Controlling the Motions of an Autonomous Vehicle using a Local Navigator

摘要

This paper addresses the problem of controlling the motion of an autonomous vehicle. This research is carried out within the framework of the French INRIA/INRETS Praxitele project on public transporation by individual electric cars. In this project the cars must have the ability to perform certain motions autonomously. For that purpose we have designed a specific control architecture based upon a local navigator, which projects in the robot evolution space admissible trajectories, called escape lines, on a short time horizon using a direct model of the mobile robot. After the removal of the escape lines that cross some obstacles, it chooses the best escape line that matches with the planned path and delivers it to the inputs of the servo controllers of the vehicle. The trajectories delivered by the local navigator respect the kinematic and dynamic constraints of the vehicle (as embedded in the direct model that is used). since the local navigator only requires a proximity map obtained from sensory data rather than an exhaustive map of the vehicle's environment, its running time is low.