【摘要】：光子相關(guān)光譜技術(shù)作為測(cè)量納米顆粒粒徑及其分布的主要方法,在納米顆粒測(cè)量領(lǐng)域得到了廣泛應(yīng)用。光子相關(guān)器是光子相關(guān)光譜測(cè)量系統(tǒng)的核心裝置,通過對(duì)光子脈沖計(jì)數(shù),并進(jìn)行實(shí)時(shí)自相關(guān)運(yùn)算得到散射光強(qiáng)的時(shí)間自相關(guān)函數(shù)。目前國(guó)內(nèi)使用的光子相關(guān)器多為進(jìn)口產(chǎn)品,因此,設(shè)計(jì)開發(fā)具有自主知識(shí)產(chǎn)權(quán)的大動(dòng)態(tài)范圍高速光子相關(guān)器具有重要的經(jīng)濟(jì)和社會(huì)效益。 本文圍繞擴(kuò)大相關(guān)器動(dòng)態(tài)范圍、提高相關(guān)器運(yùn)算速度及相關(guān)函數(shù)的歸一化精度,進(jìn)行了以下研究工作： (1)基于光子相關(guān)光譜理論,研究了線性光子相關(guān)器、比例光子相關(guān)器及多采樣時(shí)間光子相關(guān)器的結(jié)構(gòu)和優(yōu)缺點(diǎn)。 (2)采用FPGA設(shè)計(jì)了雙光子計(jì)數(shù)器對(duì)光子脈沖信號(hào)進(jìn)行交替計(jì)數(shù),實(shí)現(xiàn)了無縫隙光子計(jì)數(shù)；利用DSP片內(nèi)大容量存儲(chǔ)器設(shè)計(jì)了環(huán)形移位寄存器,實(shí)現(xiàn)了大動(dòng)態(tài)范圍比例相關(guān)器；PC機(jī)和DSP之間通過USB接口進(jìn)行數(shù)據(jù)傳遞；提出了比例相關(guān)器中通道延遲時(shí)間的計(jì)算公式；分析了相關(guān)函數(shù)的歸一化方法。 (3)分析了多采樣時(shí)間相關(guān)器的工作原理；采用FPGA設(shè)計(jì)實(shí)現(xiàn)了高速多采樣時(shí)間相關(guān)器,其核心模塊為相關(guān)運(yùn)算模塊,由移位寄存器、乘法器、累加器以及數(shù)據(jù)類型轉(zhuǎn)換器組成,各部分均采用Verilog語(yǔ)言編程實(shí)現(xiàn)；研究了相關(guān)函數(shù)的三角平均影響及相關(guān)函數(shù)的歸一化方法。 (4)基于DSP的比例相關(guān)器擴(kuò)展了動(dòng)態(tài)范圍,基于FPGA設(shè)計(jì)了相關(guān)器的高速相關(guān)運(yùn)算通道,提高了相關(guān)運(yùn)算速度,采用DSP+FPGA相結(jié)合的結(jié)構(gòu)實(shí)現(xiàn)了大動(dòng)態(tài)范圍高速光子相關(guān)器。 (5)采用本文設(shè)計(jì)的大動(dòng)態(tài)范圍高速光子相關(guān)器組成光子相關(guān)光譜顆粒測(cè)量裝置,在25℃溫度下,分別對(duì)60、150、200、300及450nm五種標(biāo)準(zhǔn)聚苯乙烯顆粒進(jìn)行了實(shí)測(cè)。測(cè)量結(jié)果表明,本文設(shè)計(jì)的相關(guān)器能夠提高測(cè)量結(jié)果的準(zhǔn)確性,選擇合適的采樣間隔和動(dòng)態(tài)范圍可使測(cè)量結(jié)果的相對(duì)誤差小于5%,重復(fù)性誤差小于3%,完全滿足納米顆粒測(cè)量的需要。 本文在研究光子相關(guān)光譜理論、光子相關(guān)器結(jié)構(gòu)和相關(guān)函數(shù)的歸一化方法基礎(chǔ)上,采用DSP+FPGA相結(jié)合的結(jié)構(gòu)實(shí)現(xiàn)了大動(dòng)態(tài)范圍高速光子相關(guān)器,最小采樣間隔為100ns,實(shí)現(xiàn)的動(dòng)態(tài)范圍可達(dá)1010。
[Abstract]:As the main method to measure the particle size and its distribution, photon correlation spectroscopy has been widely used in the field of nano-particle measurement. Photon correlator is the core device of photon correlation spectrum measurement system. The time autocorrelation function of scattered light intensity is obtained by counting photon pulses and performing real-time autocorrelation operation. At present, most of the photon correlators used in China are imported products. Therefore, the design and development of large dynamic range high-speed photon correlators with independent intellectual property rights has important economic and social benefits. In this paper, we focus on expanding the dynamic range of correlator and improving the speed of correlator operation and the normalization precision of correlation function. The following work has been done: (1) based on the theory of photon correlation spectrum, the linear photon correlator is studied, and the linear photon correlator is studied. The structure, advantages and disadvantages of proportional photon correlator and multisampling time photon correlator. (2) the two-photon counter is designed with FPGA to count the photon pulse signal alternately, and the gap-free photon count is realized, the loop shift register is designed by using the large-capacity memory in DSP chip, and the proportional correlator with large dynamic range is realized. The data transfer between PC and DSP is carried out through USB interface, the formula of channel delay time in proportional correlator is proposed, and the normalization method of correlation function is analyzed. (3) the working principle of multi-sampling time correlator is analyzed. The high-speed multi-sampling time correlator is designed and implemented with FPGA. The core module of the correlator is the correlation operation module, which consists of shift register, multiplier, accumulator and data type converter. Each part is programmed in Verilog language. The influence of trigonometric mean of correlation function and the normalization method of correlation function are studied. (4) the proportional correlator based on DSP extends the dynamic range, designs the high-speed correlation channel of the correlator based on FPGA, improves the speed of correlation operation, and realizes the high-speed photon correlator with large dynamic range by using the structure of DSP FPGA. (5) using the high-speed photon correlator designed in this paper, five kinds of standard polystyrene particles (60150 200300 and 450 nm) were measured at 25 鈩，

本文編號(hào)：2444216