The Research Of The Test Bed Gearbox Vibration Testing System Based On Cyclic Spectrum

A complete set of multi-channel vibration measurement virtual instrument system isdeveloped on background of the researching of some aircraft high load component test bench.The system works closely with the practical needs，on the basis of LabVIEW virtualinstrument software platform, vibration test theory and the theory of cyclic spectrum. Thefollowing test result of the debugging and commissioning process proved the effective of thesystem. At the same time, analytical and researchful comparisons were made with thetraditional analysis method such as Hilbert, and FFT envelope spectrum, which show a bettervibration signal demodulation and noise reduction performance of the cyclic spectrum theoryin this test bench. The main research contents of this paper are summarized as follows:(1) Theoretical deduction and analysis of the cyclic spectrum which used in this systemwas made. Through the simulation of a series of common of mechanical fault signal, rigorousanalytical studying of the demodulating performance of the cyclic spectrum has been done,which deepen the cognition of the cyclic spectrum theory and laid a good theoretical basis forthe next engineering application.(2) The mechanical system structure of test bed and potential failure points wereanalyzed and researched. Combined with the actual project requirement, the reasonablematching of the hardware and the scientific arrangement of measuring point of the vibrationtesting system has been made.(3) In the LabVIEW development environment, the realization of fast storage andaccurate query of multi-channel, multi-type vibration data is studied. Research anddevelopment of the module to complete the bulk data storage, query, print, derived functionbased on TDMS (technical data management streaming) data model has been completed.(4) Humanization design of the system interface is on the basis of research results fromcomputer science, cognitive psychology, ergonomics and etc. Good results are achieved afterthe debugging test of control, hydraulic, mechanical system and the developed vibration testing system.(5) Analytical and researchful comparisons used several groups collected vibrationsignals of test bench were made with analysis method such as Hilbert, and FFT envelopespectrum. The results show that, the cyclic spectrum theory has the practicability andsuperiority in fault diagnosis in this test system.(6) The cyclic spectrum analysis is combined with the test drive structure characteristicsto deduce the potential failures of the test bed. And guidelines for improvement have beenproposed.To sum up, the monitoring system developed on the background of a certain type of testbench has both of the good performance and the control interface, make it a reference to thesimilar engineering practice. At the same time, the cyclic spectrum theory applicated in thefailure analysis of this test bed has certain reference value to the application of on similarproblems.