基于立体视觉的板料成形极限应变测量关键技术及其系统  

Key Techniques and System of Sheet Metal Forming Limit Strain Measurement Based on Stereo Vision

作　　者：叶南[1] 张丽艳[1] 

机构地区：[1]南京航空航天大学航空宇航制造工程系,江苏南京210016

出　　处：《航空学报》2010年第10期2093-2102,共10页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(50875130);教育部博士点基金(200802870016);江苏省科技支撑计划(BE2008136)

摘　　要：设计并实现了一种基于双目立体视觉和数字图像相关方法的板料成形极限应变测量系统—BOSAS(双目视觉应变测量分析系统),对其中的关键技术作了深入讨论。该系统可以克服传统坐标网格方法很难进行变形过程的动态监控、自动化程度不高等局限,并可计算试件各变形阶段全场应变分布,以及重建不同变形时刻下试件的几何外形。将分段位移传递法和有限应变理论相结合,可计算大变形下的极限应变。对深冲铝板6016以及航空铝板2A12-T4、2A12-O、7B04-O等材料的应变测量结果显示本文方法适用于板料成形三维变形及极限应变的测量,并将测得数据与由坐标网格方法测得的数据进行比较,结果表明本文方法测量准确、可靠。A sheet metal forming limit strain measurement system—BOSAS （binocular strain analysis measurement system） is designed and implemented,which is based on binocular stereo vision and digital image correlation method.The key techniques concerned are discussed in detail.The proposed method can break the limitations of the classical coordinate grid analysis method,such as difficult dynamic tracking of deformation process and low level automation,and can calculate whole-field strain distribution and reconstruct three-dimensional （3D） shape of the specimen’s surface in every stage during the whole deformation process.Limit strain is able to be calculated by the combination of the fractionized displacement transfer （FDT） algorithm and the finite strain theory.Strain measurement results of material varieties such as deep drawing aluminum sheet 6016,and aeronautical aluminum sheet 2A12-T4,2A12-O and 7B04-O demonstrate that the proposed method is applicable to the measurement of 3D deformation and limit strain of the sheet metal forming.Comparison of strain data obtained by BOSAS and by coordinate grid analysis method shows that the suggested method is accurate and reliable.

关 键 词：立体视觉 成形极限图 应变 数字图像相关 大变形 

分 类 号：V261.28[航空宇航科学与技术—航空宇航制造工程] TP391.41[自动化与计算机技术—计算机应用技术]