| With the application and promotion of high and new technologies in modern weapons and equipment,war is developing in a three-dimensional and synthetic direction,which makes the electromagnetic environment in the battlefield more complex.As a major military transportation tool,special vehicles are more closely connected with microelectronics technology,and their automation and intelligence have been greatly improved.However,due to the complex electromagnetic environment in the battlefield,when special vehicles are used,The external electromagnetic pulse enters the interior of the vehicle body through the vehicle body aperture or vehicle antenna coupling,acting on the internal electronic components of the electronic control unit(ECU)of the vehicle,causing loss of ECU function and affecting the normal driving of the vehicle.Therefore,it is of great significance to study and analyze the electromagnetic compatibility of the engine ECU system.Based on the particularity of the complex battlefield electromagnetic environment of special vehicles,this paper uses High Altitude Electromagnetic Pulse(HEMP)to study the effects of radiation interference and coupling interference on the engine ECU of a military special vehicle.Corresponding protective measures are taken for the housing,connectors,and connecting cables of the engine ECU,and the shielding effectiveness before and after protection is compared and verified,The main work is as follows:(1)Taking a military special vehicle as the research object,the electromagnetic leakage caused by the window and heat dissipation grille in the body structure was studied,and the electromagnetic environment in the engine compartment was analyzed.On this basis,the analysis model of vehicle engine ECU is established,and the electromagnetic leakage of different pore structures under electromagnetic irradiation is analyzed.The results show that under the same area conditions,electromagnetic leakage is related to the maximum linear size of the engine ECU connector hole seam,and it continues to deteriorate with the increase of the maximum linear size.(2)In the electromagnetic environment of the entire vehicle,the induced voltage of the conductive cable in the cabin at the port under electromagnetic pulses was studied,and based on this,the effects of irradiation direction,E-field polarization angle,and incident angle on its radiation sensitivity were further analyzed,and the electromagnetic compatibility characteristics of the cable layout inside the vehicle were analyzed;(3)The shielding effectiveness of the ECU housing after shielding measures such as using metal connectors and laying wave absorbing materials inside were studied,and the improvement of shielding effectiveness of the housing by different shielding measures was compared and analyzed.At the same time,the induced voltage and induced current at the terminals of four different cable types under electromagnetic pulses were studied.The protective performance of different cable types was compared and analyzed,and the optimization measures for the electromagnetic interference protection ability of the engine ECU were summarized.(4)The impact of three grounding methods,single point,multi-point,and suspension grounding,on the electromagnetic protection ability of vehicles is analyzed.The protection effect of external power filter is verified through on-board equipment experiments.Finally,the weak points of electromagnetic protection of the vehicle body are monitored through vehicle EMC testing.Through the research on the above content,a set of highly applicable electromagnetic radiation simulation modeling methods for ECU housing has been obtained,which clarifies the improvement effect of ECU housing,metal connectors,wave absorbing materials,and shielding cables on electromagnetic protection capabilities.Therefore,the research in this article has certain reference value for electromagnetic pulse protection of engine ECU. |
