Mine conveyor belt offset detection system and method based on RFID

Abstract

The invention discloses a mine conveyor belt deviation detection system and method based on RFID. A deviation detection device comprises a label coupling detection unit and a reader; the label coupling detection unit is arranged at the end of a carrier roller in the conveyor in the length direction. The vertical support is mounted at the top end of the rack; the vertical baffle is installed on the inner side of the vertical support through the telescopic cylinder. The spring is sleeved on the telescopic sleeve; the static RFID tag is mounted on the vertical baffle in an attached manner, and the dynamic RFID tag is mounted on the side end face of the carrier roller in an attached manner; the vertical plate is connected with the vertical support through a transverse connecting rod; a plurality of barbed nails are mounted on the inner side surfaces of the vertical plates; and the reader is arranged on the rack. The method comprises the following steps: installing and debugging the offset detection device; establishing communication connection; in the running process, detection of the deviation state of the belt is achieved through the coupling effect of the dynamic RFID and the static RFID, and an alarm is given when the deviation state occurs. According to the system and the method, low-cost online detection operation of belt deviation can be realized.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent detection technology, and in particular relates to a mine conveyor belt deviation detection system and method based on RFID. Background Art

[0002] Belt conveyors are a common method of transporting materials such as coal and ore from the mining site to their final disposal site. However, during transportation, belts can shift due to various unforeseen factors, such as loose rollers, uneven surfaces, or excessive accumulation of materials. Failure to promptly detect and implement effective emergency measures can lead to serious safety incidents, such as material accumulation, equipment damage, and even casualties.

[0003] In order to timely detect and effectively deal with the deviation of the belt, the current stage mainly relies on frequent manual inspections. This method is not only inefficient, but also has a low safety factor and poses certain safety risks. In recent years, with the rapid development of the Internet of Things and wireless communication technology, RFID technology has been widely used in various fields. Due to the advantages of low cost, wireless sensing, and real-time monitoring, RFID technology has become an effective technical means to solve the problem of belt deviation. In traditional technology, several RFID tags are implanted in the circumference of the belt at set intervals, and then a reader is used to identify and communicate with the RFID tags, thereby realizing the tracking and monitoring process of the belt deviation. However, the application of traditional solutions such as ranging and positioning still has the following disadvantages: (1) It is usually necessary to implant a large number of RFID tags in the belt, and the implementation process is relatively complicated. At the same time, it will significantly reduce the bearing strength of the belt and significantly increase the maintenance cost; (2) The accuracy of deviation detection depends on the layout density of the RFID tags and is also susceptible to environmental interference; (3) The data processing process during deviation identification is relatively complicated and the operating cost is high. These problems limit the effective application of traditional RFID identification technology in conveyor belt deviation detection operations. Therefore, there is an urgent need to provide a more intelligent and low-cost belt deviation monitoring method to ensure the safe and reliable operation of mine conveyors. Summary of the Invention

[0004] To address the problems of the above-mentioned prior art, the present invention provides an RFID-based mine conveyor belt deviation detection system and method. The system has a simple structure, low manufacturing cost, and strong anti-interference capability. It effectively detects the belt deviation status in real time by detecting the presence and disappearance of the coupling effect between static and dynamic RFID tags. It does not require complex calculation processes and has low detection costs. The method has a simple implementation process, low implementation cost, high intelligence, and low computing power requirements. It can monitor and warn of belt deviation in real time and is suitable for various mine transportation systems, especially belt conveyor equipment, and can provide reliable technical support for the safe operation of mine transportation systems.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides a mine conveyor belt deviation detection system based on RFID, including a deviation detection device, an alarm module and a data processing terminal; Two groups of deviation detection devices are respectively located on both sides of the width direction of the conveyor belt, and multiple deviation detection devices in each group are distributed in sequence along the conveying direction; The offset detection device includes a tag coupling detection unit and a reader; the tag coupling detection unit is arranged on the outside of the end of the conveyor roller in the longitudinal direction, and includes a vertical support, a telescopic cylinder, a vertical baffle, a spring, a static RFID tag, a dynamic RFID tag, a vertical plate and a spike; the vertical support is vertically fixedly connected to the top of the conveyor frame; the telescopic cylinder is horizontally arranged on the inner side of the vertical support, and its outer end is fixedly connected to the inner side surface of the vertical support; the outer side surface of the vertical baffle is vertically fixedly connected to the inner end of the telescopic cylinder; the spring sleeve Mounted on the outside of the telescopic cylinder, its two ends are respectively in contact with the vertical baffle and the vertical support; the static RFID tag is fitted on the outer side of the vertical baffle, and the dynamic RFID tag is fitted on the side end surface of the roller; the vertical plate is vertically arranged on the outside of the static RFID tag and fixedly connected to the vertical support via a transverse connecting rod; a plurality of spikes are fixedly mounted in a matrix on the inner side of the vertical plate; the reader is mounted on the conveyor frame and connected to the static RFID tag and the dynamic RFID tag respectively via wireless communication; The alarm module is installed on the conveyor frame; The data processing terminal is connected to the reader, the alarm module and the conveyor respectively.

