Method and system for detecting air tightness of plastic pipe connecting piece

Abstract

The invention relates to the technical field of air tightness detection, in particular to an air tightness detection method and system for a plastic pipe connecting piece, and the method comprises the steps: obtaining real-time pressure data and associated temperature data of the interior of a detected plastic connecting piece in an inflation and pressure maintaining process; inputting the real-time pressure data into a temperature and pressure coupling model for pressure value compensation correction to obtain a compensated pressure value only reflecting the leakage effect; performing time sequence change analysis on the compensated pressure value, and identifying and determining a starting time point when the pressure enters a stable state; extracting the dynamic attenuation characteristic of the compensated pressure value; and performing matching degree calculation on the dynamic attenuation characteristics and the reference model of the leakage-free basis behavior to generate an air tightness detection result of the plastic pipe connecting piece. According to the invention, the problem of interference of non-leakage factors such as environment temperature in air tightness detection is effectively solved, the inhibition capability of interference of non-leakage factors such as temperature is enhanced, and the accuracy and reliability of a detection result are improved.

Description

Technical Field

[0001] This invention relates to the field of airtightness testing technology, and in particular to a method and system for testing the airtightness of plastic pipe connectors. Background Technology

[0002] With the widespread application of plastic pipes in building water supply and drainage, gas transmission, home appliances and automotive pipelines, plastic pipe fittings are key components whose airtightness is directly related to the safety and reliability of the pipeline system. Insufficient airtightness often leads to liquid or gas leakage, which in turn causes energy waste, safety accidents or product performance degradation. Therefore, it is of great significance to conduct high-precision airtightness testing on plastic pipe fittings.

[0003] Existing airtightness testing methods are mainly based on the principle of pressure decay, which involves filling the test component with gas and observing the pressure change over a certain period of time to determine whether a leak exists. However, in actual testing, pressure changes are not only caused by leakage effects but are also significantly affected by non-leakage factors such as ambient temperature fluctuations. Since existing methods cannot effectively distinguish between such interferences and actual leakage effects, they often lead to misjudgments or omissions in the test results, thereby reducing the accuracy and reliability of the test. Summary of the Invention

[0004] This invention provides a method and system for testing the airtightness of plastic pipe connectors, thereby effectively solving the problems pointed out in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for testing the airtightness of plastic pipe fittings, comprising: Acquire real-time pressure data and associated temperature data inside the tested plastic connector during the inflation and pressure holding process; The real-time pressure data is input into the temperature-pressure coupling model for pressure value compensation and correction to obtain a compensated pressure value that only reflects the leakage effect. A time series change analysis was performed on the compensated pressure value to identify and determine the starting point when the pressure entered a stable state. During the duration of the stable state, the dynamic attenuation characteristics of the compensated pressure value are extracted. The matching degree between the dynamic attenuation characteristics and the benchmark model of leakage-free behavior is calculated, and the airtightness test results of the plastic pipe connector are generated based on the calculation results.

[0006] Furthermore, the temperature-pressure coupling model includes: the coefficient of linear expansion of the plastic pipe connector material and the state equation parameters of the test gas.

[0007] Furthermore, the real-time pressure data is input into a temperature-pressure coupling model for pressure value compensation and correction to obtain a compensated pressure value that only reflects the leakage effect, including: Calculate the first pressure disturbance caused by the change in pipe volume based on the real-time temperature change and the linear expansion coefficient; Based on the real-time temperature value and the parameters of the state equation of the test gas, the second pressure disturbance caused by the change in the motion of gas molecules is calculated. The first pressure disturbance amount and the second pressure disturbance amount are combined to obtain the comprehensive pressure correction amount; The real-time pressure data is corrected based on the comprehensive pressure correction amount to obtain the compensated pressure value. Furthermore, the first pressure disturbance quantity and the second pressure disturbance quantity are fused to obtain a comprehensive pressure correction quantity, including: Determine the influence of temperature rise or fall on the direction of pressure change, and establish the symbolic physical rules for pressure disturbance quantities; Based on the symbolic physics rules, the first pressure interference quantity and the second pressure interference quantity are algebraically summed to obtain the comprehensive pressure correction quantity.

