Design of an Energy Efficient Electric Quadruped Robot based on Gravitationally Decoupled Actuation

Mammalian entertainment robots are popular for their friendly appearance, yet few achieve true legged locomotion due to high motor torque and power consumption requirements. In this study, we propose a mammalian electric quadruped walking robot employing Gravitationally Decoupled Actuation (GDA), which enables high-speed locomotion while minimizing the power required for walking. Using a dynamics simulator, we compared two configurations―conventional rotary joint actuation and the GDA model―and evaluated their motor torque and power requirements. Furthermore, based on commercial actuator specifications, we examined the feasibility of a practical GDA-based design. We also investigated a gravity compensation mechanism aimed at reducing motor peak torque and enabling long-duration operation. Simulation results showed that the GDA configuration reduced torque and power demand, achieving approximately 2.24 times the walking speed of the rotary joint actuation model under the same power limit. Introducing gravity compensation further reduced peak torque during the stance phase, making the system more suitable for prolonged operation.