Electromagnetic Susceptibility Assessment Of Vehicle Engine Ignition System

High power microwave weapons are the most important type of electromagnetic pulse weapons,which can be used in electronic countermeasures to destroy the enemy’s vehicle mobility and change the course of war.Therefore,it is important to study the EMP effect of key components of vehicle engine ignition system,evaluate the susceptibility of ignition system under the effect of high power microwave irradiation and analyze the probability of electromagnetic failure of vehicle ignition system.Aiming at the problem of sensitive failure of vehicle ignition system under multiple attacks of high-power pulse weapons,this paper takes the direct ignition system of a civilian off-road vehicle as the research object,calculates the random electromagnetic stress situation to which the system components are subjected through electromagnetic simulation,uses the means of test to obtain the electromagnetic susceptibility threshold data of the system components,establishes the susceptibility assessment model,and calculates the failure probability of the ignition system under the single and multiple actions of high-power microwave.The main contents and contributions of the paper are as follows:(1)Calculation of the electromagnetic environment of the ignition system under the action of high power microwave irradiation.Based on the transmission line matrix algorithm,the CST electromagnetic simulation software is used to calculate the spatial field strength of the ignition system under the action of high-power microwave and the distribution pattern of the coupling voltage on the interconnection cable of the system,which provides data support for the subsequent evaluation of the electromagnetic sensitivity of the ignition system.(2)A sensitivity test platform for key components of the engine ignition system was built and electromagnetic susceptibility effect tests were conducted.For the problems of abnormal ignition moment or direct flameout of ignition system,the coupling injection susceptibility test of two types of position sensors and cables on the ignition was carried out,and the corresponding susceptibility threshold data were obtained,and the cumulative distribution function and probability density function were fitted and calculated.(3)A hierarchical bayesian network based evaluation of the electromagnetic sensitivity of vehicle ignition systems under single or multiple actions of high power microwaves is carried out.The evaluation model of ignition system is established by integrating electromagnetic topology theory and interaction sequence diagram with hierarchical bayesian network;The stress-strength interference model is applied to calculate the failure probability of system components under single or multiple pulse irradiation,and the conditional probability of model nodes is given by using three scale analytic hierarchy process combined with expert experience;The failure probability of engine ignition system under single or multiple irradiation of high power microwave is calculated.The probability of engine ignition system failure under single or multiple irradiation is calculated.