Study On Vehicle Electromagnetic Environment Calculation Method In Engineering Project

With the development of electronic technology, the integration of vehicle electronicdevices become more sophisticated, resulting in its lower levels of anti-electromagneticsensitivity. If longer be effected by a nuclear explosion or the strong electromagnetic pulseattack from electromagnetic bombs, the sensitive equipments may easily damage evenparalysis. The complex electromagnetic environment has become one of the importanthazards of vehicle safety. Therefore, there is an urgent need to carry out environmentaleffects of vehicle systems and give a set of engineering calculation method ofelectromagnetic environmental effects which can work out the important parameters of theelectromagnetic environment quickly, accurately and effectively. As a basis, we can protectthe vehicle electronic control system and ensure their normal operation.The complex electromagnetic environment, especially the field formed by strongmagnetic pulse, exerts a significant effect on the vehicle. Firstly, the paper classifies andsummarizes the electromagnetic pulse, analyzes and compares the characteristics of threetypical electromagnetic pulse, and studies the coupling path of electromagnetic pulse intothe vehicle; Secondly, depending on the difference of propagation distance, the paperanalyzes the propagation of electromagnetic waves, calculates the electromagneticenvironment both in high-altitude and near the ground. And then uses HEMP, HPM andUWB as the pulse sources, simulates the vehicle electromagnetic environment with CSTMS software; Finally, the paper analyzes electromagnetic pulse coupling through carwindows, estimates the average electric field strength and the distribution inside the car, andclouds over two hundred observation points in typical vehicle to simulate theelectromagnetic environment.The main contributions are as follows:(1) The paper analyzes the spatial propagation characteristics of electromagnetic waves.Using differential ideological, it make the spherical wave near the ground equivalent to the plane wave. Using ground electromagnetic wave reflection and superposition principle, itproposes the method to calculate the electromagnetic environment in high-altitude and nearthe ground.(2) The paper works out the electromagnetic environment outside the vehicle withtypical sources of electromagnetic pulses through simulation. Considering the impact ofpolarization direction, incident angle, height from the ground and soil characteristics of theelectromagnetic environment outside the vehicle. The results of simulation reveal thatelectromagnetic environment outside the car is the most severe when the polarizationdirection is90°, the incident angle is30°, the height from the ground is0m and the soil isclay or organic wetlands. This conclusion provides theoretical support for electromagneticprotection of vehicles.(3) According to the power balance theory and statistical characteristics, anapproximate formula is presented for calculating the average electric field strength insidethe car. It can calculate the average electric field strength inside the cab and intensityprobability distribution through the electric field strength outside the car, the area ofwindows and the center frequency of the pulse source. This method using only threeparameters can be calculated the important parameters of electromagnetic environmentinside, so it is simple and universal.(4) Using CST software as simulation platform, clouding215observation points in thecab, simulation gets the interior electromagnetic environment effected by broadband HPMpulse source. The paper analyzes the electromagnetic environmental information ofsensitive points and establishes a database of electromagnetic environment inside thevehicle. By comparing average electric field strength inside the vehicle, the electric fieldintensity distribution obtained between simulation and the results of estimation methods, itsummarizes the regular pattern of the inside electromagnetic environment and verifies thevalidity of estimation methods.(5) The paper developed two software which can measure the electromagneticenvironment outside and inside the vehicle respectively. They contain a typicalelectromagnetic pulse source database and the information about the electromagneticenvironment of sensitive points inside the vehicle. Two software can work out the effectiveinformation about vehicle electromagnetic environment with simple parameters, meeting thesimple, rapid calculation, real-time engineering needs.