AIS (Automatic Identification System)-based ship auxiliary berthing and unberthing method and system

Abstract

The invention provides an AIS-based ship auxiliary berthing and departing method and system, and the method comprises the steps: firstly collecting and analyzing the AIS data of a ship, respectively extending from a GPS position point to an intersection point of a port edge and a starboard edge in a direction perpendicular to the longitudinal axis of a ship body, and respectively taking the intersection point as a port projection point and a starboard projection point; the latitude and longitude coordinates of the portboard and starboard projection points are calculated by adopting a specific calculation method; secondly, a rectangle which completely surrounds the whole outline of the ship and has the minimum area is constructed and serves as an external quadrangle of the ship, then an outline model of the ship is constructed, and external rectangular frames which are concentric and coaxial with the outline model of the ship are constructed at certain intervals in the direction from near to far away from the outline model of the ship so as to generate a plurality of sets of equidistant lines; calculating a normal velocity component and a radial velocity component; and finally, establishing an auxiliary berthing and leaving decision function based on the ship-shore distance, the normal velocity component and the radial velocity component, and assisting a captain or pilot to realize auxiliary berthing and leaving decision of the ship according to the auxiliary berthing and leaving decision function.

Description

Technical Field

[0001] The present invention relates to the technical field of shipping traffic, and particularly to a method and system for ship assisted berthing and unberthing based on AIS. Background Art

[0002] Ship berthing and unberthing are crucial links in shipping activities, involving operations such as the entry, docking, and departure of ships at ports. With the rapid development of global trade, the volume of ship transportation has been increasing year by year, and the complexity and diversity of port operations have also increased accordingly. During the process of ship berthing and unberthing, various factors need to be considered, such as tidal changes, wind and wave effects, channel conditions, and the dynamics of other ships. These factors not only affect the efficiency of berthing and unberthing, but may even pose safety risks such as collisions and groundings, endangering the safety of ships and their cargoes.

[0003] Berthing and unberthing safety is a key link in ensuring shipping safety. Due to the large size and certain inertia of ships, once an accident occurs, it may lead to serious property losses and ecological environment damage. Especially in large ports and busy waterways, the maneuverability of ships is more difficult and the potential safety hazards increase. Ensuring safety during the berthing and unberthing process not only helps to reduce accidents and improve port operation efficiency, but also helps to maintain the reputation and sustainable development of the shipping industry. Therefore, it is particularly important to develop and apply advanced assisted berthing and unberthing technologies to improve the accuracy and safety of ship control.

[0004] At present, certain progress has been made in international ship berthing and unberthing technologies, mainly focusing on intelligent assistance systems, automated navigation technologies, and the application of high-tech sensors. For example, some countries have developed ship control systems based on artificial intelligence, which can monitor the ship's status and surrounding environment in real time and optimize the operation path through algorithms. In China, although the relevant technologies started relatively late, they have gradually received attention in recent years. Multiple ports and research institutions have begun to explore the application of intelligent berthing systems and develop related auxiliary equipment and algorithms to improve the safety and efficiency of berthing. However, considering the maturity of technologies, the extensiveness of applications, and market demands, there is still room for further optimization and improvement. Summary of the Invention

[0005] To solve the problems in existing ship berthing and unberthing technologies, such as numerous devices, complex installation, and inability to restore the true size of ships, the present invention provides a method for ship assisted berthing and unberthing based on AIS, which can provide a simple, intuitive, accurate, and reliable berthing and unberthing assistance means for the driver in real time, for assisting in berthing and unberthing decision-making, and is simple to install, convenient to implement, can restore the true size of the ship, effectively improving the safety of ship navigation, as well as the efficiency and accuracy of berthing and unberthing operations. The present invention also relates to a system for ship assisted berthing and unberthing based on AIS.

[0006] The technical solution of the present invention is as follows:

[0007] A ship assisted berthing and unberthing method based on AIS, characterized by comprising the following steps:

[0008] AIS data acquisition and parsing step: Obtain the original AIS message data of the ship through the on-board VDR signal machine, and then parse the original AIS message data to extract AIS navigation dynamic data and AIS static data. The AIS navigation dynamic data includes the longitude and latitude coordinates of the GPS position points, the ship's heading angle, the actual heading, and the actual speed; the AIS static data includes the bow length, and the distances between the GPS position points and the left side, right side, bow, and stern of the ship, which are used as the left side distance, right side distance, bow distance, and stern distance respectively;

[0009] Left and right side projection point coordinate calculation step: Extend the GPS position points along the direction perpendicular to the longitudinal axis of the hull to the intersections of the left side edge and the right side edge respectively, and use them as the left side projection point and the right side projection point. Calculate the first azimuth angle of the left side projection point relative to the GPS position point and the second azimuth angle of the right side projection point relative to the GPS position point according to the ship's heading angle. Calculate the longitude and latitude coordinates of the left side projection point according to the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the left side distance, and calculate the longitude and latitude coordinates of the right side projection point according to the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the right side distance;

[0010] Ship contour model construction step: Based on the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship, construct a rectangle with the smallest area that completely encloses the overall contour of the ship as the circumscribed quadrilateral of the ship; Based on the calculated longitude and latitude coordinates of the left and right side projection points, the ship's heading angle, bow distance, stern distance, and bow length, and according to the calculation principle of the longitude and latitude coordinates in the left and right side projection point coordinate calculation step, calculate the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the circumscribed quadrilateral of the ship associated with the left and right side projection points respectively; And calculate the longitude and latitude coordinates of the bow vertex of the ship according to the longitude and latitude coordinates of the left front vertex and the right front vertex of the circumscribed quadrilateral of the ship; Furthermore, construct a ship contour model based on the longitude and latitude coordinates of the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship;

[0011] Steps for constructing isometric lines and calculating normal and radial velocities: Based on the constructed own-ship contour model, circumscribed rectangular frames that are concentric and coaxial with the own-ship contour model are constructed at regular intervals in the direction from near to far from the own-ship contour model, generating multiple circumscribed rectangular frames as multiple groups of isometric lines around the own-ship contour model; and the angular difference between the bow direction and the actual course is calculated based on the actual speed, actual course, and own-ship bow angle; and the normal velocity component and radial velocity component are calculated respectively according to the angular difference and the actual speed.

[0012] Steps for assisting in berthing and unberthing decisions: The own-ship contour model, multiple groups of isometric lines around the own-ship contour model, the normal velocity component, and the radial velocity component are displayed in real time on the map, and the ship-shore distance between the own ship and the shore end is extracted in real time based on the multiple groups of isometric lines on the map. An auxiliary berthing and unberthing decision function is established based on the ship-shore distance, the normal velocity component, and the radial velocity component. According to the auxiliary berthing and unberthing decision function, the master or pilot is assisted in judging whether the own ship needs to decelerate to complete the auxiliary berthing and unberthing decisions of the ship.

[0013] Preferably, in the step of constructing the own-ship contour, according to the calculation principle of the longitude and latitude coordinates in the calculation step of the left and right projection point coordinates, the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the circumscribed quadrilateral of the own ship associated with the left and right projection points are calculated respectively, specifically including:

[0014] The longitude and latitude coordinates of the right front vertex of the circumscribed quadrilateral of the own ship associated with the right projection point are calculated according to the longitude and latitude coordinates of the right projection point, the own-ship bow angle, and the bow distance; and the longitude and latitude coordinates of the right side vertex of the own ship associated with the right projection point are calculated according to the longitude and latitude coordinates of the right projection point, the own-ship bow angle, the bow distance, and the bow length; then the third azimuth angle of the right stern vertex of the own ship relative to the right projection point is calculated according to the own-ship bow angle; and the longitude and latitude coordinates of the right stern vertex of the own ship associated with the right projection point are calculated according to the longitude and latitude coordinates of the right projection point, the third azimuth angle, and the stern distance;

[0015] The longitude and latitude coordinates of the left front vertex of the circumscribed quadrilateral of the own ship associated with the left projection point are calculated according to the longitude and latitude coordinates of the left projection point, the own-ship bow angle, and the bow distance; and the longitude and latitude coordinates of the left side vertex of the own ship associated with the left projection point are calculated according to the longitude and latitude coordinates of the left projection point, the own-ship bow angle, the bow distance, and the bow length; then the fourth azimuth angle of the left stern vertex of the own ship relative to the left projection point is calculated according to the own-ship bow angle; and the longitude and latitude coordinates of the left stern vertex of the own ship associated with the left projection point are calculated according to the longitude and latitude coordinates of the left projection point, the fourth azimuth angle, and the stern distance.

