Center of gravity estimation and control for a field mobile robot with a heavy manipulator

This paper reports on the study of the Center of Gravity (COG) for the ALACRANE mobile robot, which consists on a hydraulic tracked vehicle with a customized heavy manipulator. The COG has been experimentally estimated by taking into account different arm positions. These estimations have been used to modify the mass distribution of the robot so that the COG can be appropriately controlled online by using onboard inclinometers. This analysis is necessary because the robot has to move on inclined terrains, where tip-over problems are present. During navigation, only three actuators are available: the two track speeds and the arm base rotation. Thus, the arm base rotation is employed to improve static tip-over stability according to the supporting polygon principle. Experimental results from this work are discussed in the paper.