Pressure transmitter debugging method

Abstract

The invention relates to the field of pressure transmitters, in particular to a pressure transmitter debugging method, which comprises the following steps of: acquiring characteristic curve data, selecting a plurality of data points as a control group in a full scale, calculating the slope of the control group by using a least square method, and determining an error range. A to-be-debugged pressure transmitter is divided into a plurality of intervals in the full scale, pressure is slowly applied in each interval by using a pressure source, a corresponding output signal value is recorded, and a characteristic curve of each interval is constructed. Comparing the slopes of the debugging group and the control group, and judging abnormity and debugging according to the slope change trend. After error interval debugging is completed, full-scale overall testing is carried out, a newly-built full-scale characteristic curve and a control group curve are compared, and the qualified curve is marked and recorded. According to the method, the abnormal interval can be quickly found through curve fitting and slope comparison; simulation abnormal data is introduced into long-short-term memory network model training, and the abnormal mode recognition capability is enhanced; the abnormal priority is set, the debugging efficiency is improved, and the measurement precision of the pressure transmitter is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of pressure transmitters, and particularly to a method for debugging a pressure transmitter. Background Art

[0002] In the application of pressure transmitters, accurate pressure measurement is crucial for many fields such as industrial production and scientific research. With the continuous improvement of industrial automation, the usage scenarios of pressure transmitters are becoming increasingly complex and diverse. From pipeline pressure monitoring in chemical production to aircraft pressure detection in the aerospace field, higher requirements are put forward for the measurement accuracy and stability of pressure transmitters. Before actual use, debugging the pressure transmitter is a key link to ensure its reliable performance. Traditional methods for debugging pressure transmitters often rely on simple empirical judgments or basic measurement comparisons, lacking systematicness and precision. In the face of complex industrial environments and high-precision measurement requirements, these traditional methods gradually expose many problems.

[0003] Therefore, it is necessary to propose a method for debugging a pressure transmitter to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for debugging a pressure transmitter to solve the problems of relying on simple empirical judgments or basic measurement comparisons and lacking systematicness and precision.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: A method for debugging a pressure transmitter, comprising the following steps: S1. Obtain the characteristic curve data of the test pressure and output signal value of the pressure transmitter that meets the existing standards from the product standard document of the pressure transmitter, and select multiple data points within the full range of the pressure transmitter as the control group; S2. According to the obtained data, use the least squares curve fitting method to calculate the slope of the characteristic curve of the control group, and determine the slope error range according to the standard or experience; S3. Divide the full range of the pressure transmitter to be debugged into multiple pressure range intervals as the debugging group. For each set pressure range interval, slowly apply pressure using a pressure source, and use a standard signal measuring instrument to measure and record the output signal values corresponding to each point within the pressure range interval; S4. For the data collected within each pressure range interval, use the same curve fitting method as the control group to construct the characteristic curve of this interval; S5. Compare the slope of the characteristic curve of each pressure range interval in the debugging group with the slope of the characteristic curve of the control group. For those exceeding the slope error range, make an abnormal judgment and corresponding debugging according to the slope change trend corresponding to the pressure range interval.

[0006] Preferably, after debugging all error pressure range intervals, a comprehensive test of the pressure transmitter to be debugged is carried out over the full range. Multiple pressure points are evenly selected again within the full range, the output signal values are measured according to the above data acquisition method, and a new full-range characteristic curve is constructed.

[0007] Preferably, the newly constructed full-range characteristic curve is comprehensively compared with the control group characteristic curve, including slope, linearity, zero point, and range output data. The pressure transmitters that pass the debugging are marked and recorded. The recorded content includes the characteristic curve data before and after debugging, the measures taken during the debugging process, and the final debugging result information.

[0008] Preferably, before debugging the pressure transmitter to be debugged, ensure that the pressure transmitter is correctly installed in the measurement system and is correctly connected to the power supply and the display instrument or control system. Close the valve between the pressure transmitter and the measured medium to isolate the measurement chamber of the pressure transmitter from the measured pressure and ensure that the pressure in the measurement chamber is zero at this time.