[0016] Preferably, in the step of constructing the isometric lines and calculating the normal and radial velocities, the construction of the circumscribed rectangular frame specifically includes:

[0017] Respectively obtain the perpendicular distances from the GPS position point to the left and right frames of the circumscribed rectangular frame, which are used as the first perpendicular distance and the second perpendicular distance respectively. Calculate the longitude and latitude coordinates of the perpendicular intersection point between the GPS position point and the left frame of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the first perpendicular distance; and calculate the longitude and latitude coordinates of the perpendicular intersection point between the GPS position point and the right frame of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the second perpendicular distance.

[0018] Then, calculate the longitude and latitude coordinates of the left front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point on the left frame, the heading angle of the ship, and the bow distance; calculate the longitude and latitude coordinates of the left rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point on the left frame, the heading angle of the ship, and the stern distance; calculate the longitude and latitude coordinates of the right front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point on the right frame, the heading angle of the ship, and the bow distance; calculate the longitude and latitude coordinates of the right rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point on the right frame, the heading angle of the ship, and the stern distance. Furthermore, construct a circumscribed rectangular frame concentric and coaxial with the ship's contour model based on the longitude and latitude coordinates of the left front vertex, left rear vertex, right front vertex, and right rear vertex of the circumscribed rectangular frame.

[0019] Preferably, in the step of assisting in berthing and unberthing decision-making, the specific method of assisting the captain or pilot to judge whether the ship needs to decelerate according to the auxiliary berthing and unberthing decision-making function includes:

[0020] If the ship-shore distance is less than the first distance threshold, and the normal velocity component or the radial velocity component is greater than the preset first velocity threshold, then deceleration is required; if the ship-shore distance is greater than the first distance threshold and less than or equal to the second distance threshold, and the normal velocity component or the radial velocity component is greater than the preset second velocity threshold, then deceleration is required; if the ship-shore distance is greater than the second distance threshold and less than or equal to the third distance threshold, and the normal velocity component or the radial velocity component is greater than the preset third velocity threshold, then deceleration is required; if the ship-shore distance is greater than the third distance threshold and less than or equal to the fourth distance threshold, and the normal velocity component or the radial velocity component is greater than the preset fourth velocity threshold, then deceleration is required.

[0021] Preferably, in the AIS data acquisition and parsing step, the AIS signal machine data of the ship itself is obtained through the on-board VDR signal machine as the AIS original message data. Then, the AIS original message data is connected to the isolated serial signal distributor through the AIS external wiring terminal of the on-board VDR signal machine. After that, it is converted into an Ethernet signal through the serial server via the RS485 serial port and then transmitted to the industrial-grade tablet all-in-one through the switch. The industrial-grade tablet all-in-one parses the AIS original message data to extract the AIS navigation dynamic data and AIS static data.

[0022] A ship auxiliary berthing system based on AIS, characterized in that it includes an AIS data acquisition and parsing module, a left and right projection point coordinate calculation module, a ship contour model construction module, an isometric line construction and normal and radial velocity calculation module, and an auxiliary berthing decision module, which are connected in sequence.

[0023] The AIS data acquisition and parsing module obtains the AIS original message data of the ship itself through the on-board VDR signal machine, and then parses the AIS original message data to extract the AIS navigation dynamic data and AIS static data. The AIS navigation dynamic data includes the longitude and latitude coordinates of the GPS position points, the ship's heading angle, the actual course, and the actual speed; the AIS static data includes the bow length, and the distances between the GPS position point coordinates and the ship's left side, right side, bow, and stern, which are respectively used as the left side distance, right side distance, bow distance, and stern distance.

[0024] The left and right projection point coordinate calculation module takes the intersections of the extensions from the GPS position points along the directions perpendicular to the longitudinal axis of the hull to the left and right edges as the left and right projection points respectively. According to the ship's heading angle, it calculates the first azimuth angle of the left projection point relative to the GPS position point and the second azimuth angle of the right projection point relative to the GPS position point respectively. According to the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the left side distance, it calculates the longitude and latitude coordinates of the left projection point, and according to the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the right side distance, it calculates the longitude and latitude coordinates of the right projection point.

[0025] The ship contour model construction module constructs a rectangle with the smallest area that completely encloses the overall contour of the ship based on the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship, and uses it as the circumscribed quadrilateral of the ship. Based on the calculated longitude and latitude coordinates of the left side projection point and the right side projection point, the ship's heading angle, bow distance, stern distance, and bow length, and according to the calculation principle of the longitude and latitude coordinates in the left side and right side projection point coordinate calculation module, the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship's circumscribed quadrilateral associated with the left side projection point and the right side projection point are calculated respectively. And the longitude and latitude coordinates of the bow vertex of the ship are calculated based on the longitude and latitude coordinates of the left front vertex and the right front vertex of the ship's circumscribed quadrilateral. Furthermore, a ship contour model is constructed based on the longitude and latitude coordinates of the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship.

[0026] The isometric line construction and normal and radial velocity calculation module, based on the constructed ship contour model, constructs circumscribed rectangular frames concentric and coaxial with the ship contour model at regular intervals in the direction from near to far from the ship contour model, generates multiple circumscribed rectangular frames and uses them as multiple groups of isometric lines around the ship contour model. And calculates the angle difference between the ship's heading and the actual course based on the actual speed, actual course, and the ship's heading angle. And calculates the normal velocity component and the radial velocity component respectively according to the angle difference and the actual speed.

[0027] The auxiliary berthing and unberthing decision module displays the ship contour model, multiple groups of isometric lines around the ship contour model, the normal velocity component, and the radial velocity component on the map in real time, and extracts the ship-shore distance between the ship and the shore end in real time based on the multiple groups of isometric lines on the map. An auxiliary berthing and unberthing decision function is established based on the ship-shore distance, the normal velocity component, and the radial velocity component, and the auxiliary berthing and unberthing decision function is used to assist the captain or pilot in judging whether the ship needs to decelerate to complete the auxiliary berthing and unberthing decision of the ship.

[0028] Preferably, in the ship contour construction module, according to the calculation principle of the longitude and latitude coordinates in the left side and right side projection point coordinate calculation module, the specific calculation of the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship's circumscribed quadrilateral associated with the left side projection point and the right side projection point includes:

[0029] Calculate the longitude and latitude coordinates of the right front vertex of the circumscribed quadrilateral of the ship associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the right vertex of the ship associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the ship's heading angle, the bow distance, and the bow length; calculate the third azimuth angle of the right rear vertex of the ship's stern relative to the right projection point based on the ship's heading angle; and calculate the longitude and latitude coordinates of the right rear vertex of the ship's stern associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the third azimuth angle, and the stern distance.

[0030] Calculate the longitude and latitude coordinates of the left front vertex of the circumscribed quadrilateral of the ship associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the left vertex of the ship associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the ship's heading angle, the bow distance, and the bow length; calculate the fourth azimuth angle of the left rear vertex of the ship's stern relative to the left projection point based on the ship's heading angle; and calculate the longitude and latitude coordinates of the left rear vertex of the ship's stern associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the fourth azimuth angle, and the stern distance.

[0031] Preferably, in the isometric line construction and normal and radial velocity calculation module, the construction of the circumscribed rectangular frame specifically includes:

[0032] Respectively obtain the perpendicular distances from the GPS position point to the left and right borders of the circumscribed rectangular frame, which are used as the first perpendicular distance and the second perpendicular distance respectively. Calculate the longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the left border of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the first perpendicular distance; and calculate the longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the right border of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the second perpendicular distance.

[0033] Then calculate the longitude and latitude coordinates of the left front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the left border, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the left rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the left border, the ship's heading angle, and the stern distance; calculate the longitude and latitude coordinates of the right front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the right border, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the right rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the right border, the ship's heading angle, and the stern distance, and then construct a circumscribed rectangular frame concentric and coaxial with the ship's contour model based on the longitude and latitude coordinates of the left front vertex, left rear vertex, right front vertex, and right rear vertex of the circumscribed rectangular frame.

[0034] Preferably, in the auxiliary berthing and unberthing decision-making module, the process of using the auxiliary berthing and unberthing decision function to assist the captain or pilot in judging whether the ship needs to decelerate specifically includes:

[0035] If the ship-shore distance is less than the first distance threshold and the normal velocity component or the radial velocity component is greater than the preset first velocity threshold, deceleration is required; if the ship-shore distance is greater than the first distance threshold and less than or equal to the second distance threshold, and the normal velocity component or the radial velocity component is greater than the preset second velocity threshold, deceleration is required; if the ship-shore distance is greater than the second distance threshold and less than or equal to the third distance threshold, and the normal velocity component or the radial velocity component is greater than the preset third velocity threshold, deceleration is required; if the ship-shore distance is greater than the third distance threshold and less than or equal to the fourth distance threshold, and the normal velocity component or the radial velocity component is greater than the preset fourth velocity threshold, deceleration is required.

