众所周知,秋千之所以能越荡越高,是由荡秋千者通过秋千在最大摆角时身体的下蹲和过平衡位置时身体的上升来实现的。秋千每来回荡一次,人体重心上升和下降各两次,使系统获得了额外能量输入,从而使秋千摆幅不断增大,这就是秋千非线性参变共振。 It is well-known that the reason why the swings can swing higher and higher is achieved by the swinging persons’ body ascending and squatting at the maximum swings and over the balance position. Swing every time once again, the human body center of gravity rise and fall twice, the system gained additional energy input, so that the swing swing increasing, which is the swing nonlinear parametric resonance.