Planning of Minimum- Time Trajectories for Robot Arms

Abstract

The minimum-time path for a robot arm has been a long standing and unsolved problem of considerable interest. We present a general solution to this problem which involves joint-space tessellation, a dynamic time-scaling algorithm, and a graph search. The solution incorporates full dynamics of movement and actuator constraints, and can easily be extended for joint limits and workspace obstacles. It was found that optimal paths tend to be nearly straight lines in joint space. We discuss implementation difficulties due to the tessellation and to combinatorial proliferation of paths.