本文選題：參量陣 + 聲吶��； 參考：《電子科技大學》2016年碩士論文

【摘要】：聲吶設備的用途十分廣泛,其在軍事和民事上的應用誘發(fā)了并大力推動了聲吶技術的研究與發(fā)展。聲吶技術的一個研究熱點便是增加它的作用距離,但目前,各方面的原因都在一定程度上限制了其作用距離的增加。利用介質中的非線性作用,參量陣技術可以生成二次聲波,這個聲波的頻率比較低,適合于遠距離傳播,該二次聲波還具有很強的指向性。而且,由于原波的頻率較高,所以發(fā)射陣的尺寸并不需要太大。參量陣的這些優(yōu)點恰好可以應用在主動聲吶之中,增大聲吶的作用距離,并且其高指向性也能被很好地應用于聲吶中,增加聲吶的方位分辨力。本文研究聲吶發(fā)射波形與參量陣調制技術的結合,分析DSB調制算法和SSB調制算法對CW信號和LFM信號的作用機制,利用Berktay遠場解,分析CW信號和LFM信號在各個調制算法作用下所生成的二次聲波的形式。通過對二次聲波頻域特性和時域特性的研究,得到幾種可行的發(fā)射波形和參量陣調制技術的組合。結果表明,DSB法和全載波SSB法能很好地應用于參量陣聲吶中,抑制載波SSB法不適用于參量陣聲吶。全載波調制算法將產生頻率為輸入信號兩倍的諧波,調制系數的降低有利于減少諧波失真,但同時也會降低有效信號的幅度。抑制載波DSB法產生二次聲波的頻率比較單一,其頻率為輸入信號的兩倍,可以用做主動聲吶的探測信號。通過對發(fā)射波束指向性控制的研究,提出了一種發(fā)射基陣陣列設計方法,設計了參量陣聲吶的發(fā)射陣列,該平面陣采用5*15的矩形組陣形式,其水平方向上有5列,指向性開角為3.8度,垂直方向上有15行,指向性開角為13.1度。研究了參量陣聲吶的相控偏轉方法,利用時延波束合成技術,實現了本系統(tǒng)發(fā)射信號的相控發(fā)射。開發(fā)了一個基于FPGA的硬件處理平臺,在該平臺上完成了參量陣聲吶的信號處理算法,包括:發(fā)射波形設計、調制算法、時延波束合成技術。在消聲水池環(huán)境中,搭建了實驗平臺,通過對接收信號的波形和極大值方位的分析,驗證了參量陣聲吶的可行性,驗證了本系統(tǒng)算法的正確性。
[Abstract]:Sonar equipment is widely used. Its application in military and civil affairs induces and promotes the research and development of sonar technology. One of the research hotspots of sonar technology is to increase its range of action, but at present, all kinds of reasons restrict the increase of its range to some extent. The parametric array technique can generate secondary sound wave by using nonlinear action in medium. The frequency of this sound wave is relatively low, which is suitable for long distance propagation, and it also has strong directivity. Moreover, due to the high frequency of the primary wave, the size of the emitter array does not need to be too large. These advantages of parametric array can be used in active sonar to increase the range of sonar, and its high directivity can also be applied to sonar to increase the azimuth resolution of sonar. In this paper, the combination of sonar emission waveform and parametric array modulation technology is studied. The mechanism of DSB modulation algorithm and SSB modulation algorithm on CW signal and LFM signal is analyzed, and the far field solution of Berktay is used. The form of quadratic acoustic wave generated by CW signal and LFM signal under the action of each modulation algorithm is analyzed. Based on the study of frequency domain and time domain characteristics of quadratic acoustic wave, several feasible waveforms and parametric array modulation techniques are obtained. The results show that the DSB method and the full carrier SSB method can be applied to parametric sonar very well, but the suppression carrier SSB method is not suitable for parametric sonar. The full-carrier modulation algorithm will produce harmonics twice the frequency of the input signal. The decrease of modulation coefficient will help to reduce the harmonic distortion, but also reduce the amplitude of the effective signal. The frequency of secondary acoustic wave produced by suppressing carrier DSB method is single, and its frequency is twice that of input signal, so it can be used as the detection signal of active sonar. Based on the research of beam directivity control, a design method of emission matrix array is proposed, and the emission array of parametric sonar is designed. The planar array is a rectangular array with 5 columns in horizontal direction. The directivity angle is 3.8 degrees, the vertical direction is 15 rows, and the directivity angle is 13.1 degrees. The phase-controlled deflection method of parametric sonar is studied. The phased emission of the system is realized by using the time-delay beam synthesis technique. A hardware processing platform based on FPGA is developed, on which the signal processing algorithm of parametric sonar is completed, including: waveform design, modulation algorithm and time-delay beam synthesis technology. The experimental platform is built in the environment of the silencing tank. The feasibility of the parametric sonar is verified by analyzing the waveform and maximum azimuth of the received signal, and the correctness of the system algorithm is verified.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TN830

【參考文獻】

相關期刊論文 前6條

1 萬們;牟澤霖;;Chirp型淺地層剖面儀和參量陣淺地層剖面儀的對比分析[J];地質裝備;2015年04期

2 呂國濤;溫明明;吳衡;李永航;;PARASOUND P70淺剖在大洋科考中的應用[J];內江科技;2013年02期

3 李頌文;;參量陣及其在水聲工程中的應用進展[J];聲學技術;2011年01期

4 陳奇;徐行;石要紅;潘毅;;國內外海底靜力觸探的技術研究與進展[J];南海地質研究;2009年00期

5 紀鳴;吳亞鋒;韓斌;;聲音定向傳輸中的失真分析[J];聲學技術;2005年04期

6 張兆富;SES-96參量陣測深/淺地層剖面儀的特點及其應用[J];中國港灣建設;2001年03期

相關會議論文 前1條

1 華樂蓀;;參量陣和相關技術在海底剖面儀中的應用[A];水下淺地層剖面儀專輯[C];1982年

相關博士學位論文 前1條

1 陳敏;聲頻定向系統(tǒng)理論與關鍵技術研究[D];電子科技大學;2008年

，

本文編號：1787222