Online monitoring method and device for conveyor protection device, equipment and medium

Abstract

The invention relates to the technical field of conveyor protection monitoring, and discloses an online monitoring method and device for a conveyor protection device, equipment and a medium. According to the method, a two-wire system carrier address encoder is used for collecting operation state parameters of the conveyor protection device, and carrier modulation is carried out after the operation state parameters are converted into digital signals. In a modulation process, data channels corresponding to different address encoders are distinguished by adopting a frequency division multiplexing technology, so that a modulation signal containing an equipment address identifier and state information is generated. And then the direct-current power supply and the modulation signal are synchronously transmitted to the central processing unit through the same two-core cable. At a central processing unit end, a signal separation technology is used to extract modulation signals and demodulate the modulation signals, and state data corresponding to each address encoder is restored. And establishing a running state database of the conveyor protection device according to the restored state data. According to the online monitoring method and device for the conveyor protection device, the equipment and the medium, the accuracy of online monitoring of the conveyor can be improved.

Description

Technical Field

[0001] This invention relates to the field of conveyor protection and monitoring technology, specifically to online monitoring methods, devices, equipment, and media for conveyor protection devices. Background Technology

[0002] Conveyors, as indispensable key equipment in industrial production, play a vital role in numerous fields. In the mining industry, from underground ore extraction to surface transportation and material handling in ore processing plants, conveyors undertake the task of transporting large volumes of materials over long distances. For example, a 13-kilometer-long belt conveyor used in an Australian iron ore mine efficiently transports ore from the mining area to the port, significantly improving transportation efficiency and reducing costs. In the logistics sector, whether it's sorting goods in e-commerce warehouses or handling parcels at express delivery stations, conveyors enable the rapid and orderly transport of materials, achieving efficient distribution and delivery, and greatly improving the efficiency of logistics operations. In port operations, enclosed tubular conveyors are commonly used at bulk cargo terminals to transport bulk cargo such as iron ore. The conveyor belt is coiled into a cylindrical shape to wrap the material, preventing spillage and dust generation. It can also be arranged in curved sections to adapt to complex terminal terrain, enabling rapid loading and unloading of containers or bulk cargo, effectively shortening ship berthing time. In addition, conveyors also play an important role in industries such as power, chemical, and food, serving as key equipment to ensure the smooth operation of production processes.

[0003] Traditional methods for monitoring conveyor protection devices largely rely on manual inspections. Workers need to check each component of the conveyor at regular intervals for any abnormalities. This method is not only labor-intensive but also has a long monitoring cycle, often taking a day or even several days to complete a full inspection. During the time between inspections, equipment malfunctions are difficult to detect in a timely manner. For example, in mining environments, due to the wide distribution of conveyors and harsh working conditions, manual inspections are difficult and cannot provide real-time monitoring of equipment operation. This means that potential faults may go undetected, potentially leading to sudden equipment failures and disrupting production continuity.

[0004] When conveyors malfunction, existing technologies often struggle to pinpoint the exact location of the fault. Taking belt conveyors as an example, various fault types may exist, such as belt misalignment, tearing, and idler damage. Traditional monitoring technologies lack effective fault diagnosis and location methods, only able to roughly determine the area of ​​the fault, unable to pinpoint its exact location. This forces maintenance personnel to spend considerable time and effort locating the fault, delaying repairs, extending equipment downtime, and severely impacting production efficiency. For instance, in a coal mine, the inability to quickly locate the fault in a belt conveyor resulted in several hours of downtime for repairs, causing significant losses in coal production.

[0005] Traditional signal transmission methods for conveyor protection devices have several problems. Firstly, the signal transmission lines are complex, requiring the laying of numerous cables, which not only increases construction costs but also makes subsequent maintenance difficult. Secondly, signals are susceptible to electromagnetic interference and environmental noise during transmission, leading to signal distortion and loss, thus affecting the monitoring system's accurate assessment of equipment operating status. For example, in industrial environments with complex electromagnetic conditions, the stability and reliability of signal transmission are severely challenged, limiting the effective operation of the monitoring system and significantly reducing the accuracy of monitoring data, thus failing to provide a reliable basis for equipment maintenance and management. Summary of the Invention

[0006] The purpose of this invention is to provide an online monitoring method, device, equipment, and medium for conveyor protection devices to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides an online monitoring method for a conveyor protection device, the method comprising: The operating status parameters of the conveyor protection device are collected by a two-wire carrier address encoder, and the operating status parameters are converted into digital signals and then carrier modulated. During carrier modulation, frequency division multiplexing technology is used to distinguish the data channels corresponding to different address encoders, and a modulation signal containing device address identifier and status information is generated. DC power and the modulated signal are synchronously transmitted to the central processing unit via the same two-core cable; At the central processing unit, signal separation technology is used to extract the modulation signal and demodulate it to restore the status data corresponding to each address encoder. A database of the operating status of the conveyor protection device is established based on the restored status data, and the database is updated by a combination of polling detection and event triggering. When abnormal data is detected, an active reporting mechanism is activated to send alarm information to the monitoring terminal, and the location of the fault is determined based on the address encoder identifier.

[0008] Preferably, the abnormal status data includes at least one abnormal operating status parameter, and before initiating the active reporting mechanism to send alarm information to the monitoring terminal, it also includes: For each exception's running status parameters, a mapping relationship is found based on the exception's running status parameters to obtain the associated status parameters corresponding to the exception's running status parameters; If the associated status parameter corresponding to the abnormal operating status parameter is in a normal state, the abnormal operating status parameter is deleted from the abnormal status data, and the fault information of the sensor corresponding to the abnormal operating status parameter is added to the abnormal status data.

[0009] Preferably, if there are multiple abnormal operating status parameters corresponding to multiple device address identifiers, and these multiple abnormal operating status parameters belong to the same specified type, the method further includes the following before initiating the active reporting mechanism to send alarm information to the monitoring terminal: Sort the multiple device address identifiers according to the conveyor's conveying direction; The location corresponding to the device address identifier that is ranked first is determined as the fault location.

[0010] Preferably, the frequency division multiplexing technique used in the carrier modulation process to distinguish the data channels corresponding to different address encoders includes: allocating an independent carrier frequency band for each address encoder, wherein the carrier frequency band includes a center frequency and a frequency offset; mapping the digital signal sequence in the state parameter set to the corresponding carrier frequency band to generate a baseband signal; performing quadrature amplitude modulation processing on the baseband signal to generate a modulation signal containing in-phase and quadrature components; and performing frequency domain superposition of the modulation signals corresponding to different address encoders to generate a composite carrier signal.