[0036] Preferably, the AIS data acquisition and parsing module is implemented based on the original shipborne VDR signal machine and the newly added serial signal distributor, serial server, switch, and industrial-grade tablet integrated computer installed on the ship. The AIS signal machine data of the ship is obtained through the shipborne VDR signal machine as the AIS original message data, and then the AIS original message data is connected to the serial signal distributor through the AIS external wiring terminal of the shipborne VDR signal machine. After that, the serial server converts the data from RS485 serial port to Ethernet signal and then transmits it to the industrial-grade tablet integrated computer through the switch. The industrial-grade tablet integrated computer parses the AIS original message data to extract the AIS navigation dynamic data and AIS static data;

[0037] The left and right projection point coordinate calculation module, the ship contour model construction module, the equidistant line construction and normal and radial velocity calculation module, and the auxiliary berthing and unberthing decision-making module are all integrated in the industrial-grade tablet integrated computer. The beneficial effects of the present invention are:

[0038] A ship auxiliary berthing and unberthing method based on AIS provided by the present invention first obtains the original AIS message data of the ship and parses and extracts it into AIS navigation dynamic data and AIS static data, and extends the intersection points from the GPS position point along the direction perpendicular to the longitudinal axis of the hull to the left hull edge and the right hull edge respectively as the left projection point and the right projection point. Then, based on the obtained AIS data and using a specific calculation method, the longitude and latitude coordinates of the left and right projection points are calculated respectively, which can accurately determine the edge position of the ship and provide accurate data for the subsequent contour model construction. Then, based on the bow vertex, left vertex, right vertex, left stern vertex and right stern vertex of the ship, a rectangle with the smallest area that completely encloses the overall contour of the ship is constructed as the circumscribed quadrilateral of the ship, and the longitude and latitude coordinates of the left front vertex, right front vertex, left vertex, right vertex, left stern vertex and right stern vertex of the circumscribed quadrilateral of the ship associated with the left and right projection points are calculated respectively using the above calculation principle of longitude and latitude coordinates, and the longitude and latitude coordinates of the bow vertex of the ship are calculated; furthermore, based on the longitude and latitude coordinates of the bow vertex, left vertex, right vertex, left stern vertex and right stern vertex of the ship, the contour model of the ship is accurately constructed; then, on the basis of the constructed contour model of the ship, a circumscribed rectangular frame concentric and coaxial with the contour model of the ship is constructed at a certain distance in the direction from near to far from the contour model of the ship as multiple groups of equidistant lines around the contour model of the ship, which can evaluate the safety distance between the ship and the surrounding environment in real time and ensure navigation safety; and the normal velocity component and the radial velocity component are calculated, which can analyze the motion state of the ship in real time and provide data support for the auxiliary berthing and unberthing decision-making; finally, the contour model of the ship, multiple groups of equidistant lines around the contour model of the ship, the normal velocity component and the radial velocity component are displayed in real time on the map, and the ship-shore distance between the ship and the shore end is extracted in real time based on the multiple groups of equidistant lines on the map. An auxiliary berthing and unberthing decision function is established based on the ship-shore distance, the normal velocity component and the radial velocity component. According to the auxiliary berthing and unberthing decision function, the captain or pilot is assisted to judge whether the ship needs to decelerate to complete the auxiliary berthing and unberthing decision of the ship. By integrating AIS data and real-time calculation, a low-cost and high-precision auxiliary decision-making scheme is provided, effectively improving the safety of ship navigation, as well as the efficiency and accuracy of berthing and unberthing operations.

[0039] The present invention only needs to access and parse the AIS raw message data of the on-board VDR signal machine, and the construction area involved is limited to the equipment room or the bridge. Compared with some other current methods that require adding new sensors around the ship, it is simpler, which is conducive to installation, implementation, popularization and application. Moreover, the real ship size in AIS (the bow length, and the distances between the GPS position points and the left and right sides, bow and stern of the ship, namely the left side distance, right side distance, bow distance and stern distance) is used to model the ship, restoring the real size of the ship 1:1, and drawing equidistant lines around the ship, visualizing and digitizing the ship-to-shore distance, speed, etc. during the berthing and unberthing processes, providing important data support for berthing and unberthing. In addition, combined with the map, the ship model and quantitative data during the berthing and unberthing processes are displayed in real time on the map, which can provide a simple, intuitive, accurate and reliable berthing and unberthing assistance means for the driver to assist in berthing and unberthing decision-making. The present invention does not require additional sensors, is easy to install, and significantly improves the safety, efficiency and accuracy of berthing and unberthing through real-scale modeling and quantitative display, and is applicable to various ships and port scenarios.

[0040] The present invention also relates to a ship auxiliary berthing and unberthing system based on AIS. This system corresponds to the above-mentioned ship auxiliary berthing and unberthing method based on AIS, and can be understood as a system for implementing the above-mentioned ship auxiliary berthing and unberthing method based on AIS. It includes an AIS data acquisition and parsing module, a left and right side projection point coordinate calculation module, a ship contour model construction module, an equidistant line construction and normal and radial velocity calculation module, and an auxiliary berthing and unberthing decision-making module that are connected in sequence. Each module works in coordination with each other, and can provide a simple, intuitive, accurate and reliable berthing and unberthing assistance means for the driver in real time to assist in berthing and unberthing decision-making. Moreover, it is simple to install and convenient to implement, can restore the real size of the ship, and effectively improves the safety of ship navigation, as well as the efficiency and accuracy of berthing and unberthing operations. Description of the Drawings

[0041] Figure 1 is the flow chart of the ship auxiliary berthing and unberthing method based on AIS of the present invention.

[0042] Figure 2 is the hardware support diagram of the ship auxiliary berthing and unberthing method based on AIS of the present invention, and at the same time is the hardware connection diagram of the ship auxiliary berthing and unberthing system based on AIS.

[0043] Figure 3 is the schematic diagram of the AIS raw message data parsing of the present invention.

[0044] Figure 4 is the schematic diagram of the ship structure of the present invention.

[0045] Figure 5 is the schematic diagram of the ship contour model of the present invention.

[0046] Figure 6 It is a schematic diagram of multiple sets of equidistant lines of the contour model of the ship of the present invention and its surroundings.

[0047] Figure 7 It is a schematic diagram for calculating the normal velocity and radial velocity of the present invention.

[0048] Figure 8 It is a schematic diagram of the distances between multiple sets of equidistant lines around the contour model of the ship and the shore end. Specific implementation mode

[0049] The present invention will be described below in conjunction with the accompanying drawings.

[0050] The present invention relates to a ship-assisted berthing and unberthing method based on AIS. The flowchart of this method is as Figure 1 shown, and it sequentially includes the following steps:

[0051] I. AIS data acquisition and parsing step: Obtain the original AIS message data of the ship through the on-board VDR signal machine, and then parse the original AIS message data to extract AIS navigation dynamic data and AIS static data. The AIS navigation dynamic data includes the longitude and latitude coordinates of the GPS position points, the ship's heading angle, the actual course, and the actual speed; the AIS static data includes the bow length, and the distances between the GPS position points and the left side, right side, bow, and stern of the ship, which are respectively used as the left side distance, right side distance, bow distance, and stern distance.

[0052] Specifically, as Figure 2 shown, the hardware adopted by the ship-assisted berthing and unberthing method based on AIS of the present invention includes devices such as "original on-board VDR signal machine + serial signal distributor + serial server + switch + industrial-grade tablet all-in-one machine", etc. The process of this AIS data acquisition and parsing step is as follows: The original on-board VDR signal machine is responsible for receiving and aggregating signals from almost all navigation and navigation devices on the ship, saving and recording them, including all data of the ship's AIS signal machine, and providing an external interface. Through the AIS external wiring terminal of the VDR, the original AIS message data is connected to the isolated serial signal distributor, and a parallel signal is output synchronously to the serial server. The serial server converts the RS485 serial AIS original message data signal into an Ethernet signal and then connects it to the switch, and then transmits it to the industrial-grade tablet all-in-one machine for parsing. The basic idea of this step is:

[0053] 1) AIS data access and collection. Shipborne VDR (Voyage Data Recorder) and AIS (Automatic Identification System) are two important components of modern ship safety systems. VDR is a device for recording ship operation information, while AIS is a system for exchanging position information between ships and between ships and shore-based facilities. The main function of VDR is to record various important data during ship navigation, including navigation information, communication information, and ship operation conditions. This data helps with investigations and analysis after an accident. Modern VDR systems have the ability to integrate with AIS systems and can directly record the data transmitted by AIS. By extracting AIS data from VDR, ships can be monitored and managed in real time. Therefore, the system directly obtains AIS data from VDR through an isolated signal distributor, converts the serial port signal into an Ethernet signal through a serial port server, and accesses an industrial-grade tablet all-in-one computer through a switch for parsing and application.

