Time-energy optimal path tracking for robots: a numerically efficient optimization approach

Abstract

This paper focuses on time-optimal and time-energy optimal path tracking, which are subproblems in optimal motion planning of robot systems. Through a nonlinear change of variables, the time-energy optimal path tracking problem is transformed here into a convex optimal control problem with a single state variable. A direct transcription method is presented that reduces finding the globally optimal trajectory to solving a second-order cone program using robust numerical algorithms that are freely available. Application to a six-DOF KUKA 361 industrial robot carrying out a writing task illustrates the practicality of the new method.