Railway signal intensifier ad hoc network management method and system based on Beidou fusion positioning

Abstract

The invention relates to the technical field of railway signal enhancement, and discloses a railway signal enhancer ad-hoc network management method and system based on Beidou fusion positioning, and the method comprises the steps: a signal enhancer receives a Beidou satellite signal, calculates the initial coordinate of the signal enhancer, monitors a communication signal from a ground control base station, and transmits the communication signal to the ground control base station; when the communication signal level is lower than a first preset threshold value or the data packet loss rate is higher than a second preset threshold value, a differential relay mode is triggered, one signal enhancer is selected from a plurality of signal enhancers to serve as a temporary main reference, and the differential quality factor of each device serves as an input weight through a weighted least square algorithm; and the signal intensifier which is not elected as the temporary main reference receives the differential correction data sent by the temporary main reference and corrects the initial coordinate of the signal intensifier by using the data, so that the intelligence, the reliability and the stability of system operation and maintenance in a complex railway environment are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of railway signal enhancement, and discloses a railway signal enhancer ad hoc network management method and system based on Beidou integrated positioning. BACKGROUND

[0002] The railway signal enhancer is a key device for ensuring the coverage of railway communication signals. The traditional device has many shortcomings, for example: the device lacks self-positioning and reporting capabilities, and after a fault occurs, the maintenance personnel needs to check along the railway line point by point, which is low in efficiency and high in cost; in mountainous areas, tunnel areas and other mobile public network missing areas, the communication link between the device and the remote operation and maintenance platform is interrupted, and state monitoring cannot be realized; the construction cost of the traditional GNSS reference station is high, and it cannot be deployed mobile, resulting in a lack of effective differential positioning coverage in long and large railway sections, and the positioning accuracy of the device is limited. SUMMARY

[0003] To solve the above technical problems, the main purpose of the present application is to provide a railway signal enhancer ad hoc network management method and system based on Beidou integrated positioning, wherein the railway signal enhancer ad hoc network management method based on Beidou integrated positioning comprises: The signal enhancer receives the Beidou satellite signal and solves the initial coordinates of itself; The signal enhancer monitors the communication signal from the ground control base station, and triggers the differential relay mode when the communication signal level is lower than the first preset threshold or the data packet loss rate is higher than the second preset threshold; In the differential relay mode, a plurality of signal enhancers interact with each other through the ad hoc network link to obtain the differential quality factor of each device; Based on the differential quality factor, one of the plurality of signal enhancers is elected as a temporary master reference, and the election is performed by using the weighted least squares algorithm with the differential quality factor of each device as the input weight; The signal enhancer that is not elected as the temporary master reference receives the differential correction data sent by the temporary master reference, and modifies the initial coordinates of itself by using the data; Each signal enhancer sends the modified coordinates and the device running state data to the remote operation and maintenance platform through the Beidou short message function.

[0004] As a preferred scheme of the railway signal enhancer ad hoc network management method based on Beidou integrated positioning, wherein: The method for the signal enhancer to receive the Beidou satellite signal and solve the initial coordinates of itself comprises: The signal enhancer receives the satellite signal from the Beidou navigation satellite system through the Beidou positioning module; The satellite signal is solved in real time by using the single point positioning mode, and the initial coordinates of the signal enhancer containing the longitude, latitude and elevation are output.

[0005] As a preferred scheme of the application, the method comprises the following steps: The signal enhancer acquires the radio frequency signal level and the data packet transmission packet loss rate of the communication link between the signal enhancer and the ground control base station in real time through a preset signal detection module; the condition for triggering the differential relay mode is that the radio frequency signal level is lower than the first preset threshold, indicating that the wireless channel quality is deteriorated; and the data packet loss rate is higher than the second preset threshold, indicating that the network connectivity is decreased.

[0006] As a preferred scheme of the application, the method comprises the following steps: When the direct communication link quality between the signal enhancer and the ground control base station is deteriorated, a cooperative working mode is triggered by a single signal enhancer and constructed between multiple adjacent signal enhancers through the ad hoc network link; In the differential relay mode, each signal enhancer interacts with the differential positioning data through the ad hoc network link, and a temporary master reference is generated through dynamic election, and the differential correction data is provided to other slave devices in the network through the temporary master reference.

[0007] As a preferred scheme of the application, the method comprises the following steps: The signal enhancer periodically exchanges data packets in the ad hoc network link in a multi-hop broadcast manner through the ad hoc network communication module, and the data packets at least contain the original pseudo-range observation value, the carrier phase observation value and the differential quality factor of the signal enhancer itself; In the dynamic election process, each signal enhancer collects the differential quality factors of all neighbor devices through the ad hoc network link; Each signal enhancer independently runs a weighted least squares algorithm, taking the differential quality factor as an input weight, to evaluate the fitness of each device as a potential reference; The algorithm takes the maximization of the overall cooperative positioning accuracy of the network after differential correction as the objective function, and iteratively solves through a distributed consensus mechanism, and finally elects a unique temporary master reference.

