A belt conveyor speed measurement system and method

Abstract

This application primarily relates to the field of bulk cargo handling equipment technology, specifically to a belt conveyor speed measurement system and method. This application provides a belt conveyor speed measurement system applied to a rotating component associated with the belt's running speed. The system includes a sensing block mounted on the rotating component and rotating synchronously with it; a non-contact limit unit mounted on the outside of the rotating component and spaced apart from the sensing block, used to output a state switching signal when the sensing block enters or leaves the sensing area as the rotating component rotates; and a programmable logic controller electrically connected to the non-contact limit unit, used to receive the state switching signal and, based on preset detection conditions and whether the state switching signal is received within a preset detection time, determine whether the belt conveyor has experienced underspeed or slippage. The system provided by this application not only saves costs but also improves efficiency.

Description

Technical Field

[0001] This application mainly relates to the field of bulk cargo loading and unloading equipment technology, and specifically to a belt conveyor speed measurement system and method. Background Technology

[0002] In the automated control systems of bulk cargo handling equipment (such as belt conveyors), real-time and accurate detection of belt speed is a crucial element in ensuring safe equipment operation and achieving precise metering and process control. Currently, the belt speed measurement systems commonly used in this field are mainly based on electronic pulse speed sensors.

[0003] Electronic pulse speed sensors typically align a speed sensor (such as a proximity switch or encoder) with a metal detection plate (or sensing gear) mounted on a rotating shaft (such as a driven roller shaft or a speed measuring roller shaft). As the shaft rotates, the detection plate periodically passes through the sensor, generating a series of pulse electrical signals. The frequency of this pulse signal is proportional to the rotational speed of the shaft. By detecting this frequency, the control system can calculate the shaft speed and thus obtain the actual linear speed of the belt.

[0004] However, dedicated electronic pulse speed sensors are expensive, and the market offers a wide variety of models and brands with inconsistent interfaces and electrical parameters. The lack of industry-standard product selection leads to inconvenience in procurement and spare parts management. These sensors typically incorporate manufacturer-specific software programs or processing algorithms. After on-site installation, specialized parameter settings and debugging by the equipment manufacturer's technicians are required, increasing the complexity and time cost of on-site construction. Furthermore, to accurately capture high-speed pulse signals, the main control system must be equipped with a dedicated high-speed pulse counting module (such as a high-speed counter in a PLC). Different projects or different brands of sensors require different PLC processing programs, resulting in poor program versatility and hindering standardized equipment design and subsequent maintenance. This increases the hardware requirements for the core controller and raises the overall cost of the control system.

[0005] In summary, existing belt speed measurement systems based on dedicated pulse sensors have many limitations in terms of cost control, standardized design, ease of installation and commissioning, and system integration complexity. Summary of the Invention

[0006] This application provides a belt speed measuring system that can solve the problems of high cost and inconvenient installation and debugging of existing speed measuring sensors.

[0007] This application provides a belt conveyor speed measurement system to solve the above-mentioned technical problems. The system is applied to rotating components associated with belt running speed and includes a sensing block, a non-contact limit unit, and a programmable logic controller. The sensing block is mounted on the rotating component and rotates synchronously with the rotating component; The non-contact limiting unit is installed on the outside of the rotating component and arranged at intervals with the sensing block, and is used to output a state switching signal when the sensing block enters or leaves the sensing area as the rotating component rotates. The programmable logic controller is electrically connected to the non-contact limit unit and is used to receive the state switching signal and determine whether the belt conveyor has experienced underspeed or slippage faults based on whether the state switching signal is received within a preset detection time under preset detection conditions.

[0008] In one embodiment of this application, the non-contact limiting unit, The sensing block is detected by oscillating electromagnetic induction; A first status signal is output in response to the detection that the sensing block has entered the sensing area; A second state signal is output in response to the detection that the sensing block has left the sensing area.

[0009] In one embodiment of this application, the preset detection conditions include: Speed ​​measurement is performed only when the belt conveyor is in a stable operating phase, and the belt starts to accelerate and decelerates on a ramp.

[0010] In one embodiment of this application, the programmable logic controller further includes: The stable operation detection stage is determined based on the speed signal fed back by the frequency converter, and the speed measurement judgment is initiated when the belt speed reaches the preset speed threshold.

