Detection vehicle accurate positioning system and method based on multi-channel wireless transmission

Abstract

The invention relates to the technical field of railway traffic, in particular to a detection vehicle accurate positioning system and method based on multi-channel wireless transmission. Comprising a positioning sending unit; a positioning receiving unit; and the detection and analysis unit is used for carrying out matching calculation on the train running distance and the track circuit code sequence information which are acquired in real time, and the theoretical path length and the expected track circuit code sequence in the line ledger database, and automatically executing a route switching decision. According to the method, on the basis of the train real-time driving distance deviation, track circuit code sequence matching and route priority, automation of route switching is achieved, lag and misjudgment of manual presetting are avoided, and the problems that route switching depends on manual work, efficiency is low, and positioning deviation is likely to be caused are solved; according to the method, multi-dimensional route matching of the track circuit code sequence and the mileage parameters is combined, and the matching precision of the positioning data and the line ledger is improved.

Description

Technical Field

[0001] This invention relates to the field of railway transportation technology, and more specifically, to a precise positioning system and method for inspection vehicles based on multi-channel wireless transmission. Background Technology

[0002] As core equipment ensuring the safe operation of railway lines, the positioning accuracy of railway inspection vehicles is directly related to the accuracy of defect location identification, providing crucial data support for subsequent maintenance and repair work. Currently, railway inspection vehicle positioning generally relies on operational data output from the locomotive's TAX box and LKJ equipment, synchronizing positioning information to the onboard inspection system via a wireless transmission link to achieve correlation and matching between inspection data and mileage location. The stability of wireless transmission and the reliability of positioning logic are key technical guarantees for adapting to complex scenarios such as tunnels and multiple routes within stations, directly impacting the efficiency and quality of inspection work.

[0003] Existing vehicle positioning technologies still face numerous bottlenecks in practical applications, with core technical issues concentrated in three aspects: First, insufficient reliability of wireless transmission. Most technologies employ single-channel designs, making them prone to data loss or transmission interruptions in signal-shielded areas such as tunnels. Furthermore, the lack of effective data verification and redundancy mechanisms makes it difficult to guarantee the integrity of positioning data. Second, low automation in route matching, relying on manually preset route parameters, leads to sluggish responses to complex track conditions, resulting in time-consuming switching and potential positioning errors due to human misjudgment. Third, poor positioning accuracy and equipment compatibility. Matching positioning data with track records relies solely on a single mileage parameter, neglecting features such as track circuit code sequence. Additionally, the integration of the positioning acquisition module and the TAX box lacks reliable isolation design, posing a safety hazard of interfering with the operation of existing equipment. Therefore, we propose a precise positioning system and method for vehicle inspection based on multi-channel wireless transmission. Summary of the Invention

[0004] The purpose of this invention is to provide a precise positioning system and method for a detection vehicle based on multi-channel wireless transmission, so as to solve the problems mentioned in the background art.

[0005] To address the aforementioned technical problems, one objective of this invention is to provide a precise positioning system for a detection vehicle based on multi-channel wireless transmission, comprising: The positioning transmission unit is integrated into the locomotive TAX box in the form of a pluggable board. It is connected to the back panel of the TAX box through power isolation and communication isolation circuits and is used to collect positioning data output by LKJ and TAX. The positioning transmission unit has at least two LoRa wireless communication modules operating at different frequencies built in, which are used to transmit the positioning data in a concurrent redundancy mode. The positioning receiving unit is installed inside the detection vehicle. It is used to receive positioning data sent by the positioning sending unit, and to perform verification, deduplication and fusion processing on the same data packets from different channels, and then broadcast the processed data packets to the detection analysis unit. The detection and analysis unit receives and processes the positioning data broadcast by the positioning receiving unit. It internally stores a line ledger database containing the theoretical path lengths and expected track circuit code sequence sequences of multiple routes. The detection and analysis unit automatically performs route switching decisions by matching and calculating the real-time collected train travel distance and track circuit code sequence information with the theoretical path lengths and expected track circuit code sequence sequences in the line ledger database, and automatically generates an analysis report after the detection is completed.

[0006] As a further improvement to this technical solution, the positioning and transmitting unit includes an isolated power supply module, a communication isolation module, and a microcontroller module, wherein: The isolated power supply module draws power from the back panel of the TAX box and provides safe power to the various functional units inside the board through an isolated DC-DC conversion circuit with integrated overcurrent, overvoltage, and reverse connection protection. The communication isolation module uses high-speed optical coupling isolation technology to connect to the communication interface on the back panel of the TAX box, achieving electrical isolation of signals and avoiding signal interference during the acquisition of positioning data output from LKJ and TAX. The microcontroller module is responsible for parsing the collected positioning data, generating data frames with timestamps and unique serial numbers, and caching the data for later transmission.

[0007] As a further improvement to this technical solution, the microcontroller module is equipped with a watchdog circuit, which is used to trigger the positioning and sending unit to automatically reset when the program runs abnormally, communication times out, or data cache is abnormal.

[0008] As a further improvement to this technical solution, the LoRa wireless communication module is electrically connected to the microcontroller module and is used to send positioning data processed by the microcontroller module; the LoRa wireless communication module operates at two different frequency points and the data transmission adopts the CRC16 cyclic redundancy check mechanism, adding a check bit to each frame of positioning data and synchronously outputting the same positioning data frame in a concurrent redundancy mode.

