Variable-resolution velocity roadmap generation considering safety constraints for mobile robots

This research develops a new roadmap method for autonomous mobile robots based on variable-resolution partitioning of a continuous state space. Unlike conventional roadmaps, which include position information only, the proposed roadmap also includes velocity information. Each node of the proposed roadmap consists of a fixed position and a range of velocity values, where the velocity ranges are determined by variable-resolution partitioning of the velocity space. An ordered pair of nodes is connected by a directed link if any combination of their velocity values is within the acceptable range of the nodes and produces a trajectory satisfying a set of safety constraints. In this manner, a possible trajectory connecting an arbitrary starting node and destination node is obtained by applying a graph search technique on the proposed roadmap. The proposed method is evaluated through simulations.