A shipborne Beidou LRIT terminal for ship remote identification and tracking based on Beidou RDSS system

Abstract

The invention discloses a ship-borne Beidou LRI T terminal for remote identification and tracking of ships based on the Beidou RDSS system. The Beidou LRI T terminal interacts with an LRI T data center for data. The Beidou LRI T terminal includes an antenna unit, an inertial navigation unit, a Beidou RDSS / GNSS unit, a terminal control unit, and an LRI T business logic unit. The LRI T business logic unit includes an LRI T position reporting state management module, an LRI T request receiving and processing module, an LRI T information sending management module, and a user card management module. The advantages are: using Beidou global short message and positioning report service, solving the problems existing in the existing LRI T terminal based on the maritime satellite communication system: abnormal terminal position reporting, abnormal ghost ship, complex remote configuration, redundant position reporting caused by DN ID, etc., realizing the normal identification and monitoring of IMO convention ships by the LRI T data center, further improving the quality of ship position reporting, and better meeting the relevant requirements of the SOLAS convention.

Description

Technical Field

[0001] The present invention relates to the field of ship communication and navigation technology, and in particular to a ship-borne Beidou LRIT terminal for remote identification and tracking of ships based on a Beidou RDSS system. Background Art

[0002] In order to strengthen maritime security, protect the marine environment, organize distress search and rescue, and enhance maritime perception capabilities, the International Maritime Organization (International Maritime Organization) passed the International Convention for Safety of Life at Sea (SOLAS Convention) in 2006 to establish an amendment to the Long Range Identification and Tracking of Ships. According to the requirements of the amendment, passenger ships engaged in international voyages, cargo ships of 300 gross tons and above, and mobile offshore drilling units under the Contracting States must be equipped with communication and navigation equipment that meets the LRIT technical requirements to enable the Contracting States to remotely identify and track ships; at the same time, each Contracting State needs to establish a LRIT national data center to achieve remote dynamic tracking of its convention ships through satellite communication service providers and application service providers, and at the same time, it is necessary to process various requests from other national centers such as coastal states, port states, distress search and rescue, etc. through the International Data Exchange Center in accordance with the International Data Distribution Plan. The International Data Distribution Plan and the International Data Exchange Center are constructed and managed by the International Maritime Organization. The overall architecture of the LRIT system is as follows: Figure 1 shown.

[0003] In order to effectively implement the LRIT system construction, the International Maritime Organization has issued a series of resolutions, circulars and other documents after the passage of the SOLAS amendment on the LRIT system, establishing detailed technical specifications and technical requirements for system components such as shipborne LRIT equipment, national data centers, international data exchange centers, and international data distribution plans.

[0004] As a contracting member of the International Maritime Organization, my country has a legal obligation to develop the LRIT system in accordance with the relevant requirements of the SOLAS Convention Amendment, manage the dynamic position of its convention ships as a flag state, and process LRIT requests and respond to LRIT information in accordance with data user rules such as coastal states, port states, and distress search and rescue.

[0005] According to the requirements of the SOLAS LRIT Convention, the following three types of ships engaged in international navigation must install shipboard terminals that meet the LRIT technical requirements: passenger ships, including high-speed passenger ships; cargo ships of 300 gross tonnage and above, including high-speed cargo ships; mobile offshore drilling platforms. The technical and functional requirements that shipboard LRIT terminals should meet include: the terminal should be a shipboard communication device with a built-in or external global navigation positioning receiver; the communication system used by the terminal should provide coverage support for all ocean areas where the ship is sailing; the terminal can automatically report LRIT information to the LRIT data center at intervals of 6 hours; the LRIT information reported by the terminal includes: ship identification, ship positioning, and positioning time; the terminal supports the LRIT data center to remotely configure the terminal's LRIT information reporting interval; the terminal supports a single paging POLL command, that is, it can respond to the data center's single call for ship position instructions.

