Planning Paths for Elastic Objects under Manipulation Constraints

Abstract

This paper addresses the problem of planning paths for an elastic object from an initial to a final configuration in a static environment. It is assumed that the object is manipulated by two actuators and that it does not touch the obstacles in its environment at any time. The object may need to deform to achieve a collision-free path from the initial to the final configuration. Any required deformations are automatically computed by the planner according to the principles of elasticity theory from mechanics. The problem considered in this paper differs significantly from that of planning for a rigid or an articulated object. In the first part of the paper, the authors point out these differences and highlight the reasons that make planning for elastic objects an extremely difficult task. The authors then present a randomized algorithm for computing collision-free paths for elastic objects under the above-mentioned restrictions of manipulation. The paper includes a number of experimental results. The work is motivated by the need to consider the physical properties of objects while planning and has applications in industrial problems, in maintainability studies, in virtual reality environments, and in medical surgical settings.