Research And Development On The System Of High Accuracy Positioning Dredging Vessels Based On GPS

This thesis centers on the special topic of design and development on the GPSpositioning of channel dredging. Based on industrial computer, the system includesthe functions of real-time GPS data gathering, coordinate transformation, electronicchart displaying etc. It can be widely applied to dredging projects in order to improvethe positioning accuracy and the automation degree of dredging vessels.Traditional positioning methods of channel dredging can't meet the demand ofhigh accuracy. While GPS can improve these, in this paper we put this technologyinto the positioning of channel dredging.Firstly, this thesis introduces the main principle and the coordinate system ofGPS, depended on these theories, the mathematical models of differential GPS arefounded, and the relative merits of DGPS are analyzed, then we choose the RTK GPSmethod to position the dredging vessels, at last the quality of dredging positioning isdiscussed.Secondly, the positioning data received from GPS receiver are in coordinate ofWGS-84, while the results of dredging positioning are in local coordinate, so thecoordinate transformation is needed, in this paper the transformation mathematicalmodels of different steps are established.Thirdly, based on the Windows 2000 platform and the VC++ development tool,the dredging system software is developed, which concludes the functions of real-timedata acquisition, display of electronic chart, communication of GPS receiver andindustrial computer, GPS coordinate transformation and display of various parametersof sensors models etc. The automation degree of channel dredging can be deeplyimproved by using this software.Lastly, to validate the theoretical analysis, the experiments on the systemsoftware and the whole system were made. The results showed that the positioningaccuracy is deeply improved, it can meet the demand of dredging projects, this systemcan be widely applied in fields of channel dredging.