[0006] According to relevant technical specifications, shipborne terminals must pass the LRIT shipborne equipment conformity test organized by the application service provider authorized by the flag state and obtain the corresponding conformity test report before they can officially join the ship remote identification and tracking system of the flag state data center. The main test contents and test standards of LRIT shipborne equipment conformity test are shown in the following table:

[0007]

[0008]

[0009] The BeiDou Navigation Satellite System is a global satellite navigation system independently built and operated by my country with a view to national security and economic and social development needs. It is an important national space-time infrastructure that provides all-weather, all-day, high-precision positioning, navigation and timing services to global users. In July 2020, the BeiDou-3 global satellite navigation system completed the global constellation deployment and opened the full system service. On the basis of providing traditional satellite radio navigation (RNSS, Radio Navigation Satellite Service) services, it also provides satellite radio determination (RDSS, Radio Determination Satellite Service) services. Through the innovative integration of navigation and communication capabilities, it provides positioning, navigation and timing (RNSS), global short message communication (GSMC) and international search and rescue (SAR) services worldwide; in addition, it provides satellite-based augmentation (SBAS), ground-based augmentation (GAS), precise point positioning (PPP) and regional short message communication (RSMC) services for China and surrounding areas.

[0010] The application of Beidou RDSS services can provide active positioning, position reporting and short message communication functions for user terminals. At present, the ship-borne terminals of the ship remote identification and tracking system mainly use the GPS system as the source of global navigation and positioning data, and use Inmarsat maritime satellites or Iridium satellites as global satellite communication means. The main problems include:

[0011] 1. Shipborne equipment stops reporting LRIT information abnormally, causing the ship to be stranded in foreign ports and unable to pass flag state radio inspections. Under normal circumstances, shipborne equipment should report LRIT information (identification, time, longitude and latitude) to the LRIT data center at intervals of 6 hours. However, due to the communication mechanism of the Inmarsat maritime satellite system, in the event of navigation area switching, concurrent message communication, and LRIT terminals serving as GMDSS or SSAS functions, the shipborne equipment may fail to send data reports, DNID configuration information may be lost, and PROGRAM configuration may fail, causing the shipborne equipment to be unable to report LRIT information normally, affecting the normal operation and management of the ship.

[0012] 2. Problems with abnormal reporting of positions and settlement of communication fees of ghost ships. Under special circumstances, the ship operator did not notify the LRIT data center in advance, but directly handled the cancellation business through the shipboard satellite communication equipment access agency, resulting in the DNID, PROGRAM and other resources stored in the equipment not being recovered in time, and ultimately causing the equipment to continue reporting its position, but the data center was unable to remotely shut down the reporting of the cancelled equipment. This is the ghost ship problem. The ghost ship problem will directly lead to a waste of communication resources and communication fees, interfere with the remote supervision of international ships, and affect the normal operation and management of the LRIT data center;

[0013] 3. The LRIT data center's remote configuration of the shipborne equipment's reporting interval instructions is complex and prone to failure. According to the technical requirements of the LRIT shipborne terminal, the data center should be able to remotely modify the terminal's reporting interval. At present, the maritime satellite communication system mainly relies on the remote POLLING instructions from the shore to the ship to realize the remote parameter configuration from the data center to the ship. The main POLLING instructions and main processes involved in remotely modifying the reporting interval include: determining the OCEANREGION (Atlantic-WEST, Atlantic-EAST, Pacific, Indian) where the terminal is logged in; sending the POLLING instruction of downloading DNID to the current ocean area; sending the POLLING instruction of PROGRAM-DNID to the current ocean area; sending the POLLING instruction of INITIATE-DNID to the current ocean area. The interactive process is too complicated and prone to failure.

[0014] 4. The mechanism of mapping maritime satellite terminal numbers with DNID combined with MEM NUMBER is prone to cause the problem of redundant position reporting. The POLLING and DATA REPORTING services of the maritime satellite communication system implement a management mechanism of mapping DNID combined with MEMNUMBER to terminal numbers. Under this mechanism, it is easy to set timed position reports for two groups of DNIDs at the same time, resulting in the problem of redundant position reporting. Summary of the invention

[0015] The object of the present invention is to provide a ship-borne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system, thereby solving the above-mentioned problems existing in the prior art.

