Study On Vehicle Alternator Noise Characteristics And Noise Source Identification

Reducing generator noise is an urgent problem to enhance automobile product quality. Toanalyze automobile generator noise characteristics and identify the noise source is thefoundation and key to reduce noise.This article relies on Motor Co.Ltd. Jinzhou Halla project "192F automobile generatorvibration and noise research"(NO:2012050), a study for meeting the actual needs ofenterprises. First, automobile generator noise characteristics and influencing factors areanalyzed. Mechanical noise, electromagnetic noise and air noise generation mechanismanalysis is made by studying the structure of automobile generators. Factors that influencenoise are analyzed by studying the automobile generator’s continuity, frequency and order;secondly, generator noise source identification is studied. The main process of researchingincludes noise data acquisition and pre-processing and noise source graphic analyzing whichconsists of analysis under different orders, analysis in time domain and analysis in frequencydomain. The Elman neural network is chosen to identify generator noise source, and the noisesource identification program is made by completing network program design, validating theresults, optimizing the network and selecting algorithms etc. The new interactive visualizationsoftware of generator noise source identification analysis is developed by using guideplatform of Matlab; Lastly, Use the developed software to analyze the192F automobilegenerator noise and identify noise source. The analyzing process mainly includes the overallnoise analysis, main order analysis, spectral analysis of a generator and noise sourceidentification.Analysis and recognition results are:192F harmonic resonance of automobile generatorelectromagnetic vibration and wind deflector’s coordination with vanes are the two maincauses of the noise, which means that the purpose of identifying noise source is achieved.Generator noise analysis and noise source identification software developing simplifies thenoise source identification process, save judgment time and improve efficiency. These studiesprovide references for the automotive generator noise research and Generator productionenterprises who seek measures to reduce noise.