A monitoring system for preventing the wall of a mixing tank from being scratched

Abstract

The present invention provides a monitoring system for the anti-scratch wall of a stirring cylinder, which is arranged contactlessly outside the stirring cylinder and includes: a magnetic field generation module for generating a magnetic field; a magnetic field detection module for sensing the dynamic magnetic field generated when a stirring rod cuts the magnetic field and generating an analog electric signal; a signal acquisition and processing module for acquiring the analog electric signal, processing the analog electric signal, and generating a digital electric signal; and an operation detection module for obtaining the position of the stirring rod according to the digital electric signal to realize the detection of the anti-scratch wall of the stirring cylinder. Based on the magnetic induction method, the present invention does not require any modification to the existing stirring cylinder, does not destroy the structure, and does not affect the on-site process, thereby realizing non-contact online detection of the stirring rod position.

Description

Technical Field

[0001] The invention relates to the technical field of equipment detection, and in particular to a monitoring system for anti-scratch walls of a mixing tank. Background Art

[0002] After long-term operation, the stirring rod of the slurry mixing tank is at risk of scratching the tank wall due to mechanical aging. The metal debris produced by scratching the tank wall will contaminate the entire tank slurry and cause damage to the mixing tank, resulting in economic losses and affecting production efficiency. Therefore, it is necessary to perform online detection of the position of the stirring rod, and issue a prompt or alarm when the stirring rod reaches a dangerous distance, so as to help the staff take preventive measures.

[0003] In the existing technology, the production is generally stopped for maintenance, which has low production efficiency. This method cannot be detected online and has production risks. There is a proposal to embed a sensor unit in the stirring rod and add a corresponding detection device outside the stirring barrel for detection, but this will destroy the stirring rod structure, increase the process, and the embedded sensor unit will have the risk of contaminating the slurry.

[0004] Therefore, how to detect the anti-scratch wall of the mixing tank without affecting the production process and destroying the structure of the mixing system is an urgent problem to be solved. Summary of the invention

[0005] The present invention provides a monitoring system for an anti-scratch wall of a mixing cylinder, which is used to solve the problem in the prior art that it is difficult to detect the anti-scratch wall of a mixing cylinder without affecting the production process and destroying the structure of the mixing system.

[0006] In a first aspect, the present invention provides a monitoring system for an anti-scratch wall of a mixing tank, characterized in that the system is arranged contactlessly outside the mixing tank, and comprises: a magnetic field generating module, a magnetic field detecting module, a signal collecting and processing module, and an operation detecting module;

[0007] The magnetic field generating module is used to generate a magnetic field; wherein the magnetic field penetrates the stirring cylinder and acts on the stirring rod of the stirring cylinder;

[0008] The magnetic field detection module is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field and generate an analog electrical signal;

[0009] The signal acquisition and processing module is used to acquire the analog electrical signal, process the analog electrical signal, and generate a digital electrical signal;

[0010] The operation detection module is used to obtain the position of the stirring rod according to the digital electrical signal to realize the detection of the anti-scratch wall of the stirring cylinder.

[0011] According to the monitoring system provided by the present invention, the magnetic field generating module and the magnetic field detecting module are located on the same side of the stirring cylinder; the magnetic field generating module includes a permanent magnet, and the magnetic field detecting module includes two induction coils; the two induction coils are coaxially arranged at both ends of the permanent magnet, and the axis is perpendicular to the cylinder surface of the stirring cylinder; wherein the induction coil farther away from the stirring cylinder is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field, and generates a first electromotive force signal; the induction coil closer to the stirring cylinder is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field, and generates a second electromotive force signal.

[0012] According to the monitoring system provided by the present invention, the signal acquisition and processing module is used to perform differential amplification processing on the first electromotive force signal and the second electromotive force signal, and generate a digital electrical signal.

