Method and device for evaluating credibility of ship navigation and PNT trusted terminal equipment

Abstract

The invention provides a credibility evaluation method and device for ship navigation and PNT trusted terminal equipment. The method comprises the following steps: acquiring navigation positioning information, a positioning interference probability and a positioning deception probability; determining the number of navigation positioning information sources and an information source positioning fusion mode according to the navigation positioning information; according to the number, the information source positioning fusion mode, the positioning interference probability and the positioning deception probability, determining the credibility level of navigation positioning; and outputting the credibility level. And reliable positioning information can be provided in a complex environment. According to the method, various data sources used in ship navigation and the deception and interference probabilities are combined, the navigation credibility is evaluated, the accuracy of credibility evaluation is improved, and then the ship navigation safety is improved.

Description

Technical Field

[0001] The present application relates to the field of marine navigation, and in particular to a method and apparatus for assessing the credibility of ship navigation, and a PNT trusted terminal device. Background Art

[0002] With the rapid development of automated shipping technology, ship navigation systems increasingly rely on data from the Global Navigation Satellite System (GNSS) and other sensors for precise positioning and path planning. However, GNSS signals are susceptible to external factors such as spoofing, jamming, and obstruction, posing potential risks to ship navigation safety. The reliability and trustworthiness of navigation systems are particularly important in complex or extreme environments.

[0003] Scientific reliability assessment methods enable real-time monitoring of navigation system reliability, providing early warning of potential risks and ensuring stable and safe navigation in complex environments. However, the reliability of data from different onboard sensors and other data sources varies significantly. For example, while an inertial navigation system (INS) provides reliable positioning information for a short period of time, its accuracy degrades over time due to accumulated errors. GNSS signals, while accurate, are susceptible to external environmental influences.

[0004] Therefore, how to effectively integrate various data sources and evaluate their credibility is a complex and challenging problem. Summary of the Invention

[0005] The present application provides a method and apparatus for assessing the credibility of ship navigation, and a PNT trusted terminal device, which are used to integrate various data sources used in ship navigation and assess the credibility of navigation.

[0006] In a first aspect, the present application provides a method for assessing the credibility of ship navigation, the method comprising:

[0007] Obtain navigation positioning information, the probability of positioning being interfered with, and the probability of positioning being deceived;

[0008] Determining the number of navigation and positioning information sources and the information source positioning fusion method based on the navigation and positioning information;

[0009] Determining a confidence level of navigation positioning according to the quantity, the information source positioning fusion mode, the probability of positioning being interfered with, and the probability of positioning being deceived;

[0010] The confidence level is output.

[0011] Optionally, determining the credibility level of navigation positioning according to the quantity, the information source positioning fusion mode, the positioning interference probability, and the positioning deception probability includes:

[0012] If the quantity is less than or equal to a preset quantity, determine that the trust level is a low trust level;

[0013] If the quantity is greater than the preset quantity, compare the positioning interference probability with a preset first interference probability;

[0014] If the positioning interference probability is greater than the first interference probability, determine that the trust level is a low trust level;

[0015] If the positioning interference probability is less than or equal to the first interference probability, compare the positioning spoofing probability with a preset first spoofing probability;

[0016] If the positioning spoofing probability is greater than the first spoofing probability, determine that the trust level is a low trust level;

[0017] If the positioning spoofing probability is less than or equal to the first spoofing probability, determine whether the information source positioning fusion method uses Kalman filtering;

[0018] If the information source positioning fusion method uses Kalman filtering, determine that the trust level is a high level;

[0019] If the information source positioning fusion method does not use Kalman filtering, determine that the trust level is a medium level.

[0020] Optionally, before obtaining the navigation positioning information, the positioning interference probability, and the positioning spoofing probability, the method further includes:

[0021] Obtain data of multiple navigation sensors, global navigation satellite GNSS data, and shore-based trusted service information;

[0022] Determine dead reckoning positioning based on the data of the multiple navigation sensors and preset initial positioning data;

[0023] Determine the navigation positioning information based on the GNSS data, the dead reckoning positioning, and the shore-based trusted service information.

[0024] Optionally, determining the navigation positioning information based on the GNSS data, the dead reckoning positioning, and the shore-based trusted service information includes:

[0025] Perform fusion positioning through the Kalman filtering algorithm based on the GNSS data, the dead reckoning positioning, and the shore-based trusted service information to obtain the navigation positioning information, where the shore-based trusted service information includes the credibility of measurement data.

[0026] Optionally, the method of obtaining the navigation and positioning information by fusing the GNSS data, the dead reckoning positioning, and the shore-based trusted service information through a Kalman filtering algorithm includes:

[0027] Determine a first weight of the measurement data in the shore-based trusted service information according to the credibility;

[0028] Determine a second weight of the GNSS data according to the positioning interference probability and the credibility;

[0029] Perform fusion positioning through a Kalman filtering algorithm according to the dead reckoning positioning and the corresponding third weight thereof, the measurement data in the shore-based trusted service information and the first weight, and the GNSS data and the second weight to obtain the navigation and positioning information.

[0030] Optionally, the third weight has a negative correlation with the cumulative duration, and the cumulative duration is the time interval between the current moment and the initial positioning moment of the initial positioning data.

