Autonomous Sequential Submanoeuvres in Pre- and Post-Capturing Space Objects Using Obstructed 3-D Vision Data

This article presents a vision guidance and control method for autonomous robotic capture and stabilization of a tumbling and drifting target object in a time-critical manner. The method takes into account various operational and physical constraints, including ensuring a smooth capture, handling line-of-sight (LOS) obstructions of the target, and staying within the acceleration, force, and torque limits of the robot. Our approach involves the development of an optimal control framework for an eye-to-hand visual servoing method, which integrates two sequential submanoeuvres: 1) a precapturing manoeuvre and 2) a postcapturing manoeuvre, aimed at achieving the shortest possible capture time. Integrating both control strategies enables a seamless transition between them, allowing for real-time switching to the appropriate control system. Moreover, both controllers are adaptively tuned through vision feedback to account for the unknown dynamics of the target. The integrated estimation and control architecture also facilitates fault detection and recovery of the visual feedback in situations where the feedback is temporarily obstructed. The experimental results demonstrate the successful execution of pre- and post-capturing operations on a tumbling and drifting target, despite multiple operational constraints and the presence of obstructed 3-D vision data.