[0009] As a further improvement to this technical solution, the positioning receiving unit performs verification and deduplication processing on the same data packets from different channels, including the following steps: S2.1 Classify the data packets carrying positioning data received by each channel according to the order of reception time, extract the positioning data timestamp and unique sequence number recorded in each data packet, and establish a data packet-positioning data association identifier list; S2.2. The CRC16 cyclic redundancy check mechanism is adopted to check the integrity of the positioning data carried in each data packet and discard data packets that fail the check or have damaged positioning data. S2.3. Based on the associated identifier list, compare the timestamps and sequence numbers of the location data corresponding to data packets from different channels to identify duplicate data packets carrying the same location data. S2.4. Retain the data packet with the earliest reception time and whose location data verification has passed among the duplicate data packets, and delete the remaining duplicate data packets to form a set of data packets containing only one valid location data.

[0010] As a further improvement to this technical solution, the positioning receiving unit performs fusion processing on the same data packets from different channels, including the following steps: S2.5. From the set of data packets after verification and deduplication, extract all valid data packets carrying the same batch of positioning data, parse the field composition of the positioning data in each data packet, and count the completeness of each field. S2.6 Select the data package with the highest field completeness as the baseline data package, confirm the content in the other data packages in the same batch that is consistent with the baseline data package, and mark the missing or abnormal fields in the other data packages; S2.7 Based on the complete fields of the baseline data packet, the missing fields of the other data packets in the same batch are filled in, and the abnormal fields are corrected according to the corresponding fields of the baseline data packet to form preliminary fused positioning data; S2.8. Cross-validate the initially fused positioning data to confirm the consistency of key fields, generate standardized final fused positioning data, and encapsulate it into a unified data packet for broadcast to the detection and analysis unit.

[0011] As a further improvement to this technical solution, the detection and analysis unit includes a data receiving and processing module, a route ledger management module, a route matching decision module, and a detection report generation module, wherein: The data receiving and processing module is used to receive the fused positioning data broadcast by the positioning receiving unit and analyze and extract the real-time travel distance of the train. Real-time track circuit code sequence and data collection timestamp ; The route ledger management module is used to store and update the route ledger database, which contains unique identifiers and theoretical path lengths for each route. Expected track circuit code sequence and route priority parameters; The route matching decision module is used to call the route ledger management module. and ,Will and With the output of the data receiving and processing module and Perform matching calculations and output the route switching decision results; The detection report generation module is based on the matching calculation results of the intersection matching decision module and , The system ensures the integrity of the received data and automatically generates standardized test reports.

[0012] As a further improvement to this technical solution, the matching calculation algorithm of the route matching decision module includes the following steps: S3.1, the data receiving and processing module will , The data is transmitted to the route matching decision module, which, based on the current train location, filters out a set of related candidate routes from the route ledger database. And retrieve the corresponding path for each candidate path and ; S3.2, For each candidate path ,calculate With this route deviation value Set deviation threshold Remove Among the candidate routes, retain the subset of routes that meet the deviation requirements. ; S3.3, For the subset of paths Each path in Comparison With this route To determine the consistency, calculate the matching degree between the real-time code sequence and the expected code sequence. ; S3.4, If the path subset If only one route exists, it is directly designated as the current operating route; if multiple routes exist, the route with priority is selected. The highest path; if it exists For multiple identical routes, the route priority parameter in the route ledger database is called to select the route with the highest priority and trigger the route switching command; S3.5, The finalized route information and corresponding... and The data is associated and stored in the local cache to form a matching result dataset, providing data support for the detection report generation module.

[0013] As a further improvement to this technical solution, the test report generated by the test report generation module specifically includes: Based on the real-time train travel distance recorded by the data receiving and processing module Theoretical path length corresponding to the route in the route ledger Statistical analysis of the average positioning deviation throughout the entire process The maximum deviation value, minimum deviation value, and deviation distribution range are also marked throughout the process. The total number of route switching, successful switching, and false positives in the route matching decision module were statistically analyzed, with false positives being those resulting from subsequent routes being passed. With real-time track circuit code sequence Verify and confirm situations where the current route does not match the actual route, and calculate the route handover success rate. Includes data collection timestamps for each switch. The matching degree between the corresponding real-time code sequence and the expected code sequence and and deviation value ; The location data reception integrity rate is calculated based on the reception records of the data receiving and processing module. Simultaneously, the runtime and number of abnormal restarts of the statistical data receiving and processing module, the route ledger management module, and the route matching decision module are recorded to generate data integrity and system stability assessment conclusions.

