sling movement

The model mainly includes the boom luffing, rotating, and sling lifting movement.

模型中主要涉及臂架的变幅、回转以及吊索的起升运动。

The results show that to make the seed to do sling movement, the index D of sling must be larger than 1 and usually its range is from 1.4 to 3.3. The radical frequency of stimulating vibration has a lower limit.

结果表明：要使种子产生抛掷运动必须使抛掷指数D≥1，一般取为1.4~3.3；同时激振基频有一下限值；

A system simulation model of heavy cargo airdrop system is build, which includes the whole process of cargo movement inside and outside of plane and the trajectory of parachute during its deployment and inflation. New simulation methods about parachute cluster and multi-sling system are developed.

建立了货物空投系统仿真计算模型，包括货台在舱内和舱外全过程的运动特性、降落伞拉直和充气过程的轨迹特性计算等，提出了伞群模拟和多吊带系统分析的新方法。