Method and system for screw feeding and pipe protection of a screw ship unloader

Abstract

The application provides a spiral feeding and pipeline protection method and system of a spiral ship unloader, the method comprising: collecting motor speed, current and torque data and generating an experience data set during normal operation of the spiral conveyor; performing data cleaning on abnormal values in the experience data set; establishing experience function models of motor current and torque based on the cleaned experience data set; collecting motor speed, current and torque data in real time and performing data cleaning; comparing the cleaned real-time speed, current and torque data with the experience function models to determine the operation of the spiral conveyor, and stopping and alarming if the spiral conveyor is abnormally operated. The application establishes experience function models of speed and motor current and torque, determines the operation of the spiral conveyor through comprehensive data of motor speed, current and torque, avoids determination errors caused by using single type data, and improves the accuracy of early warning.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of spiral ship unloader fault monitoring, and particularly relates to a spiral feeding and pipeline protection method and system for a spiral ship unloader. BACKGROUND

[0002] The spiral ship unloader adopts Archimedes axial constant-diameter spiral conveying pipes to transport bulk cargo, and its main mechanisms are vertical spiral conveyors and horizontal spiral conveyors. When the internal structure of the spiral conveyor is abnormal or metal foreign matter is stuck during feeding, improper detection and protection measures can cause fatal damage to the spiral conveyor.

[0003] Currently, the industry mainly relies on a number of temperature sensors to detect temperature abnormalities or detect whether the driving main motor current is abnormal to protect. For example, the invention patent with the publication number CN112098837A discloses a shaftless spiral conveyor fault alarm method and device, which compares the real-time current value of the driving motor with a specific current value range to determine whether the working state of the shaftless spiral conveyor is abnormal. If it is abnormal, an alarm prompt is issued. However, the above protection method has the following disadvantages: (1) a large number of temperature sensors need to be installed, and although the horizontal spiral pipeline can be installed with temperature sensors, it is difficult to install and maintain the vertical spiral pipeline; (2) only relying on current abnormality detection has a high error rate and is unstable.

[0004] Therefore, there is a need for a spiral feeding and pipeline protection method for a spiral ship unloader that is easy to maintain and has good stability. SUMMARY

[0005] Therefore, the application provides a spiral feeding and pipeline protection method and system for a spiral ship unloader to solve the problem of high error rate in abnormal monitoring of the existing spiral ship unloader.

[0006] In a first aspect, the application discloses a spiral feeding and pipeline protection method for a spiral ship unloader, which comprises:

[0007] During normal operation of the spiral conveyor, motor speed, current and torque data are collected and an experience data set is generated;

[0008] The abnormal values in the experience data set are cleaned up;

[0009] Based on the cleaned experience data set, experience function models of motor current and torque are established respectively;

[0010] Real-time motor speed, current and torque data are collected and cleaned up;

[0011] The cleaned real-time speed, current and torque data are compared with the experience function models to determine the operation of the spiral conveyor, and if the spiral conveyor operates abnormally, the machine is stopped and an alarm is issued.

[0012] On the basis of the above technical solutions, preferably, the spiral conveyor during normal operation, the motor speed, current and torque data and generate experience data set specifically includes:

[0013] Through the PLC control system and the spiral unloading machine of each drive motor frequency converter fieldbus communication, each motor current transmitter data access PLC control system analog input module;

[0014] Spiral conveyor normal taking material, according to the coal quality varieties, through the PLC control system respectively record in the set motor speed under the taking head drive motor, vertical spiral drive motor and horizontal spiral drive motor current curve and torque curve;

[0015] According to the current curve and torque curve respectively get spiral conveyor normal operation, set motor speed under the different coal quality taking material taking head drive motor, vertical spiral drive motor and horizontal spiral drive motor current database, torque database, to establish the corresponding experience data set.

[0016] On the basis of the above technical solutions, preferably, the experience function model of motor current and torque based on the experience data set after cleaning specifically includes:

[0017] The experience function model of current I x Is: I x ∈F(x)={K a *X1|X1∈U1}

[0018] The experience function model of torque T y Is: T y ∈F(y)={K b *X2|X2∈U2}

[0019] Wherein, K a , K b Respectively represent the experience of taking different coal quality, current, torque proportionality coefficient, X1 is the motor current experience data set U1 in any one element, X2 is the motor torque experience data set U2 in any one element.

