Rosendo Andre, Iida Fumiya
Department of Engineering, The University of Cambridge, Cambridge, UK.
Bioinspir Biomim. 2016 Apr 12;11(3):036002. doi: 10.1088/1748-3190/11/3/036002.
The intrinsic muscular properties of biological muscles are the main source of stabilization during locomotion, and superior biological performance is obtained with low energy costs. Man-made actuators struggle to reach the same energy efficiency seen in biological muscles. Here, we compare muscle properties within a one-dimensional and a two-segmented hopping leg. Different force-length-velocity relations (constant, linear, and Hill) were adopted for these two proposed models, and the stable maximum hopping heights from both cases were used to estimate the cost of hopping. We then performed a fine-grained analysis during landing and takeoff of the best performing cases, and concluded that the force-velocity Hill-type model is, at maximum hopping height, the most efficient for both linear and segmented models. While hopping at the same height the force-velocity Hill-type relation outperformed the linear relation as well. Finally, knee angles between 60° and 90° presented a lower energy expenditure than other morphologies for both Hill-type and constant relations during maximum hopping height. This work compares different muscular properties in terms of energy efficiency within different geometries, and these results can be applied to decrease energy costs of current actuators and robots during locomotion.
生物肌肉的内在肌肉特性是运动过程中稳定的主要来源，并且能以低能量成本获得卓越的生物学性能。人造致动器难以达到生物肌肉所具有的相同能量效率。在此，我们比较了一维和两段式跳跃腿内的肌肉特性。这两个模型采用了不同的力-长度-速度关系（恒定、线性和希尔关系），并利用两种情况下的稳定最大跳跃高度来估算跳跃成本。然后，我们对表现最佳的情况在着陆和起飞过程中进行了细粒度分析，得出在最大跳跃高度时，力-速度希尔型模型对于线性模型和分段模型都是最有效的。在相同高度跳跃时，力-速度希尔型关系也优于线性关系。最后，在最大跳跃高度时，对于希尔型关系和恒定关系，60°至90°之间的膝关节角度比其他形态具有更低的能量消耗。这项工作在不同几何结构中比较了不同肌肉特性的能量效率，这些结果可用于降低当前致动器和机器人在运动过程中的能量成本。
