Design And Implementation Of Location And Orientation System Based On Differential GPS

As an advanced measurement method,differential GPS positioning and orientation system can not only provide position information,but also can provide directional information.The design of a fast,high precision differential GPS positioning and orientation system plays an important supporting role in improving the navigation,directional measuring posture and engineering deformation monitoring accuracy.Firstly,the general development and research status of GPS positioning and orientation were studied in-depth understanding of principle,method,and GPS positioning error sources,which provides theory basis for the design of the system.Secondly,this paper system atically analyzed the function and uses the unified modeling language(UML)to analyze and designed the the overall framework from the system use cases and data flow.Through the serial port communication technique,the problem of the data communication between the system software and the hardware of GPS is resolved.The system of positioning and measurement data acquisition and processing speed is improved using multi thread and interrupt callback technology,besides the position and orientation measurement time is reduced.Thirdly,the study of GPS data smoothing and abnormal data processing method forms a stable and reliable methods of GPS data processing.Coordinate systems are defined which are used in positioning and orientation,and gives the conversion relation between the coordinate systems is given;the orientation calculation model is deduced.Finally,from the point of view of system designers,the design and implementa tion methods of the system module,data interface and user interface are analyzed and designed,then the system software development is realized.Through the positioning and orientation test,the difference on the system points location measurement and orientation in the data are analyzed to show that,the design and implementation of differential GPS positioning and orientation system provides correct result of positioning and orientation,besides function and performance meet the design requirements.