Research On Electromagnetic Analysis And Protection Strategy Of Car Engine ECU

With the continuous development of modern science and technology,the degree of integration of automotive internal electronic products is getting higher and higher.As the electronic control unit of driving computer is the core part of vehicle control,its electromagnetic compatibility requirements are increasing day by day.On the one hand,it is easy to produce crosstalk because of the wide variety of electronic equipment in the car,dense deployment and many wiring harnesses.On the other hand,it is because of the increasingly complex external electromagnetic environment and some man-made interference will affect the engine ECU and threaten driving safety.The electromagnetic analysis of car engine ECU is the premise of electromagnetic protection strategy,which plays a vital role in improving car driving safety.For test and simulation method,this paper focuses on the coupling and irradiation effects on engine ECU,based on the two types of interference,the engine ECU,connecting wiring harness connector,shell of electromagnetic shielding,and verify its protective effect,the results show that the protective shielding efficiency were increased after the engine ECU,connecting wire of the electromagnetic shielding ability increase obviously,Demonstrate the feasibility of the protection plan.The influence of coupling interference and irradiation interference on engine ECU is analyzed.The results show that when the coupling interference voltage is between3.9k V and 4.1k V,the input signal of engine ECU is in an unstable state and occasionally disturbed.When the voltage is above 4.1k V,the input signal of engine ECU will be interfered.The shielding efficiency of engine ECU is reduced by irradiation interference,and resonance occurs at many frequency points,which affects the normal operation of engine ECU.Based on this,the electromagnetic protection scheme of the engine ECU is proposed.Based on the rectangular cavity engine ECU model,the disturbance of the connector position,the center position of the cavity,the left and rear positions,the right and rear positions of the engine ECU and the connecting wiring harness are quantitatively analyzed.According to the analysis results,electromagnetic shielding,wave absorption and grounding are used to protect the ENGINE ECU.After protection,the shielding efficiency of different positions inside the engine ECU is improved to varying degrees.For example,the shielding efficiency of connector position is increased by about 15.4d B.The electromagnetic protection ability of the engine ECU connecting wire harness is improved obviously,and the peak-to-peak value of the induced voltage on the wire harness is reduced by about 1000 times after protection,which proves the feasibility of the protection scheme.