Path-Velocity Decomposition Revisited and Applied to Dynamic Trajectory Planning

| This paper addresses dynamic trajectory planning, which is deened as motion planning for a robot A moving in a dynamic workspace W, i.e. a workspace cluttered up with stationary and moving obstacles. Besides A is subject both to kinematic constraints, i.e. constraints involving the connguration parameters of A and their derivatives, and dynamic constraints, i.e. constraints on the forces, the accelerations and the velocities applied to A. We considerthe case of a car-likerobot A with boundedvelocity and acceleration,moving in a dynamic workspace W = I R 2. Our approach is an extension to thèpath-velocity decomposition' 9]. We introduce the concept of adjacent paths and we use it within a novel motion planning schema which operates in two complementary stages: (a) paths-planning and (b) trajectory-planning. In the paths-planning stage, a set of adjacent paths, one of which leading A to its goal, are computed. These paths are collision-free with the stationary obstacles and respect A's kinematic constraints. In the trajectory-planning stage, knowing that A is able to shift from one path to an adjacent one freely, we determine the motion of A along and between these paths so as to avoid any collision with the moving obstacles while respecting A's dynamic constraints. Abstract | This paper addresses dynamic trajectory planning, which is deened as motion planning for a robot A moving in a dynamic workspace W, i.e. a workspace cluttered up with stationary and moving obstacles. Besides A is subject both to kinematic constraints, i.e. constraints involving the connguration parameters of A and their derivatives, and dynamic constraints, i.e. constraints on the forces, the accelerations and the velocities applied to A. We consider the case of a car-like robot A with bounded velocity and acceleration, moving in a dynamic workspace W = I R 2. Our approach is an extension to thèpath-velocity decom-position' 9]. We introduce the concept of adjacent paths and we use it within a novel motion planning schema which operates in two complementary stages: (a) paths-planning and (b) trajectory-planning. In the paths-planning stage, a set of adjacent paths, one of which leading A to its goal, are computed. These paths are collision-free with the stationary obstacles and respect A's kinematic constraints. In the trajectory-planning stage, knowing that A is able to shift from one path to an adjacent one freely, we determine the motion of A along and between these paths so as to avoid any collision …