Design And Implementation Of BDS/GPS High-precision Positioning System For Continuous Compaction Of Roadbed

In view of the inaccurate lane positioning of the current subgrade continuous compaction system,the roller compaction pass is still manually counted,the terminal display device uses a customized system without cross-platform and the display device mostly relies on wired connection and so on.A kind of subgrade continuous compaction system using BDS/GPS with high precision positioning is designed.Firstly,the MW combination method and the pseudorange/carrier phase combination are studied and applied to the detection and repair of cycle slip and the determination of the ambiguity.Secondly,by studying a variety of differential correction algorithm and using the improved optimal triangle interpolation method for the virtual station differential correction generation work according to the characteristics of each algorithm.By studying several coordinate systems and the conversion methods between these coordinate systems,the complete conversion process from the receiver output coordinates to the construction site coordinates is given.Then,according to the characteristics of the road roller and the highprecision positioning result,a method of automatically calculating the rolling number of the roller is used.Then an in-depth study of hardware module design and integration,software workflow on different hardware devices,GPRS and Bluetooth transmission data process and running state transition process,designed a set of private data transmission protocol and produced a product that can be applied to practical operations.Then,in order to realize the cross-platform of the system terminal display,the Web Bluetooth API for supporting the browser Bluetooth function and the browser Web App supported by all mainstream platforms were developed to develop the terminal display program,and combined with the mainstream Web App design architecture,A web app that satisfies the basic functions.Finally,the indicators are measured by experiments,and the accuracy of the obtained positioning results is better than 0.05 m.The average starting time for the first differential positioning is 58 s,and the time availability accuracy index is 99.92%.