Smoke monitoring signal anti-interference transmission system in high magnetic field area of aluminum smelting

Abstract

The application discloses an aluminum smelting high magnetic field area flue gas monitoring signal anti-interference transmission system, which comprises a signal acquisition module, a signal filtering module, a signal correction module and a signal transmission module, relates to the aluminum smelting high magnetic field area flue gas monitoring technical field, and effectively filters out electromagnetic interference in the aluminum smelting high magnetic field area through the combination design of time domain low-pass filtering and frequency domain band-pass filtering of the signal filtering module and the dynamic parameter adjustment mechanism. Meanwhile, the signal correction module corrects error data through trend analysis and CRC check, eliminates distortion components caused by electromagnetic interference through spectrum analysis and band-stop filtering, significantly improves the accuracy and integrity of the flue gas monitoring signal, alleviates the problem that noise, error and distortion in the original signal affect the monitoring precision, and realizes the anti-interference of signal transmission through the hierarchical marking and path adaptation design of the signal transmission module.

Description

Technical Field

[0001] This invention relates to the field of flue gas monitoring technology in high magnetic field areas of aluminum smelting, and particularly to an anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting. Background Technology

[0002] During flue gas monitoring in the high magnetic field zone of aluminum smelting, the original flue gas parameter signals are easily affected by low-frequency interference and high-frequency noise due to the strong electromagnetic interference generated by the high magnetic field of the electrolytic cell and high-voltage electrical appliances such as rectifier transformers in the production environment, resulting in a large amount of noise components mixed into the signal.

[0003] Currently, the following problems exist in signal transmission: 1. In the existing technology, signal filtering mostly adopts low-pass or band-pass filtering with fixed parameters, which is difficult to adapt to the time-varying interference characteristics in aluminum smelting scenarios and has limited filtering effect. At the same time, the signal after preliminary filtering may still have data errors and signal distortion caused by electromagnetic interference, which further affects the signal quality.

[0004] 2. In the signal transmission stage, the existing technology does not match the appropriate transmission path for signals of different quality. High-quality signals may have reduced transmission efficiency due to high transmission path delay and high packet loss rate. Signals that are susceptible to interference may have transmission errors due to insufficient anti-interference capability of the path. As a result, the overall transmission reliability of the monitoring signal is difficult to guarantee, and it cannot meet the stability requirements of flue gas monitoring in the high magnetic field area of ​​aluminum smelting. Summary of the Invention

[0005] To address the technical problems existing in the background art, this invention proposes an anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting.

[0006] The anti-interference transmission system for monitoring flue gas signals in high magnetic field areas of aluminum smelting proposed in this invention includes: Signal acquisition module: In the high magnetic field area of ​​aluminum smelting, raw signals of flue gas parameters are acquired through sensors; The original signal contains noise caused by electromagnetic interference generated by the high magnetic field of the electrolytic cell and high-voltage electrical appliances such as rectifier transformers during the aluminum smelting process. The sensors used to collect raw signals of flue gas parameters include: a laser scattering sensor for collecting particulate matter concentration in flue gas, an electrochemical sensor for collecting harmful gas concentration in flue gas, and a thermocouple sensor for collecting flue gas temperature. Signal filtering module: performs low-pass filtering of the time domain signal and band-pass filtering of the frequency domain signal on the raw flue gas parameter signal to remove high-frequency noise and low-frequency interference in the signal and obtain a preliminary filtered signal; Signal correction module: For the initial filtered signal, detect and correct the errors in the initial filtered signal, detect and remove the distortions in the initial filtered signal, and form a corrected signal; Signal transmission module: Marks the correction signal, indicating whether it is high-quality transmission or anti-interference transmission; obtains a set of preset transmission paths, and divides the preset transmission paths in the set into high-quality transmission paths and anti-interference transmission paths; correction signals marked as high-quality transmission are transmitted through the high-quality transmission path, and correction signals marked as anti-interference transmission are transmitted through the anti-interference transmission path.

