A dual control moment gyroscope driven spherical robot for continuous high-torque locomotion

Spherical robots provide inherent mechanical protection and robust mobility for operation in industrial and unstructured environments. However, the performance of existing spherical platforms in complex environments is constrained by limited torque density and reliance on burst-mode torque delivery, impeding obstacle surmounting, slope climbing, and all-weather operation. We present a lightweight and sealed spherical robot actuated by dual control moment gyroscopes (dual-CMG). Leveraging the compact design and high power density of the dual-CMG module, which converts rotor kinetic energy into torque through precession, the system directly couples precessional torque to the robot shell, enabling continuous high-torque rolling locomotion on complex terrain without relying on burst-mode energy accumulation and release. A design-oriented torque analysis is developed to relate dual-CMG torque output to representative high-load locomotion tasks. Experimental results with the prototype demonstrate the effectiveness and practical feasibility of the proposed actuation architecture. The robot is capable of ascending a 23^∘ slope and overcoming vertical obstacles approaching half the sphere radius, demonstrating strong maneuverability in challenging terrain.