| During the secondary detonation of fule air explosive(FAE)explosion,the detonating time of the fuze often exhibits a large time deviation or even misfires,and the interference caused by the electromagnetic radiation of the explosion has begun to receive attention.To study the influence of explosive electromagnetic radiation on fuze and improve the anti-interference ability of fuze in explosive electromagnetic environments,it is necessary to understand the characteristics and laws of explosive electromagnetic radiation.At present,the research objects of explosive electromagnetic radiation are basically small equivalent explosives,and research data on large equivalent explosives and high-energy warhead explosive electromagnetic radiation are lacking.The electromagnetic radiation generated by an explosion is affected by various complex factors.Its generation mechanism has not yet formed a complete theoretical model,and its research purpose cannot be achieved only by simulation methods.Measurement and signal analysis are still necessary research methods.The measurement conditions of the explosion field are relatively complex,and there are many interference factors in the explosion process of high-energy warheads.Therefore,it is necessary to design an electromagnetic radiation measurement system and conduct research on measurement methods in an explosion field environment.The characteristics of explosion electromagnetic radiation signal are significantly different from those of the modulated electromagnetic signal.Traditional electromagnetic signal analysis methods are not suitable for analyzing explosion-induced electromagnetic signals.Therefore,it is necessary to study the analysis and processing methods for explosion-induced electromagnetic radiation signals.Based on the above considerations,explosion electromagnetic radiation is considered as the research object,and research work on relevant characteristic law analysis,measurement technology,signal analysis methods,fuze electromagnetic sensitivity analysis,and anti-interference is conducted.The main work of this paper is as follows:(1)Aiming at the problem that the current research on explosion electromagnetic radiation focuses on the small equivalent explosive explosion measurement and lacks the conclusion of the regularity of the warhead explosion electromagnetic radiation,the change law of the explosion electromagnetic radiation is analyzed by means of numerical simulation,literature comparison,experimental measurement,etc.The results show that the numerical simulation method can predict the measurement results of the explosive explosion electromagnetic radiation;however,the simulation results do not match the warhead explosion measurement results,which highlights the necessity of the warhead explosion electromagnetic measurement.Combined with the factors that influence the electromagnetic radiation of the explosion on the fuze,the space,time domain,frequency domain,and energy characteristics of the electromagnetic radiation of the explosion are correlated,and a comprehensive analysis method is discussed to provide ideas for the analysis method of the electromagnetic sensitivity of the fuze.Through in-depth analysis of the generation mechanism of explosion electromagnetic radiation and the characteristics of the radiation source field,it is concluded the conclusion that the explosion plasma temperature and electromagnetic intensity have a strong correlation,and the division conditions of the explosion radiation field are obtained,which provides a theoretical basis for the measurement method and signal analysis method of explosion electromagnetic radiation.(2)To conduct research on fuze anti-explosion electromagnetic interference,it obtains the detailed parameters of electromagnetic radiation of the fuze working environment,and designs the testing antenna,signal conditioner,RF coaxial line,repeater,and other instruments.Finally an electromagnetic radiation measurement system has been established.Owing to the wide range of test frequency bands,large signal amplitude changes,easy overloading of data acquisition instruments,large signal transmission loss,and other problems of large equivalent explosive and warhead explosion electromagnetic radiation,the measurement system can meet all indicators of high-energy warhead explosion electromagnetic radiation measurement by adopting technical means,such as mixing band antenna combination(1.5 MHz～8.5 GHz),highprecision coefficient adjustment,multifunctional signal conditioning,and signal transmission attenuation compensation.In view of the measurement conditions of the blast field and the interference factors in the process of warhead explosion,a method of measuring point layout,instrument installation,and protective improvement measures is proposed;thus,the measurement system can effectively prevent the impact of factors such as the coupling interference of the shock wave and the explosion electromagnetic pulse in the blast field,improve the quality of the sampling signal,avoid the omission of the sampling signal,and form an electromagnetic radiation measurement method suitable for the environment of a highenergy warhead blast field.(3)Aiming at the characteristics of explosion electromagnetic radiation signals,such as large amounts of data,nonperiodicity,unstable changes,and reflected signal interference,an efficient and comprehensive signal processing process was established to extract key characteristic parameters from typical explosion electromagnetic signals.The analysis shows that the rising edge range of the explosion electromagnetic signal is 8～50 ns,with a minimum pulse interval of 0.002 ms.The time-frequency characteristics of the explosion electromagnetic signal were analyzed to compensate for the shortcomings of the traditional electromagnetic signal spectrum analysis method,and an accurate analysis of the spectrum distribution of the explosion electromagnetic radiation signal was realized.The energy-concentration frequency band of the explosion electromagnetic signal is highly coincident with the sensitive frequency band of the fuze(2～500 MHz).By analyzing the hierarchical time sequence structure of explosion electromagnetic pulses based on electromagnetic pulse train coding and model reconstruction technology,a calculation method for measuring the density of explosion electromagnetic pulses was proposed.Aiming at the problem that the electric field strength and signal power cannot directly represent the energy of the explosion electromagnetic radiation,combined with the measured value of the surface temperature of the explosion fireball,the plasma energy is introduced as the electric field strength correction parameter,and the analysis method of the explosion electromagnetic radiation energy is improved by calibrating the damage ability of electromagnetic radiation.(4)To accurately analyze the sensitivity of the fuze in an explosive electromagnetic environment,based on the characteristics of the explosive electromagnetic radiation signal,an explosive electromagnetic pulse simulation experimental system and an equivalent experimental method of the electromagnetic radiation interference of the fuze are designed,and an interference measurement of the explosive electromagnetic radiation on the fuze under laboratory conditions is realized.The interference coefficient is quantitatively expressed by the interference index of the explosion electromagnetic radiation,and the fuzzy analytic hierarchy process is used to organically combine all the factors affecting the explosion electromagnetic radiation on the fuze.An explosion electromagnetic radiation interference model is established based on the test data.The reliability of the electromagnetic sensitivity analysis method is verified by using the compatibility index test method.An electromagnetic pulse protection method is proposed based on the analysis of the electromagnetic radiation sensitivity of the fuze,and it strengthens the anti-explosion electromagnetic interference measures of the secondary detonating fuze of the FAE explosions.The electromagnetic sensitivity of the fuze can be reduced from level V to level I. |
PDF Full Text Request