A method for calibrating a measurement device loop

Abstract

The present invention provides a calibration method for a measurement device loop in the field of power electronics technology, including: Step S10, creating a configuration file for each test device respectively and creating a voltage compensation table; Step S20, based on the configuration file, obtaining the test channels and test ranges of the test device to be calibrated; Step S30, selecting two calibration values from each test range of each test channel and setting the alarm limit values of each calibration value; Step S40, controlling the test device to output voltage based on the calibration values and collecting the first output voltage through a voltage sampling board; Step S50, filtering each first voltage by using the mean filtering method to obtain the second voltage and verifying the second voltage based on the alarm limit values; Step S60, obtaining the voltage compensation formula for each test range based on the second voltage, the calibration values and the voltage compensation table, and calibrating the measurement device loop based on the voltage compensation formula. The advantages of the present invention are: greatly improving the calibration accuracy of the measurement device loop.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly to a method for calibrating a measurement device loop. Background Art

[0002] With the rapid development of new energy, the demand for lithium batteries is increasing day by day. After the production of lithium batteries, in order to ensure the safety and durability of use, a series of tests are required, and relevant test equipment is needed to collect data such as voltage values and current values.

[0003] The test equipment needs to be connected to the probe through a cable so that the probe can be connected to the pole of the lithium battery. No matter what material the cable is, there is a certain line resistance (internal resistance). The longer the cable and the greater the current, the greater the voltage loaded on the cable, which will lead to deviation in the test results. Therefore, it is necessary to calibrate the loop (test loop) of the test equipment to improve the test accuracy.

[0004] However, the traditional calibration only collects the voltage value once through a voltmeter and then performs conversion compensation based on the collected voltage value. The considered dimension is too single and one-sided, making the calibration result unsatisfactory.

[0005] Therefore, how to provide a method for calibrating a measurement device loop to improve the calibration accuracy of the measurement device loop has become an urgent technical problem to be solved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for calibrating a measurement device loop to improve the calibration accuracy of the measurement device loop.

[0007] The present invention is implemented as follows: A method for calibrating a measurement device loop includes:

[0008] Step S10: Create a configuration file for each test device and create a voltage compensation table;

[0009] Step S20: Based on the configuration file, obtain the test channels and test ranges of the test device to be calibrated;

[0010] Step S30: Select two calibration values from each test range of each test channel and set the alarm limit values for each calibration value;

[0011] Step S40: Control the test device to output voltage based on the calibration value and collect the output first voltage through a voltage sampling board;

[0012] Step S50: Filter each first voltage by using the mean filtering method to obtain a second voltage, and verify the second voltage based on the alarm limit value;

[0013] Step S60: Obtain the voltage compensation formula for each test gear based on the second voltage, the calibration value, and the voltage compensation table, and calibrate the measurement device loop based on the voltage compensation formula.

[0014] Further, in the step S10, the configuration file carries at least the MAC address, the test channel, and the test gear corresponding to the test channel.

[0015] The configuration file is in JSON format and carries the first MD5 value calculated based on the MD5 algorithm.

[0016] Further, in the step S10, the voltage compensation table includes at least the one-to-one correspondence between the actual voltage, the measured voltage, the ambient temperature, and the voltage compensation value; the voltage compensation value = actual voltage - measured voltage.

[0017] Further, the step S20 specifically includes:

[0018] Step S21: Obtain the configuration file, and use the first MD5 value to verify the configuration file. If the verification passes, proceed to step S22; if the verification fails, end the process and give an alarm prompt.

[0019] Step S22: Obtain the MAC address of the test device to be calibrated, and determine whether the MAC address is consistent with the MAC address carried in the configuration file. If so, obtain the test channel and the test gear of the test device to be calibrated through the configuration file; if not, end the process and give an alarm prompt.

[0020] Further, in the step S30, the alarm limit values include the first alarm upper limit value, the second alarm upper limit value, the first alarm lower limit value, and the second alarm lower limit value.