[0008] Furthermore, a time-series analysis is performed on the compensated pressure value to identify and determine the starting time point when the pressure reaches a stable state, including: The pressure value after compensation is subjected to sliding window differential calculation to obtain the pressure change rate at adjacent time points; Calculate the absolute value of the pressure change rate and compare it with a preset stability threshold; When the absolute value of the pressure change rate is less than the stability threshold for a continuous preset time period, this moment is determined to be the starting point when the pressure enters a stable state.

[0009] Furthermore, during the duration of the stable state, the dynamic attenuation characteristics of the compensated pressure value are extracted, including: Obtain the time sequence data of the compensated pressure value during the duration of the steady state; The sequence data is fitted with a function to obtain characteristic parameters that characterize the pressure decay trend over time. The characteristic parameters include at least a decay rate parameter and a fitting residual parameter. Additional parameters reflecting the stability of the decay process are extracted from the sequence data, and the characteristic parameters and additional parameters are combined to form the dynamic decay characteristics.

[0010] Furthermore, the degree of matching between the dynamic decay characteristics and the baseline model of leakage-free base behavior is calculated, including: The dynamic decay characteristics are compared with the corresponding feature parameters of the benchmark model to obtain the feature difference value; A similarity index is calculated based on the feature difference value. When the similarity index meets the preset matching judgment condition, it is determined to be consistent with the benchmark model; otherwise, it is determined to be inconsistent with the benchmark model.

[0011] Furthermore, before conducting the airtightness test, the following steps are taken: collecting background pressure and temperature data and establishing a baseline curve without the tested component being connected.

[0012] An airtightness testing system for plastic pipe fittings, the system comprising: The real-time data acquisition module acquires real-time pressure data and associated temperature data inside the tested plastic connector during the inflation and pressure holding process. The pressure compensation and correction module inputs the real-time pressure data into the temperature-pressure coupling model to perform pressure value compensation and correction, and obtains a compensated pressure value that only reflects the leakage effect. The steady state determination module performs time series change analysis on the compensated pressure value to identify and determine the starting time point when the pressure enters a steady state. The attenuation characteristic extraction module extracts the dynamic attenuation characteristics of the compensated pressure value during the duration of the stable state. The test result generation module calculates the matching degree between the dynamic attenuation characteristics and the benchmark model of leak-free behavior, and generates the airtightness test result of the plastic pipe connector based on the calculation result.

[0013] Furthermore, the attenuation characteristic extraction module includes: The sequence data acquisition unit acquires the sequence data of the compensated pressure value over time during the duration of the steady state. The feature parameter acquisition unit performs function fitting on the sequence data to obtain feature parameters characterizing the pressure decay trend over time. The feature parameters include at least a decay rate parameter and a fitting residual parameter. The feature parameter combination unit extracts additional parameters reflecting the stability of the decay process from the sequence data, and combines the feature parameters and additional parameters to form the dynamic decay characteristics.

[0014] The technical solution of this invention can achieve the following technical effects: It effectively solves the problem of interference from non-leakage factors such as ambient temperature in airtightness testing, strengthens the ability to suppress interference from non-leakage factors such as temperature, and improves the accuracy and reliability of test results. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating a method for testing the airtightness of plastic pipe fittings. Figure 2 A flowchart illustrating the process to obtain the compensated pressure value that only reflects the leakage effect; Figure 3 A flowchart illustrating the process for obtaining the overall pressure correction amount; Figure 4 A flowchart illustrating the process for identifying and determining the starting point of pressure reaching a steady state; Figure 5 A flowchart illustrating the process of extracting the dynamic attenuation characteristics of the compensated pressure value. Figure 6 A schematic diagram illustrating the process of calculating the matching degree between dynamic decay characteristics and a benchmark model of leakage-free base behavior. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] Example 1 like Figure 1 As shown, the present invention provides a method for testing the airtightness of plastic pipe connectors, the method comprising: S1: Acquire real-time pressure data and associated temperature data inside the tested plastic connector during the inflation and pressure holding process; Specifically, the first step is to collect data from the plastic pipe connector being tested. This involves simultaneously acquiring real-time internal pressure data and corresponding temperature data while inflating and maintaining pressure. To ensure the accuracy of the data acquisition, the testing device is preferably equipped with high-sensitivity pressure and temperature sensors. In terms of data acquisition methods, a higher sampling frequency is preferred, such as more than 100 simultaneous samples per second, to ensure the correspondence between the two types of data in the time dimension. To reduce interference from external factors, an isolation cover can be added to the outside of the testing device. At the same time, filtering algorithms, such as moving average or median filtering, are added to the data acquisition program to suppress occasional noise.

