Single CMG-driven quasi-passive dynamic walker

Abstract In robotics, control moment gyroscope (CMG) applications are limited to attitude control, and there are only a few examples of its use for other purposes. Especially, to the best of the author’s knowledge, there are no examples of walkers using CMGs for driving. This paper presents a quasi-passive walker that achieves walking and turning using a single CMG unit. The walker uses a CMG unit to actively create rolling motion. This eliminates the need for passive synchronization and facilitates the design and implementation. Since the rolling is controlled actively, asymmetric roll motion can be easily excited, which leads to active control of the walking direction. The mechanical implementation adopts a unique sole design consisting of two cylindrical surfaces to solve the foot scuffing problem that limits the walking stride. The experimental results showed that a larger stride than the previous studies was obtained by solving the foot scuffing problem. The results also showed that the walker can turn, which can be controlled by adding a bias value to the CMG command. Although the walking direction fluctuated widely among the trials, the results indicated the possibility of controlling the walking direction using a single CMG unit.