Laser Proximity Fuze Signal Processing Technology Based On DSP

Laser proximity fuze has been widely applied in military domain. With thedevelopment of weapons and the complication of the modern battlefield, higherprecision of the laser proximity fuze with higher performance was demanded. Wedesigneda hardware platform based on DSP(DigitalSignal Processor) to processobject echo signals, and investigated methods to improve the precision of thelaser proximityfuze by using digital signal processing.The concept of the software laser proximity fuze and the project of themodularized design for software laser proximity fuze were proposed byreferencing the idea of software radio in communication system. And thehardware platform with the sampling rate 100MHz based on the TMS320VC5502chip was designed and constructed. Compared with the conventional systems forsignal processing, the hardware platform we designed has the merits of concisionand modularization, which facilitates the upgrading of laser proximity fuze andshortens thedesigning time of laserproximityfuze system.A mathematical model of a quasi-Gaussian lasering pulse based on theanalysis of thetransmitter oflaser proximity fuze was presented. The broadeningand distortion of echo pulse caused by the slope, reflectance and the size ofeffected area of the object were discussed. At last, several emulate echoes for thetypicalobjects were presented.According to the emulation results for the analog processing and the digitalprocessing, it was shown that the errors of the digital processing were smallerthan that of the analog processing. Basing on the centroid algorithm which hadthe smallest error in the digital processing, we put forward a"double-scale"centroid algorithm. At sampling rate of 1GHz, SNR of 8db and the range of 45m,the emulating error of the"double-scale"centroid algorithm was 0.45m. Thisvalue is lower to about tenth of that in the analog processing. The testing resultsof the"double-scale"method on the development board based on DSP were thesame with the emulatorwhen we adopted datas as the sampling rate was 1GHz.At last, principle experiments based on the hardware platform were performedby collecting and digitalprocessing of echo waveforms. The results indicates that the"double-scale"centroid algorithm can anti-interference the wobbling of theecho amplitude or noise, but the width of the pulse influences the results of thisalgorithm. At the range of 45m, the error of"double-scale"centroid algorithmwas 4.5m.The results of the emulation and the principle experiments indicated that it isfeasible for the project based on the hardware platform we designed and the"double-scale"centroid algorithm to process echo signals in the laser proximityfuze.