Transponder low altitude inspection test system and method

Abstract

The embodiment of the specification provides a transponder low-altitude patrol test system and method, wherein the system comprises: a ground control center configured to send a detection task to a UAV, monitor a flight state of the UAV, receive detection data and accurate positioning data sent by the UAV, and perform recursive positioning on a milestone according to the detection data and the accurate positioning data; a milestone configured to serve as an identification facility along a railway line; the UAV configured to communicate with a transponder portable tool according to the detection task, take a photo of the milestone along the railway line and identify a mileage mark thereof, perform centimeter-level positioning, send the accurate positioning data to the ground control center, accurately hover at a specified position, and perform real-time transmission of a photographed image; and the transponder portable tool configured to read and write a message of the transponder and perform message verification.

Description

Technical Field

[0001] This document relates to the field of computer technology, and in particular to a low-altitude inspection and testing system and method for transponders. Background Technology

[0002] A balise is a key piece of equipment in a modern railway signaling system, primarily used to transmit important data to trains, such as location information, track parameters, and temporary speed limits. A balise system typically consists of two parts: a ground balise and a vehicle-mounted transponder transmission module (BTM). The ground balise is installed on the track centerline and transmits information to the vehicle-mounted equipment via electromagnetic coupling when a train passes.

[0003] During railway construction, operation, and maintenance, it is necessary to regularly inspect and verify the installation location and message information of transponders to ensure train operation safety. Traditional inspection methods mainly rely on manual labor to carry inspection equipment along the track and inspect each transponder one by one. This method has problems such as low efficiency, high labor intensity, and the accuracy of inspection being affected by human factors.

[0004] Currently, product and parameter calibration is done manually, without an automated testing system. Specifically, the existing testing method involves a person carrying a transponder message tool, a measuring tape, and a GPS positioning device. Using a kilometer marker as a reference, the person manually measures the physical location of the transponder using the measuring tape, with GPS positioning used for auxiliary correction. Then, the internal mileage information is read using the transponder message tool, and the message content and mileage information are manually verified. For most transponders, this process is time-consuming, prone to errors in message verification, and inefficient.

[0005] While rail transit inspection technology is constantly developing, various inspection systems still have significant limitations. As a traditional primary inspection method, onboard rail inspection systems face the severe challenge of limited inspection windows. These limited windows severely restrict inspection efficiency, especially on newly built lines before joint commissioning and testing. Furthermore, the purchase and maintenance costs of rail inspection vehicles are extremely high, requiring specialized drivers and operators, resulting in high costs per inspection. Their limitation of operating only along fixed tracks and lack of flexibility in route adjustments makes inspection of branch lines and dedicated lines uneconomical, difficult to schedule, and slow in response. More seriously, the high speed of the vehicles increases the likelihood of missed inspections, and their ability to distinguish densely packed transponder arrays is limited, leading to particularly poor inspection results in complex turnout areas. While portable detectors have somewhat compensated for the shortcomings of vehicle-mounted systems, they also have significant inherent problems. Inspection personnel must walk on the track for extended periods, resulting in extremely high labor intensity. Even with devices touted as portable, carrying them for long periods remains strenuous, especially in inclement weather. More importantly, personnel working in the track area pose serious safety hazards, requiring dedicated protective gear, and the risks increase exponentially at night. Furthermore, manual walking inspections are slow, with extremely limited daily inspection capacity. The need to stop at each transponder location for inspection makes data recording and processing time-consuming and laborious, resulting in severely low efficiency. Additionally, manual positioning accuracy is poor, with large mileage errors, leading to missed and incorrect detections. Inspection results are heavily influenced by operator experience, and data processing lags are significant; only basic information can be viewed on-site, with detailed data analysis requiring post-processing, making real-time comparison and anomaly warning difficult. While track-mounted robot systems, which have emerged in recent years, represent a new direction in technological development, their endurance is limited, they require track space, and maintenance is complex. Summary of the Invention

[0006] The purpose of this invention is to provide a low-altitude inspection and testing system and method for transponders, aiming to solve the above-mentioned problems in the prior art.

