Fault Diagnosis On Fuel Control System Of A Certain Aero-engine

Fuel control system is quite an important component of a whole aero-engine control system. As the accuracy and stability of an aero-engine control system is increased these years, the performance of fuel-control system is quite important to help achieve that point. Furthermore, many common problems are caused by fuel-control system. So research on fault diagnosis of fuel control system has import engineering significance.The working mechanism of aero-engine is complicated, so we can not figure out failure without a deep understanding of it. For this special situation mentioned above, knowledge model based on SDG(signed Directed Graph) can express complex relationship. SDG has a huge potential in covering large-scale information and can solve well for the problem. Comparing with other method, SDG is simple and audio-visual, which make it quite easy for practical use. Based on the engineering experiences, we establish a SDG expert system model for fuel control system. Then we work out its realization and verify the effectiveness of it.As a core component of fuel-control system, the working performance of electro-hydraulic servo valve directly affects the stability and accuracy of the whole servo system. Research on fault diagnosis of electro-hydraulic servo valve has important engineering significance. Besides the fault diagnosis of the whole fuel control system, this paper also focuses on the fault analysis of electro-hydraulic servo valve. For a certain twin flapper-nozzle electro-hydraulic servo valve, analysis its work mechanism, build its hydraulic model and alter some parameters of it to simulate fault. On this basis, employ SVM,PCA-SVM and WPEE-SVM to train and classify the fault data. After comparison, verify the effectiveness of algorithm and choose PCA-SVM as the best method.At last, we introduce the simulation platform of aero-engine. We also explain the structure and function of the platform in brief.