[0016] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0017] A ship-borne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system, wherein the Beidou LRIT terminal interacts with the LRIT data center; the Beidou LRIT terminal comprises:

[0018] Antenna unit; used to receive GNSS signals and send and receive Beidou RDSS information;

[0019] Inertial navigation unit; used to calculate navigation information by fusing GNSS information and using the Kalman filter algorithm to ensure that LRIT positioning information is provided normally when GNSS signals cannot be received normally;

[0020] Beidou RDSS / GNSS unit; used to analyze the received GNSS signals and output the ship's positioning, time, heading and speed information; used to implement RDSS services, supporting the functions of sending Beidou short messages, receiving short messages and position reporting;

[0021] Terminal control unit; used to provide logic control, data calculation, data storage, data interaction and power supply functions for the Beidou LRIT terminal;

[0022] LRIT business logic unit; including

[0023] LRIT reporting status management module: used to manage the reporting status of Beidou LRIT terminals; supports the LRIT data center to remotely modify the relevant parameters of the reporting status of Beidou LRIT terminals, supports the LRIT information sending management module to read the reporting status of Beidou LRIT terminals, and report the position according to the relevant parameters;

[0024] LRIT request receiving and processing module; used for receiving and processing LRIT requests and instructions from the LRIT data center;

[0025] LRIT information sending management module; used for LRIT information encapsulation, link selection, information sending, confirmation and retransmission, and supports the use of symmetric encryption algorithm to encrypt and transmit LRIT information, and supports the use of data compression algorithm to compress LRIT information;

[0026] User card management module: used to manage LRIT services for Beidou IC users.

[0027] Preferably, the reporting status of the Beidou LRIT terminal includes a scheduled position reporting status, a start reporting time, and a reporting interval; the scheduled position reporting status includes an initial state, an on state, and a off state; the start reporting time is a time expressed in UTC time and in UNIX TIMESTAPM format; the reporting interval is an interval parameter in seconds.

[0028] Preferably, under the initial conditions, after receiving a request to start the timed position report, the start position reporting time and the position reporting interval parameters are extracted from the request, and the LRIT position reporting state management module sets the timed position report to the on state, and sets the corresponding start position reporting time and the position reporting interval parameters according to the start position reporting time and the position reporting interval parameters extracted from the request;

[0029] Under the initial conditions, after receiving the request to turn off the scheduled position report, the LRIT reporting status management module sets the scheduled position report to the off state and resets the start reporting time and reporting interval parameters to the initial state;

[0030] When the Beidou LRIT terminal is in the timed position reporting on state, upon receiving a request to set a timed position reporting, the LRIT position reporting status management module updates the start position reporting time and the position reporting interval; upon receiving a request to stop the position reporting, the LRIT position reporting status management module sets the timed position reporting state to off, and sets the start position reporting time and the position reporting interval to the initial state.

[0031] Preferably, the Beidou LRIT terminal calls the receiveMessage interface of the LRIT request receiving and processing module to receive the LRIT request; and according to different request types, calls the processStartRequest interface to process the start location report request, calls the processStopRequest interface to process the stop location report request, and calls the processPollRequest interface to process the paging location request; the LRIT request is encapsulated in the form of a Beidou RDSS message, and the request instruction includes the sender number, receiving time, request type, request content, and request ID.

[0032] Preferably, the processing flow of the start position report request is to extract the start position reporting time and position reporting interval parameters from the request message, call the terminal position reporting management module setProgrammedStatus interface to set the scheduled position reporting status to on, call the terminal position reporting management module setProgrammedStartTime interface to set the start position reporting time, call the terminal position reporting management module setProgrammedInterval interface to set the position reporting interval, and call the sendACK interface of the LRIT information management module to reply receipt information to the data center;

[0033] The processing flow of the stop position report request is as follows: after receiving the stop position report request, the terminal position reporting management module setProgrammedStatus interface is called to set the scheduled position reporting status to off, the terminal position reporting management module setProgrammedStartTime and setProgrammedInterval interfaces are called to set the start position reporting time and position reporting interval parameters to the initial state, and the LRIT information sending management module sendACK interface is called to reply the receipt information to the data center;

[0034] The processing flow of the paging location request is as follows: after receiving the paging location request, the makeReport interface of the LRIT information management module is called to generate the response LRIT information, and the sendReport interface is called to send the LRIT information.

[0035] Preferably, the instructions that the LRIT request receiving and processing module can parse include a single call location instruction, a 15-minute timed report setting instruction, a 30-minute timed report setting instruction, a 60-minute timed report setting instruction, a 3-hour timed report setting instruction, a 6-hour timed report setting instruction, a 12-hour timed report setting instruction, a 24-hour timed report setting instruction, and a timed report off instruction.

