Based On Line Structured Light Of Pantograph Slide Abrasion Detection System Research

With the rapid development of electrified railways,high-speed railways and urban mass transit have gradually become strong drivers of regional economies,and the regional economic benefits of rail transit have also become more prominent.It not only improves the travel convenience of local people,but also plays a key role in local economic development.In the process of train operation,pantograph is the key equipment for train drainage,and the carbon slide on it acts directly with the catenary network to ensure the stable current receiving and safe operation of the train.Therefore,it is necessary to research and design a wear detection system for carbon slide plate.In view of the low detection efficiency of traditional manual measurement and image method when detecting slide wear,it is difficult to timely and accurately evaluate the wear state of pantograph slide.At the same time,according to the existing relevant standards,a multi-vision sensor detection system is designed to carry out high-precision detection of pantograph carbon slide wear.In this thesis,the types of structured light technology and the generation principle of linear structured light are introduced at first,and on this basis,the coordinate system commonly used in vision measurement is expounded.Based on this,the direct linear transformation model of the camera is deduced.Considering the distortion of the camera lens,the nonlinear model of the camera is established.The mathematical model of linear structured light measurement is deduced,and the internal parameter calibration of the camera is studied and the laser plane equation is solved.Secondly,aiming at the characteristics of large transverse space of carbon slide plate of pantograph of train,a set of sliding plate wear detection system which is combined with multiple vision sensors is designed.Through the combination of three laser camera equipment,the measurement range is expanded to complete the data acquisition of the overall outline of the slide.And on the basis of a single vision sensor calibration,with intermediate vision sensors to build the global coordinate system,research the combination of the three vision sensors calibration method,to determine the relationship between position in the machine vision sensors in space.Then,on the basis of completing the calibration of multiple vision sensors,the overall outline of the slide and the point cloud outline of the metal support plate of the carbon slide are obtained.Because there is noise in the original point cloud data,it is necessary to carry out relevant filtering operation on the point cloud data of pantograph slide first,and remove large noise data through preprocessing.On this basis,the collected point cloud data is simplified.Based on the research of point cloud simplification algorithm,a density clustering method based on voxel raster is proposed.The core idea is to use DBSCN algorithm to segment the point cloud data of the target area and get the point cloud data of the sliding plate plane and the supporting plate area.Finally,based on the plane fitting with the consistent random sampling,the plane where the two metal pallet contour is located is determined.By calculating the maximum distance between the point cloud data of the sliding plate and the pallet plane,the wear value of the sliding plate is obtained.Finally,based on the existing conditions of design for test in laboratory environment.Experimental results show that the designed by pantograph slide more visual sensor detection system detection accuracy can meet the test requirements,has the characteristics of good real-time,high precision,has a good application prospect.