EFFICIENT DYNAMIC SIMULATION OF MULTIPLE CHAIN ROBOTIC MECHANISMS

An efficient O(mN) algorithm for the dynamic simulation of simple clos ed-chain robotic mechanisms is presented in this paper, where m is the number of chains, and N is the number of links for each chain. A wide range of contact conditions between each of the chains and the suppor t surface or common body, load, or object may be simulated so that the algorithm is applicable to multilegged vehicles, multiple manipulator s, and dexterous hands. The algorithm is based on the computation of t he operational space inertia matrix (6 x 6) for each chain as seen by the common body, load, or object. Computation of the open-chain dynami cs for each chain is also required, and the most efficient algorithm k nown is used for this purpose. The total computation required is tabul ated in terms of the number of scalar operations needed. Efficient spa tial transformations form the basis for these computations. Parallel i mplementation of the dynamics calculations for each chain and the comm on body results in an O(N) + O(log2 m) algorithm.