[0009] Preferably, power on the pressure transmitter. After it works stably, use a multimeter to measure the output signal value of the pressure transmitter. Slowly adjust the zero adjustment knob with a screwdriver while observing the output reading of the multimeter until the output signal reaches the standard zero value.

[0010] Preferably, the output signal value of the pressure transmitter is a current signal value.

[0011] Preferably, the characteristic curve has the pressure value as the abscissa and the output signal value as the ordinate, and the characteristic curve of the control group is a straight line.

[0012] Preferably, in step S5, the abnormal judgment is carried out according to the slope change trend, including the following steps: S51: Conduct multiple tests on the slope data exceeding the slope error range within the pressure range interval, and construct a time series of these slope values in chronological order; S52: Use the long short-term memory network model to identify the abnormal patterns in the slope time series by learning the normal slope change pattern of the control group and judge the abnormal type; S53: Cluster the slope time series of different pressure range intervals, cluster the intervals with similar slope change patterns into one category, and judge the specific abnormal reasons by analyzing the common characteristics of the environmental parameters and internal states of each category of intervals.

[0013] Preferably, in step S52, when training the long short-term memory network model, in addition to using the data of the normal slope change pattern of the control group, simulated abnormal slope data of different degrees are also introduced to enhance the model's ability to identify various abnormal patterns.

[0014] Preferably, in step S52, after identifying the abnormal patterns using the long short-term memory network model, different priorities are set for different types of abnormalities. The abnormalities with higher priorities are preferentially debugged, and the priorities are determined according to the degree of influence of the abnormalities on the measurement accuracy of the pressure transmitter.

[0015] Technical effects and advantages of the present invention: 1. By using the same curve fitting method as the control group to construct the characteristic curves of each interval of the debugging group and comparing the slopes of the debugging group and the control group, the effect of quickly detecting the abnormalities of the pressure transmitter is achieved, and the pressure range interval where problems may exist is located in a timely manner, facilitating subsequent targeted debugging.

[0016] 2. By introducing simulated abnormal slope data during the training of the long short-term memory network model, the effect of enhancing the model's recognition ability for various abnormal patterns is achieved, enabling the model to more accurately judge the types of abnormalities and improving the accuracy and reliability of abnormality judgment.

[0017] 3. By setting priorities for different types of abnormalities and debugging the abnormalities according to the priorities, the effect of efficiently solving key problems is achieved. The abnormalities that have a greater impact on the measurement accuracy are preferentially processed, improving the debugging efficiency and ensuring the measurement accuracy of the pressure transmitter. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a pressure transmitter debugging method of the present invention.

[0019] Figure 2 It is a schematic structural diagram for judging the abnormality of the slope change trend of the present invention. Detailed Embodiments

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] The present invention provides a pressure transmitter debugging method as Figure 1-2 shown, including the following steps; S1. Obtain the characteristic curve data of the test pressure and output signal value of the pressure transmitter that meets the existing standards from the product standard document of the pressure transmitter, and select multiple data points within the full range of the pressure transmitter as the control group; S2. According to the obtained data, use the least squares curve fitting method to calculate the slope of the characteristic curve of the control group, and determine the slope error range according to the standard or experience; S3. Divide the full range of the pressure transmitter to be debugged into multiple pressure range intervals as the debugging groups. For each set pressure range interval, slowly apply pressure using a pressure source, and use a standard signal measuring instrument to measure and record the output signal values corresponding to each point within the pressure range interval. Before debugging the pressure transmitter to be debugged, ensure that the pressure transmitter is correctly installed in the measurement system, and is correctly connected to the power supply and the display instrument or control system. Close the valve between the pressure transmitter and the measured medium to isolate the measurement chamber of the pressure transmitter from the measured pressure, and ensure that the pressure in the measurement chamber is zero at this time. Power on the pressure transmitter. After it stabilizes, use a multimeter to measure the output signal value of the pressure transmitter. Slowly adjust the zero adjustment knob with a screwdriver while observing the output reading of the multimeter until the output signal reaches the standard zero value. The output signal value of the pressure transmitter is a current signal value. The characteristic curve uses the pressure value as the abscissa and the output signal value as the ordinate, and the characteristic curve of the control group is a straight line. S4. For the data collected within each pressure range interval, use the same curve fitting method as the control group to construct the characteristic curve of this interval. S5. Compare the slopes of the characteristic curves of each pressure range interval in the debugging group with the slope of the characteristic curve of the control group. For those exceeding the slope error range, make an abnormal judgment and corresponding debugging according to the slope change trend corresponding to the pressure range interval.

