A Biomimetic and Energy-Efficient Leg Design for a Humanoid Robot: An Exclusively Linear-Actuated Implementation

The mobility and manipulation of bipedal humanoid robots always depend on their legs, which account for balance and may substantially accelerate energy consumption, especially when the lower body is expected to be stationary. To this end, this article presents a biomimetic and energy-efficient design for bipedal robots’ legs and extensively demonstrates its performance on the developed prototype. From a biomimetic perspective, human walking data are captured at first, and the range of motion, speed, and coupling relationship of various joints are analyzed. The skeletal and muscular structures of each joint are then dissected and imitated by mechanism synthesis, where a novel locking mechanism inspired by the biological structure of the knee joint is integrated. To better evaluate the energy consumption capability of legged robots, we propose a new metric—dynamic power of the system (DPoS)—and experimentally prove its rationality. The effectiveness and superiority of our design are ultimately validated through the comparative experiments on both our prototype and the off-the-shelf counterpart.