Biologically Inspired Robotic Leg for High-speed Running

Low speed and low energy efficiency are intrinsic issues to be tackled in the study of legged robots. To cope with these problems, this paper presents a bio-inspired design methodology and its implementation on the compliant robotic leg. The proposed robotic leg achieves excellent performances for the high-speed running with low inertia, high energy reusability and large workspace. Moreover, its joint design has great benefits of large passive deflection angle, and linear stiffness. According to our study, the error between the calculated and the measured stiffness curve of the unidirectional compliant joint mechanism is less than 2% and the joint stiffness can be handled as a constant number. To validate the idea, we demonstrate the robotic leg periodically jumps in the vertical direction, and stores the 18 % of its initial potential energy.