Shipborne intelligent navigation method based on satellite and inertial combination technology

Abstract

The invention discloses a shipborne intelligent navigation method based on a satellite-inertial combination technology. The method comprises the steps of system initialization, navigation in a satellite signal normal state, navigation in a satellite signal disconnection state, navigation in a satellite signal denial environment, navigation mode adaptive switching and similar route library dynamic updating. The invention relates to the technical field of intelligent navigation. According to the ship-borne intelligent navigation method based on the satellite-inertial combination technology, all-weather and high-reliability navigation of a ship in different signal environments is realized through information fusion of multi-source sensors such as a high-precision GNSS receiver, an optical fiber gyroscope, an MEMS inertial unit, an underwater acoustic velocimeter and a geomagnetic module in combination with intelligent matching of a similar route library. The method is particularly suitable for ship intelligent navigation in satellite signal disconnection and denial environments, and has the characteristics of strong anti-interference capability, high intelligent degree and strong self-learning capability.

Description

Technical Field

[0001] The present invention relates to the field of intelligent navigation technology, and in particular to a shipborne intelligent navigation method based on satellite-inertial combined technology. Background Art

[0002] With the rapid development of maritime transportation and marine resource development, the requirements for the accuracy and reliability of ship navigation technology are constantly increasing. Currently, the Global Navigation Satellite System (GNSS) is widely used for ship navigation, but relying solely on GNSS presents issues such as signal susceptibility to interference and obstruction. In particular, in scenarios such as electronic warfare environments, urban canyons, and complex sea areas, GNSS signals can be interfered with or even completely fail, resulting in reduced positioning accuracy and even navigation interruption.

[0003] Traditional inertial navigation systems (INS) offer advantages such as strong autonomy and high short-term accuracy, but they also suffer from cumulative errors. Hydroacoustic velocimeters provide underwater velocity information, while geomagnetic navigation is less susceptible to interference from external magnetic fields and offers good stealth. However, no single navigation method can meet the requirements for all-weather, high-precision navigation of ships.

[0004] Therefore, a shipborne intelligent navigation method based on satellite-inertial combined technology is proposed to solve the existing problems. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a shipborne intelligent navigation method based on satellite-inertial combined technology, which solves the problem that traditional navigation methods are too single and cannot meet the all-weather, high-precision navigation needs of ships.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a shipborne intelligent navigation method based on satellite-inertial combined technology, specifically comprising the following steps:

[0007] S1. System initialization: Start the ship's navigation system, including a high-precision GNSS receiver, fiber optic gyroscope, MEMS inertial unit, hydroacoustic velocimeter, geomagnetic module, and a similar route library;

[0008] S2. Navigation under normal satellite signal conditions: Use high-precision GNSS receivers to obtain centimeter-level positioning information, and obtain ship attitude information through the fusion of fiber optic gyroscopes and MEMS inertial units. Fusing GNSS positioning information with inertial navigation information achieves high-precision positioning and navigation.

[0009] S3. Navigation in the state of satellite signal disconnection: The system automatically detects the interruption of GNSS signal, activates the inertial navigation dominant mode, enables the hydroacoustic velocimeter and geomagnetic module, and integrates inertial navigation, hydroacoustic velocimetry and geomagnetic navigation information to achieve comprehensive positioning;

[0010] S4. Navigation in satellite signal denial environments: When the system determines that it has entered a satellite signal denial environment, it automatically calls the similar route library and selects the best similar route as a navigation reference to achieve intelligent endurance.

[0011] Preferably, the satellite-inertial combination mode includes two modes: loose coupling and tight coupling, which are adaptively selected according to the navigation accuracy requirement.

[0012] Preferably, the hydroacoustic velocimeter measures the speed of the ship relative to the water body based on the Doppler principle, and converts the relative speed into an absolute speed by estimating the water flow speed.

[0013] Preferably, the geomagnetic module performs auxiliary positioning by measuring the earth's magnetic field information and combining it with a geomagnetic matching algorithm.

[0014] Preferably, the similar route matching algorithm includes: inputting the current status data of the ship, extracting candidate routes, calculating the route similarity, weighted scoring and sorting, selecting the optimal route, and outputting an updated route library.

[0015] Preferably, the route similarity calculation takes into account three factors: spatial distance, heading consistency and speed matching.

[0016] Preferably, the adaptive switching of the navigation mode includes: real-time monitoring of satellite signal quality and navigation system accuracy, automatically switching the navigation mode according to a preset threshold, and when the satellite signal is restored, the system automatically switches back to the GNSS dominant mode.