[0021] The second alarm upper limit value > the first alarm upper limit value > the calibration value > the first alarm lower limit value > the second alarm lower limit value.

[0022] Further, the step S40 is specifically:

[0023] Set a voltage sampling frequency and a voltage sampling number.

[0024] Based on the two calibration values, respectively control the test device to output voltage, and collect each first voltage output by the voltage sampling board at the voltage sampling frequency and the voltage sampling number.

[0025] Further, the step S50 specifically includes:

[0026] Step S51: Set a quantity threshold n, calculate the average value of the first n first voltages as the value of the nth first voltage; then calculate the average value of the second to n+1th first voltages as the value of the n+1th first voltage, until all the first voltages are traversed, and take the last calculated average value as the second voltage;

[0027] Step S52: Determine whether the second voltage is greater than the first alarm upper limit value or less than the first alarm lower limit value. If so, proceed to step S53; if not, the verification passes, and proceed to step S60;

[0028] Step S53: Determine whether the second voltage is greater than the second alarm upper limit value or less than the second alarm lower limit value. If so, the calibration fails and the calibration stops; if not, proceed to step S54;

[0029] Step S54: Pop up a window to prompt whether to continue calibration, and determine whether a continue calibration instruction is received. If so, proceed to step S60; if not, stop the calibration.

[0030] Further, the step S60 specifically includes:

[0031] Step S61: Create a linear regression formula: y = ax + b;

[0032] Replace the two second voltages with x in the linear regression formula respectively, and replace the calibration value corresponding to the second voltage with y in the linear regression formula, and then calculate the values of a and b; both a and b represent voltage relationship coefficients;

[0033] Step S62: Obtain the current ambient temperature, and match the voltage compensation value co from the voltage compensation table for the ambient temperature and the second voltage, and then obtain the voltage compensation formula for each test gear:

[0034] y = ax + b + co;

[0035] Step S63: Obtain the MAC address of the test device to be calibrated, calculate the second MD5 value by using the MD5 algorithm for the MAC address and the voltage compensation formula, package the MAC address, the voltage compensation formula and the second MD5 value into a calibration file in JSON format and store it, and use the calibration file to calibrate the measurement device loop.

[0036] Further, it also includes:

[0037] Step S70: Use the 6Sigma algorithm to analyze each second voltage, and then update the alarm limit value.

[0038] The advantages of the present invention are:

[0039] 1. By calibrating each test gear for different test channels respectively, high-speed sampling of the voltage output by the test equipment is performed using the set voltage sampling frequency and the number of voltage samplings to obtain the first voltage. The mean filtering method is used to filter each first voltage to eliminate outliers, and the second voltage is calibrated based on the set alarm limit value, avoiding calibration in the case where there is an obvious abnormality in the loop, resulting in an incorrect voltage compensation formula obtained. By creating a voltage compensation table and incorporating the ambient temperature into the calibration parameters, that is, fully considering the influence of temperature on voltage, five measures are taken before and after, and finally the accuracy of the loop calibration of the measuring equipment is greatly improved.

[0040] 2. By using the 6Sigma algorithm and dynamically updating the alarm limit value of the second voltage, the accuracy of the loop calibration of the measuring equipment is further improved.

[0041] 3. By calculating the MD5 of the configuration file and the calibration file, the integrity of the configuration file and the calibration file can be effectively verified, and it can be effectively judged whether the configuration file and the calibration file have been tampered with, thereby greatly improving the security of the loop calibration of the measuring equipment. Description of the Drawings

[0042] The present invention will be further described below with reference to the accompanying drawings in conjunction with embodiments.

[0043] Figure 1 It is a flowchart of a method for calibrating a loop of a measuring device according to the present invention. Detailed Embodiments

[0044] The technical solution in the embodiments of the present application has the following general idea: Calibrate each test gear for different test channels respectively, perform high-speed sampling of the voltage output by the test equipment using the set voltage sampling frequency, use the mean filtering method to eliminate outliers, calibrate the second voltage based on the alarm limit value, and avoid calibration in the case where there is an obvious abnormality in the loop. By incorporating the ambient temperature into the calibration parameters, the accuracy of the loop calibration of the measuring equipment is improved.

