RRT*-smooth Algorithm Applied to Motion Planning of Concentric Tube Robots

Concentric tube robots have broad prospects for the development of minimally invasive surgery. Concentric tubes consist of super-elastic nickel-titanium alloys, so they can exhibit different shapes when they are relatively rotated or translated. Moreover, compared to traditional robots, concentric tube robots are smaller and more flexible, they can work in tight spaces or complicated environments consequently. In this paper, for the application of concentric tube robot with dominant stiffness, the forward kinematics calculation formula and the detailed inverse kinematics geometry method are given. In addition, RRT*-smooth algorithm is proposed after smoothing twice based on RRT*, and compared with other motion planning algorithms. Experiments show that it can quickly plan a shortest path while guaranteeing collision-free.