Comparative experimental and theoretical approaches on multi-legged locomotion – Using fast running insect, arachnid, isopod and centipede species for examining leg coordination and body dynamics with increasing numbers of propulsive legs and running spee

机器人的应用在我们的日常生活中变得越来越普遍，并将很快包括先进的自主辅助技术。由于人类环境中充满了各种各样的障碍，而腿式系统在不平坦的地形上表现出色，因此除了车轮之外，许多这些设备还将依赖于某种腿式推进装置。多足运动装置本质上提供了高度的静态稳定性。因此，是时候更好地理解多足运动了。节肢动物是这种多足动物结构的自然模型和主要例子。然而，在快速移动的多足动物中，不同腿数对身体动力学的影响仍未得到充分的研究。因此，本应用程序旨在对不同节肢动物物种的陆地运动进行实验和理论研究，涵盖了从少到多的过渡区域的一系列腿数。对这些生物的运动生物力学、峰值表现和控制的了解也将促进我们对迁徙过程和生态系统动力学的理解。到目前为止，现有的数据只涵盖了少数物种。然而，这些例子物种根本不能代表节肢动物中运动器官的全部财富。同样，许多关于节肢动物运动的数学模型忽略了推进腿的实际数量，而只关注水平运动动力学。最近，我展示了昆虫和蛛形纲动物在从中速到高速奔跑时腿部协调性的变化。这些变化影响身体动力学、能量学和跑步稳定性。此外，在建模研究中，我能够揭示轻微的协调变化对身体动力学和能量学的影响随着推进腿数量的增加而增加。由于这种微小的协调变化到目前为止一直被忽视，自然发生的步态变化很可能在大量节肢动物物种中被忽视。因此，本提案旨在通过检查一系列昆虫、蛛形纲动物、等足类动物和蜈蚣物种的稳定运动，包括峰值表现，从生物学模型中获得知识。实验物种都是类似的大小，有外骨骼的变温动物，这减少了这些特征对结果的影响。在高速奔跑时，它们分别使用2对、3对、4对、7对和14对腿。它们的运动将通过高速运动学、半自动跟踪技术和先前开发的分析技术进行检查。通过将预期实验的结果与已建立模型的预测结果进行比较，将有可能检验这些模型的关键预测。此外，最近开发的模型概念将通过实施额外的参数（如噪音和不规则的地面反作用力）来增强，这将能够评估这些参数对多足运动的影响。

Robotic applications are becoming increasingly prevalent in our everyday life, and will soon include advanced self-propelled assistive technology. Since human environments are full of a wide range of obstacles, and legged systems excel on uneven terrain, many of these devices will, in addition to wheels, also rely on some sort of legged propulsive apparatus. Multilegged locomotor apparatuses intrinsically provide a high degree of static stability. Accordingly, it is high time for a better understanding of multilegged locomotion. Arthropods are natural models and prime examples for such polypedal structures. However, the impact of different leg numbers on body dynamics in fast moving polypedal animals is still underexplored. Consequently, this application aims at experimental and theoretical examinations of terrestrial locomotion in different arthropod species covering a range of leg numbers in the transition zone from few to many. Knowledge gained on these organisms’ locomotion biomechanics, peak performance and control will also advance our understanding on migratory processes and ecosystem dynamics. So far, available data covers only a handful of species. These example species, however, do not at all represent the entire wealth of locomotor apparatuses available in arthropods. Likewise, many mathematical models on arthropod locomotion disregard the real number of propulsive legs and focus exclusively on horizontal running dynamics. Recently, I have shown that insects and arachnids shift leg coordination when changing from intermediate to high running speeds. These changes impact body dynamics, energetics and running stability. Moreover, in a modelling study I was able to reveal the increasing impact of slight coordinative changes on body dynamics and energetics as the number of propulsive legs increases. Since such small coordinative changes have been neglected so far, naturally occurring gait changes are likely to have been overlooked in a large number of arthropod species. Consequently, the present proposal aims at gaining knowledge from biological models by examining steady locomotion, including peak performance, in a range of insect, arachnid, isopod and centipede species. The experimental species are all similarly sized, poikilotherms with exoskeletons, which reduces the impact of these features on the results. When running at speed, the species use 2, 3, 4, 7 and 14 pairs of legs. Their movements will be examined via high speed kinematics, semi-automated tracking techniques and previously developed analytical technology. By comparing the results of the intended experiments to the predicted outcomes of established models, it will be possible to test crucial predictions of those models. Furthermore, recently developed model concepts will be enhanced by implementing additional parameters such as noise and irregular ground reaction forces, which will enable the assessment of these parameters’ impact on multilegged locomotion.