Vehicle positioning management system based on RTCM forwarding server

Abstract

The invention discloses a vehicle positioning management system based on an RTCM forwarding server side, and belongs to the technical field of vehicle positioning services, the vehicle positioning management system comprises a vehicle side module, a server side module and an external association module, the vehicle side module comprises a combined inertial navigation module, a vehicle side dynamic MQTT client side module and a GNSS hardware driving module; the server module comprises a server static MQTT client module, a server dynamic MQTT client module, a vehicle state machine management module, a vehicle state and account resource management module and an exception handling module; when the vehicle positioning management system based on the RTCM forwarding server side works, the vehicle side module generates GPGGA data, the server side module obtains an RTK account number, the server side module is connected with the NTRIP server module, the NTRIP server module calculates RTCM return, finally, the server side module issues the RTCM to the vehicle side module, GNSS hardware is driven to calculate positioning, the server side module monitors the state and releases an idle account number, and the vehicle side module forwards the server side to the vehicle side module. And the vehicle state machine management module realizes unified management of vehicle connection and allocates NTRIP resources as required.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle positioning service, in particular to a vehicle positioning management system based on RTCM forwarding server. BACKGROUND

[0002] Vehicle high-precision positioning is the core foundation of realizing high-level automatic driving and intelligent transportation. Vehicle high-precision positioning can provide centimeter-level positioning accuracy for high-level automatic driving, ensuring accurate decision-making of vehicles in complex road conditions, and also helping traffic management systems to master the dynamics of each vehicle in real time, enabling dynamic lane regulation, intelligent signal timing, and having important significance for ensuring safe travel, improving traffic efficiency, and reducing traffic accidents. When a vehicle is performing high-precision positioning, a vehicle high-precision positioning system needs to be used. For example, the automatic driving vehicle high-precision positioning system, method, medium, and device disclosed in Chinese patent application No. 202411431213.X, filed on October 14, 2024, includes the following steps: S1, receiving the Bluetooth signal emitted by the vehicle through the AOA module and calculating the angle of arrival of the signal; S2, combining the angle of arrival with the vehicle position information provided by the GPS module to obtain the position prediction; S3, emitting laser pulses through the laser radar module and receiving the reflected signals to obtain the point cloud data of the surrounding environment; S4, comparing the point cloud data with the prior positioning map to determine the grid number where the vehicle is located, and obtaining the positioning result through online normal distribution transformation; S5, based on the information provided by the GPS module and the inertial module, the calculation module optimizes the positioning result to obtain the precision positioning result. It works stably and accurately even in underground scenarios, improves positioning accuracy, reduces computing resource requirements, adapts to complex environments, and reduces dependence on initial position. Another example is the high-precision vehicle positioning system and method based on modified lane lines disclosed in Chinese patent application No. 201711092897.5, filed on November 8, 2017. When it works, the vehicle-mounted camera captures pictures of the current position of the vehicle, and the pictures contain modified lane lines that are different from ordinary lane lines. The WiFi receiver receives WiFi data at the current position of the vehicle, which is composed of WiFi signals emitted by AP base stations set at intervals along the positioning road section. The processor and the memory have pre-stored high-precision visual maps of the positioning road section, which contain WiFi data and image data of each interval position, two-dimensional position data and coding of each modified lane line, and pictures containing modified lane lines and their image feature data taken at each interval. The memory stores a computer program that can be called. After preliminary positioning by WiFi, it adds modified lane line detection, image-level positioning, and measurement-level positioning to achieve precise positioning. The modification cost is low, and high-precision vehicle positioning is realized even in situations where GPS signals cannot be received.6. A Chinese patent application filed on March 18, 2021, describes a remote vehicle control system and its control device based on 5G communication and high-precision positioning. It includes a lidar, a high-definition camera, a high-precision positioning antenna, a sound-controlled radar, a millimeter-wave radar, a vehicle, a satellite, a latency detection device, a 5G base station, a control device, a test bench, and a host computer. The control device includes a chassis, a first gear, a second gear, a motor, a signal receiving module, a support rod, a first connecting rod, a second connecting rod, a third connecting rod, and a first hydraulic cylinder. During operation, it seamlessly integrates information from the cloud, roads, and vehicles by utilizing digital and information resources. Employing technologies such as parallel vision and perception, parallel learning, parallel planning, and parallel control, it connects remote vehicles, a management platform, and a driving simulator in real time, making the remote vehicle's movement measurable and controllable. This improves the vehicle system's rapid response to the environment, reduces overall system costs, and achieves vehicle-road interaction, multi-vehicle collaboration, parallel control, and safe driving.

[0003] However, existing high-precision vehicle positioning systems typically employ RTK (Real-Time Dynamic Differential) technology, correcting positioning errors by receiving differential data from a base station. Each vehicle connects independently to an NTRIP server, lacking a vehicle connection status monitoring mechanism. Furthermore, while operating, the system loads fixed account information when connected to the NTRIP server, and continues to occupy RTK accounts even when idle, resulting in low resource utilization. The lack of a vehicle connection status monitoring mechanism also prevents real-time responses to changes in vehicle status (such as reconnection after disconnection), leading to poor dynamic adaptability. Therefore, we propose a vehicle positioning management system based on an RTCM forwarding server to address the aforementioned problems. Summary of the Invention

[0004] The purpose of this invention is to provide a vehicle positioning management system based on an RTCM forwarding server to solve the problems mentioned in the background art, such as connecting to an NTRIP server to load fixed account information, still occupying RTK accounts when idle, low resource utilization, lack of vehicle connection status monitoring mechanism, inability to respond to changes in vehicle status in real time (such as disconnection and reconnection), and poor dynamic adaptability.