[0013] According to the monitoring system provided by the present invention, the signal acquisition and processing module includes a differential amplification module, a filtering module and an analog-to-digital conversion module; the differential amplification module is used to perform differential amplification processing on the first electromotive force signal and the second electromotive force signal; the filtering module is used to filter the differential amplified signal after the differential amplification processing; the analog-to-digital conversion module is used to perform analog-to-digital conversion on the filtered differential amplified signal to generate a digital electrical signal.

[0014] According to the monitoring system provided by the present invention, the operation detection module is further used to generate an alarm signal when it is determined that the position of the stirring rod is within a preset range.

[0015] According to the monitoring system provided by the present invention, the operation detection module obtains the stirring rod position according to the digital electrical signal to realize the detection of the anti-scratch wall of the stirring cylinder, including: performing Fourier transform on the digital electrical signal to obtain the corresponding signal characteristic value;

[0016] According to the type of the stirring cylinder and the stirring rod rotation speed, calling the corresponding stirring rod position prediction model from a pre-built database; the database includes stirring rod position prediction models for different types of stirring cylinders and stirring rod rotation speeds;

[0017] The signal characteristic value is input into the stirring rod position prediction model to obtain the corresponding stirring rod position.

[0018] According to the monitoring system provided by the present invention, the digital electrical signal is subjected to Fourier transform to obtain the corresponding signal characteristic value, including: performing Fourier transform on the digital electrical signal to obtain a spectrum diagram of the digital electrical signal; analyzing the energy proportion occupied by different frequency components through the spectrum diagram; calculating the spectrum energy within a preset frequency range, and using the spectrum energy as the signal characteristic value.

[0019] The monitoring system provided according to the present invention includes: the stirring rod position is the distance between the stirring rod and the cylinder wall.

[0020] According to the monitoring system provided by the present invention, the operation detection module is a mobile terminal.

[0021] The monitoring system for the anti-scratching wall of the stirring cylinder provided by the present invention is based on the magnetic induction method, does not require any modification to the existing stirring cylinder, does not damage the structure, and will not affect the on-site process, thereby realizing non-contact online detection of the stirring rod position.

[0022] The monitoring system for anti-scratching walls of a stirring cylinder provided by the present invention uses spectrum energy within a specific frequency range as the signal characteristic value of a stirring rod, has a wider range of application scenarios, and is suitable for stirring cylinders with any number of stirring rods, any structure, and any rotation speed.

[0023] In the monitoring system for the anti-scratch wall of the mixing cylinder provided by the present invention, two induction coils are arranged in the magnetic field detection module to collect differential signals, which can effectively reduce noise interference and improve the signal-to-noise ratio of the signal to obtain more accurate detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be introduced one by one below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of a monitoring system for anti-scratching walls of a mixing tank provided by the present invention;

[0026] Figure 2 It is a schematic diagram of the principle of position detection using electromagnetic induction provided by the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that in the description of the embodiments of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method, article or device including the elements. The orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0029] Based on user needs (non-destructive) and on-site operating condition analysis (frequent moving and spray cleaning of the tank), the monitoring system provided by the present invention can be arranged outside the mixing tank (mixing system), there is no physical contact, and the water film attached to the slurry and the tank surface has no effect on the detection results.

[0030] Figure 1 Schematic diagram of the structure of the monitoring system for the anti-scratching wall of the mixing tank provided by the present invention, such as Figure 1 As shown, the system includes: a magnetic field generating module 110, a magnetic field detecting module 120, a signal collecting and processing module 130 and an operation detecting module 140;

[0031] The magnetic field generating module 110 is used to generate a magnetic field; wherein the magnetic field penetrates the stirring tank and acts on the stirring rod of the stirring tank.

[0032] The function of the magnetic field generation module is to generate a stable magnetic field, which can be achieved by electromagnets or permanent magnets. Electromagnets can control the magnetic field strength by adjusting the current, while permanent magnets provide a constant magnetic field. The magnetic field generation module is usually arranged outside the mixing tank to ensure that the magnetic field can penetrate the wall of the mixing tank and interact with the stirring rod inside.

