CN109085177B

CN109085177B - Leaky cable appearance detection method and device based on RFID positioning

Info

Publication number: CN109085177B
Application number: CN201810960454.1A
Authority: CN
Inventors: 何玉娟; 李斌
Original assignee: Jiaxun Feihong Beijing Intelligent Technology Research Institute Co ltd; China Railway Lanzhou Group Co Ltd
Current assignee: JIAXUN FEIHONG (BEIJING) INTELLIGENT TECHNOLOGY RESEARCH INSTITUTE Co.,Ltd.; China Railway Lanzhou Group Co Ltd
Priority date: 2018-08-22
Filing date: 2018-08-22
Publication date: 2022-03-04
Anticipated expiration: 2038-08-22
Also published as: CN109085177A

Abstract

The invention discloses a leaky cable appearance detection method and device based on RFID positioning. The method comprises the following steps: arranging RFID tags at intervals along the leaky cable, wherein the RFID tags are associated with the position of the leaky cable; the method comprises the following steps that a detection vehicle uses a vehicle-mounted linear array camera to collect leaky cable images along leaky cables when running, and simultaneously scans RFID labels to obtain position information; calculating the vehicle speed according to the obtained position information, and adjusting the scanning line frequency of the linear array camera in real time according to the vehicle speed; and storing the acquired image and the associated information of the corresponding leaky cable position. By using the method, the vehicle-mounted device can provide high-precision positioning information during image acquisition, can obtain the position of a fault during fault detection, and can calculate the vehicle speed during image acquisition, so that the scanning line frequency of a camera is adjusted, and a high-quality image is obtained.

Description

Leaky cable appearance detection method and device based on RFID positioning

Technical Field

The invention relates to a leaky cable appearance detection method, in particular to a leaky cable appearance detection method based on RFID positioning, and also relates to a corresponding leaky cable appearance detection device.

Background

At present, communication leaky coaxial cables are widely adopted in subways and tunnels to achieve wireless coverage, and the leaky coaxial cables are important infrastructure. The leaky cable is usually laid in a wall-hanging mode, and a fixing clamp is installed by drilling a hole in the tunnel wall. The energy wave that the train high-speed travel produced in subway or tunnel is to the vibration and the impact that the leaky cable brought, easily leads to leaky cable corrosion, oxidation and fracture even, leaky cable buckle pine to take off, the leaky cable drips and invades the condition such as limit and take place, seriously threatens driving safety, and to the railway tunnel, abominable natural environment is more obvious to the deformation influence of leaky cable in the tunnel. Maintenance of the leaky cable is therefore particularly important.

At the present stage, appearance faults and hidden dangers of the leaky cable are mainly checked in a manual inspection mode. The manual inspection is low in efficiency and large in workload, is limited by the time for maintaining the skylight in the rail transit, is short in working time, and has great pressure for completing the inspection task. Meanwhile, the manual inspection work is difficult to standardize, is easily influenced by subjective factors and objective environmental factors of operators, and is difficult to find a plurality of potential safety hazards and equipment faults in time.

Aiming at the problems, a vehicle inspection mode can be adopted to replace manual inspection, the appearance image of the leaky cable is acquired through a vehicle-mounted camera, and then fault and hidden danger detection is carried out on the image, so that early warning of the potential safety hazard of the appearance of the leaky cable and fault events is realized.

Therefore, collecting the appearance image of the leaky cable is the primary solution. The quality of the collected images can affect the effect of fault detection, and in addition, the collected images also correspond to the positions of the leaky cables, so that construction and maintenance are facilitated after the faults are detected.

The current position information of the train can be obtained by adopting a common train speed measurement positioning technology, for example: obtaining a position through a GPS signal; obtaining the vehicle speed according to a pulse rotating speed sensor arranged at the axle end of a wheel or a radar speed measuring device arranged at the bottom of the vehicle, and calculating by combining the running time and a reference position to obtain the current position; obtaining a position according to kilometers marks or other information provided by a ground transponder arranged in the middle of the track; or a combination of several techniques.