[0005] In order to achieve the above object, the present application provides the following technical scheme: a vehicle positioning management system based on an RTCM forwarding server end, comprising a vehicle end module, a server end module and an external association module, the vehicle end module comprising a combined inertial navigation module, a vehicle end dynamic MQTT client module and a GNSS hardware driving module, the vehicle end module being responsible for collecting and processing positioning data, transmitting the positioning data to the server end and receiving differential data, and driving the hardware to solve the positioning; the server end module comprising a server end static MQTT client module, a server end dynamic MQTT client module, a vehicle state machine management module, a vehicle state and account resource management module and an exception processing module, the server end module being responsible for unified management of vehicle connection and account, forwarding data, monitoring state and processing exceptions to ensure positioning when working; the external association module comprising an NTRIP server module, which receives GPGGA data from the server end, generates RTCM data through differential solution and returns the RTCM data, thereby supporting high-precision positioning.

[0006] Preferably, the combined inertial navigation module is responsible for collecting vehicle positioning raw data, splicing and processing the raw data into GPGGA data in NMEA format, completing preprocessing of the positioning basic data and providing basic data support for positioning calculation of the GNSS hardware driving module.

[0007] The combined inertial navigation module provides positioning data (GPGGA data) meeting the format requirements for the vehicle end module, and supports the GNSS hardware driving module to solve high-precision positioning information through receiving RTCM data, thereby ensuring implementation of the high-precision positioning function of the vehicle.

[0008] Preferably, the vehicle end dynamic MQTT client module undertakes the function of data transmission, sends the GPGGA data processed by the combined inertial navigation module to the server end through the MQTT protocol, realizes basic data transmission from the vehicle end module to the server end module, and receives the RTCM data issued by the server end module and transmits the RTCM data to the combined inertial navigation module.

[0009] The vehicle end dynamic MQTT client module realizes efficient interaction of real-time differential data (GPGGA data and RTCM data) between the vehicle end and the server end through the dynamic channel of the double-channel MQTT communication architecture, provides stable data transmission support for high-precision positioning of the vehicle, and improves the pertinence and reliability of positioning data transmission in the multi-vehicle scene in cooperation with the server end module.

[0010] Preferably, the GNSS hardware driving module receives the RTCM data transmitted by the combined inertial navigation module, corrects the positioning error in combination with the RTCM differential data, drives the GNSS hardware to operate, and finally calculates the high-precision positioning information of the vehicle.

[0011] The GNSS hardware driving module comprises GNSS hardware, and the GNSS hardware driving module is a core execution unit of vehicle-side high-precision positioning, can eliminate positioning errors by using RTCM differential data, can ensure that the GNSS hardware can stably output high-precision position information meeting requirements, and can provide key hardware driving support for implementation of a vehicle positioning function.

[0012] The whole vehicle-side module realizes efficient processing of raw data, real-time differential data interaction with the server-side module, and driving of GNSS hardware to output high-precision positioning information through cooperation of the inertial navigation module, the vehicle-side dynamic MQTT client module and the GNSS hardware driving module, finally provides accurate and stable positioning capability for vehicles, guarantees positioning requirements of vehicles in complex scenes, and is a core execution unit of implementation of a vehicle high-precision positioning function.

[0013] Preferably, the server-side static MQTT client module is specially used for obtaining configuration information by interacting with the outside, requesting an RTK account, a password and a mounting point and the like from the outside, and feeding back an account abnormality to the outside and requesting a new account when the NTRIP server module connection is abnormal.

[0014] The server-side static MQTT client module establishes a link with the server-side module, requests an RTK account, a password and a mounting point and the like from the outside, supports the server-side to connect the NTRIP server module after obtaining a valid account, receives account abnormality information fed back by the server-side module when the NTRIP server module connection is abnormal, and requests a new RTK account to help rebuild the NTRIP connection, has the beneficial effects of realizing reliable transmission of RTK account configuration information relying on a static channel of a double-channel MQTT communication architecture, providing key support for the server-side module to obtain an account and handle account abnormalities, and solving the problem of low efficiency of account resource management in the prior art in cooperation with other modules, and guaranteeing stable establishment of the NTRIP connection in a multi-vehicle scene.

[0015] Preferably, the server-side dynamic MQTT client module realizes data interaction with the vehicle-side module, receives GPGGA data sent by the vehicle-side module, and simultaneously sends RTCM data obtained by solving the NTRIP server module to the vehicle-side module to trigger a differential data solving process, and needs to cooperate with the vehicle state and account resource management module to adjust a data transmission strategy according to a vehicle connection state, and the server-side static MQTT client module and the server-side dynamic MQTT client module form a dynamic channel of a double-channel MQTT communication architecture.

[0016] The above-mentioned server dynamic MQTT client module, after initialization, receives the GPGGA data sent by the vehicle end module, maintains an independent NTRIP session and a differential data processing thread for each vehicle, forwards the GPGGA data to the NTRIP server module for calculation, and then obtains the RTCM differential data and sends it to the vehicle end module. In addition, it also cooperates with the server module to regularly poll the vehicle connection and RTK account status, adjusts the data transmission according to the vehicle activity (such as stopping the delivery if the vehicle has not reported data for a long time), and has the beneficial effect of relying on the dynamic channel of the double-channel MQTT communication architecture to realize efficient interaction of real-time differential data between the vehicle end module and the server module, the server module and the NTRIP server module, ensuring the independence and timeliness of multi-vehicle data processing, and improving the utilization rate of RTK accounts and the dynamic adaptability of the system with the resource management module.

[0017] Preferably, the vehicle state machine management module maintains an independent NTRIP session for each vehicle connected to the system, and creates a corresponding differential data processing thread to ensure that the positioning data processing process of each vehicle is independent and efficient, avoiding data confusion or delay. The NTRIP server module transmits the returned RTCM data to the server dynamic MQTT client module through the MQTT protocol.