[0036] Preferably, after receiving the single call location instruction, the LRIT request receiving and processing module returns a LRIT information to the LRIT data center through the LRIT information sending queue management module; after receiving the timing report instruction, the LRIT request receiving and processing module returns the LRIT information to the LRIT data center at a specified interval through the LRIT information sending queue management module; after receiving the closing timing report instruction, the LRIT request receiving and processing module stops the currently valid timing location report;

[0037] The LRIT information sending queue management module returns confirmation information to the LRIT data center in the form of user ack confirmation combined with exponential backoff for the instructions received by the LRIT request receiving and processing module, and receives a secondary confirmation message from the LRIT data center. If the secondary confirmation message is not received, it automatically resends the message.

[0038] Preferably, when the Beidou LRIT terminal triggers the information sending function of the LRIT information sending management module due to a single call request or a timed position report from the LRIT data center, the LRIT information is first obtained through the Beidou GNSS / RDSS unit, and after the information is successfully obtained and packaged, it is sent to the LRIT data center through the RDSS short message link;

[0039] If the Beidou GNSS / RDSS unit fails to obtain LRIT information, the Beidou LRIT terminal will obtain and encapsulate the LRIT information through the inertial navigation unit and then send it to the LRIT data center through the RDSS short message link;

[0040] If the inertial navigation unit cannot obtain LRIT information, it will try the RDSS position reporting service and send the information to the LRIT data center.

[0041] Preferably, the LRIT information sending management module includes a makeReport interface for generating and encapsulating LRIT information, a sendReport interface for sending LRIT information, and a sendACK interface for sending ACK receipt information;

[0042] The makeReport interface generates LRIT information based on the Beidou RDSS / GNSS unit and the inertial navigation unit and encapsulates it in a format;

[0043] The sendReport interface calls the Beidou RDSS / GNSS unit’s position report and the short message sending interface sends LRIT information to the LRIT data center;

[0044] The sendACK interface calls the short message sending interface of the Beidou RDSS / GNSS unit to send the start position report receipt and stop position report receipt information to the LRIT data center;

[0045] In order to ensure the quality of LRIT information collected by the LRIT data center, the LRIT information sending management module adopts three-way handshake and exponential backoff to send LRIT information.

[0046] Preferably, the user card management module performs LRIT service management on Beidou IC users including authority management, Beidou service type management, and communication frequency management.

[0047] The beneficial effects of the present invention are as follows: using Beidou global short message and positioning reporting services, the problems existing in the existing LRIT terminals based on the maritime satellite communication system, such as abnormal terminal position reporting, abnormal ghost ship, complex remote configuration, and redundant position reporting caused by DNID, are solved, and the LRIT data center can normally identify and monitor IMO convention ships, further improve the quality of ship position reporting, and better meet the relevant requirements of the SOLAS convention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structure of the LRIT system in the prior art;

[0049] Figure 2 is a schematic diagram of data interaction between a Beidou LRIT terminal and a LRIT data center in an embodiment of the present invention;

[0050] Figure 3 is a schematic diagram of the structure of a Beidou LRIT terminal in an embodiment of the present invention;

[0051] Figure 4 is a flow chart of LRIT reporting status management of a Beidou LRIT terminal in an embodiment of the present invention;

[0052] Figure 5 Schematic diagram of LRIT information transmission between a Beidou LRIT terminal and a LRIT data center in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] like Figure 2 and Figure 3 As shown, in this embodiment, a Beidou LRIT terminal for ship remote identification and tracking based on the Beidou RDSS system is provided, and the Beidou LRIT terminal interacts with the LRIT data center; the Beidou LRIT terminal includes five units; respectively as follows:

[0055] 1. Antenna unit: The hardware includes GNSS antenna and RDSS antenna; it is used to receive GNSS signals and send and receive Beidou RDSS information.

[0056] 2. Inertial navigation unit; the hardware includes a three-axis gyroscope and a three-axis accelerometer; it is used to calculate navigation information by fusing GNSS information and using the Kalman filter algorithm to ensure that LRIT positioning information is provided normally when the GNSS signal cannot be received normally.

[0057] 3. Beidou RDSS / GNSS unit; the hardware includes GNSS receiving module, Beidou RDSS communication module and Beidou smart card; the GNSS receiving module is responsible for parsing the received GNSS signals and outputting the ship's positioning, time, heading and speed information; the Beidou RDSS communication module is used to implement RDSS services and supports the functions of sending Beidou short messages, receiving short messages and position reporting.

