Study On Terrestrial Laser Scanning For The Pavement Roughness Inspection

The traditional road surface roughness detection method has large measurement error and low efficiency,and it has been difficult to meet the needs of modern society for road detection and road maintenance.Non-contact detection method of vehicular laser flatness detection method restricted by pavement construction,and its precision will be affected by the bumpy road,and it is susceptible to the influence of traffic incidents and termination,expensive,use USES a single,larger burden.The ground 3d laser scanning measurement data has the characteristics of high precision,high density and multi-information,and can describe the details of the road in detail.Therefore,this paper studies the pavement flatness detection using ground 3d laser scanning system.The research contents include:(1)Research point cloud data processing method,first of all,the point cloud preprocessing,including point cloud removal,point cloud sampling and point cloud splicing.Secondly,the least square method is used to make quadric surface fitting filtering for point cloud data,and the cloud data of the reservation surface point and the cloud data of near ground vegetation point.In the end,using the RANSAC algorithm to extract the pavement point cloud data.(2)Study on the influence factors of the calculation method of international flatness,namely the influence of initial value and statistical interval.This paper analyzes the different effects of three initial value assignment methods,namely,the initial value is "0",the initial value is "11m slope" and the initial value is continuous,and it is found that the continuous effect of the initial value can be completely eliminated.The effects of different statistical intervals 10 m,30m,50 m and 100 m on the calculation results were analyzed,and different statistical intervals were found to show different emphasis,which could be selected according to actual needs.(3)Study on the reliability of the ground-based 3d laser scanning system applied to pavement smoothness,namely,repeatability test and correlation test.Repeated experiments were performed in the exact same test position,test environment,test method and test equipment,and the variation coefficient was calculated to meet the requirements of 2.564% of the variation coefficient <5%.In this paper,precision electronic level is used as the standard test method to carry out correlation test,calculate the correlation coefficient and meet the requirement of correlation test.(4)Study on the influence of different factors on the surface roughness detection of the ground 3d laser scanning system.It is found that different longitudinal sections and different scanning densities have little effect on flatness detection.When the sampling interval was over 0.03 mm,the IRI calculated result deviation was more than 1%.Noise has a great influence on the calculation of pavement international flatness index.(5)Select a section of the Chinese mining university with a length of about 1200 m as an example to study the surface roughness detection of 3d laser scanning system on the ground.According to the scanning characteristics of the road section and the ground 3d laser scanner,the scanning scheme is set up to calculate the international flatness index of the road section.