Impact analysis and post-impact motion control issues of a free-floating space robot subject to a force impulse

This article presents impact dynamic analysis of a free-floating space robo t, subject to a force impulse at the hand. We study the joint and the base reactions in terms of finite velocity changes and clarify their role for th e post-impact motion behavior of the robot. The analysis makes use of a joi nt-space orthogonal decomposition procedure involving the so called reactio n null space. The article focuses on the specific case of a nonredundant ar m and a reaction null space in terms of base angular motion. We further sho w that with proper post-impact control it is possible to transfer the whole angular momentum from the base toward the manipulator, and in the same tim e to reduce the joint velocity.