A multi-channel wireless transmission-based detection vehicle accurate positioning system and method

Abstract

The present application 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, which comprises a positioning sending unit, a positioning receiving unit and a detection analysis unit; the detection analysis unit matches and calculates the real-time collected train running distance and track circuit code sequence information with the theoretical path length and expected track circuit code sequence in the line account database to automatically execute route switching decision; the present application realizes the automation of route switching based on the route decision algorithm of train real-time running distance deviation, track circuit code sequence matching and route priority, avoids the lag and misjudgment of artificial presetting, solves the problems of route switching dependence on artificial operation, low efficiency and easy positioning deviation; the present application improves the matching precision of positioning data and line account by combining the multi-dimensional route matching of track circuit code sequence and mileage parameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of railway traffic, in particular to a detection vehicle accurate positioning system and method based on multi-channel wireless transmission. BACKGROUND

[0002] As the core equipment to ensure the safety of line operation, the positioning accuracy of the railway detection vehicle is directly related to the accuracy of disease location identification, and is an important data support for subsequent maintenance and repair work. At present, the positioning of the railway detection vehicle generally relies on the operation data output by the locomotive TAX box and LKJ equipment, and the positioning information is synchronized to the vehicle-mounted detection system through a wireless transmission link to realize the matching of detection data and mileage position. Among them, the stability of wireless transmission and the reliability of positioning logic are the key technical supports for adapting to complex scenes such as tunnels and multiple routes in stations, and directly affect the efficiency and quality of detection work.

[0003] The existing detection vehicle positioning technology still has many bottlenecks in actual application, and the core technical problems are concentrated in three aspects: first, the wireless transmission reliability is insufficient, and a single channel design is mostly used, which is easy to cause data packet loss or transmission interruption in signal shielding areas such as tunnels, and lacks effective data verification and redundancy mechanism, making it difficult to guarantee the integrity of positioning data; second, the route matching automation degree is low, which relies on manual preset route parameters, and the response is lagging when facing complex line conditions, which not only takes a long time to switch, but also is easy to cause positioning deviation due to manual misjudgment; third, the positioning accuracy and equipment compatibility are poor, and the matching of positioning data and line account only relies on a single mileage parameter without combining track circuit code sequence and other characteristic information, and the integration of the positioning collection module and the TAX box lacks reliable isolation design, which has the safety hazard of interfering with the operation of the original equipment. In view of this, we propose a detection vehicle accurate positioning system and method based on multi-channel wireless transmission. SUMMARY

[0004] The purpose of the present application is to provide a detection vehicle accurate positioning system and method based on multi-channel wireless transmission to solve the problems raised in the background art.

[0005] To solve the above technical problems, one of the purposes of the present application is to provide a detection vehicle accurate positioning system based on multi-channel wireless transmission, which comprises:

[0006] A positioning sending unit is integrated in the form of a pluggable board card in the locomotive TAX box, connected to the TAX box backplane through power isolation and communication isolation circuit, used for collecting positioning data output by LKJ and TAX; the positioning sending unit is built-in at least two LoRa wireless communication modules working at different frequencies, used for sending positioning data in concurrent redundancy mode;

[0007] A positioning receiving unit is arranged in the detection vehicle, used for receiving the positioning data sent by the positioning sending unit, checking, de-duplicating and fusing the same data packets from different channels, and broadcasting the processed data packets to the detection analysis unit;

[0008] A detection analysis unit is used for receiving and processing the positioning data broadcast by the positioning receiving unit, and pre-storing a line account database containing the theoretical path length of multiple routes and the expected track circuit code sequence in the internal database; the detection analysis unit automatically performs route switching decision by matching the real-time collected train running distance and track circuit code sequence with the theoretical path length and expected track circuit code sequence in the line account database, and automatically generates an analysis report after the detection is completed.