[0020] S2: Input the real-time pressure data into the temperature-pressure coupling model to perform pressure value compensation and correction, and obtain the compensated pressure value that only reflects the leakage effect; Specifically, real-time pressure data is coupled with corresponding temperature data for calculation, and compensation and correction are performed through a temperature-pressure coupling model. Non-leakage components are removed from the original data, and the compensated pressure value is more stable and can accurately represent the real leakage effect of the tested plastic pipe connector during the pressure holding process.

[0021] S3: Perform time series analysis on the compensated pressure value to identify and determine the starting point when the pressure enters a stable state; Specifically, the compensated pressure values ​​are continuously compared in chronological order to observe the changes between adjacent data points. When the changes are all less than the preset threshold for a continuous period of time, the starting point of that period of time is determined to be the beginning of a stable state. In this way, the drastic fluctuations caused by rapid pressure increase in the early stage of inflation can be effectively eliminated, while ensuring that the subsequently extracted attenuation characteristics come from a stable and reliable stage.

[0022] S4: During the duration of the steady state, extract the dynamic attenuation characteristics of the compensated pressure value; Specifically, the compensated pressure values ​​are recorded in chronological order during the stable phase, and their overall trend over time is identified to obtain dynamic characteristics that reflect the gradual decrease in pressure over time. In this way, it is possible to detect whether there is a continuous decrease in pressure during the stable phase, and use this as the basis for subsequent judgment of leakage effects.

[0023] S5: Calculate the matching degree between the dynamic attenuation characteristics and the benchmark model of the leak-free behavior, and generate the airtightness test results of the plastic pipe connector based on the calculation results.

[0024] Specifically, the pressure change pattern under leak-free conditions is obtained through multiple tests in advance, and a corresponding benchmark model is established as a reference for subsequent matching. During the detection process, the extracted dynamic attenuation characteristics are matched with the features of the benchmark model. The detection result is determined based on the degree of matching. If the dynamic attenuation characteristics are highly consistent with the benchmark model, it indicates that there is no leakage in the connector and the detection result is qualified. If the dynamic attenuation characteristics are significantly different from the benchmark model, it indicates that there is leakage and the detection result is unqualified. Preferably, a threshold range can be set during the matching process to distinguish between obviously qualified and obviously unqualified cases, thereby improving the reliability of the judgment.

[0025] This invention effectively solves the problem of interference from non-leakage factors such as ambient temperature in airtightness testing, strengthens the ability to suppress interference from non-leakage factors such as temperature, and improves the accuracy and reliability of test results.

[0026] As a preferred embodiment of the above, the temperature-pressure coupling model includes: the coefficient of linear expansion of the plastic pipe connector material and the state equation parameters of the test gas.

[0027] Specifically, on the one hand, plastic pipe fittings generally exhibit significant thermal expansion and contraction during use. Temperature changes cause slight alterations in their internal volume, which directly affect the actual pressure of the gas being measured. Therefore, introducing the material's linear expansion coefficient can convert structural dimensional changes into quantifiable pressure corrections. On the other hand, the average molecular kinetic energy and pressure state of the gas also change with temperature variations. Based on the parameters of the gas law, the pressure shift caused by these changes can be accurately calculated, thereby eliminating spurious effects unrelated to leakage. Preferably, in specific testing, the material's linear expansion coefficient can be obtained by consulting material data sheets or through experimental calibration, while the gas law parameters can be determined based on the type of gas used in the test.