[0007] This invention provides a low-altitude inspection and testing system for transponders, comprising:

[0008] The ground control center is used to send detection tasks to the UAV, monitor the flight status of the UAV, receive detection data and precise positioning data sent by the UAV, and perform recursive positioning based on the detection data and precise positioning data at milestones.

[0009] Milestones are used as markers along railway lines to pinpoint their precise locations.

[0010] The drone is used to attach a portable transponder tool. According to the detection task, it communicates with the portable transponder tool, takes aerial photos of railway milestones and identifies their mileage markers, performs centimeter-level positioning, sends the precise positioning data to the ground control center, maintains precise hovering at a designated location, transmits the captured images in real time, receives the detection data sent by the portable transponder tool and performs verification and analysis, and sends the verification results and the detection data to the ground control center.

[0011] A portable transponder tool that connects to a drone is used to read and write transponder messages, perform message verification, receive operation commands from the drone, and communicate with the drone for detection data.

[0012] This invention provides a method for low-altitude inspection testing of transponders, used in the aforementioned low-altitude inspection testing system for transponders. The method includes:

[0013] The ground control center sends detection tasks to the UAV, monitors the UAV's flight status, receives detection data and precise positioning data sent by the UAV, and performs recursive positioning at milestones based on the detection data and precise positioning data.

[0014] Milestones are used as markers along the railway line for precise location identification;

[0015] The drone communicates with the portable transponder tool according to the detection task, takes aerial photos of the milestones along the railway line and identifies their mileage markers, performs centimeter-level positioning, sends the precise positioning data to the ground control center, maintains precise hovering at the designated location, transmits the captured images in real time, receives the detection data sent by the portable transponder tool and performs verification and analysis, and sends the verification results and the detection data to the ground control center.

[0016] The transponder's messages are read and written using a portable transponder tool, and message verification is performed. The tool also receives the operation commands from the UAV and communicates with the UAV to exchange detection data.

[0017] By employing embodiments of the present invention, detection efficiency is improved by rapidly deploying a system that is not limited by traditional tracks, minimizing interference with normal railway operations; positioning accuracy is improved by overcoming the technical bottlenecks of traditional detection methods, enabling high-precision measurement of transponder position and mileage information; the level of intelligence is enhanced by constructing an intelligent system capable of real-time analysis and processing of detection data, automatic comparison and verification, and timely early warning of anomalies; and reliance on manual labor is reduced by shifting from manual detection to automatic intelligent detection, thereby comprehensively improving detection efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in one or more embodiments of this specification or in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a low-altitude inspection and testing system for transponders according to an embodiment of the present invention;

[0020] Figure 2 This is an overall workflow diagram of the transponder low-altitude inspection and testing system according to an embodiment of the present invention;

[0021] Figure 3 This is an algorithm flowchart of the transponder low-altitude inspection and testing system according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the actual low-altitude inspection and testing system for transponders according to an embodiment of the present invention;

[0023] Figure 5 This is a flowchart of the transponder low-altitude inspection test method according to an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this document.

[0025] System Implementation Examples

[0026] According to an embodiment of the present invention, a low-altitude inspection and testing system for transponders is provided, which combines real-time dynamic carrier phase differential technology (RTK), portable transponder reading technology and kilometer marker recursive algorithm to realize automated and intelligent detection of transponder installation location and message information. Figure 1 This is a schematic diagram of a low-altitude inspection and testing system for transponders according to an embodiment of the present invention, as shown below. Figure 1 As shown, the transponder low-altitude inspection and testing system according to an embodiment of the present invention specifically includes:

[0027] The ground control center is used to send detection tasks to the UAV, monitor the flight status of the UAV, receive detection data and precise positioning data sent by the UAV, and perform recursive positioning based on the detection data and precise positioning data at milestones.

[0028] The ground control center is specifically used for: building upon a distributed architecture to form a complete data flow processing link from the data acquisition layer to the application service layer, performing automatic transponder information comparison, multi-level anomaly alarm mechanisms, and data visualization functions. The ground control center specifically includes:

[0029] The flight control module is responsible for real-time flight status monitoring, flight mode switching, and emergency control response.