[0007] Preferably, in the signal filtering module, the original flue gas parameter signal is subjected to low-pass filtering in the time domain and band-pass filtering in the frequency domain to obtain a preliminary filtered signal, including the following steps: The time-domain components of the original flue gas parameter signal are extracted, and a low-pass filter is used to perform a low-pass filter operation to obtain the effective time-domain signal, filtering out the low-frequency interference caused by the power frequency magnetic field in the time-domain components; Fourier transform is applied to the original flue gas parameter signal to obtain the frequency domain components of the original flue gas parameter signal; A bandpass filter is used to perform a bandpass filtering operation to obtain the effective signal in the frequency domain; high-frequency noise caused by inverter harmonics is filtered out from the frequency domain components. The effective signal in the frequency domain is converted into a time domain signal form through inverse Fourier transform, and then combined with the effective signal in the time domain to form a preliminary filtered signal.

[0008] Preferably, in the signal filtering module, the cutoff frequency parameter of the low-pass filter and the passband range parameter of the band-pass filter are generated in the following manner: Obtain the smelting filter parameter library, which includes the cutoff frequency parameters of low-pass filters and the passband range parameters of band-pass filters under multiple interference scenarios. Real-time interference features of the original flue gas parameter signals are extracted. The real-time interference features include the frequency peak value and amplitude variation period of the interference signal. The cosine similarity algorithm is used to obtain the similarity matching between the real-time interference features and multiple interference scenarios in the smelting filter parameter library. The interference scenario with the highest similarity is selected as the matching scenario. Extract the cutoff frequency parameters of the low-pass filter and the passband range parameters of the band-pass filter corresponding to the suitable scenario from the smelting filter parameter library, and use them as the cutoff frequency parameters of the low-pass filter and the passband range parameters of the band-pass filter.

[0009] Preferably, in the signal correction module, detecting and correcting errors in the preliminary filtered signal includes the following steps: The data acquisition card extracts continuous data points of the preliminary filtered signal in the time series, and arranges them in the order of acquisition time to form a time-domain signal sequence. A trend analysis algorithm is used to generate a trend line for the time-domain signal sequence. Based on a preset deviation range, data points in the time-domain signal sequence that exceed the preset deviation range are identified as abnormal data points in the trend line of the time-domain signal sequence. The CRC check algorithm is used to perform data consistency verification on abnormal data points. Abnormal data points that fail the CRC check are regarded as error data points. The error data points are corrected by using linear interpolation to replace the original error data points.

[0010] Preferably, in the signal correction module, detecting and correcting distortion in the preliminary filtered signal includes the following steps: The pre-filtered signal is subjected to spectrum analysis using a spectrum analyzer to obtain the frequency distribution characteristics of the signal. Frequency distribution characteristics include peak frequency and frequency band percentage; The difference between the frequency distribution characteristics and the preset standard frequency distribution is calculated, and frequency components with a difference greater than a set threshold are marked as abnormal frequency components. Obtain a pre-defined library of characteristic frequencies of electromagnetic interference sources; The cosine similarity algorithm is used to obtain the matching degree between the abnormal frequency component and each interference frequency in the preset electromagnetic interference source feature frequency library. If the matching degree exceeds the preset threshold, the abnormal frequency component is determined to be a signal distortion frequency component caused by electromagnetic interference. The signal is filtered by a band-stop filter to remove the distorted frequency components. The filtered frequency domain signal is then subjected to an inverse Fourier transform to convert it back to a time domain signal.

[0011] Preferably, in the signal transmission module, the correction signal is marked with the marking content indicating high-quality transmission or anti-interference transmission, as follows: The amplitude and mean deviation of the corrected signal are statistically analyzed using a sliding window method to obtain the amplitude fluctuation, which reflects the signal stability. The power spectral density method is used to separate the power of the effective signal and the residual noise of the corrected signal to obtain the signal-to-noise ratio, which reflects the signal purity. Based on the preset thresholds for amplitude fluctuation and signal-to-noise ratio, corrected signals with amplitude fluctuation less than or equal to the preset threshold and signal-to-noise ratio greater than or equal to the preset threshold are marked as high-quality transmissions; otherwise, corrected signals are marked as anti-interference transmissions.

