Belt conveyor roller running state detection system and method

Abstract

The present application relates to a kind of belt conveyor roller operating state detection system and method, belong to detection technical field.The system includes control system, photoelectric signal conversion system, probe optical cable and stress unit;Wherein photoelectric signal conversion system is connected with control system and probe optical cable respectively;Probe optical cable is arranged in the lower side of the cylinder end surface of roller.By stress unit changes the refractive index of optical fiber in probe optical cable, so that the operating state of roller can be judged based on optical time domain reflection technology and according to the stress change caused by roller rotation, specifically, the Rayleigh scattering light signal generated in optical fiber can be obtained by outputting pulse light signal to probe optical cable, after photoelectric conversion of Rayleigh scattering light signal, analysis and processing, the detection of roller operating state can be realized.The present application method is simple, low in cost, and detection reliability is high.

Description

Technical Field

[0001] The invention belongs to the field of detection technology and relates to a belt conveyor roller operating state detection system and method. Background Art

[0002] Belt conveyors, commonly known as belt conveyors, are essential equipment for transporting materials in coal mines, steel mills, ports, and other industries. They offer advantages such as high transport capacity, long conveying distances, wide conveying ranges, and low operating costs. In belt conveyors, rollers are the core components that pull the conveyor belt and transport materials. Over extended periods of operation, rollers are prone to problems such as seizure, deformation, and breakage, which can damage the belt conveyor and even cause fires.

[0003] Belt conveyor rollers are used extensively in the steel industry, from metallurgical mining to ore dressing, from sintering and pelletizing to ironmaking, and from coal preparation to coking and coke delivery to blast furnaces. Currently, methods for monitoring the operating status of belt conveyor rollers include manual inspections, roller temperature monitoring, and acoustic detection. Manual inspections are labor-intensive and subject to environmental constraints; temperature monitoring indirectly utilizes the temperature rise caused by roller stalling, which is subject to numerous interference factors and poor reliability. Sound signals contain a wealth of on-site environmental information, and fault monitoring by collecting sound has been widely used in industry. However, traditional sound sensors not only require power to operate but are also susceptible to damage. Therefore, it is necessary to develop a belt conveyor roller operating status monitoring system with broad applicability, high reliability, and low cost. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a belt conveyor roller operating status detection system and method, by arranging a detection optical cable under the roller, the rotation status of the roller is detected, and the real-time and accurate detection of the roller operating status is achieved.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] Solution 1: A belt conveyor roller operating status detection system includes a control system, a photoelectric signal conversion system, a detection optical cable, and a stress unit. The photoelectric signal conversion system is connected to the control system and the detection optical cable, respectively; the detection optical cable is arranged on the underside of the cylindrical end face of the roller. The stress unit includes a micro-permanent magnet patch and a micro-iron sheet. The micro-permanent magnet patch is fixed on the circumference of the cylindrical end face of the roller, and the micro-iron sheet is fixed on the detection optical cable at the position closest to the center of the cylindrical end face of the roller.

[0007] Optionally, the photoelectric signal conversion system includes a laser, an optical modulator, an amplifying filter, a circulator and a photodetector connected in sequence; wherein the optical modulator and the photodetector are also connected to the control system respectively, and the circulator is also connected to the detection optical cable.

[0008] Option 2: A method for detecting the operating status of belt conveyor rollers based on the system described in Option 1. This method is based on optical time domain reflection technology. It outputs a pulsed light signal to the detection optical cable to obtain a Rayleigh scattered light signal, converts the Rayleigh scattered light signal into a photoelectric signal, and processes and analyzes the optical time domain reflection signal to realize the detection of the operating status of the belt conveyor rollers.

[0009] Furthermore, the optical time domain reflection signal is processed as follows: a periodic trigger pulse is used as a signal acquisition time unit, the detection optical cable corresponding to each roller is used as a spatial acquisition point, and the optical time domain reflection signal is collected multiple times to construct a spatial response signal matrix and a spatiotemporal response signal matrix, thereby obtaining a time response signal matrix for each spatial acquisition point.

[0010] Furthermore, the optical time domain reflection signal is analyzed specifically as follows: for the time response signal of any spatial collection point, if its signal intensity shows periodic changes, and the change period is the same as the roller rotation period, then the roller corresponding to the spatial collection point is rotating normally; if the signal intensity does not change or the change pattern is abnormal, then the roller corresponding to the spatial collection point is stopped or rotates abnormally.

