聲中頻檢波器 的英文怎麼說
中文拼音 [shēngzhōngbīnjiǎnbōqì]
聲中頻檢波器
英文
sound intermediate-frequency detector- 頻 : Ⅰ形容詞(次數多) frequent Ⅱ副詞(屢次) frequently; repeatedly Ⅲ名詞1 [物理學] (物體每秒鐘振動...
- 檢 : Ⅰ動詞1 (查) check up; inspect; examine 2 (約束; 檢點) restrain oneself; be careful in one s c...
- 波 : Ⅰ名詞1 (波浪) wave 2 [物理學] (振動傳播的過程) wave 3 (意外變化) an unexpected turn of even...
- 器 : 名詞1. (器具) implement; utensil; ware 2. (器官) organ 3. (度量; 才能) capacity; talent 4. (姓氏) a surname
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The master dissertation introduces passive correlative orientation system and base theory in signal dispose briefly in the first place. the system takes tv sound fm signal from tv satation signal. the power rate of tv station signal to sound signal is ten to one. in the case of submerged by mussy weave and machine ' s hot noise, dispersed target signal is feeble
系統採用電臺的電視伴音調頻信號,其中電臺信號與伴音信號功率之比基本為10 : 1 ,並且目標散射信號較弱,一般情況下淹沒在雜波和機器熱噪聲之下,採用常規的脈沖檢測方法很難對遠距離的目標進行檢測,而以電臺直達信號作為參考與目標回波信號進行相關檢測;系統中信號的相關處理會產生旁瓣,而強目標的旁瓣會影響附近的弱目標檢測。A digital automatic ultrasonic inspection system designation is introduced. this system was developed with pc computer and embedded dsp, combining computer software and hardware, ultrasonic nondestructive testing, digital signal processing, embedded rtos and visual instruments technology. it meet the requirements of automatic inspection such as high repetitively frequency and real time alertation
該方案以pc機和dsp系統為核心構成主從機系統框架,以基於虛擬儀器思想的pc機應用程序和基於dsp的嵌入式實時操作系統構成雙重軟體結構,把傳統的超聲波無損檢測技術和先進的虛擬儀器技術、數字信號處理技術、嵌入式實時操作系統、計算機介面通信技術相結合,從而滿足了自動化探傷中1k / s的重復頻率和實時報警的要求。Section ii describes the design approach and implementation of speech module on mcf5249 coldfire core. the speech codec optimizes g. 729a codes and added voice activity detection of g. 729b to save bandwidth ; the implementation of acoustic echo cancellation uses nlms algorithm and it can reduce echo though designing adaptive fir filter and speech detector ; the dtmf and cpt generate signal using two second order digital sinusoidal oscillators and detect signal by picking up the frequency information. but only get the frequency information is not enough in cpt detector, this thesis introduces a method
其中對語音編解碼器的設計採用優化g . 729a代碼達到設計要求,並在此基礎上加入g . 729b的靜音檢測模塊,以進一步降低網路傳輸帶寬;對回聲消除器的設計採用nlms演算法,通過設計自適應fir濾波器和語音檢測器達到回聲消除目的;對雙音多頻設計,信號發生端採用構造靜態參數表並通過二階正弦振蕩器產生信號,信號檢測端提取頻率信息以檢測信號;對呼叫進程音設計,除了類似雙音多頻的信號發生及頻率檢測設計外,還需要檢測信號持續時間,作者設計了一種基於匹配狀態表的方法以檢測信號持續時間。Conventional detector ( single - user matched filter ) distinguishes each user by the crosscorrelation of their spread - spectrum codes. in practice, however, its performance is much deteriorated due to the existence of noise in channel and strong multi - access interference, i. e. near for effect. a new method using independent component analysis is proposed in this paper. the - received energy of signals is controlled effectively, thus the near - far effect is overcome as much as possible ; moreover, the effect that noise imposed on the detector is mostly reduced. simulations verify the effectiveness of this method
傳統檢測器(單用戶匹配濾波)利用擴頻碼之間的互相關特性來區分各用戶信號.而在實際應用中,通道噪聲和近距離用戶對遠距離用戶的強多址干擾即遠近效應,使得接收機的性能受到很大影響.本文將獨立分量分析法引入傳統接收機,有效控制接收信號的能量,從而極大地提高了接收機的抗遠近性能,同時噪聲的影響被盡可能消除.模擬結果表明了該方法的有效性和可行性The main results of this paper are as fellows f 1 ) illtroducing the ultrasonic technology to the rigid measurement, successful1y exploits the practical small intellectualized ultrasonic device of measuring rigidity by applying mechanical technology, electronic technology and computer science 2 ) reading clearcf displaying more various, applying more information, being easiest to accept by user because of adopting liquid crystal display ( lcd ) 3 ) theorizing the mathematical model between the signal of frequency and the rigid value on the device, possessing very importan practical significance 4 ) optimizing the every parts of the device, achieving the goals of lower wastage of energy, smaller, lighter and inexpensive 5 ) taking the measure to reduce the wastage of energy and adopting reasonable management in power supply for the device, making the device skimp more energy, prolonging the life - span of battery 6 ) utilizing the interface of rs - 232, discussing the communication between the ultrasonic device of measuring rigidity and computef, and also forecasting the foreground of advanced exploitation by user
本文工作的主要成果是: 1 )將超聲波技術引入零件表面硬度的檢測當中。應用機、電、計算機技術,研製成功較為實用的小型智能超聲波硬度檢測儀2 )採用lcd ( liquidcrystaldisplay )液晶顯示,使讀數更清晰、顯示多樣化、信息量多、易於為用戶接受3 )在理論上建立了該系統的頻率信號與硬度值的數學模型,具有非常重要的實踐意義4 )對各元器件進行優選,達到低能耗、體積小、重量輕、價格便宜等目的5 )採取措施降低整個系統的能耗並對系統的供電進行了合理的管理,使其進一步達到低能耗,延長了電池的使用壽命。 6 )利用rs - 232標準介面,討論了該超聲波智能硬度測量儀與系統機進行通訊以及用戶進行二次開發的前景Presents the simple but highly reliable on - line detection of ultrasonic transducer clamping capacitance based on the impedance circuit model constructed through the impedance characteristics of the ultrasonic transducer under triple harmonics, and concludes from experimental results that this method can be used to effectively detect the variation of clamping capacitance while the transducer is operating, and the matching inductance can be dynamically regulated according to the results of detection, and dynamic matching can therefore be achieved in the real sense at the end of the transducer to improve the overall performance of the whole system
為了解決大功率超聲應用的換能器電端匹配問題,分析了超聲波換能器在諧振頻率三次諧波下的阻抗特性,給出了超聲換能器三次諧波下的阻抗電路模型.並根據阻抗電路模型建立了對超聲換能器的夾持電容實現在線檢測簡單、可靠性高的方法,實驗證明該方法有效的.該方法可以在換能器工作過程中隨時檢測夾持電容的變化,根據檢測結果對匹配電感進行動態調整,實現真正意義上的換能器電端的動態匹配,從而大大改善匹配質量,提高系統的工作性能分享友人