[0058] 4. Terminal control unit; the hardware includes processor, memory, data interface, and power supply; it is used to provide logic control, data calculation, data storage, data interaction, and power supply functions for the Beidou LRIT terminal.

[0059] 5. LRIT business logic unit; including

[0060] (1) LRIT reporting status management module: used to manage the reporting status of the Beidou LRIT terminal; supports the LRIT data center to remotely modify the relevant parameters of the Beidou LRIT terminal's reporting status, supports the LRIT information sending management module to read the reporting status of the Beidou LRIT terminal, and reports the position according to the relevant parameters.

[0061] In this embodiment, the reporting status of the Beidou LRIT terminal includes a scheduled position reporting status, a start reporting time, and a reporting interval; the scheduled position reporting status includes an initial state, an open state, and a closed state; the start reporting time is a time expressed in UTC time and in UNIX TIMESTAPM format; the reporting interval is an interval parameter in seconds.

[0062] like Figure 4 As shown, in this embodiment, under the initial conditions, after receiving a request to start the regular position report, the start position reporting time and the position reporting interval parameters are extracted from the request, and the LRIT position reporting state management module sets the regular position report to the on state, and sets the corresponding start position reporting time and the position reporting interval parameters according to the start position reporting time and the position reporting interval parameters extracted from the request;

[0063] Under the initial conditions, after receiving the request to turn off the scheduled position report, the LRIT reporting status management module sets the scheduled position report to the off state and resets the start reporting time and reporting interval parameters to the initial state;

[0064] When the Beidou LRIT terminal is in the timed position reporting on state, upon receiving a request to set a timed position reporting, the LRIT position reporting status management module updates the start position reporting time and position reporting interval parameters; upon receiving a stop position reporting request, the LRIT position reporting status management module sets the timed position reporting state to off, and sets the start position reporting time and position reporting interval parameters to the initial state.

[0065] (2) LRIT request receiving and processing module: used to receive and process LRIT requests and instructions from the LRIT data center.

[0066] In this embodiment, the Beidou LRIT terminal calls the receiveMessage interface of the LRIT request receiving and processing module to receive the LRIT request; and according to different request types, calls the processStartRequest interface to process the start location report request, calls the processStopRequest interface to process the stop location report request, and calls the processPollRequest interface to process the paging location request; the LRIT request is encapsulated in the form of a Beidou RDSS message, and the request instruction includes the sender number, receiving time, request type, request content, and request ID.

[0067] In this embodiment, the processing flow of the start position report request is to extract the start position reporting time and position reporting interval parameters from the request message, call the terminal position reporting management module setProgrammedStatus interface to set the scheduled position reporting status to on, call the terminal position reporting management module setProgrammedStartTime interface to set the start position reporting time, call the terminal position reporting management module setProgrammedInterval interface to set the position reporting interval, and call the sendACK interface of the LRIT information management module to reply the receipt information to the data center;

[0068] The processing flow of the stop position report request is as follows: after receiving the stop position report request, the terminal position reporting management module setProgrammedStatus interface is called to set the scheduled position reporting status to off, the terminal position reporting management module setProgrammedStartTime and setProgrammedInterval interfaces are called to set the start position reporting time and position reporting interval parameters to the initial state, and the LRIT information sending management module sendACK interface is called to reply the receipt information to the data center;

[0069] The processing flow of the paging location request is as follows: after receiving the paging location request, the makeReport interface of the LRIT information management module is called to generate the response LRIT information, and the sendReport interface is called to send the LRIT information.

[0070] The instructions that the LRIT request receiving and processing module can parse include: single call location instruction, set 15-minute timed report instruction, set 30-minute timed report instruction, set 60-minute timed report instruction, set 3-hour timed report instruction, set 6-hour timed report instruction, set 12-hour timed report instruction, set 24-hour timed report instruction, and close timed report instruction;

[0071] In this embodiment, after receiving the single call location instruction, the LRIT request receiving and processing module returns a LRIT information to the LRIT data center through the LRIT information sending queue management module; after receiving the timing report instruction, the LRIT request receiving and processing module returns the LRIT information to the LRIT data center at a specified interval through the LRIT information sending queue management module; after receiving the closing timing report instruction, the LRIT request receiving and processing module stops the currently valid timing location report;

[0072] The LRIT information sending queue management module returns confirmation information to the LRIT data center in the form of user ack confirmation combined with exponential backoff for the instructions received by the LRIT request receiving and processing module, and receives a secondary confirmation message from the LRIT data center. If the secondary confirmation message is not received, it automatically resends the message.