[0022] Further, after completing the debugging of all error pressure range intervals, conduct an overall test of the full range of the pressure transmitter to be debugged. Re-uniformly select multiple pressure points within the full range, measure the output signal values according to the above data collection method, and construct a new full-range characteristic curve. Comprehensively compare the newly constructed full-range characteristic curve with the characteristic curve of the control group, including slope, linearity, zero point, and range output data. Mark and record the pressure transmitters that pass the debugging. The recorded content includes the characteristic curve data before and after debugging, the measures taken during the debugging process, and the final debugging result information.

[0023] In an embodiment of the present invention, within the full range of the pressure transmitter, multiple data points are uniformly and reasonably selected. For a pressure transmitter with a range of 0 - 10 MPa, 11 data points such as 0 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, and 10 MPa can be selected as the control group. The selection of data points should be able to fully reflect the relationship between pressure and output signal value, and avoid the data points being too concentrated or sparse. Arrange the data points selected in step S1 in ascending order of pressure values, and record the corresponding output signal values. Use the least squares fitting function in the software to perform curve fitting on the data. When fitting, check whether the data input is correct, exclude the interference of abnormal data points, and try to use different fitting methods or adjust the fitting parameters to improve the fitting accuracy; with the pressure value as the independent variable and the output signal value as the dependent variable, fit a straight line equation , where k is the slope. Determine the error range of the slope according to the accuracy grade standard of the reference product, industry experience, and the requirements of actual applications. For a pressure transmitter with an accuracy of ±0.5%, the slope error range k±0.5% can be obtained according to the fitting; For a range of 0-10 MPa, it can be divided into 5 intervals: 0-2 MPa, 2-4 MPa, 4-6 MPa, 6-8 MPa, and 8-10 MPa. Use a pressure source, such as a manual pressure pump or an electric pressure controller, to slowly apply pressure to the pressure transmitter. Starting from the lower limit of each pressure range interval, increase the pressure increment by 0.1 MPa step by step to the upper limit. After each pressure stabilizes, wait for 1-2 minutes to ensure that the output signal of the pressure transmitter is stable. Use a standard signal measuring instrument, a high-precision multimeter, to measure and record the output signal value corresponding to this pressure point; Use the least squares method to perform curve fitting on the data within each pressure range interval to obtain the characteristic curve equation of this interval , where is the slope of this interval, and i represents the i-th pressure range interval; Check whether there are errors or abnormal data points in the data acquisition process, and correct or eliminate the abnormal data; try different fitting methods or adjust the fitting parameters to improve the fitting accuracy; Compare the slope of each pressure range interval obtained in step S4 with the control group slope k obtained in step S2 to judge whether it is within the slope error range , where is the error range; If the slope of a certain pressure range interval or multiple consecutive intervals continuously exceeds the error upper limit, it may be that the gain of the amplifier circuit of the pressure transmitter is too high, the sensitivity of the sensor abnormally increases, or there is external interference causing signal enhancement; If the slope of a certain pressure range interval or multiple consecutive intervals continuously is less than the error lower limit, it may be due to too low gain of the amplifier circuit, sensor aging or damage, signal transmission line loss, etc.; If the slope fluctuates greatly within different pressure range intervals and there is no obvious pattern, it may be that the internal circuit of the pressure transmitter is unstable, the sensor is affected by mechanical vibration or electromagnetic interference, etc.; For the cases where the slope is too large or too small, it can be corrected by adjusting the gain of the amplifier circuit inside the pressure transmitter. When the slope is too large, appropriately reduce the gain of the amplifier circuit; when the slope is too small, increase the gain of the amplifier circuit. For the case where the slope fluctuates abnormally, check the environment around the pressure transmitter and eliminate the influence of factors such as mechanical vibration and electromagnetic interference. Measures such as strengthening the installation and shielding electromagnetic interference can be taken.

