Self-calibration method for multi-channel electric signal acquisition device

Abstract

The invention provides a self-calibration method for an electric signal multichannel acquisition device, which comprises the following steps of: calibrating each channel and a built-in reference source by using a high-precision calibrator before the device leaves a factory, and storing a source value of the reference source; starting calibration after the continuous operation time of the device reaches a calibration period; performing K-S test pairwise to judge the running state of each channel by using the distribution of measured values obtained by collecting the same reference source signal by each channel; combining the average value of the distribution of the measurement values of the normal channels with the source value of the reference source for outlier test, and further judging the state of the reference source; real-time online calibration is carried out on an abnormal component by using a normal reference source or normal multi-channel measurement value distribution, so that long-term operation stability, reliability and continuity of the electric signal multi-channel acquisition device are guaranteed, state information can be reported to a remote control terminal in time aiming at the condition that the reference source and most channels are abnormal, and the remote control terminal is protected. Manual calibration operation and maintenance work can be effectively carried out, and manpower and material resource losses are reduced.

Description

Technical Field

[0001] The present invention relates to the field of electric signal acquisition, and more specifically, to a self-calibration method for an electric signal multi-channel acquisition device. Background Art

[0002] The multi-channel electrical signal acquisition device includes a voltage acquisition device and a current acquisition device, which has been widely used in many fields such as electrical parameter measurement, electrical safety monitoring, and equipment status control, providing key data guarantee for the closed-loop regulation of smart grids. However, the multi-channel electrical signal acquisition device is often affected by many factors such as device aging, high temperature and humidity, and electromagnetic interference. When it runs for a long time without power outage, each channel is very likely to have unstable acquisition performance, error tolerance, and other faults. Therefore, it is necessary to calibrate each channel of the electrical signal acquisition device in a timely manner.

[0003] The current calibration methods of multi-channel electrical signal acquisition devices are divided into offline calibration and online calibration. Offline calibration requires the electrical signal acquisition device to be disconnected from the power grid before subsequent calibration. Usually, the acquisition device is disassembled from the site and sent back to the laboratory for manual calibration of each channel within a fixed period, or operation and maintenance personnel are dispatched to the site with a portable high-precision calibrator to carry out device calibration work. Because this method requires power off and disassembly, and lacks real-time status information of the acquisition device, offline calibration work may cause unnecessary waste of resources. Online calibration is to calibrate each channel using the reference source signal by building a high-precision reference source into the device at a fixed period. Although this method can be performed online, as the device runs longer, the reference source also faces problems such as device aging and performance degradation.

[0004] Both offline calibration and online calibration are unaware of the status information of each channel or reference source. When the performance of each channel and reference source is seriously degraded, if manual operation and maintenance are not arranged in time, serious accidents in safety monitoring, trade settlement, etc. may occur. Summary of the invention

[0005] In view of the technical problems existing in the prior art, the present invention provides a self-calibration method for an electrical signal multi-channel acquisition device. By building a reference source into the device and utilizing the distribution of measurement values ​​obtained by acquiring reference source signals from each channel, online self-calibration of abnormal channels or abnormal reference sources is achieved. At the same time, status judgment is completed and information is reported to a remote control terminal so that manual operation and maintenance can be carried out in a timely manner.