[0030] The task management module is used to provide full lifecycle management of detection tasks, which specifically includes: task creation, execution monitoring and historical query functions;

[0031] The data display module is used to realize the real-time visualization of detection data and anomaly alarms. Specifically, the data display module is used to: adopt a multi-window layout concept, realize the classification and display of information through four dedicated windows: map, data, control and status, and support interface customization and touch operation functions.

[0032] The system configuration module is used for parameter settings, permission management, and system maintenance.

[0033] The ground control center is specifically used for:

[0034] Obtain the mileage markers of the route or the RTK coordinates (X0, Y0, Z0) and mileage value K0 of the preset location, and establish a local coordinate system with the route direction as the x-axis;

[0035] For the detected transponder i, whose installation location is known to be Ki_design, obtain the RTK coordinates (Xi, Yi, Zi) and calculate the distance Di to the nearest milestone according to Formula 1, where (Xref, Yref, Zref) is initially assigned the value (X0, Y0, Z0):

[0036] Formula 1;

[0037] The mileage value Ki is calculated according to Formula 2, where the angle θ is the spatial angle between the two locations:

[0038] Formula 2;

[0039] Error correction is performed according to Formula 3:

[0040] ΔKi = Ki - Ki_design formula 3;

[0041] Update the reference point. If |ΔKi| < threshold, then Xref = Xi, Yref = Yi, Kref = Ki, where threshold is the set distance threshold deviation.

[0042] Fit the error curve by the least squares method, perform automatic compensation for the system error, and obtain the actual installation position coordinates of the transponder after error compensation.

[0043] When the actual installation position coordinates of the transponder after error compensation are obtained, compare them with the positions parsed from the messages read by the transponder portable tool, and compare the comparison result with the set engineering deviation threshold. If it exceeds the threshold, directly send an alarm message. If it does not exceed the threshold, perform hierarchical management on the deviation information.

[0044] Milestones are used as identification facilities along the railway for precise position positioning.

[0045] The unmanned aerial vehicle (UAV) is used to externally hang the transponder portable tool, communicate with the transponder portable tool according to the detection task, aerial photograph the milestones along the railway and identify their mileage markings, perform centimeter-level precision positioning, send the precise positioning data to the ground control center, maintain precise hovering at the specified position, perform real-time transmission of the captured images, receive the detection data sent by the transponder portable tool and perform inspection and analysis, and send the inspection results and the detection data to the ground control center.

[0046] The transponder portable tool is connected to the UAV and is used to read and write the messages of the transponder and perform message verification, receive the operation instructions of the UAV, and communicate with the UAV for detection data.

[0047] As can be seen from the above description, the technical solution of the embodiment of the present invention first applies the low-altitude UAV inspection technology to the field of railway transponder detection, breaking through the limitations of the traditional ground detection method of transponders. By carrying a specially designed portable transponder reading payload, non-contact detection of ground transponders from the air is achieved. An innovative recursive algorithm based on RTK positioning information and the physical position of the milestone is proposed to achieve centimeter-level transponder position calibration. This algorithm can automatically identify and correct positioning errors to ensure the accuracy of mileage information. A dedicated data processing system is developed, which can parse the transponder message information in real time and automatically compare it with the design database, realizing the intelligent analysis of detection results and the function of abnormal alarm. The hardware device, communication protocol, data processing algorithm and user interface are deeply integrated to form a complete set of automated detection solutions, reducing manual input, lowering the construction difficulty, and at the same time greatly improving the detection efficiency and accuracy.

