本文選題：虛擬大平面靶標(biāo) + 小尺寸靶標(biāo)組合�。� 參考：《南昌航空大學(xué)》2017年碩士論文

【摘要】：基于立體視覺(jué)的測(cè)量系統(tǒng)被廣泛應(yīng)用于工業(yè)、農(nóng)業(yè)、國(guó)防等領(lǐng)域,攝像機(jī)標(biāo)定是其關(guān)鍵步驟,標(biāo)定的精度直接決定整個(gè)測(cè)量系統(tǒng)的精度,因此,研究高精度的攝像機(jī)標(biāo)定技術(shù)對(duì)提高立體視覺(jué)測(cè)量系統(tǒng)的精度具有重要意義。本課題組在開(kāi)展直升機(jī)旋翼槳葉運(yùn)動(dòng)參數(shù)測(cè)量研究時(shí),發(fā)現(xiàn)傳統(tǒng)較高精度的攝像機(jī)標(biāo)定方法在大視場(chǎng)環(huán)境下,標(biāo)定精度不理想。據(jù)此,本文分析了影響基于立體視覺(jué)大視場(chǎng)攝像機(jī)標(biāo)定精度的影響機(jī)理,采用虛擬大平面靶標(biāo)(Virtual Large Planar Target,簡(jiǎn)稱VLPT)研究了大視場(chǎng)攝像機(jī)標(biāo)定技術(shù),并系統(tǒng)分析了標(biāo)定精度的影響因素。主要工作內(nèi)容及其研究成果如下:(1)構(gòu)建了大視場(chǎng)攝像機(jī)標(biāo)定方法的實(shí)驗(yàn)驗(yàn)證系統(tǒng)。根據(jù)標(biāo)定方法的驗(yàn)證要求,分別從硬件、軟件和靶標(biāo)三個(gè)方面,設(shè)計(jì)出實(shí)驗(yàn)驗(yàn)證系統(tǒng)。硬件平臺(tái)包括視覺(jué)模塊和數(shù)據(jù)處理模塊;軟件平臺(tái)分為圖像采集模塊、攝像機(jī)標(biāo)定模塊和標(biāo)定精度測(cè)試模塊;分別從靶標(biāo)的類型、標(biāo)記點(diǎn)的類型、標(biāo)定點(diǎn)的個(gè)數(shù)、靶標(biāo)的定位、標(biāo)定點(diǎn)的排序五個(gè)方面,設(shè)計(jì)出8*8圓形標(biāo)記點(diǎn)二維,且?guī)в邪袠?biāo)定位點(diǎn)和排序定向點(diǎn)的靶標(biāo)。該實(shí)驗(yàn)驗(yàn)證系統(tǒng)為驗(yàn)證本文方法的有效性和分析標(biāo)定精度的影響因素提供基礎(chǔ)保障。(2)提出了基于VLPT的大視場(chǎng)攝像機(jī)標(biāo)定方法。首先,利用多個(gè)相互獨(dú)立的小尺寸靶標(biāo)(Mutually Independent Small Target,簡(jiǎn)稱MIST),獲取多張標(biāo)定圖像;其次,針對(duì)每張標(biāo)定圖像,采用定位標(biāo)記點(diǎn)圓心的方法,找到各個(gè)MIST,并為其上標(biāo)定點(diǎn)進(jìn)行排序和編號(hào);再次,設(shè)定虛擬平面,通過(guò)在該平面上找到每個(gè)標(biāo)定點(diǎn)對(duì)應(yīng)虛擬點(diǎn)的方式,將多個(gè)MIST聯(lián)系到一起,構(gòu)造出每張標(biāo)定圖像相應(yīng)的VLPT;接著,利用已獲得的多個(gè)VLPT,計(jì)算出攝像機(jī)參數(shù),并通過(guò)非線性優(yōu)化算法對(duì)標(biāo)定參數(shù)進(jìn)行全局優(yōu)化;最后,將本文方法與傳統(tǒng)標(biāo)定方法進(jìn)行對(duì)比實(shí)驗(yàn),結(jié)果表明:本文方法的標(biāo)定精度,與大尺寸靶標(biāo)的標(biāo)定精度相近,且明顯高于小尺寸靶標(biāo)的標(biāo)定精度。(3)分析了VLPT標(biāo)定方法精度的影響因素。根據(jù)研究本文方法的過(guò)程,分別從標(biāo)記點(diǎn)的定位精度、靶標(biāo)的擺放方式、MIST的大小、標(biāo)定圖像對(duì)的數(shù)目四個(gè)方面分析其對(duì)標(biāo)定精度的影響機(jī)理,采用理論分析與實(shí)驗(yàn)驗(yàn)證相結(jié)合的方式,得出了以下結(jié)論:1)標(biāo)記點(diǎn)的定位精度對(duì)標(biāo)定參數(shù)的獲取過(guò)程影響不大,但嚴(yán)重影響了待測(cè)點(diǎn)的三維信息計(jì)算結(jié)果;2)通過(guò)“米字”形擺放方式,選取靶標(biāo)面積為245mm*245mm的MIST,通過(guò)8對(duì)標(biāo)定圖像,可以獲得較高的標(biāo)定精度。這為本文方法的合理使用提供了指導(dǎo)性的建議,進(jìn)一步提高了本方法的標(biāo)定精度。
[Abstract]:The measurement system based on stereo vision is widely used in the fields of industry, agriculture, national defense and so on. Camera calibration is the key step. The precision of calibration directly determines the accuracy of the whole measurement system. It is very important to study the camera calibration technology with high precision to improve the precision of stereo vision measurement system. In the research of helicopter rotor blade motion parameter measurement, our group found that the traditional camera calibration method with high accuracy is not ideal in large field of view. Based on this, this paper analyzes the influence mechanism of camera calibration based on stereo vision, and studies the calibration technology of large field