[0009] As a further improvement of the technical solution, the positioning sending unit comprises an isolation power module, a communication isolation module and a micro control module, wherein:

[0010] The isolation power module takes power from the TAX box backplane, and provides safe power supply for each functional unit in the board through the isolation type DC-DC conversion circuit integrated with overcurrent, overvoltage and reverse connection protection;

[0011] The communication isolation module is connected with the TAX box backplane communication interface through high-speed optocoupler isolation technology, realizes electrical isolation of signals during collection of positioning data output by LKJ and TAX, and avoids signal interference;

[0012] The micro control module is responsible for analyzing the collected positioning data, generating data frames with time stamp and unique sequence number, and buffering the data for sending.

[0013] As a further improvement of the technical solution, the micro control module is provided with a watchdog circuit, which is used to trigger automatic reset of the positioning sending unit when the program runs abnormally, communication times out or data buffering is abnormal.

[0014] As a further improvement of the technical solution, the LoRa wireless communication module is electrically connected with the micro control module, used for sending the positioning data processed by the micro control module; the LoRa wireless communication module works at two different frequencies and uses CRC16 cyclic redundancy check mechanism for data sending, adds check bits to each frame of positioning data and synchronously outputs the same positioning data frame in concurrent redundancy mode.

[0015] As a further improvement of the technical solution, the positioning receiving unit checks and de-duplicates the same data packets from different channels, including the following steps:

[0016] S2.1, classify the data packets carrying positioning data received by each channel in chronological order, extract the positioning data timestamp and unique sequence number recorded in each data packet, and establish a data packet-positioning data association identification list;

[0017] S2.2, use the CRC16 cyclic redundancy check mechanism to check the integrity of the positioning data carried in each data packet, and eliminate data packets with failed check and damaged positioning data;

[0018] S2.3, based on the association identification list, compare the positioning data timestamps and sequence numbers corresponding to data packets from different channels to identify duplicate data packets carrying the same positioning data;

[0019] S2.4, keep the data packet with the earliest receiving time and passed positioning data check among the duplicate data packets, and delete the remaining duplicate data packets, to form a data packet set containing only unique valid positioning data.

[0020] As a further improvement of the technical solution, the fusion processing of the same data packets from different channels by the positioning receiving unit includes the following steps:

[0021] S2.5, from the data packet set 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;

[0022] S2.6, select the data packet with the highest field completeness as the reference data packet, confirm the contents consistent with the reference data packet in the remaining data packets of the same batch, and mark the missing or abnormal fields in the remaining data packets;

[0023] S2.7, based on the complete fields of the reference data packet, complete the missing fields of the remaining data packets of the same batch, and correct the abnormal fields according to the corresponding fields of the reference data packet, to form the preliminary fused positioning data;

[0024] S2.8, cross-check the preliminary fused positioning data to confirm the consistency of the key fields, generate the final fused positioning data in a standardized format, and encapsulate it as a unified data packet to broadcast to the detection and analysis unit.

[0025] As a further improvement of the technical solution, the detection and analysis unit includes a data receiving and processing module, a line account management module, a route matching decision module, and a detection report generation module, wherein:

[0026] The data receiving and processing module is used to receive the fused positioning data broadcast by the positioning receiving unit, parse and extract the real-time running distance of the train , the real-time track circuit code sequence and the data acquisition timestamp ;

[0027] The line account management module is used for storing and updating a line account database, which contains the unique identification of each route, the theoretical path length , the expected track circuit code sequence and the route priority parameter;

[0028] The route matching decision module is used for calling and in the line account management module, and matching calculation with and output by the data receiving and processing module, and outputting the route switching decision result;

[0029] The detection report generation module automatically generates a standardized detection report based on the matching calculation result of the route matching decision module and , the receiving integrity.