[0006] Furthermore, in order to achieve stable and reliable telescopic action, and thereby ensure that when deviation occurs, the static RFID tag can be driven to move toward the direction of the nail through timely retraction action to achieve timely damage to the static RFID tag, the telescopic cylinder includes an inner cylinder, an outer cylinder, an outer limit ring and an inner limit ring, the outer cylinder is axially slidable on the outside of the inner cylinder, the outer limit ring and the inner limit ring are arranged at intervals on the left and right sides between the inner cylinder and the outer cylinder, and the outer limit ring is fixedly mounted on the outer side of the inner end of the inner cylinder, and the inner limit ring is fixedly mounted on the inner side of the inner end of the outer cylinder, and cooperates with the outer limit ring to limit the position.

[0007] As a preference, the data processing terminal is an industrial computer.

[0008] Furthermore, in order to improve the warning effect and to more effectively remind relevant personnel to take effective emergency treatment measures in a timely manner, the alarm module is an alarm with sound, light and voice broadcast functions.

[0009] In the present invention, a vertical support is fixedly connected to the top of the conveyor frame, and a vertical baffle is connected to the inner side of the vertical support via a transversely arranged telescopic sleeve. This allows the vertical baffle to move laterally along the width of the belt. A spring is mounted on the exterior of the telescopic sleeve, and the spring's elastic force reliably supports the telescopic sleeve in its normal state, ensuring that the telescopic sleeve is at its maximum extension. A static RFID tag is mounted on the inner side of the vertical baffle, and the telescopic sleeve in its maximum extension state maintains the stability of the static RFID tag's position. Several spikes are fixedly mounted on the outer side of the vertical baffle using the vertical plate, corresponding to the position of the static RFID tag. This eliminates the need for strong friction, and only requires high pressure to immediately damage the static RFID tag. When the belt is deflected or squeezed, the vertical baffle can promptly move into contact with the vertical plate, ensuring that the spikes immediately damage the static RFID tag, ensuring timely and reliable detection. By fitting the dynamic RFID tag onto the side surface of the roller, it can rotate slightly with the roller. Once the reader is mounted on the frame, the coupling effect between the dynamic and static RFID tags can be used to effectively detect belt deviation. When the belt is operating normally, the belt does not deviate outward and press against the vertical baffle. The coupling effect between the static and dynamic RFID tags persists. At this point, the reader can simultaneously read the RSSI signals of both the static and dynamic RFI tags, with the RSSI values remaining within a large fluctuation range B. When the static RFID tag is pressed against the spikes by the deflected belt until it aligns with the spikes, the spikes immediately damage the static RFID tag, eliminating the coupling between the static and dynamic tags. The reader can then read only the RSSI signal of the static RFID tag, with the RSSI value remaining within a small fluctuation range A. At this point, the reader can directly send a belt deviation warning signal to the data processing terminal, which can then take effective emergency measures based on the received belt deviation warning signal. The system's vertical supports, telescopic sleeves, springs, vertical plates, and spikes are connected in an integrated design, resulting in a simpler and more compact structure, easier installation, and higher stability and reliability. Compared to traditional belt deviation detection structures, this system is less susceptible to environmental interference and offers lower installation costs, significantly improving detection convenience and reducing costs.

[0010] The system has a simple structure, low manufacturing cost and strong anti-interference ability. It can effectively detect the belt deviation status in real time through the existence and disappearance of the coupling effect between static RFID tags and dynamic RFID tags. It does not require complex calculation processes and has low detection costs. At the same time, the use of this system does not require the embedding of a large number of RFID tags in the belt, which can effectively ensure the bearing strength of the belt and effectively reduce the maintenance costs of the belt and massive RFID tags.

