Trajectory Planning for Tethered Robots in Uncertain Environments

Abstract

The present paper considers the problem of planar motion planning for environments with partially unknown obstacles for a robot with tether connection and missions with multiple target positions. The presence of a tether increases the complexity of the already challenging problem of dynamic motion planning by introducing additional feasibility constraints, i.e. not entangling the cable in any of the obstacles within the working space. For a given mission, the developed algorithm finds a closed trajectory such that after its execution the cable can be retrieved without difficulties. It combines the dynamic path-planning capabilities of the RRT ^X (Rapid-exploring Random Tree X) method with a geometric approach that efficiently identifies feasible paths that satisfy all the criteria imposed by the problem. Extensive simulation tests demonstrate the validity and reduced computational complexity of the proposed solution.