Modeling and Optimization of an Arc-Shaped Sliding Locomotion Robot with Wobbling Mass

Recently, several indirectly controlled sliding robots have been designed to achieve efficient and stable locomotion on slippery surfaces, and numerical simulations proved their possibility. However, it is difficult to achieve the same performance on a real machine because the wobbling mass, composed of springs and dampers, shows unexpected behavior when it is moved in translation. In this study, we propose a model of an arc-shaped sliding locomotion robot with a rotating wobbling mass. Specifically, the position of the center of gravity of the robot was changed, and the pull-in phenomenon due to the rotational motion of the wobbling mass is utilized. By rotating the wobbling mass, the sliding motion is realized while maintaining a strong propulsive force. First, we performed experimental validation of the proposed new mechanism. Subsequently, a detailed mathematical model was constructed for numerical analysis. Finally, the motion performance was optimized by the Bayesian optimization method.