Adaptive Flow Planning of Modular Spherical Robot Considering Static Gravity Stability

Modular robots have a unique obstacle-crossing method, flow. Flow is realized by constantly changing the connection relationship between modules, namely reconfiguration. Existing flow planning methods do not consider the static stability in their adaptation to obstacles. This letter proposes a flow planning method with scalability, adaptability, and static gravity stability. The criterion of static gravity stability is always satisfied through the following two innovations. First, each target configuration in the flow process is designed to grasp obstacles like vines. Second, in motion planning, each module maintains contact with the obstacle or a fixed module to maximize the supporting polygon of the configuration. What’s more, the simplified path output by the connection planning and the precise calculation based on the mesh model realize the scalability and adaptability of the flow planning method. In simulation, we evaluate the adaptability to various obstacles and the margin of static gravity stability.