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  本文關(guān)鍵詞：基于聲發(fā)射的機(jī)械斷裂定位研究　出處：《中國礦業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 鑄件 聲發(fā)射源定位 特征參數(shù) 濾波器 離群點(diǎn)分析

【摘要】：隨著聲發(fā)射技術(shù)的發(fā)展和相關(guān)學(xué)者對金屬材料聲發(fā)射現(xiàn)象的研究,以及信號處理技術(shù)的提高,使得聲發(fā)射在機(jī)械故障檢測領(lǐng)域有了更廣闊的應(yīng)用。目前的聲發(fā)射檢測設(shè)備多以PC機(jī)為平臺,通過軟件提取聲發(fā)射信號的特征參數(shù),對于密集型聲源經(jīng)常漏失信號,且針對機(jī)械斷裂故障的聲發(fā)射源定位研究不足�；诖�,本文設(shè)計(jì)了基于嵌入式平臺的聲發(fā)射檢測儀,研究分析了特征參數(shù)提取和源定位。本文首先講述了機(jī)械鑄件釋放聲發(fā)射波的機(jī)理,介紹了聲發(fā)射信號的時(shí)域特征、頻域特征和常用特征參數(shù)的含義及計(jì)算公式;介紹了最常用的基于時(shí)差的線性定位、平面定位和三維定位原理;根據(jù)聲發(fā)射檢測系統(tǒng)各環(huán)節(jié)容易引入噪聲的特點(diǎn),設(shè)計(jì)了針對于機(jī)械鑄件的模擬帶通濾波器;設(shè)計(jì)了聲發(fā)射信號識別狀態(tài)機(jī),利用FPGA的硬件平臺優(yōu)勢,高效完成特征參數(shù)的提取;針對聲發(fā)射源時(shí)差定位提出基于離群點(diǎn)分析的Chan定位算法,該算法原理簡單、計(jì)算量小且定位精度高;最后通過方案論證完成對元器件的選型和選定基于FPGA和STM32的硬件平臺,并著重講解了特征參數(shù)提取的Verilog HDL代碼和定位算法的C代碼實(shí)現(xiàn)思路。為驗(yàn)證模擬濾波器的去噪效果、特征參數(shù)提取效率和聲發(fā)射源定位精度,通過Modelsim時(shí)序仿真和與實(shí)際儀器數(shù)據(jù)比較,證明系統(tǒng)可以完成4通道數(shù)據(jù)采集、實(shí)時(shí)特征參數(shù)提取并完成聲發(fā)射源定位。本文研究成果對后續(xù)針對機(jī)械故障的聲發(fā)射檢測和專用儀器設(shè)備研制具有實(shí)踐意義。
[Abstract]:With the development of acoustic emission technology and related research on the emission of metal material sound, and signal processing technology, the acoustic emission in the field of mechanical fault detection has a wider application. At present, the acoustic emission testing equipment based on PC platform, through the software to extract characteristic parameters of acoustic emission signals, for intensive sound source often missed signal, and according to the mechanical fault acoustic emission source location research. Based on this, this paper designs an embedded platform of acoustic emission tester based on research and analysis of the extraction and localization parameters. This paper describes the mechanism of mechanical casting release of acoustic emission wave, the time domain features the acoustic emission signal, the meaning and calculation formula of the frequency characteristics and the common characteristic parameters; introduces the linear positioning time based on the most commonly used, plane positioning and three-dimensional positioning according to the principle; The characteristics of acoustic emission of each link detection system to introduce noise, designed for simulation of mechanical casting band-pass filter design; acoustic emission signal recognition of state machine, using the advantages of FPGA hardware platform, extraction and efficient completion of characteristic parameters; the acoustic emission source location is proposed Chan localization algorithm based on the outlier analysis. The algorithm is simple in principle, less computation and high accuracy; finally through the demonstration program completed selection of components and selected based on FPGA and STM32 hardware platform, and explains the Verilog HDL code and localization algorithm feature extraction C code method. Filter denoising effect for simulation, feature extraction efficiency acoustic emission source location accuracy by comparing Modelsim simulation and actual data and instrument, it is proved that the system can complete 4 channel data acquisition, real-time characteristic parameters The localization of acoustic emission sources is extracted and completed. The results of this paper have practical significance for the follow-up of acoustic emission detection for mechanical faults and the development of special instrument and equipment.

【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG115

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本文編號：1380192