[0048] The key technical aspects of this invention are mainly reflected in the deep integration and synergistic optimization of three core innovative areas. First, the air transponder signal reading technology, as the core innovation of the entire system, employs a specially designed high-gain directional antenna array combined with advanced digital signal processing algorithms. Through a series of complex signal processing steps, including multi-band signal acquisition, filtering and noise reduction, modulation and demodulation, and error correction, it achieves high-precision real-time reading of air transponder signals. This technical solution has reached industry-leading levels in key performance indicators such as signal recognition accuracy, anti-interference capability, and response speed. Therefore, it is necessary to focus on protecting the intellectual property rights of the related antenna structure design, signal processing algorithms, and hardware implementation scheme. Second, the RTK and milestone recursive fusion positioning algorithm represents a major breakthrough in high-precision positioning technology. This algorithm cleverly combines the centimeter-level positioning accuracy of Real-Time Dynamic Carrier Phase Differential (RTK) technology with the absolute position reference of milestone markers. By establishing a recursive filter and dynamic weight allocation mechanism, it achieves optimal fusion of multi-source positioning information. Simultaneously, it integrates advanced mileage calculation methods and multi-level error compensation and correction mechanisms, effectively eliminating accumulated errors, systematic deviations, and environmental interference, ensuring the stability and reliability of positioning accuracy during long-term operation. Finally, the intelligent task planning and execution system, through the construction of an efficient distributed data processing architecture, realizes real-time acquisition, preprocessing, feature extraction, and pattern recognition of massive sensor data. Its core intelligent comparison algorithm, based on deep learning and artificial intelligence technologies, can automatically identify and analyze complex operating environments and task requirements, formulate optimal execution strategies and path planning schemes, and is equipped with an advanced real-time anomaly detection mechanism. Through multi-dimensional monitoring, threshold judgment, trend analysis, and early warning response modules, it ensures the safe and stable operation of the entire system under various complex working conditions.

[0049] This invention proposes a system design that can verify the location information in the transponder installation layout, milestones, and message information, and report the detection results based on the information. Through a systematic approach, the difficulty of the detection items can be reduced and the detection efficiency can be improved.

[0050] The technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0051] The system consists of four subsystems: ground control center, milestones, UAVs, and transponder-based portable tools (payloads). The system framework is as follows: Figure 1 As shown.

[0052] The ground control center, serving as the core command center of the entire UAV detection system, integrates multiple key functional modules to ensure efficient system operation and precise control. The system mainly consists of four core modules: the flight control module, responsible for real-time flight status monitoring, flight mode switching, and emergency control response; the task management module, providing full lifecycle management of detection tasks, including task creation, execution monitoring, and historical query functions; the data display module, enabling real-time visualization of detection data and anomaly alarms; and the system configuration module, ensuring standardized operation of parameter settings, access control, and system maintenance. In terms of user interface design, the system adopts a modern multi-window layout concept, using four dedicated windows for map, data, control, and status to categorize and display information, while also supporting interface customization and touch operation. The underlying data processing and management subsystem is built on a distributed architecture, forming a complete data flow processing link from the data acquisition layer to the application service layer. It also implements automatic transponder information comparison, a multi-level anomaly alarm mechanism, and rich data visualization functions, providing reliable technical support and operational assurance for UAV detection operations.

[0053] Mileage markers, as crucial identification facilities along railway lines, play a vital role in modern railway transportation systems. These markers primarily function to provide precise location information, offering accurate mileage references for train drivers, dispatchers, and maintenance personnel, thus effectively assisting in train operation scheduling, safety management, and equipment maintenance. In operational management, kilometer markers are not only used to develop train timetables and calculate travel distances and times, but also work closely with signal control systems to help determine the precise locations of various railway equipment, providing reliable positioning data for automatic train control systems. Furthermore, these markers have irreplaceable value in emergency response, providing precise location information for accident reports, facilitating the rapid arrival of rescue teams at the scene. According to railway technical standards, kilometer markers typically have one main marker per kilometer, with auxiliary markers every 100 meters or 500 meters, and specialized markers at key locations such as stations, bridges, and tunnels. In summary, railway kilometer markers, as an important component of the railway infrastructure system, are of irreplaceable importance in ensuring railway transportation safety, improving operational efficiency, and standardizing line management.

[0054] A balise is a key piece of equipment in a modern railway signaling system, primarily used to transmit important data to trains, such as location information, track parameters, and temporary speed limits. Ground balises are installed on the track centerline and transmit information to onboard equipment via electromagnetic coupling when a train passes.