[0020] On the basis of the above technical solutions, preferably, the real-time acquisition of motor speed, current and torque data and data cleaning specifically includes:

[0021] According to the current experience data set to draw current box plot, get the upper edge and lower edge of current box plot, the current data points higher than the upper edge, or lower than the lower edge of the data points are eliminated;

[0022] According to the torque empirical data set, a torque box plot is drawn, the upper edge and the lower edge of the torque box plot are obtained, and the data points higher than the upper edge or lower than the lower edge in the real-time collected torque data are removed.

[0023] On the basis of the above technical scheme, preferably, the comparison of the cleaned real-time speed, current and torque data with the empirical function model to determine the running condition of the screw conveyor, and if the screw conveyor runs abnormally, stopping and alarming specifically include:

[0024] The set motor speed value of the screw conveyor is obtained, and whether the real-time collected motor speed is consistent with the set motor speed value is judged, if not, it is determined that the screw conveyor runs abnormally, and stopping and alarming;

[0025] If the real-time collected speed is consistent with the set speed value, it is judged whether the cleaned real-time current data conforms to the empirical function model of the current, and whether the cleaned real-time torque data conforms to the empirical function model of the torque, if the sum of the deviations of the cleaned real-time current data and the cleaned real-time torque data from the corresponding empirical function model is greater than a preset threshold, it is determined that the screw conveyor runs abnormally, and stopping and alarming.

[0026] On the basis of the above technical scheme, preferably, if the sum of the deviations of the cleaned real-time current data and the cleaned real-time torque data from the corresponding empirical function model is greater than a preset threshold, it is determined that the screw conveyor runs abnormally, and stopping and alarming specifically include:

[0027] The deviation of the current is defined as K1:

[0028] The deviation of the torque is defined as K2:

[0029] Wherein, i x is the real-time collection value of the motor current after cleaning at a fixed feeding speed, t y is the real-time collection value of the motor torque after cleaning at a fixed feeding speed, is the average value of the motor empirical function model F(x); is the average value of the motor torque empirical function model F(y);

[0030] The sum of the deviations of the cleaned real-time current data and the cleaned real-time torque data from the corresponding empirical function model is K:

[0031]

[0032] If the relationship K≥K n is always established within a continuous period of time, it is determined that the screw feeding and the pipeline run abnormally, otherwise, it is normal, wherein K nTo fix the experience value.

[0033] On the basis of the above technical solutions, preferably, the method further comprises:

[0034] The PLC control system bus current value I1 and the analog current value I2 accessed by the motor current transmitter are collected at fixed intervals, if |I1-I2|<N, it is determined that the current data is stable, N is a preset current threshold, if |I1-I2|≥N occurs multiple times, it is unstable, an alarm is issued, and the motor speed, current and torque data collected under instability are discarded.

[0035] In the second aspect of the application, a spiral feeding and pipeline protection system of a spiral ship unloader is disclosed, the system comprises:

[0036] The PLC control system: in field bus communication with the frequency converter of each driving motor of the spiral ship unloader, and the motor current transmitter data is accessed to the analog input module of the PLC control system, for collecting motor speed, current and torque data and generating an experience data set during normal operation of the spiral conveyor; real-time collection of motor speed, current and torque data;

[0037] The data processing module: for data cleaning of the abnormal values in the experience data set or the real-time collected motor speed, current and torque data, and for establishing an experience function model of the motor current and torque based on the cleaned experience data set;

[0038] The abnormality judgment module: for comparing the real-time speed, current and torque data after data cleaning with the experience function model, determining the operation condition of the spiral conveyor, and stopping and alarming if the spiral conveyor is abnormally operated.

[0039] The present application has the following beneficial effects compared with the prior art:

[0040] 1) The present application collects a large amount of motor speed, current and torque data and performs data cleaning, establishes an experience function model of the speed and motor current and torque, determines the operation condition of the spiral conveyor through the comprehensive data of the motor speed, current and torque, avoids the determination error caused by using only a single type of data, and improves the accuracy of the early warning; the present application fully utilizes the existing configuration to collect relevant real-time operation data, has a simple structure, and through appropriate data processing, the protection accuracy and stability of the spiral conveyor are greatly improved, and the maintenance during the later operation period is simple;

