Public inspection mileage positioning method and system

Abstract

The invention relates to the field of public service infrastructure inspection, and particularly discloses a public service inspection mileage positioning method and system, and the method comprises the following steps: S1, obtaining mileage basic information; s2, displacement information and angular displacement information are obtained, so that the mileage basic information is corrected for the first time; s3, correcting the mileage basic information for the second time on the basis of a ballast bed electronic tag; s4, capturing and counting fixed features of the outer side of the steel rail based on a video stream, and correcting the mileage basic information for the third time; s5, performing fourth correction on the mileage basic information based on a positioning kilometer post of a tunnel wall; wherein the steps from S1 to S5 are executed when the inspection equipment runs on the track line. According to the system, data of various sensors such as a wheel built-in encoder, a digital inertial navigation module, an inspection camera, a visual monitoring camera and a tunnel inspection camera are combined, so that multi-source data are collaboratively fused, and a mileage measurement result is more accurate.

Description

Technical Field

[0001] The present application relates to the field of civil engineering infrastructure inspection, and specifically to a civil engineering inspection mileage positioning method and system. Background Art

[0002] Inspections of civil engineering infrastructure often rely on convenient, automated, and intelligent systems. Furthermore, because rail lines include tunnels, satellite positioning is not feasible. Currently, there are two common ways to install detection modules: one is to install them on the underside of electric trains, operating vehicles, and various types of construction vehicles, enabling immediate inspections as vehicles pass by, thereby improving inspection efficiency on civil engineering lines. The other is to install them on mobile inspection carts to inspect low-speed rail lines. Regardless of the installation method, high-precision alignment of mileage information is essential to ensure the accuracy of the detection alarm results.

[0003] Traditional positioning methods often combine track characteristics with methods such as sleeper counting to perform positioning. However, these methods have significant drawbacks when track conditions are complex. If special circumstances cause the counting process to fail, or if a monitoring camera malfunctions and counting is unsuccessful, the accuracy of mileage positioning cannot be guaranteed. Summary of the Invention

[0004] In view of this, the present invention provides a method and system for mileage positioning during civil engineering inspections, aiming to solve the problem of mileage positioning accuracy during civil engineering infrastructure inspections. Specifically, the technical solution of this application is as follows: A method for mileage positioning during a construction inspection comprises the following steps: S1: Get basic mileage information; S2: Acquire displacement information and angular displacement information to perform a first correction on the basic mileage information; S3: performing a second correction on the basic mileage information based on the roadbed electronic tag; S4: capturing and counting fixed features on the outer side of the rail based on the video stream, and performing a third correction on the basic mileage information; S5: performing a fourth correction on the basic mileage information based on the positioning kilometer mark on the tunnel wall; Wherein, the steps S1 to S5 are performed by the inspection equipment while the vehicle is traveling on the track line.

[0005] Furthermore, in S1, the basic mileage information is obtained based on the encoder: , Where D represents the current inspection distance, N represents the number of pulses output by the encoder per revolution, and C represents the wheel circumference. Wherein, the encoder is located inside the wheel.

[0006] Furthermore, in S2, the displacement information and angular displacement information are obtained based on a digital inertial navigation module to perform a first correction on the mileage basic information: S21: Integrating the acceleration data twice based on the digital inertial navigation module to obtain the displacement information; S22: Integrating the angular velocity data based on the digital inertial navigation module to obtain the angular displacement information; S23: interpolating the mileage basic information using the displacement information and the angular displacement information to perform a first correction.

[0007] Furthermore, the acceleration data includes acceleration data in three axes: X, Y, and Z.

[0008] Furthermore, in the second correction of the mileage basic information based on the roadbed electronic tag in S3, the roadbed electronic tag is identified by an inspection camera.

[0009] Furthermore, in S4, fixed features on the outer side of the rail are captured and counted based on the video stream, and the mileage basic information is corrected for the third time. The video stream is directly obtained through a visual monitoring camera.

[0010] Furthermore, the fixing features on the outer side of the rail include bolts, fasteners and sleepers.