[0011] Preferably, the synchronous transmission of DC power and the modulated signal through the same two-core cable includes: installing an impedance matching network at the beginning of the cable and adjusting the output impedance to match the characteristic impedance of the cable; using a coupler to superimpose the DC power and the composite carrier signal to generate a mixed signal; and synchronously transmitting the mixed signal through the same two-core cable.

[0012] Preferably, the step of extracting the modulated signal and demodulating it using signal separation technology includes: installing a high-pass filter at the end of the cable to filter out the DC component and extract the composite carrier signal; using a bandpass filter bank to separate the carrier frequency bands corresponding to different address encoders to obtain the modulated signal of each channel; performing quadrature demodulation processing on the modulated signal of each channel to recover the baseband signal; and performing timing synchronization and carrier phase recovery processing on the baseband signal to generate a reconstructed digital signal sequence.

[0013] Preferably, updating the operating status database using a combination of polling detection and event triggering includes: establishing a polling schedule table to sequentially query the status data of each address encoder at preset time intervals; setting an abnormal status threshold, and immediately triggering a data reporting process when any status parameter exceeds the corresponding threshold; periodically checking the event trigger flag during polling intervals, and interrupting the current polling task when the flag is valid, prioritizing the processing of abnormal status data.

[0014] Preferably, the activation of the active reporting mechanism to send alarm information to the monitoring terminal includes: constructing an alarm information frame structure, wherein the alarm information frame includes a start character, a device address field, an anomaly type code, a timestamp field, and a checksum; performing anti-interference encoding processing on the alarm information frame using differential encoding to generate an enhanced alarm signal; and sending the enhanced alarm signal to the monitoring terminal through a wireless communication module, while simultaneously storing alarm records in the local address encoder.

[0015] Preferably, the present invention further includes an online monitoring device for conveyor protection, the device comprising: The parameter acquisition module is used to collect the operating status parameters of the conveyor protection device through a two-wire carrier address encoder, convert the operating status parameters into digital signals, and then perform carrier modulation. The frequency division multiplexing module is used to distinguish the data channels corresponding to different address encoders during carrier modulation using frequency division multiplexing technology, and to generate a modulation signal containing device address identifier and status information; A cable transmission module is used to synchronously transmit DC power and the modulation signal to the central processing unit via the same two-core cable; The signal processing module is used to extract the modulated signal and demodulate it at the central processing unit using signal separation technology to restore the state data corresponding to each address encoder. The status management module is used to establish a conveyor protection device operation status database based on the restored status data, and to update the operation status database by combining polling detection and event triggering. The alarm reporting module is used to initiate an active reporting mechanism to send alarm information to the monitoring terminal when abnormal status data is detected, and at the same time determine the location of the fault based on the address encoder identifier.

[0016] Preferably, the present invention further includes an electronic device, comprising a processor and a memory, wherein the memory stores a computer program that, when executed by the processor, implements the steps of the above method.

[0017] Preferably, the present invention further includes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above method.

[0018] Compared with the prior art, the beneficial effects of the present invention are: The use of a two-wire carrier address encoder to collect operating status parameters of the conveyor protection device greatly simplifies the wiring structure. Traditional monitoring systems often require extensive and complex wiring, consuming significant manpower, resources, and time, and causing considerable inconvenience during maintenance. Furthermore, troubleshooting and repairing faults are extremely difficult. Now, with two-wire carrier technology, only a single two-core cable is needed to simultaneously transmit DC power and modulated signals. This simplifies and simplifies wiring, significantly reducing costs and mitigating the risk of failures caused by complex wiring. For example, in the upgrade of the conveyor monitoring system in a large mine, the adoption of two-wire carrier technology reduced wiring costs by approximately one-third, significantly improved system integration, made connections between devices more compact, and drastically reduced space requirements, facilitating subsequent equipment maintenance and upgrades.

[0019] Frequency division multiplexing (FDM) technology distinguishes the data channels corresponding to different address encoders, much like dividing a wide highway into different lanes, each with its own direction of travel and vehicle type, thus ensuring orderly and accurate data transmission. In traditional data transmission, data from different devices may interfere with each other, like vehicles sharing multiple lanes, easily causing traffic jams and accidents, leading to data confusion and loss, and affecting the monitoring system's accurate judgment of the conveyor's operating status. The application of FDM technology allocates a frequency range to each address encoder, and different data are transmitted in their respective frequency channels, effectively avoiding mutual interference between data, just like vehicles traveling in their own lanes without affecting each other. This ensures the accuracy and reliability of data transmission, enabling the monitoring system to obtain timely and accurate information on the operating status of the conveyor protection device.

[0020] Employing signal separation technology at the central processing unit is akin to accurately identifying the desired item from a jumbled pile of objects; it enables rapid extraction and demodulation of the modulated signal. This process restores the complexly modulated signal to the corresponding state data of each address encoder, significantly improving data processing efficiency. In previous technologies, signal processing was often cumbersome, requiring multiple complex steps and extensive calculations, consuming considerable time and computing resources. Now, with this advanced signal separation and demodulation technology, signals can be processed quickly and accurately, allowing the monitoring system to analyze and assess the operational status of the conveyor protection device in a shorter time, providing strong support for timely detection of potential problems. For example, in the conveyor monitoring of a factory, the data processing time was reduced by nearly half after adopting this technology, greatly improving the response speed of the monitoring system. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the working principle of the online monitoring method for the conveyor protection device described in this invention. Figure 2 A flowchart for distinguishing frequency division multiplexing data channels; Figure 3 This is a graph showing the performance analysis of signal transmission and processing. Figure 4 This is a monitoring graph for polling detection and event triggering. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figure 1 This invention provides an online monitoring method, device, equipment, and medium for a conveyor protection device. The method includes: acquiring the operating status parameters of the conveyor protection device through a two-wire carrier address encoder; converting the operating status parameters into digital signals and then performing carrier modulation; using frequency division multiplexing technology to distinguish the data channels corresponding to different address encoders during carrier modulation; generating a modulation signal containing device address identifiers and status information; synchronously transmitting DC power and the modulation signal to a central processing unit through the same two-core cable; extracting the modulation signal and performing demodulation processing at the central processing unit using signal separation technology to restore the status data corresponding to each address encoder; establishing a conveyor protection device operating status database based on the restored status data; updating the operating status database using a combination of polling detection and event triggering; and when abnormal status data is detected, initiating an active reporting mechanism to send alarm information to the monitoring terminal, while simultaneously determining the location of the fault based on the address encoder identifier.