[0014] The second objective of this invention is to provide a method for precise positioning of a testing vehicle based on multi-channel wireless transmission. The method, based on the aforementioned precise positioning system for a testing vehicle using multi-channel wireless transmission, includes the following steps: S1. Collect positioning data output from LKJ and TAX, and send the collected positioning data to the receiver in the detection vehicle in a concurrent redundancy mode through at least two built-in LoRa wireless communication modules operating at different frequencies. S2. Receive the location data sent by the sending end, and perform verification, deduplication and fusion processing on the same data packets from different channels in sequence; first, use the CRC16 cyclic redundancy check mechanism to remove the data packets with broken data, then identify and delete duplicate data packets based on the location data timestamp and unique sequence number, and finally use the data packet with the highest field completeness as the benchmark to fill in the missing fields and correct abnormal fields to form the final fused location data and broadcast it. S3. Receive the final fused positioning data, extract the real-time train travel distance, real-time track circuit code sequence, and data acquisition timestamp; call the theoretical path length, expected track circuit code sequence, and route priority parameters of each route in the pre-stored route ledger database, calculate the deviation between the real-time travel distance and the theoretical path length, and the matching degree between the real-time track circuit code sequence and the expected track circuit code sequence; after removing routes with deviation values ​​exceeding the set deviation threshold, automatically execute route switching decisions according to the matching degree and route priority. S4. Based on the deviation statistics between real-time driving distance and theoretical path length, route switching results, positioning data reception integrity rate, and the operating status of each part of the system, a standardized test report is automatically generated.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention improves the stability and integrity of positioning data transmission in signal-shielded areas such as tunnels by using multi-channel LoRa wireless communication modules for concurrent transmission, CRC16 cyclic redundancy check, and data deduplication and fusion processing. It solves the problems of easy packet loss and interruption and difficulty in ensuring data integrity in the single-channel transmission of existing technologies. 2. This invention uses a route decision algorithm based on real-time train travel distance deviation, track circuit code sequence matching, and route priority to automate route switching, avoiding the lag and misjudgment caused by manual pre-setting, and solving the problems of route switching relying on manual labor, low efficiency, and easy to cause positioning deviation. 3. This invention combines multi-dimensional route matching of track circuit code sequence and mileage parameters to improve the matching accuracy of positioning data and line ledger; at the same time, through the power and communication isolation design of the positioning acquisition module and TAX box, it eliminates the hidden danger of equipment integration interfering with the operation of the original equipment, and solves the problems of insufficient positioning accuracy and poor equipment compatibility. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the system framework of the present invention; Figure 2 This is a schematic diagram of the method steps of the present invention; The meanings of the labels in the diagram are as follows: 1. Positioning and transmitting unit; 11. Isolation power supply module; 12. Communication isolation module; 13. Microcontroller module; 14. LoRa wireless communication module; 2. Positioning and receiving unit; 3. Detection and analysis unit; 31. Data receiving and processing module; 32. Route ledger management module; 33. Route matching decision module; 34. Detection report generation module. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1As shown, this embodiment provides a precise positioning system for a detection vehicle based on multi-channel wireless transmission, including: The positioning transmission unit 1 is integrated into the locomotive TAX box in the form of a pluggable board. It is connected to the back panel of the TAX box through power isolation and communication isolation circuits and is used to collect positioning data output by LKJ and TAX. The positioning transmission unit 1 has at least two LoRa wireless communication modules 14 operating at different frequencies built in, which are used to transmit positioning data in a concurrent redundancy mode. The positioning and transmitting unit 1 adopts a pluggable board form, which is fully compatible with the mechanical installation specifications of the TAX boxes of TAX2 and TAX3 locomotives. It is connected to the back panel of the TAX box through a gold-plated connector and has the capability of hot-swapping. Internally, it integrates an isolated power supply module 11, a communication isolation module 12, a microcontroller module 13, and two LoRa wireless communication modules 14. Its core function is to safely collect positioning data output from LKJ and TAX, process it, and then transmit it in a concurrent redundant mode through dual LoRa channels.

[0019] In this step, the positioning and transmitting unit 1 includes an isolated power supply module 11, a communication isolation module 12, and a microcontroller module 13, wherein: The isolated power module 11 draws power from the back panel of the TAX box and provides safe power to the various functional units inside the board through an isolated DC-DC conversion circuit with integrated overcurrent, overvoltage and reverse connection protection. Specifically, the isolated power supply module 11 draws power from the 110V DC power interface on the back panel of the TAX box. It uses a series self-resetting fuse for overcurrent protection, a parallel TVS diode for overvoltage protection, and a series Schottky diode for reverse connection protection. The input voltage is converted into a stable 5V DC voltage through an isolated DC-DC converter. The input voltage range of the isolated DC-DC converter covers DC 40~160V, and the primary and secondary isolation voltage is ≥2kV. The output 5V voltage is further regulated to 3.3V by a voltage regulator chip, which powers the microcontroller module 13, the communication isolation module 12, and the LoRa wireless communication module 14. Each power supply branch is connected in series with a 0Ω fuse for easy fault location, ensuring the safety of the board power supply and preventing fault feedback to the TAX box back panel power supply.

[0020] The communication isolation module 12 uses high-speed optical coupling isolation technology to connect to the communication interface on the back panel of the TAX box. During the acquisition of positioning data output from LKJ and TAX, electrical isolation of signals is achieved to avoid signal interference. Specifically, the communication isolation module 12 uses an RS485 interface to connect to the corresponding interface on the back panel of the TAX box. Only the receive pins (A, B) and signal ground are used, and the transmit pins (Y, Z) are physically disconnected to avoid sending data to the RS485 bus. Electrical isolation of the signal is achieved through a high-speed optocoupler-isolated RS485 transceiver with an isolation voltage ≥2.5kV. The transmission rate meets the real-time acquisition requirements of LKJ / TAX positioning data. An RC filter circuit is connected in parallel at the interface to suppress electromagnetic interference. The signal line uses shielded twisted-pair wiring and the shielding layer is grounded to reduce crosstalk, ensuring that the original signal of the TAX box is not interfered with during data acquisition.

