Research On Three-dimensional Reconstruction Method Of Highly Reflective Objects With Adaptive Binocular Stripe Projection

Stripe projection three-dimensional measurement technology is currently a widely used three-dimensional measurement technology,with its advantages of non-contact,high precision and high measurement efficiency,it is more widely used in industry,health care,3D printing and other fields.However,when measuring objects with high reflectivity,in the areas of high reflection and low reflection,the collected modulated fringe image will be saturated with pixels or the fringe pattern will be too dark,which greatly reduces the accuracy of three-dimensional measurement.Therefore,it is of great significance and application value to study how to use fringe projection three-dimensional measurement technology to obtain more complete three-dimensional information of highly reflective objects.First of all,an adaptive binocular fringe projection method is proposed for the fringe image saturation caused by the surface highlighting of the measured object.This method establishes the functional relationship between the camera,the object and the projector.According to the light intensity of the projection sequence,the surface reflection characteristics of the object are obtained,and the optimal projection grayscale value is calculated.Through the relationship between binocular conversion and camera-projector conversion,the mapping of the grayscale value and the corresponding point grayscale value in the stripe image is corrected,so as to obtain a high-quality projection fringe image and improve the three-dimensional reconstruction accuracy.Secondly,a multi-frequency heterodyne phase compensation method is proposed for the problem of jumping error in the phase development of the multi-frequency heterodyne method.According to the relationship between the root mean square error of the three frequency principal value functions and adjacent phases,this relationship is regarded as an additional condition for phase expansion,the jump phase is compensated,and the least squares threshold judgment model is established to continuously compensate the "hop point" with large error,and finally each frequency phase principal function can be expanded continuously.Several sets of experiments are designed using the built three-dimensional measurement platform,and the experimental results show that the adaptive binocular fringe projection method has a strong measurement ability for the hemisphere of aluminum alloy material,and the grayscale value of the adaptive correction projection fringe is realized.Through the flat plate measurement experiment and the hemispherical experiment of aluminum alloy material,the feasibility of the multi-frequency heterodyne phase compensation method is proved.At the same time,experiments of highly reflective objects made of plastic and ceramic materials are carried out,and the experimental results of different adaptive fringe methods are compared,and it is verified that the adaptive binocular fringe projection method has high accuracy for three-dimensional reconstruction of objects,and is suitable for objects with different materials and different surface reflectivity.