Dynamic Modeling of Parallel Mechanism Based on Particle System
W. Liu†*, L. Y. Zhu†, B. B. Jin†, & M. Helali‡
†School of Automotive Engineering, Yancheng Institute of Technology, Yancheng, 224051, China
‡Address correspondence to this author at Xiwang Road, Yancheng, China. Postcard: 224051;
ABSTRACT: As the traditional Lagrange method considers the connecting rod of the parallel mechanism as a particle, the accuracy of dynamic model tends to be low. In this study, a new dynamic modeling method based on particle system is presented for a six-pyramid parallel mechanism. The kinetic energy and the potential energy of the platform are calculated in terms of energy, and the inertia matrix is obtained. On the premise of fast calculation speed, the connecting rod is considered as a particle system. The kinetic energy and the potential energy of the connecting rod are calculated, and then the dynamic model of the six-pyramid parallel mechanism is established. To verify the correctness of the mathematical model, the prototype and its control system are developed based on dSPACE real-time simulation system. The comparative experiments are done according to a six-dimension trajectory task, and the force variation of the actuators calculated with the traditional Lagrange method and that calculated with the method based on particle system are compared with the actual variation. The results show that the dynamic model using the particle method can reduce errors by up to 60% than that using the traditional method. This research has laid the foundation for further application of parallel mechanisms in the mechanical industry.
Keywords : Parallel mechanism; Dynamics; Particle system; Prototype.
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