Balancing with positive feedback: the case for discontinuous control
Balancing with positive feedback: the case for discontinuous control
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DOI：
10.1098/rsta.2008.0257
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发表时间：
2009-03-28
期刊：
影响因子：
5
通讯作者：
Ohira, Toru
中科院分区：
文献类型：
--
作者：
Milton, John;Townsend, Jennifer L.;Ohira, Toru
实验观察表明，正反馈对保持人体直立姿势的平衡起着重要作用。这一观察是用来激发调查的一个简单的开关式控制器的姿势摇摆，其中只有当垂直位移角超过一定的阈值时，才进行纠正运动。这种机制被证明是一致的实验观察到的变化，在两点相关的人体姿势摇摆。对该模型的首次通过时间的分析表明，这种控制策略可以利用随机不稳定的一阶延迟微分方程的两个内在性质来减缓逃逸：（i）时间延迟和（ii）动力学可以“暂时限制”在原点附近的可能性。
Experimental observations indicate that positive feedback plays an important role for maintaining human balance in the upright position. This observation is used to motivate an investigation of a simple switch-like controller for postural sway in which corrective movements are made only when the vertical displacement angle exceeds a certain threshold. This mechanism is shown to be consistent with the experimentally observed variations in the two-point correlation for human postural sway. Analysis of first-passage times for this model suggests that this control strategy may slow escape by taking advantage of two intrinsic properties of a stochastic unstable first-order delay differential equation: (i) time delay and (ii) the possibility that the dynamics can be 'temporarily confined' near the origin.