An Efficient Minimum-Time Robot Path Planning under Realistic Conditions

In this paper, we have developed a method for minimum-time path planning in joint space subject to realistic constraints. This method differs from others in that: (i) an absolute path deviation at each corner point of the path can be specified, (ii) local upper bounds on joint accelerations are derived from the arm dynamics so as to nearly fully utilize robot´s capabilities, and (iii) a set of Local optimization problems--one at every local corner point--are employed to replace the global minimum-time problem, thus making the minimum-time path planning problem simpler. As a demonstrative example, we have applied the method to the path planning of the first three joints of the Unimation PUMA 600 series manipulator. The example has indeed shown significant improvements in the total traveling time in addition to the computational simplicity obtained from the decomposition of the global problem into a set of local problems.