camera by using Virtual Large Planar Target, a virtual large plane target. The influencing factors of calibration accuracy are analyzed systematically. The main work and research results are as follows: 1) an experimental verification system for large field camera calibration method is established. According to the verification requirements of calibration method, the experimental verification system is designed from three aspects: hardware, software and target. The hardware platform includes visual module and data processing module, the software platform is divided into image acquisition module, camera calibration module and calibration precision testing module. There are five aspects in the ranking of marked points, and the two dimensional target with target location and sort orientation point is designed for 8 ~ (8) circular marking points. The experimental verification system provides a basic guarantee for verifying the effectiveness of the proposed method and analyzing the factors affecting the calibration accuracy. (2) A large field of view camera calibration method based on VLPT is proposed. Firstly, multiple calibrated images are obtained by using several independent small Independent Small targets (MISTs). Secondly, for each calibrated image, the method of locating the center of the mark point is used. Find each MIST, sort and number its superscript points; third, set the virtual plane, and associate multiple MIST together by finding the corresponding virtual point of each marker point on that plane. The corresponding VLPTs of each calibrated image are constructed. Then, the camera parameters are calculated by using the obtained VLPTs, and the calibration parameters are optimized globally by nonlinear optimization algorithm. The experimental results show that the calibration accuracy of this method is similar to that of large scale target. The accuracy of VLPT calibration method is obviously higher than that of small size target. According to the process of studying the method in this paper, the mechanism of influence on calibration accuracy is analyzed from four aspects: the positioning accuracy of marking points, the size of MIST and the number of calibrated image pairs. By combining theoretical analysis with experimental verification, it is concluded that the accuracy of tagging points has little effect on the acquisition of calibration parameters. However, the result of 3D information calculation is seriously affected. By means of "meter word" arrangement, the high calibration accuracy can be obtained by selecting 245mm*245mm whose target area is 245mm*245mm, and by using 8 pairs of calibrated images. This provides guidance for the rational use of this method and further improves the calibration accuracy of the method.
【學(xué)位授予單位】：南昌航空大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TP391.41

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 呂耀文;劉維;徐熙平;安U，

本文編號(hào)：1779834