[0045] Please refer to Figure 1 As shown, a preferred embodiment of a method for calibrating a loop of a measuring device according to the present invention includes:

[0046] Step S10: Create a configuration file for each test equipment respectively, and create a voltage compensation table;

[0047] Step S20: Based on the configuration file, obtain the test channels and test gears of the test equipment to be calibrated;

[0048] Step S30: Select two calibration values from each test gear of each test channel respectively, and set the alarm limit values of each calibration value;

[0049] For example, if the test equipment has two test channels, namely channel1 and channel2, both channel1 and channel2 include three test ranges, namely (0 - 10), (10 - 20), and (20 - 100). Two calibration values are selected from (0 - 10) of channel1, which are 4V and 8V respectively; the first alarm upper limit value, the second alarm upper limit value, the first alarm lower limit value, and the second alarm lower limit value corresponding to 4V are 4.1V, 4.2V, 3.9V, and 3.8V respectively; the first alarm upper limit value, the second alarm upper limit value, the first alarm lower limit value, and the second alarm lower limit value corresponding to 8V are 8.2V, 8.3V, 7.8V, and 7.7V respectively.

[0050] Step S40: Control the test equipment to output voltage based on the calibration value, and collect the first output voltage through the voltage sampling board.

[0051] Step S50: Filter each of the first voltages using the mean filtering method to obtain the second voltage, and verify the second voltage based on the alarm limit values.

[0052] Step S60: Obtain the voltage compensation formula (calibration formula) for each test range based on the second voltage, the calibration value, and the voltage compensation table, and calibrate the measurement equipment loop based on the voltage compensation formula.

[0053] In the step S10, the configuration file carries at least the MAC address, the test channel, and the test range corresponding to the test channel.

[0054] The configuration file is in JSON format and carries the first MD5 value calculated based on the MD5 algorithm.

[0055] In the step S10, the voltage compensation table includes at least the one-to-one correspondence between the actual voltage (source voltage), the measured voltage, the ambient temperature, and the voltage compensation value; the voltage compensation value = actual voltage - measured voltage. The voltage compensation table is used to record the voltage change curve with temperature.

[0056] An example of the voltage compensation table is as follows:

[0057]

[0058]

[0059] The step S20 specifically includes:

[0060] Step S21: Obtain the configuration file, verify the configuration file using the first MD5 value. If the verification passes, proceed to step S22; if the verification fails, end the process and give an alarm prompt.

[0061] Step S22: Obtain the MAC address of the test device to be calibrated, and determine whether the MAC address is consistent with the MAC address carried in the configuration file. If so, obtain the test channel and test gear of the test device to be calibrated through the configuration file; if not, end the process and give an alarm prompt.

[0062] In the step S30, the alarm limits include a first alarm upper limit value, a second alarm upper limit value, a first alarm lower limit value, and a second alarm lower limit value;

[0063] The second alarm upper limit value > the first alarm upper limit value > the calibration value > the first alarm lower limit value > the second alarm lower limit value.

[0064] The step S40 is specifically as follows:

[0065] Set a voltage sampling frequency and a voltage sampling number; the voltage sampling frequency is preferably 1000HZ, and the voltage sampling number is preferably 1000;

[0066] Based on the two calibration values, respectively control the test device to output voltage, and collect each first voltage output by the voltage sampling board at the voltage sampling frequency and voltage sampling number.