[0031] Optionally, before the method determines the dead reckoning positioning through dead reckoning according to the multiple navigation sensor data and the preset initial positioning data, the method further includes:

[0032] Determine whether there is abnormal data in the multiple navigation sensor data, the global navigation satellite (GNSS) data, and the shore-based trusted service information respectively according to a preset data verification rule;

[0033] If there is the abnormal data, delete the abnormal data.

[0034] In a second aspect, the present application provides a trustworthiness evaluation device for ship navigation, and the device includes:

[0035] An acquisition module, configured to acquire navigation and positioning information, a positioning interference probability, and a positioning spoofing probability;

[0036] A determination module, configured to determine the number of navigation and positioning information sources and the information source positioning fusion method according to the navigation and positioning information;

[0037] A trustworthiness evaluation module, configured to determine the trust level of the navigation and positioning according to the number, the information source positioning fusion method, the positioning interference probability, and the positioning spoofing probability;

[0038] An output module, configured to output the trust level.

[0039] In a third aspect, the present application provides a PNT trusted terminal device, which is characterized by including: a memory, a processor;

[0040] The memory stores computer-executable instructions;

[0041] The processor executes the computer-executable instructions stored in the memory, such that the processor executes the method according to any one of the first aspect.

[0042] In a fourth aspect, the present application provides a computer-readable storage medium storing computer-executable instructions, which are used to implement the method according to any one of the first aspect when being executed by a processor.

[0043] In a fifth aspect, the present application provides a computer program product including a computer program, which implements the above first aspect and / or various possible implementation manners of the first aspect when being executed by a processor.

[0044] The present application provides a method, an apparatus and a PNT trusted terminal device for evaluating the credibility of ship navigation. The method includes: obtaining navigation and positioning information, positioning interference probability and positioning spoofing probability; determining the number of navigation and positioning information sources and the information source positioning fusion manner according to the navigation and positioning information; determining the credibility level of navigation and positioning according to the number, the information source positioning fusion manner, the positioning interference probability and the positioning spoofing probability; and outputting the credibility level. It is ensured that reliable positioning information can be provided in a complex environment. By the above method, combining various data sources used in ship navigation and the probabilities of being spoofed and interfered, the credibility of navigation is evaluated, the accuracy of credibility evaluation is improved, and further the navigation safety is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present application and, together with the specification, are used to explain the principles of the present application.

[0046] Figure 1 Schematic physical structure diagram of the PNT trusted terminal provided by the present application;

[0047] Figure 2 Schematic logical function diagram of the PNT trusted terminal provided by the present application;

[0048] Figure 3 Schematic flowchart of the method for evaluating the credibility of ship navigation provided by the present application Figure 1 ;

[0049] Figure 4 Schematic flowchart of the method for evaluating the credibility of ship navigation provided by the present application Figure 2 ;

[0050] Figure 5 General design flowchart of the PNT trusted terminal provided by the present application;

[0051] Figure 6 Schematic diagram of the process of obtaining shipborne navigation sensor information provided for this application;

[0052] Figure 7 Schematic diagram of the process for obtaining shore-based trusted service information provided for this application;

[0053] Figure 8 Schematic diagram of the fusion positioning function provided by this application;

[0054] Figure 9 A flow chart of the fusion positioning method provided in this application;

[0055] Figure 10 This is a schematic diagram of the structure of a ship navigation credibility assessment device provided by this application;

[0056] Figure 11 This is a schematic diagram of the structure of the PNT trusted terminal device provided in this application.

[0057] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0058] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0059] To ensure safe navigation of ships, it is crucial to evaluate the reliability of navigation systems. Reliability assessment is not just about checking whether positioning is accurate, but also involves a comprehensive assessment of the quality, stability, and reliability of different sensor data sources. Through scientific reliability assessment methods, the reliability of navigation systems can be monitored in real time, potential risks can be warned in advance, and ships can maintain stable and safe navigation in complex environments.

[0060] Current navigation systems rely heavily on GNSS signals, which are inherently susceptible to jamming, spoofing, or counterfeiting. When a navigation system relies on a single data source, such as GNSS, and that signal is attacked or jammed, positioning accuracy can be significantly reduced, or even completely lost.

[0061] In addition, the credibility of different sensors and data sources varies greatly. For example, an Inertial Navigation System (INS) provides reliable positioning information in a short period of time, but over time, due to cumulative error problems, the positioning accuracy will gradually decrease. While GNSS signals are accurate, they are easily affected by the external environment. Therefore, how to effectively integrate the credibility of various data sources and conduct reasonable evaluation is a complex and challenging problem.

[0062] In view of this, the present application proposes a method for evaluating the credibility of ship navigation, which determines the credibility level of navigation positioning by combining the number of navigation positioning information sources, the information source positioning fusion method, and the probability of positioning being interfered and deceived during the evaluation. The above method comprehensively evaluates the credibility of various data sources, and then makes a credibility evaluation to improve the evaluation accuracy.