[0024] In step S5, abnormal judgment is performed according to the slope change trend, including the following steps: S51: Conduct multiple tests on the slope data within the pressure range interval that exceeds the slope error range, and construct a time series of these slope values in chronological order; Use time series analysis methods such as autoregressive integrated moving average model to model the slope time series. By analyzing the historical slope data, predict the future change trend of the slope. Use the ARIMA model to fit and predict the slope time series of a certain pressure range interval to obtain the slope prediction values at several future test moments.

[0025] S52: Use the long short-term memory network model to identify the abnormal patterns in the slope time series by learning the normal slope change patterns of the control group, and judge the abnormal types; S53: Cluster the slope time series of different pressure range intervals, cluster the intervals with similar slope change patterns into one category, and judge the specific abnormal reasons by analyzing the common characteristics of the environmental parameters and internal states of each category of intervals; Furthermore, in step S52, when training the long short-term memory network model, in addition to using the data of the normal slope change patterns of the control group, different degrees of simulated abnormal slope data are introduced to enhance the model's ability to identify various abnormal patterns; Furthermore, in step S52, after identifying the abnormal patterns using the long short-term memory network model, set priorities for different abnormal types respectively. The abnormalities with higher priorities are debugged first, and the priorities are determined according to the degree of influence of the abnormalities on the measurement accuracy of the pressure transmitter.

[0026] In an embodiment of the present invention, for the slope data within the pressure range interval that exceeds the slope error range, use a pressure source and a standard signal measuring instrument, and perform at least 10 - 15 pressure tests on this pressure range interval according to the method of collecting data of the debugging group in step S3. Each time during the test, measure and record the corresponding output signal value after the pressure is stable, and then use the same curve fitting method as in step S4 to calculate the slope value of this test, ensuring that there is a certain time interval between each test to simulate different states in actual work; Arrange the recorded slope values in the order of the test time to form a slope time series. The slope value of the first test is , the second is , and so on, to obtain the sequence , where n is the number of tests; According to the processed data, determine the parameters p (autoregressive term order), d (differencing order), and q (moving average term order) of the model through the autocorrelation function and partial autocorrelation function plots; use the selected model parameters to fit the slope time series; Organize the normal slope change pattern data of the control group obtained in step S1 into a format suitable for input to the long short-term memory network model. According to the possible abnormal conditions of the pressure transmitter, such as sudden increase in slope, sudden decrease, periodic fluctuation, etc., generate simulated abnormal slope data of different degrees; merge the normal slope data and the simulated abnormal slope data, and divide the data set according to a certain ratio to achieve model construction; Input the slope time series constructed in step S51 into the trained model, and the model will output whether each data point is an abnormal pattern and the corresponding abnormal type; set the priority. An abnormal situation where the slope suddenly increases or decreases and the amplitude is large may cause a serious deviation in the measurement result, and it is set as a high priority; while the abnormal situation of small periodic fluctuations in the slope has a relatively small impact on the measurement accuracy and is set as a low priority. A priority table can be formulated to clarify the priority levels corresponding to different abnormal types; For each cluster, collect the environmental parameters corresponding to the interval of this class, such as temperature, humidity, electromagnetic interference intensity, and the internal state parameters of the pressure transmitter, such as chip temperature, power supply voltage stability, etc., analyze the common characteristics of these parameters, and find out the possible reasons for the slope abnormality of this class.

