摘 要: 研究了基于大尺寸視覺測量系統的結構參數優化問題,圖像傳感器CCD外部姿態的優化布局可以提高測量精度。建立雙目視覺測量系統結構的數學模型,對有效視場約束條件進行了數學描述。利用Matlab軟件對不同結構參數進行仿真計算,結果表明被測點越靠近有效視場中心測量誤差越小,而基線距越大以及基線與光軸夾角越大所產生的誤差越大。最后,通過試驗驗證了攝像機外部姿態的誤差影響特征正確性,從而為雙目視覺測量系統的現場布置方法提供了依據。
關鍵詞: 視覺測量; 雙目視覺; 有效視場; 結構參數; 精度分析
中圖分類號: TN919?34; TP302.7 文獻標識碼: A 文章編號: 1004?373X(2013)24?0059?04
Analysis and experiment of structural parameters for large?scale vision measuring system
YU Zhi?jing1, ZHOU Huan2
(1. Aviation Ground Special Equipments Research Base, Civil Aviation Administration of China, Tianjin 300300, China;
2. College of Aeronautical Automation, Civil Aviation University of China, Tianjin 300300, China)
Abstract: The optimization of structural parameters for large?scale vision measuring system was investigated to find out the optimal layout of image sensor CCD external attitude, which can improve the accuracy of vision measurement. A mathematical model was established for the structural parameters of binocular vision measuring system. The mathematical description of constraint conditions for the effective field was conducted. The parameters of different structures were calculated with Matlab simulating software. The results show that the closer the measured point is to the effective FOV center, the less the measurement error becomes; the more the base line distance and the included angle between base line and optic axis increase, the more the measurement error is. The rationality of parameter optimization methods to set camera external attitude was verified by experiment.
Keywords: vision measurement; binocular vision; effective field of view; structural parameter; accuracy analysis
0 引 言
人們不斷增長的物質文化需要推動著科學技術和工業生產的發展,促使了對制造業提出的新要求。零部件尤其是大尺寸工件的表面越來越多地采用不規則復雜曲面,其設計、制造、檢測、控制和動態監測等環節都需要進行大量的三維測量。傳統的測量方法及設備很難滿足高效、經濟、全尺寸的測量要求:如三坐標測量機和激光跟蹤儀雖具有較高的測量精度,但都屬于接觸式測量并且比較笨重不便于移動,在測量過程中存在接觸力,需要對測頭半徑進行補償,且難以實現某些特殊結構和柔性材料的測量;經緯儀能提供較高的測量精度且可以方便移動,但都是逐點測量需要多次改變架設位置、操作復雜,故而工作效率較低;激光雷達測距測量精度高且功能豐富,但其成本較高,且測量精度容易受到震動等環境因素的影響。……