Trajectory Tracking Control of an Excavator Arm Using Guaranteed Cost Control

Improving excavators control systems allows increasing efficiency and productivity of these machines, reduces loads on an operator and improves his safety. One of the stumbling blocks in the way of improving an excavator control system is uncertainty of high dynamic loads during the bucket and soil interaction. Therefore, this paper deals with the problem of robust trajectory tracking control of an excavator bucket during digging. The optimal inverse kinematic solution is used to determine the joint angles, given in the base coordinate system. To control an excavator arm movement, the computed torque control with the guaranteed cost control is designed. The mathematical tool of R-functions for state estimation of an excavator arm is used. Simulation results and functional ability analysis for the proposed control system are given. Some intermediate outcomes concerning the sensing part of the robotic excavator prototype, that is being developed, are presented.