[0054] 2) AIS raw message parsing. As Figure 3 shown, AIS raw messages are transmitted using compressed ASCII codes and comply with the NMEA0183 protocol. Currently, they are generally transmitted in the format of encrypted messages. AIS raw messages usually start with "!AIVDO" or "!AIVDM", where "!AIVDO" is the AIS of the ship itself and "!AIVDM" is the AIS of other ships. Whether it is the AIS of the ship itself or other ships, only the string at the beginning of the message is different, and the encoding rules and protocols followed are exactly the same. An AIS decoding function is written according to the AIS encoding rules and relevant protocols. The input parameter is the AIS raw message, and the output result is the clear text information of the ship parameters contained in the AIS. Let the AIS raw message be AIS0 and the decoding function be Decode(). Then the calculation formula for the decoding process is as follows:

[0055]

[0056] Or:

[0057]

[0058] As Figure 3As shown in the figure, the AIS static data and AIS navigation dynamic data of this ship refer to obtaining the message types of AIS according to the AIS parsing results, and then extracting the AIS static data and AIS navigation dynamic data from different messages. There are more than 20 types of AIS messages, which are numbered with Arabic numerals 1, 2, 3... respectively. The information on the ship's dimensions (the length of the bow, and the distances between the GPS position points and the left and right sides, bow, and stern of the ship, i.e., the left-side distance, right-side distance, bow distance, and stern distance) used in this invention belongs to the ship's static data (or navigation static data), which is included in Message 5, and the extraction result is shown in Equation (2). The longitude and latitude coordinates of the GPS position point, the ship's bow angle, actual course, actual speed, etc. belong to the ship's AIS navigation dynamic data, which are included in Messages 1, 2, and 3, and the extraction result is shown in Equation (1).

[0059] II. Calculation steps for the coordinates of the left and right projection points: Extend the lines from the GPS position point perpendicular to the longitudinal axis of the ship's hull to the intersections with the left and right edges of the ship's hull respectively, and take them as the left and right projection points. Calculate the first azimuth angle of the left projection point relative to the GPS position point and the second azimuth angle of the right projection point relative to the GPS position point according to the ship's bow angle, and calculate the longitude and latitude coordinates of the left projection point based on the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the left-side distance, and calculate the longitude and latitude coordinates of the right projection point based on the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the right-side distance.

[0060] Specifically, as Figure 4 shown, let the GPS position point in the ship's AIS be P0, and set the length of the bow, and the distances between the GPS position point and the left and right sides, bow, and stern of the ship, i.e., the left-side distance, right-side distance, bow distance, and stern distance as d l 、d r 、d h 、d b . Let the bow vertex, right-side vertex, right stern vertex, left stern vertex, and left-side vertex of the ship be P1, P2, P3, P4, P5 respectively, and let the ship's bow angle be Hog. Extend the lines from point P0 perpendicular to the longitudinal axis of the ship's hull to the intersections with the left and right edges of the ship's hull respectively, and take them as the left projection point P l0 and the right projection point P r0 . First, calculate the longitude and latitude coordinates of point P l0 according to P0. According to the known conditions and plane geometry relationships, the calculation formula for the first azimuth angle θ l0 of P l relative to point P0 is as follows:

[0061]

[0062] Let \(R\) be the radius of the earth, approximately 6,371 kilometers, and \((lon0, lat0)\) be the longitude and latitude coordinates of the GPS position point \(P0\). According to the spherical cosine theorem, given the longitude and latitude coordinates \((lon0, lat0)\) of a point \(P0\) and the distance \(d\) r0 and the angle \(\theta\) l with respect to this point, the longitude and latitude coordinates \((lon\) l of point \(P\) l0 can be deduced and calculated according to the following formula: l0 , lat l0 ).

[0063]

[0064] Then, based on \(P0\), calculate the longitude and latitude coordinates of \(P\). r0 According to the known conditions and plane geometry relationships, the formula for calculating the second azimuth angle \(\theta\) r0 of point \(P\) relative to point \(P0\) is as follows: r

[0065]

[0066] Let \(R\) be the radius of the earth, approximately 6,371 kilometers, and \((lon0, lat0)\) be the longitude and latitude coordinates of the GPS position point \(P0\). According to geographical knowledge, given the longitude and latitude coordinates \((lon0, lat0)\) of a point \(P0\) and the distance \(d\) r0 and the angle \(\theta\) r with respect to this point, the longitude and latitude coordinates \((lon\) r of point \(P\) r0 can be deduced, and the calculation formula is as follows: r0 , lat r0 )

[0067]

[0068] III. Steps for constructing the outline model of the ship: Based on the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship, construct a rectangle with the smallest area that completely encloses the overall outline of the ship and use it as the circumscribed quadrilateral of the ship; based on the calculated longitude and latitude coordinates of the left and right side projection points, the ship's heading angle, bow distance, stern distance, and bow length, and according to the calculation principle of the longitude and latitude coordinates in the calculation steps of the left and right side projection point coordinates, calculate the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship's circumscribed quadrilateral associated with the left and right side projection points; and calculate the longitude and latitude coordinates of the bow vertex of the ship based on the longitude and latitude coordinates of the left front vertex and right front vertex of the ship's circumscribed quadrilateral; furthermore, construct the outline model of the ship based on the longitude and latitude coordinates of the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship.

[0069] Specifically, first, based on the bow vertex, starboard vertex, port vertex, stern port vertex, and stern starboard vertex of the ship, a rectangle with the smallest area that completely encloses the overall outline of the ship is constructed and used as the circumscribed quadrilateral of the ship. Let the right front vertex of the circumscribed quadrilateral of the ship be P hr , according to the ship structure and Figure 4 it can be known that P hr is on the same straight line as the starboard vertex P2 and the stern starboard vertex P3 of the ship and is parallel to the ship's body direction. The distance from point P2 to P hr is the length L of the triangular bow h . Then the calculation formula for the longitude and latitude coordinates of point P hr is as follows:

[0070]

[0071] where lon hr is the longitude coordinate of P hr , and lat hr is the latitude coordinate of P hr .

[0072] The calculation formula for the longitude and latitude coordinates of point P2 is as follows:

[0073]

[0074] where lon2 is the longitude coordinate of P2 and lat2 is the latitude coordinate of P2.

[0075] The stern starboard vertex P3 of the ship is in the opposite direction of the bow from the known point P r0 . Its third azimuth angle θ r0 relative to point P b is calculated as follows:

[0076]

[0077] Then, based on the longitude and latitude coordinates of the known point P r0 and the known stern distance and third azimuth angle, the calculation formula for the longitude and latitude coordinates (lon3, lat3) of point P3 is as follows:

[0078]

[0079] Symmetric to the starboard side, let the left front vertex of the circumscribed quadrilateral of the ship be P hl . According to the ship structure and Figure 4 it can be known that P hl is on the same straight line as the port vertex P5 and the stern port vertex P4 of the ship and is parallel to the ship's body direction. The distance from point P5 to P hl is the length L of the triangular bowh Then P hl The calculation formula for the longitude and latitude coordinates of point P is as follows:

[0080]

[0081] Among them, lon hl is the longitude coordinate of P hl , and lat hl is the latitude coordinate of P hl .

[0082] The calculation formula for the longitude and latitude coordinates of point P5 is as follows:

[0083]

[0084] Among them, lon5 is the longitude coordinate of P5, and lat5 is the latitude coordinate of P5.

[0085] The left vertex P4 at the stern of the ship is in the opposite direction of the known point P l0 towards the bow, and its fourth azimuth angle relative to point P l0 is equal to the third azimuth angle θ r0 of P3 relative to P b . Then, based on the longitude and latitude of the known point P l0 , the distance d l0 to P b (i.e., the stern distance) and the angle θ l0 relative to P b , the calculation formula for the longitude and latitude coordinates (lon4, lat4) of point P4 can be obtained as follows:

[0086]

[0087] The coordinate point at the exact middle of the bow, that is, the vertex of the bow (or the middle point of the bow, simply referred to as the bow point) P1, and the two vertices P hr and P hl of the circumscribed quadrilateral of the ship are on the same straight line, and P hr and P hl are centrosymmetric about P1. Then, based on the coordinate points of the two known points P hr and P hl , the calculation formula for the longitude and latitude coordinates (lon1, lat1) of the bow point P1 can be obtained as follows:

[0088]

[0089] So far, the coordinate calculations of the five edge vertices of the ship, namely the bow point P1, the right vertex P2, the right stern vertex P3, the left stern vertex P4, and the left vertex P5, are completed. Connecting these five points constructs the contour model of the ship.

