3D Reconstruction And Defect Detection System Of AGV High-speed Railway Body

Body is the most important large complex structural part of high-speed railway.Due to its large size,Because of the particularity of its shape,It is difficult to reconstruct its 3D morphology accurately and efficiently which greatly affects the subsequent automatic spraying and polishing process of high-speed railway body.Automated 3D reconstruction is the development trend of digital factory in the future,and the detection of defect area can also provide accurate position information for subsequent putty spraying and grinding.Therefore,this paper focuses on designing a three-dimensional reconstruction and defect detection system of AGV high-speed railway body.It is mainly aimed at the upper and lower cambered surface and side wall of the high-speed railway body,By combining the line laser sensor with the AGV mobile robot,the 3D reconstruction and defect detection of the high-speed train body are realized.The applicability and accuracy of the system are verified by simulation test.The main research contents are as follows:Firstly,the measurement requirements of high-speed railway body are analyzed.According to the measurement requirements,the selection of measuring equipment,the design of mobile robot,the construction of 3D reconstruction system,and the complete 3D reconstruction process is formulated;According to the measurement requirements,the overall path of the high-speed railway body is planned by using the transverse line-cutting scanning method;Based on the scanning model of Gocator2350 line laser sensor,the strategy of trapezoidal interception is proposed and the spatial position of the sensor is solved;According to the actual size of the high-speed railway body,the station task planning is adopted to scan and measure the high-speed railway body;In order to verify the effectiveness of the planned path in this paper,a simulation experiment was carried out in Robot Studio,taking the high-speed train body as an example.Secondly,a point cloud stitching method based on laser tracker is proposed for the characteristics of large size and high precision of high-speed railway body,In this method,the world coordinate system set by the laser tracker is used as the point cloud stitching coordinate system,and the 3D data collected by the sensor can be directly converted to the world coordinate system for point cloud data stitching,the mobile robot is only used as a mobile carrier instead of a link in the precision chain,which avoids the influence of the low positioning accuracy of the mobile robot on the system accuracy.Finally,the target surface defects are classified according to the detection requirements of high-speed railway body,and the minimum extraction standard of defects is established The point cloud data of the detection target is simulated and the caliper type measurement scheme is designed;The simulation experiment was built,Matlab was used for base surface fitting and defect extraction to verify the accuracy of the system.