[0024] Example 1: In practical implementation, considering that various operating status parameters of the conveyor do not exist in isolation, for example, conveyor belt misalignment can lead to uneven tension on both sides, resulting in local speed fluctuations; or, if the belt tension is too low, the belt will slip against the drive roller, causing the belt speed to drop abnormally, and at the same time, insufficient traction will increase the conveyor belt sag. Therefore, multiple sensors can be set up at the same detection position to detect multiple operating status parameters, and a mapping relationship between each operating status parameter can be established in advance. Based on this, for each abnormal operating status parameter, all related status parameters that are logically associated with it can be found in the above mapping relationship. For example, for the abnormal operating status parameter "belt tension too low", if the belt speed and conveyor belt sag at the same position are also abnormal operating status parameters, then the abnormal state of the above operating status parameter is determined; otherwise, if the belt speed and conveyor belt sag at the same position are not abnormal operating status parameters, it indicates that the tension sensor is faulty, causing a false alarm. In this case, the abnormal operating status parameter "belt tension too low" can be deleted from the abnormal status data, and the fault information of the tension sensor can be added to the abnormal status data. By verifying the aforementioned related parameters, false alarms caused by sensor malfunctions can be filtered out.

[0025] Furthermore, considering that abnormal states of operating parameters such as belt misalignment and abnormal material level usually propagate along the conveyor's conveying direction, for example, belt misalignment at the previous detection position can lead to subsequent misalignment in the downstream section, for the abnormal states of the above-mentioned types of parameters (which can be pre-set to specified types of parameters), the equipment address identifiers can be sorted according to the conveying direction to locate the first abnormal point in the sorted order, thereby locking the "source and starting point" of the fault propagation, eliminating subsequent secondary abnormal points affected by the fault, and achieving accurate location of the root cause of the fault.

[0026] Example 2: See Figure 2In practical implementation, frequency division multiplexing (FDM) technology is used during carrier modulation to distinguish the data channels corresponding to different address encoders. Allocating an independent carrier frequency band to each address encoder is the foundation of FDM technology. The determination of the carrier frequency band depends on the unique hardware identifier code of the address encoder. The hardware identifier code is an eight-bit binary number. The carrier frequency band includes two key parameters: center frequency and frequency offset. The formula for calculating the center frequency is the base frequency value plus the product of the hardware identifier code and the frequency interval step size. The base frequency value is set to 100 kHz, the frequency interval step size is set to 5 kHz, and the frequency offset is a fixed value set to 2 kHz. This means that the actual frequency range occupied by each address encoder is from the center frequency minus 2 kHz to the center frequency plus 2 kHz, with a total bandwidth of 4 kHz. In practice, the digital signal sequence in the state parameter set is mapped to the corresponding carrier frequency band. The mapping process is completed in the digital domain. The digital signal sequence is first fed into a digital upconversion chain for processing. The first step of the digital upconversion chain is to use an interpolation filter to increase the sampling rate of the digital signal sequence. The interpolation filter is implemented using a multi-stage cascaded half-band filter. The interpolation factor is determined according to the ratio of the final required sampling rate to the original sampling rate. The high sampling rate sequence after interpolation can reduce the design pressure of the subsequent analog reconstruction filter. Then, the high sampling rate digital sequence is multiplied with a digital carrier generated by a digitally controlled sine wave oscillator. The digital carrier oscillator is implemented by a direct digital frequency synthesizer. The frequency control word of the direct digital frequency synthesizer is calculated in real time according to the center frequency allocated to the address encoder. The result of the multiplication operation is the digital signal that shifts the baseband spectrum to the vicinity of the specified carrier frequency band.

[0027] In some embodiments, after generating the baseband signal, the baseband signal is subjected to quadrature amplitude modulation (QAM). QAM is a technique that combines two independent digital signals onto the same carrier. The QAM process first decomposes a high-speed binary digital signal sequence into two parallel low-speed signal sequences through a serial-to-parallel converter. These two signal sequences are called the in-phase component and the quadrature component, respectively. The in-phase component and the quadrature component are then waveform shaped by a pulse shaping filter. The pulse shaping filter is usually a square root raised cosine filter, and its roll-off factor is selected according to the channel bandwidth and symbol rate. The commonly used value of the roll-off factor is 0.35. The in-phase component and the quadrature component signals after pulse shaping are two baseband analog signals. Then, the in-phase component signal is multiplied by an in-phase carrier, and the quadrature component signal is multiplied by a quadrature carrier. The quadrature carrier and the in-phase carrier have the same frequency but are 90 degrees out of phase. Finally, the two multiplied signals are added together to generate a modulated signal containing the in-phase component and the quadrature component. In practical implementation, the modulation order of quadrature amplitude modulation can be 4QAM, 16QAM or 64QAM. The choice of modulation order needs to be balanced between spectral efficiency and noise immunity. When the channel conditions are good, a higher-order modulation such as 16QAM can be selected to improve the data rate. When the channel conditions are poor, a lower-order modulation such as 4QAM can be selected to ensure communication reliability. The switching of the modulation order can be dynamically completed by the control command issued by the central processing unit. After receiving the command, the address encoder changes the mapping rules and transmission parameters.

[0028] It is understandable that frequency domain superposition of the modulation signals corresponding to different address encoders generates a composite carrier signal. Frequency domain superposition is an efficient signal combining method. The frequency domain superposition operation is performed at the transmitting end of the central processing unit. The modulated signal generated by each address encoder is first upsampled to a uniform sampling rate. The upsampling process also uses an interpolation filter to prevent spectral aliasing. Then, a fast Fourier transform is performed on each upsampled signal to convert the time domain signal to the frequency domain, obtaining their respective discrete spectra. The discrete spectra of all address encoder signals are directly added at the frequency points to form a composite spectrum. The composite spectrum contains the frequency components of all channels. Finally, an inverse fast Fourier transform is performed on the composite spectrum to convert it back to the time domain, generating the final composite carrier signal. This digital frequency domain superposition method can precisely control the amplitude and phase of each channel signal, avoiding the nonlinear distortion and noise accumulation problems generated in the analog superposition process.

[0029] Optionally, carrier frequency band allocation can employ a dynamic allocation strategy. This strategy is centrally managed by the central processing unit (CPU). The CPU periodically monitors the channel noise level. If a carrier frequency band is found to be subject to persistent narrowband interference, the CPU can issue a reconfiguration command containing a new frequency allocation scheme. This dynamically switches the interfered address encoder to an idle carrier frequency band. This dynamic frequency allocation mechanism significantly improves the system's anti-interference capability and spectrum utilization. In practical implementation, the carrier generation circuit in quadrature amplitude modulation (QAM) processing needs to possess high frequency stability and phase noise performance. The carrier generation circuit uses a temperature-compensated crystal oscillator or a temperature-controlled crystal oscillator as the reference clock source. The frequency stability of the reference clock is typically better than one part per million. The reference clock is multiplied and synthesized using a phase-locked loop (PLL) circuit to generate the high-frequency carrier required for modulation. The in-phase and quadrature components of the carrier are generated by a digital phase splitter or a Hilbert converter. Strict orthogonality between the two carriers must be guaranteed, i.e., the phase difference must be precisely 90 degrees. Any quadrature error will cause image interference in the modulated signal, reducing demodulation performance.

