频率锁定对伞弹系统稳态特性的影响

旋转伞弹在下落过程中的稳定性直接影响着子弹的扫描性能,因此研究影响伞弹系统稳定性的因素非常重要.采用激光双目立体投影图像视觉技术在立式风洞中非接触测量了伞弹模型的扫描角和瞬时转速,介绍了测量与数据处理的方法,着重讨论了频率锁定现象对伞弹系统稳定扫描特性的影响.试验结果显示:在较窄风速范围内,存在频率锁定区域；在频率锁定区,扫描角和瞬时转速具有较好的周期稳定性,对外界的干扰不敏感,能量谱峰值也较显著.

The influence of lock-in frequency to the stably scanning performance of parachute-bomb system

The stability of spinning parachute-bomb in the falling time directly affects the scanning performance of the bomb,so it is important that the parachute-bomb’s stability is investigated.The scanning angle and instantaneous rotate speed of the parachute-bomb in vertical wind tunnel were measured using binocular stereo vision technology in the paper.The measuring and data processing methods were introduced.This paper focused on the influence of lock-in frequency on the stably scanning performance of parachute-bomb system.The results show that in the narrow range of wind speed,the area of lock-in frequency exists;in this area,the scanning angle and instantaneous rotate speed have good periodic stability,and are insensitivity to perturbing from outside and higher peak power spectrum.