[0041] 2) The application establishes an experience function model based on mass normal operation data, defines deviation based on the ratio of collected data and the mean value of the experience function model, and judges whether it is abnormal by comparing the sum of the deviation of the cleaned real-time current data and the cleaned real-time torque data and the corresponding experience function model with a preset threshold, which can fully utilize the advantages of big data, improve the accuracy of abnormal judgment, and reduce misjudgment;

[0042] 3) The application collects PLC control system bus current value and motor current transmitter connected analog current value at fixed time intervals, and verifies stability through double current data collection, thereby improving system stability and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0044] Figure 1 It is a structural schematic diagram of the screw ship unloader;

[0045] Figure 2 It is a structural schematic diagram of the horizontal screw conveyor of the screw ship unloader;

[0046] Figure 3 It is a flow chart of the spiral feeding and pipeline protection method of the screw ship unloader of the present application;

[0047] Figure 4 It is a schematic diagram of the connection relationship between the PLC control system and each motor;

[0048] Figure 5 It is a part of the current curve of each drive motor when the feeding speed is fixed at speed V1 when taking a certain coal quality;

[0049] Figure 6 It is a part of the current curve of each drive motor when the feeding speed is fixed at speed V2 when taking the same coal quality. Figure 5 DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. ​

[0051] Figure 1 This is a schematic diagram of a screw unloader, whose main components are a vertical screw conveyor and a horizontal screw conveyor. Figure 2 This is a schematic diagram of the horizontal screw conveyor structure of a screw unloader. Figure 2 As can be seen from the structure, when abnormalities such as metal foreign objects getting stuck occur during the feeding process, the screw conveyor on the screw unloader is easily damaged. Therefore, it is necessary to monitor the operating status of the screw unloader in real time to ensure normal feeding and avoid pipeline damage.

[0052] Please see Figure 1 This invention proposes a method for screw feeding and pipeline protection of a screw unloader, the method comprising:

[0053] S1. During normal operation of the screw conveyor, collect motor speed, current and torque data and generate an experience dataset.

[0054] This invention uses a PLC control system for data acquisition. For example... Figure 2 As shown, the PLC control system communicates with the frequency converters of each drive motor of the screw unloader via fieldbus, and the data from the motor current transmitters is input to the analog input module of the PLC control system. The PLC control system of this invention includes a frequency converter configuration communication module, and the CPU module in the PLC control system supports the fieldbus protocol of this frequency converter communication module, thereby enabling data communication.

[0055] During the initial commissioning phase, when the screw conveyor is normally picking up material, the current and torque curves of the head drive motor, vertical screw drive motor, and horizontal screw drive motor are recorded by the PLC control system at a set motor speed, depending on the type of coal being picked up. Based on the current and torque curves, current and torque databases for the head drive motor, vertical screw drive motor, and horizontal screw drive motor are established for different coal types at a set motor speed during normal operation of the screw conveyor, resulting in corresponding empirical datasets.

[0056] Figure 5 The figure shows partial current curves of the drive motors of each component when taking a certain type of coal at a fixed speed of V1 (i.e., the speed of each component motor is constant). Series 1: Current of the drive motor of the taking head; Series 2: Current of the drive motor of the vertical screw; Series 3: Current of the drive motor of the horizontal screw.

[0057] Figure 6 The image shows the selection. Figure 5 For the same coal quality, when the material handling speed is fixed at speed V2 (i.e., the speed of each component motor is constant), the partial current curves of the drive motors of each component are shown. Among them, Series 1: current of the material handling head drive motor; Series 2: current of the vertical screw drive motor; Series 3: current of the horizontal screw drive motor.

[0058] From the above curve, in the normal operation process, when the taking speed is constant, the current and torque of each drive motor will be in a fixed data set, and there will be no large deviation, and the trend of the above curve is consistent under different coal quality. Therefore, the present application generates corresponding experience data set based on current curve and torque curve for abnormality determination.

[0059] S2, data cleaning is performed on the abnormal values in the experience data set.

[0060] The present application adopts the method of box plot to detect the collected abnormal values. The drawing of box plot relies on actual data, does not need to assume that the data is subject to a specific distribution form, does not have any restrictive requirements on data, and it only truly and intuitively shows the original appearance of data shape; on the other hand, the standard of box plot for judging abnormal values is based on quartiles and interquartile range, and the quartiles have a certain resistance, up to 25% of the data can become arbitrarily far without greatly disturbing the quartiles, so the abnormal values cannot affect this standard, and the result of identifying the abnormal values in the experience data set by the box plot is relatively objective.