[0030] As a further improvement of the technical solution, the matching calculation algorithm process of the route matching decision module includes the following steps:

[0031] S3.1, the data receiving and processing module transmits , to the route matching decision module, the route matching decision module combines the current train position, filters out the associated candidate route set from the line account database, and calls the corresponding and of each candidate route;

[0032] S3.2, for each candidate route , the deviation value of and the route is calculated, the deviation threshold is set, the candidate route is eliminated, and the route subset satisfying the deviation requirement is reserved;

[0033] S3.3, for each route in the route subset , the consistency of and the route is compared, and the matching degree of the real-time code sequence and the expected code sequence is calculated ;

[0034] S3.4, if the route subset If there is only one route, it is directly determined as the current running route; if there are multiple routes, the highest route is preferentially selected If there are multiple routes, the route priority parameter in the line account database is called to select the route with the highest priority, and a route switching instruction is triggered;

[0035] S3.5, the finally determined route information, corresponding and associated storage to the local cache forms a matching result data set to provide data support for the detection report generation module.

[0036] As a further improvement of the technical solution, the detection report generated by the detection report generation module specifically includes:

[0037] Based on the train real-time running distance recorded by the data receiving and processing module and the theoretical path length of the corresponding route in the line account , the mean value of the whole positioning deviation is calculated , and the maximum deviation value, the minimum deviation value and the deviation distribution interval are also marked;

[0038] The total route switching number, the successful switching number and the misjudgment number of the route matching decision module are counted, wherein the misjudgment is the case that the subsequent passing and the real-time track circuit code sequence verify that the current route does not match the actual route, calculate the route switching success rate , and attach the data acquisition timestamp of each switching , the matching degree of the corresponding real-time code sequence and the expected code sequence and and deviation value ;

[0039] Based on the receiving record of the data receiving and processing module, the positioning data receiving completeness rate is calculated , and the running time and the number of abnormal restarts of the data receiving and processing module, the line account management module and the route matching decision module are counted, and the data integrity and system stability evaluation conclusion is generated.

[0040] The second purpose of the present application is to provide a detection car accurate positioning method based on multi-channel wireless transmission, based on the above-mentioned detection car accurate positioning system based on multi-channel wireless transmission, comprising the following steps:

[0041] S1, collect the positioning data output by LKJ and TAX, and send the collected positioning data to the receiving end in the detection car in a concurrent redundant mode through the built-in at least two LoRa wireless communication modules working at different frequency points;

[0042] S2, receiving the positioning data sent by the sending end, sequentially performing checking, deduplication and fusion processing on the same data packets from different channels; firstly, adopting CRC16 cyclic redundancy check mechanism to remove data packets with damaged data, then identifying and deleting repeated data packets based on the positioning data timestamp and unique sequence number, finally, taking the data packet with the highest field integrity as the reference to complete the missing fields and correct the abnormal fields, forming the final fusion positioning data and broadcasting;

[0043] S3, receiving the final fusion positioning data, extracting the real-time train running distance, real-time track circuit code sequence and data collection timestamp; calling the theoretical path length, expected track circuit code sequence and route priority parameters of each route in the pre-stored line account database, calculating the deviation value of the real-time running distance and the theoretical path length, and the matching degree of the real-time track circuit code sequence and the expected track circuit code sequence, after removing the routes with deviation value exceeding the set deviation threshold, automatically performing route switching decision according to the matching degree and route priority;

[0044] S4, based on the deviation statistics of real-time running distance and theoretical path length, route switching result, positioning data reception integrity and the running state of each part of the system, automatically generating a standardized detection report.

