多光通道条纹投影系统误差测量与补偿

基于相位计算的多通道三维测量技术由于同时使用多个光通道,通道间串扰和色差、镜头畸变以及器件非线性响应等多种误差耦合在一起,影响测量效果和检测精度.针对该问题,从采集图像的误差类型出发,将误差分为图像像素亮度与实际亮度之间的光强误差和图像像素空间分布的位置偏差,以此分别构建了光强误差关系和位置偏差关系并对检测系统进行定量测量.最后提出一种系统误差补偿方法,利用建立的误差关系修正了采集图像光强亮度和像素位置偏差,同时补偿了上述误差对测量结果的影响.实验结果表明,利用本文提出的误差补偿方法对标准台阶进行多通道三维形貌测量,测量误差从0.678 mm减小到0.031 mm,该方法对此类系统的高精度三维测量具有实用价值.

Error Measurement and Compensation of Multi-channel Fringe Projection System

Multi-channel three-dimensional measurement based on phase calculation uses multiple optical channels at the same time,which results in the coupling of crosstalk,chromatic aberration,lens distortion and nonlinear response of devices,and affects measurement results and detection accuracy. Aiming at this problem,based on the error types of the collected images,the errors are divided into the light intensity error between the image pixel brightness to the actual brightness and the position deviation of spatial position distribution of image pixels. Then the light intensity error relation and the position deviation relation are constructed respectively and carry on the quantitative measurement to the detection system.Finally,a systematic error compensation method is proposed,which corrects the errors of intensity and pixel position of the collected image by using the established error relation,and compensates the influence of the above errors on the measurement results. The error compensation method proposed in this paper is used in multi-channel three-dimensional measurement of a standard step,the experimental results show that the measurement error can be reduced from 0.678 mm to 0.031 mm,and the method has practical value for the high-precision three-dimensional measurement of such a system.