[0018] The above-mentioned vehicle state machine management module, after initialization of the server dynamic MQTT client module, maintains an independent NTRIP session for each connected vehicle, interacts with the NTRIP server module through the established Socket data channel, and creates a dedicated differential data processing thread to receive vehicle GPGGA data and forward it to the NTRIP server module for calculation, and then sends the RTCM differential data to the corresponding vehicle end. Its beneficial effect is to allocate an independent session and thread for each vehicle to ensure that multi-vehicle data processing does not interfere with each other, ensuring the independence and timeliness of differential data transmission and calculation, and improving the efficiency and stability of NTRIP connection management in a multi-vehicle scenario with the server state monitoring mechanism.

[0019] Preferably, the vehicle state and account resource management module integrates vehicle state machine management and RTK account management functions, monitors vehicle connection status in real time, detects vehicle activity regularly, and releases idle RTK accounts. It also manages the acquisition, allocation and recovery of RTK accounts.

[0020] The vehicle state and account resource management module relies on the mechanism of the vehicle state machine management module to monitor the vehicle connection state in real time, polls the vehicle activity (based on the GPGGA data reporting situation) at regular intervals, and closes the connection and releases the corresponding RTK account resource if the vehicle has not reported data for a long time. At the same time, when the NTRIP server module connection is abnormal, the service module feeds back the account exception to the service static MQTT client module, re-requests a new RTK account to rebuild the connection, and coordinates the acquisition, allocation and recovery of RTK accounts. The beneficial effects are to solve the problems of low utilization rate of RTK account resources and lack of vehicle state monitoring in the prior art, to realize on-demand allocation and dynamic management of account resources in a multi-vehicle scenario, and to improve the response capability of the system to vehicle state changes and resource utilization efficiency.

[0021] Preferably, the abnormality processing module monitors the connection state of the NTRIP server module, triggers the account exception feedback and new account request process when the connection is abnormal, rebuilds the NTRIP connection, and ensures the continuous and stable operation of the system.

[0022] The abnormality processing module is actually realized by the service module, and the workflow is as follows: the service module monitors the connection state of the NTRIP server module at regular intervals, and if the connection is abnormal (such as interruption of the Socket data channel, inability to obtain RTCM data), it feeds back the account exception to the service static MQTT client module and re-requests a new RTK account to rebuild the NTRIP connection. At the same time, the vehicle connection state is polled at regular intervals, and if a vehicle has not reported GGA data for a long time, it is determined to be abnormal and its connection is closed, releasing the corresponding RTK account resource. The beneficial effects are to respond to the abnormal state of the NTRIP server module and the vehicle module in real time, to avoid positioning service interruption caused by abnormalities by re-acquiring accounts and releasing idle resources, to improve the dynamic adaptability and stability of the system, and to ensure efficient use of RTK account resources and continuity of positioning services in a multi-vehicle scenario.

[0023] The entire service module, under the synergistic action of the internal modules, realizes efficient acquisition and dynamic management of RTK accounts, independent processing and real-time forwarding of multi-vehicle differential data, and automatic reconnection and resource recovery capability in abnormal state, improving the utilization rate of RTK account resources and the stability of the system, and is the core control and data hub of multi-vehicle high-precision positioning services.

[0024] Preferably, the NTRIP server module in the external association module receives the GPGGA data forwarded by the dynamic MQTT client module in the service module, uses the RTK technology to perform differential solution on the data, generates RTCM differential data for correcting positioning errors, and then returns the RTCM data to the vehicle state machine management module in the service module through a Socket channel.

[0025] The NTRIP server module receives the GPGGA data of the vehicle end module transmitted by the service module through a Socket data channel, performs differential solution on the data to generate RTCM differential data, and returns the RTCM differential data to the service module. When the service module requests to establish a connection, identity verification is completed based on the RTK account provided by the service module, and a data interaction channel is established. If an abnormal connection occurs, the service module will request the RTK account again to rebuild the connection. The beneficial effect is that as the core unit of differential solution, the RTCM data required for positioning error correction is generated by processing the GPGGA data of the vehicle end, which provides key differential data support for high-precision positioning of vehicles. At the same time, the service module completes account verification and connection management, ensuring the accuracy and continuity of positioning data solution in a multi-vehicle scenario.

[0026] Compared with the prior art, the beneficial effects of the present application are: 1. A new structure design is adopted, and through the multi-vehicle dynamic connection pool technology and the vehicle state machine management module, unified management of vehicle connection is realized, vehicle activity is detected regularly, idle RTK account resources are released, long-term occupation of accounts is avoided, RTK account resource utilization is greatly improved, and the problem of resource waste in the prior art is improved; 2. Relying on the communication architecture of the service end static MQTT client module and the service end dynamic MQTT client module, the service end static MQTT client module transmits account configuration, and the service end dynamic MQTT client module transmits real-time differential data, ensuring the pertinence and efficiency of data transmission, and cooperating with the service end to maintain independent NTRIP sessions and differential data processing threads for each vehicle, ensuring that multiple vehicle data processing does not interfere with each other; 3. Real-time monitoring of vehicle connection state and NTRIP server module connection state can automatically trigger disconnection and reconnection, account exception feedback and re-request, real-time response to vehicle and server state changes, improve system dynamic adaptability, and finally realize efficient management of NTRIP connection in a multi-vehicle scenario and stable and high-precision positioning service, and the specific content is as follows: (1) The vehicle positioning management system based on the RTCM forwarding server, when working, the vehicle end module generates GPGGA data, then the server module obtains the RTK account, the server module connects the NTRIP server module, the NTRIP server module calculates the RTCM return, and finally the server module issues the RTCM to the vehicle end module to drive the GNSS hardware to calculate the positioning, the server module monitors the state and releases the idle account, the vehicle state machine management module realizes the unified management of vehicle connection, allocates NTRIP resources on demand, avoids the idle of RTK account, improves the resource utilization rate, cooperates with state monitoring and abnormal processing, ensures the stability of positioning service, and enhances the dynamic adaptability of the system.

