抄録
Recently, many wheeled robots with an ability to pass over rough roads and steps have been developed. However, the structures of such robots are generally very complicated with many degrees of freedom. Therefore, we have developed a four-wheeled robot which has the ability of passing over a step with simple structure. We call it a variable structure type four-wheeled robot. For the realization of stepping over, there are several difficult problems to be solved, such as control methods for state transfer and stabilization in 2-wheeled state. In this paper, we mainly discuss control methods for transfers from 4-to 2-wheeled state and from 2-to 4-wheeled state. Especially in the transfer from 4-to 2-wheeled state, we make effective use of the driving torque of body's motor. In the transfer from 2-to 4-wheeled state, we have investigated a control method for soft landing to minimize the touch-down impact of the robot. By combining our control methods, we have realized an experiment of passing over a step successfully.