[0067] The step S50 specifically includes:

[0068] Step S51: Set a quantity threshold n, calculate the average value of the first n first voltages as the value of the nth first voltage; then calculate the average value of the first voltages from the 2nd to the (n + 1)th as the value of the (n + 1)th first voltage, until all the first voltages are traversed, and take the finally calculated average value as the second voltage;

[0069] For example, when the quantity threshold n is 100 and the voltage sampling number is 1000, first calculate the average value of the first 100 first voltages as the value of the 100th first voltage, then calculate the average value of the first voltages from the 2nd to the 101st as the value of the 101st first voltage, and so on;

[0070] Step S52: Determine whether the second voltage is greater than the first alarm upper limit value or less than the first alarm lower limit value. If so, enter step S53; if not, the verification passes and enter step S60;

[0071] Step S53: Determine whether the second voltage is greater than the second alarm upper limit value or less than the second alarm lower limit value. If so, the verification fails and the calibration stops; if not, enter step S54;

[0072] Step S54: Pop up a window to prompt whether to continue calibration, and determine whether a continue calibration instruction is received. If yes, go to step S60; if no, stop calibration.

[0073] For example, after using 4V to control the test equipment to output voltage and collecting the second voltage, if the value of the second voltage is 4.05V, which is less than the first warning upper limit value, the calibration passes; if the value of the second voltage is 4.15V, which is between the first warning upper limit value and the second warning upper limit value, a window will pop up to prompt whether to continue calibration; if the value of the second voltage is 4.3V, which is greater than the second warning upper limit value, stop calibration.

[0074] The specific steps of step S60 include:

[0075] Step S61: Create a linear regression formula: y = ax + b;

[0076] Replace x in the linear regression formula with the two second voltages respectively, and replace y in the linear regression formula with the calibration value corresponding to the second voltage, and then calculate the values of a and b; both a and b represent voltage relationship coefficients;

[0077] Step S62: Obtain the current ambient temperature, and match the voltage compensation value co from the voltage compensation table according to the ambient temperature and the second voltage, and then obtain the voltage compensation formula for each test gear:

[0078] y = ax + b + co;

[0079] Step S63: Obtain the MAC address of the test equipment to be calibrated, calculate the second MD5 value by using the MD5 algorithm for the MAC address and the voltage compensation formula, package the MAC address, the voltage compensation formula and the second MD5 value into a calibration file in JSON format and store it, and use the calibration file to calibrate the measurement equipment loop. The MAC address is used to match the test equipment, the configuration file and the calibration file.

[0080] An example of the calibration file is as follows:

[0081]

[0082]

[0083]

[0084] It also includes:

[0085] Step S70: Use the 6Sigma algorithm to analyze each of the second voltages, and then update the warning limit values.

[0086] In summary, the advantages of the present invention are:

[0087] 1. By calibrating each test gear for different test channels respectively, high-speed sampling of the voltage output by the test equipment is performed using the set voltage sampling frequency and the number of voltage samplings to obtain the first voltage. The mean filtering method is used to filter each first voltage to eliminate outliers. The second voltage is calibrated based on the set alarm limit value to avoid calibration when there are obvious abnormalities in the loop, resulting in an incorrect voltage compensation formula. By creating a voltage compensation table and incorporating the ambient temperature into the calibration parameters, that is, fully considering the influence of temperature on voltage, five measures are taken before and after, and finally the accuracy of the loop calibration of the measuring equipment is greatly improved.

[0088] 2. By using the 6Sigma algorithm and dynamically updating the alarm limit value of the second voltage, the accuracy of the loop calibration of the measuring equipment is further improved.

[0089] 3. By calculating the MD5 of the configuration file and the calibration file, the integrity of the configuration file and the calibration file can be effectively verified, and it can be effectively judged whether the configuration file and the calibration file have been tampered with, thereby greatly improving the security of the loop calibration of the measuring equipment.

[0090] Although the specific implementation manners of the present invention are described above, those skilled in the art of this technology should understand that the specific embodiments we described are illustrative rather than used to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered by the scope protected by the claims of the present invention.

