Fast Generation of Multiple Collision-Free and Linear Trajectories in Dynamic Environments

A fast and complete collision-detection procedure is presented in this paper. Given a straight-line path for a mobile robot, the current instant of time, and estimations of the obstacles motions, a set of speeds is obtained in real time with neither space nor time discretization. The mobile-robot path together with each one of these speeds, if they exist, states a different collision-free trajectory. All these trajectories verify that the minimum distance between the mobile robot and the obstacles at anytime is greater than or equal to a configurable parameter. This set of speeds is fast updated when a change in the original mobile-robot path is considered. If the current mobile-robot speed does not belong to the mentioned set of speeds, then the mobile robot will collide with at least one obstacle and, in this case, a set of accelerations is fast-tuned to avoid all the obstacles. Collision-free trajectories that do not verify the dynamic constraints of the mobile robot are simply rejected.