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[2021-Vol.19-Issue 4]Bio-inspired Leg Design for a Heavy-Duty Hexapod Robot
Post: 2022-09-15 08:53  View:63

Journal of Bionic Engineering (2022) 19:975–990 https://doi.org/10.1007/s42235-022-00192-2

Bio-inspired Leg Design for a Heavy-Duty Hexapod Robot

Haoyuan Yi1  · Zhenyu Xu1,2 · Xueting Xin2  · Liming Zhou2  · Xin Luo1

1 State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China

2 Research Institute, Inner Mongolia First Machinery Group Co. Ltd, Baotou 014030, China

Abstract The leg structure is crucial to the legged robot's motion performance. With the size and load of the legged robot increasing, the difculty of leg design increases sharply. Inspired by biomechanics, this paper proposes a leg design approach based on efective mechanical advantage (EMA) for developing the heavy-duty legged robot. The bio-inspired design approach can reduce the demand for joint actuation forces during walking by optimizing the ratio relationship between the joint driving force and ground contact force. A dimensionless EMA model of the leg for the heavy-duty legged robot is constructed in this paper. Leg dimensions and hinge point locations are optimized according to the EMA and energy-optimal criterion. Based on the optimal leg structure, an electrically driven tri-segmented leg prototype is developed. The leg's joint hinge points are located near the main support line, and the load-to-weight ratio is 15:1. The leg can realize a swing frequency of 0.63 Hz at the stride length of 0.8 m, and the maximum stride length can reach 1.5 m.

Keywords Legged robot · EMA · Heavy-duty · Bio-inspired

Moment balance of the muscle force (f$f$) relative to the ground reaction force (Fr${F}_{\text{r}}$), which depends on the moment arms (r$r$ and R$R$)

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