[0033] The magnetic field detection module 120 is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field and generate an analog electrical signal.

[0034] The stirring rod cuts the magnetic flux lines and generates eddy currents inside it, which then generate a dynamic magnetic field. The magnetic field detection module can use a Hall effect sensor or a magnetic induction coil. These sensors can capture the changes in the dynamic magnetic field and convert them into voltage or current fluctuations. The magnetic field detection module is also arranged outside the stirring tank, opposite to or adjacent to the magnetic field generation module.

[0035] The signal acquisition and processing module 130 is used to acquire the analog electrical signal, process the analog electrical signal, and generate a digital electrical signal.

[0036] The function of the signal acquisition and processing module is to collect the analog electrical signal from the magnetic field detection module, amplify it, filter it, and then convert the analog signal into a digital signal. The present invention can use an analog-to-digital converter (ADC) to complete the conversion of analog signals to digital signals. At the same time, the present invention can also process the analog electrical signal through a signal processing circuit such as an amplifier and a filter to ensure the quality of the signal.

[0037] The operation detection module 140 is used to obtain the position of the stirring rod according to the digital electrical signal to realize the detection of the anti-scratch wall of the stirring cylinder.

[0038] The operation detection module may be a microprocessor or a computer control system, which executes a predetermined algorithm to analyze the digital electrical signal and determine the position of the stirring rod. For example, the operation detection module is a mobile terminal.

[0039] The monitoring system for the anti-scratching wall of the stirring cylinder provided by the present invention is based on the magnetic induction method, does not require any modification to the existing stirring cylinder, does not damage the structure, and will not affect the on-site process, thereby realizing non-contact online detection of the stirring rod position.

[0040] Based on the contents of the above embodiments, as an optional embodiment, the monitoring system provided by the present invention, the magnetic field generating module and the magnetic field detecting module are located on the same side of the stirring cylinder; the magnetic field generating module includes a permanent magnet, and the magnetic field detecting module includes two induction coils; the two induction coils are coaxially arranged at both ends of the permanent magnet, and the axis is perpendicular to the cylinder surface of the stirring cylinder; wherein, the induction coil farther away from the stirring cylinder is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field, and generates a first electromotive force signal; the induction coil closer to the stirring cylinder is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field, and generates a second electromotive force signal.

[0041] Specifically, Figure 2 Schematic diagram of the principle of position detection using electromagnetic induction provided by the present invention, such as Figure 2As shown, two induction coils (which can be cylinders) are coaxially arranged at both ends of a permanent magnet (which can be a cylinder), and the axis is perpendicular to the surface of the tank. The magnetic field generated by the permanent magnet (blue arrow curve) can directly penetrate the tank and the slurry. When the stirring rod is stirred, the rod cuts the magnetic flux lines and generates eddy currents (red dotted lines) inside it, which then generate a dynamic magnetic field (red arrow curve). Dynamic magnetic field B e Induction electromotive force is generated inside the two induction coils. Specifically, the induction coil far from the mixing cylinder generates a first electromotive force signal V 1 , the induction coil closer to the mixing tank generates a second electromotive force signal V 2 .

[0042]

[0043] φ ei is the magnetic flux generated by the dynamic magnetic field at the induction coil, and N is the number of turns of the coil.

[0044] Due to the characteristic of the exponential decay of the magnetic field with distance, the induced electromotive force (i.e., the first electromotive force signal) of the induction coil farther from the stirring cylinder is smaller, and the induced electromotive force (i.e., the second electromotive force signal) of the induction coil closer to the stirring cylinder is larger, and the influence of environmental noise on the two induction coils can be considered to be the same. Therefore, the present invention can eliminate the interference of environmental noise by differentially measuring the electromotive force values ​​of the two induction coils, and realize the detection of the stirring rod position.

[0045] Optionally, the signal acquisition and processing module is used to perform differential amplification processing on the first electromotive force signal and the second electromotive force signal, and generate a digital electrical signal.

