By the concept of the centreofmotion, an accurate expression for tether tension is derived and used in determining frequencies.
由绳系卫星系统运动中心概念推导出的每小段系绳张力的平均值，被用于系统振动频率的求解。
2
According to theorem ofmotionofcentre of mass and theorem of moment of momentum about centre of mass, we derive the theorem of moment of momentum about instantaneous center of rotation.
从质心运动定理和相对质心的动量矩定理出发，导出了相对瞬心的动量矩定理。
3
Besides, the characteristics with varying pitch and separation on hole centreof chain plate and the mechanism for uniform motion of drive is probed.