[0063] The method of the present application is applied to the shipborne PNT credible terminal device. Through in-depth analysis of the service requirements of the PNT credible terminal, the terminal is divided into different functions, and each function is then introduced in detail. Subsequently, the design is carried out separately from the physical structure and the logical function. The physical structure introduces the types of hardware that need to be connected externally to the PNT credible terminal, and the logical function introduces the functional logical relationship inside the shipborne integrated PNT credible terminal. Then, the data flow of the shipborne integrated PNT credible terminal is designed, and the overall process of the credible terminal, the process of obtaining shipborne navigation sensor information, the process of obtaining shore-based credible service information, the credibility evaluation process, the interference detection process, the spoofing detection process, the fusion positioning process, the status monitoring process, the alarm process, the output process are introduced in detail, and the format of the transmitted data is also introduced. Finally, the overall architecture design of the software program is carried out, and the functional software coding ideas of each module for reference are given.

[0064] The following uses specific embodiments to elaborate in detail on the technical solution of the present application and how the technical solution of the present application solves the above technical problems. These several specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0065] Figure 1 is a schematic diagram of the physical structure of the PNT credible terminal provided by the present application, as Figure 1As shown in the figure, the shipborne sensors connected to the PNT trusted terminal include a compass, a log, an echo sounder, GNSS, and a wind and speed sensor. Eastward and northward speed information, range information, ship's heading information, water depth information, positioning information, and wind and speed information can be obtained from these sensors. The shore-based trusted service receiver connected to the PNT trusted terminal includes RBN-DGNSS, CORS, AIS, VDES, and NAVTEX, which can provide differential positioning information, positioning information, shore-based trusted service information, maritime safety information, etc.

[0066] The functions of each sensor are introduced as follows:

[0067] (1) GNSS-related equipment: Obtain positioning information. The GNSS signal receiving antenna is used to receive and transmit satellite signals to the aircraft body; the high-sensitivity GNSS receiver is used to receive, process, and demodulate signals; the radio frequency circuit supports signals of GPS, BDS, Galileo, and GLONASS satellite systems; the antenna transceiver cable is used to connect the GNSS antenna and is responsible for transmitting PNT signals.

[0068] (2) Echo sounder: Used to detect and return water depth information.

[0069] (3) Compass: Measure the ship's heading information.

[0070] (4) Log: Measure eastward and northward speed information and calculate it into range information through the speed calculation device in the log.

[0071] (5) Wind and speed sensor: Measure and record wind speed and direction data.

[0072] (5) RBN-DGNSS receiver: Receive differential positioning information and calculate positioning information through built-in embedded software.

[0073] (6) AIS receiver: Used to receive shore-based trusted service information.

[0074] (7) VDES receiver: Used to receive shore-based trusted service information.

[0075] (8) NAVTEX receiver: Used to receive maritime safety information sent from the shore.

[0076] (9) CORS receiver: Used to receive positioning and navigation assistance data sent from the shore.

[0077] Figure 2 It is the schematic diagram of the logical function of the PNT trusted terminal provided by this application, as Figure 2As shown in the figure, the design scheme of the shipborne integrated PNT trusted terminal mainly includes eight major functions: data input function, data output function, main control, status monitoring, trustworthiness evaluation, interference detection function, spoofing detection function, and integrated positioning function.

[0078] Referring to Figure 2 , the internal interfaces of the PNT trusted terminal are as follows:

[0079] (1) Interface (②) between the main control unit and the data input function: Based on C++ / object data format, including time information, longitude and latitude information, differential positioning information, ship's heading information, east-north velocity information, range information, water depth information, shore-based trusted service information, and maritime safety communication information.

[0080] (2) Interface (③) between the main control unit and the status monitoring function: The main control unit sends a status monitoring start request and the working conditions of each module to the status monitoring function; the status monitoring function returns the working status results of each module to the main control unit.

[0081] (3) Interface (④) between the main control unit and the alarm function: The main control unit sends the operating status of each module to the alarm function, and the alarm module returns whether an alarm is needed and the corresponding number of the alarm module to the main control unit.

[0082] (4) Interface (⑤) between the main control unit and the trustworthiness evaluation function: The main control module sends the input shipborne navigation information, shore-based trusted service information, integrated positioning information, and the probability information of being spoofed and interfered returned by the interference detection module and the spoofing detection module to the trustworthiness evaluation function, and the trustworthiness evaluation function returns the trustworthiness evaluation level result and whether it is trustworthy for the current ship's sailing sea area status.

[0083] (5) Interface (⑥) between the main control unit and the interference detection function: The main control unit sends the input data information and the primary positioning information returned by the integrated positioning module to the interference detection function, and the interference detection function returns the probability of being interfered and the working conditions of the module to the main control unit.

[0084] (6) Interface (⑦) between the main control unit and the spoofing detection function: The main control unit sends the input data information, the primary positioning information and the integrated positioning information returned by the integrated positioning module to the spoofing detection function, and the spoofing detection function returns the probability of being spoofed and the working conditions of the module to the main control unit.

[0085] (7) Interface (⑧) between the main control unit and the integrated positioning function: The main control unit sends the shipborne navigation sensor information, shore-based trusted service information, interference situation, and spoofing situation to the positioning function, and the positioning function returns the single-sensor positioning result, integrated positioning result, trusted integrated positioning result, and the working conditions of the functional module to the main control unit.

[0086] Interface (⑨) between the main control unit and the output function: Based on C++ / object data format, specifically including: alarm status, alarm reason information, positioning result coordinates, credibility level, probability of being interfered, probability of being spoofed, messages sent by shore-based trusted services, data rationality sent by on-board navigation sensor modules, working status of each module, and whether the current navigation status is credible.