[0073] (3) LRIT information transmission management module: used for LRIT information encapsulation, link selection, information transmission, confirmation and retransmission, and supports the use of symmetric encryption algorithm to encrypt and transmit LRIT information, and supports the use of data compression algorithm to compress LRIT information.

[0074] In this embodiment, when the Beidou LRIT terminal triggers the information sending function of the LRIT information sending management module due to a single call request or a timed position report from the LRIT data center, the LRIT information is first obtained through the Beidou GNSS / RDSS unit, and after successfully obtaining and encapsulating the information, it is sent to the LRIT data center through the RDSS short message link;

[0075] If the Beidou GNSS / RDSS unit fails to obtain LRIT information, the Beidou LRIT terminal will obtain and encapsulate the LRIT information through the inertial navigation unit and then send it to the LRIT data center through the RDSS short message link;

[0076] If the inertial navigation unit cannot obtain LRIT information, it will try the RDSS position reporting service and send the information to the LRIT data center.

[0077] In this embodiment, the LRIT information sending management module includes a makeReport interface for generating and encapsulating LRIT information, a sendReport interface for sending LRIT information, and a sendACK interface for sending ACK receipt information; the makeReport interface generates LRIT information based on GNSS and inertial navigation data (Beidou RDSS / GNSS unit and inertial navigation unit) and performs format encapsulation; the sendReport interface calls the position report of the Beidou RDSS communication module (Beidou RDSS / GNSS unit) and the short message sending interface to send LRIT information to the LRIT data center; the sendACK interface calls the short message sending interface of the Beidou RDSS communication module (Beidou RDSS / GNSS unit) to send the start position report receipt and the stop position report receipt information to the LRIT data center;

[0078] In order to ensure the quality of LRIT information collected by the LRIT data center, the LRIT information sending management module adopts three-way handshake and exponential backoff to send LRIT information.

[0079] (4) User card management module: used to manage LRIT services for Beidou IC users.

[0080] The user card management module performs LRIT service management on Beidou IC users, including authority management, Beidou service type management, and communication frequency management.

[0081] In this embodiment, the Beidou LRIT terminal can receive the LRIT request sent by the LRIT data center in the form of a short message through the Beidou RDSS link, and process and respond according to the type and parameters of different requests; for the received LRIT request for remote modification of the reporting status, the Beidou LRIT terminal can extract parameters such as the reporting start time and the reporting interval, and manage the terminal reporting status; for the LRIT information to be sent, the user-ack, three-way handshake, exponential backoff and other algorithms are used to ensure timely and accurate delivery of the information;

[0082] The Beidou user card management module is used to manage the frequency, authority, and user usage of Beidou communication services. In order to solve the problem of abnormal position reporting caused by the inability to obtain positioning information in the current LRIT terminal, the Beidou LRIT terminal adopts a combined positioning and navigation method that integrates GNSS and inertial navigation to obtain positioning information. In addition, when reporting the position to the LRIT data center, the Beidou LRIT terminal gives priority to the Beidou RDSS short message link. If it fails to receive the receipt confirmation from the center, it will try the Beidou RDSS active positioning service and send the positioning information to the LRIT data center.

[0083] Beidou LRIT terminals are deployed and installed on IMO Convention ships as shipborne equipment in accordance with IMO's functional and technical requirements for shipborne terminals and LRIT compliance test technical requirements. By integrating and applying Beidou RDSS communication services, the LRIT data center can realize remote identification and tracking of Convention ships.

[0084] The present invention makes targeted use of the technical characteristics of Beidou communication, such as high efficiency, high success rate, low cost, and easy maintenance, and effectively solves the outstanding problems of the current ship remote identification and tracking equipment based on Inmarsat maritime satellite and other technologies, which are specifically reflected in the following aspects: 1. In terms of improving communication efficiency, the ship remote identification and monitoring equipment based on maritime satellite and other technologies, because its communication mechanism itself is based on the L band 1.3-1.7GHz, has a relatively low communication rate, resulting in a long delay from sending instructions from the LRIT data center to obtaining the ship-side response, and it is impossible to remotely monitor the ship dynamics in real time; the present invention can effectively improve the communication rate and monitoring efficiency by adopting Beidou RDSS technology. 2. In terms of communication success rate, due to system congestion and other problems, there is a relatively obvious request failure in the maritime satellite ship-borne terminal. The present invention can effectively improve the communication success rate by utilizing Beidou RDSS technology. 3. In terms of cost, the present invention has cost advantages over traditional maritime satellite ship-borne terminals in terms of equipment purchase and later communication costs. 4. In terms of ease of maintenance, due to the communication mechanism of Beidou RDSS itself, the LRIT data center can easily monitor and manage the terminal, which has great advantages over traditional maritime satellite terminals.

