Nonconvex Time-Optimal Trajectory Planning for Robot Manipulators

Time-optimal motion-planning has been a topic of active research in the literature for a while. This paper presents a new approach for velocity profile generation, which is a sub-problem in motion-planning. In the case of simplified constraints, profile generation can be translated to a convex optimization problem. However, some practical constraints (e.g., velocity-dependent torque, viscous friction) destroy the convexity. The proposed method can obtain the global optimum of the nonconvex optimization problem. The experimental results with a three degrees-of-freedom (DOF) robot manipulator are also presented in this paper.