Ship fusion positioning system

Abstract

The invention discloses a ship fusion positioning system. Comprising at least one receiving module configured to receive a GPS signal and a BDS signal; the data processing module is configured to preprocess the GPS signal and the BDS signal and establish a pseudo-range double-difference observation equation to execute double-difference calibration so as to eliminate satellite clock difference and receiver clock difference; the combined positioning module is configured to execute GPS / BDS combined positioning based on the preprocessed data, including performing carrier phase relative positioning by using a pseudo-range positioning result as an initial value, and executing time synchronization calibration and coordinate system calibration; and the transmission module is configured to transmit the positioning data to an upper-layer system through a 5G network and a VHF network in a dual-mode manner, and select a transmission mode according to the network coverage condition and the signal quality. According to the invention, through a combined positioning mode of the GPS and the Beidou (BDS), the acquisition of traditional AIS data information is improved.

Description

Technical Field

[0001] This invention relates to the field of communication, navigation and positioning technology, and more specifically to a ship fusion positioning system. Background Technology

[0002] AIS is a high-level Automatic Identification System for ships, a common intelligent shipborne terminal used in navigation, waterway management, and maritime traffic control. However, traditional AIS uses VHF for data transmission, with an update frequency of once every 2-10 seconds, resulting in low data transmission rate and low accuracy.

[0003] Traditionally, AIS functions such as positioning and ship speed measurement are performed by GPS. However, GPS does not perform ideally in China, especially on inland waterways such as the Yangtze River.

[0004] Therefore, a ship fusion positioning system is provided to improve the acquisition of traditional AIS data information by combining GPS and BeiDou (BDS) positioning methods. Summary of the Invention

[0005] To address the above problems, the present invention provides a ship fusion positioning system.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: Ship integrated positioning system includes: At least one receiving module is configured to receive GPS signals and BDS signals; The data processing module is configured to preprocess the GPS signal and the BDS signal, establish a pseudorange double-difference observation equation and perform double-difference calibration to eliminate satellite clock errors and receiver clock errors; The integrated positioning module is configured to perform GPS / BDS integrated positioning based on preprocessed data, including using pseudorange positioning results as initial values ​​for carrier phase relative positioning, and performing time synchronization calibration and coordinate system calibration to obtain positioning data; The transmission module is configured to transmit the positioning data to the upper-layer system in dual mode via 5G and VHF networks, and select the transmission mode according to the network coverage and signal quality. When the 5G network signal strength is higher than a preset threshold, the 5G network is used to achieve high-bandwidth real-time transmission, and when the 5G network signal strength is lower than the preset threshold, the transmission is switched to VHF network, or dual-network transmission is enabled at the same time to enhance data reliability.

[0007] As a preferred embodiment, the data processing module is further configured to filter the GPS signal and BDS signal to reduce multipath effects and noise interference, and to perform observation redundancy verification based on the number of visible satellites. When the total number of visible satellites exceeds a preset threshold, a combined positioning redundancy mode is enabled to improve positioning stability.

[0008] As a preferred embodiment, the combined positioning module is configured to increase the weight of BDS satellite data in the Yangtze River bend area and increase the weight of GPS satellite data in the coastal area to compensate for the impact of the regional environment on positioning accuracy.

[0009] Compared with the prior art, the present invention has the following advantages: Within satellite navigation systems, precise positioning results can be achieved through the observation redundancy provided by a large number of visible satellites. However, by employing methods such as the BeiDou-GPS dual-constellation combination, the number of visible satellites increases, thereby ensuring the reliability and stability of practical applications. Furthermore, with the ever-expanding application scope of the BeiDou satellite navigation system, its technical specifications, both domestically and in the Asia-Pacific region, can meet the actual needs of users. Considering the clarity of its rules, standards, and data encoding methods, this system is similar to the GPS system, but in terms of constellation composition, it can effectively expand and integrate with the GPS system. Based on the differences in characteristics between GPS and BeiDou satellite navigation systems, these two systems can be integrated to achieve functional complementarity, thereby increasing the observation redundancy during navigation. This not only ensures accuracy but also provides crucial guarantees for positioning stability, enabling its development in more in-depth and extensive directions.