[0085] By adopting the above technical solution disclosed in the present invention, the following beneficial effects are obtained:

[0086] The present invention provides a ship-borne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system. The terminal utilizes the Beidou global short message and positioning report service to solve the problems existing in the existing LRIT terminals based on the maritime satellite communication system: abnormal terminal position reporting, abnormal ghost ship, complex remote configuration, redundant position reporting caused by DNID, etc., realizes the normal identification and monitoring of IMO convention ships by the LRIT data center, further improves the quality of ship position reporting, and better meets the relevant requirements of the SOLAS convention.

[0087] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. A ship-borne Beidou LRIT terminal for ship remote identification and tracking based on the Beidou RDSS system, wherein the Beidou LRIT terminal interacts with the LRIT data center; the characteristics are: The Beidou LRIT terminal comprises: Antenna unit; Used to receive GNSS signals and send and receive Beidou RDSS information; Inertial navigation unit; used to calculate navigation information using the Kalman filter algorithm to ensure that LRIT positioning information is provided normally when GNSS signals cannot be received normally; Beidou RDSS / GNSS unit; used to analyze the received GNSS signals and output the ship's positioning, time, heading and speed information; used to implement RDSS services, supporting the functions of sending Beidou short messages, receiving short messages and position reporting; Terminal control unit; Used to provide logic control, data calculation, data storage, data interaction and power supply functions for Beidou LRIT terminals; LRIT business logic unit; including LRIT reporting status management module: used to manage the reporting status of Beidou LRIT terminals; supports the LRIT data center to remotely modify the relevant parameters of the reporting status of Beidou LRIT terminals, supports the LRIT information sending management module to read the reporting status of Beidou LRIT terminals, and report the position according to the relevant parameters; LRIT request receiving and processing module; used for receiving and processing LRIT requests and instructions from the LRIT data center; LRIT information sending management module; Used for LRIT information encapsulation, link selection, information transmission, confirmation and retransmission, and supports the use of symmetric encryption algorithms to encrypt and transmit LRIT information, and supports the use of data compression algorithms to compress LRIT information; User card management module: used to manage LRIT services for Beidou IC users.

2. The shipborne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system according to claim 1, characterized in that: The reporting status of the Beidou LRIT terminal includes a timing position reporting status, a start reporting time, and a reporting interval; the timing position reporting status includes an initial state, an open state, and a closed state; the start reporting time is a time expressed in UTC time and in UNIX TIMESTAPM format; the reporting interval is an interval parameter in seconds.

3. The shipborne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system according to claim 2 is characterized in that: Under the initial conditions, after receiving the request to start the timed position report, the start position reporting time and the position reporting interval parameters are extracted from the request, and the LRIT position reporting state management module sets the timed position report to the on state, and sets the corresponding start position reporting time and position reporting interval parameters according to the start position reporting time and position reporting interval parameters extracted from the request; Under the initial conditions, after receiving the request to turn off the scheduled position report, the LRIT reporting status management module sets the scheduled position report to the off state and resets the start reporting time and reporting interval parameters to the initial state; When the Beidou LRIT terminal is in the timed position reporting on state, upon receiving a request to set a timed position reporting, the LRIT position reporting status management module updates the start position reporting time and the position reporting interval; upon receiving a request to stop the position reporting, the LRIT position reporting status management module sets the timed position reporting state to off, and sets the start position reporting time and the position reporting interval to the initial state.

4. The shipborne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system according to claim 1, characterized in that: The Beidou LRIT terminal calls the receiveMessage interface of the LRIT request receiving and processing module to receive the LRIT request; and according to different request types, calls the processStartRequest interface to process the start position report request, calls the processStopRequest interface to process the stop position report request, and calls the processPollRequest interface to process the paging position request; The LRIT request is encapsulated in the form of a Beidou RDSS message, and the LRIT request includes a sender number, a receiving time, a request type, a request content, and a request ID.