[0008] As a preferred scheme of the application, the method comprises the following steps: The differential quality factor is a comprehensive evaluation value, which is acquired by the master control unit of the signal enhancer according to the real-time output of the Beidou positioning module, and the calculation parameters include the weighted mean of the signal-to-noise ratio of the satellite signal, the phase noise variance of the carrier phase lock loop and the geometric distribution accuracy factor of the current visible satellite; The interaction differential quality factor is encapsulated and broadcast as a necessary field of the data packet in the ad hoc network link, and a digital signature is attached.

[0009] As a preferred scheme of the ad hoc network management method of the railway signal booster based on the Beidou integrated positioning, wherein: The process of screening the signal boosters not elected as the temporary master reference is dynamic and distributed: After the completion of the weighted least square algorithm election, the temporary master reference broadcasts a data packet including a reference announcement message of a unique device identification through the ad hoc network link; The signal booster receiving the reference announcement message and identifying itself as not matching the announcement identification configures its own role as a slave device and starts a listening session for receiving differential correction data; If any signal booster does not receive the reference announcement message within a preset time, it is determined that the current network is partitioned, and the election process of the temporary master reference is retriggered in the network partition in which it is located.

[0010] As a preferred scheme of the ad hoc network management method of the railway signal booster based on the Beidou integrated positioning, wherein: The method for correcting the initial coordinates of the signal booster itself by using the differential correction data includes: The slave device receives the differential correction data issued by the temporary master reference; The master control unit of the slave device performs carrier phase real-time dynamic differential positioning calculation on the original pseudo-range observation value and carrier phase observation value of itself and the received differential correction data.

[0011] As a preferred scheme of the ad hoc network management method of the railway signal booster based on the Beidou integrated positioning, wherein: The method for sending the corrected coordinates and device operation state data through the Beidou short message function includes: The master control unit of the signal booster encapsulates and prioritizes the data to be sent; Device fault alarm information and coordinate abnormal data are marked as high priority, and regular state monitoring data are marked as low priority; The Beidou short message module dynamically allocates communication resources according to the priority of the data and preferentially sends high-priority data; After receiving the data, the remote operation and maintenance platform parses the corrected coordinates and device operation state data according to the embedded protocol.

[0012] As a preferred scheme of the ad hoc network management method of the railway signal booster based on the Beidou integrated positioning, wherein: The positioning module comprises a signal receiving unit and a coordinate solving unit; The signal detection module comprises a level collecting unit and a packet loss rate statistical unit; The mode control module comprises a threshold comparison unit and a mode triggering unit, wherein the threshold comparison unit compares the collected signal level with a first preset threshold and the packet loss rate with a second preset threshold, and the mode triggering unit triggers the differential relay mode when any condition is met; The ad hoc network communication module comprises a data packaging unit and a multi-hop transmission unit, wherein the data packaging unit packages the original observation value and the differential quality factor into a data packet, and the multi-hop transmission unit transmits the data in the ad hoc network link in a multi-hop broadcast manner through a protocol; The reference election module comprises a factor aggregation unit and an algorithm solving unit, wherein the factor aggregation unit collects the differential quality factors of neighboring devices, and the algorithm solving unit elects a temporary master reference by using a weighted least squares algorithm with the differential quality factors as input weights; The differential correction module comprises a data receiving unit and an RTK solving unit; the data back transmission module comprises a priority scheduling unit and a short message communication unit; and the master control module comprises a flow control unit and a cooperative management unit.

[0013] The application has the following beneficial effects: The application realizes autonomous positioning through the Beidou module, directly returns the device position and state to the operation and maintenance platform in a public network-free environment in combination with the Beidou short message function, solves the problem that fault positioning depends on manual troubleshooting, and greatly improves the operation and maintenance efficiency.

[0014] The application automatically triggers the differential relay mode by monitoring the communication quality with the ground base station, dynamically elects a temporary master reference based on the differential quality factor, and distributes differential correction data by using the ad hoc network link, so that a dynamic differential network with centimeter-level precision can be formed in the area along the railway without coverage of traditional reference stations, and the problem of insufficient differential coverage is solved.

[0015] The system formed by the application does not depend on fixed central nodes, when local devices fail or the network topology changes, the system can automatically reorganize and re-elect the reference through the ad hoc network link, continuously provide positioning enhancement and state back transmission services, and ensure the intelligence, reliability and stability of system operation and maintenance in complex railway environments. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without paying creative labor. Among them: Figure 1 The flow chart of the railway signal enhancer ad hoc network management method based on Beidou fusion positioning of the present application; Figure 2 The composition diagram of the railway signal enhancer ad hoc network management system based on Beidou fusion positioning of the present application; Figure 3 The main station plays the main reference in the railway signal enhancer ad hoc network management method based on Beidou fusion positioning of the present application. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings of the specification.

[0018] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented by other ways different from those described herein, and those skilled in the art can make similar generalization without departing from the connotation of the present application, therefore the present application is not limited by the specific embodiments disclosed below.

[0019] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an independent or alternative embodiment.