[0030] In some embodiments, the design of the pulse shaping filter is a key factor affecting the signal spectrum and inter-symbol interference (ISI). The impulse response of the square root raised cosine filter crosses zero at all symbol times except the current symbol time. This characteristic can effectively eliminate ISI. The pulse shaping filter is implemented in the digital domain as a finite-length unit impulse response filter structure. The coefficients of the finite-length unit impulse response filter are calculated offline based on the designed roll-off factor and filter length and stored in read-only memory. The filter length is usually chosen to be six to eight times the symbol period to ensure sufficient time-domain truncation accuracy. Digital filtering operations are efficiently performed through a multiply-accumulator array. In practical implementation, the frequency domain superposition process places certain demands on the processor's computing power. The number of points in the Fast Fourier Transform (FFT) needs to cover the entire bandwidth of the composite signal. For example, if the system supports up to 32 address encoders, each occupying a 4 kHz bandwidth, the total bandwidth is approximately 128 kHz. According to the Nyquist sampling theorem, the sampling rate needs to be higher than 256 kHz. The number of points in the FFT is usually chosen to be an integer power of 2, such as 512 or 1024 points, to improve computational efficiency using fast algorithms. The superimposed composite carrier signal is converted into an analog signal by a digital-to-analog converter (DAC). The resolution of the DAC affects the signal-to-noise ratio of the output signal, and a 16-bit or higher resolution DAC is usually required.

[0031] It is understandable that, in order to further improve spectrum utilization, guard intervals can be set between adjacent carrier frequency bands. The width of the guard interval is determined based on the carrier frequency offset and possible Doppler shift. The guard interval can avoid adjacent channel interference caused by frequency drift or synchronization error. The guard interval is usually set to several hundred hertz to one thousand hertz. Although the existence of the guard interval reduces some spectrum efficiency, it improves the system robustness. In specific implementation, before the composite carrier signal is sent to the cable for transmission, it needs to be amplified by a power amplifier. The gain of the power amplifier is adjustable to adapt to the transmission loss of different cable lengths. The power amplifier needs to have good linearity to avoid introducing new harmonic distortion and intermodulation distortion that interfere with other channels. Class A or Class AB linear power amplifiers are usually used, and a bandpass filter is connected at the amplifier output to filter out out-of-band spurious emissions generated by the amplifier.

[0032] Example 3: In specific implementation, DC power and modulation signals are transmitted synchronously through the same two-core cable. Installing an impedance matching network at the beginning of the cable is the first step to ensure complete signal transmission. The impedance matching network adopts a passive LC network structure, specifically a π-type network, consisting of two parallel capacitors and one series inductor. The parameter values ​​of the network components are calculated based on the characteristic impedance of the cable and the frequency range of the transmitted signal. The characteristic impedance of the cable needs to be measured by a time-domain reflectometer. For commonly used shielded twisted-pair cables, the typical characteristic impedance is 100 ohms. The goal of the impedance matching network is to adjust the output impedance of the signal source to be as equal as possible to the characteristic impedance of the cable, thereby minimizing signal reflection at the beginning of the cable due to impedance discontinuity. The indicator for measuring the matching effect is the voltage standing wave ratio (VSWR). By adjusting the inductance and capacitance values, the VSWR can be controlled below 1.5, which means that most of the signal power can be effectively injected into the cable for transmission. In practical implementation, a coupler is used to superimpose the energy of the DC power supply and the composite carrier signal. The coupler is a key passive device containing two main paths: a DC path and an AC path. The DC path allows low-frequency DC power to pass through while blocking high-frequency carrier signals. The DC path is usually implemented by one or more chokes with large inductance values. The impedance of the choke to DC power is almost zero, but the impedance to high-frequency AC signals is very large. The AC path allows high-frequency composite carrier signals to pass through while blocking DC components. The AC path is composed of DC blocking capacitors. The DC blocking capacitors present infinite impedance to DC power, but very small impedance to high-frequency signals. The positive terminal of the DC power supply is connected to one end of the choke, and the composite carrier signal is connected to the same node through the DC blocking capacitor. The negative terminal of the DC power supply and the ground of the composite carrier signal share the same ground. In this way, a mixed signal containing both DC voltage and superimposed AC carrier signal is generated at the output of the coupler.

[0033] In practical implementation, a high-pass filter is installed at the cable end to filter out the DC component and extract the composite carrier signal. The cable end refers to the input interface of the address encoder or central processing unit. The high-pass filter is usually a first-order or second-order passive RC filter or LC filter. For a first-order RC high-pass filter, the formula for calculating its cutoff frequency is:

[0034] Where: symbol Represents the cutoff frequency of a high-pass filter, symbol Represents the resistance value of the resistor element in the filter, symbol This represents the capacitance value of the capacitor element in the filter.

[0035] The cutoff frequency must be set below the lowest frequency component of the composite carrier signal. For example, if the lowest frequency of the carrier signal is 98 kHz, then the cutoff frequency can be set to 50 kHz. This way, the DC and very low frequency components below 50 kHz are significantly attenuated, while the carrier signal above 98 kHz can pass through with almost no attenuation. In practical implementation, a bandpass filter bank is used to separate the carrier frequency bands corresponding to different address encoders. The bandpass filter bank is composed of multiple bandpass filters with different center frequencies connected in parallel. The center frequency of each bandpass filter precisely corresponds to the center frequency of the carrier frequency band allocated to an address encoder. The bandwidth of each bandpass filter is slightly larger than the actual bandwidth of the address encoder signal. For example, if each address encoder occupies a 4 kHz bandwidth, then the 3 dB bandwidth of the corresponding bandpass filter can be set to 5 kHz. The bandpass filters can be integrated surface acoustic wave filters or ceramic filters. These filters have the advantages of good rectangular coefficient and high stability. The mixed composite carrier signal is simultaneously sent to the input of all parallel bandpass filters. Each bandpass filter only allows narrowband signals with a center frequency close to its own to pass through, thereby separating the modulation signals belonging to different address encoders and obtaining the modulation signals of each channel.