[0045] Compared with the prior art, the beneficial effects of the present application are:

[0046] 1. The present application improves the stability and integrity of the positioning data transmission in the signal shielding area such as tunnel through the concurrent transmission of multi-channel LoRa wireless communication module, CRC16 cyclic redundancy check and data deduplication and fusion processing, solves the problem of easy packet loss interruption and difficult to guarantee data integrity in the prior art single channel transmission;

[0047] 2. The route switching decision algorithm based on train real-time running distance deviation, track circuit code sequence matching and route priority of the present application realizes the automation of route switching, avoids the lag and misjudgment of artificial presetting, solves the problem of route switching relying on manual operation, low efficiency and easy to cause positioning deviation;

[0048] 3. The multi-dimensional route matching of track circuit code sequence and mileage parameters of the present application improves the matching accuracy of positioning data and line account; at the same time, through the power and communication isolation design of the positioning collection module and TAX box, the interference hidden danger of equipment integration to the operation of original equipment is eliminated, and the problems of insufficient positioning accuracy and poor equipment compatibility are solved. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is the schematic diagram of the system framework of the present application;

[0050] Figure 2This is a schematic diagram of the method steps of the present invention;

[0051] The meanings of the labels in the diagram are as follows:

[0052] 1. Positioning and transmitting unit; 11. Isolation power supply module; 12. Communication isolation module; 13. Microcontroller module; 14. LoRa wireless communication module;

[0053] 2. Positioning and receiving unit;

[0054] 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

[0055] 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.

[0056] like Figure 1 As shown, this embodiment provides a precise positioning system for a detection vehicle based on multi-channel wireless transmission, including:

[0057] 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.

[0058] 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.

[0059] 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:

[0060] The isolated power supply 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Specifically, the micro control module 13 adopts a low-power ARM Cortex-M core microcontroller, which has a sufficient capacity of Flash and RAM to meet the data processing and caching requirements; its minimum system includes a main crystal oscillator (providing a clock signal), a real-time clock oscillator (used to generate a timestamp), a reset circuit (to ensure stable reset during power fluctuations), and a Boot configuration interface (for easy firmware upgrade); through the UART interface, the LKJ / TAX positioning data transmitted by the communication isolation module 12 is received, and the data is packaged into a data frame containing packet_id, timestamp, sequence_num, data_payload, CRC16 check bit, and channel_id, and temporarily stored in the specified area of the Flash (with a cache depth supporting the storage of 1000 frames of data); a built-in independent watchdog is enabled, and the program is normally run when the watchdog is fed; if the program runs away, the communication times out, or the cache overflows, the watchdog triggers the positioning sending unit 1 to automatically reset and restore the system to normal work.

[0066] In this step, the LoRa wireless communication module 14 is electrically connected with the micro control module 13, and is used to send the positioning data processed by the micro control module 13; the LoRa wireless communication module 14 works at two different frequencies and uses the CRC16 cyclic redundancy check mechanism for data transmission, adds a check bit to each frame of positioning data, and synchronously outputs the same positioning data frame in a concurrent redundancy mode.

[0067] Specifically, the positioning sending unit 1 is built-in with two LoRa wireless communication modules 14, both of which work at the 470MHz frequency band, and the frequency point interval of the two modules meets the anti-interference requirement (such as ≥10MHz or engineering compliance interval); through independent UART interfaces, the modules are electrically connected with the micro control module 13 to receive the data frame packaged by the micro control module 13; a concurrent redundancy transmission mode is adopted, and the two modules synchronously receive and transmit the same data frame, with a transmission rate controlled at 8-10 frames per second; the CRC16 cyclic redundancy check mechanism is used for data transmission, the check range covers the core fields of the data frame, ensuring data integrity, and the transmission distance is ≥500 meters (in an open environment), meeting the wireless communication requirements of the detection vehicle and the locomotive.

[0068] The positioning receiving unit 2 is arranged in the detection vehicle, and is used to receive the positioning data sent by the positioning sending unit 1, and to perform check, 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;

[0069] The positioning receiving unit 2 adopts a wall-mounted case design and is installed on the inner wall of the detection vehicle (preferably in an area with less signal shielding and less vibration impact). The case is adapted to the internal installation space of the detection vehicle, and an AC-DC power adapter (input: AC 220V power supply of the detection vehicle, output: stable DC 12V voltage) is built-in to provide safe power supply for the internal circuit of the positioning receiving unit 2. The internal circuit includes a data receiving circuit, a data processing circuit, and a data broadcasting circuit, which are connected by on-board wires.

