Research On Crack Detection Technology Of Highway Subgrade Slope Based On Lidar

The detection of highway subgrade slope cracks is of great significance to ensure the safety of highway transportation,and can lay the foundation for a series of highway subgrade slope disaster prevention projects such as accurate identification and precise maintenance.In order to realize the evaluation of the crack detection effect of the highway subgrade slope and provide data support for the crack detection work,it is necessary to measure the surface topography of the highway subgrade slope.However,traditional measurement methods have disadvantages such as single detection method,high installation cost,long detection cycle,and low manual operation safety.With the rapid development of computer,optics,electronic devices and other related fields,the research of measurement technology based on lidar has become a current research hotspot.The use of lidar technology in the detection of cracks on highway subgrade slopes can greatly increase the measurement speed,which is of great significance to improve the efficiency of highway subgrade slope crack detection.Therefore,the focus of this paper is to quickly and accurately obtain the surface data of the highway subgrade slope,generate a three-dimensional topographic map of the subgrade slope based on the measured data,and identify and quantify the cracks.The paper analyzes the current related technologies for monitoring the stability of highway subgrade slopes,as well as the research status and main application fields of lidar measurement technology in domestic and foreign literature,and applies the current detection methods to the detection of highway subgrade slope cracks.In the process,the measurement data of the roadbed slope surface cannot be obtained quickly and accurately.This paper studies and designs the hardware equipment for obtaining the measurement data of the vehicle-mounted lidar,and uses the calibration test to calibrate the lidar.In terms of data processing,the dissertation studies the pattern of missing data during the experiment,and uses linear interpolation for data interpolation.At the same time,it studies the filtering method suitable for the detection of highway subgrade slope cracks,and filters the mean value through filtering experiments.The filtering effect of four filtering methods,median filtering,five-point third filtering and low-pass filtering are compared and analyzed,and it is found that low-pass filtering has the best effect.The thesis designed and developed the three-dimensional visualization,crack identification and quantification algorithm of the roadbed slope crack measurement data of the vehicle-mounted Lidar,and realized the complete process from data collection to the generation of three-dimensional topographic maps to crack detection and quantification.It has certain practical and reference significance in the detection of roadbed slope cracks.