Loading test system of orthogonal parallel multidegreeoffreedom

WANG Bo, HUANG Qitao

(School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China)

Abstract: Aiming at the traditional loading system lacked the ability to provide mutiaxis forces and torques which was needed in the fatigue test of space docking mechanism, an orthogonal six degrees of freedom(6DOF) parallel loading system was presented, and the configuration, dynamics and control strategy of the system was studied. The dynamics of static loading and dynamic loading was built using NewtonEular method. Based on it, the Simulink model about inverse solution of dynamics was built, which could transform generalized force into actuator force. Then the PID control combined with dynamic pressure feedback was used to achieve the control requirements. In order to avoid the use of 6DOF force sensor, which would bring high costs, the control strategy of the system was built based on actuator force closedloop. Experimental results indicate that the system loading error is less than 1%, which can provide an accurate data for the fatigue and reliability test of the mechanism.

Key words: parallel robot; MutiDOF loading system; force control strategy