[0012] Preferably, in the signal transmission module, a preset transmission path set is obtained, and the preset transmission paths in the preset transmission path set are divided into high-quality transmission paths and anti-interference transmission paths, as follows; Get a set of preset transmission paths, and get the historical packet loss ratio and historical transmission delay for each preset transmission path in the set of preset transmission paths; A preset transmission path with a historical packet loss ratio less than or equal to a preset threshold and a historical transmission delay less than or equal to a preset threshold is designated as a high-quality transmission path. Use the preset transmission path other than the high-quality transmission path as the pre-selected transmission path; Obtain the historical average bit error rate and interference tolerance of the pre-selected transmission path; Pre-selected transmission paths with a historical average bit error rate less than or equal to a preset threshold and an interference tolerance strength greater than or equal to a preset threshold are used as anti-interference transmission paths.

[0013] An anti-interference transmission method for flue gas monitoring signals in high magnetic field areas of aluminum smelting includes the following steps: S1. In the high magnetic field zone of aluminum smelting, the raw signals of flue gas parameters are collected by sensors. S2. Perform low-pass filtering of the time-domain signal and band-pass filtering of the frequency-domain signal on the original flue gas parameter signal to obtain the preliminary filtered signal; S3. For the preliminary filtered signal, detect and correct the errors in the preliminary filtered signal, detect and remove the distortions in the preliminary filtered signal, and form a corrected signal. S4. Mark the correction signal as either high-quality transmission or anti-interference transmission; obtain a preset transmission path set, and divide the preset transmission paths in the preset transmission path set into high-quality transmission paths and anti-interference transmission paths; the correction signal marked as high-quality transmission is transmitted through the high-quality transmission path, and the correction signal marked as anti-interference transmission is transmitted through the anti-interference transmission path.

[0014] The anti-interference transmission system for monitoring flue gas in high magnetic field areas of aluminum smelting proposed in this invention has the following beneficial technical effects: 1. This application utilizes a combined time-domain low-pass filter and frequency-domain band-pass filter design in its signal filtering module, along with a dynamic parameter adjustment mechanism, to effectively filter out electromagnetic interference in the high magnetic field region of aluminum smelting. The low-pass filter specifically eliminates low-frequency interference caused by the power frequency magnetic field, while the band-pass filter removes high-frequency noise caused by inverter harmonics. Furthermore, the filter parameters are matched in real-time to the interference scenario using a smelting filter parameter library and a cosine similarity algorithm, enhancing adaptability to magnetic field fluctuations in the electrolytic cell and instantaneous interference from high-voltage electrical appliances. Simultaneously, the signal correction module corrects error data through trend analysis and CRC check, and combines spectral analysis and band-stop filtering to eliminate distortion components caused by electromagnetic interference, significantly improving the accuracy and integrity of the flue gas monitoring signal and mitigating the problem of noise, errors, and distortion in the original signal affecting monitoring accuracy.

[0015] 2. This application achieves anti-interference in signal transmission through a hierarchical labeling and path adaptation design of the signal transmission module. The corrected signal is labeled as either high-quality or anti-interference transmission type based on amplitude fluctuation and signal-to-noise ratio. Simultaneously, preset transmission paths are divided into corresponding types based on historical packet loss ratio, delay and bit error rate, and interference tolerance strength. This ensures that high-quality signals are transmitted through high-quality transmission paths, while susceptible signals are transmitted through anti-interference transmission paths. This on-demand matching transmission strategy not only guarantees stable signal transmission but also enhances the anti-interference capability of weak signals in high magnetic field environments, thereby improving the overall reliability of the transmission system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the anti-interference transmission system for monitoring flue gas in the high magnetic field zone of aluminum smelting according to the present invention. Figure 2 This is a flowchart of the anti-interference transmission method for flue gas monitoring signals in the high magnetic field zone of aluminum smelting according to the present invention. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] like Figure 1 The anti-interference transmission system for monitoring flue gas in the high magnetic field zone of aluminum smelting, as shown, includes: Signal acquisition module: In the high magnetic field area of ​​aluminum smelting, raw signals of flue gas parameters are acquired through sensors; The original signal contains noise caused by electromagnetic interference generated by the high magnetic field of the electrolytic cell and high-voltage electrical appliances such as rectifier transformers during the aluminum smelting process. The sensors used to collect raw signals of flue gas parameters include: a laser scattering sensor for collecting particulate matter concentration in flue gas, an electrochemical sensor for collecting harmful gas concentration in flue gas, and a thermocouple sensor for collecting flue gas temperature. Signal filtering module: performs low-pass filtering of the time domain signal and band-pass filtering of the frequency domain signal on the raw flue gas parameter signal to remove high-frequency noise and low-frequency interference in the signal and obtain a preliminary filtered signal; Signal correction module: For the initial filtered signal, detect and correct the errors in the initial filtered signal, detect and remove the distortions in the initial filtered signal, and form a corrected signal; Signal transmission module: Marks the correction signal, indicating whether it is high-quality transmission or anti-interference transmission; obtains a set of preset transmission paths, and divides the preset transmission paths in the set into high-quality transmission paths and anti-interference transmission paths; correction signals marked as high-quality transmission are transmitted through the high-quality transmission path, and correction signals marked as anti-interference transmission are transmitted through the anti-interference transmission path.

