On the Hybrid Kinematics of Tethered Mobile Robots

Tethered mobile robots have for a long time been utilized in search and rescue and operations in inaccessible or hazardous environments. From inspection and cleanup inside nuclear waste tanks to underwater inspection, tethers and umbilical cords have been a reliable means of uninterrupted power supply, high-bandwidth communication, and means of deployment and/or recovery in cases of system failure. While often tethered robots are teleoperated, this may not always be the case, and this paper is concerned with aspects of tether monitoring and management which are central to autonomous operations. Specifically, the paper reports on a method to approximate tether shape and configuration in cluttered workspaces for mobile robots equipped with spooling mechanisms capable of releasing or collecting a cable having its free end fixed at a point in the workspace.