[0011] In one embodiment of this application, the preset detection time, Determined based on the single rotation time of the rotating component at the rated speed and the preset speed threshold; If the programmable logic controller does not receive the state switching signal within the preset detection time, it determines that the belt conveyor has experienced underspeed or slippage fault.

[0012] In one embodiment of this application, the preset detection time is T / (2k); Where T is the time required for the rotating component to rotate one revolution at the rated speed, and k is the ratio of the preset speed threshold to the rated speed, where 0 < k ≤ 1.

[0013] In one embodiment of this application, the sensing block is a semi-circular metal block.

[0014] In one embodiment of this application, a mounting bracket is also included: The mounting bracket includes steel plate components and angle steel components, which are used to fix the non-contact limiting unit in a preset position and maintain a preset sensing distance between the non-contact limiting unit and the sensing block.

[0015] In one embodiment of this application, the programmable logic controller further includes: A timing unit is used to start timing when the detection conditions are met and the state switching signal is not received, and to filter instantaneous abnormal signals; The fault latch unit is used to hold the fault event after a fault is established until a reset signal is received; Bypass unit, used to shield fault output when bypass is enabled; The output unit is used to output fault event signals and / or bypass status signals to the human-machine interface or host computer.

[0016] To solve the above-mentioned technical problems, this application also proposes a belt conveyor speed measurement method, which is implemented using the belt conveyor speed measurement system described above, characterized in that it includes: A sensing block is installed on the rotating component that is associated with the belt running speed, and a non-contact limit unit is set at the corresponding position; The sensing block rotates synchronously with the rotating component, and outputs a state switching signal when it enters or leaves the sensing area of ​​the non-contact limiting unit. The programmable logic controller receives the state switching signal and establishes preset detection conditions for speed measurement and determination based on the belt conveyor's operating status. In response to the satisfaction of the preset detection condition, it is determined whether the state switching signal is received within the preset detection time. If the state switching signal is not received within the preset detection time, it is determined that the belt conveyor has an underspeed or slippage fault, and an alarm or shutdown control signal is output.

[0017] This application provides a belt conveyor speed measurement system and method that replaces the traditional speed sensor with a non-contact limit unit, eliminating the need for a dedicated high-speed pulse counter. This saves costs, fully meets the belt speed measurement function, reduces the complexity and cost of system hardware configuration, improves efficiency, standardizes design selection, and facilitates batch design, manufacturing, installation, and maintenance. Attached Figure Description

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 A structural diagram of a belt conveyor speed measuring system according to an embodiment of this application is disclosed; Figure 2A schematic diagram of the structure of a conventional speed sensor has been revealed; Figure 3 A schematic diagram of the structure of a standardized non-contact limiting unit according to an embodiment of this application is disclosed; Figure 4 A first schematic diagram of a standardized mounting bracket structure according to an embodiment of this application is disclosed; Figure 5 A second schematic diagram of a standardized mounting bracket structure according to an embodiment of this application is disclosed; Figure 6 A schematic diagram of the structure of an inductive collision block according to an embodiment of this application is disclosed; Figure 7 A schematic diagram of the installation structure of the sensing block according to an embodiment of this application is disclosed. Detailed Implementation

[0019] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0021] Furthermore, the terms “up,” “down,” “left,” “right,” “top,” “bottom,” “horizontal,” and “vertical” used in the following description should be understood as the orientations shown in the paragraph and related figures. This relative terminology is for illustrative purposes only and does not imply that the described device must be manufactured or operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] It is understood that although terms such as "first," "second," and "third" may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first component, region, layer, and / or part discussed below may be referred to as the second component, region, layer, and / or part without departing from some embodiments of this application.

[0023] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0024] This application provides a belt conveyor speed measurement system that uses a standardized non-contact limit unit to replace the traditional complex and expensive electronic pulse speed sensor. By detecting the signal passed by a metal stopper mounted on a rotating shaft such as a roller, and combining this signal with a standardized logic program within a programmable logic controller, accurate monitoring of the belt speed is achieved.

[0025] Figure 1 A structural diagram of a belt conveyor speed measuring system according to an embodiment of this application is disclosed, as follows: Figure 1 As shown, a belt conveyor speed measuring system 10, applicable to rotating components related to belt running speed, includes a sensing block 1, a non-contact limit unit 2, and a programmable logic controller 3. The sensing block 1 is mounted on the rotating component and rotates synchronously with the rotating component; The non-contact limiting unit 2 is installed on the outside of the rotating component and arranged at intervals with the sensing block 1, and is used to output a state switching signal when the sensing block 1 enters or leaves the sensing area as the rotating component rotates. The programmable logic controller 3 is electrically connected to the non-contact limit unit 2 and is used to receive the state switching signal and determine whether the belt conveyor has experienced underspeed or slippage faults based on whether the state switching signal is received within a preset detection time under preset detection conditions.