[0055] The drone adopts a lightweight design concept and is equipped with a pure electric power system, possessing excellent flight performance and handling stability. It can carry an external payload of up to 5 kg and communicate with transponder message reading and writing tools, enabling aerial photography of railway line signs and identification of mileage markers. The drone integrates RTK high-precision positioning technology, achieving centimeter-level positioning accuracy, ensuring the accuracy and repeatability of its flight trajectory, and maintaining precise hovering at designated locations, providing a reliable platform for precision operations. The drone has a real-time image transmission system with a transmission distance of up to 20 kilometers, enabling stable long-distance transmission of high-definition video signals, providing strong technical support for applications such as remote monitoring, inspection operations, and emergency response.

[0056] The payload (portable transponder tool), as a specialized technical device, primarily undertakes the important function of reading and writing transponder messages. This tool possesses comprehensive operational capabilities for different types of transponders, enabling general functions such as reading messages from various European standard transponders, performing complete message verification, accepting UAV operating commands, and communicating detection results with the UAV.

[0057] Overall workflow diagram as follows Figure 2 As shown, preparations are made before a flight mission, including selecting the task to be performed, route generation, parameter configuration, pre-flight preparation, equipment connection, and overall system self-check. During the execution phase, the aircraft travels to the starting point, typically a preset known location or a mileage marker location. Upon arrival, it identifies the mileage marker location, records the current location's RTK parameters, and transmits them to the ground control center. During the detection phase, such as... Figure 4 As shown, the drone carries a payload, flies above the transponder and hovers, activates the transponder to read its message information, and the drone can perform real-time verification and analysis of individual data. It also transmits the detection results and raw data to the ground center. After the ground center receives the data, it sends a mission end command to the drone, which then returns to base and lands. At the same time, the ground control center summarizes the data, generates a report, and finally archives the data to complete the entire flight mission.

[0058] To improve positioning accuracy and odometer calculation accuracy, this system proposes a milestone-based recursive positioning algorithm, as follows:

[0059] 1. Initialization Phase

[0060] Obtain the RTK coordinates (X0, Y0, Z0) and mileage value K0 of the route milestone (mileage marker) or preset location. The mileage value and RTK coordinate position can be interchanged. At the same time, establish a local coordinate system with the route direction as the x-axis.

[0061] 2. Recursive calculation

[0062] For the detected transponder i, its installation location is already known to be Ki_design:

[0063] 1. Obtain RTK coordinates (Xi, Yi, Zi).

[0064] 2. Calculate the distance to the nearest milestone, where (Xref, Yref, Zref) is initially assigned the value (X0, Y0, Z0):

[0065]

[0066] 3. Calculate the mileage value, where angle θ is the spatial angle between the two locations:

[0067]

[0068] 4. Error Correction:

[0069] ΔKi = Ki - Ki_design

[0070] 5. Update reference points:

[0071] if |ΔKi| <threshold:

[0072] Xref = Xi, Yref = Yi, Kref = Ki

[0073] 3. Error Compensation

[0074] Automatic compensation of system errors is achieved by fitting the error curve using the least squares method. The algorithm flowchart is as follows: Figure 3 As shown. When the actual installation location coordinates of the transponder after error compensation are obtained, they are compared with the location parsed from the message read by the transponder portable tool, and the comparison result is compared with the set engineering deviation threshold. If the threshold is exceeded, an alarm message will be issued directly. If the threshold is not exceeded, the deviation information is managed in a hierarchical manner to facilitate subsequent management and maintenance.

[0075] The intelligent track inspection system based on advanced technology demonstrates significant advantages in multiple dimensions. In terms of efficiency, the system achieves a substantial increase in inspection speed. By not occupying track resources and supporting multi-point parallel operations, it effectively reduces labor costs and improves operational efficiency. The accuracy advantage is reflected in significantly improved positioning accuracy and enhanced inspection reliability. The automated inspection mechanism effectively reduces human error, and combined with multiple data verification mechanisms and real-time anomaly detection alarm functions, it ensures the accuracy of inspection results. Regarding data integrity, the system achieves automatic recording of data throughout the entire process, with fully traceable inspection trajectories and support for data playback analysis, providing a reliable basis for subsequent decision-making. Functional advantages are prominently displayed in its high level of intelligence, possessing intelligent data analysis and comparison capabilities, generating inspection reports in real time, and adapting to the inspection needs of various complex terrain environments. In terms of economic benefits, the system's equipment cost is far lower than that of traditional track inspection vehicles. It eliminates the need for dedicated track facilities, significantly reducing maintenance and operating costs. The significant reduction in energy consumption costs and substantial savings in labor costs further enhance its economic value.

