基于一般成像模型的微小物体测量系统标定方法

Calibration Method Based on General Imaging Model for Micro-Object Measurement System

通过利用光栅投影三维测量技术进行微小物体的三维重构,提出了基于一般成像模型的标定方法,利用标定板围绕固定轴转动的不同姿态进行标定并进行优化。所提出的标定算法既解决了一般成像模型变量多的问题,又不需要借助精密位移装置,简化了整个标定过程。与此同时,利用自卷积盲去模糊的方法解决远心镜头景深小带来的离焦,提高了摄像机的标定精度。标定和三维重构实验验证了该方法的可行性和准确性。在23.7 mm×17.78mm相机视场范围下系统测量精度达到了6μm。

The calibration method based on generaI imaging model is proposed by using the grating projection three- dimensional measuring technology for three-dimensional reconstruction of small objects. Different poses of the calibration target rotating around the fixed axis are utilized to calibration and optimization. The proposed calibration method solves the problems of general imaging model variables and does not need to use precision displacement device. In the meanwhile, a self convolution blind deblurring method is used to solve the defocus caused by small depth of field of the telecentric lens, and improves the calibration accuracy of camera. The feasibility and veracity of the proposed method are demonstrated with experiments of calibration and three-dimensional reconstruction. The measurement accuracy achieves 6 μm when the camera field of view is 23.7 mm× 17.78 mm.