[0087] Taking the above PNT trusted terminal as the execution subject, the credibility assessment function is introduced below.

[0088] Figure 3 Flow schematic of the credibility assessment method for ship navigation provided by this application Figure 1 as Figure 3 shown, including the following steps:

[0089] S101. Obtain navigation and positioning information, probability of positioning being interfered, and probability of positioning being spoofed.

[0090] Obtain the above-mentioned various on-board navigation sensors (including GNSS data) and shore-based trusted service information.

[0091] Evaluate the risk of whether GNSS positioning information is interfered based on GNSS data. For example, GNSS signals may be interfered or blocked (such as signal reflection, signal noise, malicious interference, etc.), resulting in abnormal data, including lost data or out-of-range data, or even jumping. According to the proportion of abnormal data, the probability of being interfered can be determined. In addition, evaluate whether the GNSS signal is spoofed (such as forged satellite signals or spoofing attacks). This probability reflects the possibility of the navigation system being subjected to signal spoofing, which can be evaluated by detecting the authenticity and integrity of GNSS signals, or by comparing GNSS data with navigation and positioning information, and using the navigation and positioning information as a benchmark to evaluate the probability of the GNSS signal being spoofed.

[0092] For navigation and positioning information, it is the navigation and positioning determined by the PNT trusted terminal based on the fusion of GNSS data, shore-based trusted service information, and shipborne track inference information. The track inference category is determined based on various navigation sensors and the preset initial positioning.

[0093] S102. According to the navigation and positioning information, determine the number of navigation and positioning information sources and the information source positioning fusion method.

[0094] The navigation and positioning information sources include three categories: GNSS data, shore-based trusted service information, and ship dead reckoning. The calculation of ship navigation trajectory dead reckoning can use the following information sources: the heading information measured by a compass sensor, the speed and mileage information measured by a log, and the wind speed and direction information measured by an anemometer. The fusion methods include Kalman filtering, averaging, particle filtering, etc.

[0095] Based on the navigation and positioning information, identify the number of information sources used for positioning and the information source fusion method.

[0096] S103. Determine the trust level of navigation and positioning according to the number, information source positioning fusion method, positioning interference probability, and positioning spoofing probability.

[0097] The PNT trusted terminal evaluates the capabilities of the current navigation system based on the number of positioning information sources used and their fusion method. If the system uses multiple high-precision information sources, its credibility is usually high; while if the number of information sources is small or the fusion method is unreasonable, the credibility may be low. In addition to considering the number of positioning information sources and the fusion method, it is also necessary to consider the positioning interference probability and spoofing probability to comprehensively obtain the trust level.

[0098] In a specific implementation, a preset number of information sources can be set. If the number of information sources is less than or equal to the preset number, it is determined that the number of positioning information sources is small and the credibility is low. For different fusion methods, different credibility levels can also be set. For example, when using Kalman filtering, it can be set to a high credibility level, while for the averaging fusion method, it can be set to a medium credibility level. For the positioning interference probability and positioning spoofing probability, if either probability exceeds the preset probability value, the credibility is low. For the credibility levels of the number of information sources, the information source positioning fusion method, the positioning interference probability, and the positioning spoofing probability, the lowest credibility level is used as the final credibility level.

[0099] S104. Output the trust level.

[0100] In one implementation, the trust level of the current navigation is displayed on the navigation display interface of the ship.

[0101] This embodiment provides a method for evaluating the credibility of ship navigation, which includes: obtaining navigation and positioning information, positioning interference probability, and positioning spoofing probability; determining the number of navigation and positioning information sources and the information source positioning fusion method according to the navigation and positioning information; determining the credibility level of navigation and positioning according to the number, information source positioning fusion method, positioning interference probability, and positioning spoofing probability; and outputting the credibility level. Ensure that reliable positioning information can be provided in a complex environment. Through the above method, combining various data sources used in ship navigation, as well as the probabilities of spoofing and interference, the credibility of navigation is evaluated, the accuracy of credibility evaluation is improved, and thus the navigation safety is improved.

[0102] Figure 4 It is a schematic flow of the method for evaluating the credibility of ship navigation provided by this application Figure 2 As Figure 4 shown, after the credibility evaluation module is started, first check whether the credibility evaluation module is equipped on the ship and whether the module is started normally. If not, the credibility is N (untrusted level).

[0103] If so, receive valid shipborne navigation sensor data, valid shore-based trusted service data, interference probability, spoofing probability, and trusted fusion positioning information, and then check whether the number of information sources in the positioning information is less than or equal to the preset number. If so, determine that the credibility level is the low credibility level and the credibility is L.

[0104] If the number is greater than the preset number, compare the positioning interference probability with the preset first interference probability;

[0105] If the positioning interference probability is greater than the first interference probability, determine that the credibility level is the low credibility level and the credibility is L;

[0106] If the positioning interference probability is less than or equal to the first interference probability, compare the positioning spoofing probability with the preset first spoofing probability;

[0107] If the positioning spoofing probability is greater than the first spoofing probability, determine that the credibility level is the low credibility level and the credibility is L;

[0108] If the positioning spoofing probability is less than or equal to the first spoofing probability, determine whether the Kalman filter is used in the information source positioning fusion method;

[0109] If the Kalman filter is used in the information source positioning fusion method, determine that the credibility level is the high level and the credibility is H;

[0110] If the Kalman filter is not used in the information source positioning fusion method, determine that the credibility level is the medium level and the credibility is M.