[0021] The microcontroller module 13 is responsible for parsing the collected positioning data, generating data frames with timestamps and unique sequence numbers, and buffering the data for later transmission. The microcontroller module 13 is equipped with a watchdog circuit, which triggers the positioning transmission unit 1 to automatically reset in the event of program malfunction, communication timeout, or data buffering error.

[0022] Specifically, the microcontroller module 13 adopts a low-power ARM Cortex-M core microcontroller with built-in Flash and RAM of sufficient capacity to meet data processing and caching requirements. Its minimum system includes a main crystal oscillator (providing clock signals), a real-time clock crystal oscillator (for generating timestamps), a reset circuit (ensuring stable reset during power fluctuations), and a Boot configuration interface (facilitating firmware upgrades). It receives LKJ / TAX positioning data transmitted by the communication isolation module 12 through the UART interface, encapsulates the data into data frames containing packet_id, timestamp, sequence_num, data_payload, CRC16 checksum, and channel_id, and temporarily stores them in a designated area of ​​Flash (the cache depth supports storing 1000 frames of data). It enables a built-in independent watchdog timer, which is fed periodically during normal program operation. If the program crashes, communication times out, or the cache overflows, the watchdog timer triggers the positioning transmission unit 1 to automatically reset, restoring the system to normal operation.

[0023] In this step, the LoRa wireless communication module 14 is electrically connected to the microcontroller module 13 and is used to send the positioning data processed by the microcontroller module 13. The LoRa wireless communication module 14 operates at two different frequency points and uses the CRC16 cyclic redundancy check mechanism for data transmission. It adds a check bit to each frame of positioning data and outputs the same positioning data frame synchronously in a concurrent redundancy mode.

[0024] Specifically, the positioning and transmitting unit 1 has two built-in LoRa wireless communication modules 14, both operating in the 470MHz frequency band. The frequency spacing between the two modules meets the anti-interference requirements (e.g., ≥10MHz or engineering compliance spacing). It is electrically connected to the microcontroller module 13 through an independent UART interface and receives the data frames encapsulated by the microcontroller module 13. It adopts a concurrent redundant transmission mode, with the two modules synchronously receiving and transmitting the same data frames, and the transmission rate is controlled at 8-10 frames per second. The data transmission adopts a CRC16 cyclic redundancy check mechanism, and the check range covers the core fields of the data frame to ensure data integrity. The transmission distance is ≥500 meters (open environment), which meets the wireless communication requirements of the inspection vehicle and the locomotive.

[0025] The positioning receiving unit 2 is installed inside the detection vehicle. It is used to receive the positioning data sent by the positioning sending unit 1, and to perform verification, deduplication and fusion processing on the same data packets from different channels. Then, it broadcasts the processed data packets to the detection analysis unit 3. The positioning receiver unit 2 adopts a wall-mounted chassis design and is installed on the inner wall of the inspection vehicle (preferably in an area with minimal signal obstruction and vibration). The chassis is adapted to the internal installation space of the inspection vehicle and has a built-in AC-DC power adapter (input is the inspection vehicle's AC220V power supply, output is a stable DC12V voltage) to provide safe power to the internal circuitry of the positioning receiver unit 2. Internally, it includes data receiving circuitry, data processing circuitry, and data broadcasting circuitry, all connected via onboard wiring.

[0026] In this step, the positioning receiving unit 2 performs verification and deduplication processing on the same data packets from different channels, including the following steps: S2.1 Classify the data packets carrying positioning data received by each channel according to the order of reception time, extract the positioning data timestamp and unique sequence number recorded in each data packet, and establish a data packet-positioning data association identifier list; Specifically, the data receiving circuit synchronously receives data packets from the dual LoRa channels of the positioning transmitting unit 1, records the local reception time of each data packet, and classifies them in ascending order of reception time; the data processing circuit extracts the "positioning data timestamp" and "unique sequence number" from the data packets and establishes an associated identifier list of "data packet-timestamp-sequence number-reception time" in internal storage.

[0027] S2.2. The CRC16 cyclic redundancy check mechanism is adopted to check the integrity of the positioning data carried in each data packet and discard data packets that fail the check or have damaged positioning data. Specifically, the data processing circuit calls the CRC16 cyclic redundancy check algorithm to calculate the check value of the "location data payload part" of the data packet and compare it with the check bit of the data packet itself; if the check fails, the data packet is deleted, and if the check passes, it is temporarily stored in the "deduplication area" of the internal storage.

[0028] S2.3. Based on the associated identifier list, compare the timestamps and sequence numbers of the location data corresponding to data packets from different channels to identify duplicate data packets carrying the same location data. Specifically, the data processing circuit uses "timestamp + sequence number" as the unique identifier for the same batch of data, compares data packets from different channels within the "deduplication zone", and marks duplicate data packets with the same timestamp and sequence number.

[0029] S2.4. Retain the data packet with the earliest reception time and whose location data verification has passed among the duplicate data packets, and delete the remaining duplicate data packets to form a set of data packets containing only one valid location data.