[0006] The present invention provides a self-calibration method for an electrical signal multi-channel acquisition device, comprising: Step S1: Before the multi-channel acquisition device leaves the factory, use a high-precision calibrator to calibrate each channel and the built-in reference source, and store the reference source value after calibration. , and set the self-calibration cycle of the multi-channel acquisition device , each channel is recorded as , is the number of channels, is a positive integer; Step S2: After the multi-channel acquisition device starts to operate normally, if the multi-channel acquisition device continuously operates for a period of time that reaches a self-calibration period, , then start the self-calibration process and enter step S3, otherwise continue to run; Step S3: synchronously collect the output signal of the reference source using each channel, and collect the output signal of the reference source using the acquisition time. Then the measured value distribution of each channel is obtained , the measured values ​​are distributed Perform KS test on each pair and determine the number of abnormal channels based on the test results ,like , then each channel If the operation status is normal, go to step S4, otherwise go to step S6; Step S4: Distribution of measured values ​​of each channel Calculate their average values , the average value With reference source value Combine and perform an outlier test, and determine the operating state of the reference source according to the test result. If the operating state of the reference source is normal, proceed to step S10, otherwise proceed to step S5; Step S5: Using the average value of the measured value distribution of each channel Calculate the calibration scale factor for the abnormal reference source , calibrate the abnormal reference source and enter step S10; Step S6: If the number of abnormal channels , then go to step S7, otherwise go to step S11, where The value is a fixed coefficient, satisfying and ; Step S7: Eliminate the measured value distribution of abnormal channels, and compare the average value of the measured value distribution of the remaining normal channels with the reference source value. Combine and perform an outlier test, and determine the operating state of the reference source according to the test result. If the operating state of the reference source is normal, proceed to step S8, otherwise proceed to step S9; Step S8: record the abnormal channel as , using the reference source value Calculate abnormal channels Calibration scale factor , for abnormal channels Perform calibration and proceed to step S10; Step S9: Utilize the remaining normal channels The mean of the distribution of measured values Calculate the calibration scale factor for the abnormal reference source and abnormal channels Calibration scale factor , , calibration scale factor based on abnormal reference source and abnormal channels Calibration scale factor , for abnormal reference sources and abnormal channels Perform calibration and proceed to step S10; Step S10: The multi-channel acquisition device exits the self-calibration process and continues to run, and enters step S2.

[0007] The present invention provides a self-calibration method for an electrical signal multi-channel acquisition device. By building a reference source into the device, using the distribution of measured values ​​obtained by each channel acquiring the same reference source signal, and performing a series of hypothesis tests and logical judgments, the operating status of each channel and the reference source can be determined, and normal information can be mined from the distribution of measured values ​​to achieve online self-calibration of abnormal channels or abnormal reference sources, effectively ensuring the long-term operating stability, reliability and continuity of the electrical signal multi-channel acquisition device; according to the operating status of each channel and the reference source in the device, relevant information is reported to the remote control terminal in a timely manner, so as to carry out manual operation and maintenance work in a timely and effective manner and reduce the loss of manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic flow chart of a self-calibration method for a multi-channel electrical signal acquisition device provided by the present invention; Figure 2 A schematic diagram of the structure of a self-calibration system for a multi-channel electrical signal acquisition device provided by the present invention; Figure 3 A diagram of KS test results during a calibration process of a voltage signal acquisition device provided by the present invention; In the accompanying drawings, the device names represented by the reference numerals are as follows: 1. Built-in reference source, 2. Acquisition channel, 3. Clock source module, 4. Self-calibration process start switch, 5. State determination module, 6. KS inspection submodule, 7. Outlier inspection submodule, 8. Data calculation submodule, 9. Calibration module, 10. Proportional calibration coefficient of acquisition channel, 11. Proportional calibration coefficient of abnormal reference source, 12. Information reporting module, 13. Remote control terminal, 14. Wireless transmission channel. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments 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 in 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. In addition, the technical features in the various embodiments or single embodiments provided by the present invention can be arbitrarily combined with each other to form a feasible technical solution. This combination is not subject to the constraints of the sequence of steps and / or the structural composition mode, but must be based on the ability of ordinary technicians in this field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0010] See also Figure 1 , a flowchart of a self-calibration method for a multi-channel electrical signal acquisition device provided by an embodiment of the present invention includes: Step S1: Before the multi-channel acquisition device leaves the factory, use a high-precision calibrator to calibrate each channel and the built-in reference source, and store the reference source value after calibration. , and set the self-calibration cycle of the multi-channel acquisition device .

[0011] Specifically, before the multi-channel acquisition device leaves the factory, the distribution of the measured values ​​obtained by each channel of the same multi-channel acquisition device after calibration by a high-precision calibrator when acquiring the same signal follows the same statistical distribution, and each channel is denoted as , is the number of channels, Is a positive integer.