[0019] In an optional embodiment, the signal filtering module performs low-pass filtering in the time domain and band-pass filtering in the frequency domain on the original flue gas parameter signal to obtain a preliminary filtered signal, including the following steps: The time-domain components of the original flue gas parameter signal are extracted, and a low-pass filter is used to perform a low-pass filter operation to obtain the effective time-domain signal, filtering out the low-frequency interference caused by the power frequency magnetic field in the time-domain components; Fourier transform is applied to the original flue gas parameter signal to obtain the frequency domain components of the original flue gas parameter signal; A bandpass filter is used to perform a bandpass filtering operation to obtain the effective signal in the frequency domain; high-frequency noise caused by inverter harmonics is filtered out from the frequency domain components. The effective signal in the frequency domain is converted into a time domain signal form through inverse Fourier transform, and then combined with the effective signal in the time domain to form a preliminary filtered signal.

[0020] In an optional embodiment, the cutoff frequency parameter of the low-pass filter and the passband range parameter of the band-pass filter in the signal filtering module are generated in the following manner: Obtain the smelting filter parameter library, which includes the cutoff frequency parameters of low-pass filters and the passband range parameters of band-pass filters under multiple interference scenarios. Real-time interference features of the original flue gas parameter signals are extracted. The real-time interference features include the frequency peak value and amplitude variation period of the interference signal. The cosine similarity algorithm is used to obtain the similarity matching between the real-time interference features and multiple interference scenarios in the smelting filter parameter library. The interference scenario with the highest similarity is selected as the matching scenario. Extract the cutoff frequency parameters of the low-pass filter and the passband range parameters of the band-pass filter corresponding to the suitable scenario from the smelting filter parameter library, and use them as the cutoff frequency parameters of the low-pass filter and the passband range parameters of the band-pass filter.

[0021] Compared to fixed-parameter filtering, by dynamically adjusting the cutoff frequency parameter of the low-pass filter and the passband range parameter of the band-pass filter, the filtering technology can be deeply adapted to the time-varying interference scenarios in the high magnetic field region of aluminum smelting, thus alleviating the problem of poor adaptability of traditional filtering to magnetic field fluctuations in electrolytic cells and instantaneous interference from high-voltage electrical appliances.

[0022] In an optional embodiment, the signal correction module detects and corrects errors in the preliminary filtered signal by including the following steps: The data acquisition card extracts continuous data points of the preliminary filtered signal in the time series, and arranges them in the order of acquisition time to form a time-domain signal sequence. A trend analysis algorithm is used to generate a trend line for the time-domain signal sequence. Based on a preset deviation range, data points in the time-domain signal sequence that exceed the preset deviation range are identified as abnormal data points in the trend line of the time-domain signal sequence. The CRC check algorithm is used to perform data consistency verification on abnormal data points. Abnormal data points that fail the CRC check are regarded as error data points. The error data points are corrected by using linear interpolation to replace the original error data points.

