The working area and working time are restricted for human under hazardous environment such as high radiation environment or disaster sites. For this reason, we have developed a remotely operated quadruped robot which can walk on uneven terrain such as stairs and slopes. We focused attention on using this robot for carrying various tools and materials for decommissioning work to enlarge workability in hazardous environment instead of personnel. When the arm for handling loads is mounted on the robot, the conveyable load is decreased by weight of the arm. Therefore, we realized unloading task using two of its legs as handling arms. This enables to carry the load which is equal to the maximum payload of the robot. Since the leg tip of this robot is not designed to handle objects, the lifting lug whose shape fits the leg tip was attached to the carrying tray. This unloading task was validated by simulation and experiments. Moreover, we have developed stable walking control method on unsteady or uneven terrain such as rubbles by dynamically keeping balance using posture sensors. This control method can improve robustness of walk with loads, and enhanced practicality of this robot.