[0012] Step S2: After the multi-channel acquisition device starts to operate normally, if the multi-channel acquisition device continuously operates for a period of time that reaches a self-calibration period, , then start the self-calibration process and enter step S3, otherwise continue to run.

[0013] Among them, in step S2, the continuous operation time of the multi-channel acquisition device is determined by the time signal of the device clock source. When the device starts to operate normally, the current time signal of the device clock source is stored. , when the device clock source time signal arrives The self-calibration process starts when

[0014] Step S3: synchronously collect the output signal of the reference source using each channel, and collect the output signal of the reference source using the acquisition time. Then the measured value distribution of each channel is obtained , the measured values ​​are distributed Perform KS test on each pair and determine the number of abnormal channels based on the test results ,like , then each channel If the operation status is normal, go to step S4; otherwise, go to step S6.

[0015] Specifically, the measured value distribution of any two channels in step S3 is The specific steps for conducting the KS test are as follows: Step S31: according to the distribution Calculate their empirical distribution functions respectively , where is the statistical distribution sample value; Step S32: Calculate two empirical distribution functions Maximum separation distance , where represents the maximum difference calculation function; Step S33, propose KS test hypothesis: H0 (measurement value distribution from the same statistical distribution), H1 (measurement distribution from different statistical distributions); Step S34: If , then reject H0, otherwise accept H0, where is the significance level, , The measured values ​​of the two channels are distributed separately The number of samples.

[0016] Among all the channels in the device, if a channel With at least After the KS test, the channels belong to different statistical distributions. is an abnormal channel, where is a positive integer, , The larger the value, the more accurate the channel abnormality judgment result.

[0017] Identify all abnormal channels in the multi-channel acquisition device through KS test and count the number of abnormal channels .

[0018] Step S4: Distribution of measured values ​​of each channel Calculate their average values , the average value With reference source value An outlier test is combined and performed, and the operating state of the reference source is determined according to the test result. If the operating state of the reference source is normal, the process proceeds to step S10, otherwise, the process proceeds to step S5.

[0019] Specifically, if the number of abnormal channels , then each channel The operating status is normal. Due to the distribution of measured values ​​of each channel is a sequence value, then according to Calculate the corresponding average values .

[0020] The average value of the measured value distribution of the normal channel Combined with the reference source value M, the local outlier factor of the reference source value is calculated Perform outlier test if , then the operating state of the reference source is determined to be abnormal, otherwise the operating state of the reference source is determined to be normal, wherein, is a positive number, , The larger it is, the more accurate the result of the reference source anomaly judgment is.

[0021] It should be noted that outlier detection is a relatively mature technology. Outliers are data points that are obviously abnormal in the observed data set, or in other words, the data distribution of outliers is different from the overall distribution of the data set. The purpose of outlier detection is to detect data points that are significantly different from normal data, and then further process them according to specific problems.

[0022] The outlier detection algorithms mainly include methods based on statistics, clustering, classification, information theory, distance, density, etc. The local outlier factor algorithm is also a relatively mature algorithm and will not be explained here.

[0023] Step S5: Using the average value of the measured value distribution of each channel Calculate the calibration scale factor for the abnormal reference source , calibrate the abnormal reference source and enter step S10.

[0024] Specifically, if the outlier test finds that the operating state of the reference source is abnormal, then the average value of the measured value distribution of each channel is calculated. Calculate the calibration scale factor for the abnormal reference source , calibration scale factor based on abnormal reference source Calibrate the abnormal reference source, and the reference source value after calibration .

[0025] Step S6: If the number of abnormal channels , then go to step S7, otherwise go to step S11, where The value is a fixed coefficient, satisfying and , The smaller the value, the higher the reliability requirement of the device self-calibration.

[0026] Specifically, if the number of abnormal channels counted ≠0, it means there are abnormal channels. If the number of abnormal channels is , that is, there are a few abnormal channels, then the few abnormal channels can be calibrated, and after calibration, the multi-channel acquisition device can continue to be used. If most of the channels in the device are abnormal, manual maintenance is required, and online calibration is no longer required.

