The Algorithm For Obtaining Lateral Distribution Of Wheel Tracks In "Dual Laser Measuring System"

Lateral distribution of wheel tracks can objectively describe the lateral distribution of the wheel track vehicles on the road,and the distribution on the structural mechanics analysis is of great significance to the study of the characteristics of roadbed is van damage must study truck tires when driving on the road cross section distribution characteristics,the characteristics of transverse distribution of the wheel track.For the acquisition of lateral distribution features of wheel tracks,the current main method is photography and video recording.In this method,the placement of photographic equipment on the roadside not only interferes with the normal driving of drivers,thus affecting the objectivity of measurement data,but also affects road traffic safety."Double laser measurement system" is a new kind of invention patent,this topic group "double laser measurement system" as a kind of brand-new,all-weather unattended,can automatically identify measurement system of transverse distribution of the wheel track of the vehicle,not only create the condition for vehicles and wheel recognition,also meet the scientific research and social production and construction requirements for efficiency,accuracy and safety."Wheel track lateral distribution characteristic measurement system" is an important part of "double laser measurement system" which needs to be further developed.The research object of this project is the algorithm to obtain the transverse distribution of wheel tracks in the "measurement system of lateral distribution characteristics of wheel tracks",namely,the process of "double laser measurement system" from the initial data collection to the final acquisition of lateral distribution characteristics of wheel tracks.The algorithm steps include: 1.Collection of original data;2.Select "cars" from the original data,that is,restore the vehicle data;3.Calculate the speed;4.Create "feature tire" database;5.Modify vehicle data;6.Identify "feature points" of "feature tires" of heavy trucks by comparing the similarity between "tires" and vehicles in the database of "feature tires".In the verification part of this paper,data were collected and tested in Zhanjiang city,Shenzhen city,Guangdong province,and Daye city,Hubei province for a period of one month.Firstly,the data collected from a section of Shenhai expressway in Zhanjiang city were tested to screen "cars",and the number of vehicles obtained was compared with the actual number.The error rate was: 11/1147 = 0.959%,and the error rate was less than 1%.The result was in line with expectations.For the stage of "calculating the speed",the speed value of 142 cars was screened out from the vehicle data on Yueliangwan avenue in Shenzhen city,and then unary linear analysis was conducted with the corresponding vehicle speed value measured by manual speed gun to obtain the formula: y = 1.0023 x-0.0821,R~2 = 0.9997.Similarity R~2 = 0.9997,indicating strong correlation between the two groups of data;The coefficient value of 1.0023 also indicates that the velocity values obtained by the two methods have a strong correlation,indicating the high accuracy of the results.The establishment of "characteristic tire" database is through the method of manual identification.1000 tires with "concave and convex" are selected from the data of heavy trucks and put into the database.For identification of a "feature points",the test sample is still Shenzhen its crescent avenue of data and the sifting 544 trucks,will be based on the "double laser measurement system" get "feature points" as the independent variable X,based on visual photography video method to read " feature points " as the independent variable Y,monadic linear regression analysis,get the formula of Y = 0.9998 * X,R~2 = 0.9918.Where,similarity R~2=0.9918 means that the two groups of data are strongly correlated,and the coefficient value of independent variable X = 0.9998 means that the results obtained by the two methods are highly correlated.The comparison results of the above two groups of "feature points" indicate that the lateral distribution features of road tracks obtained by the "dual laser measurement system" are also highly accurate.To sum up,"double laser measurement system",as a new measuring system of wheel track lateral distribution,can automatically identify the speed of vehicles and automatic vehicle classification,and the results obtained by the system are basically consistent with the results obtained by the traditional method of "photography and video recording".The "system" avoids the disadvantages of the traditional method,and the data acquisition process is stable and reliable.