[0061] The drawing method of box plot is: first find the upper edge, lower edge, median and two quartiles of a group of data; then, connect the two quartiles to draw a box; then connect the upper edge and the lower edge with the box, and the median is in the middle of the box. The corresponding upper and lower edge values can be obtained from the box plot, and the upper and lower edges are the boundaries of data distribution, and any data point higher than the upper edge or lower than the lower edge can be considered as an outlier or abnormal value.

[0062] In the actual normal operation process of the device, the data collected within a certain time is compared with the upper and lower edge values of the above box plot, if it is judged as an abnormal value, it is automatically excluded and counted, and does not participate in the judgment of operation protection, and the non-abnormal value continues to participate in the judgment of operation protection. If the abnormal values appear continuously for many times (the count value is too much) in the time period, it can be judged that the corresponding hardware has a problem, and the PLC system issues a warning.

[0063] S3, stable judgment.

[0064] The bus current value I1 of the PLC control system and the analog current value I2 accessed by the motor current transmitter are collected at fixed time intervals, if |I1-I2|<N, it is determined that the current data is stable, N is a preset current threshold, N can be set as 5% of the rated current of the motor, if |I1-I2|≥N occurs multiple times, it is determined that the current data is unstable, an alarm is issued, and the motor speed, current and torque data collected under the unstable state are discarded, and the data collection and data cleaning of steps S1-S2 are performed again under the stable state. The motor current is collected twice in the application, one set of data can verify the stability of the other set of collected current data, thereby improving the stability and reliability of the system.

[0065] S4, an empirical function model of the motor current and torque is respectively established based on the cleaned experience data set.

[0066] Specifically, the empirical function model of the current I x is defined as: I x ∈F(x)={K a *X1|X1∈U1}

[0067] The empirical function model of the torque T y is defined as: T y ∈F(y)={K b *X2|X2∈U2}

[0068] Wherein, K a , K b respectively represent the empirical proportion coefficient of the current and torque when different coal qualities are taken, X1 is any one element in the motor current experience data set U1, and X2 is any one element in the motor torque experience data set U2. The empirical function model F(x) of the current I x and the empirical function model F(y) of the torque T y can be regarded as a set, and the collected current or torque should theoretically be within the corresponding set.

[0069] S5, real-time collection of motor speed, current and torque data and data cleaning.

[0070] The motor generally has an acceleration time, and the real-time data should be collected after the motor acceleration time.

[0071] For the real-time collected motor current, the upper edge and the lower edge of the current box plot are obtained by drawing a current box plot based on the current experience data set, the data points higher than the upper edge or lower than the lower edge in the real-time collected current data are regarded as outliers or abnormal points, and the outliers or abnormal points are removed.

[0072] For the real-time collected motor torque, the upper edge and the lower edge of the torque box plot are obtained based on the torque empirical data set, the data points higher than the upper edge or lower than the lower edge in the real-time collected torque data are taken as outliers or abnormal points, and the outliers or abnormal points are eliminated.

[0073] S6, compare the cleaned real-time speed, current and torque data with the empirical function model, determine the operation of the screw conveyor, if the screw conveyor is abnormal, stop and alarm.

[0074] The control mode of the screw conveyor is constant speed control, generally according to the set motor speed, if the real-time speed is inconsistent with the set speed, it means that there is a problem, therefore, the present application is based on the real-time collected speed for preliminary determination, and then the current and torque data are used for comprehensive determination.

[0075] Step S6 specifically includes the following steps:

[0076] S61, obtain the set motor speed value of the screw conveyor, judge whether the real-time collected motor speed is consistent with the set motor speed value after the motor starts for a period of time (slightly greater than the acceleration ramp time), if not, determine that the screw conveyor is abnormal, stop and alarm; turn to step S52;

[0077] S62, if the real-time collected speed is consistent with the set speed value, judge whether the cleaned real-time current data conforms to the empirical function model of the current, and judge whether the cleaned real-time torque data conforms to the empirical function model of the torque, if the sum of the deviations of the cleaned real-time current data and the cleaned real-time torque data from the corresponding empirical function model is greater than the preset threshold, determine that the screw conveyor is abnormal, stop and alarm.