[0020] Embodiment 1 As Figure 1 The railway signal enhancer ad hoc network management method based on Beidou fusion positioning, comprising: The signal enhancer receives the Beidou satellite signal and solves the initial coordinates of itself; The method for the signal enhancer to receive the Beidou satellite signal and solve the initial coordinates of itself comprises: The signal enhancer receives satellite signals from the Beidou-3 satellite navigation system through the Beidou positioning module; The satellite signals are solved in real time by single point positioning mode, and the initial coordinates of itself containing longitude, latitude and elevation are output.

[0021] In the present application, a preferred method for real-time solving by single point positioning mode includes: The signal booster receives the downlink navigation signals from the Beidou satellite navigation system through its built-in Beidou positioning module, first down-converts and demodulates the received radio frequency signals, and parses the navigation message from the signal structure. The navigation message contains key parameters for positioning solution, including the precise orbit parameters of the satellite and system time information.

[0022] The Beidou positioning module measures the transmission time delay of the signal by comparing the pseudo-random code generated internally by the receiver with the received satellite pseudo-random code, and multiplies the time delay by the speed of light to calculate the pseudo-range observation value between the satellite and the signal booster. In a preferred example, the pseudo-range observation value can be a comprehensive distance observation value that includes receiver clock error, satellite clock error, ionospheric delay, tropospheric delay, and other error sources.

[0023] The Beidou positioning module uses the obtained orbit parameters of multiple satellites and the obtained corresponding pseudo-range observation values to construct a positioning solution equation set. The positioning module includes a position solution engine to solve the positioning solution equation set.

[0024] In this application, a preferred implementation method of the positioning solution equation includes: The Beidou-based integrated positioning railway signal booster autonomously calculates the spatial position by receiving signals from the Beidou satellite navigation system.

[0025] The positioning solution process is based on the space intersection of trilateration. The signal booster calculates the pseudo-range observation value containing various error sources by measuring the radio signal propagation time delay between multiple on-orbit Beidou satellites. Each satellite provides a pseudo-range observation equation. By solving multiple equations simultaneously, the spatial coordinates of the receiver in a specific coordinate system and the receiver clock error are calculated.

[0026] Further, the observation equation is established. For the i-th visible Beidou satellite, the pseudo-range observation equation is expressed as follows: Pseudo-range observation value = geometric distance between satellite and receiver + distance deviation caused by receiver clock error + propagation path error + observation noise Where: the geometric distance between the satellite and the receiver is determined by the instantaneous spatial coordinates of the satellite and the to-be-solved spatial coordinates of the receiver.

[0027] The instantaneous spatial coordinates are obtained by decoding the ephemeris parameters in the navigation message; Distance deviation caused by receiver clock error: there is a deviation between the local clock of the receiver and the Beidou system time, and the product of the deviation and the speed of light constitutes a common distance error term.

[0028] The propagation path error includes ionospheric delay, tropospheric delay, and other errors caused by the influence of the medium on the signal during propagation.

[0029] The observation noise includes random errors such as multipath effects and internal thermal noise of the receiver.

[0030] Further, four or more Beidou satellites are observed to solve four unknown parameters, i.e., three-dimensional spatial coordinates (X, Y, Z) of the receiver and receiver clock error, and a super-equation set composed of four or more pseudo-range observation equations is constructed.

[0031] Specifically, the super-equation set is a nonlinear equation. In a specific implementation, the built-in position solving method of the signal booster includes: By using the Taylor formula, the nonlinear observation equation is expanded at the approximate point, the first-order term is retained, and the nonlinear problem is converted into a linear problem.

[0032] Further, the difference between the pseudo-range observation value and the calculated value based on the approximate coordinates is taken as an observation residual, and a linearized error equation set is constructed.

[0033] Further, the linear equation set is solved by a least square estimation algorithm to obtain optimal estimates of the receiver coordinate correction and clock error correction.

[0034] The approximate coordinates are updated by the new coordinates obtained by solving, and the linearization and solving process is repeated for iterative calculation until the coordinate correction is less than a preset convergence threshold, and finally the high-precision initial coordinates of the receiver, including longitude, latitude, and elevation, are output.

[0035] Specifically, the solving process is performed by iterative calculation to find the optimal three-dimensional spatial coordinate point and receiver clock error, so that the difference between the calculated distance from the point to all observed satellites and the measured pseudo-range is minimized, and the initial coordinates of the signal booster are output. The coordinates are expressed in the form of the geodetic coordinate system and include longitude, latitude, and elevation.

[0036] The signal booster monitors the communication signals from the ground control base station, and triggers the differential relay mode when the communication signal level is lower than a first preset threshold or the data packet loss rate is higher than a second preset threshold. The signal booster acquires the radio frequency signal level of the communication link between the signal booster and the ground control base station and the transmission packet loss rate of the data packet by a preset signal detection module. The condition for triggering the differential relay mode is that the radio frequency signal level is lower than the first preset threshold, indicating that the wireless channel quality is deteriorated, and the data packet loss rate is higher than the second preset threshold, indicating that the network connectivity is decreased.

[0037] Specifically, the signal booster monitors the communication signals from the ground control base station, and triggers the specific implementation method of differential relay mode when the signal level or packet loss rate does not meet the conditions, which includes: The signal booster monitors the quality of the communication link with the ground control base station through the built-in signal detection module.