[0030] In this step, the fusion processing of identical data packets from different channels by the positioning receiving unit 2 includes the following steps: S2.5. From the set of data packets after verification and deduplication, extract all valid data packets carrying the same batch of positioning data, parse the field composition of the positioning data in each data packet, and count the completeness of each field. Specifically, valid data packets of the same batch of positioning data are extracted from the "area to be merged", the positioning data fields of each data packet are parsed, and the completeness of each field is counted by "field existence + format compliance detection". The results are temporarily stored in the "log area" of internal storage.

[0031] S2.6 Select the data package with the highest field completeness as the baseline data package, confirm the content in the other data packages in the same batch that is consistent with the baseline data package, and mark the missing or abnormal fields in the other data packages; Specifically, the baseline data package is selected based on "highest field completeness". The remaining data packages are compared with the baseline data package field by field. Fields that match are marked as "confirmed" and missing / abnormal fields are marked as "to be completed / to be corrected". The marking results are updated to the "log area".

[0032] S2.7 Based on the complete fields of the baseline data packet, the missing fields of the other data packets in the same batch are filled in, and the abnormal fields are corrected according to the corresponding fields of the baseline data packet to form preliminary fused positioning data; S2.8. Cross-validate the initially fused positioning data to confirm the consistency of key fields, generate standardized final fused positioning data, and encapsulate it into a unified data packet for broadcast to the detection and analysis unit 3.

[0033] Furthermore, the data processing circuit of the positioning receiving unit 2 transmits the "standardized data packet" to the data broadcasting circuit; the data broadcasting circuit adopts an industrial-grade RS485 interface and establishes communication with the RS485 interface of the detection and analysis unit 3 to send data in a "timed multicast" (the broadcasting cycle is synchronized with the positioning sending unit 1); it has a built-in "send confirmation mechanism": after sending, it waits for the confirmation code to be received. If the timeout occurs, it retransmits (retransmit ≤ 2 times). If there is still no feedback after 2 retransmissions, the fault information is transmitted to the data processing circuit and recorded in the "log area".

[0034] The detection and analysis unit 3 is used to receive and process the positioning data broadcast by the positioning receiving unit 2. It has an internally stored line ledger database containing the theoretical path lengths and expected track circuit code sequence sequences of multiple routes. The detection and analysis unit 3 automatically performs route switching decisions by matching and calculating the real-time collected train travel distance and track circuit code sequence information with the theoretical path lengths and expected track circuit code sequence sequences in the line ledger database, and automatically generates an analysis report after the detection is completed.

[0035] Specifically, the detection and analysis unit 3 adopts a rack-mount server design, installed in a standard cabinet in the control room of the detection vehicle, powered by an AC220V vehicle power supply, with built-in redundant power modules to ensure continuous operation. The data receiving and processing module 31, the route ledger management module 32, the route matching decision module 33, and the detection report generation module 34 exchange data via an industrial Ethernet switch. Its core functions are: receiving fused positioning data broadcast by the positioning receiving unit 2; completing data parsing, ledger retrieval, and route matching decisions through the collaboration of various modules; automatically executing route switching; and generating standardized detection reports.

[0036] In this step, the detection and analysis unit 3 includes a data receiving and processing module 31, a route ledger management module 32, a route matching decision module 33, and a detection report generation module 34, wherein: Data receiving and processing module 31 is used to receive the fused positioning data broadcast by positioning receiving unit 2, and parse and extract the real-time travel distance of the train. Real-time track circuit code sequence and data collection timestamp ; Specifically, the data receiving and processing module 31 uses an Advantech PCI-1680U industrial-grade RS485 serial communication card (4 independent interfaces, baud rate adjustable from 1200bps to 115200bps), and is connected to the broadcast circuit of the positioning receiving unit 2 via shielded twisted-pair cable (0.5mm² wire diameter, shielding grounding conforms to anti-interference design specifications), adapting to the strong electromagnetic environment of the detection vehicle; the driver is based on the real-time Linux system RT-UART protocol, and the interrupt response time is adapted to the data receiving requirements in high-speed mobile scenarios, avoiding data packet loss during high-speed movement; after receiving the "standardized data packet", the data receiving and processing module 31 first suppresses mileage jumps through sliding window filtering, as shown in the following formula: ; in The original real-time train travel distance is obtained by analyzing the data from the positioning receiver unit 2. Indicates to Stable mileage data obtained after applying sliding window filtering. The length of the sliding window (when the speed is ≤80km / h) >80km / h ), For the first Raw mileage data at any given time; The data time series is then verified using a dual anchoring method of timestamp and mileage, as shown in the following formula: ; ; in This is the difference in timestamps between frames. The maximum transmission period for the positioning transmission unit 1 is 0.125s, consistent with the design of the transmitting end. This represents the inter-frame mileage difference. The maximum speed of the inspection vehicle is approximately 33.33 m / s, which complies with the railway inspection vehicle operating speed specifications. Final parsing , (Code sequence string) according to" The data is stored in a local SQLite database in a specific format and simultaneously pushed to the route matching decision module 33 via UDP protocol. The transmission delay meets the requirements for real-time interaction of positioning data.

