The 'extrapolated center of mass' concept suggests a simple control of balance in walking
The 'extrapolated center of mass' concept suggests a simple control of balance in walking
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DOI：
10.1016/j.humov.2007.08.003
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发表时间：
2008-02-01
影响因子：
2.1
通讯作者：
Hof, At L.
中科院分区：
文献类型：
--
作者：
Hof, At L.
在整个身体质心（CoM）的位置x和速度v旁边，可以引入“外推质心”（XcoM）： zeta = x + v/omega(0)，其中omega(0)是与身高相关的常数。基于倒立摆平衡模型，XcoM能够以相对简单的形式制定稳定行走的要求。在一个非常简单的行走模型中，忽略脚翻滚的影响，XcoM的轨迹是一系列直线，在脚接触时从压力中心（CoP）指向XcoM。CoM以更正弦的轨迹跟随XcoM。一个简单的规则就足以保证稳定的行走：在脚的位置上，CoP应该被放置在XcoM后面和外面一定距离的地方。在实践中，这意味着导致CoM速度变化Delta v的干扰可以通过脚位（CoP）在相同方向上等于Delta v/(0)的变化来补偿。类似的简单规则也可以用于启动、停止和转弯。(C) 2007 Elsevier B.V.版权所有
Next to position x and velocity v of the whole body center of mass (CoM) the 'extrapolated center of mass' (XcoM) can be introduced: zeta = x + v/omega(0), where omega(0) is a constant related to stature. Based on the inverted pendulum model of balance, the XcoM enables to formulate the requirements for stable walking in a relatively simple form. In a very simple walking model, with the effects of foot roll-over neglected, the trajectory of the XcoM is a succession of straight lines, directed in the line from center of pressure (CoP) to the XcoM at the time of foot contact. The CoM follows the XcoM in a more sinusoidal trajectory. A simple rule is sufficient for stable walking: at foot placement the CoP should be placed at a certain distance behind and outward of the XcoM at the time of foot contact. In practice this means that a disturbance which results in a CoM velocity change Delta v can be compensated by a change in foot position (CoP) equal to Delta v/omega(0) in the same direction. Similar simple rules could be formulated for starting and stopping and for making a turn. (C) 2007 Elsevier B.V. All rights reserved.