[0023] In an optional embodiment, the signal correction module includes the following steps for detecting and correcting distortion in the initial filtered signal: The pre-filtered signal is subjected to spectrum analysis using a spectrum analyzer to obtain the frequency distribution characteristics of the signal. Frequency distribution characteristics include peak frequency and frequency band percentage; The difference between the frequency distribution characteristics and the preset standard frequency distribution is calculated, and frequency components with a difference greater than a set threshold are marked as abnormal frequency components. Obtain a pre-defined library of characteristic frequencies of electromagnetic interference sources; The cosine similarity algorithm is used to obtain the matching degree between the abnormal frequency component and each interference frequency in the preset electromagnetic interference source feature frequency library. If the matching degree exceeds the preset threshold, the abnormal frequency component is determined to be a signal distortion frequency component caused by electromagnetic interference. The signal is filtered by a band-stop filter to remove the distorted frequency components. The filtered frequency domain signal is then subjected to an inverse Fourier transform to convert it back to a time domain signal.

[0024] This application utilizes a combined time-domain low-pass filter and frequency-domain band-pass filter design in its signal filtering module, along with a dynamic parameter adjustment mechanism, to effectively filter out electromagnetic interference in the high magnetic field region of aluminum smelting. The low-pass filter specifically eliminates low-frequency interference caused by the power frequency magnetic field, while the band-pass filter removes high-frequency noise caused by inverter harmonics. Furthermore, the filter parameters are matched in real-time to interference scenarios using a smelting filter parameter library and a cosine similarity algorithm, enhancing adaptability to magnetic field fluctuations in the electrolytic cell and transient interference from high-voltage electrical appliances. Simultaneously, the signal correction module corrects error data through trend analysis and CRC checksum verification, and combines spectral analysis and band-stop filtering to eliminate distortion components caused by electromagnetic interference, significantly improving the accuracy and integrity of the flue gas monitoring signal and mitigating the impact of noise, errors, and distortion in the original signal on monitoring accuracy.

[0025] In an optional embodiment, the signal transmission module marks the correction signal with the marking content indicating high-quality transmission or interference-resistant transmission, as follows: The amplitude and mean deviation of the corrected signal are statistically analyzed using a sliding window method to obtain the amplitude fluctuation, which reflects the signal stability. The power spectral density method is used to separate the power of the effective signal and the residual noise of the corrected signal to obtain the signal-to-noise ratio, which reflects the signal purity. Based on the preset thresholds for amplitude fluctuation and signal-to-noise ratio, corrected signals with amplitude fluctuation less than or equal to the preset threshold and signal-to-noise ratio greater than or equal to the preset threshold are marked as high-quality transmissions; otherwise, corrected signals are marked as anti-interference transmissions.

[0026] In an optional embodiment, the preset threshold for amplitude fluctuation is 5%, and the preset threshold for signal-to-noise ratio is 30dB.

[0027] In an optional embodiment, the signal transmission module obtains a preset transmission path set and divides the preset transmission paths in the preset transmission path set into high-quality transmission paths and anti-interference transmission paths, as follows; Get a set of preset transmission paths, and get the historical packet loss ratio and historical transmission delay for each preset transmission path in the set of preset transmission paths; A preset transmission path with a historical packet loss ratio less than or equal to a preset threshold and a historical transmission delay less than or equal to a preset threshold is designated as a high-quality transmission path. Use the preset transmission path other than the high-quality transmission path as the pre-selected transmission path; Obtain the historical average bit error rate and interference tolerance of the pre-selected transmission path; Pre-selected transmission paths with a historical average bit error rate less than or equal to a preset threshold and an interference tolerance strength greater than or equal to a preset threshold are used as anti-interference transmission paths.

[0028] This application achieves anti-interference in signal transmission through a hierarchical labeling and path adaptation design of the signal transmission module. Corrected signals are labeled as high-quality or anti-interference transmission types based on amplitude fluctuation and signal-to-noise ratio. Simultaneously, preset transmission paths are divided into corresponding types based on historical packet loss ratio, delay and bit error rate, and interference tolerance strength. This ensures that high-quality signals are transmitted through high-quality transmission paths, while interference-prone signals are transmitted through anti-interference transmission paths. This on-demand matching transmission strategy not only guarantees the transmission of stable signals but also enhances the anti-interference capability of weak signals in high magnetic field environments, thereby improving the overall reliability of the transmission system.

