Mapping a Space Manipulator to a Dynamically Equivalent Manipulator

In this paper, we discuss the problem of how a free-floating space manipulator can be mapped to a conventional, fixed-base manipulator which preserves both its dynamic and kinematic properties. This manipulator is called dynamically equivalent manipulator (DEM). The DEM concept not only allows us to model a free-floating space manipulator system with simple, well-understood methods, but also can be physically built using a conventional manipulator system to experimentally study the dynamic performance and task execution of a space manipulator system, without having to resort to complicated experimental set-ups to simulate the space environment. This paper presents the theoretical dcuelopment of the DEM concept, demonstrates the dynamic and kinematic equivalence, discusses the effect of model uncertainty with respect to the mapping, and prescnts simulation results to illustrate the equivalence in both open-loop and close-loop controls.