[0076] Method Implementation Examples

[0077] According to an embodiment of the present invention, a method for low-altitude inspection testing of transponders is provided, which is used in the aforementioned low-altitude inspection testing system for transponders. Figure 5 This is a flowchart of the transponder low-altitude inspection test method according to an embodiment of the present invention, as follows: Figure 5 As shown, the transponder low-altitude inspection test method according to an embodiment of the present invention specifically includes:

[0078] Step S501: The ground control center sends a detection task to the UAV to monitor the UAV's flight status, receives the detection data and precise positioning data sent by the UAV, and performs recursive positioning based on the detection data and precise positioning data. The ground control center is built on a distributed architecture, forming a complete data flow processing link from the data acquisition layer to the application service layer, and performs automatic comparison of transponder information, multi-level anomaly alarm mechanism, and data visualization function.

[0079] Step S501 specifically includes:

[0080] The flight control module is responsible for real-time flight status monitoring, flight mode switching, and emergency control response.

[0081] The task management module provides full lifecycle management of detection tasks, which specifically includes: task creation, execution monitoring, and historical query functions.

[0082] The real-time visualization and abnormal alarm of the detection data are realized through the data display module; specifically, the concept of multi-window layout is adopted, and the classification display of information is realized through four dedicated windows of map, data, control, and status, and the interface customization and touch operation functions are supported.

[0083] Parameter settings, permission management, and system maintenance are carried out through the system configuration module.

[0084] Obtain the mileage identifier of the line or the RTK coordinates (X0, Y0, Z0) and mileage value K0 of the preset position, establish a local coordinate system, and take the line direction as the x-axis;

[0085] For the detected transponder i, knowing its installation position as Ki_design, obtain the RTK coordinates (Xi, Yi, Zi), and calculate the distance Di from the nearest milestone according to formula 1, where (Xref, Yref, Zref) is initially assigned as (X0, Y0, Z0):

[0086] Formula 1;

[0087] Calculate the mileage value Ki according to formula 2, and the angle θ is the spatial included angle between the two positions:

[0088] Formula 2;

[0089] Perform error correction according to formula 3:

[0090] ΔKi = Ki - Ki_design Formula 3;

[0091] Update the reference point. If |ΔKi| < threshold, then Xref = Xi, Yref = Yi, Kref = Ki, where threshold is the set distance threshold deviation;

[0092] Automatically compensate the system error by fitting the error curve with the least squares method;

[0093] When the actual installation position coordinates of the transponder after error compensation are obtained, compare them with the positions parsed from the message read by the transponder portable tool, and compare the comparison result with the set engineering deviation threshold. If it exceeds the threshold, directly send an alarm message. If it does not exceed the threshold, classify and manage the deviation information.

[0094] Step S502, use the milestone as the identification facility along the railway for accurate position positioning;

[0095] Step S503: The UAV communicates with the portable transponder according to the detection task, takes aerial photos of the milestones along the railway line and identifies their mileage markers, performs centimeter-level positioning, sends the precise positioning data to the ground control center, maintains precise hovering at the designated location, transmits the captured images in real time, receives the detection data sent by the portable transponder and performs verification and analysis, and sends the verification results and the detection data to the ground control center.

[0096] Step S504: Read and write transponder messages and verify messages using a portable transponder tool, receive operation commands from the UAV, and communicate with the UAV to exchange detection data.

[0097] The overall workflow is as follows Figure 2 As shown, preparations are made before a flight mission, including selecting the task to be performed, route generation, parameter configuration, pre-flight preparation, equipment connection, and overall system self-check. During the execution phase, the aircraft travels to the starting point, typically a preset known location or a mileage marker location. Upon arrival, it identifies the mileage marker location, records the current location's RTK parameters, and transmits them to the ground control center. During the detection phase, such as... Figure 4 As shown, the drone carries a payload, flies above the transponder and hovers, activates the transponder to read its message information, and the drone can perform real-time verification and analysis of individual data. It also transmits the detection results and raw data to the ground center. After the ground center receives the data, it sends a mission end command to the drone, which then returns to base and lands. At the same time, the ground control center summarizes the data, generates a report, and finally archives the data to complete the entire flight mission.