[0090] IV. Steps for constructing equidistant lines and calculating normal and radial velocities. Based on the constructed contour model of the own ship, circumscribed rectangular frames that are concentric and coaxial with the contour model of the own ship are constructed at regular intervals in the direction from near to far from the contour model of the own ship, generating multiple circumscribed rectangular frames and using them as multiple sets of equidistant lines around the contour model of the own ship; and the angular difference between the bow direction and the actual course is calculated based on the actual speed, actual course, and the bow angle of the own ship; and the normal velocity component and radial velocity component are calculated respectively according to the angular difference and the actual speed.

[0091] This step can also be understood as the step for constructing equidistant lines and the step for calculating normal and radial velocities. Among them,

[0092] 1) Step for constructing equidistant lines: Specifically, as Figure 5 and 6 shown, multiple sets of equidistant lines around the contour model of the own ship refer to calculating multiple sets of equidistant lines at a certain distance and drawing them around the own ship to facilitate judging the distance of the target approaching the own ship, achieving the effect of what you see is what you get. By constructing on the basis of the contour model of the own ship, circumscribed rectangular frames that are concentric and coaxial with the contour model of the own ship are constructed at intervals of 5 meters in the direction from near to far from the contour model of the own ship, serving as multiple sets of equidistant lines around the contour model of the own ship, that is, at intervals of 5 meters, a total of 10 equidistant lines of 5 meters, 10 meters, 15 meters, 20 meters, 25 meters, 30 meters, 35 meters, 40 meters, 45 meters, and 50 meters are calculated respectively and displayed with circumscribed rectangular frames.

[0093] Taking the calculation of the 5 - meter equidistant line as an example, the other equidistant lines are calculated in the same way. Assume that the four vertices of the 5 - meter circumscribed rectangular frame of the own ship, namely the right - front, right - rear, left - rear, and left - front vertices, are sorted clockwise and are marked with P 51 , P 52 , P 53 , P 54 respectively, and this circumscribed rectangular frame is concentric and coaxial with the own ship. Given that the perpendicular distance from the GPS coordinate point P0 of the own ship to the starboard side is d r , then the perpendicular distance to the right - hand side frame of the 5 - meter circumscribed rectangular frame is d r + 5. Let the perpendicular intersection point of P0 and the right - hand side frame of the 5 - meter circumscribed rectangular frame be P 5r , then the calculation formula for the longitude and latitude coordinates of P 5r is as follows:

[0094]

[0095] where lon 5r is the longitude coordinate of P 5r , lat 5r is the latitude coordinate of P 5r , and θ r has been calculated during the process of constructing the contour model of the own ship.

[0096] According to the relationship that the 5-meter circumscribed rectangle is concentric and coaxial with the ship, point P 51 , P 52 and P 5r are on the same straight line, and the distance from P 51 to P 5r is d h + 5, and the angle is Hog. Then the calculation formula for the longitude and latitude coordinates (lon 51 , lat 51 ) of P 51 is as follows:

[0097]

[0098] The distance from P 52 to P 5r is d b + 5, and the angle is θ b . Then the calculation formula for the longitude and latitude coordinates (lon 52 , lat 52 , lat 52 ) of P

[0099]

[0100] Given that the perpendicular distance from the GPS position point P0 of the ship to the port side is d l , then the perpendicular distance to the left border of the 5-meter circumscribed rectangle is d l + 5. Let the intersection point of the perpendicular line from P0 to the left border of the 5-meter circumscribed rectangle be P 5l , and the angle θ 5l of P l relative to P0 has been calculated during the process of constructing the ship's contour model. Then the calculation formula for the longitude and latitude coordinates (lon 5l , lat 51 , lat 51 ) of P

[0101]

[0102] From the above process, it can be seen that the left rear vertex P 53 , the left front vertex P 54 of the left border of the 5-meter circumscribed rectangle and P 5l are on the same straight line, and the distance from P 53 to P 5l is d b + 5, and the angle is θ b . Then the calculation formula for the longitude and latitude coordinates (lon 53 , lat 53 , lat 53 ) of P

[0103]

[0104] P 54 At a distance of d relative to P 5l h +5, with an angle of Hog, then P 54 The longitude and latitude coordinates (lon 54 , lat 54 ) are calculated as follows:

[0105]

[0106] Thus far, the longitude and latitude coordinates of the four vertices P 51 , P 52 , P 53 and P 54 of the 5-meter circumscribed rectangle of this vessel have all been calculated. By directly connecting the lines on the map, the 5-meter equidistant line of this vessel can be obtained. For other distance equidistant lines, only the distance increment relative to the GPS coordinate point P0 needs to be adjusted and calculated according to the above method, which will not be repeated here.

[0107] 2) Calculation steps for normal velocity and radial velocity: Specifically, as Figure 7 shown, the calculation of the normal velocity and radial velocity of this vessel refers to calculating the velocity components of this vessel in the bow direction and the direction perpendicular to the bow based on the vessel's speed and heading. Among them, the velocity component in the bow direction is the normal velocity, and the velocity component perpendicular to the bow and pointing to the ship's side is the radial velocity. The normal velocity and radial velocity are of important reference value for assisting in berthing and unberthing.

[0108] Let the actual speed of this vessel be Sog and the actual course be Cog. Given the heading angle of this vessel, that is, the heading is Hog, then the angle difference θ d between the heading and the actual course is calculated as follows:

[0109]

[0110] According to the perpendicular relationship between the normal and the radial and the principle of trigonometric functions, the normal velocity component Sog head is calculated as follows:

[0111] Sog head = Sog × cos(θ d ) (22)

[0112] The radial velocity component Sog side is calculated as follows:

[0113] Sog side = Sog × sin(θ d ) (23)

[0114] ​V. Auxiliary approach and departure decision-making steps: The contour model of the ship, multiple sets of equidistant lines around the contour model of the ship, the normal velocity component, and the radial velocity component are displayed in real time on the map. Based on the multiple sets of equidistant lines on the map, the ship-shore distance between the ship and the shore end is extracted in real time. An auxiliary approach and departure decision-making function is established based on the ship-shore distance, the normal velocity component, and the radial velocity component. According to the auxiliary approach and departure decision-making function, the captain or pilot is assisted to determine whether the ship needs to decelerate to complete the auxiliary approach and departure decision-making of the ship.

[0115] Preferably, if the ship-shore distance is less than the first distance threshold (e.g., 5 m), and the normal velocity component Sog head or the radial velocity component Sog side is greater than the preset first velocity threshold T5, deceleration is required; if the ship-shore distance is greater than the first distance threshold (e.g., 5 m) and less than or equal to the second distance threshold (e.g., 15 m), and the normal velocity component Sog head or the radial velocity component Sog side is greater than the preset second velocity threshold T 15 , deceleration is required; if the ship-shore distance is greater than the second distance threshold (e.g., 15 m) and less than or equal to the third distance threshold (e.g., 30 m), and the normal velocity component Sog head or the radial velocity component Sog side is greater than the preset third velocity threshold T 30 , deceleration is required; if the ship-shore distance is greater than the third distance threshold (e.g., 30 m) and less than or equal to the fourth distance threshold (e.g., 50 m), and the normal velocity component Sog head or the radial velocity Sog side component is greater than the preset fourth velocity threshold T 50 , deceleration is required.

[0116] Specifically, as Figure 8 shown, during the approach and departure process, when the ship is close enough to the shore and enters the critical moment of approach and departure, it is necessary to pay attention to the ship-shore distance and the approach speed at all times and adjust the telegraph order in real time to prevent collision accidents. Therefore, first, the contour model of the ship, multiple sets of equidistant lines around the contour model of the ship, the normal velocity component, and the radial velocity component are displayed in real time on the map at a 1:1 size, visually quantifying and displaying the ship-shore distance and the speed of the ship during approach and departure to better assist the captain or pilot in making decisions on ship approach and departure and reduce safety accidents. Based on the multiple sets of equidistant lines on the map, the ship-shore distance between the ship and the shore end is extracted in real time. An auxiliary approach and departure decision-making function is established based on the ship-shore distance, the normal velocity component, and the radial velocity component.

[0117] It is assumed that the upper limit of the allowable velocity in all directions in the range of 50 meters to 30 meters from the shore is T 50 , and the upper limit of the allowable velocity in the range of 30 meters to 15 meters is T30 The speed limit allowed in the range of 15 meters to 5 meters is T 15 The speed limit allowed within 5 meters is T5, and the auxiliary berthing and unberthing decision function is as follows:

[0118]

[0119] Among them, F is the decision function, d is the ship - shore distance, which can be directly estimated by visual inspection according to the equidistant ring where the shoreline is located.