[0038] The module obtains the strength of the downlink radio frequency signal from the ground control base station in real time by measuring the power of the receiving channel, and the strength value is the communication signal level.

[0039] The module counts the specific protocol data packets sent to or received from the ground control base station at the application layer, and calculates the proportion of data packets that do not receive effective responses within a pre-set time window to obtain the transmission packet loss rate of the data packets in real time.

[0040] The signal detection module compares the real-time collected radio frequency signal level with the first preset threshold preset in the device, and at the same time, compares the real-time statistical data packet loss rate with the second preset threshold preset in the device. The two thresholds are pre-set based on the minimum link quality required to maintain stable communication with the ground control base station.

[0041] Further, a preferred trigger is an automatic logic decision process based on the comparison results: When the real-time collected radio frequency signal level is lower than the first preset threshold, it is determined that the wireless channel quality is deteriorated and the physical layer connection is unreliable.

[0042] When the real-time statistical data packet loss rate is higher than the second preset threshold, it is determined that the network connectivity is decreased and the data transmission link is unreliable.

[0043] As long as any of the above conditions is met, the main control unit of the signal booster automatically triggers the differential relay mode.

[0044] When the direct communication link quality between the signal booster and the ground control base station deteriorates, a cooperative mode is triggered by a single signal booster and constructed among multiple adjacent signal boosters through the ad hoc network link; In the differential relay mode, each signal booster interacts with the differential data through the ad hoc network link, and generates a temporary master reference through dynamic election, and provides differential correction data to other slave devices in the network through the temporary master reference.

[0045] When any signal booster first triggers the mode due to the quality deterioration of the direct communication link with the ground control base station, the device acts as the initiating node, periodically broadcasts the mode initiation signaling containing specific identification through its built-in ad hoc network communication module on the pre-configured communication frequency band. The adjacent signal booster receiving the signaling identifies the need to enter the cooperative working state by analyzing the signaling content, and then activates its ad hoc network communication module and establishes a point-to-point communication link with the initiating node and each other. Through the diffusion of this adjacency relationship, a distributed ad hoc network link is finally autonomously constructed among multiple adjacent signal boosters, forming a temporary device cooperation network.

[0046] After the ad hoc network link is successfully constructed, it enters the stable running phase, and each signal booster in the network periodically broadcasts or exchanges its own positioning differential data through the ad hoc network link. A preferred positioning differential data at least includes its original observation data obtained through the Beidou positioning module, such as pseudo-range, carrier phase and differential quality factor for evaluating the quality of its data.

[0047] In a preferred embodiment, the differential quality factor Q is calculated by the following expression: ; Wherein, SNR represents the weighted average value of the signal-to-noise ratio of all currently visible Beidou satellite signals; represents the phase noise variance of the carrier phase phase-locked loop, reflecting the stability of the carrier phase observation value; DOP represents the geometric distribution precision factor of the currently visible satellites, such as geometric precision factor or position precision factor; 、 and are preset normalized weighting coefficients for balancing the influence of parameters with different dimensions and orders of magnitude on the comprehensive evaluation value.

[0048] The higher the value of the differential quality factor Q, the better the quality of the positioning observation data of the device, and the more suitable it is to be elected as the temporary master reference.

[0049] Specifically, each device collects the differential quality factors of itself and all its neighbor devices, and then normalizes the differential quality factor of each candidate device as its input weight.

[0050] In the differential relay mode, the differential quality factor elects one from multiple signal boosters as a temporary master reference, and the election uses the differential quality factor of each device as the input weight through the weighted least squares algorithm, specifically: Each signal booster collects the differential quality factors broadcasted by all neighboring devices through the ad hoc network link, normalizes the differential quality factors, and converts them into election weights representing the data reliability of each device. Specifically, the higher the differential quality factor of a device, the greater the election weight assigned to the device, and the stronger the influence of the device in the election process.

[0051] Each signal booster independently evaluates the suitability of each candidate device in the network as a potential temporary master reference.

[0052] The evaluation is performed by a preset objective function that simulates the estimated level of overall cooperative positioning accuracy that the entire ad hoc network can achieve after applying the differential correction data of a candidate device serving as a temporary master reference.

[0053] During the evaluation process, the objective function not only considers the differential quality of the candidate device itself but also evaluates the positioning accuracy improvement that the candidate device can bring to other high-weight devices in the network.

[0054] A candidate device with the highest objective function evaluation value is elected as the only temporary master reference.

[0055] Each signal booster independently calculates the objective function evaluation values of all candidate devices and selects the candidate device with the highest evaluation value as the only temporary master reference through comparison.

[0056] Through the weighted least squares algorithm election mechanism, the device that maximizes the cooperative positioning performance of the entire network is intelligently selected as the temporary master reference, ensuring that the elected leader node can most effectively serve the entire network and achieving the intelligence, reliability, and stability of system operation in complex railway environments.

[0057] It should be noted that in the present application, a preferred election algorithm is run by all devices based on the received neighboring device data, and the election algorithm takes the differential quality factors reported by each device as the core input parameter. Through comparison and calculation, for example, the device with the optimal differential quality factor is identified and unanimously agreed to be dynamically elected as a temporary master reference device. This process is distributed and does not rely on any external control node.