[0098] To improve positioning accuracy and odometer calculation accuracy, this system proposes a milestone-based recursive positioning algorithm, as follows:

[0099] 1. Initialization Phase

[0100] Obtain the RTK coordinates (X0, Y0, Z0) and mileage value K0 of the route milestones (mileage markers) or preset locations. The mileage value and RTK coordinates can be interchanged. Simultaneously, establish a local coordinate system with the route direction as the x-axis.

[0101] 2. Recursive calculation

[0102] For the detected transponder i, its installation location is already known to be Ki_design:

[0103] 1. Obtain RTK coordinates (Xi, Yi, Zi)

[0104] 2. Calculate the distance to the nearest milestone, where (Xref, Yref, Zref) is initially assigned the value (X0, Y0, Z0):

[0105]

[0106] 3. Calculate the mileage value, where angle θ is the spatial angle between the two locations:

[0107]

[0108] 4. Error Correction:

[0109] ΔKi = Ki - Ki_design

[0110] 5. Update reference points:

[0111] if |ΔKi| <threshold:

[0112] Xref = Xi, Yref = Yi, Kref = Ki

[0113] 3. Error Compensation

[0114] Automatic compensation of system errors is achieved by fitting the error curve using the least squares method. The algorithm flowchart is as follows: Figure 3 As shown. When the actual installation location coordinates of the transponder after error compensation are obtained, they are compared with the location parsed from the message read by the transponder portable tool, and the comparison result is compared with the set engineering deviation threshold. If the threshold is exceeded, an alarm message will be issued directly. If the threshold is not exceeded, the deviation information is managed in a hierarchical manner to facilitate subsequent management and maintenance.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-altitude inspection and testing system for transponders, characterized in that, include: The ground control center is used to send detection tasks to the UAV, monitor the flight status of the UAV, receive detection data and precise positioning data sent by the UAV, and perform milestone recursive positioning based on the detection data and precise positioning data. Milestones are used as markers along railway lines to pinpoint their exact location. The drone is used to attach a portable transponder tool. According to the detection task, it communicates with the portable transponder tool, takes aerial photos of railway milestones and identifies their mileage markers, performs centimeter-level positioning, sends the precise positioning data to the ground control center, maintains precise hovering at a designated location, takes images and transmits them in real time, receives the detection data sent by the portable transponder tool and performs verification and analysis, and sends the verification results and the detection data to the ground control center. A portable transponder tool that connects to a drone is used to read and write transponder messages, perform message verification, receive operation commands from the drone, and communicate with the drone for detection data.

2. The system according to claim 1, characterized in that, The ground control center is specifically used for: building a complete data flow processing link from the data acquisition layer to the application service layer based on a distributed architecture, performing automatic comparison of transponder information, multi-level anomaly alarm mechanism, and data visualization function.

3. The system according to claim 1, characterized in that, The ground control center specifically includes: The flight control module is responsible for real-time flight status monitoring, flight mode switching, and emergency control response. The task management module is used to provide full lifecycle management of detection tasks, which specifically includes: task creation, execution monitoring and historical query functions; The data display module is used to realize real-time visualization of detection data and anomaly alarms; The system configuration module is used for parameter settings, permission management, and system maintenance.

4. The system according to claim 3, characterized in that, The data display module is specifically used for: It adopts a multi-window layout method, using four dedicated windows for map, data, control and status to classify and display information, and supports interface customization and touch operation functions.