[0011] Furthermore, the fourth correction of the basic mileage information based on the positioning kilometer mark on the tunnel wall in S5 is specifically as follows: Tunnel inspection cameras collect image data on the tunnel wall, and use image processing and pattern recognition technology to identify and locate kilometer markers.

[0012] Furthermore, if the positioning kilometer marks are dense, the fourth correction is achieved by interpolation; if the positioning kilometer marks are sparse, it is used as a medium- and long-distance correction. Among them, whether the average distance between adjacent positioning kilometer marks is greater than the density threshold is used as the criterion for judging sparseness or density.

[0013] Accordingly, in order to implement the above method, the present invention also provides a mileage positioning system for engineering inspection, comprising: Inspection equipment, which is used to travel on the tunnel route and has a built-in encoder on its wheels for obtaining basic mileage information; a digital inertial navigation module, configured to obtain acceleration data and angular velocity data during the movement of the inspection equipment, obtain displacement information and angular displacement information respectively through integration operations, and perform a first correction on the basic mileage information through interpolation; An inspection camera, the inspection camera is used to photograph the roadbed electronic tag and perform a second correction on the mileage basic information based on the roadbed electronic tag; A visual monitoring camera is used to obtain a video stream containing fixed features on the outer side of the rail, and perform a third correction on the basic mileage information based on the video stream; a tunnel inspection camera, configured to collect image data on the tunnel wall, identify and locate kilometer markers using image processing and pattern recognition technology, and perform a fourth correction on the basic mileage information based on the located kilometer markers; The correction module is used to perform the first correction, the second correction, the third correction and the fourth correction.

[0014] This invention combines data from multiple sensors to perform multiple corrections to basic mileage information, improving the accuracy and reliability of mileage measurement. Compared to traditional positioning methods that rely on sleeper counting, this invention overcomes many drawbacks associated with complex line conditions. It eliminates the need to worry about counting failures due to unusual circumstances or surveillance camera malfunctions, ensuring accurate mileage positioning.

[0015] By combining data from multiple sensors—including wheel encoders, digital inertial navigation modules, inspection cameras, visual monitoring cameras, and tunnel inspection cameras—we can leverage the strengths of each sensor to improve the accuracy and reliability of odometer measurements. The wheel encoders provide basic displacement data, the digital inertial navigation module performs the first correction, the inspection cameras and visual monitoring cameras perform the second and third corrections, and the tunnel inspection camera completes the final precision correction. This fusion of multi-source data results in even more accurate odometer measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a method for mileage positioning in a maintenance inspection according to the present invention; Figure 2 It is a schematic diagram of the composition of a mileage positioning system for engineering inspection according to the present invention. DETAILED DESCRIPTION

[0017] Inspections of civil engineering infrastructure often rely on convenient, automated, and intelligent systems. Furthermore, because rail lines include tunnels, satellite positioning is not feasible. Currently, there are two common ways to install detection modules: one is to install them on the underside of electric trains, operating vehicles, and various types of construction vehicles, enabling immediate inspections as vehicles pass by, thereby improving inspection efficiency on civil engineering lines. The other is to install them on mobile inspection carts to inspect low-speed rail lines. Regardless of the installation method, high-precision alignment of mileage information is essential to ensure the accuracy of the detection alarm results.

[0018] Traditional positioning methods often combine track characteristics with methods such as sleeper counting to perform positioning. However, these methods have significant drawbacks when track conditions are complex. If special circumstances cause the counting process to fail, or if a monitoring camera malfunctions and counting is unsuccessful, the accuracy of mileage positioning cannot be guaranteed.

[0019] In view of this, the present invention provides a method and system for mileage positioning during engineering inspection.

[0020] To make the purpose, technical solutions, and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below with reference to the accompanying drawings. However, it will be understood by those skilled in the art that many technical details are provided in each embodiment of the present application to help readers better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented.

[0021] In the following description, for the purpose of illustrating the various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0022] Unless the context requires otherwise, throughout the specification and claims, the word "comprise" and variations such as "include" and "have" should be construed in an open, inclusive sense, that is, should be interpreted to mean "including, but not limited to."

