Application Of Industrial Photogrammetry In Intelligent Detection System Of CRTS? Track Slab

CRTS? track slab is an important symbol for the localization of Chinese high-speed railway ballastless track technology.It has been widely used in the construction of high-speed railways in China.The manufacturing precision of track slab has an important influence on the structure performance and geometry of track slab.As the last necessary quality assurance procedure before leaving the factory,the detection of the track slab's dimension is of great significance to ensure the high safety,high smoothness,high stability and high reliability of high-speed railway.Based on the research of existing CRTS? track slab detection methods and systems at home and abroad,combined with industrial photogrammetry which has the advantages of simple equipment,flexible measurement method,low cost and wide range,this paper applied industrial photogrammetry technology to the correction of frame coordinates for the intelligent detection system of CRTS? track slab.Intelligent Detection System for Dimension of CRTS? Track Slab of High-speed Railway(CRTS?_IDS)was designed and its prototype system was realized.CRTS?_IDS integrates key equipments such as general industrial robot,photographic 3D scanner,industrial photogrammetry system and standard ruler.According to the functions,it is divided into INspection System,Checking And Correction System,DataBase Management System.INspection System is the core working system of CRTS?_IDS,which uses the “pre-configured parameters” to improve the visualization and integration of the track slab surface's point cloud data acquisition and pre-processing.Checking And Correction System consists of Checking system,Frame Correction System and Parameter Calculation System for checking and correcting INspection System.Checking system is realized by a selfdesigned standard ruler;Based on the industrial photogrammetry system,Frame Correction System uses coded targets as carriers and establishs the frame coordinate system of the track slab;Parameter Calculation System acquires the conversion parameters of the track slab characteristic parts' point cloud to the frame coordinate system,and provides the reference data for the point cloud splicing.The frame coordinate control point and the industrial photogrammetry network of the track slab were designed with the coded targets and the ordinary digital camera,and the 3D reconstruction accuracy of the frame coordinate points were verified by the standard ruler.By analyzing the influencing factors of CRTS ?_IDS measurement accuracy,a simple verification method of repeated positioning accuracy of industrial robots was proposed and applied,and the applicability of industrial robots in CRTS?_IDS was proved.Using the general 3D measurement software platform,the program realized the automatic acquisition of each feature position conversion parameter.The CRTS?_IDS prototype system was realized with the conversion parameters.Based on the rigorous mathematical model,using the standard ruler,the accuracy evaluation method of the detection system of track slab was proposed.Finally,using standard ruler and other detection methods,the reliability of point cloud data splicing and track slab detecting of CRTS?_IDS was verified,which indicated that the track slab's dimension met the requirements of high-speed railway construction.And the standard accuracy of CRTS?_IDS is 0.155mm/m,which ensures the quality of the track slab before leaving the factory.