采用小波分析法的立靶测量系统时间计算方法

Time calculation method base on wavelet analysis in vertical target measurement system

在立靶测量系统中,针对弹丸作用光幕时探测电路输出信号的不一致,导致传统的弹头触发和弹尾触发方式提取光幕时间值存在较大的测时误差问题,提出了利用计算机采集光电探测靶的输出信号,采用小波变换模极大值方法,检测弹丸穿越光幕时产生的信号突变点奇异位置,计算信号突变起始点之间的采样点数,结合采集系统的采样率,推算出弹丸作用于光幕间的时间值。根据四光幕交汇的测量原理,分析各光幕间的时间值与立靶坐标的关系。基于小波变换理论,分析小波变换模极大值检测弹丸信号奇异位置的原理,研究立靶测量系统的时间计算算法。在4 m×4 m的靶面,采用小波分析方法计算的坐标值与传统方法计算的坐标值与纸靶对比,平均误差值减小近6 mm。结果表明:小波分析法具有明显的优越性,提高了立靶测量系统的测量精度。

In the vertical target measurement system, time data can be gained by the trigger method of projectile nose and projectile bottom, because the detection performance of optic-electric detection vertical target is different, it makes the output signals differ in every detection screen. To solve these problems, the computer was used to gather the signal when projectile passing the detection screens, wavelet transform modulus maxima was applied to detect the projectile signal mutation position, and these mutation positions were used to dispose and calculate the time value between screens base on system sampling rate. According to the principle of four screens across, the relation of time value and vertical target coordinates was analyzed. Base on wavelet transform theory, the principle that wavelet transform modulus maxima detected projectile signal singularity position was analyzed, and the time calculation arithmetic of vertical target measurement system was studied. Through experimentation, the average error value of coordinate can reduce 6ram compared with the traditional method in detection area 4 m×4 m. The result shows that the method of wavelet analysis can improve measurement precision.