[0120] The present invention also relates to a ship - assisted berthing and unberthing system based on AIS. This system corresponds to the above - mentioned ship - assisted berthing and unberthing method based on AIS, and can be understood as a system for implementing the above - mentioned method. The system includes an AIS data acquisition and parsing module, a port and starboard projection point coordinate calculation module, a ship contour model construction module, an isometric line construction and normal and radial velocity calculation module, and an auxiliary berthing and unberthing decision module, which are connected in sequence. Specifically,

[0121] The AIS data acquisition and parsing module obtains the original AIS message data of the ship through the on - board VDR signal machine, and then parses the original AIS message data to extract AIS navigation dynamic data and AIS static data. The AIS navigation dynamic data includes the longitude and latitude coordinates of the GPS position points, the ship's heading angle, the actual course, and the actual speed; the AIS static data includes the bow length, and the distances between the GPS position point coordinates and the port side, starboard side, bow, and stern of the ship, which are respectively used as the port side distance, starboard side distance, bow distance, and stern distance;

[0122] The port and starboard projection point coordinate calculation module takes the intersections of the extensions from the GPS position point along the direction perpendicular to the longitudinal axis of the hull to the port side edge and the starboard side edge as the port side projection point and the starboard side projection point respectively. According to the ship's heading angle, it calculates the first azimuth angle of the port side projection point relative to the GPS position point and the second azimuth angle of the starboard side projection point relative to the GPS position point respectively. According to the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the port side distance, it calculates the longitude and latitude coordinates of the port side projection point, and according to the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the starboard side distance, it calculates the longitude and latitude coordinates of the starboard side projection point;

[0123] The ship contour model construction module constructs a rectangle with the minimum area that completely encloses the overall contour of the ship based on the ship's bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex, and uses it as the circumscribed quadrilateral of the ship; based on the calculated longitude and latitude coordinates of the left side projection point and the right side projection point, the ship's heading angle, bow distance, stern distance, and bow length, and according to the calculation principle of the longitude and latitude coordinates in the left side and right side projection point coordinate calculation module, calculates the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship's circumscribed quadrilateral associated with the left side projection point and the right side projection point respectively; and calculates the longitude and latitude coordinates of the ship's bow vertex based on the longitude and latitude coordinates of the left front vertex and the right front vertex of the ship's circumscribed quadrilateral; and then constructs the ship contour model based on the longitude and latitude coordinates of the ship's bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex.

[0124] The isometric line construction and normal and radial velocity calculation module, based on the constructed ship contour model, constructs circumscribed rectangular frames that are concentric and coaxial with the ship contour model at regular intervals in the direction from near to far from the ship contour model, generates multiple circumscribed rectangular frames and uses them as multiple groups of isometric lines around the ship contour model; and calculates the angle difference between the ship's heading and the actual course based on the actual speed, actual course, and the ship's heading angle; and calculates the normal velocity component and the radial velocity component respectively according to the angle difference and the actual speed.

[0125] The auxiliary berthing and unberthing decision module displays the ship contour model, multiple groups of isometric lines around the ship contour model, the normal velocity component, and the radial velocity component on the map in real time, and extracts the ship-shore distance between the ship and the shore end in real time based on the multiple groups of isometric lines on the map, establishes an auxiliary berthing and unberthing decision function based on the ship-shore distance, the normal velocity component, and the radial velocity component, and assists the captain or pilot in judging whether the ship needs to decelerate according to the auxiliary berthing and unberthing decision function to complete the auxiliary berthing and unberthing decision of the ship.

[0126] Preferably, in the ship contour construction module, according to the calculation principle of the longitude and latitude coordinates in the left side and right side projection point coordinate calculation module, calculating the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship's circumscribed quadrilateral associated with the left side projection point and the right side projection point specifically includes:

[0127] Calculate the longitude and latitude coordinates of the right front vertex of the circumscribed quadrilateral of the ship associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the right vertex of the ship associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the ship's heading angle, the bow distance, and the length of the bow; calculate the third azimuth angle of the right rear vertex of the ship's stern relative to the right projection point based on the ship's heading angle; and calculate the longitude and latitude coordinates of the right rear vertex of the ship's stern associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the third azimuth angle, and the stern distance.

[0128] Calculate the longitude and latitude coordinates of the left front vertex of the circumscribed quadrilateral of the ship associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the left vertex of the ship associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the ship's heading angle, the bow distance, and the length of the bow; calculate the fourth azimuth angle of the left rear vertex of the ship's stern relative to the left projection point based on the ship's heading angle; and calculate the longitude and latitude coordinates of the left rear vertex of the ship's stern associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the fourth azimuth angle, and the stern distance.

[0129] Preferably, in the isometric line construction and normal and radial velocity calculation module, the construction of the circumscribed rectangular frame specifically includes:

[0130] Respectively obtain the perpendicular distances from the GPS position point to the left and right borders of the circumscribed rectangular frame, and use them as the first perpendicular distance and the second perpendicular distance respectively. Calculate the longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the left border of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the first perpendicular distance; and calculate the longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the right border of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the second perpendicular distance.

[0131] Then calculate the longitude and latitude coordinates of the left front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the left border, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the left rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the left border, the ship's heading angle, and the stern distance; calculate the longitude and latitude coordinates of the right front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the right border, the ship's heading angle, and the bow distance; calculate the longitude and latitude coordinates of the right rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the right border, the ship's heading angle, and the stern distance, and then construct a circumscribed rectangular frame concentric and coaxial with the ship's contour model based on the longitude and latitude coordinates of the left front vertex, left rear vertex, right front vertex, and right rear vertex of the circumscribed rectangular frame.

[0132] Preferably, in the auxiliary berthing and unberthing decision-making module, the specific steps of using the auxiliary berthing and unberthing decision function to assist the captain or pilot in judging whether the ship needs to decelerate include:

[0133] If the ship-shore distance is less than the first distance threshold and the normal velocity component or the radial velocity component is greater than the preset first velocity threshold, deceleration is required; if the ship-shore distance is greater than the first distance threshold and less than or equal to the second distance threshold and the normal velocity component or the radial velocity component is greater than the preset second velocity threshold, deceleration is required; if the ship-shore distance is greater than the second distance threshold and less than or equal to the third distance threshold and the normal velocity component or the radial velocity component is greater than the preset third velocity threshold, deceleration is required; if the ship-shore distance is greater than the third distance threshold and less than or equal to the fourth distance threshold and the normal velocity component or the radial velocity component is greater than the preset fourth velocity threshold, deceleration is required.

[0134] Preferably, as Figure 2 shown, the AIS data acquisition and parsing module is implemented based on the original shipborne VDR signal machine and the newly added serial signal distributor, serial server, switch, and industrial-grade all-in-one tablet installed on the ship. The AIS signal machine data of the ship is obtained through the shipborne VDR signal machine as the AIS original message data, and then the AIS original message data is connected to the serial signal distributor through the AIS external wiring terminal of the shipborne VDR signal machine, and then converted into an Ethernet signal through the RS485 serial port by the serial server and transmitted to the industrial-grade all-in-one tablet through the switch. The industrial-grade all-in-one tablet parses the AIS original message data to extract AIS navigation dynamic data and AIS static data;

[0135] The left and right projection point coordinate calculation module, the ship contour model construction module, the equidistant line construction and normal and radial velocity calculation module, and the auxiliary berthing decision module are all integrated in the industrial-grade all-in-one tablet.

[0136] The signal distribution of the present invention is reliable: the serial port signal distributor synchronously and parallelly distributes the AIS signals (AIS original message data signals) output by the shipborne VDR, ensuring that the signals can be stably transmitted to multiple systems, avoiding loss or interference during signal transmission, and ensuring the integrity of data acquisition; protocol conversion and adaptation: the serial port server converts the RS485 serial port AIS signal into an Ethernet signal, solving the compatibility problem between different interfaces and protocols, enabling data to be efficiently and stably transmitted in a network environment, and providing reliable front-end support for subsequent data processing; efficient network switching: the switch, as the data transmission hub, can achieve rapid data forwarding and switching, ensuring the high-speed transmission of AIS data from the serial port server to the industrial-grade tablet integrated machine, reducing data transmission latency, and meeting the real-time data processing requirements of the ship; and the device integration is convenient: this hardware combination method is connected through standard interfaces and protocols, facilitating integration into the existing ship equipment system, and is conducive to subsequent expansion or upgrade of some devices according to requirements, such as replacing the serial port server or industrial-grade tablet integrated machine with stronger performance, without affecting the overall system architecture; the system has good integration: it can be well integrated with other network-based or serial communication systems on the ship, and can further integrate various navigation data of the ship, laying a hardware foundation for building a more comprehensive and intelligent ship integrated management system.

