For high precision calibration of camera with large field-of-view,massive calibration points will be needed if traditional methods are selected,which makes the calibration complex and time-consuming.In order to solve ...For high precision calibration of camera with large field-of-view,massive calibration points will be needed if traditional methods are selected,which makes the calibration complex and time-consuming.In order to solve this problem,a calibration method based on flexible planar target is proposed.In this method,distortion factor is firstly acquired by the invariance of cross ratio,and existing feature points are adjusted with the distortion factor.Then,a large number of points that will be used for the calibration are constructed with the adjusted feature points.Simultaneously,Tsai method is modified so as to reduce the complexity of calibration,which makes the process linear.The simulation and real experiments show that the method proposed in this paper is simple,linear,accurate and robust,and the precision of this method is close to that of Tsai method using abundant points.The method can satisfy the requirement of high precision calibration for camera with large field-of-view.展开更多
蝶形图是交流电磁场检测(alternating current field measurement,ACFM)中判定缺陷存在的一种重要方法。为研究常规裂纹蝶形图与裂纹剖面的映射关系,首先利用COMSOL Multiphysics实现不同尺寸裂纹的数值模拟,并建立了长度和深度特征量...蝶形图是交流电磁场检测(alternating current field measurement,ACFM)中判定缺陷存在的一种重要方法。为研究常规裂纹蝶形图与裂纹剖面的映射关系,首先利用COMSOL Multiphysics实现不同尺寸裂纹的数值模拟,并建立了长度和深度特征量的重构方程。其次通过对比,分析了蝶形图与裂纹剖面的内在关系,进一步结合图像处理法和常规线性拟合方法分别建立了两者的映射关系方程。最后,对Q235钢不同尺寸的槽状裂纹进行了检测试验。试验结果表明:基于长度和深度的裂纹剖面误差分别为5.46%和6.02%。该研究实现了蝶形图的再利用,为缺陷的风险评估方法提供了重要的参考。展开更多
A new type of philosophy from the view of pansystems is introducedhere,including the 7 philosophy theories(7PT),fuzziness research andmany second/third philosophies are developed within pansystems frame-work.
基金Sponsored by the Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.2014019)
文摘For high precision calibration of camera with large field-of-view,massive calibration points will be needed if traditional methods are selected,which makes the calibration complex and time-consuming.In order to solve this problem,a calibration method based on flexible planar target is proposed.In this method,distortion factor is firstly acquired by the invariance of cross ratio,and existing feature points are adjusted with the distortion factor.Then,a large number of points that will be used for the calibration are constructed with the adjusted feature points.Simultaneously,Tsai method is modified so as to reduce the complexity of calibration,which makes the process linear.The simulation and real experiments show that the method proposed in this paper is simple,linear,accurate and robust,and the precision of this method is close to that of Tsai method using abundant points.The method can satisfy the requirement of high precision calibration for camera with large field-of-view.
文摘蝶形图是交流电磁场检测(alternating current field measurement,ACFM)中判定缺陷存在的一种重要方法。为研究常规裂纹蝶形图与裂纹剖面的映射关系,首先利用COMSOL Multiphysics实现不同尺寸裂纹的数值模拟,并建立了长度和深度特征量的重构方程。其次通过对比,分析了蝶形图与裂纹剖面的内在关系,进一步结合图像处理法和常规线性拟合方法分别建立了两者的映射关系方程。最后,对Q235钢不同尺寸的槽状裂纹进行了检测试验。试验结果表明:基于长度和深度的裂纹剖面误差分别为5.46%和6.02%。该研究实现了蝶形图的再利用,为缺陷的风险评估方法提供了重要的参考。
文摘A new type of philosophy from the view of pansystems is introducedhere,including the 7 philosophy theories(7PT),fuzziness research andmany second/third philosophies are developed within pansystems frame-work.
