Design And Implementation Of AIS Network System Based On MQTT Protocol

AIS(Automatic Identification System)is a shipborne broadcast response system through which ships can continuously transmit to nearby ships and shore authorities on the VHF(Very High Frequency)very common radio channel Its identity,location,course,speed and other data.AIS information is one of the main channel elements of the Yangtze River Waterway Bureau for channel operation and maintenance and service to social ships.Currently,obtaining AIS information can be collected through third-party data exchange or by deploying AIS receivers in the waterway.The third-party data exchange will lead to a slow update cycle of AIS information,which is not suitable for real-time channel service work.At the same time,the AIS receiving device receives a limited range of AIS and cannot cover the entire river.Therefore,it is necessary to research and design a system that can fully cover and receive the target channel,ensure that the staff can grasp the traffic situation of the ship in the channel in real time,improve the work efficiency of the channel management department,and ensure the safety of the channel.Taking the Chongqing section of the Yangtze River Channel as the research background,the thesis aims to effectively obtain real-time AIS information of ships in the channel at present.By establishing an AIS network system covering the entire river section to obtain real-time ship information of the target channel,it can enhance the grasp of the ship’s real-time navigation status Improve the level of channel operation and maintenance.The main content of the thesis is as follows:(1)Describe the current channel background and existing problems,analyze the detailed requirements for the construction of the AIS network system,and formulate relevant technical routes for the system;for the current inability to implement full coverage monitoring of the Chongqing section of the channel,analyze the conditions required to build the system and Combined with the actual situation,design and build the overall architecture of the AIS network system.(2)Regarding the problems of high hardware cost and difficult installation of commercial AIS receivers,research and design embedded AIS receivers to ensure the reliability of collecting AIS;for how to ensure reliable and fast data transmission,the MQTT protocol is selected by comparing and analyzing the characteristics between the protocols As the communication protocol of the system,it provides a basis for access to the mobile terminal and enhances the scalability of the system.(3)Aiming at the data conflict and redundancy caused by multiple AIS acquisition terminals,a cache-based AIS deduplication fusion algorithm and a dictionary sequence-based deduplication fusion algorithm are proposed,and after field test comparison,a dictionary sequence-based deduplication fusion is selected As a solution to the problem of data redundancy;for the problem of how to display ships in real time,the AIS real-time display system was designed and built.Finally,the system has been deployed at various test points in the Chongqing section of the Yangtze River Channel,and the system can operate stably for a long time.After field testing,the research work in this thesis can accurately display the ship information in real time,which is convenient for the channel department to understand the real-time channel information..