[0011] The present invention also provides a mine conveyor belt deviation detection method based on RFID, which uses a mine conveyor belt deviation detection system based on RFID, including the following steps: Step 1: Install and debug the offset detection device; S11: First, the dynamic RFID tag is mounted on the side surface of the roller. Then, based on the Fresnel zone theory, the distance and position of the reader relative to the dynamic RFID tag are determined. The reader is then mounted on the conveyor frame. Then, the conveyor is started and the detection time is set. When the belt is running normally, the RSSI fingerprint information and the RSSI small fluctuation range A of the dynamic RFID tag are read using the reader. S12: First, determine the distance and position of the static RFID tag relative to the dynamic RFID tag based on the Fresnel zone theory. Then, based on the determined position of the static RFID tag, vertically install the vertical support on the top of the conveyor frame and ensure that the vertical baffle is located outside the edge of the belt. Then, restart the conveyor and set the detection time. When the belt is operating normally and there is a coupling effect between the static RFID tag and the dynamic RFID tag, use the reader to read the RSSI fingerprint information and the maximum fluctuation range B of the RSSI value of the static RFID tag and the dynamic RFID tag. S13: In the manner of S11 and S12, a plurality of offset detection devices are arranged on both sides of the width direction of the belt in the conveyor, and each Step 2: Establish a communication connection; Establishing communication connections between the data processing terminal, the alarm module, the transporter and the plurality of readers; Step 3: Online offset detection operation; During conveyor operation, a reader performs real-time RSSI readings. Combined with multiple deviation detection devices, the reader detects deviation in different sections of the belt. When the belt is operating normally, the belt edge is not in contact with the tag coupling detection unit in the deviation detection device. The reader can simultaneously read the RSSI fingerprint information of both static and dynamic RFID tags, and the RSSI values read are within the large fluctuation range B. At this point, the reader is inactive. If the belt in any monitoring section deviates, the deviated belt squeezes and pushes the vertical baffle into close contact with it. The destructive action of the spikes directly damages the static RFID tag, eliminating the coupling effect between the static and dynamic RFID tags. The reader can only read the RSSI fingerprint information of the dynamic RFID tag, and the RSSI values read are within the small fluctuation range A. At this point, the reader in the corresponding monitoring section sends a deviation warning signal to the data processing terminal. Upon receiving the deviation warning signal for the corresponding monitoring section, the data processing terminal controls the alarm device to sound an alarm.

[0012] Furthermore, to ensure the accuracy and timeliness of detection, in step 1 S12, the process of determining the distance and position between the static RFID tag and the dynamic RFID tag based on the Fresnel zone theory is as follows: S12-1: For a given radio wavelength , construct a Fresnel zone containing n ellipses according to formula (1); Where, Indicates a reader / writer; Indicates an RFID tag; is a point on the nth ellipse; S12-2: Obtain the boundary point set of the nth Fresnel zone according to formula (2); S12-3: Set the reader at a position within the 8th to 12th zone from the dynamic RFID tag according to formula (2), and ensure that after the static RFID tag is installed, the signal path length difference between the static RFID tag and the dynamic RFID tag is .

[0013] As a preferred embodiment, in step three, the RSSI value read by the reader is obtained according to formula (3); Where, is the distance between the transmitting signal and the receiving signal, For environmental factors.

[0014] Furthermore, in order to improve the alarm reminder effect, in step three, the alarm device simultaneously performs buzzer alarm, flash alarm and preset voice broadcast alarm actions when alarming.

[0015] Furthermore, in order to achieve timely shutdown under abnormal working conditions and avoid unexpected accidents, in step three, when the reader cannot read the RSSI fingerprint information of the static RFID tag and the dynamic RFID tag, an emergency stop signal is sent to the data processing terminal. After receiving the emergency stop signal, the data processing terminal controls the conveyor to stop.

[0016] The present invention provides an RFID-based method for detecting belt deviation in a mine conveyor. The method utilizes RFID (Radio Frequency Identification) technology and cleverly combines the coupling effect between dynamic and static RFID tags to achieve real-time, reliable monitoring and early warning of belt deviation in a low-cost manner. The dynamic RFID tag is vertically and tightly mounted on the side end face of the roller, while the static RFID tag is vertically and tightly mounted on the vertical baffle. This ensures that the phase difference between the dynamic and static RFID tags is approximately constant, and the distance between them fluctuates minimally, ensuring maximum signal strength received by the reader and effectively ensuring detection accuracy. The coupling effect between the dynamic and static tags allows for real-time monitoring of belt deviation. Once the belt deviates, the static RFID tag is destroyed, eliminating the coupling effect between the dynamic and static RFID tags. This promptly triggers the deviation alarm mechanism, providing timely and reliable early warning signals to miners in the underground working area and effectively preventing unexpected accidents. During the detection process, the system cleverly utilizes signal amplification technology based on Fresnel zone theory to set the distance between the dynamic and static RFID tags, effectively amplifying the received signal strength (RSSI) using the Fresnel zone effect. Compared to traditional methods, this approach more accurately captures RSSI value changes caused by coupling failure, improving signal perception accuracy and stability, and further ensuring the accuracy of offset detection. By pre-collecting RSSI fingerprint information under normal operating conditions, the RSSI value read in real time can be effectively compared with the RSSI fingerprint information read in advance during the detection process. This not only effectively adapts to different environmental interference conditions but also facilitates the timely implementation of effective early warning measures when abnormal situations occur, further improving the detection capacity and response capabilities of abnormal conditions.

