Abstract: The rigid body dynamic model of the parallel kinematic machine (PKM) is complicated and difficult to be used in the real-time control system. Under the accelerated motion and the decelerated motion, a study on the simplification of the rigid body dynamic model for a 6-UPS PKM is presented. Firstly, the dynamic model is established through Newton-Euler approach and decomposed into eighteen items. According to the working situation, the rigid body dynamic characteristics of the PKM are investigated by the means of numerical simulation. Finally, the simplifying strategies of the dynamic model are presented and verified. It is proved by the verification results that the strate-gies improve the computational efficiency greatly and only bring small simplifying errors.

Key words: Parallel kinematic machine, Rigid body dynamic characteristic, Rigid body dynamic model, Simplifying strategy