[0046] Optionally, the signal acquisition and processing module includes a differential amplification module, a filtering module and an analog-to-digital conversion module. The specific functions and implementation methods of each submodule are described in detail below.

[0047] The differential amplifier module is used to perform differential amplification processing on the first electromotive force signal (remote coil signal) and the second electromotive force signal (near coil signal); the differential amplifier is used to amplify the difference between the two signals, thereby improving the signal-to-noise ratio of the signal. The differential amplifier can effectively suppress common-mode noise and enhance useful signals.

[0048] The filtering module is used to filter the differentially amplified signal to remove unnecessary noise and interference. The present invention can use an analog filter, such as a low-pass filter, a band-pass filter or a high-pass filter, and select a suitable filter according to the frequency characteristics of the signal and the type of noise. The filter selectively attenuates or amplifies the frequency response of the signal, thereby retaining the signal within the useful frequency range and weakening or removing the noise component.

[0049] The analog-to-digital conversion module is used to convert the filtered analog signal (differential amplified signal) into a digital signal. An analog-to-digital converter (ADC) is used to convert the analog signal into a digital signal. Appropriate sampling rate and quantization bits are selected to ensure that the converted signal can accurately reflect the information of the original signal.

[0050] Through the above embodiments, the signal acquisition and processing module in the present invention can effectively extract useful signals from the outputs of the two induction coils, convert them into digital form, and provide an accurate data basis for the operation detection module. This processing method not only improves the reliability of the signal, but also provides a solid foundation for subsequent intelligent analysis.

[0051] As an alternative embodiment, for the monitoring system provided by the present invention, the operation detection module is further configured to generate an alarm signal when it is determined that the position of the stirring rod is within a preset interval.

[0052] The present invention can set a preset interval. When the position of the stirring rod falls within this interval, the system believes that the stirring rod is close to the cylinder wall and there is a risk of scratching. Once it is determined that the position of the stirring rod is within the preset interval, an alarm signal is immediately generated, and the operator is notified or corresponding protection measures are automatically activated.

[0053] Assume that the standard distance between the stirring rod and the inner wall of the cylinder is D, and the actual distance is x. The closest distance to the cylinder wall during stirring is d1, and the farthest distance is d2 (d1 < D < d2). Then:

[0054] Safe interval: d1 < D < d2.

[0055] Warning interval: x > d2 or x < d1.

[0056] When it is detected that the position x of the stirring rod satisfies x > d2 or x < d1, the system generates an alarm signal.

[0057] Through the above settings, the operation detection module in the present invention can effectively monitor the position of the stirring rod and generate an alarm signal when necessary, thereby helping the staff to take timely measures to prevent the stirring rod from scratching the cylinder wall, protecting the equipment and ensuring the smooth progress of production.

[0058] Based on the content of the above embodiments, as an alternative embodiment, for the monitoring system provided by the present invention, the operation detection module obtains the position of the stirring rod according to the digital electrical signal to implement the detection of anti-scratching of the stirring cylinder, including:

[0059] (1) Perform a Fourier transform on the digital electrical signal to obtain the corresponding signal characteristic values.

[0060] The Fast Fourier Transform (FFT) algorithm is used to convert the digital electrical signal in the time domain into a spectrum in the frequency domain.

[0061] The characteristic values ​​of the signal are extracted from the spectrum, and these characteristic values ​​usually include the main frequency, secondary frequency, phase information, etc. of the spectrum. In the present invention, the focus is on the spectrum energy within a specific frequency range.

[0062] (2) According to the type of the mixing cylinder and the rotation speed of the stirring rod, the corresponding stirring rod position prediction model is called from the pre-built database.

[0063] During the system development phase, data on the relationship between signal characteristic values ​​and stirring rod positions under different stirring cylinder types and stirring rod speeds are collected through experiments or simulations. These data are used to train the stirring rod position prediction model.

