Collision-free Traiectory Planning For Robot Manipulators†

Abstract

In this paper we present an algorithm for generating trajec- tories for a robot manipulator operating in an environment containing obstacles. The algorithm uses B-splines to generate trajectories in joint space with the constraint that the corresponding Cartesian space trajectories lie within specified tolerances. The latter is accomplished by modifying the joint space trajectory using an optimal search technique such that the constraints on the Cartesian space trajectory are satisfied. An important feature of the proposed algorithm is that an accurate joint space specification of the trajectory is available without performing numerous cornputationally expensive inverse kinematic transformations to convert a Cartesian space trajectory to a joint space trajectory. Further-more, by appropriately specifying the tolerance limits on the Cartesian space trajectory, we can ensure that collisions with obs tacles in Cartesian space are avoided. The use of the algorithm is PUMA 560 robot.