Dynamical analysis of human standing model with cyclic motion
Dynamical analysis of human standing model with cyclic motion
复制标题
循环运动人体站立模型的动力学分析
DOI：
10.1109/biorob.2014.6913848
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Kazuo Tsuchiya
中科院分区：
文献类型：
--
作者：
Tetsuro Funato;Shinya Aoi;Nozomi Tomita;Kazuo Tsuchiya
人体站立的特点是身体摇摆大，这不能用线性控制来解释。在过去的研究中，摇摆被认为是一种不可控的生物噪声。相比之下，我们认为摇摆是一个周期性的运动所产生的连续比例积分微分（PID）控制与弱非线性。通过对非线性PID控制的数学分析，证明了周期性运动是由稳定增益相关的Hopf分岔产生的，而生物噪声有助于平稳稳定状态和周期性状态之间的平稳过渡.通过在不同稳定性的地板上进行人体实验，验证了所提出的摇摆产生机制的相关性。因此，存在的Hopf分支，即，在控制参数略有减小的情况下，观察到由底板失稳实现的侧移明显扩大。
Human standing is characterized by large body sway, which cannot be explained by linear control. In past researches, sway has been considered as an uncontrolled biological noise. In contrast, we consider the sway to be a cyclic motion generated by continuous proportional-integral-derivative (PID) control with weak nonlinearlity. Through mathematical analysis of nonliner PID control, cyclic motion is shown to be generated by a stability-gain dependent Hopf bifurcation, and biological noise is shown to help the smooth transition between stationary stable state and cyclic state. The relevance of the proposed sway generation mechanism is verified through human experiment on floors with different stability. As a result, the existence of Hopf bifurcation, i.e., apparent expansion of sway with small decrease of control parameters, realized by the destabilization of floor, is observed.