[0017] Preferably, the dynamic update of the similar route library includes: recording actual navigation track data of the ship, extracting features of the navigation data and storing them in categories, regularly updating the similar route library, and optimizing the route matching algorithm.

[0018] Beneficial effects

[0019] The present invention provides a shipborne intelligent navigation method based on satellite-inertial navigation technology. Compared with existing technologies, it has the following advantages:

[0020] (1) This shipborne intelligent navigation method based on satellite-inertial combination technology can maintain high navigation accuracy and reliability even in an environment where the ship's satellite signal is disconnected or denied through the satellite-inertial combination technology, thereby achieving all-weather, high-reliability navigation. In addition, through the fusion of multi-source navigation information, it can effectively resist the interference faced by a single navigation method and improve the anti-interference capability of the navigation system.

[0021] (2) This shipborne intelligent navigation method based on satellite-inertial combined technology enables the ship's navigation mode to be intelligent without human intervention through automatic switching of navigation modes. Secondly, through dynamic updates of the similar route library, the navigation system can continuously improve the navigation effect and enhance its self-learning ability.

[0022] (3) This shipborne intelligent navigation method based on satellite-inertial combined technology has a wide range of applications and is suitable for various ship types such as civilian ships, military ships, and special ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process of the present invention;

[0024] Figure 2 This is a diagram of the navigation system architecture of the present invention;

[0025] Figure 3 This is a flowchart of the navigation strategy of the present invention;

[0026] Figure 4 This is a flow chart of the similar route matching algorithm of the present invention. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] See also Figure 1-4 The present invention provides a technical solution: a shipborne intelligent navigation method based on satellite-inertial combined technology, which specifically includes the following steps:

[0029] Step 1: System initialization: Start the ship's navigation system, including a high-precision GNSS receiver, fiber optic gyroscope, MEMS inertial unit, hydroacoustic velocimeter, geomagnetic module, and a similar route library;

[0030] High-precision GNSS receiver: uses a multi-frequency receiver and supports RTK technology to achieve centimeter-level positioning accuracy;

[0031] Fiber optic gyroscope: uses fiber optic wrap technology, has high precision and high reliability, and is used to measure the angular velocity of the ship;

[0032] MEMS inertial unit: Using micro-electromechanical system technology, it contains a three-axis accelerometer and a three-axis gyroscope to measure the ship's linear acceleration and angular velocity;

[0033] Hydroacoustic velocimeter: uses the Doppler principle to measure the speed of the ship relative to the water body and provide a three-dimensional velocity vector;

[0034] Geomagnetic module: used to measure the Earth's magnetic field and assist in positioning in combination with geomagnetic matching algorithm;

[0035] Similar route database: stores historical navigation data and typical route patterns, and supports route matching function;

[0036] Main control unit: core processing unit, responsible for navigation information fusion, navigation mode switching and similar route matching;

[0037] Display terminal: displays navigation information and system status.

[0038] System initialization

[0039] a1. System power-on self-test: Check the connection status of each hardware module, check whether the sensor is working properly, and verify the integrity of the similar route library.

[0040] a2. Initial sensor calibration: cold start or hot start the GNSS receiver to obtain the initial position;

[0041] Inertial sensor zero bias calibration and scale factor calibration;

[0042] Hydroacoustic velocimeter sound velocity calibration;

[0043] Geomagnetic module hard and soft magnetic calibration.

[0044] a3. Initial alignment:

[0045] GNSS information and geomagnetic information are used to perform coarse alignment, static alignment and dynamic fine alignment to establish a navigation coordinate system.

[0046] a4. Determination of initial position:

[0047] Receive GNSS signals and determine the initial position. If GNSS signals are unavailable, the initial position is calculated using the last known position and inertial navigation.

[0048] Step 2: Navigation under normal satellite signal conditions:

[0049] Use high-precision GNSS receivers to obtain centimeter-level positioning information;

[0050] Obtain ship attitude information through the fusion of fiber optic gyroscope and MEMS inertial unit;

[0051] Loosely couple or tightly couple GNSS positioning information with inertial navigation information to achieve high-precision positioning and navigation.

[0052] b1. High-precision GNSS positioning:

[0053] Receive GNSS signals, including GPS, BeiDou and GLONASS satellite system signals;

[0054] Apply RTK technology to achieve centimeter-level positioning accuracy;

[0055] Real-time evaluation of GNSS signal quality and accuracy indicators;

[0056] b2. Posture determination:

[0057] The fiber optic gyroscope measures the angular velocity and integrates it to obtain the attitude angle;

[0058] MEMS inertial unit provides auxiliary attitude information;

[0059] Fusion of two inertial sensor data to improve attitude determination accuracy and reliability;

[0060] b3. Satellite-inertial combined navigation:

[0061] Use loosely coupled or tightly coupled methods to fuse GNSS and inertial navigation information;

[0062] Apply the extended Kalman filter algorithm to estimate system state and error;

[0063] Correct inertial navigation system errors in real time to improve navigation accuracy and stability.