[0023] The following will describe in detail the various embodiments of the present application in conjunction with the accompanying drawings to provide a clearer understanding of the purpose, features, and advantages of the present application. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present application, but are only intended to illustrate the essential spirit of the technical solution of the present application.

[0024] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0025] Specifically, such as Figure 1 As shown, in one embodiment of the application, the present invention provides a method for mileage positioning of a maintenance inspection, comprising the following steps: S1: Get basic mileage information; S2: Acquire displacement information and angular displacement information to perform a first correction on the basic mileage information; S3: performing a second correction on the basic mileage information based on the roadbed electronic tag; S4: capturing and counting fixed features on the outer side of the rail based on the video stream, and performing a third correction on the basic mileage information; S5: performing a fourth correction on the basic mileage information based on the positioning kilometer mark on the tunnel wall; Wherein, the steps S1 to S5 are performed by the inspection equipment while the vehicle is traveling on the track line.

[0026] By combining data from multiple sensors, the basic mileage information is corrected multiple times to improve the accuracy and reliability of mileage measurement. Compared to the traditional method of using sleeper counting to carry out positioning work, this invention can overcome many disadvantages when the line conditions are more complex. There is no need to worry about special circumstances causing the counting process to fail, or monitoring camera failures causing counting to fail, thus ensuring the accuracy of mileage positioning. Even if a correction cannot be made due to data or other reasons, other corrections can be used to ensure stability, that is, the correction steps are not indispensable.

[0027] Encoder odometry is a method for measuring the distance traveled by mobile objects (such as vehicles and robots) using an encoder. The encoder operates based on the relationship between wheel axle rotation and the distance traveled. By measuring the axle rotation angle or the number of pulses, combined with the wheel circumference, the distance traveled can be calculated.

[0028] Furthermore, in S1, the basic mileage information is obtained based on the encoder: , Where D represents the current inspection distance, N represents the number of pulses output by the encoder per revolution, and C represents the wheel circumference. Wherein, the encoder is located inside the wheel.

[0029] Furthermore, in S2, the displacement information and angular displacement information are obtained based on a digital inertial navigation module to perform a first correction on the mileage basic information: S21: Integrating the acceleration data twice based on the digital inertial navigation module to obtain the displacement information; The specific integration process is: ,in, v ( t ) is the current speed, v0 is the initial velocity, a ( t ) is the acceleration; ,in, s ( t ) is the current location, s 0 is the initial position, v 0 is the initial velocity, a ( t ) is the acceleration; S22: Integrating the angular velocity data based on the digital inertial navigation module to obtain the angular displacement information; The specific integration process is: ,in, θ ( t ) is the current attitude angle, θ 0 is the initial attitude angle, ω ( t ) is the angular velocity.

[0030] S23: interpolating the mileage basic information using the displacement information and the angular displacement information to perform a first correction.

[0031] Among them, considering the diversity and complexity of track lines, the specific interpolation method can be spline interpolation: fitting data points through piecewise polynomials, each piece of the polynomial is defined between two adjacent data points, and maintaining continuity and smoothness at the data points.

[0032] More specifically, by analyzing the error between the interpolated result and the known data points, the interpolation function is adjusted: an error correction term is introduced to bring the interpolated result closer to the true value. Furthermore, for interpolated results that may fluctuate wildly, smoothing algorithms such as moving averages can be used to correct them, making the result smoother and more stable.

[0033] Through interpolation, basic mileage information can be dynamically corrected based on the vehicle's actual motion state, improving the real-time and accuracy of positioning. Furthermore, the introduction of angular displacement information makes this method suitable for positioning on curved tracks, accurately reflecting the vehicle's steering angle and further improving positioning accuracy.

[0034] Furthermore, the acceleration data includes acceleration data in three axes: X, Y, and Z.

[0035] Furthermore, in the second correction of the mileage basic information based on the roadbed electronic tag in S3, the roadbed electronic tag is identified by an inspection camera.

