Research On Fast Identification Technology Of Laser Screen System

Laser Screen System has an extremely important role on low ballistic target test, it has a negative impact on fast identify the target, while the target signal is weak or there is interfering object. This thesis studies the approach of identifying whether some object crosses the laser screen, eliminating the interference and gets the influence of distribution characteristics of laser energy of laser screen different position on fast identification of target, combining with designing the circuit to verify the method above. Those studies have great significance on further enhancing performance and the applied area of Laser Screen System.Firstly, statistic characteristic of noise of output static signal is studied, threshold rule based on the result is derived, through which the object that crossing the laser screen is identified. Judging by the width of analog target signal, the target signal is identified on single laser screen. The joint-identify method that based on four laser screen is designed in this thesis, and the concrete implementation measure is formulated. Secondly, Wavelet transform is used to identify the target analog signal, the differences about different wavelet functions on addressing target signal is analyzed, and Gauss Wavelet functions is selected, by comparing the smoother of Wavelet coefficient in different decomposition layers, which has a significant effect on target identification, a fast algorithm for target signal identification is established, with seventh layer Wavelet coefficient is choice to identify the target signal. Target analog signal is collected by PCI-50614 high-speed collection card, and analyzed by Wavelet transform, as a result, the target signal is fast identified. Thirdly, Laser energy distribution characteristic of laser screen is studied, which has an obvious influence on the identification of target. The mathematical model of the laser screen energy distribution was established, and the influences about laser energy intensity on the target signal fast identify are got, and the definitive detection area of laser screen is obtained. At last, the hardware circuit is designed on the basis of the simulation experiment, which is used to verify the method of identification target.The results of experiments show that the 5δ threshold rule which based on noise statistical characteristic can identify target signal, and faster than the empirical threshold method. Wavelet transform on the analog signal processing can achieve the identification of target signal. The experimental methods partly achieve the goal of fast identification of the target, and the results of the thesis have certain theoretical and practical application value.