Reactionless Control of Free-Floating Space Manipulators

This paper presents a new dynamic formulation as well as control scheme for space manipulators in order to drive the end-effector along a desired trajectory while minimizing the base disturbances caused by the arm movements. Through the new dynamic formulation, the end-effector is viewed as a virtual base, and the end-effector variables are also considered as generalized coordinates. As a result, joint controllers can be designed without having to solve for the inverse kinematics problem and computing the derivative of the generalized Jacobian matrix. Consequently, the joint control torque can be obtained analytically through the Lagrange multipliers method. Further, the joint control torque is also obtained through a quadratic programming problem in order to take into account the joint torque constraints. Several case studies are simulated to demonstrate the new control scheme and compare its performance with that of other controllers.