On the Global Optimum Path Planning for Redundant Space Manipulators

AbsCrocr-Robotic manipulators wiU play a significant role in the maintenance and repair of space stations and satellites, and other f u m space missions. Robot path planning and control for the above applications should be optimum, since any inetedency in the planning may considerably risk the success of the space mission. This paper prrsents a global optimum path planning scheme for redundant space robotic manipulators to be used in such missions. In this formulation, a variational approach is used to minimize the objective functional. It is assumed that the gravity is zero in space, and the robotic manipulator is mounted on a completely free-flying base (spacecraft) and the attitude control (reaction wheels or thrust jets) is off. Linear and angular momentum conditions for this system lead to a set of mixed holoaomic and nonholonomic constraints. These equations are adjoined to the objective functional using a Lagrange multiplier tcehniquc Tbc formulation leads to a systcm of Diirerential and AJgebRic Equations ( D A W A numerical scheme for forward Integration of this system is pmnted. A planar redundant space manipulator consisting of thrw arms and a base is considered to demonstrate the feuibllity of the formulation. The approach to optimum path planning of redundant space robots is significant Since moSt robots that bave been developed for space applications so far an redundant The kinematic redundancy of space robots o@en eCRclent control and provides the necessary dexterity for extra-vehicular activity that exceeds human capacity.