混疊誤差 的英文怎麼說
中文拼音 [húndiěwùchā]
混疊誤差
英文
aliasing error-
The paper designs a more lpf and a numberical filter to eliminate the error, and a frequency tracing tache because system frequency fluctuates ceaselessly. this guarantes synchronization sampling
為了消除頻率混疊帶來的誤差，專門設計具有較好性能的低通濾波器和數字濾波器；由於系統頻率波動性，設計有硬體電路組成的頻率跟蹤環節，最終實現采樣周期和信號周期同步。From theoretical analysis, we know the existing demodulation methods have limitations as following : one is that the subtraction of the two signals frequencies will display as the result of demodulation when we demodulate two time - domain adding signals without modulating information ( fault information ) ; the other one is that aliasing phenomenon will occur as a result of getting absolute value, detection or square in the process of generalized demodulation analysis, such phenomenon will result in some superfluous frequency composition on the frequency spectrum, which will puzzle the detec tion of mechanical vibration. if the sampling frequency is selected from a suitable range, the aliasing phenomenon will be avoided ; the last one is that aliasing frequencies will be produced in zoom demodulation analysis because this algorithm cannot employ digital low - pass filtering to avert the folding frequencies of higher harmonics in the process of zoom sub - sampling
現有的解調分析方法存在以下三種局限性：將不包括調制信息（故障信息）的兩時域相加信號，也以其頻率之差作為解調信號而解出；廣義檢波濾波解調分析中，由於取絕對值、檢波或平方過程可能產生混頻效應，在解調譜中表現為無法分析的頻率成分，並由此推導出避免這種混頻現象的采樣頻率的選取范圍，從根本上避免此類誤診斷的產生；幾種細化解調分析新演算法中，因為無法在細化分析的選抽時進行數字低通濾波，有可能會出現調制頻率的高次諧波成分發生頻率混疊而反折到低頻部分的現象。In the first part, the research progress of cloud motion wind was introduced and the significance of the 1 - d fourier analysis technique was given. in the second part, based on fluctuation theory and fourier analysis, the one dimension fourier analysis technique on cloud motion winds is deduced and demonstrated theoretically. by simulating mathematically on frequency and on space, we not only uncovered two questions in practice, first is phrase folding, second is frequency spectrum overlapping, but also gave methods and suggestions to solve them or avoid them
本文由六章組成，第一章介紹雲導風技術的研究進展和傅立葉導風技術的研究意義；第二章以波動理論和傅立葉變換為基礎，對傅立葉相位導風技術進行理論推證和誤差分析，通過模擬分析了空間域和頻率域的導風特點，揭示了在導風過程中出現的相位重疊和頻譜混疊兩種現象；第三章通過計算在空間域速度線性變化情況下頻率域振幅權重平均速度（
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