Research On Three-dimensional Reconstruction System Based On Line Laser Scanning

At present,the research of 3D measurement technology mainly focus on small objects.The methods include machine vision method and structured light method.The machine method relies on the realization of matching algorithm.But the calculation of visual matching algorithm is complex,and it's not suitable for the scanning measurement technology,either.The optical measurement methods,such as coded light method and projection grating method,have high accuracy,but the environmental requirements are so harsh that most scenes cannot be applied.The environmental requirements of point laser scanning technology are easy to be satisfied,so it can be applied to most scenes,and also has high accuracy.But its speed is slow and the efficiency is extremely low because it measures point by point.This paper focus on the 3D measurement and reconstruction of scene.The line laser 3D scanning measurement and reconstruction system is proposed based on the technology of the point laser scanning system.Based on the principle of laser triangulation,a scanning measurement method is proposed in this paper.The transformation equation is constructed by the relative position relationship between the camera optical axis and the laser axis.And the problem of multi-point matching in line laser scanning measurement is solved.The parameters of system are calibrated on the basis of the least square method.And the effect of each parameter on the measurement error is analyzed through error analysis,and some suggestions for improving the measurements' precision are put forward.This paper not only studies the noise source,but also studies the reliability evaluation of the extraction of the fringe in the part of image processing.In the experimental part,the reliability of the system is verified by scene reconstruction experiment,and the accuracy of distance measurement and dimension measurement of the system are verified by precision evaluation experiment.The experiments show that the distance error of the system measurement is less than 2.6 mm and the relative error is better than 0.25%,and the dimensional error is less than 0.32 mm in the measurement range of 1000-1700 mm which satisfy the requirements for the general scenes reconstruction.