基于交比不变性的十字形标定靶标及其识别方法

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关键词：相机标定；交比不变性；十字形靶标;大视场

中图分类号：TP394.1;TH691.9 文献标识码：A

Abstract：To address the challenges of manufacturing，portability，and deformation associated with traditional large-scale calibration targets in large field-of-view （FOV） measurements，a cross-shaped calibration target based on cros-ratio invariance and its recognition method was proposed. First，a cross-structured target was designed by vertically connecting two equal-length rulers. The target featured four arms of equal length，with circular uncoded markers arranged along each arm such that the cross-ratio among any four adjacent points remained constant at 4/3 . The main structure was made of aluminum alloy or carbon fiber composite material，ensuring both lightweight and high strength. Second，a marker encoding rule was developed based on the principle of cross-ratio invariance，and a recognition algorithm was designed to enable automatic detection and decoding of target points in calibration images. Finally，a physical prototype of the target was fabricated and tested.Experimental results demonstrate that the proposed target can be accurately recognized even at a large tilt angle ofup to 80∘ ，and its simple structure makes it easy to manufacture，assemble，disassemble，and carry，making it wel-suited for rapid calibration of wide FOV cameras in complex industrial environments.

Key words： camera calibration；cross-ratio invariance；cros-shaped calibration target；large fields of view

1引言

3D视觉技术凭借其高精度、高效率以及非接触式的独特优势，已经在外形轮廓检测、结构变形分析、人脸识别、智能机器人和自动驾驶等工业自动化领域得到了广泛应用。（剩余16496字）