However, no GPS signal exists in the subway or the tunnel, and direct position information cannot be obtained by using the GPS; the wheel shaft sensor has errors caused by wheel abrasion and idle slip; the radar speed measurement also easily causes integral accumulation errors; the positioning mode based on the transponders has high accuracy, but the distance between each group of transponders is usually more than 1 kilometer, so that the positioning accuracy under the scene of the invention is difficult to ensure.

In chinese patent No. ZL201610365363.4, an appearance detection system and method for a communication leaky cable in a vehicle-mounted tunnel is disclosed, which mainly adjusts the focal length of an image acquisition device in real time according to distance information measured by a laser range finder.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a leaky cable appearance detection method based on RFID positioning.

The invention provides a leaky cable appearance detection device based on RFID positioning.

In order to achieve the purpose, the invention adopts the following technical scheme:

according to a first aspect of the embodiments of the present invention, there is provided a leaky cable appearance detection method based on RFID positioning, including the following steps:

arranging RFID tags at intervals along the leaky cable, wherein the RFID tags are associated with the position of the leaky cable;

the method comprises the following steps that a detection vehicle uses a vehicle-mounted linear array camera to collect leaky cable images along leaky cables when running, and simultaneously scans RFID labels to obtain position information;

calculating the vehicle speed according to the obtained position information, and adjusting the scanning line frequency of the linear array camera in real time according to the vehicle speed;

and storing the acquired image and the associated information of the corresponding leaky cable position.

Preferably, when the RFID tags are arranged along the leaky cable at intervals, the method comprises the following steps:

calculating the minimum set interval of the RFID label according to the maximum speed and the time for the RFID reader to read the RFID label;

obtaining a maximum setting interval according to the requirements of image quality and image position information;

an RFID tag is disposed between the minimum set interval and the maximum set interval.

Preferably, the RFID tag is arranged on the leaky cable, the leaky cable clamp or a tunnel wall along the leaky cable.

Wherein preferably the RFID tag is provided on the breakout clamp closest to the ground.

Preferably, RFID tags are respectively arranged at the entrance and the exit of the tunnel, and when the RFID tags are detected, the vehicle-mounted camera is started or closed to acquire images.

Preferably, the method comprises the following steps of calculating the vehicle speed according to the obtained position information, and adjusting the scanning line frequency of the linear array camera in real time according to the vehicle speed:

calculating the vehicle speed according to the obtained position information of at least two continuous RFID labels;

judging whether the vehicle speed reaches a set frequency modulation limit value; if the frequency does not reach the frequency modulation limit value, the scanning line frequency of the linear array camera is unchanged, otherwise, the scanning line frequency of the linear array camera is adjusted according to the vehicle speed;

wherein, the adjustment adopts the following formula:

f＝kv；

wherein f is the scanning line frequency of the camera, k is the precision coefficient of the camera, and v is the vehicle speed.

Preferably, the leaky cable appearance detection method based on the RFID positioning further comprises the following steps:

carrying out appearance detection processing on the acquired image to obtain fault information; the fault information includes a position or a position interval where the fault is located.

According to a second aspect of the embodiments of the present invention, there is provided a leaky cable appearance detecting apparatus based on RFID positioning, including an RFID tag and an acquisition module;

the acquisition module comprises a control unit, an RFID detection unit, a camera unit and a storage unit;

the RFID detection unit is used for scanning, identifying and reading the RFID tags arranged along the leaky cable and transmitting the scanning result to the control unit;

the camera unit comprises at least one linear array camera;

the control unit receives the RFID tag identification result, calculates the vehicle speed according to the position information corresponding to the RFID tag and the time of scanning the RFID tag, and sends a scanning line frequency adjusting instruction to the camera unit;

the camera unit adjusts the scanning line frequency of the linear array camera according to the scanning line frequency adjusting instruction;

the storage unit is used for storing the acquired images and the associated information of the corresponding leaky cable positions.

