Research On Application Of Line Structured Light Technology In Logistics Sorting System

With the rapid development of e-commerce,the work of sorting packages has become more and more arduous.The traditional manual sorting method has the problems of low efficiency,low accuracy and increasing labor costs year by year.With the development of related technologies such as robotics and vision technology,various automatic sorting systems with high efficiency,high accuracy and low labor costs have gradually replaced manual sorting.This paper takes the design of a logistics automatic sorting system which based on the three-dimensional information of objects as the background to study its key technologies.The key of the logistics sorting system which based on three-dimensional information of objects lies in the measurement of three-dimensional information.Among the existing various 3D measurement technologies,the non-contact 3D measurement technology based on vision has the advantages of no damage to the measured object,wide measurement range and high measurement accuracy.Among them,the line structured light technology also has the advantages of low cost,good real-time performance and simple operation.Therefore,this article applies this technology to the logistics sorting system,and conducts related research and improvement on its key technologies.The main tasks are as follows:(1)The traditional light strip center extraction algorithm is studied.In the context of logistics sorting,aiming at the problem of low gray level,reflection interference and missing edges of light strip which caused by the characteristics of the package itself,by adding adaptive threshold segmentation,light stripe recognition,partition division,center point discrimination and balance adjustment strategies into gray barycenter method,an adaptive partition balance center of gravity method is proposed,which solves the above three problems well.(2)The light plane calibration method based on the invariance of cross-ratio is studied.In view of the limitations of this method of low point set utilization and easy deviation,a light plane calibration method based on non-coincident straight lines is proposed.By obtaining two laser lines which located at different positions to improve the point set utilization,and with the help of weighted overall least squares method,eliminates the points with large deviations.This method has the advantages of high flexibility and high reliability of calibration results.(3)Based on the C++ programming language,and under the development environment of Visual Studio 2015 and Qt Creator 5.8.0,a 3D measurement application program which based on improved algorithm is designed.(4)Selecting relevant hardware to build a three-dimensional measurement system as an experimental platform.Basing on this platform,six groups of measured experimental objects are measured multiple times,and error analysis on the measurement results is performed.The above experimental results shows that the line structured light three-dimensional measurement system which based on the improved algorithm has an absolute error of single measurement not more than 1.27 mm,and average absolute error of multiple measurements not more than 0.78 mm,which meets the accuracy requirements of the logistics sorting system and has high feasibility.