[0017] This method has a simple implementation process, low implementation cost, high intelligence, and low computing power requirement. It can monitor and warn of belt deviation in real time. It is suitable for various mine transportation systems, especially belt transportation equipment, and can provide reliable technical support for the safe operation of mine transportation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic diagram of the assembly of the deviation detection device of the present invention on a conveyor; Figure 2 It is a structural schematic diagram of the offset detection device in the present invention; Figure 3 yes Figure 2 A partial enlarged view of the Figure 4 It is a structural schematic diagram of the telescopic sleeve in the present invention; Figure 5 It is a principle block diagram of the control part in the present invention.

[0019] Figure 6 It is a schematic flow chart of the detection method of the present invention; Figure 7 It is a schematic diagram of the principle of amplifying signal strength of the present invention; Figure 8 This is a schematic diagram of the principle of applying the Fresnel zone in the present invention; Figure 9 Schematic diagram of RSSI values with and without coupling effect according to the present invention.

[0020] In the figure: 1. Vertical support, 2. Inner cylinder, 3. Outer cylinder, 4. Vertical baffle, 5. Spring, 6. Static RFID tag, 7. Dynamic RFID tag, 8. Vertical plate, 9. Spike, 10. Transverse connecting rod, 11. Conveyor frame, 12. Offset detection device, 13. Reader, 14. Belt, 15. Roller, 16. Telescopic cylinder, 17. Outer limit ring, 18. Inner limit ring, 19. Tag coupling detection unit. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] like Figures 1 to 5 As shown, the present invention provides a mine conveyor belt deviation detection system based on RFID, including a deviation detection device 12, an alarm module and a data processing terminal; Two groups of deviation detection devices 12 are respectively located on both sides of the width direction of the conveyor belt 14, and the multiple deviation detection devices 12 in each group are distributed in sequence along the conveying direction; The deviation detection device 12 includes a tag coupling detection unit 19 and a reader 13; the tag coupling detection unit 19 is arranged on the outside of the longitudinal end of the conveyor roller 15, and includes a vertical support 1, a telescopic cylinder 16, a vertical baffle 4, a spring 5, a static RFID tag 6, a dynamic RFID tag 7, a vertical plate 8 and a spike 9; the vertical support 1 is vertically fixedly connected to the top of the conveyor frame 11; the telescopic cylinder 16 is horizontally arranged on the inner side of the vertical support 1, and its outer end is fixedly connected to the inner side surface of the vertical support 1; the outer side surface of the vertical baffle 4 is vertically fixedly connected to the inner end of the telescopic cylinder 16; the The spring 5 is sleeved on the outside of the telescopic cylinder 16, with its two ends respectively abutting the vertical baffle 4 and the vertical support 1; the static RFID tag 6 is snugly mounted on the outer surface of the vertical baffle 4, and the dynamic RFID tag 7 is snugly mounted on the side end surface of the roller 15; the vertical plate 8 is vertically arranged on the outside of the static RFID tag 6 and fixedly connected to the vertical support 1 via a transverse connecting rod 10; a plurality of spikes 9 are fixedly mounted in a matrix on the inner side of the vertical plate 8; the reader 13 is mounted on the conveyor frame 11 and is connected to the static RFID tag 6 and the dynamic RFID tag 7 respectively via wireless communication; The alarm module is installed on the transport machine frame 11; The data processing terminal is connected to the reader 13, the alarm module and the conveyor respectively.

[0023] The telescopic cylinder 16 includes an inner cylinder 2, an outer cylinder 3, an outer limit ring 17 and an inner limit ring 18. The outer cylinder 3 is axially slidably mounted on the outside of the inner cylinder 2. The outer limit ring 17 and the inner limit ring 18 are spaced apart on the left and right sides of the part between the inner cylinder 2 and the outer cylinder 3. The outer limit ring 17 is fixedly mounted on the outer side of the inner end of the inner cylinder 2, and the inner limit ring 18 is fixedly mounted on the inner side of the inner end of the outer cylinder 3, and is limitedly matched with the outer limit ring 17.