[0036] It is understandable that quadrature demodulation is performed on the modulated signal of each channel to recover the baseband signal. Quadrature demodulation is the reverse process of quadrature amplitude modulation. Quadrature demodulation requires the generation of two local carrier signals. One is in phase and frequency with the in-phase carrier of the transmitter, called the in-phase carrier. The other is in phase and frequency with the quadrature carrier of the transmitter, called the quadrature carrier. These two local carriers are generated by a local oscillator through a digital phase splitter. The separated modulated signals are multiplied by the in-phase carrier and the quadrature carrier, respectively. The multiplication operation is usually implemented by an analog multiplier or a digital mixer. The result of the multiplication operation outputs two signals. One contains the baseband in-phase component and the second harmonic component. The other contains the baseband quadrature component and the second harmonic component. These two signals are then passed through a low-pass filter. The low-pass filter removes the high-frequency second harmonic component and retains only the low-frequency baseband in-phase component and the baseband quadrature component signal. In this way, the original two baseband signals are recovered. In practical implementation, the baseband signal undergoes timing synchronization and carrier phase recovery processing to generate a reconstructed digital signal sequence. The purpose of timing synchronization is to find the optimal sampling time to minimize inter-symbol interference. Timing synchronization typically employs an early-late gate synchronization algorithm, which adjusts the sampling clock phase by comparing the signal energy of two points before and after the current symbol time, ensuring that the sampling point is always located at the center of the symbol period. The purpose of carrier phase recovery is to compensate for the phase difference between the transmitting end carrier and the receiving end local carrier. Carrier phase recovery can be implemented using a Costas ring, a phase-locked loop. It uses a phase detector to detect the phase error between the in-phase and quadrature components and uses this error signal to fine-tune the phase of the local oscillator until the phase error is zero. After timing synchronization and carrier phase recovery, the in-phase and quadrature baseband signals are sampled and decided at the correct time, converting the analog signal back into a digital signal sequence, i.e., the reconstructed digital signal sequence.

[0037] Optionally, the impedance matching network can employ active circuitry to achieve adaptive matching. Active impedance matching networks dynamically adjust the parameters of variable capacitors or inductors in the network by detecting the reflected wave power at the cable's origin, ensuring the network always operates in optimal matching condition. This adaptive matching can compensate for impedance changes caused by cable aging, temperature variations, or connector oxidation, further improving the stability of long-distance transmission. In practical implementation, the individual filters of the bandpass filter bank can be integrated into a monolithic crystal filter or surface acoustic wave filter array. This integrated design helps reduce size, improve consistency, and lower production costs. The center frequency of each filter is precisely controlled during manufacturing using photolithography, resulting in high temperature stability and long-term reliability. Quadrature demodulation can also be performed in the digital domain. The filtered modulated signal is first digitized using a high-speed, high-resolution analog-to-digital converter, and then digital down-conversion technology and digital filters are used in a digital signal processor or field-programmable gate array to achieve all functions such as quadrature demodulation, timing synchronization, and carrier phase recovery. Fully digital demodulation schemes offer advantages such as high flexibility, good consistency, and ease of upgrading, but also place higher demands on the processor's computing power.

[0038] See Figure 3 This paper showcases the key performance indicators of signal transmission and processing in a conveyor protection system. The figure includes frequency response curves for multiple technical parameters such as voltage standing wave ratio (VSWR), signal power, impedance matching quality, transmission efficiency, and filter response. These data reflect the effectiveness of the impedance matching network and coupler in ensuring signal integrity during the synchronous transmission of DC power and modulated signals through a two-core cable. The graphs clearly show the trends of various performance indicators across different frequency ranges. In particular, the filter response curves demonstrate the high-pass filter's effectiveness in filtering DC components and its transmission characteristics for carrier signals, providing a visual basis for evaluating the effectiveness of signal separation techniques.

[0039] Example 4: In specific implementation, a combination of polling detection and event triggering is used to update the operating status database. Establishing a polling schedule table is the foundation for achieving ordered queries. The polling schedule table is a data structure stored in the non-volatile memory of the central processing unit, such as EEPROM or Flash memory. The polling schedule table contains multiple fields used to manage periodic access to all address encoders in the system. The core fields of the polling schedule table include the address encoder identifier, query interval, last successful query timestamp, and current status flag. The address encoder identifier is a unique number for each address encoder, usually two bytes long. The query interval defines the period at which the central processing unit sends status query instructions to the address encoder, and its value is set according to the importance and parameter change rate of the protection device associated with the address encoder. The last successful query timestamp records the time point when the status data was last correctly received from the address encoder, in Unix timestamp format, accurate to milliseconds. The current status flag is used to indicate the online status of the address encoder, whether the communication has timed out, or whether there is an unconfirmed anomaly. The status data of each address encoder is queried sequentially at preset time intervals. The central processing unit (CPU) runs a real-time task scheduler that maintains a high-precision system clock driven by a highly stable crystal oscillator. The task scheduler periodically scans each entry in the polling schedule table, calculating the difference between the current time and the timestamp of the last successful query. When the difference is greater than or equal to the preset query time interval, the task scheduler adds the query task for that address encoder to the ready queue. During query execution, the CPU sends a query command frame to the target address encoder via a carrier communication module. This frame contains the identifier of the target address encoder and the command code. Upon receiving a query command for its own address, the address encoder packages the currently collected status parameters into a response data frame and sends it back to the CPU via a carrier signal. Upon receiving the response, the CPU parses the data frame, extracts the valid status parameters, updates the corresponding record in the running status database with the new data, and simultaneously updates the timestamp of the last successful query in the polling schedule table to the current time.

[0040] Abnormal state thresholds are set as limit values ​​for different monitoring parameters. These thresholds are pre-stored in the configuration database of the central processing unit. The abnormal state thresholds are set according to the technical specifications and safe operation requirements of the conveyor protection device. For example, for motor operating current, the abnormal state threshold may be set as 110% of the rated current as the warning threshold and 150% of the rated current as the alarm threshold. For bearing temperature, the abnormal state threshold may be set to different levels such as 70 degrees Celsius and 90 degrees Celsius according to the insulation class of the bearing. The voltage fluctuation threshold may be set to multiple levels such as ±10% and ±15% of the rated voltage. When any status parameter is detected to exceed the corresponding threshold, the data reporting process is immediately triggered. The detection process occurs after the central processing unit parses the status data returned by the address encoder. The central processing unit compares the received parameters such as current, voltage, and temperature with the corresponding abnormal status thresholds preset in the configuration database. If a parameter value exceeds the abnormal status threshold it is set for, it means that an abnormal or potential fault state has been detected. At this time, the normal polling process will be interrupted, and the central processing unit will immediately start a high-priority data reporting process. The data reporting process includes sending an emergency read command to the address encoder, requesting the address encoder to report more detailed data snapshots, such as waveform data with a higher sampling rate or multiple consecutive historical data points. At the same time, the central processing unit will set an abnormal event flag for the address encoder in the running status database and record the precise time of the abnormality, the type of abnormal parameter, and the specific value exceeding the threshold.