[0064] A machine learning method (such as linear regression, support vector machine, neural network, etc.) is used to train a stir bar position prediction model. Each model corresponds to a specific stirring cylinder type and a stirring rod speed combination. The prediction model in the present invention can also be a signal characteristic value-stirring rod position function, and the function can be obtained by fitting multiple sets of signal characteristic values ​​and stirring rod position data collected in advance.

[0065] The trained models are stored in a database and each model is assigned a unique identifier to facilitate calling according to the mixing cylinder type and stirring rod speed.

[0066] Assume that you have the following models in your database:

[0067] Model A: For mixing tank type 1, stirring rod speed 100RPM.

[0068] Model B: For mixing tank type 1, stirring rod speed 150RPM.

[0069] Model C: For mixing tank type 2, stirring rod speed 100RPM.

[0070] When the system recognizes that the type of mixing cylinder currently in use is 1 and the stirring rod speed is 100RPM, model A is called from the database.

[0071] It should be noted that as the equipment ages or process conditions change, the accuracy of the model may decrease, so the model needs to be retrained and updated regularly.

[0072] (3) The signal characteristic value is input into the stirring rod position prediction model to obtain the corresponding stirring rod position.

[0073] The signal feature value extracted from the Fourier transform is used as an input variable, and the feature value is input into the corresponding stirring rod position prediction model, and the model outputs a predicted stirring rod position.

[0074] The monitoring system provided by the present invention can effectively predict the position of the stirring rod in real time according to the stirring rod rotation speed and the stirring cylinder type by using a pre-trained model, and take timely measures to avoid the occurrence of wall scraping accidents.

[0075] As an optional embodiment, the monitoring system provided by the present invention performs Fourier transform on the digital electrical signal to obtain the corresponding signal characteristic value, including:

[0076] (1) Performing Fourier transform on the digital electrical signal to obtain a frequency spectrum of the digital electrical signal.

[0077] (2) The energy distribution of the signal is analyzed by the spectrum obtained through Fourier transform, that is, the energy ratio of different frequency components.

[0078] (3) Calculating spectrum energy within a relevant frequency range based on the spectrum of the digital electrical signal, and using the spectrum energy as the signal characteristic value.

[0079] The relevant frequency range may be an artificially preset frequency range that can better characterize the signal characteristics, and may be determined through multiple experiments.

[0080] The spectrum energy can be obtained by integrating or summing the energy at each point in the frequency range.

[0081] The present invention can effectively extract signal characteristic values ​​from digital electrical signals and use them for further position calculation, thereby realizing effective detection of the anti-scratch wall of the mixing cylinder.

[0082] The method for constructing the stirring rod position prediction model is briefly described below.

[0083] Building a stirring rod position prediction model is one of the key steps to realize the anti-scratch wall detection system of the mixing cylinder. This process requires obtaining the signal characteristic values ​​of the stirring rod at different positions through experiments or simulations, and establishing a mapping relationship between the two based on this. The following is the specific construction method:

[0084] (1) Experimental preparation

[0085] Experimental platform: Build an experimental platform, including a stirring tank, a stirring rod, a magnetic field generation module (permanent magnet), a magnetic field detection module (two induction coils), a signal acquisition and processing module, etc.

[0086] Position Control: Ensures that the position of the stir bar can be precisely controlled and maintained during the experiment.

[0087] (2) Data Collection

[0088] Position setting: Set a series of different positions of the stirring rod, which should cover all possible working areas of the stirring rod in the mixing tank.

[0089] Signal recording: At each set position, record the first electromotive force signal and the second electromotive force signal generated when the stirring rod cuts the magnetic field. Make sure to record a long enough period of time to obtain a complete signal cycle.

[0090] (3) Signal processing

[0091] Perform Fourier transform on the collected analog signal to convert the time domain signal into a frequency domain signal. Extract characteristic values ​​from the Fourier transformed signal, such as main frequency, secondary frequency, phase difference, spectrum energy, etc. These characteristic values ​​reflect the motion state of the stirring rod in the magnetic field.