[0037] The route ledger management module 32 is used to store and update the route ledger database, which contains the unique identifier and theoretical path length of each route. Expected track circuit code sequence and route priority parameters; Specifically, the route ledger management module 32 uses a Samsung 870 EVO 2TB industrial-grade SSD (MTBF ≥ 2 million hours, meeting the reliability requirements of industrial equipment storage) as the storage medium, and has a built-in MySQL 8.0 database (InnoDB transaction engine to ensure data consistency). It constructs a three-dimensional ledger model of "route-code sequence-priority", and the core table structure includes a route information table and a code sequence table. To adapt to the dynamic adjustment of priority in transportation scenarios, the following formula is used to calculate the dynamic priority: ; in It is a dynamic priority (integer from 1 to 10). The scenario coefficient is 0.4 for peak hours, 0.1 for off-peak hours, and 0 for trough hours, based on the railway transportation peak period classification standard. For peak period indicators (1=peak / 0=other), such as the Handan-Jinan Railway during peak hours, the main line basic priority is 5→dynamic priority is 7, and the siding is 3→4; Meanwhile, the route ledger management module 32 supports importing "Route Ledger Update Package.xlsx" via USB 3.0 (automatic verification during import). and (Length ≥ 3, ensuring the validity of ledger data) and remote updates via the railway intranet (SSL / TLS 1.3 encryption, ensuring data transmission security). After the update, the old ledger is automatically backed up to ensure that the ledger is consistent with the actual line and can be rolled back.

[0038] The route matching decision module 33 is used to call the route ledger management module 32. and ,Will and The output of the data receiving and processing module 31 and Perform matching calculations and output the route switching decision results; The detection report generation module 34 is based on the matching calculation results of the intersection matching decision module 33 and , The system ensures the integrity of the received data and automatically generates standardized test reports.

[0039] In this step, the matching calculation algorithm of the route matching decision module 33 includes the following steps: S3.1, Data receiving and processing module 31 will , The data is transmitted to the route matching decision module 33, which, based on the current train location, filters out a set of related candidate routes from the route ledger database. And retrieve the corresponding path for each candidate path and The mileage segment mapping formula is as follows: ; ; in express The corresponding line section is determined by the start and end mileage of the section pre-stored in the line ledger. , Sure; Denotes the set of candidate paths. For the first 10 candidate routes, each Theoretical path length in the associated route ledger Expected track circuit code sequence .

[0040] S3.2, For each candidate path ,calculate With this route deviation value Set deviation threshold Remove Among the candidate routes, retain the subset of routes that meet the deviation requirements. ; Specifically, for each candidate path Calculate real-time driving distance With theoretical path length deviation value And set a deviation threshold. (Based on the scenario setting, such as within the station) interval ), filter out those that meet the requirements Approach subset The deviation calculation formula is as follows: .

[0041] S3.3, For the subset of paths Each path in Comparison With this route To determine the consistency, calculate the matching degree between the real-time code sequence and the expected code sequence. ; Specifically, for the subset of approaches Each path Compare the real-time track circuit code sequence With the expected track circuit code sequence Matching degree The formula is as follows: ; in, and The number of code sequence fields with consistent characters; (or The total number of code sequence fields (both of which have the same length).

[0042] S3.4, If the path subset If only one route exists, it is directly designated as the current operating route; if multiple routes exist, the route with priority is selected. The highest path; if it exists For multiple identical routes, the route priority parameter in the route ledger database is called to select the route with the highest priority and trigger the route switching command; S3.5, The finalized route information and corresponding... and The data is associated and stored in the local cache to form a matching result dataset, which provides data support for the detection report generation module 34.

[0043] In this step, the test report generation module 34 is implemented based on an embedded software platform, automatically capturing data from various modules to generate a standardized test report. The test report generated by the test report generation module 34 specifically includes: Based on the real-time train travel distance recorded by data receiving and processing module 31 Theoretical path length corresponding to the route in the route ledger Statistical analysis of the average positioning deviation throughout the entire process The maximum deviation value, minimum deviation value, and deviation distribution range are also marked throughout the process. Specifically, based on the matching result dataset of the route matching decision module 33, the average positioning deviation throughout the entire route is statistically analyzed. Maximum deviation value Minimum deviation value The formula for calculating the mean deviation is as follows: ; in, This represents the total number of valid deviation data.

[0044] The total number of route switching, successful switching, and false positives in the route matching decision module 33 are statistically analyzed, including the number of false positives that resulted in subsequent routes being switched. With real-time track circuit code sequence Verify and confirm situations where the current route does not match the actual route, and calculate the route handover success rate. Includes data collection timestamps for each switch. The matching degree between the corresponding real-time code sequence and the expected code sequence and and deviation value ; Specifically, calculate the route handover success rate. The formula is as follows: ; in, Indicates the number of successful switches; This indicates the total number of route changes.

[0045] The location data reception integrity rate is calculated based on the reception records of the data receiving and processing module 31. Simultaneously, the runtime and number of abnormal restarts of the statistical data receiving and processing module 31, the route ledger management module 32, and the route matching decision module 33 are recorded to generate data integrity and system stability assessment conclusions.

[0046] Specifically, calculate the location data reception integrity rate. The formula is as follows: ; in, This indicates the number of successfully received data packets; This indicates the total number of frames sent by the positioning and sending unit 1.

