INSTANTANEOUS KINEMATICS OF GENERAL HYBRID PARALLEL MANIPULATORS

In this paper, we introduce a new class of parallel manipulators, call ed general hybrid parallel manipulators (GHPM). These are modular mani pulators that may contain serial subchains as well as subchains of par allel modules, acting in parallel and connecting a base to a common pl atform. The instantaneous motion of the GHPM is studied by resorting t o the theory of screws. In this context, we define the screw-system an nihilator to reduce, systematically, the number of unknowns involved t o a minimum. The formulation presented here is general and can be appl ied to most existing parallel manipulators, multifingered hands, multi ple coordinated robots and walking machines. To illustrate the basic s ymbolical and numerical aspects of the proposed procedure, the analyse s of the instantaneous kinematics of two hybrid manipulators are inclu ded.