[0028] As a preferred embodiment of the above, such as Figure 2 As shown, in step S2, the real-time pressure data is input into the temperature-pressure coupling model for pressure value compensation and correction to obtain a compensated pressure value that only reflects the leakage effect, including: S21: Calculate the first pressure disturbance caused by the change in pipe volume based on the real-time temperature change and the coefficient of linear expansion; S22: Calculate the second pressure disturbance caused by changes in gas molecule motion based on real-time temperature values ​​and state equation parameters of the test gas; S23: Combine the first pressure disturbance amount and the second pressure disturbance amount to obtain the comprehensive pressure correction amount; S24: Correct the real-time pressure data based on the comprehensive pressure correction amount to obtain the compensated pressure value.

[0029] Specifically, when the ambient temperature changes, the volume of the plastic pipe fitting also changes. To quantify this effect, the linear expansion coefficient of the fitting material is first determined. Then, combined with the monitored temperature change, the percentage change in volume of the fitting under that temperature condition is obtained. Subsequently, based on the inverse relationship between volume and pressure of a gas under a fixed state, the percentage change in volume is converted into an equivalent pressure change, which is the first pressure interference quantity. At the same time, the change in the molecular motion state of the gas itself needs to be considered. In this process, the influence of temperature increase or decrease on the average kinetic energy of gas molecules is converted into a corresponding pressure change amplitude using real-time temperature values ​​and gas state equation parameters. This change is the second pressure interference quantity. After obtaining the two types of interference quantities, they are merged to form a comprehensive pressure correction quantity, which is more in line with the actual situation under different materials and gas conditions. Finally, the comprehensive pressure correction quantity is applied to the original real-time pressure data to correct the data, thereby eliminating spurious fluctuations introduced by temperature changes. The resulting compensated pressure value can more accurately reflect the real leakage effect.

[0030] As a preferred embodiment of the above, such as Figure 3 As shown, step S23 involves fusing the first pressure disturbance and the second pressure disturbance to obtain a comprehensive pressure correction, including: S231: Determine the influence of temperature rise or fall on the direction of pressure change, and establish the symbolic physical rules for pressure disturbance quantities; S232: Based on the symbolic physics rules, perform algebraic summation on the first and second pressure disturbance quantities to obtain the comprehensive pressure correction quantity.

[0031] Specifically, when the ambient temperature rises, the plastic pipe connector expands due to thermal expansion, increasing its internal volume and thus decreasing the gas pressure. This change is recorded as a negative value in the calculation. Under the same conditions, increased gas molecule motion leads to increased pressure, which is recorded as a positive value. Conversely, when the temperature drops, the material contracts, reducing the volume and increasing the gas pressure, which should be assigned a positive sign. The decreased gas molecule motion leads to decreased pressure, which should be assigned a negative sign. This ensures that both types of disturbances are represented by a unified sign rule under varying temperature conditions, avoiding calculation errors due to opposite directions. After establishing the physical rules for the signs, the first and second pressure disturbances are algebraically summed based on these rules, directly adding their values ​​and signs to obtain the comprehensive pressure correction.

[0032] As a preferred embodiment of the above, such as Figure 4 As shown, step S3 involves performing a time series analysis on the compensated pressure value to identify and determine the starting time point when the pressure reaches a stable state, including: S31: Perform sliding window difference calculation on the compensated pressure value to obtain the pressure change rate at adjacent time points; S32: Calculate the absolute value of the rate of pressure change and compare it with a preset stability threshold; S33: When the absolute value of the pressure change rate is less than the stability threshold within a continuous preset time period, the moment is determined to be the starting point when the pressure enters a stable state.