[0036] Typically, RFID tags are installed on the trackbed at regular intervals (100-200 meters) along a subway line. Because these intervals are fixed and relatively accurate, using inspection cameras to capture RFID tags and read basic data from the current beacon allows for mileage corrections at medium and long intervals. This not only further improves mileage positioning accuracy but also reduces mileage error accumulation caused by encoders and digital inertial navigation modules (IMUs).

[0037] The correction may be performed by the interpolation calculation as described above.

[0038] Furthermore, in S4, fixed features on the outer side of the rail are captured and counted based on the video stream, and the mileage basic information is corrected for the third time. The video stream is directly obtained through a visual monitoring camera.

[0039] Video stream data can provide richer line information. Traditionally, single sleeper counts have been used. However, for some complex lines or special sections, sleepers are not always visible and continuous. This is especially true for floating slab trackbeds with no sleepers, making identification nearly impossible. Traditional images capture very limited features. Therefore, direct video stream acquisition is used, and the current count is determined based on the relative position of the features within the field of view. This approach utilizes the Nvidia Jetson platform's DeepStream stream processing engine to implement AI inference within the video stream. This approach effectively addresses complex lines by leveraging fixed features such as bolts and fasteners that appear on the outside of the rails. The identified fastener, bolt, and sleeper areas are tracked, identifying different states of entry and exit from the recognition area, even when stationary. A count of bolts, fasteners, and sleepers is completed once a feature leaves the recognition area.

[0040] Furthermore, the fourth correction of the basic mileage information based on the positioning kilometer mark on the tunnel wall in S5 is specifically as follows: Tunnel inspection cameras collect image data on the tunnel wall, and use image processing and pattern recognition technology to identify and locate kilometer markers.

[0041] Relying on computer vision and deep learning algorithms, image data from tunnel walls is collected and image processing and pattern recognition techniques are used to identify and locate kilometer markers. The specific steps include image acquisition, preprocessing, feature extraction, and recognition and classification. Digital mileage information is directly obtained from the captured images. However, this method of acquiring mileage information needs to be considered in light of the actual route. If mileage markers are densely distributed, interpolation can be used to achieve mileage calibration; if they are sparsely spaced, corrections can be made for medium and long distances. Correction for medium and long distances involves extrapolating sparse data points based on their changing trends. For example, if the known data points exhibit linear or regular variation, a trend line can be fitted to predict the value of the midpoint. The criterion for determining density or sparseness is whether the average distance between adjacent located kilometer markers exceeds a density threshold.

[0042] Accordingly, in order to implement the above method, the present invention proposes a mileage positioning system for engineering inspection, such as Figure 2 Shown, including: Inspection equipment, which is used to travel on the tunnel route and has a built-in encoder on its wheels for obtaining basic mileage information; a digital inertial navigation module, configured to obtain acceleration data and angular velocity data during the movement of the inspection equipment, obtain displacement information and angular displacement information respectively through integration operations, and perform a first correction on the basic mileage information through interpolation; An inspection camera, the inspection camera is used to photograph the roadbed electronic tag and perform a second correction on the mileage basic information based on the roadbed electronic tag; A visual monitoring camera is used to obtain a video stream containing fixed features on the outer side of the rail, and perform a third correction on the basic mileage information based on the video stream; a tunnel inspection camera, configured to collect image data on the tunnel wall, identify and locate kilometer markers using image processing and pattern recognition technology, and perform a fourth correction on the basic mileage information based on the located kilometer markers; The correction module is used to perform the first correction, the second correction, the third correction and the fourth correction according to the above information and data.

[0043] Digital inertial navigation modules, inspection cameras, visual monitoring cameras, tunnel inspection cameras and correction modules are directly installed on the inspection equipment. The inspection equipment can be generally such as inspection robots, inspection carts, etc.

[0044] By combining data from multiple sensors—including wheel encoders, digital inertial navigation modules, inspection cameras, visual monitoring cameras, and tunnel inspection cameras—we can leverage the strengths of each sensor to improve the accuracy and reliability of odometer measurements. The wheel encoders provide basic displacement data, the digital inertial navigation module performs the first correction, the inspection cameras and visual monitoring cameras perform the second and third corrections, and the tunnel inspection camera completes the final precision correction. This fusion of multi-source data results in even more accurate odometer measurements.

