Time-Optimal Playback Trajectory Generation for Hydraulic Material Handling Excavator

Assistance functions are applied in many areas. For material handling excavators, these functions have not been introduced yet. In this paper, an optimization based trajectory generation which minimizes the travel time of a taught trajectory is presented. This playback optimization considers actuator constraints such as velocity, acceleration, jerk and maximum flow rate of the hydraulic pump. A position and velocity controller is designed based on a simplified dynamic model of the actuator in a two-degree-of-freedom control structure. Experimental results on a material handling excavator are presented. The results show the ability of the playback optimization to generate a time-optimal trajectory, considering the given constraints, and the controller to track the reference values.