[0033] Specifically, a sliding window differencing operation is first used to obtain the rate of pressure change between adjacent time points. In this process, the window length and step interval are first set. The window length limits the number of consecutive samples participating in the calculation at one time, while the step interval controls the sliding granularity of the window on the time axis. When the sampling time interval is fixed, the window length is preferably set to cover tens to hundreds of adjacent samples to balance sensitivity and noise resistance, and the step interval is preferably one sample point to achieve point-by-point updates. During the operation, the first window is extracted from the beginning of the sequence, and the difference between the sample at the end of the window and the sample immediately preceding the previous time point is calculated. This difference is then converted into the change per unit time using the time difference corresponding to the sample interval. Subsequently, the window slides forward by one step interval, discarding the earliest sample and including the new sample, repeating the above differencing and conversion process to obtain a rate of change sequence aligned with the original sequence time. To improve the robustness of the results, the original samples can be denoised within the window, for example, by replacing obviously abnormal isolated points with the median, or by performing a smoothing operation before performing the differencing. After obtaining the rate sequence, a light secondary smoothing can be performed to suppress high-frequency jitter. When there are insufficient samples at the boundary, the computational gap can be avoided by shortening the window or mirroring the expansion, and the time stamps can be aligned to the end or center of the window to ensure consistency with the time of subsequent threshold determination. After obtaining the rate sequence, the absolute value of each rate value is taken and compared with a preset stability threshold. When it is detected that the absolute value of the rate is less than the stability threshold for a continuous preset duration, the starting point of that duration can be determined as the moment when the pressure enters a stable state.

[0034] As a preferred embodiment of the above, such as Figure 5 As shown, step S4 involves extracting the dynamic attenuation characteristics of the compensated pressure value during the duration of the steady state, including: S41: Obtain the time-series data of the compensated pressure value during the duration of the steady state; S42: Perform function fitting on the sequence data to obtain characteristic parameters that characterize the pressure decay trend over time. The characteristic parameters include at least the decay rate parameter and the fitting residual parameter. S43: Extract additional parameters reflecting the stability of the decay process from the sequence data, and combine the characteristic parameters and additional parameters to form dynamic decay characteristics.

[0035] Specifically, the compensated pressure value sequence data for the specified time period is acquired. This data is recorded in its entirety according to the sampling time sequence, forming a continuous time series for analysis. Next, the sequence data is fitted with a function to reveal the overall trend of pressure decay over time. A preferred approach is to fit the data segment with a linear or exponential function, and extract characteristic parameters that quantify the decay process from the fitting results. These parameters include at least a decay rate parameter representing the rate of decrease, and a residual parameter reflecting the difference between the fitted curve and the actual data. These two types of parameters respectively characterize the strength and regularity of the decay effect. Additional parameters reflecting the stability of the decay process can also be extracted from the original sequence data itself, such as calculating the variance, root mean square, or range of the sequence during the specified time period to measure data fluctuations. Finally, the decay rate parameter, the fitting residual parameter, and the aforementioned additional parameters are combined to form a complete dynamic decay characteristic, which is used for subsequent matching calculations with a leak-free benchmark model.

[0036] As a preferred embodiment of the above, such as Figure 6 As shown, the degree of matching between the dynamic decay characteristics and the baseline model of leakage-free base behavior is calculated, including: A10: Compare the dynamic decay characteristics with the corresponding characteristic parameters of the benchmark model to obtain the characteristic difference value; A20: Calculate the similarity index based on the feature difference value. When the similarity index meets the preset matching judgment conditions, it is judged to be consistent with the benchmark model; otherwise, it is judged to be inconsistent with the benchmark model.

[0037] Specifically, the decay rate, fitting residual, and volatility parameters included in the dynamic decay characteristics are compared one by one with the corresponding feature parameters in the benchmark model to obtain the difference values ​​between each parameter. These difference values ​​can reflect the degree of deviation between the behavior of the tested component in the actual testing process and the leak-free behavior. Then, based on the difference values, the overall similarity index is calculated. The preferred method is to use methods such as correlation coefficient, relative error ratio, or distance measurement to integrate the differences of each feature into a similarity score. When the score meets the preset judgment conditions, the dynamic decay characteristics are considered to be consistent with the benchmark model, and the plastic pipe connector is judged to be a qualified part. Otherwise, it is judged to be a non-qualified part. In order to avoid misjudgment caused by a single parameter, it is preferable to set a combination of multiple judgment conditions. For example, it is required that the decay rate difference is lower than a certain range and the fitting residual is close to zero before it is judged to be consistent.

[0038] As a preferred embodiment of the above, before performing the airtightness test, the method includes: collecting background pressure and temperature data and establishing a baseline curve without the tested component being connected.