[0070] In this step, the positioning receiving unit 2 checks and removes duplicate data packets from different channels, including the following steps:

[0071] S2.1, classify the data packets carrying positioning data received by each channel according to the reception time sequence, extract the positioning data timestamp and unique sequence number recorded in each data packet, and establish a data packet-positioning data association identification list;

[0072] Specifically, the data receiving circuit synchronously receives data packets from the double LoRa channels of the positioning sending 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 packet, and establishes an internal storage association identification list of "data packet-time stamp-sequence number-reception time".

[0073] S2.2, use the CRC16 cyclic redundancy check mechanism to check the integrity of the positioning data carried in each data packet, and remove the data packets with failed check and damaged positioning data;

[0074] Specifically, the data processing circuit calls the CRC16 cyclic redundancy check algorithm to calculate the check value of the "positioning data payload part" of the data packet, and compares it with the self-checking bit of the data packet. If the check fails, the data packet is deleted, and if the check passes, it is temporarily stored in the "de-duplication area" of the internal storage.

[0075] S2.3, based on the association identification list, compare the positioning data timestamps and sequence numbers corresponding to the data packets from different channels to identify duplicate data packets carrying the same positioning data;

[0076] Specifically, the data processing circuit uses "timestamp + sequence number" as the unique identifier of the same batch of data, compares the data packets from different channels in the "de-duplication area", and marks the duplicate data packets with the same timestamp and sequence number.

[0077] S2.4, keep the data packet with the earliest reception time and the positioning data check passed among the duplicate data packets, and delete the remaining duplicate data packets, to form a data packet set containing only unique valid positioning data.

[0078] In this step, the positioning receiving unit 2 fuses the same data packets from different channels, including the following steps:

[0079] S2.5, from the verified and deduplicated data packet set, extract all valid data packets carrying the same batch of positioning data, parse the field structure of the positioning data in each data packet, and count the completeness of each field;

[0080] Specifically, the valid data packets of the same batch of positioning data are extracted from the "to-be-fused area", the positioning data fields of each data packet are parsed, the completeness of each field is counted through "field existence + format compliance detection", and the results are temporarily stored in the "log area" in the internal storage.

[0081] S2.6, select the data packet with the highest field completeness as the reference data packet, and confirm the contents of the remaining data packets consistent with the reference data packet fields, and mark the missing or abnormal fields in the remaining data packets;

[0082] Specifically, the reference data packet is selected according to the "highest field completeness", and the remaining data packets are compared with the reference packet fields one by one, the consistent fields are marked as "confirmed", and the missing / abnormal fields are marked as "to be completed / modified", and the marking results are updated to the "log area".

[0083] S2.7, based on the complete fields of the reference data packet, complete the missing fields of the remaining data packets of the same batch, and modify the abnormal fields according to the corresponding fields of the reference data packet to form the preliminary fused positioning data;

[0084] S2.8, cross-check the preliminary fused positioning data to confirm the consistency of the key fields, generate the final fused positioning data in a standardized format, and encapsulate it as a unified data packet and broadcast it to the detection and analysis unit 3.

[0085] Further, the data processing circuit of the positioning receiving unit 2 transmits the "standardized data packet" to the data broadcast circuit; the data broadcast circuit uses an industrial RS485 interface, establishes communication with the RS485 interface of the detection and analysis unit 3, and sends data in "timed multicast" (broadcast period synchronized with the positioning sending unit 1); built-in "sending confirmation mechanism": after sending, wait for the reception confirmation code, if timeout, resend (re-send ≤2 times), if 2 re-sending still has no feedback, transmit the fault information to the data processing circuit and record it to the "log area".