[0111] Optionally, obtain the current operating environment of the ship, where the current operating environment includes weather conditions and equipment operating status; determine whether the current operating environment is trustworthy based on the current operating environment, and update the trust level. If the weather conditions are poor (such as strong winds, heavy rain, thick fog, or extreme climates) or the equipment fails, it may cause the signal of the positioning system to be lost or the error to increase. For example, GNSS signals may be affected by shielding, and radar and optical sensors may not be able to provide accurate data in low visibility conditions, and the trust level should be reduced.

[0112] The overall functions of the PNT trustworthy terminal and the specific function implementations of each module are introduced below.

[0113] Figure 5 This is the overall design flow chart of the PNT trustworthy terminal provided by this application, as Figure 5 shown. After the PNT trustworthy terminal is started, it obtains information from on-board navigation sensors and shore-based trustworthy service data receivers. Then, the data is time-unified and space-unified by the space-time unification module. The unified data is sent to the interference detection module to calculate the interference probability and sent to the spoofing detection module to calculate the spoofing probability. The fusion positioning module receives the modified on-board navigation sensor data, shore-based trustworthy service data, interference detection module data, and spoofing detection module data from the space-time unification module, and outputs the fused navigation and positioning information. Subsequently, the trust evaluation module receives the navigation and positioning information from the fusion positioning module, the interference probability from the interference detection module, and the spoofing probability from the spoofing detection module, and performs trust level evaluation. During this period, the status monitoring module monitors the real-time module operating status of all other modules including the alarm module, and the alarm module receives information from the interference detection module, spoofing detection module, and status detection module. Finally, the trustworthy positioning information, alarm information, trustworthiness level information, whether the current operating environment is trustworthy, the interference probability, the spoofing probability, the status information of each module, and the shore-based trustworthy service message are visually output, and the message is encapsulated and stored, and alarms are issued for existing faults or untrustworthy events.

[0114] The data stream types and protocol standard formats of the PNT trustworthy terminal are shown in Table 1.

[0115] Table 1 Overall design data table of the on-board integrated PNT trustworthy terminal

[0116]

[0117] Figure 6 This is the schematic diagram of the acquisition process of on-board navigation sensor information provided by this application, as Figure 6As shown in the figure, after the on-board navigation sensor information acquisition module is started, it first collects on-board navigation sensor data. Through validity verification, if the data is normal, the message information is extracted and the message is parsed. Then, through authenticity verification, if the data is normal, the data is output to the corresponding class, and for abnormal data, it is written into the data verification class (for the design of the class, refer to the software system design module). The on-board navigation sensor data includes the measurement data of RBN-DGNSS, GNSS, compass, log, and echo sounder.

[0118] The required data stream types and protocol standard formats are as follows:

[0119] Table 2 On-board Navigation Sensor Information Acquisition Data Interface Table

[0120]

[0121] Figure 7 The following is a schematic diagram of the acquisition process of shore-based trusted service information provided by this application. As Figure 7 shown, after the shore-based trusted service information acquisition module is started, it first collects the data of shore-based trusted service information. Then, it performs validity verification. If there are abnormalities, the abnormal data is excluded. After that, information parsing is carried out, and finally, the shore-based trusted service information class data is returned to the main module.

[0122] The required data stream types and protocol standard formats are as follows:

[0123] Table 3 Shore-based Trusted Service Information Acquisition Data Interface Table

[0124]

[0125] Next, the function of integrated positioning will be introduced.

[0126] Figure 8 The following is a schematic diagram of the integrated positioning function provided by this application. As Figure 8 shown, after the integrated positioning module is started, it first receives the on-board navigation sensor class data and the shore-based trusted service class data. Then, it uses the information of sensors such as compass, log, and wind direction and speed sensor to perform dead reckoning positioning and return the result. Next, it uses the auxiliary positioning information of GNSS, dead reckoning, and shore-based trusted service class information for integrated positioning and returns the result. Finally, referring to the interference situation and spoofing situation, it uses the trusted sensor information for trusted integrated positioning and returns the final trusted integrated positioning result.

[0127] The required data stream types and protocol standard formats are as follows:

[0128] Table 4 Integrated Positioning Module Data Interface Table

[0129]

[0130] The following introduces how to perform integrated positioning specifically.

[0131] Figure 9 It is a schematic flow diagram of the integrated positioning method provided by this application. As Figure 9 shown, obtain data from multiple navigation sensors, Global Navigation Satellite System (GNSS) data, and shore-based trusted service information;

[0132] Step 1: Perform dead reckoning. Dead reckoning needs to determine the dead reckoning type of positioning based on data from multiple navigation sensors and preset initial positioning data. This initial positioning data is the positioning information of the ship at the previous fixed moment in the GNSS data. Through the trajectory calculation of integrated navigation, the sensor fusion positioning type can be obtained.

[0133] In one implementation, based on ship sensor data (such as accelerometers, gyroscopes, heading sensors, etc.) and preset initial positioning data, the position of the ship is calculated by integrating the motion model of the ship. This method uses the ship kinematic model to combine data from multiple navigation sensors for position estimation.

