Development of ASURA I: Harvestman-like hexapod walking robot — Approach for long-legged robot and leg mechanism design

In this paper, a harvestman-like hexapod walking robot named ASURA I is proposed and its leg mechanism design is discussed. Modeled on a harvestman in nature, the authors have introduced the concept of mobile form that has long legs and small body to ASURA I to enhance mobile performance on rough terrain. To develop long legs relative to body, special parallel link mechanism to drive leg joints powerfully and effectively is introduced to leg mechanism of ASURA I. First, we discuss design problems of leg mechanism in detail: leg length, DOF configuration, actuator selection and leg driving system. Then, analysis of kinematics, singularity and static characteristic of leg mechanism are reported. Finally, the prototype leg, which is 1.3 m in length and 3.2 kg in weight, has been developed and tested on some basic performance. The prototype successfully have demonstrated very basic motion.