【正文】 三維激光掃描技術(shù)(3D Laser Scanning Technology)是一種先進的全自動高精度立體掃描技術(shù)。橋梁變形監(jiān)測方面，傳統(tǒng)監(jiān)測方法是通過連續(xù)和定期的單點觀測，對多期觀測數(shù)據(jù)進行對比分析，完成對工程安全性的確定，通過對離散監(jiān)測點位移變化分析，做出安全與評價，其結(jié)論可能存在較多的片面性和不確定性。交通建設(shè)迅速發(fā)展，交通運輸大幅度提高，行車密度及車輛載重越來越大，跨河橋梁和高架橋梁對交通運輸和經(jīng)濟發(fā)展的重要性不斷增加，同時產(chǎn)生的一系列橋梁工程問題日益突出。目 錄摘 要 ..............................................................................................................................IABSTRACT.................................................................................................................II目 錄 ...........................................................................................................................III第一章 緒論 ..................................................................................................................1 課題研究背景及意義 .............................................................................................................1 國內(nèi)外研究現(xiàn)狀 .....................................................................................................................2 國外研究現(xiàn)狀 ..................................................................................................................3 國內(nèi)研究現(xiàn)狀 ..................................................................................................................5 當前研究的不足 ..............................................................................................................7 本文主要研究內(nèi)容及技術(shù)路線 .............................................................................................7 本文研究內(nèi)容 ..................................................................................................................7 本文技術(shù)路線 ..................................................................................................................8 論文組織結(jié)構(gòu) .......................................................................................................................10第二章 三維激光掃描系統(tǒng)及影響點云精度因素分析 ............................................11 地面三維激光掃描系統(tǒng)分類及性能指標 ...........................................................................11 地面三維激光掃描系統(tǒng)分類 ........................................................................................11 地面三維激光掃描儀性能指標 ....................................................................................13 地面三維激光掃描系統(tǒng)原理 ...............................................................................................14 三維激光掃描系統(tǒng)的組成 ............................................................................................14 地面三維激光掃描系統(tǒng)原理 ........................................................................................15 實驗儀器介紹 .......................................................................................................................18 Trimble GXTM 三維激光掃描系統(tǒng)介紹 ........................................................................18 Trimble GXTM 三維激光掃描系統(tǒng)軟件 ........................................................................19 Trimble GXTM 三維激光掃描數(shù)據(jù)格式 ........................................................................21 影響點云精度因素分析 .......................................................................................................21 測量距離和角度影響 ....................................................................................................22 點云厚度與亮度影響 ....................................................................................................22 目標物體反射表面粗糙程度的影響 ............................................................................23 邊緣效應(yīng) ........................................................................................................................24 激光光束不均勻 ............................................................................................................25 外界環(huán)境的影響 ............................................................................................................26 實驗結(jié)果分析 .......................................................................................................................27 本章小結(jié) ...............................................................................................................................32第三章 橋梁監(jiān)測方案設(shè)計與數(shù)據(jù)預(yù)處理研究 ........................................................33 橋梁變形監(jiān)測方案設(shè)計 .......................................................................................................33 變形監(jiān)測方案流程 ........................................................................................................33 點云數(shù)據(jù)獲取步驟 ........................................................................................................35 橋梁變形監(jiān)測數(shù)據(jù)預(yù)處理 ...................................................................................................36 點云數(shù)據(jù)去噪 ................................................................................................................36 特征點坐標轉(zhuǎn)換 ............................................................................................................37 點云數(shù)據(jù)配準 ................................................................................................................42 實驗結(jié)果分析 .......................................................................................................................44 本章小結(jié) ...............................................................................................................................48第四章 基于點云的橋梁變形分析方法研究 ............................................................49 基于曲面擬合的橋梁變形研究 ...........................................................................................49 平面以及二次曲面擬合 ................................................................................................49 基于曲面擬合的變形分析方法 ....................................................................................53 實驗結(jié)果分析 ................................................................................................................54 基于 ICP 配準算法的橋梁變形提取 ...................................................................................56 ICP 配準算法原理 ...................................................................