5. The shipborne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system according to claim 4 is characterized in that: The processing flow of the start position report request is as follows: extract the start reporting time and reporting interval parameters from the request message, call the terminal reporting management module setProgrammedStatus interface to set the scheduled position reporting status to on, call the terminal reporting management module setProgrammedStartTime interface to set the start reporting time, call the terminal reporting management module setProgrammedInterval interface to set the reporting interval, and call the sendACK interface of the LRIT information management module to reply the receipt information to the data center; The processing flow of the stop position report request is as follows: after receiving the stop position report request, the terminal position reporting management module setProgrammedStatus interface is called to set the scheduled position reporting status to off, the terminal position reporting management module setProgrammedStartTime and setProgrammedInterval interfaces are called to set the start position reporting time and position reporting interval parameters to the initial state, and the LRIT information sending management module sendACK interface is called to reply the receipt information to the data center; The processing flow of the paging location request is as follows: after receiving the paging location request, the makeReport interface of the LRIT information management module is called to generate the response LRIT information, and the sendReport interface is called to send the LRIT information.

6. The BeiDou LRIT terminal for ship remote identification and tracking based on the BeiDou RDSS system according to claim 1, characterized in that: The instructions that the LRIT request receiving and processing module can parse include single call location instruction, setting 15-minute timed report instruction, setting 30-minute timed report instruction, setting 60-minute timed report instruction, setting 3-hour timed report instruction, setting 6-hour timed report instruction, setting 12-hour timed report instruction, setting 24-hour timed report instruction, and closing timed report instruction.

7. The shipborne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system according to claim 6 is characterized by: After receiving the single call location instruction, the LRIT request receiving and processing module returns a LRIT information to the LRIT data center through the LRIT information sending queue management module; after receiving the timing report instruction, the LRIT request receiving and processing module returns the LRIT information to the LRIT data center at a specified interval through the LRIT information sending queue management module; after receiving the closing timing report instruction, the LRIT request receiving and processing module stops the currently valid timing location report; The LRIT information sending queue management module uses userack confirmation combined with exponential backoff to return confirmation information to the LRIT data center for the instructions received by the LRIT request receiving and processing module, and receives a secondary confirmation message from the LRIT data center. If the secondary confirmation message is not received, it automatically resends the attempt.

8. The BeiDou LRIT terminal for ship remote identification and tracking based on the BeiDou RDSS system according to claim 1, characterized in that: When the Beidou LRIT terminal triggers the information sending function of the LRIT information sending management module due to a single call request or a scheduled position report from the LRIT data center, it first obtains the LRIT information through the Beidou GNSS / RDSS unit, and after successfully obtaining and encapsulating the information, it sends it to the LRIT data center through the RDSS short message link; If the Beidou GNSS / RDSS unit fails to obtain LRIT information, the Beidou LRIT terminal will obtain and encapsulate the LRIT information through the inertial navigation unit and then send it to the LRIT data center through the RDSS short message link; If the inertial navigation unit cannot obtain LRIT information, it will try the RDSS position reporting service and send the information to the LRIT data center.

9. The shipborne Beidou LRIT terminal for remote identification and tracking of ships based on the Beidou RDSS system according to claim 8, characterized in that: The LRIT information sending management module includes a makeReport interface for generating and encapsulating LRIT information, a sendReport interface for sending LRIT information, and a sendACK interface for sending ACK receipt information; The makeReport interface generates LRIT information based on the Beidou RDSS / GNSS unit and the inertial navigation unit and encapsulates it in a format; The sendReport interface calls the Beidou RDSS / GNSS unit’s position report and the short message sending interface sends LRIT information to the LRIT data center; The sendACK interface calls the short message sending interface of the Beidou RDSS / GNSS unit to send the start position report receipt and stop position report receipt information to the LRIT data center; In order to ensure the quality of LRIT information collected by the LRIT data center, the LRIT information sending management module adopts three-way handshake and exponential backoff to send LRIT information.

10. The BeiDou LRIT terminal for ship remote identification and tracking based on the BeiDou RDSS system according to claim 1, characterized in that: The user card management module performs LRIT service management on Beidou IC users, including authority management, Beidou service type management, and communication frequency management.

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