[0024] Among them, under the normal action of the spring 5, the telescopic cylinder 16 is maintained in the maximum extension state. At this time, the vertical baffle 4 is located at a set distance outside the end of the length direction of the roller 15, which does not affect the belt 14 in the normal operating state. When the belt 14 deviates to one side, the belt 4 deviated to the outside will push the vertical baffle 4 to move outward, and then overcome the elastic force of the spring 5 to move the static RFID tag 6 to the position close to the thorn nail 9. When the deflection state reaches the critical detection state, under the squeezing action of the belt 4, the static RFID tag 6 is tightly fitted with the thorn nail 9. Under the destructive action of the thorn nail 9, the static RFID tag 6 is When the static RFID tag 6 is damaged, the coupling between the static RFID tag 6 and the dynamic RFID tag 7 disappears, and the reader 13 can only detect the RSSI signal of the dynamic RFID tag 7. At the same time, the RSSI read is within the small fluctuation range A. At this time, the reader 13 directly sends a deviation warning signal to the data processing terminal. After receiving the deviation warning signal, the data processing terminal directly determines that the belt 14 is deviated and controls the alarm module to sound and light alarms. At the same time, the conveyor can be directly stopped according to the number of deviation warning signals received from the reader 13. As a preference, the data processing terminal is an industrial computer.

[0025] In order to improve the warning effect and to more effectively remind relevant personnel to take effective emergency treatment measures in a timely manner, the alarm module is an alarm with sound, light and voice broadcast functions.

[0026] In the present invention, a vertical support is fixedly connected to the top of the conveyor frame, and a vertical baffle is connected to the inner side of the vertical support via a transversely arranged telescopic sleeve. This allows the vertical baffle to move laterally along the width of the belt. A spring is mounted on the exterior of the telescopic sleeve, and the spring's elastic force reliably supports the telescopic sleeve in its normal state, ensuring that the telescopic sleeve is at its maximum extension. A static RFID tag is mounted on the inner side of the vertical baffle, and the telescopic sleeve in its maximum extension state maintains the stability of the static RFID tag's position. Several spikes are fixedly mounted on the outer side of the vertical baffle using the vertical plate, corresponding to the position of the static RFID tag. This eliminates the need for strong friction, and only requires high pressure to immediately damage the static RFID tag. When the belt is deflected or squeezed, the vertical baffle can promptly move into contact with the vertical plate, ensuring that the spikes immediately damage the static RFID tag, ensuring timely and reliable detection. By fitting the dynamic RFID tag onto the side surface of the roller, it can rotate slightly with the roller. Once the reader is mounted on the frame, the coupling effect between the dynamic and static RFID tags can be used to effectively detect belt deviation. When the belt is operating normally, the belt does not deviate outward and press against the vertical baffle. The coupling effect between the static and dynamic RFID tags persists. At this point, the reader can simultaneously read the RSSI signals of both the static and dynamic RFI tags, with the RSSI values remaining within a large fluctuation range B. When the static RFID tag is pressed against the spikes by the deflected belt until it aligns with the spikes, the spikes immediately damage the static RFID tag, eliminating the coupling between the static and dynamic tags. The reader can then read only the RSSI signal of the static RFID tag, with the RSSI value remaining within a small fluctuation range A. At this point, the reader can directly send a belt deviation warning signal to the data processing terminal, which can then take effective emergency measures based on the received belt deviation warning signal. The system's vertical supports, telescopic sleeves, springs, vertical plates, and spikes are connected in an integrated design, resulting in a simpler and more compact structure, easier installation, and higher stability and reliability. Compared to traditional belt deviation detection structures, this system is less susceptible to environmental interference and offers lower installation costs, significantly improving detection convenience and reducing costs.

[0027] The system has a simple structure, low manufacturing cost and strong anti-interference ability. It can effectively detect the belt deviation status in real time through the existence and disappearance of the coupling effect between static RFID tags and dynamic RFID tags. It does not require complex calculation processes and has low detection costs. At the same time, the use of this system does not require the embedding of a large number of RFID tags in the belt, which can effectively ensure the bearing strength of the belt and effectively reduce the maintenance costs of the belt and massive RFID tags.