Preferably, the leaky cable appearance detection device based on RFID positioning further comprises a detection module; the detection module detects and processes the image to be detected to obtain fault information of the appearance of the leaky cable, wherein the fault information comprises the position or position interval information of the fault.

According to the leaky cable appearance detection method based on RFID positioning, the RFID labels are arranged along the leaky cable, so that on one hand, the leaky cable appearance detection method can be used for providing high-precision positioning information for a vehicle-mounted device during image acquisition, the position of a fault can be obtained during fault detection, and the vehicle speed can be calculated during image acquisition, so that the scanning line frequency of a camera is adjusted, and a high-quality image is obtained; on the other hand, the electronic tag can help maintenance personnel to carry out field positioning by using the auxiliary maintenance terminal and accurately position the fault position.

Drawings

FIG. 1 is a flow chart of a leaky cable appearance detection method based on RFID positioning according to the present invention;

FIG. 2 is a schematic view of a leaky cable installation structure according to an embodiment of the invention;

FIG. 3 is a schematic diagram of the location of an RFID tag in one embodiment of the present invention;

FIG. 4 is a schematic diagram of another location for placement of an RFID tag in an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a leaky cable appearance detecting device based on RFID positioning according to the present invention;

fig. 6 is a schematic structural diagram illustrating a structure of an image timing sequence corresponding to a tag according to an embodiment of the present invention.

Detailed Description

The technical contents of the invention are described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides a method and a device for detecting the appearance of a leaky cable. Firstly, an RFID label is arranged along a leaky cable, and the position of an acquired image is obtained by identifying the RFID label through a vehicle-mounted RFID reader-writer. Regarding the quality of the collected images, besides selecting a proper industrial linear array camera and setting a necessary light supplement source, a proper scanning line frequency is required to be set, so that the scanning line frequency is increased when the vehicle speed is high, the complete images can be scanned, the tensile deformation cannot occur, and when the vehicle speed is low, the compression deformation of the images can be avoided due to the low scanning line frequency. Since the speed of the train is changed during the running process, the scanning line frequency is adjusted according to the change of the speed of the train, so that the optimal image quality can be obtained. In order to obtain the vehicle speed, the vehicle speed can be obtained by calculation by using the positioning method, then the scanning line frequency of the vehicle-mounted camera is adjusted, the image to be detected is subjected to appearance fault detection, and fault information with a fault position or a position section is output to complete the appearance detection.

RFID is a contactless automatic identification technology. The data carrier is an RFID electronic tag, which is referred to as an RFID tag or an electronic tag in the invention for short; the device for reading or writing the RFID label information is called a reader-writer, and the invention has no requirement on writing the label information and only relates to information reading.

For convenience of description, the sections where the subway leaky cable and the railway tunnel leaky cable are laid are collectively called as leaky cable lines, the vehicles carrying the leaky cable image acquisition devices are collectively called as detection vehicles, and the detection vehicles in practical application can be special detection vehicles or operation trains. The appearance faults and the potential safety hazards of the leaky cable are collectively called as appearance faults.

As shown in fig. 1, the leaky cable appearance detecting method based on RFID location provided by the present invention includes the following steps: firstly, arranging RFID tags at intervals along a leaky cable, wherein the RFID tags are associated with the position of the leaky cable; the method comprises the following steps that a detection vehicle uses a vehicle-mounted linear array camera to collect leaky cable images along leaky cables when running, and simultaneously scans RFID labels to obtain position information; then, calculating the vehicle speed according to the obtained position information, and adjusting the scanning line frequency of the linear array camera in real time according to the vehicle speed; finally, storing the collected image and the associated information of the corresponding leaky cable position; in the embodiment provided by the invention, the appearance detection processing is also carried out on the acquired image to obtain the fault information, and the fault information comprises the position or position section of the fault. This process is described in detail below.

And S1, arranging RFID tags at intervals along the leaky cable, wherein the RFID tags are associated with the position of the leaky cable.

