AAS 99-119

Understanding How Time Optimal Control Optimizes the Interaction Forces among Robot Links

G. Giese*, R. Longman**, H. Bock**

Technical University of Zurick, Zurick, Switzerland, **Columbia University, New York, ***Univeristy of Heidelberg, Heidelberg, Germany


This paper seeks to develop a more complete intuitive understanding of the nature of time optimal point-to-point trajectories for robots. Use of time optimal path planning can speed up robots on assembly limes, and allow them to run faster increasing their productivity. In time optimal robot point-to-point motion there is generically one robot axis than has the hardest time reaching its endpoint. And then, to whatever extent other axes have extra freedom, it must be used to help the axis with the hardest task, whenever it can help. Such assistance makes use of Coriolis force, the force related to acceleration in rotating reference toques, and altering the inertia seen by another axis. In this paper we examine two basic types of robots, polar and elbow robots, and examine each of these types of forces during optimal motions, in order to develop understanding of optimal maneuvers.