[0092] The calculation method of the spectrum energy may refer to the above embodiment, which will not be described in detail here.

[0093] (4) Data collation

[0094] Data pairing: Pair the signal feature value corresponding to each position with that position to form a data set.

[0095] Data cleaning: Remove outliers and noise to ensure data accuracy and consistency.

[0096] (5) Model construction

[0097] The present invention can select a regression model, a neural network or other machine learning model to establish a mapping relationship between the signal characteristic value and the stirring rod position; use the sorted data set to train the selected model, and optimize the model parameters through repeated iterations until the model can accurately predict the position of the stirring rod.

[0098] The present invention can also construct a signal characteristic value-stirring rod position function for the signal characteristic value corresponding to each position as a stirring rod position prediction model.

[0099] The present invention can construct a signal characteristic value-stirring rod position function suitable for different stirring cylinder types and stirring rod rotation speeds, thereby realizing effective detection of the anti-scratch wall of the stirring cylinder.

[0100] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0101] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A monitoring system for anti-scratch wall of a mixing tank, characterized in that: The system is arranged contactlessly outside the mixing tank, and includes: a magnetic field generation module, a magnetic field detection module, a signal acquisition and processing module, and an operation and detection module; The magnetic field generating module is used to generate a magnetic field; wherein the magnetic field penetrates the stirring cylinder and acts on the stirring rod of the stirring cylinder; The magnetic field detection module is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field and generate an analog electrical signal; The magnetic field generating module and the magnetic field detecting module are located on the same side of the mixing tank; The magnetic field generating module includes a permanent magnet, and the magnetic field detecting module includes two induction coils; the two induction coils are coaxially arranged at two ends of the permanent magnet, and the axes are perpendicular to the surface of the mixing tank; Among them, the induction coil farther from the stirring cylinder is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field, and generate a first electromotive force signal; the induction coil closer to the stirring cylinder is used to sense the dynamic magnetic field generated when the stirring rod cuts the magnetic field, and generate a second electromotive force signal; The signal acquisition and processing module is used to acquire the analog electrical signal, process the analog electrical signal, and generate a digital electrical signal; wherein the processing of the analog electrical signal includes: differentially amplifying the first electromotive force signal and the second electromotive force signal; The operation detection module is used to obtain the position of the stirring rod according to the digital electrical signal to realize the detection of the anti-scratch wall of the stirring cylinder; specifically includes: Performing Fourier transform on the digital electrical signal to obtain corresponding signal characteristic values; According to the type of the stirring cylinder and the stirring rod rotation speed, calling the corresponding stirring rod position prediction model from a pre-built database; the database includes stirring rod position prediction models for different types of stirring cylinders and stirring rod rotation speeds; Inputting the signal characteristic value into the stirring rod position prediction model to obtain the corresponding stirring rod position; Performing Fourier transform on the digital electrical signal to obtain corresponding signal characteristic values; specifically including: Performing Fourier transform on the digital electrical signal to obtain a frequency spectrum of the digital electrical signal; Analyze the energy proportions of different frequency components based on the spectrum diagram; The spectrum energy within a preset frequency range is calculated, and the spectrum energy is used as the signal characteristic value.

2. The monitoring system according to claim 1, characterized in that: The signal acquisition and processing module includes a differential amplification module, a filtering module and an analog-to-digital conversion module; The differential amplification module is used to perform differential amplification processing on the first electromotive force signal and the second electromotive force signal; The filtering module is used to filter the differential amplified signal after the differential amplification process; The analog-to-digital conversion module is used to perform analog-to-digital conversion on the filtered differential amplified signal to generate a digital electrical signal.

3. The monitoring system according to claim 1, characterized in that: The operation detection module is also used to generate an alarm signal when it is determined that the stirring rod position is within a preset range.

4. The monitoring system according to claim 1, characterized in that: include: The stirring rod position is the distance between the stirring rod and the cylinder wall.

5. The monitoring system according to claim 1, characterized in that: The operation detection module is a mobile terminal.

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