Design And Development Of The Main Reducer Fault Diagnosis System Based On Vibration Signal Of Helicopter

The transmission system,one of the three major dynamic components of helicopter,whose structure characteristics decides its no redundancy, and its fault will threat the flight safe of the helicopter directly.While the main reducer is the key of the transmission system, it has many internal gears which are heavy loaded. Especially in the course of its operation, interaction betweenclearance, external force, friction or other factors and its dynamic behavior will make it deviate from the ideal operation condition, cause malfunction easily, and even lead to catastrophe.Therefore, establishing the fault diagnosis system for the main reducer is a very important subject.The goal of this paper is the design of the fault diagnosis system for the main reducer ofhelicopter, the system is mainly based on the analysis of vibration signal. The main research contents include:1) Analyze the requirement analysis and structural characteristics of main reducer.2) According to the existing fault statistics,study the common failure mode of the main reducer,and analysis of the vibration mechanism of the failure mode.3) Study and analyze common fault monitoring method of helicopter components, and choose the fault monitoring method for the main reducer diagnosis in this paper.4) Introduce the design of fault diagnosis system frame, including the design of sensor andairborne processor.5) Meanwhile, it introduce common used signal processing methods:6) Based on the analysis and research above,study the feature selection metric and parameter estimation method.Analyze the collected flight test dataand finish the feature extraction.7) After analyzing the characteristics,choose the process of the the threshold’s setting up.Based on data driven approach, establish the initial warning and alarm threshold of the airborne system, complete the design of the fault diagnosis of the main reducer, and validate with the flight data.