[0078] Specifically, the deviation of the current is defined as K1:

[0079] The deviation of the torque is defined as K2:

[0080] Wherein, i x is the real-time collected value of the motor current after cleaning at a fixed feeding speed, t y is the real-time collected value of the motor torque after cleaning at a fixed feeding speed, is the average value of the motor empirical function model F(x); is the average value of the motor torque empirical function model F(y);

[0081] The sum of the deviations of the cleaned real-time current data and the cleaned real-time torque data from the corresponding empirical function model is K:

[0082]

[0083] If the relationship K≥K n is always established in a continuous period of time, it is determined that the screw feeding and pipeline are abnormal, otherwise, they are normal, wherein K n is a fixed empirical value.

[0084] The present application fully utilizes the existing configuration to collect massive motor speed, current and torque data, and establishes an empirical function model of speed, motor current and torque, so as to determine the running condition of the screw conveyor through the comprehensive data of motor speed, current and torque, avoid the determination error caused by single type data, improve the accuracy of early warning, greatly improve the protection accuracy and stability of the screw conveyor, and the maintenance is simple during the later running period.

[0085] At present, the equipment adopting the method of the present application has been running for about 1 year, the detection accuracy of metal foreign matter jamming is basically 100%, and no false alarm event has occurred, so that the screw conveyor is truly and effectively protected.

[0086] Corresponding to the above method embodiment, the present application also provides a screw feeding and pipeline protection system of a screw ship unloader, which comprises:

[0087] A PLC control system: in field bus communication with frequency converters of driving motors of the screw ship unloader, and motor current transducer data is connected to an analog input module of the PLC control system, for collecting motor speed, current and torque data and generating an empirical data set during normal running of the screw conveyor, and collecting motor speed, current and torque data in real time;

[0088] A data processing module: for data cleaning of abnormal values of the empirical data set or the real-time collected motor speed, current and torque data, and establishing empirical function models of motor current and torque based on the cleaned empirical data set;

[0089] An abnormality judgment module: for comparing the real-time speed, current and torque data after data cleaning with the empirical function models, determining the running condition of the screw conveyor, and stopping and alarming if the screw conveyor is abnormal.

[0090] The above system embodiment and method embodiment are one-to-one corresponding, and the system embodiment can be referred to the method embodiment for brief description.

[0091] The present application also discloses an electronic device, comprising: at least one processor, at least one memory, a communication interface and a bus; wherein the processor, the memory and the communication interface complete communication with each other through the bus; the memory stores program instructions executable by the processor, and the processor calls the program instructions to implement the method of the present application.

[0092] The application further discloses a computer readable storage medium which stores computer instructions, and the computer instructions make the computer realize all or part of steps of the method in the embodiments of the application. The storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various storage program code mediums.

[0093] The system embodiments described above are only illustrative, wherein the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be distributed to multiple network units. A person of ordinary skill in the art can select part or all of the modules to achieve the purpose of the embodiments according to actual needs without creative labor.

[0094] The above only describes the preferred embodiments of the application and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A method for screw feeding and pipe protection of a screw unloader, characterized in that, The method includes: During normal operation of the screw conveyor, motor speed, current, and torque data are collected and an empirical dataset is generated. Data cleaning of outliers in empirical datasets; Empirical function models for motor current and torque were established based on the cleaned empirical dataset. Real-time acquisition of motor speed, current, and torque data, followed by data cleaning. The real-time speed, current and torque data after cleaning are compared with the empirical function model to determine the operating status of the screw conveyor. If the screw conveyor is operating abnormally, a shutdown alarm is triggered. During normal operation of the screw conveyor, the collection of motor speed, current, and torque data and the generation of an empirical dataset specifically include: The PLC control system communicates with the frequency converters of each drive motor of the screw unloader via fieldbus, and the data from each motor current transmitter is connected to the analog input module of the PLC control system. When the screw conveyor is normally picking up material, the current curves and torque curves of the material head drive motor, vertical screw drive motor and horizontal screw drive motor are recorded by the PLC control system according to the type of coal being picked up at the set motor speed. Based on the current curve and torque curve, the current database and torque database of the feed head drive motor, vertical screw drive motor and horizontal screw drive motor under different coal quality feed times at the set motor speed are obtained when the screw conveyor is running normally, and the corresponding empirical dataset is established. The process of comparing the real-time speed, current, and torque data after cleaning with the empirical function model to determine the operating status of the screw conveyor, and triggering a shutdown alarm if the screw conveyor is operating abnormally, specifically includes: The set motor speed value of the screw conveyor is obtained. After the motor has been running for a period of time, it is determined whether the real-time collected motor speed value is consistent with the set motor speed value. If they are inconsistent, the screw conveyor is determined to be operating abnormally and a shutdown alarm is triggered. If the real-time collected rotational speed is consistent with the set rotational speed value, it is determined whether the real-time current data after cleaning conforms to the empirical function model of current, and whether the real-time torque data after cleaning conforms to the empirical function model of torque. If the sum of the deviations between the real-time current data after cleaning and the real-time torque data after cleaning and the corresponding empirical function models is greater than the preset threshold, the screw conveyor is determined to be operating abnormally and a shutdown alarm is triggered.

