Dynamic Coupling Characteristic Analysis of a Loaded Stewart Parallel Robot

The Stewart parallel robot always works with load and the load will cause dynamic coupling among different degree-of-freedoms, which seriously affects the accuracy of the system. In order to improve the accuracy and suppress the dynamic coupling, it is necessary to analyze the coupling characteristics of system dynamics. Aiming at the problem of dynamic coupling, this paper firstly established a dynamic modeling of the Stewart parallel robot with load, and then the dynamical coupling characteristics among the six degrees under the influence of the load are analyzed theoretically, and the reasons of the dynamic coupling and the distribution of dynamic coupling among six degrees are determined. Finally, a simulation was carried out in Simulink. The simulation results show that the dynamic coupling of the system is mainly caused by the load, and there are three types of dynamic coupling, and the dynamic coupling will change as the robot posture changes. The simulation results agree well with the theoretical analysis. Therefore, the research result in this paper can be used for the design of dynamic decoupling control strategy and system parameter identification algorithm.