[0028] like Figure 6 As shown, the present invention provides a mine conveyor belt deviation detection method based on RFID, using a mine conveyor belt deviation detection system based on RFID, including the following steps: Step 1: Install and debug the offset detection device 12; S11: First, the dynamic RFID tag 7 is tightly mounted on the side surface of the roller 15. Then, based on the Fresnel zone theory, the distance and position of the reader 13 relative to the dynamic RFID tag 7 are determined. The reader 13 is then mounted on the conveyor frame 11. Then, the conveyor is started and a detection time is set. With the belt 14 operating normally, the RSSI fingerprint information and the RSSI small fluctuation range A of the dynamic RFID tag 7 are read using the reader 13. S12: First, based on the Fresnel zone theory, the distance and position of the static RFID tag 6 relative to the dynamic RFID tag 7 are determined. Then, based on the determined position of the static RFID tag 6, the vertical support 1 is vertically installed on the top of the conveyor frame 11, and the vertical baffle 4 is ensured to be located outside the edge of the belt 14. Then, the conveyor is restarted and the detection time is set. When the belt 14 is operating normally and there is a coupling effect between the static RFID tag 6 and the dynamic RFID tag 7, the RSSI fingerprint information and the large fluctuation range B of the RSSI value of the static RFID tag 6 and the dynamic RFID tag 7 are read using the reader 13; S13: In the manner of S11 and S12, a plurality of deviation detection devices 12 are respectively arranged on both sides of the width direction of the belt 14 in the conveyor, and each Step 2: Establish a communication connection; Establishing communication connections between the data processing terminal, the alarm module, the transporter and the plurality of readers 13; Step 3: Online offset detection operation; During the operation of the conveyor, the reader 13 is used to perform real-time reading of the RSSI value, and in combination with multiple offset detection devices 12, real-time detection is performed to detect whether different sections of the belt 14 are offset. When the belt 14 is in normal operation, the edge of the belt 14 is not in contact with the tag coupling detection unit 19 in the offset detection device 12. The reader 13 can simultaneously read the RSSI fingerprint information of the static RFID tag 6 and the dynamic RFID tag 7, and the RSSI value read is within the large fluctuation range B. At this time, the reader 13 does not operate. When the belt 14 in any monitoring section deviates When the offset belt 14 squeezes and pushes the vertical baffle 4 to a state of close contact with the vertical plate 8, the static RFID tag 6 is directly damaged by the destructive action of the spike 9, and the coupling effect between the static RFID tag 6 and the dynamic RFID tag 7 disappears. The reader 13 can only read the RSSI fingerprint information of the dynamic RFID tag 7, and the read RSSI value is within a small fluctuation range A. At this time, the reader 13 of the corresponding monitoring section sends an offset warning signal to the data processing terminal. After receiving the offset warning signal of the corresponding monitoring section, the data processing terminal controls the alarm device to sound an alarm to notify the relevant operator or system monitoring center.

[0029] like Figure 9 As shown, when there is a coupling effect between two tags, The RSSI of the static RFID tag swings around and converges to (Dynamic RFID tags) Value when not in the read zone, when there is no coupling effect between the two tags, The fluctuation range of (dynamic RFID tags) is significantly reduced.

[0030] To ensure the accuracy and timeliness of detection, in step 1 S12, the process of determining the distance and position between the static RFID tag 6 and the dynamic RFID tag 7 based on the Fresnel zone theory is as follows: S12-1: For a given radio wavelength , construct a Fresnel zone containing n ellipses according to formula (1); Where, Represents a reader / writer 13; Indicates an RFID tag; is a point on the nth ellipse; Fresnel zones are concentric ellipses with focusing in a pair of transceivers, e.g. Figure 8As shown, the innermost ellipse is defined as the first Fresnel zone, the elliptical annulus between the first and second ellipses is defined as the second Fresnel zone, and the nth Fresnel zone corresponds to the elliptical annulus between the (n−1)th and nth ellipses.

[0031] S12-2: Since the boundary between two adjacent Fresnel zones is an ellipse, the boundary of the nth Fresnel zone is defined as the ellipse between the nth and (n+1)th Fresnel zones. Specifically, the boundary point set of the nth Fresnel zone is obtained according to formula (2); S12-3: Obviously, as n changes from 1 to n, the width of the Fresnel zone decreases continuously, approaching The important area for RF transmission is the first 8 to 12 zones. More than 70% of the energy is transmitted through the first Fresnel zone. Therefore, the distance between the reader and the RFID tag should be controlled within the 8 to 12 zones as much as possible. Specifically, according to formula (2), the reader 13 is set at a position within the 8th to 12th zones from the dynamic RFID tag 7; when Through line-of-sight (LOS) propagation When a radio signal is transmitted, the amplitude and phase shift of the received signal are determined by To achieve a phase difference of 0°, it is necessary to ensure that after the static RFID tag 6 is installed, the signal path length difference between the static RFID tag 6 and the dynamic RFID tag 7 is .

[0032] The RSSI calculation formula is usually composed of receiving sensitivity S and transmitting signal strength P, and its formula is: In order to more accurately represent the RSSI value and thus achieve more accurate detection, in step three, the RSSI value read by the reader 13 is obtained according to formula (3); Where, is the distance between the transmitting signal and the receiving signal, For environmental factors.

[0033] In order to improve the alarm reminder effect, in step three, the alarm device simultaneously performs buzzer alarm, flash alarm and preset voice broadcast alarm actions when alarming.