2. The method for screw feeding and pipeline protection of a screw unloader according to claim 1, characterized in that, The specific steps for establishing empirical function models for motor current and torque based on the cleaned empirical dataset include: Current I x The empirical function model is: I x ∈F(x)={K a *X1|X1∈U1} Torque T y The empirical function model is: T y ∈F(y)={K b *X2|X2∈U2} Among them, K a K b X1 and X2 represent the empirical proportionality coefficients of current and torque when different coal qualities are taken, respectively. X1 is any element in the empirical dataset of motor current U1, and X2 is any element in the empirical dataset of motor torque U2.

3. The method for screw feeding and pipeline protection of a screw unloader according to claim 1, characterized in that, The real-time acquisition and data cleaning of motor speed, current, and torque data specifically includes: A current box plot is drawn based on the current empirical dataset. The upper and lower edges of the current box plot are obtained, and data points in the real-time collected current data that are higher than the upper edge or lower than the lower edge are removed. Based on the torque empirical dataset, a torque box plot is drawn, and the upper and lower edges of the torque box plot are obtained. Data points in the real-time collected torque data that are higher than the upper edge or lower than the lower edge are removed.

4. The method for screw feeding and pipeline protection of a screw unloader according to claim 1, characterized in that, If the sum of the deviations between the real-time current data and the real-time torque data after cleaning and the corresponding empirical function model exceeds a preset threshold, the screw conveyor is determined to be operating abnormally, and a shutdown alarm is triggered. Specifically, this includes: Define the current deviation as K1: Define the torque deviation as K2: Among them, i x The real-time measured value of the motor current after cleaning at a fixed material feeding speed is t. y This represents the real-time collected value of the motor torque after cleaning at a fixed material handling speed. This represents the average value of the empirical function model F(x) for the motor. F(y) represents the average value of the empirical function model of motor torque; The sum of the deviations between the real-time current data and the real-time torque data after cleaning and the corresponding empirical function model is K: If K≥K n If the relationship always holds true, then the screw feeder and pipeline are considered to be operating abnormally; otherwise, they are operating normally. In the formula, K... n It is a fixed empirical value.

5. The method for screw feeding and pipeline protection of a screw unloader according to claim 1, characterized in that, The method further includes: At fixed intervals, the PLC control system bus current value I1 and the analog current value I2 connected to the motor current transmitter are collected simultaneously. If |I1-I2|<N, the current data is considered stable, where N is a preset current threshold. If |I1-I2|≥N occurs multiple times, the data is considered unstable, an alarm is issued, and the motor speed, current, and torque data collected under unstable conditions are discarded.

6. A screw feeder and pipe protection system for a screw unloader employing the screw feeder and pipe protection method as described in any one of claims 1 to 5, characterized in that, The system includes: PLC control system: communicates with the frequency converters of each drive motor of the screw unloader via fieldbus, and the motor current transmitter data is connected to the analog input module of the PLC control system. It is used to collect motor speed, current and torque data and generate experience datasets during normal operation of the screw conveyor; and collect motor speed, current and torque data in real time. Data processing module: used to clean outliers in empirical datasets or real-time collected motor speed, current and torque data, and to establish empirical function models for motor current and torque based on the cleaned empirical datasets. Anomaly detection module: This module compares the real-time speed, current, and torque data after data cleaning with the empirical function model to determine the operating status of the screw conveyor. If the screw conveyor is operating abnormally, a shutdown alarm will be triggered.

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