[0041] Referring to Table 1, the event trigger flags are periodically checked during the polling intervals. The event trigger flags are one or more binary bits located in the central processing unit memory or special function registers. Each address encoder can be associated with an independent event trigger flag, or each type of abnormal event (such as overcurrent, overvoltage, overheating) can have an independent event trigger flag. The checking of the event trigger flags is performed by a high-frequency background task or hardware interrupt service routine. The running cycle of this checking task is much shorter than the shortest polling interval, for example, all event trigger flags may be checked once every 10 milliseconds. The checking process is implemented by reading the status of the flag register. When the flag is valid, the current polling task is interrupted, and abnormal state data is processed first. The event trigger flag is usually set by the hardware comparator circuit or the threshold comparison logic in the software at the moment when the parameter exceeds the limit. When the periodic check task finds that an event trigger flag changes from "0" to "1" (valid state), the check task will immediately send an interrupt request to the scheduler of the real-time operating system. After receiving the interrupt request, if a low-priority polling task is currently being executed, the scheduler will save the context of the current polling task (such as the program counter and register values), then suspend the polling task and schedule a high-priority event handling task instead. This event handling task will first determine which address encoder or what type of abnormal event triggered the flag, and then execute the corresponding emergency handling logic, such as quickly reading the detailed data of the address encoder, updating the alarm record in the running status database, and preparing to send alarm information to the host computer monitoring system. After completing the high-priority event handling, the scheduler will resume the previously interrupted polling task and continue the polling sequence from the interrupted address encoder.

[0042] It is understandable that the maintenance of the polling schedule table is dynamic. When a new address encoder is added to the system, the central processing unit identifies the new node through a preset node discovery protocol and automatically creates a new record in the polling schedule table, assigns an unused address encoder identifier, and sets a default query interval. Similarly, if an address encoder fails to respond to query commands multiple times consecutively, its status flag in the polling schedule table will be marked as "communication timeout" or "offline." The system may then attempt to reduce its query frequency or trigger a device fault alarm. In specific implementations, the setting of abnormal status thresholds can be hierarchical. For example, setting two levels: a warning threshold and an alarm threshold. When a parameter exceeds the warning threshold but does not reach the alarm threshold, the system may simply record the event in the running status database and send a low-priority notification message to the host computer. However, when the parameter exceeds the alarm threshold, the entire emergency data reporting and alarm process described above is immediately triggered. This hierarchical processing mechanism helps to distinguish between different degrees of abnormality and avoids overreacting to minor fluctuations.

[0043] Table 1: Polling Schedule Table

[0044] Optionally, the setting mechanism of the event trigger flag can have different sensitivities. For example, it can be set to set the flag only when the parameter exceeds the threshold for a certain period of time (e.g., 100 milliseconds). This short delay can effectively filter out occasional transient pulse interference and prevent false alarms. The logic for judging the duration can be implemented by a software timer. The timer is started when the parameter exceeds the limit for the first time. If the parameter still exceeds the limit after the timer expires, the event trigger flag is set. If the parameter returns to the normal range before the timer expires, the timer is reset, and the flag remains unchanged. In some embodiments, the interrupt management of the polling task can adopt a nested interrupt model. That is, if a higher-priority event processing task occurs during execution (e.g., multiple address encoders simultaneously report serious faults), the current event processing task itself can be temporarily interrupted and the higher-priority event can be processed instead. This nested interrupt mechanism ensures that the system can respond to multiple fault events in extreme cases. After each interrupted task is completed, the system will return to the previous interrupted task to continue execution until it finally returns to the initially interrupted polling task.

[0045] In practical implementation, after the high-priority task of processing abnormal state data is completed, the event trigger flag needs to be reset to ensure that the same abnormal event is not processed repeatedly. The reset operation is usually performed after confirming that the relevant data for the abnormal event has been completely recorded and that necessary alarm information has been sent to the host computer. Resetting can be achieved by writing a value to the flag register via software. If the flag is set by hardware circuitry, it may be necessary to send a clear command to the hardware circuitry via software to reset the flag. It can be understood that the combination of polling detection and event triggering effectively balances the system's resource usage and response speed to abnormal events. During most normal operating periods, the system performs periodic status checks with low power consumption and computational load, maintaining the update of the operating status database. Once an abnormality occurs, the system can immediately interrupt regular tasks to capture and respond to the abnormality as quickly as possible. This design is particularly suitable for industrial monitoring scenarios that require long-term stable operation and have strict requirements for fault response time.

[0046] Optionally, the polling scheduler structure can be further expanded by adding fields such as "communication failure count" and "retry count" for more granular management of communication reliability. For example, when an address encoder fails to respond after three consecutive queries, the system can automatically mark it as faulty and stop subsequent polling attempts until maintenance personnel intervene or the device comes back online. This avoids the continuous consumption of system resources on nodes that cannot communicate. In practical implementation, the priority of tasks that periodically check event trigger flags needs to be set higher than that of ordinary polling tasks, but lower than that of certain critical hardware interrupts (such as watchdog timer interrupts) to ensure that events can be responded to in a timely manner without affecting the stability of the entire system. The task cycle needs to be carefully selected based on the fastest changing time constant of the monitored physical process to ensure that rapid abnormal events can be captured while avoiding excessive processor load due to overly frequent checks.

[0047] See Figure 4 This chart displays current monitoring data from multiple conveyor protection devices over a continuous period, encompassing the complete process of normal operation, early warning, and alarm states. It clearly reflects the effectiveness of the polling scheduling system's query of encoder status data at preset time intervals. The marked early warning and alarm thresholds provide clear standards for judging equipment operating status, while the specially marked event trigger points demonstrate the system's immediate data reporting response when monitored parameters exceed corresponding thresholds. This visualization helps explain the advantages of combining polling detection with event triggering in balancing system resource utilization and abnormal event response speed.