According to the invention, the RFID label is arranged along the long-distance communication leaky cable, and the electronic label is a reference label for providing position information, so that on one hand, the RFID label can be used for providing the position information of an image when a vehicle-mounted device collects the image, the position of a fault can be obtained when the fault is detected, and the vehicle speed can be calculated when the image is collected, so that the scanning line frequency of a camera is adjusted, and a high-quality image is obtained; on the other hand, the electronic tag can help maintenance personnel to carry out field positioning by using the auxiliary maintenance terminal and accurately position the fault position.

The RFID tags arranged at intervals along the leaky cable are ultrahigh frequency passive tags and can be arranged on the leaky cable, on a leaky cable clamp or on a tunnel wall along the leaky cable. The RFID tags are distributed at set time intervals, for example: if the RFID tags are arranged on the leaky cables, the RFID tags are distributed on the leaky cables in different types at intervals, and can also be arranged on the leaky cables in the same type at intervals. When the RFID tag is arranged on the leaky cable of the same type, the RFID tag is arranged on the leaky cable closest to the ground, so that maintenance personnel can conveniently scan the RFID tag by using the positioning terminal.

When the RFID label is arranged along the leaky cable, the leaky cable with a long distance is actually divided into a plurality of identifiable short-distance cells. The upper limit of the identifiable cells considers the convenience of maintenance personnel in positioning and the accuracy of positioning and speed measurement of the detection vehicle, and the lower limit of the identifiable cells mainly considers the speed of the vehicle and the identification rate of the tag so as to ensure that the tag can be accurately identified.

The RFID labels are arranged along the leaky cable at intervals, and the method specifically comprises the following steps:

s11, calculating the minimum set interval of the RFID label according to the highest speed and the time for the RFID reader to read the RFID label;

s12, obtaining the maximum setting interval according to the requirement of the definition of the collected image and the requirement of the position information of the collected image;

s13, setting an RFID tag between the minimum set interval and the maximum set interval.

In the embodiment provided by the invention, the time for the RFID reader-writer to read each tag is assumed to be 50ms, when the speed of the train is 160km/h (45m/s), the train runs for 45 meters per second, and the tag interval is set to be more than 2.25 meters within the distance. In the extreme case, the tag spacing should be greater than 5 meters at a vehicle speed of 360km/h (100 m/s). Therefore, the arrangement interval of the RFID tags is feasible within several meters to several tens of meters. After meeting this requirement, a mode of setting at even intervals, for example, one label every 5 meters, or one label every 5 buckles, may be adopted. Or the set intervals at the locations where the tunnel topography changes (such as at tunnel entrances, exits, and curves) are different from the intervals at other locations.

The RFID tag is associated with a leaky cable position; when the RFID tags are set, the corresponding relation between each tag and the position of the leaky cable needs to be recorded, and a corresponding list is formed to facilitate positioning and searching. This list may include the following information: identification number of the tag, spacing from the last tag, distance from the tunnel start, associated location, importance level, etc., are described in detail below.

In the embodiment provided by the invention, RFID tags are arranged at the entrance and the exit of the tunnel, and when the acquisition module detects the RFID tags, the vehicle-mounted camera is started or closed to acquire images.

And S2, acquiring leaky cable images by using a vehicle-mounted linear array camera along the leaky cable when the detection vehicle runs, and scanning the RFID label to obtain position information.

As previously mentioned, in embodiments provided by the present invention, an RFID tag is associated with a drop cable location; when the detection vehicle runs through the leaky cable to collect leaky cable images, the position information can be obtained according to the scanned RFID label.

S3, calculating the vehicle speed according to the obtained position information, and adjusting the scanning line frequency of the linear array camera in real time according to the vehicle speed, wherein the method specifically comprises the following steps:

and S31, calculating the vehicle speed according to the obtained position information of at least two continuous RFID tags.