[0039] Specifically, without the device under test connected, the detection device maintains the same working environment and gas source conditions as subsequent tests, continuously collecting pressure and temperature data for a period of time. This data does not reflect leakage behavior, but rather the system's inherent background state. By processing the collected background data, a baseline curve can be established to characterize the inherent fluctuation characteristics of the detection environment and device under leak-free conditions. This step is necessary because in actual testing, gas source pressure may fluctuate slowly, sensors may experience zero-point drift over time, and periodic changes in ambient temperature can also cause superimposed interference to the pressure data. Without correction, a false attenuation trend resembling a leak may appear even when there is no leak, leading to misjudgment. The preferred approach is to statistically average or trend-fit the background data to obtain a smooth and stable baseline. In subsequent tests, when real-time pressure and temperature data are collected, they can be compared or corrected against this baseline to eliminate systematic interference caused by gas source fluctuations, sensor zero-point drift, or changes in ambient temperature.

[0040] Example 2 Based on the same inventive concept as the airtightness testing method for a plastic pipe connector in the foregoing embodiments, the present invention also provides an airtightness testing system for a plastic pipe connector, the system comprising: The real-time data acquisition module acquires real-time pressure data and associated temperature data inside the tested plastic connector during the inflation and pressure holding process. The pressure compensation and correction module inputs real-time pressure data into the temperature-pressure coupling model to compensate and correct the pressure value, resulting in a compensated pressure value that only reflects the leakage effect. The steady state determination module performs time series change analysis on the compensated pressure value to identify and determine the starting time point when the pressure enters a steady state. The attenuation characteristic extraction module extracts the dynamic attenuation characteristics of the compensated pressure value during the duration of the steady state. The test result generation module calculates the matching degree between the dynamic attenuation characteristics and the benchmark model of the leak-free behavior, and generates the airtightness test results of the plastic pipe connector based on the calculation results.

[0041] The detection system described above in this invention can effectively realize the airtightness detection method for plastic pipe connectors, and the technical effects it can achieve are as described in the above embodiments, and will not be repeated here.

[0042] As a preferred embodiment of the above, the attenuation characteristic extraction module includes: The sequence data acquisition unit acquires the sequence data of the compensated pressure value over time during the duration of the steady state. The feature parameter acquisition unit performs function fitting on the sequence data to obtain feature parameters that characterize the pressure decay trend over time. The feature parameters include at least the decay rate parameter and the fitting residual parameter. The feature parameter combination unit extracts additional parameters reflecting the stability of the decay process from the sequence data, and combines the feature parameters and additional parameters to form dynamic decay characteristics.

[0043] Similarly, the above-mentioned optimization schemes for the system can also achieve the optimization effects corresponding to the methods in Embodiment 1, which will not be repeated here.

[0044] Although this application has been described in conjunction with specific features and embodiments, it will be apparent that various modifications and combinations can be made therein without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of this application and its equivalents, this application intends to include such modifications and variations.

Claims

1. A method for testing the airtightness of plastic pipe connectors, characterized in that, include: Acquire real-time pressure data and associated temperature data inside the tested plastic connector during the inflation and pressure holding process; The real-time pressure data is input into the temperature-pressure coupling model for pressure value compensation and correction to obtain a compensated pressure value that only reflects the leakage effect. A time series change analysis was performed on the compensated pressure value to identify and determine the starting point when the pressure entered a stable state. During the duration of the stable state, the dynamic attenuation characteristics of the compensated pressure value are extracted. The matching degree between the dynamic attenuation characteristics and the benchmark model of leakage-free behavior is calculated, and the airtightness test results of the plastic pipe connector are generated based on the calculation results.

2. The method for testing the airtightness of plastic pipe connectors according to claim 1, characterized in that, The temperature-pressure coupling model includes the linear expansion coefficient of the plastic pipe connector material and the state equation parameters of the test gas.