[0047] like Figure 2 As shown, this embodiment also provides a method for precise positioning of a testing vehicle based on multi-channel wireless transmission. Based on the aforementioned precise positioning system for a testing vehicle based on multi-channel wireless transmission, the method includes the following steps: S1. Collect positioning data output from LKJ and TAX, and send the collected positioning data to the receiver in the detection vehicle in a concurrent redundancy mode through at least two built-in LoRa wireless communication modules 14 operating at different frequencies. S2. Receive the location data sent by the sending end, and perform verification, deduplication and fusion processing on the same data packets from different channels in sequence; first, use the CRC16 cyclic redundancy check mechanism to remove the data packets with broken data, then identify and delete duplicate data packets based on the location data timestamp and unique sequence number, and finally use the data packet with the highest field completeness as the benchmark to fill in the missing fields and correct abnormal fields to form the final fused location data and broadcast it. S3. Receive the final fused positioning data, extract the real-time train travel distance, real-time track circuit code sequence, and data acquisition timestamp; call the theoretical path length, expected track circuit code sequence, and route priority parameters of each route in the pre-stored route ledger database, calculate the deviation between the real-time travel distance and the theoretical path length, and the matching degree between the real-time track circuit code sequence and the expected track circuit code sequence; after removing routes with deviation values ​​exceeding the set deviation threshold, automatically execute route switching decisions according to the matching degree and route priority. S4. Based on the deviation statistics between real-time driving distance and theoretical path length, route switching results, positioning data reception integrity rate, and the operating status of each part of the system, a standardized test report is automatically generated.

[0048] Those skilled in the art will understand that the process of implementing all or part of the steps of the above embodiments can be carried out by hardware or by a program instructing the relevant hardware.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A precise positioning system for a testing vehicle based on multi-channel wireless transmission, characterized in that, include: The positioning transmission unit (1) is integrated into the locomotive TAX box in the form of a pluggable board and is connected to the back panel of the TAX box through power isolation and communication isolation circuits. It is used to collect positioning data output by LKJ and TAX. The positioning transmission unit (1) has at least two LoRa wireless communication modules (14) working at different frequencies built in, which are used to transmit positioning data in a concurrent redundancy mode. The positioning receiving unit (2) is installed in the detection vehicle and is used to receive the positioning data sent by the positioning sending unit (1), and to perform verification, deduplication and fusion processing on the same data packets from different channels, and then broadcast the processed data packets to the detection analysis unit (3). The detection and analysis unit (3) is used to receive and process the positioning data broadcast by the positioning receiving unit (2). It has a pre-stored line ledger database containing the theoretical path lengths and expected track circuit code sequence sequences of multiple routes. The detection and analysis unit (3) automatically performs route switching decisions by matching and calculating the real-time collected train travel distance and track circuit code sequence information with the theoretical path length and expected track circuit code sequence sequences in the line ledger database, and automatically generates an analysis report after the detection is completed.

2. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 1, characterized in that, The positioning and transmitting unit (1) includes an isolated power supply module (11), a communication isolation module (12), and a microcontroller module (13), wherein: The isolated power module (11) draws power from the back panel of the TAX box and provides safe power supply to the various functional units inside the board through an isolated DC-DC conversion circuit with integrated overcurrent, overvoltage and reverse connection protection. The communication isolation module (12) is connected to the TAX box backplane communication interface using high-speed optical coupler isolation technology. During the acquisition of positioning data output by LKJ and TAX, electrical isolation of signals is achieved to avoid signal interference. The microcontroller module (13) is responsible for parsing the collected positioning data, generating data frames with timestamps and unique serial numbers, and caching the data for later processing.

3. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 2, characterized in that, The microcontroller module (13) is equipped with a watchdog circuit, which is used to trigger the positioning and sending unit (1) to automatically reset when the program runs abnormally, communication times out or data cache is abnormal.

4. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 3, characterized in that, The LoRa wireless communication module (14) is electrically connected to the microcontroller module (13) and is used to send the positioning data processed by the microcontroller module (13). The LoRa wireless communication module (14) operates at two different frequency points and uses the CRC16 cyclic redundancy check mechanism to send data. It adds a check bit to each frame of positioning data and outputs the same positioning data frame synchronously in a concurrent redundancy mode.

5. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 4, characterized in that, The positioning receiving unit (2) performs verification and deduplication processing on the same data packets from different channels, including the following steps: S2.1 Classify the data packets carrying positioning data received by each channel according to the order of reception time, extract the positioning data timestamp and unique sequence number recorded in each data packet, and establish a data packet-positioning data association identifier list; S2.

2. The CRC16 cyclic redundancy check mechanism is adopted to check the integrity of the positioning data carried in each data packet and discard data packets that fail the check or have damaged positioning data. S2.

3. Based on the associated identifier list, compare the timestamps and sequence numbers of the location data corresponding to data packets from different channels to identify duplicate data packets carrying the same location data. S2.

4. Retain the data packet with the earliest reception time and whose location data verification has passed among the duplicate data packets, and delete the remaining duplicate data packets to form a set of data packets containing only one valid location data.

6. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 5, characterized in that, The positioning receiving unit (2) performs fusion processing on the same data packets from different channels, including the following steps: S2.