[0027] (2) The vehicle positioning management system based on the RTCM forwarding server sets the server static MQTT client module and the server dynamic MQTT client module, wherein the server static MQTT client module is specially used for transmitting RTK account, password and mounting point and the like configuration information, avoiding mixed transmission of account data and real-time difference data, reducing the risk of interference or leakage of configuration information, at the same time, focusing the account request and feedback, ensuring that the server can quickly obtain effective account, laying a stable foundation for subsequent connection of the NTRIP server module, at the same time, the server dynamic MQTT client module dynamically transmits GPGGA (vehicle end original data) and RTCM (difference data) through a dynamic channel, which can preferentially ensure the transmission efficiency of real-time positioning data, reduce the delay, ensure that the vehicle end receives the difference data in time to drive the GNSS hardware driving module to calculate high-precision positioning, and meet the real-time requirement of vehicle positioning.

[0028] Further, the two types of data are transmitted through channels and do not occupy resources, so that the influence of congestion of one type of data on the processing of another type of data can be avoided, for example, the real-time difference data transmission will not be disturbed when the account configuration is updated, further improving the running stability and reliability of the system in the multi-vehicle concurrent scene.

[0029] (3) The vehicle positioning management system based on the RTCM forwarding server can automatically trigger the reconnection mechanism when the vehicle appears disconnection and other connection abnormities, so as to quickly restore the communication link between the vehicle end module and the server module and the NTRIP server module without manual intervention, avoiding the suspension of positioning service caused by connection interruption, ensuring that the vehicle can always obtain difference data to realize high-precision positioning during driving, especially suitable for scenes with high requirements for positioning continuity (such as automatic driving and precise scheduling of vehicle fleet), and significantly improving the overall running reliability of the system.

[0030] Further, by detecting the vehicle activity in time, the vehicle state machine management can accurately identify the idle vehicle which has not reported GGA data for a long time, and timely close the corresponding connection and release the occupied RTK account resource. This mechanism effectively solves the problem that idle vehicles still occupy RTK accounts in the prior art, so that the limited RTK account resources can be allocated to active vehicles as needed, greatly improving the utilization rate of account resources, reducing the cost waste caused by idle resources, and the effect is more prominent in the scene of multiple vehicle concurrent use.

[0031] Further, the vehicle state machine management realizes the automatic monitoring and management of the vehicle connection state and account resources, without the need for manual continuous investigation of vehicle connection or manual recovery of idle accounts. Even if the number of vehicles changes dynamically (such as part of the vehicles online or offline), the system can still adjust the connection and resource allocation strategy independently, reducing the workload and error probability of manual operation and maintenance, reducing the system operation and maintenance cost, and making the system more flexible to cope with complex and variable multi-vehicle use scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0032] Fig. 1 The figure is a schematic diagram of the working process of the vehicle end module of the application. Fig. 2 The figure is a schematic diagram of the working process of the server module of the application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0034] Please refer to Figs. 1-2 The application provides the following technical solutions: a vehicle positioning management system based on an RTCM forwarding server.

[0035] The vehicle positioning management system comprises a vehicle end module, a server module and an external association module. The vehicle end module comprises a combined inertial navigation module, a vehicle end dynamic MQTT client module and a GNSS hardware driving module. The vehicle end module is responsible for collecting and processing positioning data, transmitting the positioning data to the server and receiving differential data, and driving the hardware to calculate the positioning. The combined inertial navigation module is responsible for collecting vehicle positioning raw data, and splicing and processing the raw data into GPGGA data in NMEA format, to complete the preprocessing of the positioning basic data and provide basic data support for the positioning calculation of the GNSS hardware driving module.

[0036] The above combination inertial navigation module integrates GNSS receiver and inertial measurement unit (IMU) two types of core components, collects original data through multi-source data fusion, GNSS receiver receives global navigation satellite system (such as GPS, Beidou) signal, obtains real-time position (latitude, longitude, elevation) of vehicle, satellite ephemeris, signal signal-to-noise ratio and other original data, provides absolute position reference for positioning; IMU collection: through the internal accelerometer and gyroscope, real-time collection of three-dimensional acceleration and angular velocity data of the vehicle, reflecting the motion state of the vehicle (such as acceleration, deceleration, turning, tilting), making up for the positioning interruption problem of GNSS receiver in shielding scene (such as tunnel, high-rise area); Data synchronous collection: the module is built-in time synchronization unit, the collected data of GNSS receiver and IMU are aligned according to unified timestamp, ensuring the consistency of original data in time dimension, laying foundation for subsequent fusion processing.

[0037] And when the combined inertial navigation module performs original data splicing processing, the effective fields are extracted from the GNSS receiver original data, such as UTC time (hour: minute: second, millisecond), latitude (format "degree and minute, minute decimal"), longitude (same format as latitude), positioning state (such as "0" represents not positioning, "1" represents single point positioning, "2" represents differential positioning), number of satellites participating in solution, horizontal dilution of precision (HDOP), elevation (height above sea level), etc. The extracted original data is converted according to the requirements of GPGGA format, for example, the latitude "30°30.1234" output by GNSS is converted to "3030.1234" (remove degree and minute symbol, keep "degree and minute, minute decimal" format), and add hemisphere identifier (such as "N" represents north latitude, "E" represents east longitude), then perform field splicing and verification, splice all fields according to the fixed order of GPGGA, finally calculate and add the checksum required by NMEA protocol (obtained by XOR operation on field content), form complete GPGGA data frame.