[0026] This application provides a belt conveyor speed measurement system that can be applied to the rollers of a belt conveyor or rotating components related to the belt running speed. By using a non-contact limit unit to replace the traditional speed sensor, there is no need to configure a dedicated high-speed pulse counter. On the one hand, it can save costs and fully meet the belt speed measurement function, reducing the complexity and cost of system hardware configuration. On the other hand, it can improve efficiency. Based on a unified model of inductive limit, a standardized bracket, a standardized impact block, and a standardized installation scheme are constructed to achieve standardized design and selection, which is convenient for batch design, manufacturing, installation, and maintenance.

[0027] The various modules of the belt conveyor speed measurement system proposed in this application will be described in detail below. It should be understood that, within the scope of this application, the above-mentioned technical features of this application and the technical features specifically described below (such as in the embodiments) can be combined and related to each other to form a preferred technical solution.

[0028] The sensing block 1 is mounted on the rotating component and rotates synchronously with the rotating component.

[0029] The sensing block 1 can be fixedly installed on the belt conveyor drum or rotating shaft and rotate synchronously with the drum or rotating shaft.

[0030] In one embodiment, the sensing block is a semi-circular metal block.

[0031] The non-contact limiting unit 2 is installed on the outside of the rotating component and arranged at intervals with the sensing block 1, and is used to output a state switching signal when the sensing block 1 enters or leaves the sensing area as the rotating component rotates.

[0032] The non-contact limiting unit 2 is fixed to a position adjacent to the sensing block 1 by a mounting bracket, so that the sensing block 1 can periodically enter the sensing area of ​​the non-contact limiting unit 2 during the rotation of the roller or rotating shaft.

[0033] In one embodiment, the non-contact limiting unit further includes: The sensing block is detected by oscillating electromagnetic induction; A first status signal is output in response to the detection that the sensing block has entered the sensing area; A second state signal is output in response to the detection that the sensing block has left the sensing area.

[0034] In this embodiment, the first state signal is a closed state signal, and the second state signal is an open state signal.

[0035] When the sensing block 1 approaches, the non-contact limiting unit 2 outputs a closed signal; when the sensing block 1 moves away, the non-contact limiting unit 2 returns to an open signal.

[0036] Preferably, the non-contact limit unit 2 is an inductive non-contact proximity switch. Its working principle is as follows: the internal oscillation circuit generates a high-frequency alternating electromagnetic field. When the metal sensing block 1 enters the sensing area, eddy currents are generated on the surface of the sensing block 1. The eddy currents consume energy, causing the state (amplitude / phase / frequency) of the internal oscillation circuit of the sensor to change. After processing by the internal detection circuit, the on / off state change signal is output. When the change reaches the preset threshold, the output state signal is triggered to switch between 1 (closed) and 0 (open).

[0037] Since this detection method does not require mechanical contact with the sensing block 1, it can reduce mechanical wear, increase service life, and adapt to complex working conditions such as vibration, dust, humidity and salt spray at the port site.

[0038] In this embodiment, the non-contact limiting unit 2 can be an industrial-grade product with short-circuit protection, reverse polarity protection and wire breakage protection functions, and its protection level is preferably not lower than IP67.

[0039] Figure 2 A schematic diagram of the structure of a conventional speed sensor is shown, such as... Figure 2 As shown, the existing electronic pulse sensor 20 incorporates a built-in start-up compensation timer 21, a proximity switch 22, a digital switch 23, a power terminal 24, an output terminal 25, an indicator light 26, an amplifier, etc. The proximity switch 22 is installed next to the monitored rotating equipment (such as a motor shaft or driven wheel). When the equipment rotates, the metal detection plate / gear ring on the shaft periodically passes through the switch's sensing area, causing the switch to output a pulse signal, indicating that the equipment is rotating. The digital switch 23 (DIP switch setting) is used to set the alarm speed threshold. When the equipment speed falls below this value, protection is triggered. The power terminal 24 provides power, typically an AC / DC industrial power supply. The output terminal 25 is used to connect external relays, PLCs, or control circuits to achieve shutdown and alarm linkage.