5. From the set of data packets after verification and deduplication, extract all valid data packets carrying the same batch of positioning data, parse the field composition of the positioning data in each data packet, and count the completeness of each field. S2.6 Select the data package with the highest field completeness as the baseline data package, confirm the content in the other data packages in the same batch that is consistent with the baseline data package, and mark the missing or abnormal fields in the other data packages; S2.7 Based on the complete fields of the baseline data packet, the missing fields of the other data packets in the same batch are filled in, and the abnormal fields are corrected according to the corresponding fields of the baseline data packet to form preliminary fused positioning data; S2.

8. Cross-validate the initially fused positioning data to confirm the consistency of key fields, generate the final fused positioning data with standardized format, and encapsulate it into a unified data packet for broadcast to the detection and analysis unit (3).

7. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 6, characterized in that, The detection and analysis unit (3) includes a data receiving and processing module (31), a route ledger management module (32), a route matching decision module (33), and a detection report generation module (34), wherein: The data receiving and processing module (31) is used to receive the fused positioning data broadcast by the positioning receiving unit (2) and parse and extract the real-time travel distance of the train. Real-time track circuit code sequence and data collection timestamp ; The route ledger management module (32) is used to store and update the route ledger database, which includes the unique identifier of each route and the theoretical path length. Expected track circuit code sequence and route priority parameters; The route matching decision module (33) is used to call the route ledger management module (32) in and ,Will and The output of the data receiving and processing module (31) and Perform matching calculations and output the route switching decision results; The detection report generation module (34) is based on the matching calculation results of the intersection matching decision module (33) and , The system ensures the integrity of the received data and automatically generates standardized test reports.

8. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 7, characterized in that, The matching calculation algorithm of the route matching decision module (33) includes the following steps: S3.1, Data receiving and processing module (31) will , The data is transmitted to the route matching decision module (33), which, in conjunction with the current train position, filters out a set of related candidate routes from the route ledger database. And retrieve the corresponding path for each candidate path and ; S3.2, For each candidate path ,calculate With this route deviation value Set deviation threshold Remove Among the candidate routes, retain the subset of routes that meet the deviation requirements. ; S3.3, For the subset of paths Each path in Comparison With this route To determine the consistency, calculate the matching degree between the real-time code sequence and the expected code sequence. ; S3.4, If the path subset If only one route exists, it is directly designated as the current operating route; if multiple routes exist, the route with priority is selected. The highest path; if it exists For multiple identical routes, the route priority parameter in the route ledger database is called to select the route with the highest priority and trigger the route switching command; S3.5, The finalized route information and corresponding... and The associated data is stored in the local cache to form a matching result dataset, which provides data support for the detection report generation module (34).

9. The precise positioning system for a detection vehicle based on multi-channel wireless transmission according to claim 8, characterized in that, The test report generated by the test report generation module (34) specifically includes: Based on the real-time train travel distance recorded by the data receiving and processing module (31) Theoretical path length corresponding to the route in the route ledger Statistical analysis of the average positioning deviation throughout the entire process The maximum deviation value, minimum deviation value, and deviation distribution range are also marked throughout the process. The total number of route switching, the number of successful switching, and the number of misjudgments were recorded in the route matching decision module (33), where misjudgments were subsequent routes that passed through. With real-time track circuit code sequence Verify and confirm situations where the current route does not match the actual route, and calculate the route handover success rate. Includes data collection timestamps for each switch. The matching degree between the corresponding real-time code sequence and the expected code sequence and and deviation value ; The location data reception integrity rate is calculated based on the reception records of the data receiving and processing module (31). Meanwhile, the runtime and number of abnormal restarts of the statistical data receiving and processing module (31), the route ledger management module (32), and the route matching decision module (33) are recorded to generate data integrity and system stability assessment conclusions.

10. A method for precise positioning of a detection vehicle based on multi-channel wireless transmission, based on the precise positioning system for a detection vehicle based on multi-channel wireless transmission as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Collect the positioning data output by LKJ and TAX, and send the collected positioning data to the receiver in the detection vehicle in a concurrent redundancy mode through at least two LoRa wireless communication modules (14) that operate at different frequencies. S2. Receive the location data sent by the sending end, and perform verification, deduplication and fusion processing on the same data packets from different channels in sequence. First, use the CRC16 cyclic redundancy check mechanism to remove the data packets with data corruption, then identify and delete duplicate data packets based on the location data timestamp and unique sequence number, and finally use the data packet with the highest field completeness as the benchmark to fill in the missing fields and correct abnormal fields to form the final fused location data and broadcast it. S3. Receive the final fused positioning data, extract the real-time train travel distance, real-time track circuit code sequence, and data acquisition timestamp; call the theoretical path length, expected track circuit code sequence, and route priority parameters of each route in the pre-stored route ledger database, calculate the deviation between the real-time travel distance and the theoretical path length, and the matching degree between the real-time track circuit code sequence and the expected track circuit code sequence; after removing routes with deviation values ​​exceeding the set deviation threshold, automatically execute route switching decisions according to the matching degree and route priority. S4. Based on the deviation statistics between real-time driving distance and theoretical path length, route switching results, positioning data reception integrity rate, and the operating status of each part of the system, a standardized test report is automatically generated.

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