[0086] The detection analysis unit 3 is used for receiving and processing the positioning data broadcast by the positioning receiving unit 2, and internally pre-stores a line account database containing theoretical path lengths of multiple routes and expected track circuit code sequence sequences; the detection analysis unit 3 automatically performs the route switching decision 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 sequence in the line account database, and automatically generates an analysis report after the detection ends.

[0087] Specifically, the detection analysis unit 3 is designed in a rack server, installed in a standard cabinet in the detection vehicle control room, powered by AC 220V vehicle power supply, and internally provided with a redundant power module to ensure continuous operation. The data receiving and processing module 31, the line account management module 32, the route matching decision module 33 and the detection report generation module 34 realize data interaction through an industrial Ethernet switch. The core function is to receive the fusion positioning data broadcast by the positioning receiving unit 2, complete data analysis, account calling, route matching decision through the cooperation of each module, automatically perform route switching and generate a standardized detection report.

[0088] In this step, the detection analysis unit 3 includes a data receiving and processing module 31, a line account management module 32, a route matching decision module 33 and a detection report generation module 34, wherein:

[0089] The data receiving and processing module 31 is used for receiving the fusion positioning data broadcast by the positioning receiving unit 2, and analyzing and extracting the real-time train travel distance , the real-time track circuit code sequence and the data acquisition timestamp .

[0090] Specifically, the data receiving and processing module 31 adopts Advantech PCI-1680U industrial RS485 serial communication card (4 independent interfaces, baud rate 1200bps-115200bps adjustable), is connected with the broadcast circuit of the positioning receiving unit 2 through shielded twisted pair (wire diameter 0.5mm², shielding layer grounded in accordance with anti-interference design specification), and is adapted to the strong electromagnetic environment of the detection vehicle; the driver program is based on the real-time Linux system RT-UART protocol, and the interrupt response time is adapted to the data receiving demand in the high-speed moving scene, so as to avoid data packet loss in high-speed moving; after the data receiving and processing module 31 receives the “standardized data packet”, the mileage jump is first suppressed through sliding window filtering, and the formula is as follows:

[0091] ;

[0092] Among them, is the original real-time train travel distance obtained by the positioning receiving unit 2, represents the real-time train travel distance after the sliding window filtering, Stable mileage data obtained after sliding window filtering For sliding window length (speed ≤80km / h , >80km / h ), For the time original mileage data;

[0093] Then verify the data sequence by time stamp-mileage double anchoring, the formula is as follows:

[0094] ;

[0095] ;

[0096] Wherein is the inter-frame timestamp difference, is the maximum sending period of the positioning sending unit 1 (0.125s, consistent with the sending end design), is the inter-frame mileage difference, is the maximum speed of the detection vehicle (≈33.33m / s, consistent with the running speed specification of the railway detection vehicle);

[0097] Finally, the parsed , (code sequence string), is stored in the local SQLite database in the format of , and is pushed to the route matching decision module 33 through the UDP protocol, and the transmission delay meets the real-time interaction requirement of the positioning data.

[0098] The line account management module 32 is used for storing and updating the line account database, and the line account database includes the unique identification of each route, the theoretical path length , the expected track circuit code sequence and the route priority parameter;

[0099] Specifically, the line account management module 32 uses Samsung 870EVO2TB industrial-grade SSD (MTBF≥200 million hours, consistent with the storage reliability requirement of industrial equipment) as the storage carrier, and built-in MySQL8.0 database (InnoDB transaction engine guarantees data consistency) to build a “route-code sequence-priority” three-dimensional account model, and the core table structure includes route information table and code sequence table; in order to adapt to the dynamic adjustment of priority in the transportation scene, the following formula is used to calculate the dynamic priority:

[0100] ;

[0101] Wherein is the dynamic priority (1-10 integer), 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;

[0102] 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.

[0103] 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;

[0104] 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.

[0105] In this step, the matching calculation algorithm of the route matching decision module 33 includes the following steps:

[0106] 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:

[0107] ;

[0108] ;

[0109] 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 For each candidate route, the theoretical path length in the associated line account is calculated , the expected track circuit code sequence .

