膛内旋转弹丸微运动建模研究

Research on Micro-motion Modeling of Rotating Projectiles in Bore

针对弹丸膛内运动姿态测试的问题,建立弹丸在线膛炮膛内运动的微多普勒模型,采用短时傅里叶变换(STFT)、Wigner-Ville分布和Hilbert-Huang变换三种时频分析方法对弹丸回波信号进行分析。研究结果表明:若是获取纵向运动信息,STFT处理微多普勒能量占比小的膛内运动弹丸回波信号的精度最高,曲线平滑;若是获取微运动信息,对于微多普勒能量占比大的弹丸回波信号,使用Hilbert-Huang变换和Wigner-Ville分布效果好,其中Hilbert-Huang变换得到的瞬时频率信息更加精准、误差更小。

Aiming at the problem of motion attitude test of projectile in bore,movement posture of the projectile inside the ball is an important part of the internal ballistic testing.A micro-Doppler model of projectile micro-motion in a rifled barrel is established.The short-time Fourier transform(STFT),Wigner-Ville transform and Hilbert-Huang transform are used to analyze the projectile echo signals.The result of research shows that when extracting the longitudinal motion information,STFT has the highest accuracy of the echo signal of the micro-Doppler energy occupying ratio and the curve is smooth.If it is necessary to obtain micro-motion information from it,for a projectile echo signal with a large proportion of micro-Doppler energy,using Hilbert-Huang transform and Wigner-Ville transform method is effective.The instantaneous frequency information obtained by Hilbert-Huang transform method is more accurate and the error is smaller.