[0027] Therefore, when the number of abnormal channels is , go to step S7 to calibrate the abnormal channel.

[0028] Step S7: Eliminate the measured value distribution of abnormal channels, and compare the average value of the measured value distribution of the remaining normal channels with the reference source value. An outlier test is combined and performed, and the operating state of the reference source is determined according to the test result. If the operating state of the reference source is normal, the process proceeds to step S8, otherwise, the process proceeds to step S9.

[0029] Specifically, if there is an abnormal channel, the measurement value of the abnormal channel on the reference source signal is eliminated, and the remaining normal channels are used to perform an outlier test on the reference source value M to determine whether the operating status of the reference source is abnormal.

[0030] Step S8: record the abnormal channel as , using the reference source value Calculate abnormal channels Calibration scale factor , for abnormal channels Perform calibration and proceed to step S10.

[0031] Specifically, if there are a small number of abnormal channels and the operating state of the reference source is normal, the calibration ratio coefficient of the abnormal channel is calculated using the reference source value. , abnormal channel after calibration The measured value is '= × ;in, Abnormal channel The average value of Abnormal channel Collect the measured value of the reference source signal, ' is the abnormal channel after calibration Acquire measurements of the reference source signal.

[0032] Step S9: Utilize the remaining normal channels The mean of the distribution of measured values Calculate the calibration scale factor for the abnormal reference source and abnormal channels Calibration scale factor , , calibration scale factor based on abnormal reference source and abnormal channels Calibration scale factor , for abnormal reference sources and abnormal channels Perform calibration and proceed to step S10.

[0033] Specifically, if there are a small number of abnormal channels and the operating state of the reference source is also abnormal, the calibration ratio coefficient of the abnormal reference source is calculated using the measurement value distribution of the remaining normal channels. and abnormal channels Calibration scale factor .in: ; ; The reference source value after calibration is , and the abnormal channel after calibration The measured values ​​are: '= × ; in, Abnormal channel The average value of Abnormal channel Collect the measured value of the reference source signal, ' is the abnormal channel after calibration Acquire measurements of the reference source signal.

[0034] Step S10: The multi-channel acquisition device exits the self-calibration process and continues to run, and enters step S2.

[0035] Specifically, channel steps S2 to S9 implement online calibration of each channel and the reference source according to the state of each channel and the operating state of the reference source, thereby completing the calibration process.

[0036] It should be noted that when there are a small number of abnormal channels and the reference source is abnormal, a warning event of abnormal measurement performance of the multi-channel acquisition device is reported, and manual calibration and maintenance work needs to be carried out in a short period of time. However, if most or even all channels are abnormal and the reference source is also abnormal, it is necessary to report the abnormal measurement performance event of the multi-channel acquisition device, and manual calibration and maintenance work needs to be carried out immediately.

[0037] See also Figure 2, a structural diagram of a self-calibration system for an electrical signal multi-channel acquisition device provided by an embodiment of the present invention includes a clock source module 3, a state determination module 5, a calibration module 9, an information reporting module 12, and a remote control terminal 13.

[0038] The clock source module 3 is used to provide a clock signal to the self-calibration system, store and record the continuous operation time of the device, and control the self-calibration process start switch 4 of the multi-channel acquisition device; the state judgment module 5 performs step-by-step inspection and logical judgment according to the distribution of the measured values ​​of the signal output of the built-in reference source 1 collected by each acquisition channel 2, and then determines the operation status of each acquisition channel 2 and the built-in reference source 1, provides calibration guidance information to the calibration module 9, and provides the status information of each acquisition channel 2 and the built-in reference source 1 to the information reporting module 12, which specifically includes a KS inspection submodule 6, an outlier inspection submodule 7, and a data calculation submodule 8; the calibration module 9 calculates the calibration proportional coefficient 10 of the abnormal channel or the calibration proportional coefficient 11 of the abnormal reference source according to the calibration guidance information provided by the state judgment module 5, and transmits it to each acquisition channel 2 or the built-in reference source 1 to complete the calibration; the information reporting module 12 transmits the status information of each acquisition channel 2 and the built-in reference source 1 to the remote control terminal 13 through the wireless transmission channel 14; the remote control terminal 13 guides the manual calibration operation and maintenance work according to the status information of each acquisition channel 2 and the built-in reference source 1.

