相位测量偏折术中高质量条纹的获取

High Quality Fringe Patterns Captured from Phase Measuring Deflectometry

相位测量偏折术中的相位误差主要分为CCD相机的随机误差以及由结构光照明光源与CCD相机的非线性响应导致的非线性误差。从影响相位误差的根源分析,建立了条纹质量与相位误差、相机镜头光圈数、编码条纹的周期、调制度等因素的分析模型,并对该模型的可靠性与正确性进行仿真与实验验证。理论分析、仿真与实验结果表明:获取条纹的对比度与相机镜头光圈数、编码条纹的周期和调制度成正比,获取条纹的正弦性与相机镜头光圈数、编码条纹的周期及调制度成反比。根据该条纹质量分析模型优化系统参数,可以获得高质量的条纹。该条纹质量分析模型同样适用于面结构光三维测量等其他技术。

The random error introduced by CCD camera and the nonlinear error caused by the nonlinear response function of illuminant and CCD camera are two main errors in phase measuring deflectometry. Based on the analysis of the factors affecting the phase error, we establish the analysis model of fringe pattern quality and the factors such as phase error, F value of camera lens, the period of coded fringe pattern, and modulation. The reliability and correctness of the proposed model are verified by computer simulation and experiment. The results of theoretical analysis, simulation, and experimental results show that the contrast ratio of the obtained fringe pattern is proportional to F value of the camera lens and the period and the modulation of the fringe pattern. The sinuousness of fringe is inversely proportional to F value of the camera lens and the period and the modulation of the generated fringe pattern. According to the proposed fringe quality analysis model, high quality fringe pattern can be obtained by optimizing the system parameters. The proposed model can apply to other techniques, such as surface-structured light three-dimensional measurement.