本文選題：聲場　切入點：振動檢測　出處：《華東交通大學》2017年碩士論文　論文類型：學位論文

【摘要】：非接觸式振動檢測方法是一類重要的機械振動檢測方法,其在振動檢測領域中起到無可替代的重要的作用。在非接觸式振動檢測方法中,傳感器與被測物體相互隔離,能夠在不干擾被測對象的情況下實現(xiàn)振動檢測,尤其可用于對表面粗糙、細微、質輕及柔性結構的振動檢測。在常見的非接觸式振動檢測方法中,基于超聲波的機械振動檢測方法即超聲波測振法有其自身的獨特優(yōu)勢,具有測量精度高、測量電路簡單、成本低、通用性強等特點,能夠運用于煙霧、不透明氣體、強腐蝕、強光等環(huán)境中進行振動檢測,對超聲波反射性能好、表面粗糙度小于超聲波波長的表面都能對其進行振動檢測。因此,有必要對超聲波測振技術進行深入研究。本文首先對超聲波振動檢測技術及超聲波測振信號解調算法進行了綜述;基于超聲波的多普勒效應及聲參量效應詳細介紹了超聲波測振原理,并建立了受振動調制的超聲波反射回波數學模型;根據超聲波反射回波數學模型以及超聲波振動檢測原理得出了影響超聲振動檢測精度的三個主要因素—超聲波聲速、入射超聲波頻率、傳感器探頭安裝位置。對超聲波聲速的影響因素以及傳感器的安裝位置進行了深入研究,提出了修正超聲聲速的方法,確定了傳感器的合理安裝位置。參考前人的研究成果,綜合考慮不同頻率超聲波在空氣中的傳播特性,選擇采用40KHz的超聲波信號進行振動檢測研究;以中心頻率為40 KHz超聲波傳感器直徑大小為研究對象,對不同尺寸的傳感器進行聲場及指向性研究,基于該研究結果,結合成本因素及傳感器獲取的難易程度,對超聲波傳感器進行選型。采用Hilbert變換解調算法及能量算子解調算法分別對超聲波測振仿真信號進行解調,提取出被測物體的振動速度信號。針對選用Hilbert變換解調算法獲取的振動速度曲線有端點效應,能量算子解調算法因誤差項的存在限制了所能測量的振動頻率范圍從而影響解調精度問題,提出了一種改進的歸一化復域能量算子解調算法并用該算法對超聲波測振信號進行處理,將處理結果與Hilbert變換解調算法及能量算子解調算法的解調結果進行對比分析,結果表明該方法能獲得更好的解調效果。最后,基于上述研究進行超聲波振動檢測系統(tǒng)設計,搭建超聲振動檢測實驗臺,開展超聲波振動檢測實驗,將超聲波測振信號解調得到的振動速度與加速度傳感器輸出信號積分求得的振動速度信號進行對比分析,實驗結果證明了上述理論研究的正確性和可行性。
[Abstract]:Non-contact vibration detection method is an important kind of mechanical vibration detection method, which plays an irreplaceable role in the field of vibration detection. It can be used to detect vibration without disturbing the object, especially for rough, fine, light and flexible structure. In the common non-contact vibration detection method, Ultrasonic vibration detection method based on ultrasonic has its own unique advantages, such as high measuring precision, simple measuring circuit, low cost and strong generality. It can be used in smoke, opaque gas, strong corrosion, etc. Vibration detection in strong light and other environments can detect the vibration of ultrasonic wave when the surface roughness is less than ultrasonic wave length. It is necessary to study the ultrasonic vibration measurement technology deeply. Firstly, the ultrasonic vibration detection technology and the demodulation algorithm of ultrasonic vibration signal are summarized in this paper. Based on the Doppler effect and parametric effect of ultrasonic wave, the principle of ultrasonic vibration measurement is introduced in detail, and the mathematical model of ultrasonic reflection echo modulated by vibration is established. According to the mathematical model of ultrasonic reflection echo and the principle of ultrasonic vibration detection, three main factors affecting the accuracy of ultrasonic vibration detection are obtained: ultrasonic velocity, ultrasonic frequency, and ultrasonic frequency. The influence factors of ultrasonic sound velocity and the installation position of sensor are studied in depth, and the method of correcting ultrasonic sound velocity is put forward, and the reasonable installation position of sensor is determined. Considering the propagation characteristics of ultrasonic wave with different frequencies in the air, the ultrasonic signal of 40kHz is selected for vibration detection, and the diameter of the ultrasonic sensor with central frequency of 40kHz is taken as the research object. The acoustic field and directivity of sensors with different sizes are studied. Based on the results of the research, combined with the cost factors and the degree of difficulty in obtaining the sensors, Hilbert transform demodulation algorithm and energy operator demodulation algorithm are used to demodulate the simulation signal of ultrasonic vibration measurement. The vibration velocity signal of the measured object is extracted. The vibration velocity curve obtained by using the Hilbert transform demodulation algorithm has an endpoint effect. The energy operator demodulation algorithm limits the range of vibration frequency which can be measured because of the existence of error term, which affects the demodulation accuracy. An improved normalized complex energy operator demodulation algorithm is proposed to process ultrasonic vibration signal. The results are compared with those of Hilbert transform demodulation algorithm and energy operator demodulation algorithm. The results show that this method can obtain better demodulation effect. Finally, the ultrasonic vibration detection system is designed based on the above research, and the ultrasonic vibration detection experiment bench is built, and the ultrasonic vibration detection experiment is carried out. The vibration velocity obtained by demodulating the ultrasonic vibration signal is compared with the vibration velocity signal obtained by the integral of the output signal of the acceleration sensor. The experimental results prove the correctness and feasibility of the above theoretical research.
【學位授予單位】：華東交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TH113.1;TB559