[0040] This type of electronic pulse sensor 20 comes with a built-in manufacturer-set speed value and programmed software. It requires on-site guidance and debugging from the manufacturer, and also requires the host electronic control PLC (programmable logic controller) system to be configured with a high-speed pulse counter to detect pulses.

[0041] This application provides a belt conveyor speed measurement system that adopts a non-contact limit unit design, requiring only one inductive limit switch to achieve the speed measurement function. The system does not require built-in DIP switches and start compensators, does not require parameter settings or programming by the manufacturer, and does not require a separate high-speed counter configured on the main PLC. Speed ​​measurement can be completed using a common DI (digital input) module of the main PLC.

[0042] Figure 3 A schematic diagram of the structure of a standardized non-contact limiting unit according to an embodiment of this application is disclosed, as follows: Figure 3 As shown, a standardized non-contact limiting unit 30 has an M30×1.5LED thread specification, an LED indicator 31 at the tail, a total length of approximately 60mm, an effective thread length of approximately 55mm, and a head sensing area length of 15mm. The sensing area of ​​the head generates a high-frequency alternating magnetic field. When a metal object (sensing impact block) approaches, it changes the eddy current loss of the magnetic field. After the sensor's internal circuit detects the change, it outputs a switching signal (on / off). Specific parameters are as follows:

[0043] In one embodiment, a mounting bracket is also included: The mounting bracket is used to install the non-contact limiting unit; The mounting bracket includes steel plate components and angle steel components, which are used to fix the non-contact limiting unit in a preset position and maintain a preset sensing distance between the non-contact limiting unit and the sensing block.

[0044] Figure 4 A first schematic diagram of a standardized mounting bracket structure according to an embodiment of this application is disclosed. Figure 5 A second schematic diagram of a standardized mounting bracket structure according to an embodiment of this application is disclosed. Figure 5 This is the main view. Figure 4 yes Figure 5 Side view, such as Figure 4 and Figure 5 As shown, the mounting bracket includes a first steel plate 41, a second steel plate 42, and an angle steel 43. The first steel plate 41 and the second steel plate 42 form the mounting base, the angle steel 43 is used for reinforcement, support, and connection, and the non-contact limiting unit 44 is standardizedly installed on the mounting bracket, wherein the standardized installation maintains the preset position and sensing distance.

[0045] The mounting bracket provides a stable fixed position for the non-contact limiting unit 44, ensuring that the sensing surface of the non-contact limiting unit 44 faces the sensing block 45 (see [reference]). Figure 7 The movement trajectory of the non-contact limiting unit 44 and the sensing block 45 is controlled by structural dimensions to maintain a suitable sensing distance, thereby facilitating unified processing, installation and replacement on site.

[0046] Unlike existing speed sensors that require separate mounting brackets for different models, this application designs a mounting bracket around a non-contact limiting unit 44 of uniform specifications, which can significantly improve the standardization of the installation structure.

[0047] Figure 6 A schematic diagram of the structure of a sensing block according to an embodiment of this application is disclosed. Figure 7 A schematic diagram of the mounting structure of the sensing block according to an embodiment of this application is disclosed, as shown below. Figure 6 As shown, the sensing block 45 is preferably made of metal, and more preferably has a semi-circular structure. The semi-circular structure facilitates smooth passage through the sensing area during rotation and also simplifies manufacturing and installation. Figure 7 As shown, the sensing block 45 can be installed on the drum or rotating shaft by welding, bolting or other reliable fixing methods, and will not loosen or shift during long-term operation.

[0048] In practical applications, the material, size and installation position of the sensing block 45 can be adjusted according to the sensing limit model, sensing distance, roller size and on-site installation space, but it should be ensured that the sensing block 45 triggers the non-contact limit unit 44 to switch output states at least once in each rotation or predetermined angle.

[0049] The programmable logic controller 3 is electrically connected to the non-contact limit unit and is used to receive the state switching signal and determine whether the belt conveyor has experienced underspeed or slippage faults based on whether the state switching signal is received within a preset detection time under preset detection conditions.

[0050] The output of the non-contact limit unit is directly connected to the programmable logic controller 3, and the programmable logic controller 3 does not need to be specially configured with a high-speed pulse counter module.