[0137] The present invention provides an objective and scientific AIS-based ship assisted berthing and unberthing method and system, which can provide a simple, intuitive, accurate and reliable berthing and unberthing assistance means for the driver in real time for berthing and unberthing decision-making assistance, and is simple to install and convenient to implement, can restore the true size of the ship, effectively improving the safety of ship navigation, as well as the efficiency and accuracy of berthing and unberthing operations.

[0138] It should be noted that the above specific embodiments can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way. Therefore, although this specification has described the present invention in detail with reference to the drawings and embodiments, those skilled in the art should understand that the present invention can still be modified or equivalently replaced. In short, all technical solutions and their improvements that do not depart from the spirit and scope of the present invention should be covered by the protection scope of the present invention patent.

Claims

1. A ship assisted berthing and unberthing method based on AIS, characterized in that, Including the following steps: AIS data acquisition and parsing step: Obtain the AIS raw message data of the ship through the on-board VDR signal machine, and then parse the AIS raw message data to extract the AIS navigation dynamic data and AIS static data. The AIS navigation dynamic data includes the longitude and latitude coordinates of the GPS position points, the heading angle of the ship's bow, the actual heading, and the actual speed. The AIS static data includes the length of the ship's bow, and the distances between the GPS position points and the left side, right side, bow, and stern of the ship, which are respectively used as the left side distance, right side distance, bow distance, and stern distance; Calculation steps for the coordinates of the left and right side projection points: Extend the lines from the GPS position points perpendicular to the longitudinal axis of the hull to the intersections of the left and right side edges respectively, and use them as the left and right side projection points. Calculate the first azimuth angle of the left side projection point relative to the GPS position point and the second azimuth angle of the right side projection point relative to the GPS position point according to the heading angle of the ship. Calculate the longitude and latitude coordinates of the left side projection point based on the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the left side distance, and calculate the longitude and latitude coordinates of the right side projection point based on the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the right side distance; Steps for constructing the ship's contour model: Based on the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship, construct a rectangle with the smallest area that completely encloses the overall contour of the ship as the circumscribed quadrilateral of the ship. Based on the calculated longitude and latitude coordinates of the left and right side projection points, the heading angle of the ship, the bow distance, the stern distance, and the length of the ship's bow, and according to the calculation principle of the longitude and latitude coordinates in the calculation steps for the coordinates of the left and right side projection points, calculate the longitude and latitude coordinates of the left front vertex, right front vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the circumscribed quadrilateral of the ship associated with the left and right side projection points respectively. Calculate the longitude and latitude coordinates of the bow vertex of the ship based on the longitude and latitude coordinates of the left front vertex and right front vertex of the circumscribed quadrilateral of the ship. Then, construct the ship's contour model based on the longitude and latitude coordinates of the bow vertex, left side vertex, right side vertex, left stern vertex, and right stern vertex of the ship; Steps for constructing isometric lines and calculating normal and radial velocities: On the basis of the constructed ship's contour model, construct circumscribed rectangular frames concentric and coaxial with the ship's contour model at regular intervals in the direction from near to far from the ship's contour model, generate multiple circumscribed rectangular frames as multiple groups of isometric lines around the ship's contour model. Calculate the angle difference between the ship's bow direction and the actual heading based on the actual speed, actual heading, and the heading angle of the ship. Calculate the normal velocity component and radial velocity component according to the angle difference and the actual speed respectively; Steps for assisting berthing and unberthing decisions: The contour model of the ship, multiple sets of equally spaced lines around the contour model of the ship, the normal velocity component, and the radial velocity component are displayed in real time on the map. Based on the multiple sets of equally spaced lines on the map, the ship-shore distance between the ship and the shore end is extracted in real time. An auxiliary berthing and unberthing decision function is established based on the ship-shore distance, the normal velocity component, and the radial velocity component. According to the auxiliary berthing and unberthing decision function, it is used to assist the master or pilot in judging whether the ship needs to decelerate to complete the auxiliary berthing and unberthing decisions of the ship.

2. The method for assisting ship berthing and unberthing based on AIS according to claim 1, wherein In the steps of constructing the ship contour, according to the calculation principle of the longitude and latitude coordinates in the calculation steps of the projection point coordinates on the port side and starboard side, the longitude and latitude coordinates of the left front vertex, right front vertex, port side vertex, starboard side vertex, left stern vertex, and right stern vertex of the circumscribed quadrilateral of the ship associated with the port side projection point and starboard side projection point are calculated respectively, including: The longitude and latitude coordinates of the right front vertex of the circumscribed quadrilateral of the ship associated with the starboard side projection point are calculated according to the longitude and latitude coordinates of the starboard side projection point, the ship's heading angle, and the bow distance; and the longitude and latitude coordinates of the starboard side vertex of the circumscribed quadrilateral of the ship associated with the starboard side projection point are calculated according to the longitude and latitude coordinates of the starboard side projection point, the ship's heading angle, the bow distance, and the bow length; then the third azimuth angle of the right stern vertex of the ship relative to the starboard side projection point is calculated according to the ship's heading angle; and the longitude and latitude coordinates of the right stern vertex of the circumscribed quadrilateral of the ship associated with the starboard side projection point are calculated according to the longitude and latitude coordinates of the starboard side projection point, the third azimuth angle, and the stern distance. The longitude and latitude coordinates of the left front vertex of the circumscribed quadrilateral of the ship associated with the port side projection point are calculated according to the longitude and latitude coordinates of the port side projection point, the ship's heading angle, and the bow distance; and the longitude and latitude coordinates of the port side vertex of the circumscribed quadrilateral of the ship associated with the port side projection point are calculated according to the longitude and latitude coordinates of the port side projection point, the ship's heading angle, the bow distance, and the bow length; then the fourth azimuth angle of the left stern vertex of the ship relative to the port side projection point is calculated according to the ship's heading angle; and the longitude and latitude coordinates of the left stern vertex of the circumscribed quadrilateral of the ship associated with the port side projection point are calculated according to the longitude and latitude coordinates of the port side projection point, the fourth azimuth angle, and the stern distance.

3. The method for assisting ship berthing and unberthing based on AIS according to claim 1, wherein In the steps of constructing the equally spaced lines and calculating the normal and radial velocities, the construction of the circumscribed rectangular frame specifically includes: The perpendicular distances from the GPS position point to the left and right frames of the circumscribed rectangular frame are obtained respectively as the first perpendicular distance and the second perpendicular distance. The longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the left frame of the circumscribed rectangular frame are calculated according to the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the first perpendicular distance; and the longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the right frame of the circumscribed rectangular frame are calculated according to the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the second perpendicular distance. Calculate the longitude and latitude coordinates of the left front vertex of the circumscribed rectangle according to the longitude and latitude coordinates of the intersection point of the perpendicular line of the left border, the heading angle of the ship and the bow distance; calculate the longitude and latitude coordinates of the left rear vertex of the circumscribed rectangle according to the longitude and latitude coordinates of the intersection point of the perpendicular line of the left border, the heading angle of the ship and the stern distance; and calculate the longitude and latitude coordinates of the right front vertex of the circumscribed rectangle according to the longitude and latitude coordinates of the intersection point of the perpendicular line of the right border, the heading angle of the ship and the bow distance; calculate the longitude and latitude coordinates of the right rear vertex of the circumscribed rectangle according to the longitude and latitude coordinates of the intersection point of the perpendicular line of the right border, the heading angle of the ship and the stern distance, and then construct a circumscribed rectangle concentric and coaxial with the ship's contour model based on the longitude and latitude coordinates of the left front vertex, left rear vertex, right front vertex and right rear vertex of the circumscribed rectangle.

4. The AIS-based ship assisted berthing and unberthing method according to claim 1, wherein In the auxiliary berthing decision-making step, the specific steps of using the auxiliary berthing decision-making function to assist the captain or pilot in judging whether the ship needs to decelerate include: If the ship-shore distance is less than the first distance threshold and the normal velocity component or the radial velocity component is greater than the preset first velocity threshold, deceleration is required; if the ship-shore distance is greater than the first distance threshold and less than or equal to the second distance threshold, and the normal velocity component or the radial velocity component is greater than the preset second velocity threshold, deceleration is required; if the ship-shore distance is greater than the second distance threshold and less than or equal to the third distance threshold, and the normal velocity component or the radial velocity component is greater than the preset third velocity threshold, deceleration is required; if the ship-shore distance is greater than the third distance threshold and less than or equal to the fourth distance threshold, and the normal velocity component or the radial velocity component is greater than the preset fourth velocity threshold, deceleration is required.

