Extension and customization of self-stability control in compliant legged systems
Extension and customization of self-stability control in compliant legged systems
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DOI：
10.1088/1748-3182/7/4/046002
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发表时间：
2012-12-01
影响因子：
3.4
通讯作者：
Blickhan, R.
中科院分区：
文献类型：
--
作者：
Ernst, M.;Geyer, H.;Blickhan, R.
近期关于动物和机器人跑步中有腿运动控制的几项研究聚焦于不同腿部参数对步态稳定性的影响。在先前的一项研究中，通过仔细研究飞行阶段经过精心调整的腿部方向所决定的系统动力学，可以获得呈现无差拍行为的自稳定性控制。这种控制能够适应地面高度的干扰，而无需对其进行检测。在此，我们从两个方面进一步拓展了该方法。除了腿部方向，我们还允许在飞行过程中腿部刚度发生变化，并表明这种扩展极大地提高了对地面干扰的抑制能力。以一个类似人类的例子来说，在多个步幅中对地面高度随机变化的容忍度从腿部长度的3.5%提高到了35%。在单个步幅中，大约70%腿部长度（向上或向下）的变化都可以应对。可变的腿部刚度不仅允许以使步幅容忍度最大化的平坦腿部方向开始，还增加了控制子空间。这使得能够定制自稳定性控制，并考虑动物和机器人中存在的物理和技术限制。
Several recent studies on the control of legged locomotion in animal and robot running focus on the influence of different leg parameters on gait stability. In a preceding investigation self-stability controls showing deadbeat behavior could be obtained by studying the dynamics of the system in dependence of the leg orientation carefully adjusted during the flight phase. Such controls allow to accommodate disturbances of the ground level without having to detect them. Here we further this method in two ways. Besides the leg orientation, we allow changes in leg stiffness during flight and show that this extension substantially improves the rejection of ground disturbances. In a human like example the tolerance of random variation in ground level over many steps increased from 3.5% to 35% of leg length. In single steps changes of about 70% leg length (either up or down) could be negotiated. The variable leg stiffness not only allows to start with flat leg orientations maximizing step tolerances but also increase the control subspace. This allows to customize self-stability controls and to consider physical and technical limitations found in animals and robots.