超寬帶雷達(dá)人體目標(biāo)檢測(cè)與跟蹤
發(fā)布時(shí)間:2018-03-14 06:18
本文選題:超寬帶雷達(dá) 切入點(diǎn):人體目標(biāo) 出處:《國(guó)防科學(xué)技術(shù)大學(xué)》2014年碩士論文 論文類型:學(xué)位論文
【摘要】:短距離人體跟蹤在安全領(lǐng)域應(yīng)用上非常重要,比如機(jī)場(chǎng)安檢、穿墻偵察恐怖分子、廢墟中搶救受困人員。超寬帶(Ultra-Wideband,UWB)雷達(dá)良好的距離分辨力和穿透能力,使其非常適合短距離人體跟蹤。另一方面,工作環(huán)境的特殊性對(duì)超寬帶雷達(dá)在目標(biāo)檢測(cè)、鑒別和跟蹤方面提出了更高的要求。為此,本文將超寬帶雷達(dá)對(duì)人體目標(biāo)的檢測(cè)和跟蹤作為研究的重點(diǎn)。論文首先介紹了超寬帶雷達(dá)的系統(tǒng)組成、信號(hào)體制及信號(hào)處理流程,詳細(xì)分析了超寬帶雷達(dá)常用的四種信號(hào),并主要介紹了耦合對(duì)齊,背景相消,以及多徑效應(yīng)抑制三個(gè)問(wèn)題。其中,耦合對(duì)齊能夠提高背景相消抑制耦合強(qiáng)雜波的性能,指數(shù)加權(quán)背景相消則能夠?qū)较蚝头菑较蜻\(yùn)動(dòng)的目標(biāo)都有較好的動(dòng)目標(biāo)指示性能,利用時(shí)間窗可將多徑和雜波從目標(biāo)回波中分離出來(lái)。動(dòng)目標(biāo)指示后進(jìn)行的目標(biāo)檢測(cè),主要目的就是判斷目標(biāo)有無(wú)。傳統(tǒng)的恒虛警檢測(cè)(Constant False Alarm Rate,CFAR)方法對(duì)單個(gè)人體目標(biāo)檢測(cè)時(shí),為使目標(biāo)信息得到很好的保留,往往需要設(shè)置相對(duì)較高的虛警概率,但同時(shí)背景雜波也會(huì)隨之增多;而在對(duì)多個(gè)相距很近,甚至交叉、重疊時(shí)的人體目標(biāo)進(jìn)行檢測(cè)時(shí),會(huì)出現(xiàn)嚴(yán)重的目標(biāo)遮蔽現(xiàn)象。為此,本文提出將通常用于圖像處理的CLEAN算法用于超寬帶雷達(dá)人體目標(biāo)檢測(cè)中,相比CFAR算法,CLEAN算法對(duì)不同運(yùn)動(dòng)狀態(tài)下的單個(gè)、多個(gè)人體目標(biāo)均有較好的檢測(cè)性能,且能夠有效的抑制雜波、多徑和目標(biāo)遮蔽、自遮蔽現(xiàn)象,并能夠很好的保留目標(biāo)的信息,提取出人體多個(gè)散射點(diǎn)并記錄下每個(gè)散射點(diǎn)的到達(dá)時(shí)延。本文基于人體多散射點(diǎn)的回波模型,利用CLEAN算法提取出人體多個(gè)散射點(diǎn)的量測(cè)信息后,結(jié)合最近鄰數(shù)據(jù)關(guān)聯(lián)算法和聯(lián)合概率數(shù)據(jù)關(guān)聯(lián)算法,分別實(shí)現(xiàn)了對(duì)單個(gè)、多個(gè)人體目標(biāo)的距離軌跡跟蹤;并針對(duì)聯(lián)合概率數(shù)據(jù)關(guān)聯(lián)算法在回波數(shù)目增多時(shí)計(jì)算量易出現(xiàn)爆炸現(xiàn)象的問(wèn)題,提出一種改進(jìn)的聯(lián)合概率數(shù)據(jù)關(guān)聯(lián)算法。該方法不僅實(shí)現(xiàn)了對(duì)軌跡交叉的多個(gè)人體目標(biāo)的有效跟蹤,而且通過(guò)與聯(lián)合概率數(shù)據(jù)關(guān)聯(lián)算法性能比較,二者的性能相當(dāng),但計(jì)算量卻大大減少。
[Abstract]:Short-range human tracking is very important in security applications, such as airport security, detection of terrorists through walls, rescue of trapped people from debris. UWB Ultra-Wideband UWBradar has good range resolution and penetration capability. It is very suitable for short range human body tracking. On the other hand, the particularity of working environment puts forward higher requirements for UWB radar in target detection, identification and tracking. This paper focuses on the detection and tracking of human body target by UWB radar. Firstly, the system composition, signal system and signal processing flow of UWB radar are introduced, and four kinds of signals commonly used in UWB radar are analyzed in detail. Three problems, namely coupling alignment, background cancellation, and multipath effect suppression, are introduced, in which coupling alignment can improve the performance of background cancellation and suppression of coupled strong clutter. Exponential weighted background cancellation can indicate both radial and non-radial moving targets, and multipath and clutter can be separated from target echo by time window. The main purpose is to judge the existence or absence of target. When the traditional constant False Alarm CFAR method is used to detect a single human target, it is necessary to set a relatively high false alarm probability in order to keep the target information well. But at the same time, the background clutter will also increase, and in the detection of a number of close, even cross, overlapping human targets, there will be a serious target masking phenomenon. In this paper, CLEAN algorithm, which is usually used in image processing, is applied to human body target detection of UWB radar. Compared with CFAR algorithm, clear algorithm has better detection performance for multiple human body targets under different moving states. And can effectively suppress clutter, multi-path and target masking, self-masking phenomenon, and can very well retain the information of the target, Multiple human scattering points are extracted and the arrival delay of each scattering point is recorded. Based on the echo model of human body multiple scattering points, the measurement information of human body multiple scattering points is extracted by using CLEAN algorithm. Combined with nearest neighbor data association algorithm and joint probabilistic data association algorithm, the distance trajectory tracking of single or multiple human objects is realized respectively. The joint probabilistic data association algorithm is prone to explosion when the number of echoes increases. An improved joint probabilistic data association algorithm is proposed, which not only realizes the effective tracking of multiple human objects whose tracks are crossed, but also compares the performance of the joint probabilistic data association algorithm with that of the joint probabilistic data association algorithm. But the amount of calculation is greatly reduced.
【學(xué)位授予單位】:國(guó)防科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2014
【分類號(hào)】:TN953
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本文編號(hào):1610004
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