Evaluation of Efficiently Generating Fast Robot Trajectories Under Geometric and System Constraints

This paper investigates and compares some approaches to trajectory generation for an articulated robot with six degrees of freedom. The trajectory to be planned consists of geometrically predetermined segments and phases where the geometry is free. The overall goal is to minimize the time needed for traversing the whole trajectory from a specified start to a terminal configuration. Constraints for the joint angles, velocities, accelerations, and jerks as well as for the joint torques of the robot are taken into account. The optimal solution of this task is calculated as reference. However, this requires considerable computing time. In view of this fact, different parameterizations are investigated. The resulting trajectories require slightly more time for traversing than the optimal one, but they can be calculated more efficiently. Based on four different exemplary trajectories, the proposed approaches are tested and compared on an industrial robot.