Vibration/Temperature Data Processing And Program Design Of Environmental Spectrum For Aircraft Airborne Equipment

The vibration/temperature data processing of environmental spectrum is an important part of environmental reliability test for aircraft airborne equipment. The aircraft airborne equipment constantly works in the various environments. The environment of vibration and temperature can seriously diminish the service life of the aircraft structure. It can affect security and reliability of aircraft airborne equipment. It can lead to many aircraft airborne equipment to be destroyed and many serious results have happened. To sum up, the authenticity of vibration/temperature data processing has great significance for guaranteeing the security and reliability of aircraft airborne equipment.This paper takes JL8 aircraft as an example. At first we must carry on the installation of the electric apparatus and then choose 111 effective flights as the processing data source of the environmental spectrum for aircraft airborne equipment.How to get rid of erroneous data is researched and the distinguishing method of general erroneous data and rejective criterion are pointed out. At last this paper indicates the rectification method for those measurement data before analysis, so we can remove some kind of abnormal data.The wavelet transform as a new-type subject which comes from Fourier transform has been used widely in a lot of subjects and fields after more than ten years of development. This paper makes an elementary research about extraction method for period signal from random signal by wavelet transform. This paper mainly includes two aspects of the environmental spectrum data processing for aircraft airborne equipment. We should carry on the pretreatment (data pre-processing) at first and then carry on the formal data processing (deal with the environmental parameter of airborne equipment). We carry on data pre-processing after typical segment dividing and data checking.Welch method and Cooley-Tukey method are adopted for the formal data processing at first. It calculates the density of power spectrum of vibration for the aircraft at different flight profiles, different flight segments of each equipment cabin. Then the application program we coded provides the chart of power spectrum density for each cabin. At last it envelops vibration data, so it can provide vibration stress of each aircraft equipment cabin during the course of differently flying task.The Object Oriented Program language, i.e. Visual C++ .NET is used in the programming of data processing application. Combining the programming step of the software engineering, this paper has finished the systematic module design of the environmental spectrum data processing. On the base of original SmartDSP system, the aim of this design is the automation of data processing. This system mainly includes the parameter configuration, coordinate transformation, window function, confidence level and quantile switching, etc.The achievement has been successfully applied to the vibration/temperature data processing of environmental spectrum for JL8 and Y7G aircraft airborne equipment. It has achieved great economic benefits and social effect. The achievement will become important driving force for the development of vibration/temperature data processing of environmental spectrum for aircraft airborne equipment. It also has laid a foundation for carrying out vibration/temperature data processing of environmental spectrum for aircraft airborne equipment in the future.