[0058] Further, after being elected, the temporary master reference device assumes the function of a reference station, calculates the differential correction amount suitable for the local network environment through its high-quality positioning data, and continuously or periodically broadcasts these differential correction data to other devices in the network through the ad hoc network link.

[0059] In the differential relay mode, multiple signal boosters exchange their respective differential quality factors through ad-hoc network links; Based on the differential quality factors, a temporary master reference is elected from the multiple signal boosters, the election is performed by a weighted least square algorithm with the differential quality factors of each device as input weights; When the direct communication link quality between a signal booster and a ground control base station deteriorates, a cooperative mode is triggered by a single signal booster and constructed among multiple neighboring signal boosters through ad-hoc network links; The election of the temporary master reference based on the weighted least square algorithm is a distributed, algorithm consensus-based process: Each signal booster continuously monitors the ad-hoc network link and collects broadcast data packets from all communicable neighboring devices. From these, the differential quality factor of each neighboring device is parsed.

[0060] As Figure 3 shown, each device independently runs the weighted least square algorithm to complete the election, in the model of the least square algorithm, all neighboring devices in the network are considered as potential reference station candidates.

[0061] A preferred least square algorithm implementation method includes directly using the differential quality factor of each candidate device as the input weight of the candidate device in the algorithm. This means that the higher the differential quality factor of a device, the greater its weight in the election algorithm, reflecting that its data is more reliable.

[0062] Further, the objective function of the weighted least square algorithm is set to maximize the overall network's estimated positioning accuracy factor after differential correction, which is an index that can predict the positioning solution accuracy based on satellite geometry distribution and observation quality calculation.

[0063] The algorithm finds a candidate device that maximizes the value of the above objective function through iterative calculation. Since all devices use the same algorithm and input data for calculation in the same network, the same device is iteratively solved and consistently elected as the only temporary master reference.

[0064] In the differential relay mode, each signal booster exchanges positioning differential data through the ad-hoc network link and generates a temporary master reference through dynamic election, which provides differential correction data to other slave devices in the network through the temporary master reference.

[0065] The signal booster periodically exchanges data packets through its ad-hoc network communication module in the ad-hoc network link in a multi-hop broadcast manner, the data packets at least contain its own original pseudorange observation value, carrier phase observation value, and differential quality factor; The dynamic election is based on the received adjacent device data packet: each signal enhancer takes the differential quality factor of all communicable adjacent devices in the network as the input weight of the weighted least squares algorithm, and calculates the weight value of each device as a potential reference; The algorithm takes the estimated accuracy factor of the overall differential corrected position of the network as the objective function, iteratively solves and elects a unique temporary master reference.

[0066] A preferred, each signal enhancer in the self-organizing network data interaction mechanism network transmits data packets in the self-organizing network link in a multi-hop broadcast manner according to a preset communication period through its built-in self-organizing network communication module. The data packet is encapsulated by a specific network protocol frame format, and its payload data at least includes: The original pseudo-range observation value and carrier phase observation value of the device itself, which are the original observation data necessary for high-precision differential positioning solution.

[0067] The differential quality factor of the device, which is a comprehensive evaluation value for quantifying the reliability and accuracy of its current positioning data.

[0068] Through this periodic, multi-hop forwarding data packet exchange, each device in the network can obtain the above key data of all adjacent devices within its communication range, laying the information foundation for subsequent collaborative calculation.

[0069] The differential quality factor is a comprehensive evaluation value, which is obtained by the master control unit of the signal enhancer according to the real-time output of its Beidou positioning module. The calculation parameters include the weighted mean of the signal-to-noise ratio of the satellite signal, the phase noise variance of the carrier phase lock loop, and the geometric distribution accuracy factor of the current visible satellite; The interactive differential quality factor is encapsulated and broadcast as a necessary field of the data packet in the self-organizing network link, with a digital signature attached.

[0070] The signal enhancer that is not elected as the temporary master reference receives the differential correction data sent by the temporary master reference, and uses the data to correct its initial coordinates; Each signal enhancer sends the corrected coordinates and device running state data to the remote operation and maintenance platform through the Beidou short message function.

[0071] Specifically, the method for correcting the initial coordinates of the device using the differential correction data includes: The slave device receives the differential correction data sent by the temporary master reference, which includes the coordinate observation value correction amount and its covariance matrix of the temporary master reference, etc. A preferred example of the coordinate observation correction quantity is the systematic error correction value calculated by comparing the high-precision Beidou positioning observation data of the temporary master reference device with the accurate coordinates calculated by long-time observation.

[0072] The error correction value is used to represent the specific numerical embodiment of the common error or quasi-common error existing in satellite navigation observation at the temporary master reference device, including a three-dimensional coordinate correction vector and a clock correction quantity.

[0073] Specifically, the three-dimensional coordinate correction vector includes a vector of correction components in the north, east, and height directions. The vector is directly used to compensate for the observation errors of the subordinate device in the corresponding directions.

[0074] The north, east, and height directions can also be represented as X, Y, and Z in the Earth-Centered Earth-Fixed coordinate system.