[0011] Furthermore, the trigger frequency f of the pulse light signal m The following conditions must be met:

[0012]

[0013] Where c is the speed of light in a vacuum, L is the total length of the belt conveyor, and n is g Represents the refractive index of optical fiber.

[0014] Furthermore, the pulse width T of the pulse light signal w , the bandwidth of the photodetector f d And the sampling frequency f of the data logger s Need to meet the following requirements:

[0015]

[0016]

[0017]

[0018] Where c is the speed of light in vacuum, n g represents the refractive index of the optical fiber, and ΔL represents the distance between adjacent rollers.

[0019] Furthermore, the number of time units M must satisfy the following conditions:

[0020]

[0021] In the formula, r represents the speed of the roller when it rotates normally, m is a constant, and f s Indicates the sampling frequency of the data logger.

[0022] The beneficial effects of the present invention are as follows: the present invention applies stress to the detection optical cable through a stress unit, thereby changing the refractive index of the optical fiber, and can judge the operating status of the roller according to the stress change caused by the rotation of the roller through optical time domain reflection technology. The method of the present invention is simple and direct, highly reliable and low in cost.

[0023] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0025] Figure 1 Schematic diagram of the structure of a belt conveyor roller operating status detection system in one embodiment of the present invention;

[0026] Figure 2 This is the layout diagram of the detection optical cable and stress unit in the detection system;

[0027] Figure 3 Schematic diagram of OTDR time and space response signal. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0029] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0030] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] Embodiment 1 of the present invention provides a belt conveyor roller operating status detection system, such as Figure 1 As shown, the system includes a control system, a photoelectric signal conversion system, a detection optical cable and a stress unit.

[0032] The control system includes data processing and controller, data acquisition device and signal generator; the optoelectronic signal conversion system is composed of optical and electrical devices, including ultra-narrow linewidth laser, optical modulator, amplifying filter, circulator and photodetector; the stress unit includes micro permanent magnet patch and micro iron sheet.

[0033] Among them, the data processing and controller can use a computer, or an embedded system with ARM / FPGA / DSP as the core processor; the detection optical cable can use a single-mode communication optical cable.

[0034] Specifically, if Figure 2 As shown, the detection optical cable is fixed to the underside of the cylindrical end face of the belt conveyor roller via a rolling belt, perpendicular to the axis of the roller cylinder. The distance H between the detection optical cable and the outer diameter of the roller is 2.5 mm. A micro permanent magnet patch is fixed to the end face of the roller cylinder near the outer diameter. The micro iron sheet is fixed to the detection optical cable at the position closest to the center of the roller cylinder end face. As the roller rotates periodically, the distance S between the micro permanent magnet patch and the micro iron sheet changes periodically with time t, satisfying the following relationship:

[0035]

[0036] Where T represents the rotation period of the roller.

[0037] Embodiment 2 of the present invention provides a method for detecting the operating status of a belt conveyor roller, which is as follows:

[0038] 1) The data processing and controller sends a control signal to the signal generator;

[0039] 2) The ultra-narrow linewidth laser emits a highly coherent continuous light wave. The optical modulator modulates the continuous light wave into a pulsed light signal under the action of the signal generator. The modulated pulsed light signal is amplified and filtered before being injected into the optical fiber of the detection cable through a circulator.

[0040] 3) The pulsed light signal is transmitted forward along the optical fiber, and at the same time, a Rayleigh scattered light signal is generated in the reverse direction;

[0041] 4) The returned Rayleigh scattered light signal is received by the circulator, and the stress unit’s action signal on the optical fiber is obtained, which is then converted into an electrical signal by a photodetector.

[0042] 5) The data collector transmits the collected signals to the data processing and controller to process and analyze the collected optical time domain reflectometry (OTDR) signals to obtain the test results.

[0043] In order to ensure that the sensing distance of the detection optical cable can cover the entire belt conveyor, the trigger frequency f of the pulse light signal in step 2) is m Need to meet:

[0044]

[0045] Where c is the speed of light in a vacuum, L is the total length of the belt conveyor, and n is g Indicates the refractive index of the optical fiber.

[0046] In order to ensure that the spatial resolution of the detection cable can distinguish two adjacent rollers, the pulse width T w , the bandwidth of the photodetector f d , the sampling frequency f of the data logger s Need to meet:

[0047]

[0048]

[0049]

[0050] Wherein, ΔL represents the distance between adjacent rollers.