[0029] like Figure 2 The method for preventing interference in the transmission of flue gas monitoring signals in the high magnetic field zone of aluminum smelting, as shown, includes the following steps: S1. In the high magnetic field zone of aluminum smelting, the raw signals of flue gas parameters are collected by sensors. S2. Perform low-pass filtering of the time-domain signal and band-pass filtering of the frequency-domain signal on the original flue gas parameter signal to obtain the preliminary filtered signal; S3. For the preliminary filtered signal, detect and correct the errors in the preliminary filtered signal, detect and remove the distortions in the preliminary filtered signal, and form a corrected signal. S4. Mark the correction signal as either high-quality transmission or anti-interference transmission; obtain a preset transmission path set, and divide the preset transmission paths in the preset transmission path set into high-quality transmission paths and anti-interference transmission paths; the correction signal marked as high-quality transmission is transmitted through the high-quality transmission path, and the correction signal marked as anti-interference transmission is transmitted through the anti-interference transmission path.

[0030] For clarification, "acquisition" in this application refers to obtaining the required content or data using existing technical means.

[0031] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0032] In the embodiments provided by this invention, it should be understood that the disclosed system or method can be implemented in other ways. For example, the embodiments of the invention described above are merely illustrative; for instance, the division of modules is only a logical functional division, and there may be other division methods in actual implementation.

[0033] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0034] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated module can be implemented in hardware or in the form of hardware plus software functional modules.

[0035] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the basic characteristics of the present invention.

[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting, characterized in that, include: Signal acquisition module: In the high magnetic field area of ​​aluminum smelting, raw signals of flue gas parameters are acquired through sensors; Signal filtering module: performs low-pass filtering of the time domain signal and band-pass filtering of the frequency domain signal on the raw flue gas parameter signal to obtain the preliminary filtered signal; Signal correction module: For the initial filtered signal, detect and correct the errors in the initial filtered signal, detect and remove the distortions in the initial filtered signal, and form a corrected signal; Signal transmission module: Marks the correction signal, indicating whether it is high-quality transmission or anti-interference transmission; obtains a set of preset transmission paths, and divides the preset transmission paths in the set into high-quality transmission paths and anti-interference transmission paths; correction signals marked as high-quality transmission are transmitted through the high-quality transmission path, and correction signals marked as anti-interference transmission are transmitted through the anti-interference transmission path. In the signal transmission module, the correction signal is marked with either high-quality transmission or anti-interference transmission, as follows: The amplitude and mean deviation of the corrected signal are statistically analyzed using a sliding window method to obtain the amplitude fluctuation, which reflects the signal stability. The power spectral density method is used to separate the power of the effective signal and the residual noise of the corrected signal to obtain the signal-to-noise ratio, which reflects the signal purity. Based on the preset thresholds for amplitude fluctuation and signal-to-noise ratio, corrected signals with amplitude fluctuation less than or equal to the preset threshold and signal-to-noise ratio greater than or equal to the preset threshold are marked as high-quality transmissions; otherwise, corrected signals are marked as anti-interference transmissions. In the signal transmission module, a preset transmission path set is obtained, and the preset transmission paths in the preset transmission path set are divided into high-quality transmission paths and anti-interference transmission paths, as follows; Get a set of preset transmission paths, and get the historical packet loss ratio and historical transmission delay for each preset transmission path in the set of preset transmission paths; A preset transmission path with a historical packet loss ratio less than or equal to a preset threshold and a historical transmission delay less than or equal to a preset threshold is designated as a high-quality transmission path. Use the preset transmission path other than the high-quality transmission path as the pre-selected transmission path; Obtain the historical average bit error rate and interference tolerance of the pre-selected transmission path; Pre-selected transmission paths with a historical average bit error rate less than or equal to a preset threshold and an interference tolerance strength greater than or equal to a preset threshold are used as anti-interference transmission paths.

