Dynamic Modeling of Flexible Parallel Robot

Abstract:

An accurate and simple method for dynamic modeling of general flexible parallel robot was proposed. According to the structural character of the parallel robot, it was devided into rigid sub-structure and elastic sub-structure, and the rigid-flexible coupling system was formed. The static platform and mobile platform were treated as rigid sub-structure because its deformations were smaller compared to the other part. The chains were treated as flexible sub-structure. The dynamic equations of each sub-structure were obtained, respectively. The dynamic equations of elastic sub-structure were obtained by using the finite element method and mode synthesis method. The dynamic equations of rigid sub-structure were built accounting for the effects of deformation of flexible sub-structure. The geometrical constraint relationship between three flexible sub-structures and the rigid platform was investigated to obtain a simple displacement and dynamic relation between them. The equations of all sub-structure were assembled to get the system dynamic equations. The comparative analysis of dynamic characteristics of a high-speed parallel manipulator show that the method is correct and feasible. Due to introducing the rigid sub-structure and application of the mode synthesis, the number of system freedom was reduced and the computational modeling was simplified. It provided a practical method for flexible parallel robot.