[0048] Example 5: In specific implementation, when abnormal status data is detected, an active reporting mechanism is initiated to send alarm information to the monitoring terminal. Constructing an alarm information frame structure is the foundation for reliable information transmission. The alarm information frame includes a start character, a device address field, an anomaly type code, a timestamp field, and a checksum. The start character is a fixed hexadecimal value sequence 0xAA55, occupying two bytes. The start character is used for frame synchronization by the receiver. When the receiving program of the monitoring terminal detects consecutive 0xAA and 0x55 in the data stream, it considers a valid alarm information frame to have started. The device address field is two bytes long and is used to store the unique identifier of the address encoder that triggered the alarm, for example, address encoder number 0x000A. The anomaly type code occupies one byte, and each bit or each bit of the code... The code value corresponds to a specific anomaly type. For example, the lower four bits of this byte can be used to encode the parameter type (e.g., 0001 represents current, 0010 represents voltage, and 0011 represents temperature), and the higher four bits can be used to encode the anomaly level (e.g., 0001 represents warning, 0010 represents alarm, and 1111 represents emergency danger). The timestamp field is four bytes long and stores the Unix timestamp of the time when the anomaly occurred, with precision to the second. For example, the value 1640995200 represents January 1, 2022, 00:00:00. The checksum is calculated using the Cyclic Redundancy Check algorithm, selecting the CRC-16-CCITT standard, with a generator polynomial of 0x1021. The checksum calculation covers all bytes from the start character to the timestamp field and is used to verify the integrity of the alarm information frame after transmission. Suppose that address encoder 0x000A (corresponding to a tear detection device) detects that the vibration parameter exceeds the limit. At this time, the microprocessor of address encoder 0x000A will construct an alarm information frame. The start character is fixed at 0xAA55, the device address field is filled with 0x000A, the anomaly type code is set to 0x23 according to the severity of the vibration exceeding the limit (indicating vibration parameter and alarm level), the timestamp field is filled with the Unix timestamp of the time when the anomaly was detected, and finally the CRC-16 check code of all the preceding bytes is calculated and filled into the check code field.

[0049] Differential coding is used to perform anti-interference encoding on alarm information frames to generate enhanced alarm signals. Differential coding is an encoding method that represents data through changes in signal level rather than absolute level. The specific encoding rule is as follows: each data bit is XORed with the previous encoded bit, and the result is used as the bit actually transmitted on the line. At the beginning of encoding, a virtual reference bit is needed, usually set to 0. For example, for the first data byte 0xAA (binary 10101010) in the alarm information frame, the differential encoding process is as follows: the initial reference bit is 0; the first data bit 1 is XORed with the reference bit 0 to obtain the transmitted bit 1, at which point the reference bit is updated to the current data bit 1; the second data bit 0 is XORed with the reference bit 1 to obtain the transmitted bit 1, and the reference bit is updated to 0; the third data bit XORed with the reference bit 1... XORing bit 1 with reference bit 0 yields transmitted bit 1, and the reference bit is updated to 1; this process continues. The advantage of differential encoding is that even if signal phase inversion occurs during transmission, the decoder can still correctly recover the original data because the decoder focuses on whether adjacent bits have changed, rather than the absolute polarity of the level. To further improve clock recovery and DC balance, Manchester encoding can be applied to the differentially encoded bitstream. Manchester encoding divides each bit cycle into two halves. When the transmitted bit is 1, the level is high in the first half of the cycle and low in the second half; when the transmitted bit is 0, the level is low in the first half of the cycle and high in the second half. Manchester encoding ensures that there is one level transition within each bit cycle, making it easier for the receiver to extract the synchronization clock. The signal processed by differential encoding and Manchester encoding is the enhanced alarm signal.

[0050] Enhanced alarm signals are sent to the monitoring terminal via a wireless communication module, which can be a GPRS module, a LoRa module, or a 4GCat.1 module. After receiving the data packet, the monitoring terminal will reply with an acknowledgment signal. If the sending end does not receive an acknowledgment within a set time, a retransmission mechanism will be triggered. At the same time, alarm records are stored in the address encoder. The alarm records are stored in the non-volatile memory inside the address encoder, such as a serial Flash memory. The format of the stored alarm records is basically the same as that of the alarm information frame, but may contain more detailed information, such as the instantaneous values ​​of abnormal parameters, historical data snapshots for a period of time before the anomaly occurred, etc. The storage space is usually designed as a circular buffer. When the memory is full, the latest alarm record will overwrite the oldest alarm record.

[0051] In some embodiments, the anomaly type code of the alarm information frame can be designed to be more refined. For example, two bytes can be used to represent the anomaly information. The high four bits of the first byte represent the device category, and the low four bits represent the specific device subcategory. The high four bits of the second byte represent the anomaly severity level, and the low four bits represent the specific anomaly cause code. This more detailed encoding facilitates the monitoring terminal software to accurately identify the source and nature of the alarm and execute corresponding processing strategies. In specific implementations, the initial reference bit state of differential encoding needs to be agreed upon in advance by the sending and receiving ends, usually agreed to be logic 0. If the receiving end mistakenly interprets the initial state as logic 1, it will lead to an error in the decoding of the entire data frame. To solve this problem, a preamble can be added before the start symbol of the alarm information frame. The preamble consists of a fixed alternating bit pattern of 01010101. The receiving end uses the preamble for bit synchronization and automatically corrects the initial reference state to ensure the correct start of differential decoding.

[0052] In practical implementation, the alarm records can be stored and managed using a wear leveling algorithm in the local address encoder. Since each storage cell of a non-volatile memory has a limited number of erase and write cycles, the wear leveling algorithm dynamically maps logical addresses to physical addresses, so that write operations are evenly distributed throughout the entire memory space, preventing certain specific cells from being written to failure prematurely, thereby extending the lifespan of the memory. When it is necessary to read historical alarm records, the microprocessor will traverse the valid records in the memory, sort them according to time order, and output them.

[0053] It is understandable that after receiving alarm information, the monitoring terminal, in addition to providing audible and visual alerts and displaying information on the interface, can automatically associate the alarm information with the pre-set processing procedures in the contingency plan library based on the device address field and anomaly type code in the alarm information frame. For example, when a critical alarm information is received from address encoder 0x000A (tear detection), the monitoring software can automatically display the emergency shutdown operation procedure for that conveyor section and prompt the nearest maintenance personnel to be contacted. This intelligent linkage between alarm information and contingency plans can significantly improve the efficiency of emergency response to faults. In specific implementation, the transmission priority of enhanced alarm signals can be higher than that of normal polling status data. In the central processing unit or communication gateway, the data transmission queue can be set as a priority queue. When alarm information needs to be sent, even if there are already normal status data packets waiting to be sent in the queue, the alarm information packet will be inserted at the front of the queue and sent with priority. This priority scheduling mechanism ensures low-latency transmission of alarm information.

[0054] Optionally, the non-volatile storage of alarm records can employ a file system with power-loss protection, such as a small embedded file system. This file system can manage multiple alarm record files, each containing several records, and maintain a file allocation table. This file system approach facilitates time-based querying, exporting, and deleting of alarm records, and is easier to maintain and use than a simple circular buffer. In some embodiments, to cope with communication interruptions in extreme cases, alarm information can be buffered locally with a validity period. If communication is restored within the validity period, the buffered alarm information will be retransmitted. If communication is not restored after the validity period, the system may attempt to use a backup channel or trigger a higher-level local audible and visual alarm to ensure that fault information is not missed. In specific implementations, checksum calculation can be performed using hardware accelerators. For example, some microcontrollers have a built-in CRC calculation unit. The data block of the alarm information frame can be directly sent to the CRC unit for calculation via DMA, and the calculation result is automatically stored in a designated register. Compared with software lookup table methods for calculating CRC checksums, this method is faster and does not consume CPU resources, which is beneficial to improving the real-time performance of the system.