[0010] By leveraging these complementary strengths, combining BeiDou and GPS for positioning will be an inevitable trend in future maritime applications. GPS is a globally accepted maritime standard and has been indispensable in long-term maritime use. BeiDou, on the other hand, has significant advantages in my country's development. Therefore, combining the strengths of both satellite positioning systems and leveraging their respective advantages to achieve integrated positioning can bring substantial improvements to the Yangtze River Inland Waterway VTS system. Attached Figure Description

[0011] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0012] Figure 1 A structural block diagram of the system provided in the embodiments of this disclosure.

[0013] Figure 2 This is a schematic diagram of the combined positioning module provided in this embodiment.

[0014] Figure 3 This is a schematic diagram of the shipborne data center provided in this embodiment.

[0015] Figure 4 This is a schematic diagram of the ship navigation system provided in this embodiment. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] This disclosure provides a ship fusion positioning system, such as Figure 1 As shown, it includes: at least one receiving module configured to receive GPS signals and BDS signals; The data processing module is configured to preprocess the GPS signal and the BDS signal, establish a pseudorange double-difference observation equation and perform double-difference calibration to eliminate satellite clock errors and receiver clock errors; The integrated positioning module is configured to perform GPS / BDS integrated positioning based on preprocessed data, including using pseudorange positioning results as initial values ​​for carrier phase relative positioning, and performing time synchronization calibration and coordinate system calibration to obtain positioning data; The transmission module is configured to transmit the positioning data to the upper-layer system in dual mode via 5G and VHF networks, and select the transmission mode according to the network coverage and signal quality. When the 5G network signal strength is higher than a preset threshold, the 5G network is used to achieve high-bandwidth real-time transmission, and when the 5G network signal strength is lower than the preset threshold, the transmission is switched to VHF network, or dual-network transmission is enabled at the same time to enhance data reliability.

[0018] As a preferred embodiment, the data processing module is further configured to filter the GPS signal and BDS signal to reduce multipath effects and noise interference, and to perform observation redundancy verification based on the number of visible satellites. When the total number of visible satellites exceeds a preset threshold, a combined positioning redundancy mode is enabled to improve positioning stability.

[0019] As a preferred embodiment, the combined positioning module is configured to increase the weight of BDS satellite data in the Yangtze River bend area and increase the weight of GPS satellite data in the coastal area to compensate for the impact of the regional environment on positioning accuracy.

[0020] Specifically, in this embodiment, to improve accuracy, the double difference between the two satellites and the receiver is often calculated. This calculation can eliminate satellite clock bias and receiver clock bias. Therefore, a double-difference model for combined positioning is established. Pseudorange positioning has advantages in positioning because it does not require analysis of integer ambiguity or analysis of frequency differences between the two systems, and it can provide initial values ​​for carrier phase positioning. In GNSS positioning, carrier phase relative positioning is a high-precision positioning method, and carrier phase double difference can achieve millimeter-level positioning, which has wide applications in land surveying, precision surveying, and navigation.

[0021] First, establish the pseudorange double-difference observation equations for GPS and BDS systems:

[0022]

[0023] In the formula, the superscripts G and B represent GPS and BDS, respectively. This represents the distance between the station and the satellite, where (X, Y, Z) represent the coordinates of the station. These are satellite coordinates. pseudorange observations; Each represents ionospheric correction and tropospheric correction; e represents multipath and observation noise; That is, the double difference factor; Assuming epoch pairs GPS satellites For a BDS satellite, since there is no pseudorange measurement for the ambiguity unknowns, after double difference, only the three major three-dimensional coordinate increments correspond to the unknown parameters. After linearization, the error equation is obtained:

[0024] in:

[0025] The unknown parameter matrix X has a size of 3×1; the coefficient matrix A has a size of [( -1)+( -1)]×3; the size of the constant matrix L is; [( -1)+( -1)]×1. The least squares method can be used here to solve the above equation. Subsequently, based on the GPS / BDS system, the corresponding carrier phase double-difference observation equation is detailed below:

[0026]

[0027] in, Carrier phase observations N: Integer ambiguity Assuming the epoch has been observed GPS satellites For a given BDS satellite, integer ambiguity cannot be eliminated through double-difference calculation. Assume the total number of GPS double-difference ambiguities is [number missing]. The total number of BDS double-difference ambiguities is Only three three-dimensional coordinate increments correspond to the unknown parameters, and the GPS and BDS double-difference ambiguities are respectively... , One. By combining the above formulas and linearizing them, the error equation is obtained:

[0028] in,

[0029]

[0030] Combined positioning modules, such as Figure 2 As shown, it includes the BeiDou satellite positioning system, the GPS satellite positioning system, and an onboard data processing center. The onboard data center first receives positioning information from both satellites, processes it, and then transmits it to the VTS data center via 5G / VHF for further data processing.

[0031] Shipborne data centers, such as Figure 3 As shown, it mainly consists of a satellite antenna, a data preprocessing center, and a data center. The improved combined satellite positioning shipborne equipment needs to integrate the core module of the ship navigation system, the audio subsystem, the VHF / 5G transmission module, the power supply module, and the operating handle. Its structural diagram is shown below. Figure 4 As shown.

[0032] The main processor controls the display controller CPU and packages various data for processing. It performs dual-difference calibration on data from both BeiDou and GPS positioning. The device also has reserved data interfaces for easy expansion with multiple data ports. The display controller displays combined positioning information such as vessel navigation information, electronic charts, surrounding vessels, position coordinates, and other management information. It can also perform track planning and emergency alarms. The display controller's peripherals include SD card, LCD screen, FLASH, DDR, and USB interfaces, enabling storage expansion and connection to external computers for data export and software upgrades. The data processor preprocesses BeiDou and GPS positioning data, primarily performing satellite positioning time calibration, providing the foundation for the main processor's data processing and performing simple time calibration functions.

[0033] The audio processing unit extracts audio data and information from the main processor, converts the digital audio information directly into analog signals, and then transmits them to the microphone and headphones.

[0034] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, function, and operation of possible implementations of apparatus, methods, and computer program products according to embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than those disclosed in the description; sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based device that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A ship integrated positioning system, characterized in that, include: At least one receiving module is configured to receive GPS signals and BDS signals; The data processing module is configured to preprocess the GPS signal and the BDS signal, establish a pseudorange double-difference observation equation and perform double-difference calibration to eliminate satellite clock errors and receiver clock errors; The integrated positioning module is configured to perform GPS / BDS integrated positioning based on preprocessed data, including using pseudorange positioning results as initial values ​​for carrier phase relative positioning, and performing time synchronization calibration and coordinate system calibration to obtain positioning data; The transmission module is configured to transmit the positioning data to the upper-layer system in dual mode via 5G and VHF networks, and select the transmission mode according to the network coverage and signal quality. When the 5G network signal strength is higher than a preset threshold, the 5G network is used to achieve high-bandwidth real-time transmission, and when the 5G network signal strength is lower than the preset threshold, the transmission is switched to VHF network, or dual-network transmission is enabled at the same time to enhance data reliability.

2. The ship fusion positioning system according to claim 1, characterized in that, The data processing module is further configured to filter the GPS signal and BDS signal to reduce multipath effects and noise interference, and to perform observation redundancy verification based on the number of visible satellites. When the total number of visible satellites is greater than a preset threshold, a combined positioning redundancy mode is enabled to improve positioning stability.

3. The ship fusion positioning system according to claim 1, characterized in that, The combined positioning module is configured to increase the weight of BDS satellite data in the Yangtze River bend area and increase the weight of GPS satellite data in the coastal area to compensate for the impact of the regional environment on positioning accuracy.

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