5. The AIS-based ship assisted berthing and unberthing method according to any one of claims 1 to 4, characterized in that In the AIS data acquisition and parsing step, obtain the AIS signal machine data of the ship through the shipborne VDR signal machine as the AIS original message data, then connect the AIS original message data to the isolated serial signal distributor through the AIS external wiring terminal of the shipborne VDR signal machine, and then convert it into an Ethernet signal through the serial server via the RS485 serial port and transmit it to the industrial-grade tablet PC through the switch. The industrial-grade tablet PC parses the AIS original message data to extract the AIS navigation dynamic data and AIS static data.

6. A ship auxiliary berthing and unberthing system based on AIS, characterized in that, It includes an AIS data acquisition and parsing module, a left and right projection point coordinate calculation module, a ship contour model construction module, an isometric line construction and normal and radial velocity calculation module, and an auxiliary berthing decision module connected in sequence. The AIS data acquisition and parsing module obtains the AIS original message data of the ship through the shipborne VDR signal machine, and then parses the AIS original message data to extract the AIS navigation dynamic data and AIS static data. The AIS navigation dynamic data includes the longitude and latitude coordinates of the GPS position points, the heading angle of the ship, the actual heading, and the actual speed; the AIS static data includes the bow length and the distances between the GPS position points and the left side, right side, bow and stern of the ship, which are used as the left side distance, right side distance, bow distance and stern distance respectively. The left and right projection point coordinate calculation module extends the intersection points from the GPS position point along the direction perpendicular to the longitudinal axis of the hull to the left and right edges respectively as the left and right projection points, calculates the first azimuth angle of the left projection point relative to the GPS position point and the second azimuth angle of the right projection point relative to the GPS position point according to the heading angle of the ship, calculates the longitude and latitude coordinates of the left projection point according to the longitude and latitude coordinates of the GPS position point, the first azimuth angle and the left distance, and calculates the longitude and latitude coordinates of the right projection point according to the longitude and latitude coordinates of the GPS position point, the second azimuth angle and the right distance; The ship contour model construction module constructs a rectangle with the smallest area that completely encloses the overall contour of the ship as the circumscribed quadrilateral of the ship based on the bow vertex, left vertex, right vertex, left stern vertex and right stern vertex of the ship; based on the calculated longitude and latitude coordinates of the left and right projection points, the heading angle of the ship, the bow distance, the stern distance and the bow length, and according to the calculation principle of the longitude and latitude coordinates in the left and right projection point coordinate calculation module, calculates the longitude and latitude coordinates of the left front vertex, right front vertex, left vertex, right vertex, left stern vertex and right stern vertex of the circumscribed quadrilateral of the ship associated with the left and right projection points respectively; and calculates the longitude and latitude coordinates of the bow vertex of the ship according to the longitude and latitude coordinates of the left front vertex and right front vertex of the circumscribed quadrilateral of the ship; and then constructs the ship contour model based on the longitude and latitude coordinates of the bow vertex, left vertex, right vertex, left stern vertex and right stern vertex of the ship; The isometric line construction and normal and radial velocity calculation module constructs circumscribed rectangular frames concentric and coaxial with the ship contour model at regular intervals in the direction from near to far from the constructed ship contour model on the basis of the constructed ship contour model, generates multiple circumscribed rectangular frames as multiple groups of isometric lines around the ship contour model; and calculates the angle difference between the ship's heading and the actual course based on the actual speed, actual course and the heading angle of the ship; and calculates the normal velocity component and the radial velocity component respectively according to the angle difference and the actual speed; The auxiliary berthing and unberthing decision module displays the ship contour model, multiple groups of isometric lines around the ship contour model, the normal velocity component and the radial velocity component on the map in real time, extracts the ship-shore distance between the ship and the shore end in real time based on multiple groups of isometric lines on the map, establishes an auxiliary berthing and unberthing decision function based on the ship-shore distance, the normal velocity component and the radial velocity component, and assists the captain or pilot to judge whether the ship needs to decelerate according to the auxiliary berthing and unberthing decision function to complete the auxiliary berthing and unberthing decision of the ship.

7. The AIS-based ship auxiliary berthing and unberthing system according to claim 6, characterized in that, In the ship contour construction module, the calculation of the longitude and latitude coordinates of the left front vertex, right front vertex, left vertex, right vertex, left stern vertex and right stern vertex of the circumscribed quadrilateral of the ship associated with the left and right projection points respectively according to the calculation principle of the longitude and latitude coordinates in the left and right projection point coordinate calculation module specifically includes: Calculate the longitude and latitude coordinates of the right front vertex of the circumscribed quadrilateral of the ship associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the heading angle of the ship, and the bow distance; calculate the longitude and latitude coordinates of the right vertex of the ship associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the heading angle of the ship, the bow distance, and the length of the bow; calculate the third azimuth angle of the right rear vertex of the ship's stern relative to the right projection point based on the heading angle of the ship; and calculate the longitude and latitude coordinates of the right rear vertex of the ship's stern associated with the right projection point based on the longitude and latitude coordinates of the right projection point, the third azimuth angle, and the stern distance. Calculate the longitude and latitude coordinates of the left front vertex of the circumscribed quadrilateral of the ship associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the heading angle of the ship, and the bow distance; calculate the longitude and latitude coordinates of the left vertex of the ship associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the heading angle of the ship, the bow distance, and the length of the bow; calculate the fourth azimuth angle of the left rear vertex of the ship's stern relative to the left projection point based on the heading angle of the ship; and calculate the longitude and latitude coordinates of the left rear vertex of the ship's stern associated with the left projection point based on the longitude and latitude coordinates of the left projection point, the fourth azimuth angle, and the stern distance.

8. The AIS-based ship assisted berthing and unberthing system according to claim 6, characterized in that, In the isometric line construction and normal and radial velocity calculation module, the construction of the circumscribed rectangular frame specifically includes: Obtain the perpendicular distances from the GPS position point to the left and right frames of the circumscribed rectangular frame respectively as the first perpendicular distance and the second perpendicular distance, and calculate the longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the left frame of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the first azimuth angle, and the first perpendicular distance; and calculate the longitude and latitude coordinates of the perpendicular intersection point of the GPS position point and the right frame of the circumscribed rectangular frame based on the longitude and latitude coordinates of the GPS position point, the second azimuth angle, and the second perpendicular distance. Then calculate the longitude and latitude coordinates of the left front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the left frame, the heading angle of the ship, and the bow distance; calculate the longitude and latitude coordinates of the left rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the left frame, the heading angle of the ship, and the stern distance; calculate the longitude and latitude coordinates of the right front vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the right frame, the heading angle of the ship, and the bow distance; calculate the longitude and latitude coordinates of the right rear vertex of the circumscribed rectangular frame based on the longitude and latitude coordinates of the perpendicular intersection point of the right frame, the heading angle of the ship, and the stern distance, and then construct a circumscribed rectangular frame concentric and coaxial with the ship's contour model based on the longitude and latitude coordinates of the left front vertex, left rear vertex, right front vertex, and right rear vertex of the circumscribed rectangular frame.

9. The AIS-based ship assisted berthing and unberthing system according to claim 6, wherein, In the auxiliary berthing decision module, the judgment of whether the ship needs to decelerate by the captain or the pilot according to the auxiliary berthing decision function specifically includes: If the ship-shore distance is less than the first distance threshold and the normal velocity component or the radial velocity component is greater than the preset first velocity threshold, deceleration is required; if the ship-shore distance is greater than the first distance threshold and less than or equal to the second distance threshold, and the normal velocity component or the radial velocity component is greater than the preset second velocity threshold, deceleration is required; if the ship-shore distance is greater than the second distance threshold and less than or equal to the third distance threshold, and the normal velocity component or the radial velocity component is greater than the preset third velocity threshold, deceleration is required; if the ship-shore distance is greater than the third distance threshold and less than or equal to the fourth distance threshold, and the normal velocity component or the radial velocity component is greater than the preset fourth velocity threshold, deceleration is required.

10. The AIS-based ship auxiliary berthing and unberthing system according to any one of claims 6 to 9, characterized in that, The AIS data acquisition and parsing module is implemented based on the original shipborne VDR signal machine and the newly added serial signal distributor, serial server, switch, and industrial-grade tablet integrated machine installed on the ship. The AIS signal machine data of the ship is obtained through the shipborne VDR signal machine as the AIS original message data, and then the AIS original message data is connected to the serial signal distributor through the AIS external wiring terminal of the shipborne VDR signal machine, and then converted into an Ethernet signal through the RS485 serial port by the serial server and transmitted to the industrial-grade tablet integrated machine through the switch. The industrial-grade tablet integrated machine parses the AIS original message data to extract AIS navigation dynamic data and AIS static data; The left and right projection point coordinate calculation module, the ship contour model construction module, the equidistant line construction and normal and radial velocity calculation module, and the auxiliary berthing decision-making module are all integrated in the industrial-grade tablet integrated machine.

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