[0134] Step 2: Determine the navigation positioning information according to the GNSS data, dead reckoning type of positioning, and shore-based trusted service information.

[0135] Specifically, according to the GNSS data, dead reckoning type of positioning, and shore-based trusted service information, integrated positioning is performed through the Kalman filter algorithm to obtain the navigation positioning information. The shore-based trusted service information includes the credibility of measurement data.

[0136] The Kalman filter is a recursive algorithm that can continuously update the prior estimate through iteration and fuse data from different sensors to obtain more accurate positioning information. This algorithm models the uncertainty of sensor data and measurement noise to optimize the fusion of multi-source information.

[0137] The data input into the Kalman filter includes: GNSS data, which provides positioning information at the current timestamp and may be affected by the environment. The dead reckoning result based on inertial sensors, etc., is applicable to continuous positioning when GNSS fails but may have cumulative errors. Data from shore-based stations mainly provides information such as signal quality and the credibility of measurement data. Credibility assessment helps to judge the importance and reliability of different information sources, thereby adjusting the weights of the Kalman filter.

[0138] The Kalman filter processing procedure is as follows: Based on dead reckoning positioning (such as through an inertial navigation system), the position is predicted to forecast the position of the ship at the next moment. At each moment, GNSS data (if the data is normal) and shore-based trusted service information are used to correct the predicted position, and the weights of dead reckoning positioning, GNSS weights, and shore-based trusted service information are adjusted through credibility. With the continuous addition of new GNSS data and shore-based trusted service information, the Kalman filter will repeatedly adjust the filtering results to improve the accuracy and credibility of the final positioning.

[0139] In a specific implementation method for determining navigation positioning through the Kalman filter, the following steps are included:

[0140] 1. Determine the first weight of the measurement data in the shore-based trusted service information according to the credibility.

[0141] Determining the first weight of the shore-based trusted service according to the credibility can ensure that more reliable data obtains a higher weight, thereby improving the accuracy of the positioning result. The specific determination method can be determined through a preset mapping relationship.

[0142] 2. Determine the second weight of the GNSS data according to the positioning interference probability and the credibility.

[0143] GNSS data is usually the main source of positioning, but it may be interfered with, especially in an environment with signal occlusion. Therefore, by combining the positioning interference probability and the credibility to determine the second weight, the weight of the GNSS data can be dynamically adjusted to ensure greater reliance on GNSS when the GNSS signal is good, and to reduce the influence of GNSS data when the signal interference is large, improving the stability of the fusion result.

[0144] 3. Perform fusion positioning through the Kalman filter algorithm according to the dead reckoning positioning and the corresponding third weight, the measurement data and the first weight in the shore-based trusted service information, and the GNSS data and the second weight to obtain the navigation positioning information.

[0145] In the Kalman filtering algorithm, the weights of each data source are crucial. Especially when dealing with multi-source information, the weights determine the contribution of each sensor's information in the fusion process. The third weight is the weight for dead reckoning positioning, which depends on the performance of the Inertial Navigation System (INS) or other sensors in continuous positioning. In the absence of GNSS signals, dead reckoning can provide effective relative position information, but there may be cumulative errors. Therefore, the third weight can be set such that the longer the time interval from the initial positioning moment to the current time (i.e., the longer the cumulative duration), the smaller the third weight, showing a negative correlation. The downward trend of the third weight with the cumulative duration can be set as needed. Kalman filtering optimizes the final positioning by combining the above multiple weights. The uncertainty and credibility of each data source (dead reckoning, shore-based trusted service information, and GNSS data) are weighted and fused through the Kalman filter, and the final output positioning information combines the advantages of all data sources, improving the accuracy and robustness of positioning.

[0146] This method of Kalman filter fusion by setting weights and combining multi-source information (GNSS, shore-based trusted service information, dead reckoning positioning) can dynamically adjust the weights according to the credibility of different data sources, thereby optimizing the final navigation positioning result. In practical applications, it can effectively improve the adaptability of the system to various complex environments (such as signal occlusion or interference).

[0147] Before the above Kalman filtering algorithm fusion, if there are data anomalies, such as not meeting the protocol format requirements or the authenticity detection not meeting the requirements, some information sources need to be discarded. For example, certain sensor failures result in abnormal collected data. The PNT trusted terminal will record the number of information sources input into the Kalman filtering algorithm for subsequent credibility assessment.

[0148] Figure 10 The structural schematic diagram of a credibility assessment device for ship navigation provided by this application is as Figure 10 shown. The credibility assessment device 40 for ship navigation includes:

[0149] An acquisition module 401, configured to acquire navigation positioning information, positioning interference probability, and positioning spoofing probability;

[0150] A determination module 402, configured to determine the number of navigation positioning information sources and the information source positioning fusion method according to the navigation positioning information;

[0151] A credibility assessment module 403, configured to determine the credibility level of navigation positioning according to the number, the information source positioning fusion method, the positioning interference probability, and the positioning spoofing probability;

[0152] An output module 404, configured to output the credibility level.

