Research On Deformation Monitoring Technology Of Service Slope Surface Based On Digital Close-range Photogrammetry With Unmanned Aerial Vehicle

Aiming at the problems of low automation and intelligence,complex installation,damage to slope and others for the existing slope deformation monitoring technology,through the calibration of digital camera internal parameters and the development of deformation monitoring target,the Digital Close-range Photogrammetry technology with UAV(Unmanned Aerial Vehicle)is introduced into the service slope surface deformation monitoring by means of image processing,software development,experiment verification and so on in this thesis,so as to obtain a deformation monitoring technology suitable for the high slope in operating mountainous expressway.1)Through the establishment of outdoor control field,the effects of the Direct Linear Transformation and the Space Resection with multi-images to calibrate the digital camera internal parameters were analyzed and compared.The experiment results show that the calibration effect of the latter is better.Accordingly,combined with the total station measurement data,the accuracy of calculating the coordinates of spatial points by the Space Resection&Forward Intersection with multi-images and the Self-calibration Bundle Adjustment was analyzed and compared.The results show that both methods can achieve millimeter level accuracy with little difference.Among them,the spatial point RMSE(Root Mean Square Error)calculated by the Selfcalibration Bundle Adjustment is 1.8 mm,and its solving accuracy is 37.9%higher than that of the Space Resection&Forward Intersection with multi-images.However,the Self-calibration Bundle Adjustment has some problems such as long calculation time and difficult convergence etc.Therefore,it is determined that the Space Resection&Forward Intersection with multi-images is more suitable for the service slope surface deformation monitoring.2)Based on the positioning technology of line feature and circle feature,the deformation monitoring target schemes of triangle plate and square plate were designed respectively.The comparison experiment results show that the triangle plate scheme of line feature has the spatial point RMSE of 5.6 mm.While the square plate scheme of circle feature has the spatial point RMSE of 5.0 mm,which is reduce by 10.7%compared with the former,and has high area utilization rate.Therefore,the square plate scheme of circle feature has a better positioning effect of the monitoring point,and the recognition and positioning algorithms are simple and efficient,which is easy to process and manufacture,so as to optimize and choose the square plate scheme of circle feature.3)According to the above research results and the related theories and algorithms of Digital Close-range Photogrammetry,the slope surface deformation monitoring system based on Digital Close-range Photogrammetry was developed by using C#and OpenCV,and the actual slope was monitored and verified by UAV.The monitoring results show that the monitoring method of UAV Digital Close-range Photogrammetry technology cooperated with the deformation monitoring target can achieve millimeter level monitoring accuracy.The point RMSE of horizontal displacement monitoring is 3.5 mm,and the elevation RMSE of vertical displacement monitoring is 1.6 mm,which meet the accuracy requirements of national standard for landslide monitoring.At the same time,the production of deformation monitoring target is reliable and inexpensive.Based on this,a technology scheme of service slope surface deformation monitoring was summarized and proposed.In summary,a service slope surface deformation monitoring technology based on UAV Digital Close-range Photogrammetry was researched and obtained in this thesis,which can be applied to the high slope deformation monitoring in operating mountainous expressway.