And obtaining the position information according to the scanned RFID tags, and calculating a vehicle speed according to the position information of at least two front and rear RFID tags, wherein the method for calculating the vehicle speed is an existing conventional method for calculating the vehicle speed or predicting the vehicle speed, and is not described herein again.

S32, judging whether the vehicle speed reaches the set frequency modulation limit value; if the frequency modulation limit value is not reached, the scanning line frequency of the line camera is inconvenient, otherwise, the step S33 is turned to. Wherein the frequency modulation limit value is set according to the characteristics of the linear camera and the quality requirement of the image.

And S33, adjusting the scanning line frequency of the linear array camera according to the vehicle speed. Wherein, the adjustment adopts the following formula:

f＝kv；

where f is the scan line frequency of the camera, k is a coefficient related to the scan accuracy of the camera, the scan accuracy of the camera is related to the number of pixels and the scan width of the camera, and v is the vehicle speed. For example, the vehicle speed is 45m/s, the scanning accuracy of the camera is 1mm, and k is 10³And m, the scanning line frequency is 45 kHz. For example, if it is set that the line frequency of the camera needs to be adjusted when the vehicle speed change exceeds 2m/s (i.e., the frequency modulation limit value is 2m/s), the vehicle speed in the first tag interval is 30m/s, the vehicle speed in the second tag interval is 30.6m/s, the vehicle speed in the third tag interval is 31.2m/s, the vehicle speed in the current tag interval is 31.8 through calculation, and the vehicle speed in the next tag interval is predicted to be 32.4m/s according to the vehicle speed change of the 4 tag intervals and exceeds the frequency modulation limit value, so that the line frequency needs to be adjusted.

And S4, storing the acquired image and the related information of the corresponding leaky cable position.

In the embodiment provided by the invention, after storing the collected image and the associated information of the corresponding leaky cable position, the method further comprises the following steps:

and S5, performing appearance detection processing on the acquired image to obtain fault information, wherein the fault information comprises the position or position section of the fault.

Image acquisition of the leaky cable is the primary solution for detecting appearance faults and potential safety hazards of the leaky cable. The acquired images not only require high quality of clarity and integrity, but also require the ability to provide positional information of the images. This is because, the vehicle-mounted camera is mounted on a train running at high speed, and if the scanning parameters of the camera are improperly set, the acquired image will be distorted by stretching, compressing, etc., which will increase the complexity of image detection; on the other hand, once the potential safety hazard and faults of the leaky cable in the subway section or the railway tunnel which is hundreds of meters or even kilometers long are detected, the position information is provided, so that maintenance personnel can be helped to quickly find the maintenance position on site to carry out maintenance operation.

According to the leaky cable appearance detection method based on RFID positioning, on the premise that the subway and railway transportation order is not influenced, leaky cable images which are high in precision, good in quality and provided with leaky cable position information are acquired in the high-speed running process of a detection vehicle, and appearance fault information is obtained through a flexible appearance detection technology.

The following description will be made in detail by taking the example of collecting a railway tunnel leaky cable. In railway traffic, the tunnel leaky cable comprises a public network leaky cable and a private network leaky cable, which are laid at different heights and are suspended and fixed by using clamps, as shown in fig. 2.

In the embodiment provided by the invention, the vehicle-mounted acquisition module is mounted on the electric service inspection vehicle, and the manual outdoor inspection is replaced by a vehicle inspection operation mode. When the detection vehicle executes a task, image acquisition and fault detection are completed, and the existing transportation order is not influenced.

The following describes specific embodiments of RFID tag setting, RFID detection, and leaky cable appearance image acquisition by a line camera, which are mainly involved in the present invention.

Factors such as vehicle speed, environment, cost, size, installation mode and the like need to be comprehensively considered when selecting the RFID tag. In the embodiment, the limit of the environmental condition of the railway tunnel is considered, the speed of the detection vehicle is about 100km/h, the ultrahigh frequency (870-970 MHz), passive and read-only RFID tag is used, and the detection vehicle has the characteristics of light weight, small volume, low cost, long service life, low environmental requirement, prominent multi-tag identification distance and performance, and the reading distance of the near field of 3.5m also meets the requirement of the application scene of the invention.

