Smooth-RRT*: Asymptotically Optimal Motion Planning for Mobile Robots under Kinodynamic Constraints

Nowadays, various algorithms based on the Rapidly-exploring Random Tree (RRT) methods are utilized to solve motion planning problems. Based on the RRT*, we developed a novel reconnection method that enables the planner to directly generate a smooth curved trajectory. Meanwhile, kinodynamic constraints of the robots are considered to generate the control input, which improves the feasibility of the algorithm. The trajectory planned by the Smooth-RRT* is significantly suitable for the non-holonomic robots. Planning tests are conducted in four scenarios to demonstrate performance of the proposed algorithm in comparison with the original RRT* and kinodynamic-RRT (Kino-RRT). Smooth-RRT* yields shorter and smoother planned path in all the scenarios compared with the Kino-RRT. It finds a solution with fewer expansion nodes than the RRT* under the same time consumption. The results demonstrate that the proposed algorithm can generate a smooth trajectory satisfied with the kinodynamic constraints and ensure the asymptotic optimality.