Design of a biped robot for supporting an object transportation task

Although there exist devices that support an object transportation task such as a handcart, most devices are based on a wheel-type mobile mechanism, and hence it is difficult to move an object on a floor with high steps. Because a walking-type mobile mechanism enables to move up and down steps, it is expected to support an object transportation task in an environment with stairs or high steps. This paper presents a biped robot that supports an object transportation task up stairs for a human operator based on a prescribed path. First, we present a design of a biped robot with four actuators for a hip and knee joints of each leg. Next, we derive dynamics of the biped robot for simulation in which force applied by a human operator and reaction force from the ground are considered. Experimental results demonstrate that the developed system successfully climb the stairs under the human operation.