The RFID label can be arranged on the leaky cable along the leaky cable in a sticking or packaging mode or on a clamp for fixing the leaky cable. For example, when a new leaky cable is laid, a leaky cable with a built-in RFID label is adopted, or a fixture with a built-in RFID label is adopted; or the RFID label is directly stuck on the leaky cable or the fixture. Of course, it may also be mounted on the tunnel wall, if field conditions permit. Whatever the way the tag is fixed, it is ensured that it is firm and stable.

The location of the RFID tag can be selected as desired. The label can be arranged on one of the leaky cables, for example, the RFID label is arranged on the private network leaky cable, the method has the advantages that the private network leaky cable can be specially monitored, once the label cannot be detected, hidden danger can be preliminarily judged, and early warning can be sent out in time; or can be divided into different groups and arranged on different leaky cables at intervals, as shown in fig. 3, the starting point of adopting the mode is that: when a buckle of a leaky cable at a certain position is loosened, the probability of deformation of the leaky cable at the front and rear positions is higher, so that the probability of loss or displacement of the RFID tags at the positions is higher, the influence on the continuity of the positioning calculation of the vehicle-mounted module can be caused, and the influence can be reduced to a certain extent after the arrangement of the grouping intervals. In the embodiment provided by the invention, considering that the subsequent maintenance personnel need to use the auxiliary positioning maintenance terminal to perform scanning detection on the RFID tag, in order to reduce the antenna power requirement of the RFID detection device of the portable maintenance terminal, it is more beneficial to arrange the RFID tag on a public network leaky cable closest to the ground, as shown in fig. 4.

The RFID labels are arranged along the leaky cable, and the leaky cable with a long distance is actually divided into a plurality of identifiable short-distance cells. The upper limit of the identifiable cells considers the convenience of maintenance personnel in positioning and the accuracy of positioning and speed measurement of the detection vehicle, and the lower limit of the identifiable cells mainly considers the speed of the vehicle and the identification rate of the tag so as to ensure that the tag can be accurately identified. The setting interval is 5 meters in this example.

When the RFID tags are set, the corresponding relation between each RFID tag and the position of the leaky cable needs to be recorded, and a corresponding list is formed to facilitate positioning and searching. This list may include the following information: identification number of the tag, spacing from the last tag, distance from the tunnel start, association location, importance level, etc. As an example of table 1 below, a tag is set at the entrance of the tunnel, and as a starting point, the 2 nd tag is spaced from the starting tag by 5 meters, the 3 rd tag is spaced from the 2 nd tag by 10 meters, and the 4 th tag is also spaced from the 3 rd tag by 10 meters. In practice, the identification number of the RFID tag may be implemented with a longer encoding scheme, which is merely illustrative.

Tag identification number	Label spacer	Distance between two adjacent plates	Associated location	Importance level
					R001	0	0	Inlet port	Of importance
R002	5	5	Special network leaky cable	In general
					R003	10	15	Public network uplink	In general
R004	10	25	Public network downlink	In general

TABLE 1 corresponding relationship table of RFID label and leaky cable position

And the important grade is set for the label, and the fault position which is easy to occur can be subjected to key inspection. The RFID label sets the priority according to the fault occurrence frequency, and the limit RFID label at the position with high fault occurrence frequency is set to be high in level; and the level of the limit RFID label is set to be low at the position with low fault occurrence frequency.

In addition, in order to detect the entrance and exit of the train in and out of the tunnel, specific labels can be arranged at the entrance and exit of the tunnel, and when the labels are scanned by the vehicle-mounted RFID scanner, the specific starting point and the specific ending point of the tunnel can be determined, so that the camera can conveniently turn on and off the acquisition.

