Structural Design for Omni-Directional Mobile Base of Passive-type Mobile Robot

We have developed a passive-type mobile robot based on the concept of the passive robotics. Different from the active-type robot with servo motors, the developed passive-type robot is controlled by using the servo brakes, in which its driving force is applied by a human operator. Therefore, the original motion characteristics of the robot with respect to the human handling force are very important for its maneuverability and it is changed by the structural design of the robot such as the arrangement of the wheels. In this paper, we investigate the original motion characteristics of the passive-type omnidirectional mobile robot and discuss the equilibrium orientation of the robot and the required handling force of the human operator. Finally, we consider the appropriate arrangement of the wheels of the robot for realizing the human support system such as object handling system and the walking support system.