Design and Fabrication of a Bipedal Robot Using Serial-Parallel Hybrid Leg Mechanism

Abstract

In this paper, we present the design and performance evaluation of a bipedal robot that utilizes the Hybrid Leg mechanism. It is a leg mechanism that achieves 6 DOF with a combined structure of serial and parallel mechanism. It is designed to have a light structural inertia and large workspace for agile bipedal locomotion. A new version of Hybrid Leg is fabricated with carbon fiber tubes and bearings to improve its structural rigidity and accuracy while supporting its weight. A pair of Hybrid Legs is assembled together for bipedal locomotion. In the assembly, we adopt a pelvis structure with an yaw angle offset to enlarge the feet workspace, inspired by the toe-out angle of the human feet. The workspace and range of velocity are presented in simulation and verified with hardware experiments. We also demonstrate a simple forward walking motion with the developed robot.