Motion planning for dual-arm manipulation of elastic rods

We present a novel motion planning strategy for the manipulation of elastic rods with two robotic arms. In previous work, it has been shown that the free configuration space of an elastic rod, i.e., the set of equilibrium shapes of the rod, is a smooth manifold of a finite dimension that can be parameterized by one chart. Thus, a sampling-based planning algorithm is straightforward to implement in the product space of the joint angles and the equilibrium configuration space of the elastic rod. Preliminary results show that planning directly in this product space is feasible. However, solving for the elastic rod's shape requires the numerical solution of differential equations, resulting in an excessive and impractical runtime. Hence, we propose to pre-compute a descriptor of the rod, i.e., a roadmap in the free configuration space of the rod that captures its main-connectivity. By doing so, we can plan the motion of any dual-arm robotic system over this roadmap with dramatically fewer solutions of the differential equations. Experiments using the Open Motion Planning Library (OMPL) show significant runtime reduction by an order of magnitude.