[0055] Optionally, the start symbol 0xAA55 of the alarm information frame can be replaced with other sequences with good autocorrelation characteristics, such as 0x55AA or a longer Barker code sequence. Longer synchronization sequences can improve the reliability of frame synchronization in noisy environments, but they also increase the overhead of each frame's data, requiring a balance between reliability and efficiency. In practical implementation, power management of the wireless communication module is a crucial consideration. For battery-powered address encoders, the wireless communication module should be in deep sleep mode most of the time to conserve power. When an alarm event needs to be reported, the microprocessor triggers a wake-up signal for the wireless communication module via a GPIO pin. After being woken up, the wireless communication module quickly establishes a connection and sends data. After data transmission is complete, it immediately re-enters sleep mode. This operating mode can significantly extend battery life.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A conveyor protection device online monitoring method, characterized by, The method is realized by the following technical solutions: The running state parameters of the conveyor protection device are collected by a two-wire carrier address encoder, and the running state parameters are converted into digital signals and then carrier modulated; In the carrier modulation process, frequency division multiplexing technology is used to distinguish the data channels corresponding to different address encoders to generate a modulation signal containing device address identification and state information; The direct current power supply and the modulation signal are synchronously transmitted to the central processing unit through the same two-core cable; The modulation signal is extracted by signal separation technology at the central processing unit end and demodulated to restore the state data corresponding to each address encoder; A conveyor protection device running state database is established according to the restored state data, and the running state database is updated in a combination of polling detection and event triggering; When abnormal state data is detected, an active reporting mechanism is started to send alarm information to the monitoring terminal, and the fault location is determined according to the address encoder identification.

2. The method of online monitoring of a conveyor protection device according to claim 1, characterized in that, The abnormal state data includes at least one abnormal running state parameter, and before starting the active reporting mechanism to send alarm information to the monitoring terminal, it also includes: For each abnormal running state parameter, the associated state parameter corresponding to the abnormal running state parameter is obtained by searching the mapping relationship based on the abnormal running state parameter; If the associated state parameter corresponding to the abnormal running state parameter is a normal state, the abnormal running state parameter is deleted from the abnormal state data, and the fault information of the sensor corresponding to the abnormal running state parameter is added to the abnormal state data.

3. A conveyor guard online monitoring method as claimed in claim 2, wherein, If there are multiple abnormal running state parameters corresponding to multiple device address identifications, the multiple abnormal running state parameters belong to the same specified type of parameters, and before starting the active reporting mechanism to send alarm information to the monitoring terminal, it also includes: Sort the multiple device address identifications according to the conveying direction of the conveyor; The position corresponding to the first device address identification is determined as the fault position.

4. The method of on-line monitoring of a conveyor protection device according to claim 1, characterized in that, The frequency division multiplexing technology used in the carrier modulation process to distinguish the data channels corresponding to different address encoders includes: allocating an independent carrier frequency segment to each address encoder, and the carrier frequency segment contains a center frequency and a frequency offset; Map the digital signal sequence in the state parameter set to the corresponding carrier frequency segment to generate a baseband signal; The baseband signal is quadrature amplitude modulated to generate a modulation signal containing in-phase and quadrature components; The modulation signals corresponding to different address encoders are frequency domain superimposed to generate a composite carrier signal; The synchronous transmission of the direct current power supply and the modulation signal through the same two-core cable includes: An impedance matching network is installed at the beginning of the cable to adjust the output impedance to match the cable characteristic impedance; A coupler is used to superimpose the direct current power supply and the composite carrier signal to generate a mixed signal; The mixed signal is synchronously transmitted through the same two-core cable.

5. A conveyor guard online monitoring method as claimed in claim 4, wherein, The signal separation technology is used to extract the modulation signal and perform demodulation processing, which includes installing a high-pass filter at the end of the cable to filter out the direct current component and extract the composite carrier signal; The carrier frequency bands corresponding to different address encoders are separated by a band-pass filter to obtain modulation signals of each channel; The modulation signals of each channel are subjected to quadrature demodulation processing to recover baseband signals; The baseband signals are subjected to timing synchronization and carrier phase recovery processing to generate reconstructed digital signal sequences.

6. The method of online monitoring of a conveyor protection device of claim 1, wherein, The updating of the running state database by the combination of polling detection and event triggering comprises: A polling schedule table is established to sequentially query the state data of each address encoder at preset time intervals; An abnormal state threshold is set, and when any state parameter is detected to exceed the corresponding threshold, the data reporting process is triggered immediately; Event trigger flags are checked periodically during the polling gap, and when the flags are valid, the current polling task is interrupted and the abnormal state data is processed preferentially.

7. The method of on-line monitoring of a conveyor protection device according to claim 1, characterized in that, The sending of alarm information to the monitoring terminal by the active reporting mechanism comprises: An alarm information frame structure is constructed, and the alarm information frame contains a start symbol, a device address field, an abnormal type code, a timestamp field and a check code; A differential encoding method is used to perform anti-interference encoding processing on the alarm information frame to generate an enhanced alarm signal; The enhanced alarm signal is sent to the monitoring terminal through a wireless communication module, and alarm records are stored in the address encoder.

8. Conveyor protection device online monitoring device, characterized in that The device comprises: A parameter acquisition module is configured to collect running state parameters of the conveyor protection device by the two-wire carrier address encoder, and to convert the running state parameters into digital signals and then perform carrier modulation; A frequency division multiplexing module is configured to distinguish data channels corresponding to different address encoders by using frequency division multiplexing technology during carrier modulation to generate modulation signals containing device address identifiers and state information; A cable transmission module is configured to synchronously transmit a direct current power supply and the modulation signals to a central processing unit through the same two-core cable; A signal processing module is configured to extract the modulation signals and perform demodulation processing at the central processing unit end to restore state data corresponding to each address encoder; A state management module is configured to establish a running state database of the conveyor protection device according to the restored state data, and to update the running state database by the combination of polling detection and event triggering; An alarm reporting module is configured to start an active reporting mechanism to send alarm information to the monitoring terminal when abnormal state data is detected, and to determine the location of the fault occurrence according to the address encoder identifier.

9. An electronic device, comprising: The device comprises a processor and a memory, and the memory stores a computer program which, when executed by the processor, implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program which, when executed by the processor, implements the steps of the method according to any one of claims 1 to 7.

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