BLIND RRT: A PROBABILISTICALLY COMPLETE, DISTRIBUTED RRT

Abstract

Rapidly-Exploring Random Trees (RRTs) have been successful at finding feasible solutions for high-dimensional problems. With motion planning becoming more computationally de- manding, we turn to parallel motion planning for efficient solutions. Existing work on dis- tributed RRTs has been limited by the overhead that global communication requires. A recent approach, Radial RRT, demonstrated a scalable algorithm that subdivides the space into regions to increase the locality of the computations. However, if an obstacle completely blocks RRT growth in a region, the planning space is not covered and thus planning problems cannot always be solved. We present a new algorithm, Blind RRT, which ignores obstacles during initial growth to efficiently explore the entire space. Because obstacles are ignored, free components of the tree become disconnected and fragmented. Thus, Blind RRT merges parts of the tree that have become disconnected from the root. We show how this algorithm can be applied to the Radial RRT framework allowing both scalability and usefulness in mo- tion planning. We show this method to be a probabilistically complete approach to parallel RRTs. We show that our method not only scales, but also overcomes the motion planning limitations that Radial RRT has in a series of difficult motion planning tasks. The results show Blind RRT as a scalable strategy capable of effectively covering the space.