Initial phase and frequency modulations of pumping a playground swing
Initial phase and frequency modulations of pumping a playground swing
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操场秋千的初始相位和频率调制
DOI：
10.1103/physreve.107.044203
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发表时间：
2023
影响因子：
2.4
通讯作者：
M. J.
中科院分区：
文献类型：
--
作者：
Hirata;C.;Kitahara;S.;Yamamoto;Y.;Gohara;K.;& Richardson;M. J.
操场秋千是一个动态的，耦合的振荡器系统组成的秋千作为一个对象和一个人作为摇摆。在这里，我们提出了一个模型，用于捕获的效果的初始阶段的自然上身运动上的连续泵的秋千和验证此模型从运动数据的10个参与者泵秋千的三个不同的摆动链长度。我们的模型预测，如果最大后倾阶段（我们称之为初始阶段）发生在挥杆处于垂直（中点）位置时，并且在振幅较小时向前移动，则挥杆泵送最多。随着振幅的增长，最佳初始阶段逐渐向周期的早期阶段转移，即挥杆轨迹的后端。正如我们的模型所预测的那样，随着摆动幅度的增加，所有参与者的上身运动的初始阶段都提前了。这表明，摇摆人调整频率和他们的上身运动的初始阶段，以成功地泵操场摆动。
The playground swing is a dynamic, coupled oscillator system consisting of the swing as an object and a human as the swinger. Here, we propose a model for capturing the effect of the initial phase of natural upper body motion on the continuous pumping of a swing and validate this model from the motion data of ten participants pumping swings of three different swing chain lengths. Our model predicts that the swing pumps the most if the phase of maximum lean back, which we call the initial phase, occurs when the swing is at a vertical (midpoint) position and moving forward when the amplitude is small. As the amplitude grows, the optimal initial phase gradually shifts towards an earlier phase of the cycle, the back extreme of the swing's trajectory. As predicted by our model, all participants shifted the initial phase of their upper body movements earlier as swing amplitude increased. This indicated that swingers adjust both the frequency and initial phase of their upper body movements to successfully pump a playground swing.