[0038] The combined inertial navigation module is the core link of vehicle end data processing, which can standardize the collected original sensor data into NMEA format GPGGA data conforming to the interaction standard, providing unified and usable basic data for subsequent data transmission with the server module; at the same time, it can receive the RTCM differential data issued by the server module and pass it to the GNSS hardware driver module, providing key data support for positioning error correction, directly ensuring the accuracy of high-precision positioning solution.

[0039] The vehicle end dynamic MQTT client module undertakes the data transmission function. On one hand, the GPGGA data processed by the integrated inertial navigation module is sent to the server end through the MQTT protocol, realizing the basic data transmission from the vehicle end module to the server end module. On the other hand, the RTCM data issued by the server end module is received and transmitted to the integrated inertial navigation module.

[0040] When the vehicle end dynamic MQTT client module sends the GPGGA data processed by the integrated inertial navigation module to the server end through the MQTT protocol, a connection needs to be established first. The vehicle end dynamic MQTT client first establishes a TCP connection with the broker of the server end static MQTT client module and the server end dynamic MQTT client module, completes identity authentication (ensuring communication security) through “username + password” or certificate, then sends an MQTT connection message (including client ID, connection time, etc.), confirms the establishment of the MQTT session with the server end module, and then the server end module obtains the processed GPGGA data from the integrated inertial navigation module, encapsulates it into a “PUBLISH message - specifies a preset “vehicle end GPGGA data upload” topic according to the MQTT protocol requirements, and sets the QoS level (usually QoS1, ensuring that the data is received by the server end at least once). Then the server end module sends the encapsulated PUBLISH message to the MQTT broker inside the server end module. If QoS1 is set, the server end will return a “PUBACK” message after receiving the data, and the client will complete the reliable sending of GPGGA data after receiving the confirmation. When the vehicle end dynamic MQTT client module receives the RTCM data issued by the server end module and transmits it to the integrated inertial navigation module, after establishing an MQTT connection with the server end module, the vehicle end dynamic MQTT client will actively send a “SUBSCRIBE message to the server end MQTT broker, specifying the “server end module RTCM data issue” topic to be received, and setting the QoS level of the topic (matching the sending end, ensuring reliable data reception). Then data reception and confirmation are performed. When the server end module issues RTCM data to the vehicle end module through the dynamic MQTT client, the server end MQTT broker will push the PUBLISH message encapsulating the RTCM data to the corresponding vehicle end module client according to the subscription relationship. After receiving the message, if the QoS is 1, the client will return a PUBACK message to the broker to confirm the reception, avoiding data loss, and finally performing data analysis and forwarding. The client analyzes the received PUBLISH message, extracts the RTCM differential data, and then forwards the data to the integrated inertial navigation module, providing support for subsequent GNSS hardware driver module to solve high-precision positioning information.

[0041] The GNSS hardware driving module receives the RTCM data transmitted by the integrated inertial navigation module, corrects the positioning error in combination with the RTCM differential data, drives the GNSS hardware to perform operation, and finally calculates the high-precision positioning information of the vehicle.

[0042] The GNSS hardware driving module and the integrated inertial navigation module usually establish a data transmission link through a preset hardware interface (such as UART, SPI or CAN bus). After receiving the RTCM differential data issued by the server, the integrated inertial navigation module will send the RTCM data frame (including differential correction information, reference station information, etc.) to the GNSS hardware driving module frame by frame according to the communication protocol agreed by both parties (such as fixed baud rate, data frame format). The driving module has a built-in data receiving buffer, which receives and temporarily stores RTCM data in real time, checks the data frame (such as checking the frame header and frame tail, checksum), filters invalid or damaged data, and ensures the integrity and validity of the received data. Then data analysis and differential information extraction are performed: the GNSS hardware driving module analyzes the received valid RTCM data frame, extracts the key differential information, including reference station coordinates, satellite ephemeris correction, ionospheric and tropospheric error correction parameters, etc. These information directly reflects the error sources of GNSS satellite signal in the propagation process. At this time, the GNSS hardware driving module transmits the extracted differential information to the hardware solving unit in the GNSS hardware driving module, and simultaneously acquires the satellite raw observation data (such as pseudorange, carrier phase) received by the GNSS hardware driving module itself. The solving unit corrects the systematic errors (such as ionospheric delay, tropospheric delay, satellite clock error) in the satellite raw observation data in real time based on the RTCM differential information, eliminates or weakens the influence of errors on the positioning results. Finally, high-precision positioning operation and result output are performed: after completing the error correction, the hardware solving unit in the GNSS hardware driving module uses the RTK (Real-Time Kinematic) solving algorithm to solve the corrected observation data, calculates the accurate distance between the satellite and the vehicle, and combines the reference station coordinates to solve the real-time three-dimensional coordinates (latitude, longitude, and elevation) of the vehicle. Finally, the GNSS hardware driving module outputs the high-precision positioning information obtained by solving in the preset format (such as NMEA protocol or custom protocol), providing position data support for subsequent applications such as navigation and control of the vehicle.

[0043] The entire vehicle-side module: through the cooperation of the integrated inertial navigation module, the vehicle-side dynamic MQTT client module and the GNSS hardware driving module, the vehicle-side module realizes efficient processing of raw data, real-time differential data interaction with the server module, and finally drives the GNSS hardware to output high-precision positioning information, providing accurate and stable positioning capability for the vehicle and ensuring the positioning needs of the vehicle in complex scenarios. It is the core execution unit for realizing the high-precision positioning function of the vehicle.

