Kinodynamic Motion Planning for Mobile Robots Using Splines

This paper presents an approach to time-optimal kinodynamic motion planning for a mobile robot. A global path planner is used to generate collision-free straight-line paths from the robot's position to a given goal location. With waypoints of this path, an initial trajectory is generated which defines the planned position of the robot over time. A velocity profile is computed that accounts for constraints on the velocity and acceleration of the robot. The trajectory is refined to minimize the time needed for traversal by an any-time optimization algorithm. An error-feedback controller generates motor commands to execute the planned trajectory. Quintic Bezier splines are used to allow for curvature-continuous joins of trajectory segments, which enables the system to replan trajectories in order to react to unmapped obstacles. Experiments on real robots are presented that show our system's capabilities of smooth, precise, and predictive motion.