Aircraft Fuel Measurement System Electromagnetic Interference Study

Fuel quantity measurement is a main task in A/C fuel system design. It's unction is to measure and indicate residual fuel in the aircraft. The precision and reliability of the FQMS has great influence on the aircraft performance. High precision of FQMS may improve payload, range and action radius of A/C. It has great significance for A/C air combat, weapon emission, navigation, flight control. There are many factors to lower the measurement precision. Besides the malfunction of FQMS itself, electromagnetic interference (EMI) is a important cause.The article introduces the source, spread passage and operation theory of EMI, the development of electromagnetic compatibility (EMC), as well as the working principle and composition of A/C FQMS. Investigation on the EMI problem of a certain model A/C FQMS is made in the article. Through analysis of interference function, to confirm the interfering source and coupling path, simulate the failure phenomena by way of examination, and then figure out the settling methods, such as screen, filter and lower the amplifying gain of the system is the subject.Also, the article looks into the future of A/C EMC design, put forward the mechanism-electrical system consider and design requirement, to promote the high precise digital measurement system technology development and get engineering experience on EMC design, so as to satisfy the integration of mechanical-electrical system.