[0034] In order to achieve timely shutdown under abnormal working conditions and avoid unexpected accidents, in step three, when the reader 13 cannot read the RSSI fingerprint information of the static RFID tag 6 and the dynamic RFID tag 7, an emergency stop signal is sent to the data processing terminal. After receiving the emergency stop signal, the data processing terminal controls the conveyor to stop.

[0035] As a further preference, when belt deviation occurs and an early warning is issued, the data processing terminal can also record and analyze historical alarm data to provide important technical reference for future system optimization and improvement.

[0036] Working principle: The reader 13 transmits a radio frequency signal and receives a response signal from the RFID tag at the same time. The received response signal consists of a dynamic vector and a static vector. The dynamic vector rotates around the static vector. When the phase difference between the dynamic vector and the static vector is 0°, the received signal strength is the largest, as shown in the following example. Figure 7 As shown, a dynamic RFID tag 7 is vertically and tightly mounted on the side surface of the roller 5. This ensures that the phase difference between the dynamic and static RFID tags is approximately constant, ensuring that the signal strength received by the reader 13 is maximized. When the reader 13 receives the response signal, it first filters out interference signals from the environment, synchronizes the clock, and then uses signal processing methods to amplify the signal changes. Under normal circumstances, coupling occurs between the static and dynamic RFID tags. Since the distance between the dynamic and static RFID tags varies relatively little, the rotation speed of the roller 5 is relatively constant, and the surrounding environment of the roller 5 does not change significantly, the RSSI value should fluctuate within a certain large fluctuation range B, and the fluctuation should have a certain periodicity and regularity. Once the belt 14 deviates, the spikes 9 will immediately damage the static RFID tag 6, causing the coupling effect to disappear. The RSSI value will fluctuate within a small fluctuation range A. When the coupling effect disappears, a deviation warning signal can be immediately issued, effectively warning of belt deviation.

[0037] This method has a simple implementation process, low implementation cost, high intelligence, and low computing power requirement. It can monitor and warn of belt deviation in real time. It is suitable for various mine transportation systems, especially belt transportation equipment, and can provide reliable technical support for the safe operation of mine transportation systems.

Claims

1. A mine conveyor belt deviation detection system based on RFID, comprising a deviation detection device (12), characterized in that: It also includes an alarm module and a data processing terminal; Two groups of deviation detection devices (12) are respectively located on both sides of the width direction of the belt (14) in the conveyor, and the plurality of deviation detection devices (12) in each group are sequentially spaced and distributed along the conveying direction; The offset detection device (12) includes a tag coupling detection unit (19) and a reader (13); the tag coupling detection unit (19) is arranged on the outside of the longitudinal end of the conveyor roller (15), and includes a vertical support (1), a telescopic cylinder (16), a vertical baffle (4), a spring (5), a static RFID tag (6), a dynamic RFID tag (7), a vertical plate (8) and a spike (9); the vertical support (1) is vertically fixedly connected to the top of the conveyor frame (11); the telescopic cylinder (16) is horizontally arranged on the inside of the vertical support (1), and its outer end is fixedly connected to the inner side surface of the vertical support (1); the outer side surface of the vertical baffle (4) is vertically fixedly connected to the inner end of the telescopic cylinder (16); The spring (5) is sleeved on the outside of the telescopic cylinder (16), and its two ends are respectively in contact with the vertical baffle (4) and the vertical support (1); the static RFID tag (6) is fitted on the outer side of the vertical baffle (4), and the dynamic RFID tag (7) is fitted on the side end surface of the roller (15); the vertical plate (8) is vertically arranged on the outside of the static RFID tag (6) and is fixedly connected to the vertical support (1) through a transverse connecting rod (10); a plurality of spikes (9) are fixedly installed in a matrix on the inner side of the vertical plate (8); the reader (13) is installed on the conveyor frame (11) and is respectively connected to the static RFID tag (6) and the dynamic RFID tag (7) through wireless communication; The alarm module is mounted on a conveyor frame (11); The data processing terminal is connected to the reader (13), the alarm module and the conveyor respectively.

2. The RFID-based mine conveyor belt deviation detection device according to claim 1, characterized in that: The telescopic cylinder (16) comprises an inner cylinder (2), an outer cylinder (3), an outer limiting ring (17) and an inner limiting ring (18); the outer cylinder (3) is axially slidably mounted on the outside of the inner cylinder (2); the outer limiting ring (17) and the inner limiting ring (18) are arranged at intervals between the inner cylinder (2) and the outer cylinder (3); the outer limiting ring (17) is fixedly mounted on the outer side of the inner end of the inner cylinder (2); the inner limiting ring (18) is fixedly mounted on the inner side of the inner end of the outer cylinder (3) and is limitedly matched with the outer limiting ring (17).