[0051] The specific steps of processing the optical time domain reflectometry signal in step 5) are as follows:

[0052] a. Take a periodic trigger pulse as a signal acquisition time unit. The signal collected in this time unit is an exponentially decaying OTDR track distributed along the detection optical cable. Suppose the signal collected in the kth signal acquisition time unit is:

[0053] X k ={s ki (i=1,2,…,N)}

[0054] Where i represents the sequence number of the spatial collection point, and N represents the number of spatial collection points.

[0055] b. As k increases, the spatially distributed OTDR traces are periodically refreshed. When M OTDR traces are continuously accumulated, as shown in Figure 3 As shown, a space-time response signal matrix with N dimensions in space and M dimensions in time can be constructed:

[0056] XY={s ki (k=1,2,…,M; i=1,2,…,N)}

[0057] Wherein, k represents the sequence number of the time collection point, and M represents the number of time collection points.

[0058] c. The time response signal of the i-th spatial acquisition point is obtained as follows:

[0059] Y i ={s ki (k=1,2,…,M)}

[0060] d. For the time domain signal Y of any spatial acquisition point i i If the signal strength shows periodic changes, and the change period is the same as the roller vibration period, then the roller corresponding to the spatial acquisition point i rotates normally; if the signal strength does not change or the change pattern is abnormal, then the roller corresponding to the spatial acquisition point i stops rotating or rotates abnormally.

[0061] The number of spatial collection points N is equal to the number of rollers, so the spatial collection point i corresponds to the roller one-to-one; and the number of time collection points M needs to satisfy:

[0062]

[0063] Wherein, m is 3 to 10, and r represents the speed of the roller during normal rotation, in r / min.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for detecting the operating status of a belt conveyor roller, characterized in that: The invention comprises a belt conveyor roller operation status detection system, which includes a control system, a photoelectric signal conversion system, a detection optical cable and a stress unit; the stress unit includes a micro permanent magnet patch and a micro iron sheet; the photoelectric signal conversion system is connected to the control system and the detection optical cable respectively; the detection optical cable is arranged on the lower side of the end face of the roller cylinder; the micro permanent magnet patch is fixed on the circumference of the end face of the roller cylinder; the micro iron sheet is fixed on the detection optical cable at the position closest to the center of the end face of the roller cylinder; The photoelectric signal conversion system is used to output a pulsed optical signal to the detection optical cable, collect the Rayleigh scattered light signal transmitted in the reverse direction in the detection optical cable, and perform photoelectric conversion to obtain an optical time domain reflection signal; the control system processes the optical time domain reflection signal and determines the operating status of the roller, including using a periodic trigger pulse as a signal collection time unit, taking the position corresponding to each roller on the detection optical cable as a spatial collection point, collecting the optical time domain reflection signal multiple times to construct a spatial response signal matrix and a spatiotemporal response signal matrix, respectively, to obtain a time response signal matrix for each spatial collection point; for the time response signal of any spatial collection point, if its signal strength shows periodic changes, and the change period is the same as the roller rotation period, then the roller corresponding to the spatial collection point is rotating normally; If the signal strength does not change or the change pattern is abnormal, the roller corresponding to the spatial collection point has stopped rotating or is rotating abnormally.

2. The belt conveyor roller operating status detection method according to claim 1, characterized in that: The photoelectric signal conversion system includes a laser, an optical modulator, an amplifying filter, a circulator and a photoelectric detector connected in sequence; the optical modulator and the photoelectric detector are respectively connected to a control system, and the circulator is connected to a detection optical cable.

3. The belt conveyor roller operating status detection method according to claim 1, characterized in that: Trigger frequency of pulsed light signal f m The following conditions must be met: Where, c is the speed of light in vacuum, L Indicates the total length of the belt conveyor. Represents the refractive index of optical fiber.

4. The belt conveyor roller operating status detection method according to claim 1, characterized in that: Pulse width of pulsed light signal , the bandwidth of the photodetector and the sampling frequency of the data logger Need to meet the following requirements: Where, c is the speed of light in vacuum, represents the refractive index of the optical fiber, Indicates the distance between adjacent rollers.

5. The belt conveyor roller operating status detection method according to claim 1, characterized in that: Number of time units M The following conditions must be met: Where, r Indicates the speed of the roller when it rotates normally. m is a constant, Indicates the sampling frequency of the data logger.

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