[0064] Step 3: Navigation when satellite signal is disconnected:

[0065] The system automatically detects that the GNSS signal is interrupted;

[0066] Activate the inertial navigation dominant mode, with the inertial navigation system as the main focus;

[0067] Enable the hydroacoustic velocimeter to obtain the ship's speed information relative to the water body and correct the accumulated error of inertial navigation;

[0068] Enable the geomagnetic module to obtain geomagnetic field information and use the geomagnetic field matching algorithm for auxiliary positioning;

[0069] Integrate inertial navigation, hydroacoustic velocity measurement and geomagnetic navigation information to achieve comprehensive positioning.

[0070] c1. Disconnection detection and assessment:

[0071] Monitor GNSS signal strength, satellite number and geometric distribution;

[0072] Detecting GNSS positioning accuracy degradation or signal loss;

[0073] Evaluate disconnection time and recovery time;

[0074] c2. Inertial navigation dominant mode activation:

[0075] Automatically switch to inertial navigation dominant mode;

[0076] Calculate the position based on the last valid GNSS information and inertial sensor data;

[0077] c3. Hydroacoustic velocity measurement assistance:

[0078] Activate the hydroacoustic velocimeter to measure the speed of the ship relative to the water;

[0079] Calculate the velocity relative to the Earth, taking into account the effects of water flow;

[0080] Use velocity information to correct the accumulated error of inertial navigation;

[0081] c4. Geomagnetic navigation assistance:

[0082] Collect geomagnetic field information and combine it with geomagnetic field map;

[0083] Apply geomagnetic matching algorithm to assist positioning;

[0084] Enhance magnetic navigation accuracy through magnetic field gradient information;

[0085] c5. Multi-source navigation information fusion:

[0086] Design multi-source information fusion model;

[0087] Fusion of multi-source navigation information based on particle filtering or federated Kalman filtering algorithms; dynamic adjustment of the weights of each navigation method to optimize the fusion results.

[0088] Step 4: Navigation in a satellite signal denial environment:

[0089] The system determines that it has entered a satellite signal denial environment;

[0090] Automatically call the similar route library, match the current navigation environment based on historical data, and select the best similar route as a navigation reference;

[0091] Combining inertial navigation, hydroacoustic speed measurement and geomagnetic navigation information, intelligent endurance is achieved.

[0092] d1. Denial of environmental identification:

[0093] Analyze GNSS signal interruption characteristics;

[0094] Combine environmental information to determine whether to enter a denied environment;

[0095] Assess the scope and duration of the denial environment;

[0096] d2. Calling similar route library:

[0097] Retrieve matching routes from a similar route library based on current position, heading, and historical data;

[0098] Calculate the similarity between the current navigation trajectory and the routes in the library;

[0099] Select the route with the highest similarity as a navigation reference;

[0100] d3. Similar route matching algorithm: Figure 4 As shown, the following steps are included:

[0101] Input the current status data of the ship;

[0102] Extract candidate routes from the route database;

[0103] Calculate route similarity, taking into account spatial distance, heading consistency, and speed matching;

[0104] Perform weighted scoring and sorting;

[0105] Select the best route as a navigation reference;

[0106] Continuously update the route database based on actual navigation conditions;

[0107] d4, Intelligent battery life:

[0108] Generate the optimal navigation path based on similar routes and multi-source navigation information;

[0109] Autonomously adjust the ship's course and speed according to set safety standards;

[0110] Monitor navigation safety in real time to avoid collision and grounding risks.

[0111] Step 5: Adaptive switching of navigation mode:

[0112] Real-time monitoring of satellite signal quality and navigation system accuracy;

[0113] Automatically switch navigation modes based on preset thresholds;

[0114] When the satellite signal is restored, the system automatically switches back to GNSS dominant mode.