Claims

1. A calibration method for a measurement device loop, characterized in that: It includes: Step S10: Create a configuration file for each test device respectively, and create a voltage compensation table; The voltage compensation table at least includes the one-to-one correspondence relationship of actual voltage, measured voltage, ambient temperature, and voltage compensation value; voltage compensation value = actual voltage - measured voltage; Step S20: Based on the configuration file, obtain the test channels and test gears of the test device to be calibrated; Step S30: Select two calibration values from each test gear of each test channel respectively, and set the alarm limit values for each calibration value; Step S40: Control the test device to output voltage based on the calibration value, and collect the first output voltage through a voltage sampling board; Step S50: Use the mean filtering method to filter each first voltage to obtain a second voltage, and verify the second voltage based on the alarm limit value; Step S60: Obtain the voltage compensation formula for each test gear based on the second voltage, calibration value, and voltage compensation table, and calibrate the measurement device loop based on the voltage compensation formula.

2. A calibration method for a measurement device loop according to claim 1, characterized in that: In step S10, the configuration file at least carries the MAC address, test channels, and test gears corresponding to the test channels; The configuration file is in JSON format and carries the first MD5 value calculated based on the MD5 algorithm.

3. A calibration method for a measurement device loop according to claim 2, characterized in that: Step S20 specifically includes: Step S21: Obtain the configuration file, verify the configuration file using the first MD5 value. If the verification passes, proceed to step S22; if the verification fails, end the process and give an alarm prompt; Step S22: Obtain the MAC address of the test device to be calibrated, and determine whether the MAC address is consistent with the MAC address carried in the configuration file. If so, obtain the test channels and test gears of the test device to be calibrated through the configuration file; if not, end the process and give an alarm prompt.

4. A calibration method for a measurement device loop according to claim 1, characterized in that: In step S30, the alarm limit values include a first alarm upper limit value, a second alarm upper limit value, a first alarm lower limit value, and a second alarm lower limit value; Second alarm upper limit value > first alarm upper limit value > calibration value > first alarm lower limit value > second alarm lower limit value.

5. A calibration method for a measurement device loop according to claim 1, characterized in that: Step S40 is specifically: Set a voltage sampling frequency and a voltage sampling number; Based on the two calibration values, control the test device to output voltage respectively, and collect each first output voltage through the voltage sampling board at the voltage sampling frequency and voltage sampling number.

6. A calibration method for a measurement device loop according to claim 4, characterized in that: Step S50 specifically includes: Step S51: Set a quantity threshold n, calculate the average value of the first n first voltages as the value of the nth first voltage; then calculate the average value of the first voltages from the 2nd to the (n + 1)th as the value of the (n + 1)th first voltage, until all the first voltages are traversed, and take the last calculated average value as the second voltage. Step S52: Determine whether the second voltage is greater than the first alarm upper limit value or less than the first alarm lower limit value. If so, proceed to step S53; if not, the verification passes, and proceed to step S60. Step S53: Determine whether the second voltage is greater than the second alarm upper limit value or less than the second alarm lower limit value. If so, the calibration fails and the calibration stops; if not, proceed to step S54. Step S54: Pop up a window to prompt whether to continue calibration, and determine whether a continue calibration instruction is received. If so, proceed to step S60; if not, stop the calibration.

7. A method for calibrating a measurement device loop as claimed in claim 1, wherein: The specific steps of step S60 include: Step S61: Create a linear regression formula: y = ax + b; Replace x in the linear regression formula with the two second voltages respectively, and replace y in the linear regression formula with the calibration values corresponding to the second voltages, and then calculate the values of a and b; both a and b represent voltage relationship coefficients. Step S62: Obtain the current ambient temperature, and match the voltage compensation value co from the voltage compensation table according to the ambient temperature and the second voltage, and then obtain the voltage compensation formula for each test gear: y = ax + b + co; Step S63: Obtain the MAC address of the test device to be calibrated, calculate the second MD5 value by using the MD5 algorithm for the MAC address and the voltage compensation formula, package the MAC address, the voltage compensation formula and the second MD5 value into a calibration file in JSON format and store it, and use the calibration file to calibrate the measurement device loop.

8. A method for calibrating a measurement device loop as claimed in claim 1, wherein: It further includes: Step S70: Use the 6Sigma algorithm to analyze each second voltage, and then update the alarm limit value.

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