【參考文獻】

相關期刊論文 前10條

1 曹青松;陳剛;周繼惠;;超聲波測振信號的Hilbert變換解調方法研究[J];測試技術學報;2016年05期

2 曹青松;陳剛;畢彬杰;周繼惠;;超聲波測振信號的能量算子解調方法[J];噪聲與振動控制;2016年05期

3 周繼惠;陳剛;曹青松;猶X;;基于多普勒效應的超聲波測振系統(tǒng)設計[J];儀表技術與傳感器;2015年07期

4 辛松;芮筱亭;王國平;張建書;楊富鋒;;艦載多管火箭振動控制方法研究[J];南京理工大學學報;2015年01期

5 蔡光昭;洪遠泉;周永明;;基于STM32的超聲波測速測距系統(tǒng)設計[J];現(xiàn)代電子技術;2014年24期

6 王麗莉;;海拔高度與大氣壓關系的回歸計算[J];價值工程;2014年23期

7 孟宗;李姍姍;季艷;;基于對稱差分能量算子解調的局部均值分解端點效應抑制方法[J];機械工程學報;2014年13期

8 曾鳴;楊宇;鄭近德;程軍圣;;歸一化復域能量算子解調及其在轉子碰摩故障診斷中的應用[J];機械工程學報;2014年05期

9 劉雪林;史湘?zhèn)?黃興洲;薛德寬;陳文娟;;超聲波測距聲場仿真研究[J];現(xiàn)代電子技術;2014年05期

10 任達千;楊世錫;吳昭同;嚴拱標;孟慶波;;信號瞬時頻率直接計算法與Hilbert變換及Teager能量法比較[J];機械工程學報;2013年09期

相關博士學位論文 前1條

1 潘仲明;大量程超聲波測距系統(tǒng)研究[D];國防科學技術大學;2006年

相關碩士學位論文 前6條

1 謝齊;軌道不平順作用下高速列車運行舒適性分析[D];大連理工大學;2014年

2 邢傳奇;基于光纖干涉儀的非接觸振動測試技術研究[D];大連理工大學;2013年

3 朱宇川;飛機發(fā)動機振動檢測設備標定裝置的研發(fā)[D];武漢理工大學;2013年

4 孟凡凱;水下超聲波檢測聲場數值模擬與實驗分析[D];哈爾濱工業(yè)大學;2012年

5 蒙海英;基于MATLAB的超聲波聲場模擬及可視化研究[D];大連理工大學;2008年

6 陳印梅;基于LabVIEW的大型旋轉機械趨勢分析與狀態(tài)監(jiān)測系統(tǒng)的研究與應用[D];武漢科技大學;2006年

，

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