[0051] Unlike traditional electronic pulse speed sensors, this application does not rely on real-time high-speed counting of high-frequency pulses. Instead, it detects the on / off state changes formed when the sensing block passes periodically and collects the time interval between adjacent effective trigger signals to determine the roller rotation cycle and belt running status.

[0052] Therefore, the speed measurement system of this application is simpler in terms of hardware access, requires less work in field wiring and PLC configuration, and can be more easily embedded into the existing belt conveyor main control system.

[0053] In terms of cost, the system has achieved a significant cost reduction, with a 95% reduction per unit. It replaces the expensive electronic pulse sensor with a low-cost non-contact limit unit, resulting in a 98.5% reduction in the cost of core components. It abandons the dedicated high-speed counter module and directly reuses the existing ordinary DI module, reducing the PLC cost to zero. Furthermore, all debugging and installation processes have been changed to internal / simplified methods, further reducing labor and service costs and achieving a precipitous drop in costs.

[0054] In terms of installation, the non-contact limit unit of this system is a standard model, and the mounting bracket is manufactured according to the limit standard, taking up little space. In terms of efficiency, the system debugging cycle is shortened from about 1 day to 2 hours, improving efficiency by 90%; the conventional system experiences about 4 downtimes per month due to pulse signal loss, while the signal loss rate of the belt conveyor speed measurement system provided in this application is reduced to 0 times per month.

[0055] In one embodiment, the preset detection conditions include: Speed ​​measurement is performed only when the belt conveyor is in a stable operating phase, and the belt starts to accelerate and decelerates on a ramp.

[0056] The programmable logic controller further includes: The stable operation detection stage is determined based on the speed signal fed back by the frequency converter, and the speed measurement judgment is initiated when the belt speed reaches a preset speed threshold, wherein the preset speed threshold is 80% of the rated speed of the belt.

[0057] To avoid false alarms during the belt conveyor's acceleration phase or deceleration phase on a slope, in this embodiment, the programmable logic controller (PLC) is linked with the speed feedback signal of the frequency converter to set up speed fault detection shielding logic.

[0058] Specifically, when the belt conveyor is in the startup acceleration phase, the drum speed has not yet reached the stable operating range, and the cycle of the sensing block passing through the non-contact limit unit is relatively long. If underspeed monitoring is activated immediately, it is easy to cause misjudgment. Therefore, in the initial stage of startup, the programmable logic controller temporarily disables the speed fault detection function based on the inverter's operating status or speed feedback signal.

[0059] Similarly, when the belt conveyor enters the ramp deceleration stage, the induction signal period will also be extended as the drum speed decreases in a controlled manner. The programmable logic controller can also shield the speed measurement fault detection according to the deceleration state.

[0060] The programmable logic controller (PLC) activates the speed fault detection function only when the frequency converter feedback indicates that the belt conveyor has entered a stable operating range. This improves the accuracy of the speed measurement system in identifying real underspeed and slippage faults.

[0061] In one embodiment, the preset detection time includes: Determined based on the single rotation time of the rotating component at the rated speed and the preset speed threshold; When the programmable logic controller does not receive the state switching signal within the preset detection time, it determines that the belt conveyor has an underspeed or slippage fault.

[0062] In one embodiment, the preset detection time is T / (2k), where T is the time required for the rotating component to rotate one revolution at the rated speed, and 0 < k ≤ 1, and k is the ratio of the preset speed threshold to the rated speed.

[0063] In this embodiment, the programmable logic controller uses fault determination logic based on the rated speed proportional threshold and time threshold to determine whether the belt conveyor is underspeeding or slipping.

[0064] Using the rated operating speed of the belt conveyor as a benchmark, the speed measurement threshold is set to 80% of the rated speed. If the time required for the drum to complete one full rotation is 0.5 seconds when the belt conveyor is running stably, then when the belt conveyor is running at 80% of the rated speed, the time required for the drum to complete one full rotation is: 0.5 × 1 / 0.8 = 0.625 seconds. The corresponding half-rotation time is approximately 0.3125 seconds, so 0.3 seconds can be taken as the fault determination time threshold.

[0065] When the programmable logic controller detects that the belt conveyor has entered the normal monitoring range, and does not receive a valid feedback signal from the non-contact limit unit within the preset time threshold for more than 0.3 seconds, it determines that the belt conveyor has an underspeed or slippage fault and outputs an alarm signal or a shutdown control signal.

