Research On Pavement Roughness Index Based On Spatial Surface Feature

As the total mileage of highway maintenance in China accounts for more and more proportion in the road network,the detection and evaluation of pavement conditions as its basis become particularly important.In the evaluation of pavement roughness,the lack of precision of the testing equipment and the singular evaluation of indicators will lead to incomplete evaluation of pavement roughness during driving.Based on this,the main research content and results of this article are as follows:First of all,to solve the problem of insufficient accuracy of the commonly used pavement three-dimensional measurement equipment,a ground three-dimensional laser scanning system is introduced,and the road surface is scanned and measured using the Trimble TX8 laser three-dimensional scanner.Using Trimble Real Works and Geomagic Studio two point cloud processing software,the scanned original point cloud is preprocessed such as point cloud registration,point cloud segmentation,point cloud denoising and point cloud reduction,to obtain accurate three-dimensional points on the pavement surface Cloud data.Secondly,the digital surface reconstruction of pavement 3D point cloud data is completed.Through the pavement point cloud encapsulation,the pavement irregular triangle network model is obtained,and the holes in the model are detected and filled.Then through free surface fitting and gridding operation,the pavement NURBS digital surface model is obtained.In addition,the errors in each stage from measurement to surface reconstruction are analyzed and calculated to determine the total error in the whole process.Then,the parameter equation of the pavement spatial surface was fitted.Using the method of fitting the datum plane,the pre-processed pavement 3D point cloud data was de-curved and de-graded.Then,performing surface fitting on the three-dimensional point cloud data of the pavement,the pavement spatial surface parameter equation with good fitting effect is obtained,and the reliability analysis is carried out using the existing pavement detection data.Finally,the evaluation index of pavement spatial roughness is established.Aiming at the problem of insufficient evaluation of the commonly used IRI indicators,a 7-degreeof-freedom vehicle-pavement model based on the entire vehicle is established,and the vibration equation of the model is analyzed and solved,and the digital elevation model and the parametric equation model of the surface are considered respectively Vertical excitation of the tire.Finally,considering the bump,roll and pitch responses during driving,the spatial surface roughness index SSRI is proposed and compared with the existing pavement roughness index to clarify the advantages of its application.