[0075] The clock correction quantity is the deviation correction value of the clock error of the temporary master reference receiver relative to the Beidou system time, which is used to correct the local clock error of the subordinate device, which affects the pseudorange observation of all satellites.

[0076] The coordinate observation correction quantity is used to transfer the common domain error accurately measured at the temporary master reference device, such as satellite ephemeris error, satellite clock error, and most of the ionospheric and tropospheric delay error, to the subordinate devices within the network.

[0077] The subordinate device effectively eliminates the influence of spatial correlation errors in its local calculation by applying the correction quantity.

[0078] Further, the covariance matrix associated with the coordinate observation correction quantity is a mathematical matrix used to quantify the uncertainty of the correction quantity and the error correlation between components.

[0079] The covariance matrix is a symmetric matrix with dimensions corresponding to the dimensions of the coordinate correction quantity. For example, for three-dimensional coordinates and clock, it is a 4x4 matrix.

[0080] The diagonal elements of the covariance matrix are used to represent the variance of the coordinate observation correction quantity in each component, such as north, east, height, and clock. The smaller the variance of the covariance matrix, the more reliable the correction quantity in that direction.

[0081] The non-diagonal elements of the covariance matrix are used to represent the covariance between different correction components, reflecting the degree of correlation between component errors. For example, the correction error in the height direction may have a certain correlation with the clock correction error.

[0082] When the subordinate device performs data fusion algorithms such as weighted least squares or Kalman filtering, the inverse matrix of the covariance matrix is used as the weight matrix of the correction quantity.

[0083] Further, the correction amount component with small variance is given a higher weight in the calculation.

[0084] Through the non-diagonal elements, the calculation model more accurately describes the error propagation characteristics, avoids the decline in calculation accuracy or even divergence caused by ignoring error correlation, and improves the success rate of integer ambiguity fixing and the reliability of the final positioning result of carrier phase real-time kinematic positioning calculation.

[0085] In specific implementation, the coordinate observation value correction amount and its covariance matrix are calculated and packaged by the master unit of the temporary master reference, and broadcast to the slave devices in the network in a preset period or event triggered manner through the ad hoc network communication module.

[0086] By explicitly limiting the differential correction data to at least include the coordinate observation value correction amount and its covariance matrix, the technical solution ensures that the slave device can obtain an error correction reference when receiving and utilizing the data for local coordinate correction, and can also evaluate the reliability of the reference and perform optimal fusion. The accuracy of cooperative positioning of all signal enhancers in the ad hoc network under complex railway environment is improved.

[0087] The master unit of the slave device performs carrier phase real-time kinematic positioning calculation on the original pseudo-range observation value and carrier phase observation value of itself and the received differential correction data.

[0088] The signal enhancer not elected as the temporary master reference serves as a slave device and continuously receives the differential correction data stream broadcast by the temporary master reference device through the ad hoc network communication module. After the differential correction data stream is parsed through the communication protocol, the following core information is included: The coordinate observation value correction amount reflects the systematic error correction value calculated by the temporary master reference device through high-quality observation data; The covariance matrix represents the accuracy characteristics of the coordinate observation value correction amount and the error correlation between different observation values.

[0089] The master unit of the slave device performs data fusion on the received differential correction data and the original pseudo-range observation value and carrier phase observation value output by the Beidou positioning module in real time, and performs carrier phase real-time kinematic positioning calculation. The calculation process is based on the spatial correlation between the temporary master reference and the slave device, effectively eliminating common errors such as satellite orbit error, satellite clock error, ionospheric delay, and tropospheric delay. The master unit utilizes the high-precision characteristics of the carrier phase observation value, detects and repairs the cycle slip, determines the integer ambiguity, and combines the differential correction amount to constrain the observation equation, and finally outputs the device coordinates with centimeter-level accuracy after differential correction.

[0090] The method for sending the corrected coordinates and device operation state data through the Beidou short message function comprises: The main control unit of the signal booster encapsulates and prioritizes the data to be sent; Device fault alarm information and coordinate anomaly data are marked as high priority, and regular state monitoring data are marked as low priority; The Beidou short message module dynamically allocates communication resources according to the priority of the data, and preferentially sends high-priority data; After receiving the data, the remote operation and maintenance platform parses the corrected coordinates and device operation state data according to the embedded protocol.

[0091] The main control unit of the signal booster organizes and encapsulates the corrected coordinates and device operation state data. Data encapsulation follows a specific application layer protocol format, and the corrected coordinates, device operation state parameters, and device identification information are packaged into a transmission frame that meets the communication requirements of the Beidou short message.

[0092] During encapsulation, the main control unit executes a priority scheduling mechanism: Device fault alarm information and coordinate anomaly data are marked as high priority; Regular state monitoring data are marked as low priority.

[0093] The Beidou short message module dynamically manages communication resources according to the priority of the data: High-priority data is preferentially allocated communication time slots and power resources; When communication resources are tight, low-priority data is temporarily suspended to ensure timely transmission of high-priority data.