[0153] Optionally, the credibility evaluation module 403 is specifically configured to:

[0154] If the quantity is less than or equal to a preset quantity, determine that the credibility level is a low credibility level;

[0155] If the quantity is greater than the preset quantity, compare the positioning interference probability with a preset first interference probability;

[0156] If the positioning interference probability is greater than the first interference probability, determine that the credibility level is a low credibility level;

[0157] If the positioning interference probability is less than or equal to the first interference probability, compare the positioning deception probability with a preset first deception probability;

[0158] If the positioning deception probability is greater than the first deception probability, determine that the credibility level is a low credibility level;

[0159] If the positioning deception probability is less than or equal to the first deception probability, determine whether the Kalman filter is used in the information source positioning fusion method;

[0160] If the Kalman filter is used in the information source positioning fusion method, determine that the credibility level is a high level;

[0161] If the Kalman filter is not used in the information source positioning fusion method, determine that the credibility level is a medium level.

[0162] Optionally, the obtaining module 401 is further configured to:

[0163] Obtain multiple navigation sensor data, global navigation satellite GNSS data, and shore-based trusted service information;

[0164] Correspondingly, the determining module 402 is further configured to:

[0165] Determine the dead reckoning type positioning according to the multiple navigation sensor data and the preset initial positioning data;

[0166] Determine the navigation positioning information according to the GNSS data, the dead reckoning type positioning, and the shore-based trusted service information.

[0167] Optionally, the determining module 402 is specifically configured to:

[0168] Perform fusion positioning through the Kalman filter algorithm according to the GNSS data, the dead reckoning type positioning, and the shore-based trusted service information to obtain the navigation positioning information, where the shore-based trusted service information includes the credibility of the measurement type data.

[0169] Optionally, the determining module 402 is specifically configured to:

[0170] Determine a first weight of the measurement data in the shore-based trusted service information according to the credibility;

[0171] Determine a second weight of the GNSS data according to the positioning interference probability and the credibility;

[0172] Perform fusion positioning through the Kalman filtering algorithm according to the dead reckoning positioning and the corresponding third weight of the dead reckoning positioning, the measurement data in the shore-based trusted service information and the first weight, and the GNSS data and the second weight to obtain the navigation positioning information.

[0173] Optionally, the third weight is negatively correlated with the cumulative duration, and the cumulative duration is the time interval between the current moment and the initial positioning moment of the initial positioning data.

[0174] Optionally, the obtaining module 401 is further configured to:

[0175] Determine whether there is abnormal data in multiple navigation sensor data, global navigation satellite GNSS data, and shore-based trusted service information respectively according to a preset data verification rule;

[0176] If there is the abnormal data, delete the abnormal data.

[0177] Optionally, the credibility evaluation module 403 is further configured to:

[0178] Obtain the current operating environment of the ship, where the current operating environment includes weather conditions and equipment operating status;

[0179] Update the credibility level according to the current operating environment.

[0180] The credibility evaluation device for ship navigation provided in this embodiment can execute the method provided in the above method embodiment, and its implementation principle and technical effects are similar, which will not be elaborated here in this embodiment.

[0181] Figure 11 It is a schematic structural diagram of the PNT trusted terminal device provided by this application. As Figure 11 shown, the device 50 provided in this embodiment includes: at least one processor 501 and a memory 502. Optionally, the device 50 further includes a communication component 503. Among them, the processor 501, the memory 502, and the communication component 503 are connected through a bus 504.

[0182] In a specific implementation process, at least one processor 501 executes computer-executable instructions stored in a memory 502, enabling the at least one processor 501 to execute the above-described method.

[0183] For the specific implementation process of the processor 501, reference may be made to the above method embodiments. Their implementation principles and technical effects are similar, and will not be elaborated here in this embodiment.

[0184] The PNT trusted terminal device further includes a display for visually displaying trusted-related information. The PNT trusted terminal device also stores an electronic chart for visually displaying sea routes, providing sea chart information query operations for any point on the sea chart, and providing a friendly user interaction display interface.

[0185] For the memory 502, the storage space size requirement for normal navigation ship data in the terminal is between 200 GB and 2 TB. Therefore, this design solution also requires the storage space size in the terminal to be between 200 GB and 2 TB. And it is required that this storage space stores ship status, navigation records, configuration and setting information, and parsed shore-based trusted service received information, etc. Among these, the storage space allocation requirement for status information occupies the largest space, followed by navigation records. The occupied space of configuration and setting information is smaller than that of ship status information. Therefore, 40% of the storage space is allocated to ship status, 30% to navigation records, 20% to shore-based trusted service received information, and 10% to configuration and setting information. When a certain type of information is full, the oldest stored information is deleted to store new information of the same type. Among them, ship status and navigation records need to save data such as longitude and latitude, UTC time, total number of visible satellites, satellite PRN code number, satellite signal-to-noise ratio, course over ground, speed over ground, horizontal movement speed, heading azimuth, turning rate, speed, voyage, water depth, wind speed, and wind direction after parsing the telegrams of each sensor. Configuration and setting information needs to configure storage format information and select a data transmission rate among 38400 / 19200 / 9600 bps.

[0186] In the above embodiments, it should be understood that the processor may be a central processing unit (English: Central Processing Unit, abbreviated: CPU), or may also be other general-purpose processors, digital signal processors (English: Digital Signal Processor, abbreviated: DSP), application specific integrated circuits (English: Application Specific Integrated Circuit, abbreviated: ASIC), etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor.

