Tooltip Motion Control of Hydraulic Robot with Joint Speed Constraints

In this paper, we present a new method of velocity level tooltip trajectory planning when velocity constraints exist for a non-redundant robot. The new method incorporates a binary search algorithm whose goal is to optimize an objective function to minimize the directional and magnitude error between a desired end effector velocity command and the actual velocity when a joint in the robot violates a minimum speed limit. The method was first tested using simulation of an Adept Cobra i800 SCARA robot, then applied to a 6-joint hydraulic robot. The results showed that, depending on the case, up to 50% improvement over other methods could be obtained.