3. The method for testing the airtightness of plastic pipe connectors according to claim 2, characterized in that, The real-time pressure data is input into a temperature-pressure coupling model for pressure value compensation and correction to obtain a compensated pressure value that only reflects the leakage effect, including: Calculate the first pressure disturbance caused by the change in pipe volume based on the real-time temperature change and the linear expansion coefficient. Based on the real-time temperature value and the parameters of the state equation of the test gas, the second pressure disturbance caused by the change in the motion of gas molecules is calculated. The first pressure disturbance amount and the second pressure disturbance amount are combined to obtain the comprehensive pressure correction amount; The real-time pressure data is corrected based on the comprehensive pressure correction amount to obtain the compensated pressure value.

4. The method for testing the airtightness of plastic pipe connectors according to claim 3, characterized in that, The first pressure disturbance and the second pressure disturbance are fused to obtain a comprehensive pressure correction, including: Determine the influence of temperature rise or fall on the direction of pressure change, and establish a symbolic physical rule for pressure disturbance quantities; Based on the symbolic physics rules, the first pressure interference quantity and the second pressure interference quantity are algebraically summed to obtain the comprehensive pressure correction quantity.

5. The method for testing the airtightness of plastic pipe connectors according to claim 1, characterized in that, A time series analysis was performed on the compensated pressure value to identify and determine the starting point at which the pressure entered a stable state, including: The pressure value after compensation is subjected to sliding window differential calculation to obtain the pressure change rate at adjacent time points; Calculate the absolute value of the pressure change rate and compare it with a preset stability threshold; When the absolute value of the pressure change rate is less than the stability threshold for a continuous preset time period, this moment is determined to be the starting point when the pressure enters a stable state.

6. The method for testing the airtightness of plastic pipe connectors according to claim 1, characterized in that, During the duration of the stable state, the dynamic attenuation characteristics of the compensated pressure value are extracted, including: Obtain the time sequence data of the compensated pressure value during the duration of the steady state; The sequence data is fitted with a function to obtain characteristic parameters that characterize the pressure decay trend over time. The characteristic parameters include at least a decay rate parameter and a fitting residual parameter. Additional parameters reflecting the stability of the decay process are extracted from the sequence data, and the characteristic parameters and additional parameters are combined to form the dynamic decay characteristics.

7. The method for testing the airtightness of plastic pipe connectors according to claim 1, characterized in that, The matching degree between the dynamic decay characteristics and the benchmark model of leakage-free base behavior is calculated, including: The dynamic decay characteristics are compared with the corresponding feature parameters of the benchmark model to obtain the feature difference value; A similarity index is calculated based on the feature difference value. When the similarity index meets the preset matching judgment condition, it is determined to be consistent with the benchmark model; otherwise, it is determined to be inconsistent with the benchmark model.

8. The method for testing the airtightness of plastic pipe connectors according to claim 1, characterized in that, Before conducting airtightness testing, the following steps are taken: collecting background pressure and temperature data and establishing a baseline curve without the tested component connected.

9. A system for detecting the airtightness of plastic pipe connectors, characterized in that, The system includes: The real-time data acquisition module acquires real-time pressure data and associated temperature data inside the tested plastic connector during the inflation and pressure holding process. The pressure compensation and correction module inputs the real-time pressure data into the temperature-pressure coupling model to perform pressure value compensation and correction, and obtains a compensated pressure value that only reflects the leakage effect. The steady state determination module performs time series change analysis on the compensated pressure value to identify and determine the starting time point when the pressure enters a steady state. The attenuation characteristic extraction module extracts the dynamic attenuation characteristics of the compensated pressure value during the duration of the stable state. The test result generation module calculates the matching degree between the dynamic attenuation characteristics and the benchmark model of leak-free behavior, and generates the airtightness test result of the plastic pipe connector based on the calculation result.

10. The airtightness testing system for plastic pipe connectors according to claim 9, characterized in that, The attenuation characteristic extraction module includes: The sequence data acquisition unit acquires the sequence data of the compensated pressure value over time during the duration of the steady state. The feature parameter acquisition unit performs function fitting on the sequence data to obtain feature parameters characterizing the pressure decay trend over time. The feature parameters include at least a decay rate parameter and a fitting residual parameter. The feature parameter combination unit extracts additional parameters reflecting the stability of the decay process from the sequence data, and combines the feature parameters and additional parameters to form the dynamic decay characteristics.

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