Contact Force Minimization for Space Robot Manipulators using Optimized Sliding Mode Controller

Space exploration involves activities such as inspection, refueling, upgrading, repairing worn space objects, rescuing damaged satellites, removing orbital debris, building and maintaining orbital assets, infrastructures, or maintenance assistance, conducting scientific experiments in space, and missions for planetary explorations. To accomplish such complex tasks in the space environment, space robots are preferred for these activities. The end effector of a space robot is usually associated with a contact force when manipulating or capturing objects in space. Researchers have reported that the excess contact force between the space robot and the captured target object causes damage to both the robot and the target object. The successful manipulation of such objects by robotic systems is crucial for ensuring the safety of the robot and the object in space. This article introduces a novel approach to minimize contact forces during space robot captures by employing a hybrid method that combines configuration optimization techniques with desired trajectory planning and the advanced control method of sliding mode control (SMC). This study aims to enhance the efficiency and safety of object manipulation in a challenging space environment. A holistic and modern particle swarm optimization (PSO) algorithm is employed for the contact force minimization. Extensive numerical simulations in MATLAB were performed for the proposed method. © 2013 IEEE.