust H∞control method incarnates the good performance in stabilization.From the low speed to the high speed ,the Robust H∞control method can make the sytem quickly response to the input and keep the whole sytem steady,but the Robust control method can not obviously advance the response speed of whole system.To conclude ,using any one control method among three only can not make the dynamic performance of system best.In conclusion,a control strategy of Robust H∞with pressure feedback compensation is put forward. Experiment study is made on the prototype , and the results indicate that , with this control strategy , the response time,movement accuracy and the ability of resistance to load disturbance can be greatly improved.