[0039] The following is a detailed description of the steps of the self-calibration method for the above-mentioned multi-channel acquisition device of electrical signals using a specific calibration example: Step S1: For a 16-channel voltage signal acquisition device, use a high-precision voltage calibrator to calibrate each channel and the built-in voltage reference source before it leaves the factory, and store the reference source value after calibration. , and set the device self-calibration cycle Specifically, the distribution of the measured values ​​obtained by each channel of the same multi-channel acquisition device calibrated by a high-precision calibrator when acquiring the same signal follows the same normal distribution, and each channel is denoted as .

[0040] Step S2: When the device continuously runs for a period of time equal to the calibration period , start the self-calibration process and enter step S3.

[0041] Step S3: synchronously collect the output signal of the reference source using each channel, and collect the output signal of the reference source using the acquisition time. (The sampling rate is 10000) and then the measured value of each channel and the frequency density distribution can be obtained respectively .

[0042] Distribute the measured values Perform KS test on each pair and determine the number of abnormal channels based on the test results =2, the fault channel is , , where the KS test results are shown in Figure 3 ,because , proceed to step S6.

[0043] Step S6: Due to abnormal channel number ( Take 0.15), then go to step S7.

[0044] Step S7: Eliminate abnormal channels , The measured value distribution of the remaining normal channels is the average value of the measured value distribution With reference source value Merge, then perform outlier test, according to the test results ( Taking 1.20) it can be determined that the reference source is in normal operating state, and the process goes to step S8.

[0046] Step S8: abnormal channel is , , and the average values ​​of their measured value distributions are , , using the reference source value Calculate abnormal channels , Calibration scale factor , And the calibration is completed, and then the process goes to step S10.

[0047] Step S10: The multi-channel device exits the self-calibration process and continues to run, and enters step S2.

[0048] The present invention provides a self-calibration method for an electrical signal multi-channel acquisition device. By building a reference source into the device, using the distribution of measured values ​​obtained by each channel acquiring the same reference source signal, and performing a series of hypothesis tests and logical judgments, the operating status of each channel and the reference source can be determined, and normal information can be mined from the distribution of measured values ​​to achieve online self-calibration of abnormal channels or abnormal reference sources, effectively ensuring the long-term operating stability, reliability and continuity of the electrical signal multi-channel acquisition device; according to the operating status of each channel and the reference source in the device, relevant information is reported to the remote control terminal in a timely manner, so as to carry out manual operation and maintenance work in a timely and effective manner and reduce the loss of manpower and material resources.

[0049] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0050] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0051] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0052] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0053] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0054] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A self-calibration method for a multi-channel electrical signal acquisition device, characterized in that: include: Step S1: Before the multi-channel acquisition device leaves the factory, use a high-precision calibrator to calibrate each channel and the built-in reference source, and store the reference source value after calibration. , and set the self-calibration cycle of the multi-channel acquisition device , each channel is recorded as , is the number of channels, is a positive integer; Step S2: After the multi-channel acquisition device starts to operate normally, if the multi-channel acquisition device continuously operates for a period of time that reaches a self-calibration period, , then start the self-calibration process and enter step S3, otherwise continue to run; Step S3: synchronously collect the output signal of the reference source using each channel, and collect the output signal of the reference source using the acquisition time. Then the measured value distribution of each channel is obtained , the measured values ​​are distributed Perform KS test on each pair and determine the number of abnormal channels based on the test results ,like , then each channel If the operation status is normal, go to step S4, otherwise go to step S6; Step S4: Distribution of measured values ​​of each channel Calculate their average values , the average value With reference source value Combine and perform an outlier test, and determine the operating state of the reference source according to the test result. If the operating state of the reference source is normal, proceed to step S10, otherwise proceed to step S5; Step S5: Using the average value of the measured value distribution of each channel Calculate the calibration scale factor for the abnormal reference source , calibrate the abnormal reference source and enter step S10; Step S6: If the number of abnormal channels , then go to step S7, otherwise go to step S11, where The value is a fixed coefficient, satisfying and ; Step S7: Eliminate the measured value distribution of abnormal channels, and compare the average value of the measured value distribution of the remaining normal channels with the reference source value. Combine and perform an outlier test, and determine the operating state of the reference source according to the test result. If the operating state of the reference source is normal, proceed to step S8, otherwise proceed to step S9; Step S8: record the abnormal channel as , using the reference source value Calculate abnormal channels Calibration scale factor , for abnormal channels Perform calibration and proceed to step S10; Step S9: Utilize the remaining normal channels The mean of the distribution of measured values Calculate the calibration scale factor for the abnormal reference source and abnormal channels Calibration scale factor , , calibration scale factor based on abnormal reference source and abnormal channels Calibration scale factor , for abnormal reference sources and abnormal channels Perform calibration and proceed to step S10; Step S10: The multi-channel acquisition device exits the self-calibration process and continues to run, and enters step S2.

2. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 1, characterized in that: In the step S1, the distribution of measurement values ​​obtained by each channel of the multi-channel acquisition device after being calibrated by the high-precision calibrator when acquiring the same reference source signal follows the same statistical distribution.

3. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 1, characterized in that: In step S2, the continuous operation time of the multi-channel acquisition device is determined by the time signal of the multi-channel acquisition device clock source. When the multi-channel acquisition device starts to operate normally, the current time signal of the multi-channel acquisition device clock source is stored. , when the clock source signal of the multi-channel acquisition device reaches , starts the self-calibration process.

4. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 2, characterized in that: In step S3, the measured value distribution KS test is performed on both pairs, including: Distribution of measured values ​​for any two channels and , , according to the distribution of measured values and Calculate their empirical distribution functions respectively and ,in, is the statistical distribution sample value; Compute two empirical distribution functions and Maximum separation distance , where represents the maximum difference calculation function; Propose KS test hypothesis: H0 is the distribution of two measured values and From the same statistical distribution, H1 is the distribution of two measurements and from different statistical distributions; if , then reject H0, otherwise accept H0, where is the significance level, , The measured value distribution of the two channels is and The number of samples.

5. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 4, characterized in that: In step S3, the measured value distribution Perform KS test on each pair and determine the number of abnormal channels based on the test results ,include: If the channel With at least After the KS test, the channels belong to different statistical distributions. is an abnormal channel, where , is a positive integer, ; Count the number of abnormal channels .

6. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 1, characterized in that: The outlier test in step S4 and step S7 includes: The average value of the measured value distribution of the normal channel is combined with the reference source value M, and the local outlier factor of the reference source value is calculated. Perform outlier test if , then the operating state of the reference source is determined to be abnormal, otherwise the operating state of the reference source is determined to be normal, wherein, is a positive number, .

7. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 1, characterized in that: The calibration scale factor of the abnormal reference source in step S5 , calibration scale factor based on abnormal reference source Calibrate the abnormal reference source, and the reference source value after calibration .

8. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 1, characterized in that: In step S8, the reference source value is used Calculate abnormal channels Calibration scale factor , for abnormal channels Perform calibration, including: ； Abnormal channel after calibration The measured values ​​are: '= × ； in, Abnormal channel The average value of Abnormal channel Collect the measured value of the reference source signal, ' is the abnormal channel after calibration Acquire measurements of the reference source signal.

9. The self-calibration method for a multi-channel electrical signal acquisition device according to claim 1, characterized in that: In step S9, the remaining normal channels are used The mean of the distribution of measured values Calculate the calibration scale factor for the abnormal reference source and abnormal channels Calibration scale factor ,include: ； ； The reference source value after calibration is , and the abnormal channel after calibration The measured values ​​are: '= × ； in, Abnormal channel The average value of Abnormal channel Collect the measured value of the reference source signal, ' is the abnormal channel after calibration Acquire measurements of the reference source signal.

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