[0110] S3.2, for each candidate route , the deviation value of the real-time running distance from the theoretical path length is calculated , a deviation threshold is set , the candidate route that exceeds the deviation threshold is removed, and a route subset that meets the deviation requirement is retained ;

[0111] Specifically, for each candidate route , the deviation value of the real-time running distance from the theoretical path length is calculated , and a deviation threshold is set (combined with the scene setting, such as station , section ), and a route subset that meets the deviation requirement is screened out . The deviation calculation formula is as follows:

[0112] .

[0113] S3.3, for each route in the route subset , the consistency with the route is compared , and the matching degree of the real-time code sequence and the expected code sequence is calculated ;

[0114] Specifically, for each route in the route subset , the matching degree of the real-time track circuit code sequence and the expected track circuit code sequence is compared , and the formula is as follows:

[0115] ;

[0116] Wherein, the number of code sequence fields consistent with ; (or , the total number of code sequence fields with the same length).

[0117] S3.4, if the route 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;

[0118] 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.

[0119] 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:

[0120] 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.

[0121] Specifically, based on the matching result dataset of the route matching decision module 33, the average positioning deviation throughout the entire process is statistically analyzed. Maximum deviation value Minimum deviation value The formula for calculating the mean deviation is as follows:

[0122] ;

[0123] in, This represents the total number of valid deviation data.

[0124] 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 ;

[0125] Specifically, calculate the route handover success rate. , the formula is as follows:

[0126] ;

[0127] wherein, represents the number of successful switching times; represents the total number of circuit switching times.

[0128] Based on the receiving record of the data receiving processing module 31, the positioning data receiving completeness rate is calculated At the same time, the running time and the number of abnormal restarts of the data receiving processing module 31, the line account management module 32, and the circuit matching decision module 33 are counted, and the data integrity and system stability evaluation conclusion is generated.

[0129] Specifically, the positioning data receiving completeness rate is calculated , the formula is as follows:

[0130] ;

[0131] wherein, represents the number of received data packets; represents the total number of sending frames of the positioning sending unit 1.

[0132] As shown in Figure 2 , the embodiment also provides a detection vehicle accurate positioning method based on multi-channel wireless transmission, based on the above-mentioned detection vehicle accurate positioning system based on multi-channel wireless transmission, comprising the following steps:

[0133] S1, collect the positioning data output by LKJ and TAX, and send the collected positioning data to the receiving end in the detection vehicle through at least two LoRa wireless communication modules 14 working at different frequency points in a concurrent redundant mode;

[0134] S2, receive the positioning data sent by the sending end, and sequentially perform checking, deduplication and fusion processing on the same data packets from different channels; first, the CRC16 cyclic redundancy check mechanism is used to eliminate damaged data packets, then the positioning data timestamp and unique sequence number are used to identify and delete duplicate data packets, finally, the data packet with the highest field completeness is used as a reference to complete the missing fields and correct the abnormal fields, to form the final fusion positioning data and broadcast;

[0135] S3, receiving the final fusion positioning data, extracting the train real-time running distance, real-time track circuit code sequence and data collection timestamp; calling the pre-stored route account database of each route theoretical path length, expected track circuit code sequence and route priority parameters, calculating the deviation value of real-time running distance and theoretical path length, the matching degree of real-time track circuit code sequence and expected track circuit code sequence, eliminating the route whose deviation value exceeds the set deviation threshold, and automatically executing the route switching decision according to the matching degree and route priority;

[0136] S4, based on the deviation statistics of real-time running distance and theoretical path length, route switching result, positioning data receiving completeness and the running state of each part of the system, automatically generating a standardized detection report.

[0137] Those of ordinary skill in the art can understand that the process of implementing all or part of the steps of the above-mentioned embodiments can be completed by hardware, or by program to instruct relevant hardware to complete.

[0138] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application 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, selects 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 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.

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