Research On Multi-source Information Fusion Technology Based On Large-scale Offshore Ship Positioning System

Under the guidance of economic globalization,the development of shipping industry is particularly fast,and the number of ships is also increasing year by year.This makes the navigation environment complicated and shipping traffic management difficult.For this reason,the International Maritime Organization has produced a series of rules and treaties to manage maritime traffic.Even so,maritime accidents occur frequently,which not only causes loss of human and material resources,but also causes serious pollution to the navigation environment.At present,the information obtained by a single navigation device is difficult to satisfy the needs of modern marine transportation industry,so this thesis make further research on the method of radar and automatic identification system AIS information fusion.In order to improve the positioning accuracy,get a more comprehensive,reliable,timely shipping information,this thesis focus on the radar and AIS characteristics,make use of the complementary of the two information,combined with the basic theory of information fusion and the structure model,key research track correlation and point track combination algorithm,and complete the design of each functional module of offshore ship positioning system.The main research work of this thesis is as follows :（1）analyze the feasibility of radar and AIS target information and build a radar and AIS distributed fusion system model.（2）Study the fuzzy theory algorithm and construct a track correlation algorithm based on multi-attribute set fuzzy theory.According to the comprehensive correlation membership degree of radar and AIS target track at the same time,the related track with the highest similarity is searched.（3）The weighted covariance fusion algorithm in data fusion is adopted to solve the problem of radar and AIS point track combination.The weighted weight is calculated according to the minimum mean square error criterion,and the target fusion track is obtained by the extended Kalman filter.（4）Simulation analysis of radar and AIS target information fusion.The system data are generated by simulation of large-scale ship positioning system.After the data are aligned to the same time,the target track with high correlation degree is selected for fusion.（5）Design software functional modules based on software requirements,and test functional integrity and feasibility through fusion examples.By comparing the four target factors before and after the track fusion,the range,bearing,speed and heading data after the fusion are improved by 64.49%,51.64%,69.71% and31.86% compared with radar,and 29.98%,32.17%,29.21% and 21.38% compared with AIS.The simulation experiments show that the information fusion method in this thesis has practical significance to reduce the measurement error.