[0044] The server module includes a server static MQTT client module, a server dynamic MQTT client module, a vehicle state machine management module, a vehicle state and account resource management module, and an exception handling module. When the server module is working, it uniformly manages vehicle connection and accounts, forwards data, monitors status, and handles exceptions to ensure positioning. The server static MQTT client module is used to interact with the outside to obtain configuration information, request RTK account, password, and mounting point from the outside, and feedback account exception to the outside and request a new account when the NTRIP server module connection is abnormal.

[0045] After the server static MQTT client module is started, it first reads the system preset connection parameters (such as MQTT broker address, port, authentication information), establishes a stable connection with the specified MQTT broker through the TCP protocol. During the connection process, the server static MQTT client module sends a connection message containing the client ID and the connection time (usually set to a long period to adapt to the low frequency requirement of account configuration transmission), and completes identity authentication through "username + password" or certificate to ensure the security of communication with the broker, avoid illegal access to account configuration data, and then request and receive account configuration information. When the server needs to obtain RTK account, password, and mounting point configuration information, the server static MQTT client module sends a subscription (SUBSCRIBE) message to the MQTT broker, specifies the preset account configuration topic, and sets the QoS level (usually QoS1 to ensure reliable reception of account information). Then, the server static MQTT client module sends a publish (PUBLISH) message to the broker, carries the server identification information in the preset account configuration request topic, and triggers the response of the external account management system (such as the account server). When the external system pushes the account configuration data through the broker, the server static MQTT client module receives the corresponding PUBLISH message, parses and extracts the RTK account information, and checks the data integrity (such as checking whether the fields are complete and the format is correct). After confirming that there is no error, the account information is forwarded to the server module to provide credentials for subsequent connection to the NTRIP server module.

[0046] When the server module detects that the NTRIP server module connection is abnormal (such as authentication failure, connection interruption), and determines that the RTK account is abnormal, the module will encapsulate the exception information (such as exception type, current account ID), generate a PUBLISH message and send it to the preset account exception feedback topic, to inform the external account management system that the current account is unavailable; after the feedback is completed, the module sends an account configuration request to the broker again (repeat the request process of the second step), subscribes to the account configuration distribution topic again, and waits to receive a new valid RTK account; after the new account is received and verified, the server static MQTT client module forwards it to the NTRIP connection management unit in the server module, supports the server to rebuild the connection with the NTRIP server module, and restores the differential data processing process.

[0047] The server dynamic MQTT client module realizes data interaction with the vehicle module, receives the GPGGA data sent by the vehicle module, and at the same time distributes the RTCM data obtained after the NTRIP server module is solved to the vehicle module, triggering the differential data solving process; at the same time, it also needs to cooperate with the vehicle state and account resource management module to adjust the data transmission strategy according to the vehicle connection state. The server static MQTT client module and the server dynamic MQTT client module form a dynamic channel of the double-channel MQTT communication architecture.

[0048] When the server dynamic MQTT client module receives the GPGGA data of the vehicle module, the server dynamic MQTT client module relies on the dynamic channel in the "double-channel MQTT communication architecture" to establish a dedicated data interaction link with the vehicle dynamic MQTT client module. This channel is specially used for transmitting real-time differential related data, and provides stable channel support for high-frequency data interaction between the vehicle module and the server module. After the server dynamic MQTT client module is started, the server dynamic MQTT client module will initialize and listen to the preset vehicle module GPGGA data upload topic, waiting for the vehicle module data to be sent. When the NMEA format GPGGA data processed by the integrated inertial navigation module is sent to the topic through the vehicle dynamic MQTT client module, the server dynamic MQTT client module receives the data in real time and performs preliminary verification on the data integrity (such as checking whether the GPGGA data format conforms to the NMEA protocol specification), and after confirming that there is no error, the data is transmitted to the differential data processing link inside the server module, preparing for subsequent forwarding to the NTRIP server module for solving; When the server dynamic MQTT client module issues RTCM data, the vehicle state machine management module of the server module cooperates with the differential data processing thread (relying on the dynamic MQTT client module) to forward the GPGGA data of the vehicle module to the NTRIP server module. After the NTRIP server module completes differential calculation to generate RTCM data, the server dynamic MQTT client module receives the RTCM data. Subsequently, the server dynamic MQTT client module encapsulates the RTCM data into an MQTT protocol message according to a preset server RTCM data issuing topic (a directional push topic agreed with the vehicle), and issues the RTCM data to the vehicle dynamic MQTT client module. After the vehicle module receives the RTCM data, the RTCM data is transmitted to the integrated inertial navigation module, which in turn drives the GNSS hardware to start the differential data calculation process, and finally obtains high-precision positioning information, completing a complete differential data interaction closed loop. When the server dynamic MQTT client module cooperates with the vehicle state and account resource management module, the vehicle state and account resource management module periodically polls the connection states (such as whether online or whether long time without reporting GGA data) and RTK account states of all vehicles, and synchronizes the monitoring results to the server dynamic MQTT client module. If it is monitored that a vehicle has not reported GGA data for a long time, it is determined that the vehicle connection is abnormal or idle. The vehicle state and account resource management module triggers the instruction of "closing the vehicle connection and releasing the RTK account resource". After the server dynamic MQTT client module receives the instruction, it immediately stops issuing RTCM data to the vehicle, avoiding invalid data transmission to occupy resources. If it is monitored that the NTRIP server module connection is abnormal, the vehicle state and account resource management module feeds back the account abnormality and requests a new RTK account. The server dynamic MQTT client module will pause data issuing to the corresponding vehicle. After the new RTK account is obtained and the NTRIP server module connection is rebuilt, the RTCM data issuing is restored, ensuring the effectiveness of data transmission and the stability of the system.