[0066] The belt conveyor speed measurement system provided in this application implements standardized programming in terms of software configuration: The detection condition is that the belt speed reaches 80% of the rated speed. The PLC automatically blocks the speed signals fed back from the frequency converter during the acceleration phase and the deceleration phase. Taking 0.5 seconds for one rotation of the drum as an example, when the belt is running at 80% speed, one rotation takes 0.625 seconds, and half a rotation takes 0.3 seconds. If the PLC does not detect the drum's limit switch signal within 0.3 seconds, it determines that the belt is underspeeding or slipping, outputs a fault alarm signal, and stops the belt conveyor.

[0067] In one embodiment, the programmable logic controller (PLC) can use standard function blocks to implement speed measurement fault detection. Taking function block FB2502 as an example, its logic includes functions such as timing detection, fault latching, fault bypass, and status output.

[0068] In one embodiment, the programmable logic controller further includes: A timing unit is used to start timing when the detection conditions are met and the state switching signal is not received, and to filter instantaneous abnormal signals; The fault latch unit is used to hold the fault event after a fault is established until a reset signal is received; Bypass unit, used to shield fault output when bypass is enabled; The output unit is used to output fault event signals and / or bypass status signals to the human-machine interface or host computer.

[0069] In this embodiment, the operation of the programmable logic controller can be specifically described as follows: When the "fault detection conditions are met" and "there is no normal feedback from the system", the detection timer is started. If the abnormal state continues for more than the preset filtering time, the abnormality is considered valid, and the filtered fault trigger signal is output. "No normal feedback from the system" means that, in cases such as damage to the non-contact limit unit, belt stoppage, or damage to the programmable logic controller (PLC), the PLC does not receive the limit pulse signal.

[0070] The fault event status remains true when the filtered fault trigger signal is true, or when a fault has been triggered but no reset operation has been performed.

[0071] The system will only output a fault signal when the fault event is true and the bypass function is not enabled.

[0072] Both fault events and bypass status are transmitted to the host computer or HMI (human-machine interface) so that the operator can intuitively view the current status (e.g., the touch screen displays "speed over limit fault" or "fault bypass is enabled").

[0073] By setting the filtering time, false alarms can be avoided due to jitter, short-term fluctuations, or the influence of the CPU scan cycle.

[0074] This application also provides a method for measuring the speed of a belt conveyor, implemented using the belt conveyor speed measuring system described above, the method comprising: A sensing block is installed on the rotating component that is associated with the belt running speed, and a non-contact limit unit is set at the corresponding position; The sensing block rotates synchronously with the rotating component, and outputs a state switching signal when it enters or leaves the sensing area of ​​the non-contact limiting unit. The programmable logic controller receives the state switching signal and establishes preset detection conditions for speed measurement and determination based on the belt conveyor's operating status. In response to the satisfaction of the preset detection condition, it is determined whether the state switching signal is received within the preset detection time. If the state switching signal is not received within the preset detection time, it is determined that the belt conveyor has an underspeed or slippage fault, and an alarm or shutdown control signal is output.

[0075] The belt conveyor speed measurement system and method provided in this application have the following technical advantages: 1) This application uses a non-contact limit unit to replace the traditional electronic pulse speed sensor, which eliminates the need for a dedicated high-speed pulse counter and reduces the complexity and cost of system hardware configuration.

[0076] 2) This application can build standardized brackets, standardized impact blocks and standardized installation schemes around a unified model of non-contact limit unit. It occupies little space, is easy to design, manufacture, install and maintain in batches, and has no mechanical contact wear. It has good vibration resistance, dustproof, waterproof and corrosion resistance, and is suitable for port environments with high salt spray, high humidity and strong vibration.

[0077] 3) The belt conveyor speed measurement system provided in this application can complete the speed measurement status acquisition by using a PLC ordinary digital input module, without relying on a high-speed pulse acquisition unit, forming a standardized PLC function block, saving costs and improving efficiency. The debugging cycle of a conventional belt speed measurement system is about 1 day, while the system provided in this application is shortened to 2 hours, improving efficiency by 90%, and there is no signal loss (conventional belt speed measurement systems cause multiple shutdowns due to pulse signal loss), achieving standardized design and selection, and fully meeting the belt speed measurement function.

[0078] It should be understood that the embodiments described above are merely illustrative. The embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For hardware implementation, the processor may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and / or other electronic units designed to perform the functions described herein, or combinations thereof.