5. The system according to claim 1, characterized in that, The ground control center is specifically used for: Obtain the mileage markers of the route or the RTK coordinates (X0, Y0, Z0) and mileage value K0 of the preset location, and establish a local coordinate system with the route direction as the x-axis; For the detected transponder i, whose installation location is known to be Ki_design, obtain the RTK coordinates (Xi, Yi, Zi), and calculate the distance Di between the transponder i and the nearest milestone according to Formula 1, where (Xref, Yref, Zref) is initially assigned the value (X0, Y0, Z0): Formula 1: The mileage value Ki is calculated according to Formula 2, where the angle θ is the spatial angle between the two locations: Formula 2: Error correction is performed according to Formula 3: ΔKi = Ki - Ki_design formula 3; Update the reference point. If |ΔKi| < threshold, then Xref = Xi, Yref = Yi, Kref = Ki, where threshold is the set distance deviation threshold. The system error is automatically compensated by fitting the error curve using the least squares method. When the actual installation location coordinates of the transponder after error compensation are obtained, they are compared with the location coordinates obtained by parsing the message through the transponder portable tool. The comparison result is then compared with the set engineering deviation threshold. If the threshold is exceeded, an alarm message is issued. If the threshold is not exceeded, the deviation information is managed in a hierarchical manner.

6. A method for low-altitude inspection testing of transponders, characterized in that, The method for the transponder low-altitude inspection and testing system according to any one of claims 1 to 5 comprises: The ground control center sends detection tasks to the UAV, monitors the UAV's flight status, receives detection data and precise positioning data sent by the UAV, and performs recursive positioning at milestones based on the detection data and precise positioning data. Milestones are used as markers along the railway line for precise location identification; The drone communicates with the portable transponder tool according to the detection task, takes aerial photos of the milestones along the railway line and identifies their mileage markers, performs centimeter-level positioning, sends the precise positioning data to the ground control center, maintains precise hovering at the designated location, transmits the captured images in real time, receives the detection data sent by the portable transponder tool and performs verification and analysis, and sends the verification results and the detection data to the ground control center. The transponder's messages are read and written using a portable transponder tool, and message verification is performed. The tool also receives the operation commands from the UAV and communicates with the UAV to exchange detection data.

7. The method according to claim 6, characterized in that, The ground control center is built on a distributed architecture, forming a complete data flow processing link from the data acquisition layer to the application service layer, and performs automatic comparison of transponder information, multi-level anomaly alarm mechanism, and data visualization function.

8. The method according to claim 6, characterized in that, The ground control center sends detection tasks to the drone, monitors the drone's flight status, and receives detection data and precise positioning data from the drone. Specifically, this includes: The flight control module is responsible for real-time flight status monitoring, flight mode switching, and emergency control response. The task management module provides full lifecycle management of detection tasks, which specifically includes: task creation, execution monitoring, and historical query functions. The data display module enables real-time visualization of detection data and provides anomaly alarms. Parameter settings, permission management, and system maintenance are performed through the system configuration module.

9. The method according to claim 7, characterized in that, The real-time visualization of detection data achieved through the data display module specifically includes: It adopts a multi-window layout method, using four dedicated windows for map, data, control and status to classify and display information, and supports interface customization and touch operation functions.

10. The method according to claim 6, characterized in that, The step of performing milestone recursive positioning based on the detection data and the precise positioning data specifically includes: Obtain the mileage markers of the route or the RTK coordinates (X0, Y0, Z0) and mileage value K0 of the preset location, and establish a local coordinate system with the route direction as the x-axis; For the detected transponder i, whose installation location is known to be Ki_design, obtain the RTK coordinates (Xi, Yi, Zi), and calculate the distance Di between the transponder i and the nearest milestone according to Formula 1, where (Xref, Yref, Zref) is initially assigned the value (X0, Y0, Z0): Formula 1: The mileage value Ki is calculated according to Formula 2, where the angle θ is the spatial angle between the two locations: Formula 2: Error correction is performed according to Formula 3: ΔKi = Ki - Ki_design formula 3; Update the reference point. If |ΔKi| < threshold, then Xref = Xi, Yref = Yi, Kref = Ki, where threshold is the set distance deviation threshold. The system error is automatically compensated by fitting the error curve using the least squares method. When the actual installation location coordinates of the transponder after error compensation are obtained, they are compared with the location coordinates obtained by parsing the message through the transponder portable tool. The comparison result is then compared with the set engineering deviation threshold. If the threshold is exceeded, an alarm message is issued. If the threshold is not exceeded, the deviation information is managed in a hierarchical manner.

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