Atom tracking technology enhanced with innovative algorithms has been implemented in this study,utilizing a comprehensive suite of controllers and software independently developed domestically.Leveraging an on-board f...Atom tracking technology enhanced with innovative algorithms has been implemented in this study,utilizing a comprehensive suite of controllers and software independently developed domestically.Leveraging an on-board field-programmable gate array(FPGA)with a core frequency of 100 MHz,our system facilitates reading and writing operations across 16 channels,performing discrete incremental proportional-integral-derivative(PID)calculations within 3.4 microseconds.Building upon this foundation,gradient and extremum algorithms are further integrated,incorporating circular and spiral scanning modes with a horizontal movement accuracy of 0.38 pm.This integration enhances the real-time performance and significantly increases the accuracy of atom tracking.Atom tracking achieves an equivalent precision of at least 142 pm on a highly oriented pyrolytic graphite(HOPG)surface under room temperature atmospheric conditions.Through applying computer vision and image processing algorithms,atom tracking can be used when scanning a large area.The techniques primarily consist of two algorithms:the region of interest(ROI)-based feature matching algorithm,which achieves 97.92%accuracy,and the feature description-based matching algorithm,with an impressive 99.99%accuracy.Both implementation approaches have been tested for scanner drift measurements,and these technologies are scalable and applicable in various domains of scanning probe microscopy with broad application prospects in the field of nanoengineering.展开更多
针对传统特征检测算法检测效率低、匹配正确率低和双目视觉测量精度不足等问题,提出一种基于局部信息熵和梯度漂移的双目视觉测量算法。首先,将图像划分成若干子区域,计算各子区域局部信息熵筛选出高熵区域,并利用oriented FAST and rot...针对传统特征检测算法检测效率低、匹配正确率低和双目视觉测量精度不足等问题,提出一种基于局部信息熵和梯度漂移的双目视觉测量算法。首先,将图像划分成若干子区域,计算各子区域局部信息熵筛选出高熵区域,并利用oriented FAST and rotated BRIEF(ORB)算法检测特征点;其次,采用圆形邻域代替像素点,并对圆形邻域内各像素梯度幅值采用二维高斯加权的方式改进旋转不变local binary patterns(LBP);然后,与rotated binary robust independent elementary features(rBRIEF)融合生成新的描述子进行特征匹配;最后,提出梯度漂移方法,引入特征点次极大响应值作为辅助因素,结合极大响应值通过坐标迭代更新计算出理想特征点的精确坐标,解决提取特征点坐标不准确的问题,提高测量精度。实验结果表明:所提算法的平均匹配正确率较传统ORB算法提高37.51%,测量最低相对误差达到0.365%。展开更多
基金Project supported by the National Science Fund for Distinguished Young Scholars(Grant No.T2125014)the Special Fund for Research on National Major Research Instruments of the National Natural Science Foundation of China(Grant No.11927808)the CAS Key Technology Research and Development Team Project(Grant No.GJJSTD20200005)。
文摘Atom tracking technology enhanced with innovative algorithms has been implemented in this study,utilizing a comprehensive suite of controllers and software independently developed domestically.Leveraging an on-board field-programmable gate array(FPGA)with a core frequency of 100 MHz,our system facilitates reading and writing operations across 16 channels,performing discrete incremental proportional-integral-derivative(PID)calculations within 3.4 microseconds.Building upon this foundation,gradient and extremum algorithms are further integrated,incorporating circular and spiral scanning modes with a horizontal movement accuracy of 0.38 pm.This integration enhances the real-time performance and significantly increases the accuracy of atom tracking.Atom tracking achieves an equivalent precision of at least 142 pm on a highly oriented pyrolytic graphite(HOPG)surface under room temperature atmospheric conditions.Through applying computer vision and image processing algorithms,atom tracking can be used when scanning a large area.The techniques primarily consist of two algorithms:the region of interest(ROI)-based feature matching algorithm,which achieves 97.92%accuracy,and the feature description-based matching algorithm,with an impressive 99.99%accuracy.Both implementation approaches have been tested for scanner drift measurements,and these technologies are scalable and applicable in various domains of scanning probe microscopy with broad application prospects in the field of nanoengineering.