[0094] After receiving the Beidou short message, the remote operation and maintenance platform parses the data frame according to the pre-set communication protocol, extracts the device identification, corrected coordinates, and operation state information, and realizes remote monitoring and operation and maintenance management of the device.

[0095] The differential correction process improves the positioning accuracy of the device, and the intelligent priority scheduling mechanism ensures the reliable transmission of critical monitoring data in a low-bandwidth Beidou short message channel, achieving high-precision positioning and reliable state monitoring of the device in a railway line scenario without public network coverage.

[0096] Embodiment 2 As shown in Figure 2 The Beidou integrated positioning-based railway signal booster ad hoc network management system comprises: A positioning module comprising a signal receiving unit and a coordinate calculation unit, wherein the signal receiving unit is used to receive Beidou satellite signals, and the coordinate calculation unit calculates the initial coordinates of the device through real-time calculation of the satellite signals in a single-point positioning mode. a signal detection module, including a level collection unit and a packet loss rate calculation unit, wherein the level collection unit collects the radio frequency signal level from the ground control base station in real time, and the packet loss rate calculation unit calculates the transmission packet loss rate of the data packet; a mode control module, including a threshold comparison unit and a mode trigger unit, wherein the threshold comparison unit compares the collected signal level with the first preset threshold and the packet loss rate with the second preset threshold, and the mode trigger unit triggers the differential relay mode when any condition is met; an ad hoc network communication module, including a data packaging unit and a multi-hop transmission unit, wherein the data packaging unit packages the original observation value and the differential quality factor into a data packet, and the multi-hop transmission unit transmits the data in the ad hoc network link in a multi-hop broadcast manner through the IEEE 802.15.4g protocol; a reference election module, including a factor aggregation unit and an algorithm solving unit, wherein the factor aggregation unit collects the differential quality factors of the neighboring devices, and the algorithm solving unit selects a temporary master reference by using the differential quality factors as the input weight through the weighted least squares algorithm; a differential correction module, including a data receiving unit and an RTK solving unit, wherein the data receiving unit receives the differential correction data sent by the temporary master reference, and the RTK solving unit performs real-time dynamic differential positioning solution based on the carrier phase observation value and outputs the correction coordinates with centimeter-level precision; a data backhaul module, including a priority scheduling unit and a short message communication unit, wherein the priority scheduling unit marks the fault alarm and the abnormal coordinate data as high priority, and the short message communication unit sends the data to the remote operation and maintenance platform through the Beidou BD-2 short message protocol; a master control module, including a flow control unit and a collaborative management unit, wherein the flow control unit coordinates the working time sequence of each module, and the collaborative management unit processes the device role configuration and network state maintenance.

[0097] It is important to note that the construction and arrangement of the application shown in the various exemplary embodiments is illustrative only. Although only two embodiments have been described in detail in this disclosure, those skilled in the art who review the disclosure will readily appreciate that many modifications are possible in the unique design, arrangement, and operations of the mechanisms, methods, compositions, and processes described herein without materially departing from the novel teachings and advantages of the subject matter described herein. For example, dimensions, sizes, shapes, and proportions of the various elements, materials, and combinations thereof, and parameters (e.g., temperatures, pressures, etc.) are not intended to be limiting, and any should be understood as exemplary only. Colors could be different from what is described. The same or equivalent elements and / or features might also have different capitalization and / or numbering from what is described herein, and they might do so without having materially changed the nature of the described technology. Thus, all such modifications are intended to be included within the scope of the present application. The order or sequence of any process or method steps can be varied or re-sequenced without materially affecting the nature of the subject matter described herein. Any reference to claim interpretation includes use of terms such as "means" for performing a function. Other substitutions, modifications, changes, and omissions can also be made in the design, operating conditions, and arrangement of the exemplary embodiments without materially departing from the novel teachings and advantages of the described technology. Therefore, the application is not limited to particular embodiments described, but extends to all substitutions and changes that fall within the scope of the following claims.

[0098] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of an actual implementation can be described (that is, those not pertinent to the best mode for carrying out the application as currently contemplated, or those not necessary enough under the circumstances to warrant specific description).

[0099] It is understood that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions can be made. Such development efforts might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

[0100] It should be noted that the above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application, and although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalent replaced without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A self-organizing network management method for railway signal boosters based on BeiDou fusion positioning, characterized in that, include: The signal booster receives BeiDou satellite signals and calculates its own initial coordinates. The signal booster monitors communication signals from the ground control base station. When the communication signal level is lower than a first preset threshold or the data packet loss rate is higher than a second preset threshold, it triggers the differential relay mode. In the differential relay mode, the multiple signal enhancers exchange their respective differential quality factors through an ad hoc network link; Based on the differential quality factor, one of the multiple signal enhancers is selected as a temporary master reference. The selection is carried out by a weighted least squares algorithm with the differential quality factor of each device as the input weight. The signal enhancer that was not elected as the temporary master reference receives the differential correction data sent by the temporary master reference and uses the data to correct its own initial coordinates. Each signal booster sends the corrected coordinates and equipment operating status data to the remote operation and maintenance platform via the BeiDou short message function.

2. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 1, characterized in that: The method by which the signal enhancer receives BeiDou satellite signals and calculates its own initial coordinates includes: The signal enhancer receives satellite signals from the BeiDou Navigation Satellite System via the BeiDou positioning module; The satellite signal is processed in real time using a single-point positioning mode, and the initial coordinates of the satellite itself, including longitude, latitude and elevation, are output.

3. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 1, characterized in that: The signal booster uses a preset signal detection module to acquire in real time the radio frequency signal level of the communication link with the ground control base station and the packet loss rate of data packets. The conditions for triggering the differential relay mode are as follows: when the radio frequency signal level is lower than the first preset threshold, it indicates a deterioration in the wireless channel quality; when the data packet loss rate is higher than the second preset threshold, it indicates a decrease in network connectivity.

4. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 3, characterized in that: When the quality of the direct communication link between the signal booster and the ground control base station deteriorates, a cooperative working mode is triggered by a single signal booster and constructed between multiple adjacent signal boosters through self-organizing network links. In differential relay mode, each signal enhancer interacts to locate differential data through the ad hoc network link, and generates a temporary master reference through dynamic election. The temporary master reference is then used to provide differential correction data to other slave devices in the network.

5. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 4, characterized in that: The signal enhancer periodically exchanges data packets within the self-organizing network link in a multi-hop broadcast manner through its self-organizing network communication module. The data packets contain its own raw pseudorange observations, carrier phase observations, and differential quality factors. During the dynamic election process, each signal enhancer aggregates the differential quality factors of all neighboring devices through the self-organizing network link; Each signal enhancer independently runs a weighted least squares algorithm, using the differential quality factor as input weights, to evaluate the suitability of each device as a potential benchmark. The algorithm takes maximizing the overall cooperative positioning accuracy of the network after differential correction as the objective function, and solves iteratively through a distributed consensus mechanism to finally elect a unique temporary master reference.

6. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 1, characterized in that: The differential quality factor is a comprehensive evaluation value, which is obtained by the main control unit of the signal enhancer based on the real-time output of its Beidou positioning module. The calculation parameters include the signal-to-noise ratio weighted average of the satellite signal, the phase noise variance of the carrier phase-locked loop, and the geometric distribution accuracy factor of the currently visible satellites. The interactive differential quality factor is encapsulated and broadcast as a necessary field of the data packet in the self-organizing network link, and a digital signature is attached.

7. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 6, characterized in that: The process of selecting the signal enhancers that were not elected as the temporary master reference is dynamic and distributed: After the weighted least squares algorithm completes the election, the temporary master reference broadcasts a reference announcement message, including a unique device identifier, through the ad hoc network link. Upon receiving the baseline announcement message and finding that its own identifier does not match the announcement identifier, the signal amplifier configures itself as a slave device and initiates a listening session for receiving differential correction data. If any signal booster does not receive the reference announcement message within a preset time, it is determined that a partition has occurred in the current network, and the election process of the temporary primary reference is retried within the network partition in which it is located.

8. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 1, characterized in that: The method for correcting its initial coordinates using the differential correction data includes: The slave device receives differential correction data from the temporary master reference; The master control unit of the slave device performs real-time dynamic differential positioning calculation of the carrier phase using its own original pseudorange observations and carrier phase observations, along with the received differential correction data.

9. The self-organizing network management method for railway signal enhancers based on BeiDou fusion positioning according to claim 8, characterized in that: The method for sending the corrected coordinates and equipment operating status data via the BeiDou short message function includes: The main control unit of the signal amplifier encapsulates and prioritizes the data to be transmitted. Equipment fault alarm information and abnormal coordinate data are marked as high priority, while routine status monitoring data are marked as low priority; The BeiDou short message module dynamically allocates communication resources based on data priority, prioritizing the transmission of high-priority data; After receiving the data, the remote operation and maintenance platform parses out the corrected coordinates and equipment operating status data according to the embedded protocol.

10. A railway signal booster self-organizing network management system based on BeiDou fusion positioning, used to implement the railway signal booster self-organizing network management method based on BeiDou fusion positioning as described in any one of claims 1-9, characterized in that, include: The positioning module includes a signal receiving unit and a coordinate calculation unit; The signal detection module includes a level acquisition unit and a packet loss rate statistics unit; The mode control module includes a threshold comparison unit and a mode triggering unit, wherein the threshold comparison unit compares the acquired signal level with a first preset threshold and the packet loss rate with a second preset threshold, and the mode triggering unit triggers the differential relay mode when any condition is met; The ad hoc network communication module includes a data encapsulation unit and a multi-hop transmission unit. The data encapsulation unit encapsulates the original observations and differential quality factors into data packets, and the multi-hop transmission unit transmits data in the ad hoc network link in a multi-hop broadcast manner through a protocol. The benchmark election module includes a factor aggregation unit and an algorithm calculation unit. The factor aggregation unit collects the differential quality factors of neighboring devices, and the algorithm calculation unit elects a temporary master benchmark by using the differential quality factors as input weights through a weighted least squares algorithm. The differential correction module includes a data receiving unit and an RTK calculation unit; The data feedback module includes a priority scheduling unit and a short message communication unit; the main control module includes a process control unit and a collaborative management unit.

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