[0187] The memory may include a random access memory (RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0188] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the buses in the drawings of this application are not limited to only one bus or one type of bus.

[0189] This application also provides a computer program product, including a computer program which, when executed by a processor, implements the above method.

[0190] This application also provides a ship that can execute the method of the above embodiment.

[0191] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above method.

[0192] The above-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic disk, or an optical disk. The readable storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0193] An exemplary readable storage medium is coupled to the processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in a device.

[0194] The division of units is merely a logical function division. In actual implementation, there may be other division methods. For example, multiple types of units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed among each other can be through some interfaces. The indirect couplings or communication connections of devices or units can be in electrical, mechanical or other forms.

[0195] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple types of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0196] In addition, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0197] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in each embodiment of the present invention. And the aforementioned storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks or optical disks and other various media that can store program codes.

[0198] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When this program is executed, it executes the steps including the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disks or optical disks and other various media that can store program codes.

[0199] Finally, it should be noted that: after considering the specification and practicing the invention disclosed herein, those skilled in the art will readily conceive of other embodiments of the present invention. The present invention is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field not disclosed by the present invention. It is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A method for evaluating the credibility of ship navigation, characterized in that The method includes: Obtaining navigation positioning information, positioning interference probability, and positioning spoofing probability; Determining the number of navigation positioning information sources and the information source positioning fusion method according to the navigation positioning information; Determining the credibility level of navigation positioning according to the number, the information source positioning fusion method, the positioning interference probability, and the positioning spoofing probability; Outputting the credibility level.

2. The method according to claim 1, wherein The determining the credibility level of navigation positioning according to the number, the information source positioning fusion method, the positioning interference probability, and the positioning spoofing probability includes: If the number is less than or equal to a preset number, determining that the credibility level is a low credibility level; If the number is greater than the preset number, comparing the positioning interference probability with a preset first interference probability; If the positioning interference probability is greater than the first interference probability, determining that the credibility level is a low credibility level; If the positioning interference probability is less than or equal to the first interference probability, comparing the positioning spoofing probability with a preset first spoofing probability; If the positioning spoofing probability is greater than the first spoofing probability, determining that the credibility level is a low credibility level; If the positioning spoofing probability is less than or equal to the first spoofing probability, determining whether the Kalman filter is used in the information source positioning fusion method; If the Kalman filter is used in the information source positioning fusion method, determining that the credibility level is a high level; If the Kalman filter is not used in the information source positioning fusion method, determining that the credibility level is a medium level.

3. The method according to claim 1 or 2, characterized in that, Before obtaining the navigation positioning information, the positioning interference probability, and the positioning spoofing probability, the method further includes: Obtaining multiple navigation sensor data, global navigation satellite GNSS data, and shore-based trusted service information; Determining dead reckoning positioning according to the multiple navigation sensor data and preset initial positioning data; Determining the navigation positioning information according to the GNSS data, the dead reckoning positioning, and the shore-based trusted service information.

4. The method according to claim 3, characterized in that The determining the navigation positioning information according to the GNSS data, the dead reckoning positioning, and the shore-based trusted service information includes: Performing fusion positioning through the Kalman filter algorithm according to the GNSS data, the dead reckoning positioning, and the shore-based trusted service information to obtain the navigation positioning information, where the shore-based trusted service information includes the credibility of measurement data.

5. The method according to claim 4, characterized in that The performing fusion positioning through the Kalman filter algorithm according to the GNSS data, the dead reckoning positioning, and the shore-based trusted service information to obtain the navigation positioning information includes: Determining a first weight of the measurement data in the shore-based trusted service information according to the credibility; Determining a second weight of the GNSS data according to the positioning interference probability and the credibility; Performing fusion positioning through the Kalman filter algorithm according to the dead reckoning positioning and the corresponding third weight thereof, the measurement data in the shore-based trusted service information and the first weight, and the GNSS data and the second weight to obtain the navigation positioning information.

6. The method according to claim 5, wherein The third weight has a negative correlation with the cumulative duration, and the cumulative duration is the time interval between the current moment and the initial positioning moment of the initial positioning data.

7. The method according to claim 3, wherein Before determining the dead reckoning type positioning by dead reckoning according to the multiple navigation sensor data and the preset initial positioning data, the method further includes: According to the preset data verification rules, respectively determine whether there is abnormal data in the multiple navigation sensor data, the global navigation satellite GNSS data, and the shore-based trusted service information; If there is the abnormal data, delete the abnormal data.

8. A credibility evaluation device for ship navigation, characterized in that, The device includes: An acquisition module, configured to acquire navigation positioning information, positioning interference probability, and positioning spoofing probability; A determination module, configured to determine the number of navigation positioning information sources and the information source positioning fusion method according to the navigation positioning information; A credibility evaluation module, configured to determine the credibility level of the navigation positioning according to the number, the information source positioning fusion method, the positioning interference probability, and the positioning spoofing probability; An output module, configured to output the credibility level.

9. A PNT trusted terminal device, characterized in that, Including: A memory, a processor; The memory stores computer execution instructions; The processor executes the computer execution instructions stored in the memory, so that the processor executes the method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that Computer execution instructions are stored in the computer-readable storage medium, and when the computer execution instructions are executed by a processor, they are used to implement the method according to any one of claims 1-7.

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