Biomimetic Design and Optimal Swing of a Hexapod Robot Leg

• Published in: Journal of bionics engineering 2014-01, Vol.11 (1), p.26-35
• Main Authors: Chen, Jie, Liu, Yubin, Zhao, Jie, Zhang, He, Jin, Hongzhe
• Format: Article
• Language: English
• Subjects: Artificial Intelligence; Biochemical Engineering; Bioinformatics; biological movement principle; Biomaterials; Biomedical Engineering and Bioengineering; Biomedical Engineering/Biotechnology; biomimetic design; Engineering; Gauss pseudospectral method; legged robot; optimal control; 仿生设计; 优化; 六足机器人; 控制方案; 摆动; 生物系统; 肌肉系统; 解剖结构
• ISSN: 1672-6529; 2543-2141
• DOI: 10.1016/S1672-6529(14)60017-2

Biological inspiration has spawned a wealth of solutions to both mechanical design and control schemes in the efforts to develop agile legged machines. This paper presents a compliant leg mechanism for a small six-legged robot, HITCR-II, based on abstracted anatomy from insect legs. Kinematic structure, relative proportion of leg segment lengths and actuation system were analyzed in consideration of anatomical structure as well as muscle system of insect legs and desired mobility. A spring based passive compliance mechanism inspired by musculoskeletal structures of biological systems was integrated into distal segment of the leg to soften foot impact on touchdown. In addition, an efficient locomotion planner capable of generating natural movements for the legs during swing phase was proposed. The problem of leg swing was formulated as an optimal control procedure that satisfies a series of locomotion task terms while minimizing a biologically-based objective function, which was solved by a Gauss Pseudospectral Method (GPM) based numerical technique. We applied this swing generation algorithm to both a simulation platform and a robot prototype. Results show that the proposed leg structure and swing planner are able to successfully perform effective swing movements on rugged terrains.