弹丸穿过倾斜梯形光幕特征时刻修正算法研究

Feature Moment Acquisition Correction Algorithm of a Projectile Passing Through Incline Trapezoidal Screen

传统的幕中触发法在计算过幕时刻时是将光幕沿厚度方向的分布理想化为矩形,实际光幕由于镜头成像原理,其厚度呈梯形分布。当光幕之间存在夹角或弹丸斜入射光幕时会引入过幕时刻的提取误差。基于光幕探测器输出信号的幅值与弹丸在光幕中的位置呈线性对应关系,提出了一种弹丸穿过倾斜梯形光幕特征时刻修正算法。通过对光幕厚度的分析,采用迭代修正算法计算出半峰值点和弹道线与光幕中心面交点的时间差,得到弹尾到达光幕中心面的准确时刻。实弹射击表明,修正算法提取过幕时刻精度平均提高7.9%,可以直接用于六光幕天幕立靶测量系统。

The traditional mid-screen trigger method idealizes the distribution of the screen along the thickness direction into a rectangle in calculating the feature moment, and the actual sky-screen thickness is trapezoidal due to lens imaging principle. Acquisition error will be introduced when there is an angle between the screens or projectile oblique incidence to the screen. Based on the linear relationship between the amplitude of the output signal of the screen detector and the position of the projectile in the screen, a correction algorithm for the time of the projectile through the slant trapezoidal screen is presented in this paper. A feature moment acquisition algorithm of projectile passing through incline trapezoid- al screen is put forward. Through the analysis of the thickness of the screen, the iterative correction algorithm is used to calculate the time difference between the half-peak point and the intersection of the ballistic line and the center plane of the screen. The accurate moment of the tail point reaches the central plane is gotten. The method is verified by the real projectile tests. The accuracy of the algorithm is improved by 7. 9%, which can be used in six-light-screen array sky screen measurement system directly.