In the data content of the RFID tag, the minimum data content is 1bit, which is only used for indicating the existence of the RFID tag, in the embodiment provided by the invention, the 1bit content is difficult to ensure the ideal result, so the data content of the RFID tag at least comprises an identification number representing the identity information of the RFID tag. During detection, the position information of the tag can be obtained by searching the detected RFID identification number in a list recorded during RFID setting, and the vehicle speed is further calculated.

In order to calculate the vehicle speed, at least 2 tags need to be detected, and the distance interval s between two tags and the time interval t between two tags are obtained. Because the distance between the two tags is small, the train can be considered to run at a constant speed in the next tag interval, or the train speed in the next tag interval can be predicted by using a higher-level algorithm. And adjusting the scanning line frequency of the camera when the vehicle speed changes and exceeds a certain limit value. The scan line frequency f of the camera is kv, and k is a coefficient related to the scan accuracy of the camera.

According to the above embodiment, a preferred embodiment of the leaky cable appearance detecting device is as follows:

the ultrahigh frequency passive RFID tags are arranged along the leaky cable at intervals of dozens of meters, a detection vehicle enters a tunnel and detects the RFID tags and collects images of the leaky cable, meanwhile, the scanning line frequency of the vehicle-mounted linear array camera is adjusted according to the vehicle speed, and the collected images have position information and are less in deformation. The appearance detection is realized under the vehicle, when appearance faults or potential safety hazards are detected, fault information is sent to an intelligent terminal of a maintainer, and the maintainer uses an auxiliary maintenance terminal to locate fault points to complete maintenance operation. By adopting the mode, the appearance detection and maintenance efficiency of the leaky cable can be improved.

The invention also provides a leaky cable appearance detection device based on RFID positioning. As shown in fig. 5, the device includes an RFID tag and an acquisition module.

The acquisition module is used for acquiring and storing the content and the image of the RFID label.

The acquisition module comprises a control unit, an RFID detection unit, a camera unit and a storage unit. The RFID detection unit is used for scanning, identifying and reading the RFID tags arranged in the tunnel and transmitting the scanning result to the control unit; the control unit receives the RFID tag identification result, and calculates the vehicle speed according to the position information corresponding to the tag and the time for scanning the RFID tag, so as to send a scanning line frequency adjustment instruction to the camera unit; the camera unit comprises at least one linear array camera, the scanning line frequency of the camera is adjusted according to the scanning line frequency adjusting instruction, and the storage unit is used for storing the acquired images and the associated information of the corresponding leaky cable position.

In the embodiment provided by the invention, the leaky cable appearance detection device based on RFID positioning further comprises a detection module, wherein the detection module is used for detecting and processing the image to be detected to obtain fault information of the leaky cable appearance, and the fault information comprises the position or position interval information of the fault.

In the embodiment provided by the present invention, the camera unit including 2 industrial line cameras and necessary triggering devices and camera fixing devices is taken as an example for explanation. According to the vehicle speed range and the detection precision requirement, a 2k camera is selected. In order to align different leaky cables for image acquisition, the position of the camera needs to be adjusted by selecting a proper height and adjusting an angle. In the embodiment, the acquisition module is carried on the electric service detection vehicle, so that the camera can be fixedly arranged outside the carriage. Because the height difference of the public network leaky cable and the private network leaky cable is 2 meters, and the field range of the camera is limited, the camera for collecting the public network leaky cable is fixed at the 2.1m high position of the vehicle body, and the camera for collecting the private network is fixed at the 3.5m position of the vehicle body. In addition, the acquisition module can be made into a portable device and carried on an operation train, and the angle is adjusted to be aligned to the leaky cable outside the window for acquisition during detection.

The image acquired by adopting the scheme of the invention is provided with the position information of the image, so that firstly, the comparison between the image during the appearance fault detection and the image during the original installation is convenient, and the deformation of the leaky cable is easy to find; and secondly, when the appearance fault or potential safety hazard of the leaky cable is detected, fault information with a fault position is sent to maintenance personnel, so that the positioning of field personnel can be facilitated. And the location information is obtained by detecting the RFID tag. The finally obtained image with the position information has two expression modes, one mode is to obtain the position corresponding to each image, and the other mode is to correspond the image time sequence to the label, as shown in fig. 6. In practice, the latter mode is more economical and practical, and the detected fault can be conveniently located by field maintenance personnel only by locating in a certain label interval.

