Understanding how dexterity improves with practice is a fundamental challenge of motor control and neurorehabilitation. Here we investigate a ball and beam implementation of a dexterity puzzle in which subjects stabilize a ball at the mid-point of a beam by manipulating the angular position of the beam. Stabilizability analysis of different biomechanical models for the ball and beam task with time-delayed proportional-derivative feedback identified the angular position of the beam as the manipulated variable. Consequently, we monitored the changes in the dynamics with learning by measuring changes in the control parameters. Two types of stable motion are possible: node type (nonoscillatory) and spiral type (oscillatory). Both types of motion are observed experimentally and correspond to well-defined regions in the parameter space of the control gains. With practice the control gains for each subject move close to or on the portion of the boundary which separates the node-type and spiral-type solutions and which is associated with the rightmost characteristic exponent of smallest real part. These observations suggest that with learning the control gains for ball and beam balancing change in such a way that minimizes overshoot and the settling time. This study provides an example of how mathematical analysis together with careful experimental observations can shed light onto the early stages of skill acquisition. Since the difficulty of this task depends on the length of the beam, ball and beam balancing tasks may be useful for the rehabilitation of children with dyspraxia and those recovering from a stroke.

中文翻译：

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为学习过程建立度量标准和控制律：球和梁平衡。

了解如何通过练习提高敏捷度是运动控制和神经康复的一项基本挑战。在这里，我们研究了灵巧难题的球和梁实施方式，其中受试者通过操纵梁的角位置将球稳定在梁的中点。具有时滞比例微分反馈的球和束任务的不同生物力学模型的稳定性分析将束的角位置确定为受控变量。因此，我们通过测量控制参数的变化，通过学习监控了动力学的变化。两种稳定的运动是可能的：节点型（非振荡）和螺旋型（振荡）。两种类型的运动都通过实验观察到，并且对应于控制增益的参数空间中定义明确的区域。在实践中，每个对象的控制增益接近或在边界的一部分上移动，该边界将节点型解和螺旋型解分开，并且与最小实部的最右边特征指数相关。这些观察结果表明，通过学习球和梁平衡的控制增益，可以使过冲和稳定时间最小化。这项研究提供了一个示例，说明数学分析与仔细的实验​​观察如何可以揭示技能培养的早期阶段。由于这项工作的难度取决于光束的长度，