Dynamic modeling of flexible parallel robot

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.