Stable pulling out motion for a dual-arm robot

Many disaster response robots have been studied and developed to reduce the risk of secondary disaster. These robots are expected to improve efficiency and safety. In this paper, we consider a task that a dual-arm disaster response robot pulls a bar whose length and mass are unknown out of a wall as debris removal. Safe working is important in the disaster site to remove debris. Therefore, our objective is to develop a stable pulling out motion. To achieve pulling a target bar out stably, we need to know the physical parameter of the bar. Therefore, the robot uses force/torque sensors attached to the wrists of the robot to estimate the mass and center of gravity position of the bar. Then, the robot controls the bar attitude with the estimated parameters after the bar is pulled out of the wall. Experimental results for verification show the effectiveness of the proposed motion.