[0115] e1. Navigation performance evaluation:

[0116] Establishing multiple navigation performance indicators, including positioning accuracy, reliability, and integrity;

[0117] Calculate the performance indicators of each navigation mode in real time;

[0118] Set the threshold conditions for mode switching;

[0119] e2. Adaptive switching strategy: Figure 3 As shown, different navigation modes are automatically switched according to the satellite signal status:

[0120] When the signal is normal, the GNSS+inertial navigation combination is used;

[0121] When the signal is disconnected, it switches to the inertial + hydroacoustic + geomagnetic combination;

[0122] When entering a denied environment, it uses a similar route library to intelligently continue flight;

[0123] Automatically switch back to GNSS dominant mode when signal is restored;

[0124] e3. Smooth transition mechanism:

[0125] Design smooth transition algorithms between navigation modes;

[0126] Avoid positioning jumps when switching modes;

[0127] Ensure continuity and consistency of navigation information.

[0128] Step 6: Dynamic update of similar route database:

[0129] Record the actual navigation track data of the ship;

[0130] Extract features and classify and store navigation data;

[0131] Regularly update the similar route database and optimize the route matching algorithm.

[0132] f1. Navigation data collection:

[0133] Record the ship's actual navigation track, speed, and heading information;

[0134] Marking special navigation environments and operating modes;

[0135] Preprocess the data to remove outliers;

[0136] f2. Route feature extraction:

[0137] Extract key feature points of the route;

[0138] Calculate the characteristic parameters of the flight segment, such as curvature, steering angle, and speed change; construct the route characteristic vector;

[0139] f3. Route classification and storage:

[0140] Cluster analysis based on route characteristics;

[0141] Tagging management of routes;

[0142] Establish a structured route database;

[0143] f4. Route library optimization and update:

[0144] Regularly evaluate the frequency and accuracy of each route in the route database; merge routes with high similarity, delete outdated and low-quality routes; introduce new high-quality routes to maintain the representativeness and practicality of the database.

Claims

1. A shipborne intelligent navigation method based on satellite-inertial combined technology, characterized by: The specific steps include: S1. System initialization: Start the ship's navigation system, including a high-precision GNSS receiver, fiber optic gyroscope, MEMS inertial unit, hydroacoustic velocimeter, geomagnetic module, and a similar route library; S2. Navigation under normal satellite signal conditions: Use high-precision GNSS receivers to obtain centimeter-level positioning information, and obtain ship attitude information through the fusion of fiber optic gyroscopes and MEMS inertial units. Fusing GNSS positioning information with inertial navigation information achieves high-precision positioning and navigation. S3. Navigation in the state of satellite signal disconnection: The system automatically detects the interruption of GNSS signal, activates the inertial navigation dominant mode, enables the hydroacoustic velocimeter and geomagnetic module, and integrates inertial navigation, hydroacoustic velocimetry and geomagnetic navigation information to achieve comprehensive positioning; S4. Navigation in satellite signal denial environments: When the system determines that it has entered a satellite signal denial environment, it automatically calls the similar route library and selects the best similar route as a navigation reference to achieve intelligent endurance.

2. The shipborne intelligent navigation method based on satellite-inertial combined technology according to claim 1, characterized in that: The satellite-inertial combination mode includes loose coupling and tight coupling, which are adaptively selected according to the navigation accuracy requirements.

3. The shipborne intelligent navigation method based on satellite-inertial combined technology according to claim 1, characterized in that: The hydroacoustic velocimeter measures the speed of a ship relative to the water body based on the Doppler principle and converts the relative speed into an absolute speed by estimating the water flow speed.

4. The shipborne intelligent navigation method based on satellite-inertial combined technology according to claim 1, characterized in that: The geomagnetic module performs auxiliary positioning by measuring the earth's magnetic field information and combining it with a geomagnetic matching algorithm.

5. The shipborne intelligent navigation method based on satellite-inertial combined technology according to claim 1, characterized in that: The similar route matching algorithm includes: inputting the current status data of the ship, extracting candidate routes, calculating the route similarity, weighted scoring and sorting, selecting the optimal route, and outputting an updated route library.

6. The shipborne intelligent navigation method based on satellite-inertial combined technology according to claim 5, characterized in that: The route similarity calculation takes into account three factors: spatial distance, heading consistency and speed matching.

7. The shipborne intelligent navigation method based on satellite-inertial combined technology according to claim 1, characterized in that: The adaptive switching of navigation modes includes: real-time monitoring of satellite signal quality and navigation system accuracy, automatic switching of navigation modes according to preset thresholds, and when the satellite signal is restored, the system automatically switches back to the GNSS dominant mode.

8. The shipborne intelligent navigation method based on satellite-inertial combined technology according to claim 1, characterized in that: The dynamic update of the similar route library includes: recording the actual navigation track data of the ship, extracting features of the navigation data and storing them in categories, regularly updating the similar route library, and optimizing the route matching algorithm.

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