[0049] The vehicle state machine management module maintains an independent NTRIP session for each vehicle connected to the system, and simultaneously creates a corresponding differential data processing thread, ensuring that the positioning data processing process of each vehicle is independent and efficient, avoiding data confusion or delay. At the same time, the NTRIP server module transmits the returned RTCM data to the server dynamic MQTT client module through the MQTT protocol.

[0050] The vehicle state machine management module: after the service end dynamic MQTT client module is initialized, a unique identifier (such as a vehicle ID) is allocated for each vehicle connected to the system. After the service end static MQTT client module obtains valid RTK account information and connects to the NTRIP server module, an independent NTRIP session is established for each vehicle based on the vehicle unique identifier, that is, a dedicated data link is established between the Socket data channel and the NTRIP server module, ensuring that the GPGGA data transmission and RTCM data reception of each vehicle do not interfere with each other, and realizing independent management of the session. The vehicle state machine management module creates corresponding differential data processing threads: at the same time as establishing an independent NTRIP session for the vehicle, the service end dynamic MQTT client module simultaneously creates corresponding differential data processing threads for the vehicle. These threads are responsible for processing the GPGGA data and RTCM data of the vehicle: on the one hand, they receive GPGGA data sent by the vehicle end through the service end dynamic MQTT client module and forward it to the NTRIP server module for differential calculation; on the other hand, they receive RTCM differential data calculated by the NTRIP server module and then send it to the corresponding vehicle end module through the service end dynamic MQTT client module, ensuring that the data processing process of each vehicle is independent and efficient, and avoiding mutual blocking of multi-vehicle data processing.

[0051] The vehicle state and account resource management module integrates vehicle state machine management and RTK account management functions, and monitors vehicle connection status and detects vehicle activity in real time, releasing idle RTK accounts. It also manages the acquisition, allocation, and recovery of RTK accounts.

[0052] When monitoring vehicle connection status and detecting vehicle activity, the vehicle state and account resource management module needs to rely on the management mechanism of the vehicle state machine management module to monitor the connection status of the vehicle module and the service end module (such as whether it is online and whether data is transmitted normally), and to detect vehicle activity at a predetermined period. The core judgment basis is whether the vehicle end reports GPGGA data. If a vehicle has not reported data for a long time, it is determined to be in an abnormal connection or idle state. Release of idle RTK accounts: when a vehicle is detected to be idle or in an abnormal connection, the vehicle state and account resource management module immediately triggers the account recovery process, closes the NTRIP connection corresponding to the vehicle, releases the RTK account resources occupied by the vehicle, and ensures that the account can be allocated to other active vehicles, avoiding resource idling. The management of RTK account acquisition, allocation and recovery: the vehicle state and account resource management module cooperates with the server static MQTT client module, when a new vehicle accesses or the original account is abnormal, triggers the RTK account acquisition request, requests the RTK account, password and mounting point information from the outside through the server static MQTT client module, allocates the account to the active vehicle to be accessed according to the "on-demand allocation" principle after obtaining the valid account, supports the establishment of NTRIP connection, if the NTRIP server module connection is abnormal (such as identity verification failure), the vehicle state and account resource management module determines that the RTK account is abnormal, immediately feeds back the account abnormal information to the outside through the server static MQTT client module, and reinitiates the account request, and reallocates the vehicle after obtaining a new account, to ensure the effectiveness of the RTK account use and the continuity of the system positioning service.

[0053] The abnormal processing module monitors the connection state of the NTRIP server module, and when the connection is abnormal, triggers the account abnormal feedback and new account request process, and rebuilds the NTRIP connection to ensure the continuous and stable operation of the system.

[0054] When the above abnormal processing module monitors the connection state of the NTRIP server module, the server module connects the NTRIP server module through the RTK account and establishes a Socket data channel, and then detects the communication state of the Socket data channel (such as whether it can normally receive the vehicle end GPGGA data and whether it can obtain the RTCM differential solution data from the NTRIP server), judges whether the connection of the NTRIP server module is normal, when the Socket data channel is interrupted, the RTCM data feedback by the NTRIP server module is not received for a long time, or there is no response after sending the GPGGA data to the NTRIP server module, etc., it is determined that the connection of the NTRIP server module is abnormal, at this time, the server module will feedback the account abnormal information to the outside through the server static MQTT client module, and request a new RTK account, and rebuild the connection with the NTRIP server module based on the new account, so as to complete the monitoring and processing of the NTRIP server module connection exception.

[0055] The external association module includes the NTRIP server module, when working, the external association module receives the service end GPGGA data, generates RTCM data through differential solution and returns, and supports high-precision positioning.

[0056] The NTRIP server module in the external association module receives the GPGGA data forwarded by the dynamic MQTT client module in the server module, uses the RTK technology to perform differential solution on the data, generates RTCM differential data for correcting positioning error, and then returns the RTCM data to the vehicle state machine management module in the server module through the Socket channel.

