High-speed Missile Target Recognition Technology Based On Quasi-electrostatic Field Detection

It is well known that laser detector is commonly used as detection unit in activeprotection system. With the development of anti-armor weapons, it needs to react inthe work area which is about1m away from target so that the system effectivelyprotects anti-armor projectile which velocity is higher than1000m/s. This requiresvery short reaction time for detection. The laser system is difficult to quickly andaccurately measure such motion parameters of high-speed projectile targets asdistance and speed, while the capacitance detection with mature technology can do itwell. So the capacitance short-range detection is a good choice for our research.This paper discussed the level of sensitivity of capacitance detection based onquasi-electrostatic field and analyzed the theory of capacitance detector. This paperdesigned detection circuit based on capacitance fuze and analyzed the effect ofelectrodes with different sizes to the sensitivity of capacitance detector, and alsodesigned and optimized parameters of detection circuit. After that, this paper designedsignal processing circuit to get the variation and variation rate of detector circuitwhich constitute the target characteristics in missile-detector encounter. The signalprocessing circuit also magnified amplitude of signal and effectively limited highfrequency noise. A/D acquisition circuit was designed to transform analogy signal into12bits binary output code. We sent the12bits binary code to FPGA signal processingcircuit before matching the voltage value of high and low. This paper analyzed theoutput voltage of detection circuit of a capacitance detector. It can be found that, whena high-speed target getting close to the detector, the output voltage of detection circuitchanges with certain rules. Our research applied a low-speed static test to obtain thestatic characteristic data of the target, proposing a high-speed target recognitionalgorithm and setting threshold values based on starting voltage, second derivativeand signal duration.Isim simulation result showed that the algorithm was effective to recognizehigh-speed missile target. Experiments were made to test the effectiveness of thewhole system. The velocity of missile was tested. The data was recorded into aNAND Flash which was controlled by FPGA chip. The experiment data demonstratedthat the high-speed missile could be recognized by the whole system, when it gettingclose to the detection system in different orientations.