[0079] Some aspects of this application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "component," or "system." The processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. Furthermore, aspects of this application may manifest as computer products residing in one or more computer-readable media, including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, etc.), optical discs (e.g., compressed CDs, digital multifunction DVDs, etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0080] A computer-readable medium may contain a propagated data signal containing computer program code, for example, on baseband or as part of a carrier wave. This propagated signal may take various forms, including electromagnetic, optical, and so on, or suitable combinations thereof. A computer-readable medium can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to enable communication, propagation, or transmission of a program for use. The program code located on the computer-readable medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, radio frequency signals, or similar media, or any combination of the above media.

[0081] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0082] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0083] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used to describe embodiments are sometimes modified by the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in this application are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

Claims

1. A belt conveyor speed measurement system, characterized in that, Applications to rotating components related to belt speed include inductive stop blocks, non-contact limit units, and programmable logic controllers: The sensing block is mounted on the rotating component and rotates synchronously with the rotating component; The non-contact limiting unit is installed on the outside of the rotating component and arranged at intervals with the sensing block, and is used to output a state switching signal when the sensing block enters or leaves the sensing area as the rotating component rotates. The programmable logic controller is electrically connected to the non-contact limit unit and is used to receive the state switching signal and determine whether the belt conveyor has experienced underspeed or slippage faults based on whether the state switching signal is received within a preset detection time under preset detection conditions.

2. The belt conveyor speed measurement system as described in claim 1, characterized in that, The non-contact limiting unit. The sensing block is detected by oscillating electromagnetic induction; A first status signal is output in response to the detection that the sensing block has entered the sensing area; A second state signal is output in response to the detection that the sensing block has left the sensing area.

3. The belt conveyor speed measurement system as described in claim 1, characterized in that, The preset detection conditions include: Speed ​​measurement is performed only when the belt conveyor is in a stable operating phase, and the belt starts to accelerate and decelerates on a ramp.

4. The belt conveyor speed measurement system as described in claim 3, characterized in that, The programmable logic controller further includes: The stable operation detection stage is determined based on the speed signal fed back by the frequency converter, and the speed measurement judgment is initiated when the belt speed reaches the preset speed threshold.

5. The belt conveyor speed measurement system as described in claim 4, characterized in that, The preset detection time Determined based on the single rotation time of the rotating component at the rated speed and the preset speed threshold; If the programmable logic controller does not receive the state switching signal within the preset detection time, it determines that the belt conveyor has experienced underspeed or slippage fault.

6. The belt conveyor speed measurement system as described in claim 5, characterized in that, The preset detection time is T / (2k); Where T is the time required for the rotating component to rotate one revolution at the rated speed, and k is the ratio of the preset speed threshold to the rated speed, where 0 < k ≤ 1.

7. The belt conveyor speed measurement system as described in claim 1, characterized in that, The sensing block is a semi-circular metal block.

8. The belt conveyor speed measurement system as described in claim 1, characterized in that, Also includes mounting brackets: The mounting bracket includes steel plate components and angle steel components, which are used to fix the non-contact limiting unit in a preset position and maintain a preset sensing distance between the non-contact limiting unit and the sensing block.

9. The belt conveyor speed measuring system according to claim 4, characterized in that, The programmable logic controller further includes: A timing unit is used to start timing when the detection conditions are met and the state switching signal is not received, and to filter instantaneous abnormal signals; The fault latch unit is used to hold the fault event after a fault is established until a reset signal is received; Bypass unit, used to shield fault output when bypass is enabled; The output unit is used to output fault event signals and / or bypass status signals to the human-machine interface or host computer.

10. A method for measuring the speed of a belt conveyor, implemented using the belt conveyor speed measuring system as described in any one of claims 1-9, characterized in that, include: A sensing block is installed on the rotating component that is associated with the belt running speed, and a non-contact limit unit is set at the corresponding position; The sensing block rotates synchronously with the rotating component, and outputs a state switching signal when it enters or leaves the sensing area of ​​the non-contact limiting unit. The programmable logic controller receives the state switching signal and establishes preset detection conditions for speed measurement and determination based on the belt conveyor's operating status. In response to the satisfaction of the preset detection condition, it is determined whether the state switching signal is received within the preset detection time. If the state switching signal is not received within the preset detection time, it is determined that the belt conveyor has an underspeed or slippage fault, and an alarm or shutdown control signal is output.

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