[0057] The NTRIP server module needs to receive two core data when working, one is the observation data of the reference station (real-time collected by the fixed position GNSS reference station, including satellite pseudorange, carrier phase, reference station accurate coordinates, observation timestamp, etc.), and the other is the observation data of the vehicle end module (i.e. the GPGGA data of the vehicle end module forwarded by the server module, including the vehicle end GNSS original observation value, rough position, satellite number participating in solving, etc.). The NTRIP server module pre-processes the two types of data, aligns them by timestamp (ensures that the data is compared under the same time dimension), and checks the data integrity (filters invalid or missing observation values), laying a foundation for subsequent differential solution. When the NTRIP server module performs differential solution of RTK technology, error separation is needed. The core of RTK technology is to eliminate systematic errors in the propagation process of GNSS signals. The NTRIP server module compares the observation data of the reference station and the vehicle end module to separate the error items common to both types of data, including ionospheric delay error, tropospheric delay error, and satellite clock error and orbit error. The ionospheric delay error is the propagation delay caused by electronic interference when the satellite signal passes through the ionosphere. When the reference station and the vehicle end are in the same region, this error has strong correlation. The tropospheric delay error is the delay caused by the change in atmospheric density when the signal passes through the troposphere, which can also be corrected by modeling the reference station data. The satellite clock error and orbit error are the satellite's own clock bias and orbit position bias. These errors have the same effect on the reference station and the vehicle end, and can be canceled by differential operation. At the same time, when the NTRIP server module performs differential solution of RTK technology, double difference model solution is also needed. The NTRIP server module first calculates the "single difference" (eliminates satellite clock error) for the observation values of the same satellite from the reference station and the vehicle end, and then calculates the "double difference" (eliminates receiver clock error) for the single difference values between different satellites. Finally, the observation equation containing only the position deviation of the vehicle end is obtained. By solving this equation, the accurate position offset of the vehicle end relative to the reference station, i.e. the differential correction information, can be obtained. Finally, generate RTCM differential data and output. The NTRIP server module encapsulates the differential correction information (including reference station coordinates, error correction parameters, satellite tracking status, etc.) obtained by solving, according to the RTCM protocol (international standard format for differential data, such as RTCM3.2 version), generates a structured RTCM differential data frame, and sends it to the server through the Socket data channel established earlier. The server module then sends it to the vehicle end module through the server dynamic MQTT client module, providing data support for the vehicle end GNSS hardware to correct positioning errors and achieve high-precision positioning.

[0058] The service end module has the following overall effects: efficient acquisition and dynamic management of RTK accounts, independent processing and real-time forwarding of multi-vehicle differential data, automatic reconnection and resource recycling in abnormal states, improved RTK account resource utilization and system stability, and is the core management and control and data hub for multi-vehicle high-precision positioning services.

[0059] The above is the working process of the entire device, and the contents not described in detail in the specification all belong to the prior art known to those skilled in the art.

[0060] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements for part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A vehicle positioning management system based on an RTCM forwarding server, comprising a vehicle-side module, a server-side module, and an external association module, characterized in that: The vehicle-mounted module includes a combined inertial navigation module, a vehicle-mounted dynamic MQTT client module, and a GNSS hardware driver module. The vehicle-mounted module is responsible for collecting and processing positioning data, transmitting it to the server, receiving differential data, and driving the hardware to calculate the positioning. The server module includes a static MQTT client module, a dynamic MQTT client module, a vehicle state machine management module, a vehicle status and account resource management module, and an exception handling module. When the server module is working, it uniformly manages vehicle connections and accounts, forwards data, monitors status, and handles exceptions to ensure location. The external association module includes an NTRIP server module. When in operation, the external association module receives GPGGA data from the server, performs differential calculation to generate RTCM data and transmits it back, supporting high-precision positioning.

2. The vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The combined inertial navigation module is responsible for collecting raw vehicle positioning data and stitching the raw data into GPGGA data in NMEA format, completing the preprocessing of basic positioning data and providing basic data support for the positioning calculation of the subsequent GNSS hardware driver module.

3. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The vehicle-side dynamic MQTT client module undertakes the data transmission function. On the one hand, it sends the GPGGA data processed by the integrated inertial navigation module to the server through the MQTT protocol to realize the basic data transmission between the vehicle-side module and the server module. On the other hand, it receives the RTCM data sent by the server module and transmits it to the integrated inertial navigation module.

4. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The GNSS hardware driver module receives RTCM data transmitted by the combined inertial navigation module, combines it with RTCM differential data to correct positioning errors, drives the GNSS hardware to perform calculations, and finally calculates the high-precision positioning information of the vehicle.

5. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The server-side static MQTT client module is specifically used to interact with external systems to obtain configuration information, request key information such as RTK account, password, and mount point from external systems, and report account abnormality to external systems and request a new account when the NTRIP server module connection is abnormal.

6. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The server-side dynamic MQTT client module enables data interaction with the vehicle-side module, receiving GPGGA data sent by the vehicle-side module and simultaneously sending the RTCM data obtained by the NTRIP server module to the vehicle-side module, triggering the differential data processing flow. It also needs to cooperate with the vehicle status and account resource management module to adjust the data transmission strategy according to the vehicle connection status. The server-side static MQTT client module and the server-side dynamic MQTT client module form a dynamic channel of the dual-channel MQTT communication architecture.

7. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The vehicle state machine management module maintains an independent NTRIP session for each vehicle connected to the system and creates a corresponding differential data processing thread to ensure that the positioning data processing of each vehicle is independent and efficient, avoiding data confusion or delay. At the same time, the NTRIP server module transmits the returned RTCM data to the server-side dynamic MQTT client module via the MQTT protocol.

8. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The vehicle status and account resource management module integrates vehicle status machine management and RTK account management functions, monitors vehicle connection status in real time, detects vehicle activity periodically, and releases idle RTK accounts; at the same time, it manages the acquisition, allocation, and recycling of RTK accounts.

9. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The exception handling module monitors the connection status of the NTRIP server module. When a connection error occurs, it triggers an account error feedback and new account request process to rebuild the NTRIP connection and ensure the continuous and stable operation of the system.

10. A vehicle positioning management system based on an RTCM forwarding server according to claim 1, characterized in that: The NTRIP server module in the external association module receives GPGGA data forwarded by the dynamic MQTT client module in the server module, and uses RTK technology to perform differential calculation on the data to generate RTCM differential data for correcting positioning errors. The RTCM data is then transmitted back to the vehicle state machine management module in the server module via the Socket channel.

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