Research on Fault Diagnosis Method of Civil Aviation Engine Variable Bleed Valve System Based on Artificial Immune Algorithm

Variable Bleed Valve (VBV) system is an important component of civil aviation engine which can be used to adjust the opening degree of bleed valve. By adjusting the opening degree of bleed valve, a part of outlet air from low-pressure compressor can flow into the fan so as to improve the working stability of low-pressure compressor. VBV system was chosen as the research object in this paper, which internal structure and composition were analyzed and its model was established from part to the whole at first. Then, the negative selection algorithm of variable radius detectors was researched to achieve VBV system faults diagnosis by selecting characteristic parameters and setting up multi-type fault diagnosis process. At last, electrohydraulic servo valve fault, VBV system controller fault and linear variable differential transformer fault were intentionally set up to verify the effectiveness of fault diagnosis method. Through the process of detector generation and fault recognition, the faults in VBV system can be diagnosed effectively.