[0027] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A pressure transmitter debugging method, characterized in that: The following steps are involved: S1. Obtain the characteristic curve data of the test pressure and output signal value of the pressure transmitter that meets the existing standards from the product standard document of the pressure transmitter, and select multiple data points within the full range of the pressure transmitter as the control group; S2. Calculate the slope of the control group characteristic curve using the least squares curve fitting method based on the acquired data, and determine the slope error range based on standards or experience; S3. Divide the full range of the pressure transmitter to be debugged into multiple pressure range intervals as debugging groups. For each set pressure range interval, use a pressure source to slowly apply pressure, and use a standard signal measuring instrument to measure and record the output signal value corresponding to each point in the pressure range interval; S4. For the data collected within each pressure range, the characteristic curve of the range is constructed using the same curve fitting method as the control group; S5. Compare the slope of the characteristic curve of each pressure range interval of the debugging group with the slope of the characteristic curve of the control group. For those that exceed the slope error range, make abnormal judgment and corresponding debugging according to the slope change trend corresponding to the pressure range interval.

2. A pressure transmitter debugging method according to claim 1, characterized in that: The method also includes: after completing the debugging of all error pressure range intervals, performing an overall test of the full range of the pressure transmitter to be debugged, re-selecting multiple pressure points evenly within the full range, measuring the output signal value according to the above data acquisition method, and constructing a new full-range characteristic curve.

3. A pressure transmitter debugging method according to claim 2, characterized in that: The newly constructed full-scale characteristic curve is comprehensively compared with the characteristic curve of the control group, including the slope, linearity, zero point and range output data. The pressure transmitters that have passed the debugging are marked and recorded. The records include the characteristic curve data before and after debugging, the measures taken during the debugging process, and the final debugging result information.

4. A pressure transmitter debugging method according to claim 1, characterized in that: Before debugging the pressure transmitter to be debugged, ensure that the pressure transmitter has been correctly installed in the measurement system and is correctly connected to the power supply and display instrument or control system. Close the valve between the pressure transmitter and the measured medium to isolate the measuring cavity of the pressure transmitter from the measured pressure and ensure that the pressure in the measuring cavity is zero at this time.

5. A pressure transmitter debugging method according to claim 4, characterized in that: Power on the pressure transmitter, and use a multimeter to measure the output signal value of the pressure transmitter after it works stably. Slowly adjust the zero adjustment knob with a screwdriver and observe the output reading of the multimeter at the same time until the output signal reaches the standard zero value.

6. A pressure transmitter debugging method according to claim 1, characterized in that: The output signal value of the pressure transmitter is a current signal value.

7. A pressure transmitter debugging method according to claim 1, characterized in that: The characteristic curve has the pressure value as the horizontal coordinate and the output signal value as the vertical coordinate, and the characteristic curve of the control group is a straight line.

8. A pressure transmitter debugging method according to claim 1, characterized in that: In step S5, abnormality judgment is performed according to the slope change trend, including the following steps: S51: performing multiple tests on the slope data exceeding the slope error range within the pressure range, and constructing a time series with these slope values ​​in chronological order; S52: Using the long short-term memory network model, the abnormal pattern in the slope time series is identified by learning the normal slope change pattern of the control group, and the abnormal type is determined; S53: Cluster the slope time series of intervals in different pressure ranges, group the intervals with similar slope change patterns into one category, and determine the specific abnormal cause by analyzing the common characteristics of the environmental parameters and internal states of each category of intervals.

9. A pressure transmitter debugging method according to claim 8, characterized in that: In step S52, when training the long short-term memory network model, in addition to using the normal slope change pattern data of the control group, simulated abnormal slope data of different degrees are also introduced to enhance the model's ability to recognize various abnormal patterns.

10. A pressure transmitter debugging method according to claim 8, characterized in that: In step S52, after the abnormal pattern is identified using the long short-term memory network model, priorities are set for different abnormal types, and abnormalities with high priorities are debugged first. The priority is determined according to the degree of influence of the abnormality on the measurement accuracy of the pressure transmitter.

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