Redundant Robots for Work in Space—Literature Review

Space robots operate in unconventional environments, which places specific demands on their mechanical, actuation, and control systems. They need to address a variety of challenges in future space exploitation and exploration, such as in-orbit deployment, active debris removal, or servicing operations. Using robots for such applications presents a unique challenge, as a high level of autonomy is required, and the manipulator’s motion affects the position and orientation of the spacecraft. The article presents basic theoretical statements regarding redundancy in space robotics. Various methods for overcoming difficulties in designing, using, and controlling a space robot are considered. Specialized control algorithms based on the null space of the Jacobian matrix and zero reaction maneuvers (ZRMs) are discussed. The review is limited to space robots with one or more arms and does not include mobile and humanoid robots. Furthermore, the primary motion planning algorithms for these systems are evaluated. Redundant space robots are categorized based on their degrees of freedom, number of arms, operational efficiency, primary objectives, and application areas and the most commonly used algorithms for planning movements. The advantages and disadvantages of both redundant and hyper-redundant space robots are analyzed. The objective of this review is to provide a comprehensive overview of the current state and prospects for the development of redundant robots for operation in space conditions.