2. The anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting according to claim 1, characterized in that, The signal filtering module performs low-pass filtering in the time domain and band-pass filtering in the frequency domain on the raw flue gas parameter signal to obtain a preliminary filtered signal, including the following steps: The time-domain components of the original flue gas parameter signal are extracted, and a low-pass filter is applied to obtain the effective time-domain signal. Fourier transform is applied to the original flue gas parameter signal to obtain the frequency domain components of the original flue gas parameter signal; By performing a bandpass filtering operation using a bandpass filter, the effective signal in the frequency domain is obtained; The effective signal in the frequency domain is converted into a time domain signal form through inverse Fourier transform, and then combined with the effective signal in the time domain to form a preliminary filtered signal.

3. The anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting according to claim 2, characterized in that, In the signal filtering module, the cutoff frequency parameter of the low-pass filter and the passband range parameter of the band-pass filter are generated in the following manner: Obtain the smelting filter parameter library, which includes the cutoff frequency parameters of low-pass filters and the passband range parameters of band-pass filters under multiple interference scenarios. Real-time interference features of the original flue gas parameter signals are extracted. The cosine similarity algorithm is used to obtain the similarity matching between the real-time interference features and multiple interference scenarios in the smelting filter parameter library. The interference scenario with the highest similarity is selected as the matching scenario. Extract the cutoff frequency parameters of the low-pass filter and the passband range parameters of the band-pass filter corresponding to the suitable scenario from the smelting filter parameter library, and use them as the cutoff frequency parameters of the low-pass filter and the passband range parameters of the band-pass filter.

4. The anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting according to claim 1, characterized in that, The signal correction module detects and corrects errors in the initial filtered signal, including the following steps: The data acquisition card extracts continuous data points of the preliminary filtered signal in the time series, and arranges them in the order of acquisition time to form a time-domain signal sequence. A trend analysis algorithm is used to generate a trend line for the time-domain signal sequence. Based on a preset deviation range, data points in the time-domain signal sequence that exceed the preset deviation range are identified as abnormal data points in the trend line of the time-domain signal sequence. The CRC check algorithm is used to perform data consistency verification on abnormal data points. Abnormal data points that fail the CRC check are regarded as error data points. The error data points are corrected by using linear interpolation to replace the original error data points.

5. The anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting according to claim 1 or 4, characterized in that, The signal correction module detects and corrects distortion in the initial filtered signal, including the following steps: The pre-filtered signal is subjected to spectrum analysis using a spectrum analyzer to obtain the frequency distribution characteristics of the signal. The difference between the frequency distribution characteristics and the preset standard frequency distribution is calculated, and frequency components with a difference greater than a set threshold are marked as abnormal frequency components. Obtain a pre-defined library of characteristic frequencies of electromagnetic interference sources; The cosine similarity algorithm is used to obtain the matching degree between the abnormal frequency component and each interference frequency in the preset electromagnetic interference source feature frequency library. If the matching degree exceeds the preset threshold, the abnormal frequency component is determined to be a signal distortion frequency component caused by electromagnetic interference. The signal is filtered by a band-stop filter to remove the distorted frequency components. The filtered frequency domain signal is then subjected to an inverse Fourier transform to convert it back to a time domain signal.

6. A method for anti-interference transmission of flue gas monitoring signals in high magnetic field areas of aluminum smelting, used in the anti-interference transmission system for flue gas monitoring signals in high magnetic field areas of aluminum smelting as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. In the high magnetic field zone of aluminum smelting, the raw signals of flue gas parameters are collected by sensors. S2. Perform low-pass filtering of the time-domain signal and band-pass filtering of the frequency-domain signal on the original flue gas parameter signal to obtain the preliminary filtered signal; S3. For the preliminary filtered signal, detect and correct the errors in the preliminary filtered signal, detect and remove the distortions in the preliminary filtered signal, and form a corrected signal. S4. Mark the correction signal as either high-quality transmission or anti-interference transmission; obtain a preset transmission path set, and divide the preset transmission paths in the preset transmission path set into high-quality transmission paths and anti-interference transmission paths; the correction signal marked as high-quality transmission is transmitted through the high-quality transmission path, and the correction signal marked as anti-interference transmission is transmitted through the anti-interference transmission path.

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