[0045] The above is a detailed introduction to a method and system for mileage positioning of civil engineering inspections provided by an embodiment of the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of this application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of this application.

[0046] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0047] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

Claims

1. A method for mileage positioning during a construction inspection, characterized in that: The following steps are involved: S1: Get basic mileage information; S2: Acquire displacement information and angular displacement information to perform a first correction on the basic mileage information; S3: performing a second correction on the basic mileage information based on the roadbed electronic tag; S4: capturing and counting fixed features on the outer side of the rail based on the video stream, and performing a third correction on the basic mileage information; S5: performing a fourth correction on the basic mileage information based on the positioning kilometer mark on the tunnel wall; Wherein, the steps S1 to S5 are performed by the inspection equipment while the vehicle is traveling on the track line.

2. The method for mileage positioning of a construction inspection according to claim 1, characterized in that: In S1, the basic mileage information is obtained based on the encoder: ， Where D represents the current inspection distance, N represents the number of pulses output by the encoder per revolution, and C represents the wheel circumference. Wherein, the encoder is located inside the wheel.

3. The method for mileage positioning of a construction inspection according to claim 1, characterized in that: In S2, the displacement information and angular displacement information are obtained based on the digital inertial navigation module to perform a first correction on the mileage basic information: S21: Integrating the acceleration data twice based on the digital inertial navigation module to obtain the displacement information; S22: Integrating the angular velocity data based on the digital inertial navigation module to obtain the angular displacement information; S23: interpolating the mileage basic information using the displacement information and the angular displacement information to perform a first correction.

4. The method for mileage positioning of a construction inspection according to claim 3, characterized in that: The acceleration data includes acceleration data in three axes: X, Y, and Z.

5. The method for mileage positioning of a construction inspection according to claim 1, characterized in that: In the second correction of the mileage basic information based on the roadbed electronic tag in S3, the roadbed electronic tag is identified by an inspection camera.

6. The method for mileage positioning of a construction inspection according to claim 1, characterized in that: In the S4, fixed features on the outer side of the rail are captured and counted based on the video stream, and the basic mileage information is corrected for the third time. The video stream is directly obtained through a visual monitoring camera.

7. The method for mileage positioning of a construction inspection according to claim 6, characterized in that: The fixing features on the outside of the rail include bolts, fasteners and sleepers.

8. The method for mileage positioning of a construction inspection according to claim 1, characterized in that: The fourth correction of the basic mileage information based on the positioning kilometer mark on the tunnel wall in S5 is specifically as follows: Tunnel inspection cameras collect image data on the tunnel wall, and use image processing and pattern recognition technology to identify and locate kilometer markers.

9. The method for mileage positioning of a construction inspection according to claim 8, characterized in that: If the positioning kilometer marks are dense, the fourth correction is achieved by interpolation; if the positioning kilometer marks are sparse, it is used as a medium- and long-distance correction. Among them, whether the average distance between adjacent positioning kilometer marks is greater than the density threshold is used as the criterion for judging sparseness or density.

10. A mileage positioning system for engineering inspection, characterized in that: include: Inspection equipment, which is used to travel on the tunnel route and has a built-in encoder on its wheels for obtaining basic mileage information; a digital inertial navigation module, configured to obtain acceleration data and angular velocity data during the movement of the inspection equipment, obtain displacement information and angular displacement information respectively through integration operations, and perform a first correction on the basic mileage information through interpolation; An inspection camera, the inspection camera is used to photograph the roadbed electronic tag and perform a second correction on the mileage basic information based on the roadbed electronic tag; A visual monitoring camera is used to obtain a video stream containing fixed features on the outer side of the rail, and perform a third correction on the basic mileage information based on the video stream; a tunnel inspection camera, configured to collect image data on the tunnel wall, identify and locate kilometer markers using image processing and pattern recognition technology, and perform a fourth correction on the basic mileage information based on the located kilometer markers; The correction module is used to perform the first correction, the second correction, the third correction and the fourth correction.

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