3. The RFID-based mine conveyor belt deviation detection device according to claim 1, characterized in that: The data processing terminal is an industrial computer.

4. The RFID-based mine conveyor belt deviation detection device according to claim 1, characterized in that: The alarm module is an alarm with sound, light and voice broadcast functions.

5. A mine conveyor belt deviation detection method based on RFID, using a mine conveyor belt deviation detection system based on RFID as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Install and debug the offset detection device (12); S11: First, the dynamic RFID tag (7) is mounted on the side end surface of the roller (15) in a close-fitting manner. Then, based on the Fresnel zone theory, the distance and position of the reader (13) relative to the dynamic RFID tag (7) are determined. The reader (13) is mounted on the conveyor frame (11). Then, the conveyor is started and the detection time is set. When the belt (14) is in normal operation, the RSSI fingerprint information and the small fluctuation range A of the RSSI of the dynamic RFID tag (7) are read by the reader (13). S12: First, based on the Fresnel zone theory, the distance and position between the static RFID tag (6) and the dynamic RFID tag (7) are determined. Then, based on the position of the static RFID tag (6), the vertical support (1) is vertically installed on the top of the conveyor frame (11), and it is ensured that the vertical baffle (4) is located outside the edge of the belt (14). Then, the conveyor is restarted to set the detection time. When the belt (14) is running normally and there is a coupling effect between the static RFID tag (6) and the dynamic RFID tag (7), the RSSI fingerprint information of the static RFID tag (6) and the dynamic RFID tag (7) and the large fluctuation range B of the RSSI value are read by the reader (13); S13: In the manner of S11 and S12, a plurality of offset detection devices (12) are respectively arranged on both sides of the width direction of the belt (14) in the conveyor, and each Step 2: Establish a communication connection; establishing communication connections between the data processing terminal, the alarm module, the transporter, and the plurality of readers (13); Step 3: Online offset detection operation; During the operation of the conveyor, the reader (13) is used to read the RSSI value in real time, and in combination with multiple offset detection devices (12), different sections of the belt (14) are detected in real time to see if there is any offset. When the belt (14) is in normal operation, the edge of the belt (14) is not in contact with the tag coupling detection unit (19) in the offset detection device (12). The reader (13) can simultaneously read the RSSI fingerprint information of the static RFID tag (6) and the dynamic RFID tag (7), and the RSSI value read is within a large fluctuation range B. At this time, the reader (13) does not operate. When the belt (14) in any monitoring section is ) when the offset occurs, the offset belt (14) squeezes and pushes the vertical baffle (4) to a state of close contact with the vertical plate (8). Under the destructive action of the spikes (9), the static RFID tag (6) is directly damaged, and the coupling effect between the static RFID tag (6) and the dynamic RFID tag (7) disappears. The reader (13) can only read the RSSI fingerprint information of the dynamic RFID tag (7), and the read RSSI value is within the small fluctuation range A. At this time, the reader (13) of the corresponding monitoring section sends a deviation warning signal to the data processing terminal. After receiving the deviation warning signal of the corresponding monitoring section, the data processing terminal controls the alarm device to sound an alarm.

6. The RFID-based mine conveyor belt deviation detection method according to claim 5, characterized in that: In step 1 S12, the process of determining the distance and position between the static RFID tag (6) and the dynamic RFID tag (7) based on the Fresnel zone theory is as follows: S12-1: For a given radio wavelength , construct a Fresnel zone containing n ellipses according to formula (1); （1）； Where, Represents a reader / writer (13); Indicates an RFID tag; is a point on the nth ellipse; S12-2: Obtain the boundary point set of the nth Fresnel zone according to formula (2); S12-3: According to formula (2), the reader (13) is set at a position within the 8th to 12th zone from the dynamic RFID tag (7), and it is ensured that after the static RFID tag (6) is installed, the signal path length difference between the static RFID tag (6) and the dynamic RFID tag (7) is .

7. The RFID-based mine conveyor belt deviation detection method according to claim 6, characterized in that: In step 3, the RSSI value read by the reader (13) is obtained according to formula (3); （3）； Where, is the distance between the transmitting signal and the receiving signal, For environmental factors.

8. The RFID-based mine conveyor belt deviation detection method according to claim 7, characterized in that: In step three, when the alarm device sounds an alarm, it simultaneously performs buzzer alarm, flash alarm and preset voice broadcast alarm actions.

9. The RFID-based mine conveyor belt deviation detection method according to claim 8, characterized in that: In step three, when the reader (13) cannot read the RSSI fingerprint information of the static RFID tag (6) and the dynamic RFID tag (7), an emergency stop signal is sent to the data processing terminal. After receiving the emergency stop signal, the data processing terminal controls the conveyor to stop.

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