The control unit of the acquisition module can be realized by selecting an industrial personal computer and a PC (personal computer) or adopting an FPGA (field programmable gate array). The storage unit can select a disk array or an embedded storage scheme, and the embedded storage can be realized by adopting an FPGA. The control unit and the storage unit can be installed in a cabinet in a carriage, and all the acquisition modules can be made into a portable device to be installed and used by detection personnel according to actual conditions.

In order to improve the image acquisition efficiency, the vehicle-mounted RFID reader-writer and the vehicle-mounted RFID camera start to work after the train enters the tunnel and stop working in time after the train exits the tunnel. To achieve this, it is necessary to detect the moment when the train enters and exits the tunnel, and in particular enters a certain tunnel. One method is that firstly, the position information of the GPS is used for judging that a train is about to enter a certain tunnel, RFID scanning is started, and the specific moment of entering the tunnel is determined by scanning an RFID label which is arranged at the entrance of the tunnel in advance, so that camera acquisition is started.

The method and the device for detecting the appearance of the leaky cable based on the RFID positioning provided by the invention are explained in detail above. Any obvious modifications to the invention, which would occur to those skilled in the art, without departing from the true spirit of the invention, would constitute a violation of the patent rights of the invention and would carry a corresponding legal responsibility.

Claims

1. A leaky cable appearance detection method based on RFID positioning is characterized by comprising the following steps:

arranging RFID tags at intervals along the leaky cable, wherein the RFID tags are associated with the position of the leaky cable; the method comprises the following steps that a detection vehicle uses a vehicle-mounted linear array camera to collect leaky cable images along leaky cables when running, and simultaneously scans RFID labels to obtain position information;

storing the collected image and the associated information of the corresponding leaky cable position; wherein the image timing is corresponded to the RFID tag,

the scanning line frequency of the linear array camera is adjusted in real time according to the vehicle speed, and the method comprises the following substeps:

calculating the vehicle speed according to the obtained position information of at least three continuous RFID labels;

wherein, the adjustment adopts the following formula:

f＝kv；

2. The method for detecting the appearance of the leaky cable based on the RFID positioning as claimed in claim 1, wherein when the RFID tags are arranged at intervals along the leaky cable, the method comprises the following steps:

3. The leaky cable appearance detection method based on RFID location as claimed in claim 1, wherein:

the RFID tag is arranged on the leaky cable, the leaky cable clamp or the tunnel wall along the leaky cable.

4. The leaky cable appearance detection method based on RFID location as claimed in claim 3, wherein:

the RFID tag is arranged on the leaky cable clamp nearest to the ground.

5. The leaky cable appearance detection method based on RFID location as claimed in claim 1, wherein:

and respectively arranging RFID tags at the entrance and the exit of the tunnel, and starting or closing the vehicle-mounted camera to acquire images when the RFID tags are detected.

6. The method for detecting the appearance of a leaky cable based on RFID location as claimed in claim 1, further comprising the steps of:

7. A leaky cable appearance detection device based on RFID positioning is characterized by comprising an RFID label and an acquisition module;

the camera unit comprises at least one linear array camera;

the control unit receives the RFID tag identification result, and calculates the vehicle speed according to the position information corresponding to the RFID tag and the time for scanning the RFID tag; sending a scanning line frequency adjusting instruction to the camera unit;

the storage unit is used for storing the acquired images and the associated information corresponding to the cable leakage position; wherein the image timing is associated with the RFID tag.

8. The RFID location-based leaky cable appearance detecting device as claimed in claim 7, further comprising a detecting module;

the detection module detects and processes the image to be detected to obtain fault information of the appearance of the leaky cable, wherein the fault information comprises the position or position interval information of the fault.