Dynamic Modeling of Parallel Robots

Abstract

In this chapter, we present the computation of the dynamic models of redundant and non-redundant parallel robots. In order to obtain the inverse and direct dynamic models, first, all closed loops must be virtually opened to make the platform virtually disassembled from the rest of the structure which becomes a tree structure with all joints actuated. The dynamic model of the tree structure and of the free platform is then computed using a systematic procedure based on the Newton-Euler principle, that makes it possible to reduce the computational complexity of the model. Then, the loops are closed using the loop-closure equations and the principle of virtual powers. As a matter of fact, after an introductory section, this chapter will present an effective way to compute the dynamic models of the tree structure robots. Then, the computation of the dynamic models of redundant and non-redundant parallel robots is investigated. Other types of models are also detailed, such that the energy models and the ground reaction models. The chapter ends with a section on the computation of the base dynamic parameters of parallel robots. The dynamic models of some examples of parallel robots are detailed and compared with experiments.