Collision-Free Trajectory Planning for Two Manipulators (The Case of Specified Joint Paths)

In this paper a method for collision-free trajectory planning along specified paths of two manipulators in a common workspace is presented. One of two manipulators is designated to be the master and the other the slave by giving motion priority. The motion of the master is constrained by limitations of input torques/forces and that of the slave by limitations of input toques/forces and collision-free conditions. The dynamic equation of the manipulator is expressed by the path parameter‘s’ which does not depend on time. The quantity λ(s) which connects the time t and the path parameter ‘s’ is introduced. Optimizations of λ(s)'s for minimizations of travelling times are carried out by the dynamic programming for the master and the slave. Finally, the proposed method is applied to two manipulators with two links. Numerical result of the example shows the effectiveness of the method.