Calibration device of automobile emission analysis system

Abstract

The invention relates to a calibration device of an automobile emission analysis system, and belongs to the technical field of automobile exhaust emission detection.The calibration device comprises a flexible air bag, a multi-channel gas divider, a gas circuit control module and a controller, a gas outlet of the multi-channel gas divider is connected with a gas inlet of the flexible air bag, and a gas outlet of the multi-channel gas divider is connected with a gas outlet of the flexible air bag; an air outlet of the flexible air bag is connected with the air path control module through a pipeline, and the flexible air bag is also connected with a sampling port of the discharge analyzer to be calibrated through a pipeline; zero gas and distance gas are mixed through a multi-channel gas divider to generate calibration gas with known concentration, the calibration gas is stored in a flexible gas bag, the pressure of the gas bag is adjusted through a gas path control module to simulate an actual sampling environment, and accurate calibration of the emission analyzer to be calibrated is completed in combination with temperature compensation and a nonlinear correction algorithm. According to the invention, efficient and accurate calibration of the automobile emission analysis system is realized, the calibration efficiency and accuracy are improved, the measurement error is effectively reduced, and emission test requirements under various working conditions are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile exhaust emission detection, and in particular to a calibration device of an automobile emission analysis system. BACKGROUND

[0002] With the increasing severity of global environmental problems, automobile exhaust emissions, as one of the main sources of urban air pollution, have received widespread attention. Governments around the world have developed strict automobile emission standards, requiring automobile manufacturers and testing agencies to accurately detect and control automobile exhaust emissions. The automobile emission analysis system, as a key device for detecting the composition of automobile exhaust, its accuracy is directly related to the reliability of the emission detection results, and then affects whether the automobile can meet the environmental protection standards.

[0003] However, the existing automobile emission analysis system has some problems in actual application, which leads to the calibration process is not accurate and reliable. First, the self-calibration gas path of the device itself is inconsistent with the sampling gas path, the self-calibration gas path usually uses the pressure of the gas cylinder to provide the flow, while the sampling gas path uses the gas pump to provide the flow. This difference leads to sampling from the normal pressure gas flow, which makes the analysis result deviate. Secondly, the existing device lacks effective external calibration means, which cannot ensure the accuracy of the analysis system. In addition, the calibration method in the prior art is complex to operate, time-consuming, and cannot monitor and adjust the parameters in the calibration process in real time, resulting in low calibration efficiency. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a calibration device of an automobile emission analysis system, which aims to solve at least one of the above technical problems.

[0005] The technical solution of the present application to solve the above technical problems is as follows: The present application provides a calibration device of an automobile emission analysis system, which adopts the following technical solution: A calibration device of an automobile emission analysis system, comprising a flexible gas bag, a multi-channel gas divider, a gas path control module and a controller, the gas path control module is electrically connected with the controller, the gas outlet of the multi-channel gas divider is connected with the gas inlet of the flexible gas bag, the gas outlet of the flexible gas bag is connected with the gas path control module through a pipeline, and the flexible gas bag is also connected with the sampling port of the calibrated emission analyzer through a pipeline; The multi-channel gas divider is used for mixing zero gas and distance gas based on preset target concentration information to obtain calibration gas with known concentration, and conveying the calibration gas to the flexible gas bag; The flexible gas bag is used for storing the calibration gas and simulating a pressureless sampling environment; The controller is used for selecting a gas path mode based on a set calibration control process; The gas path control module is configured to adjust the pressure of the flexible gas bag based on a selected gas path mode, wherein the gas path mode is any one of a filling mode, an emptying mode, a purging mode, a gas distribution mode and a calibration mode, wherein the filling mode represents a mode of filling the flexible gas bag with external gas, the emptying mode represents a mode of pumping the gas in the flexible gas bag to the external environment, the purging mode represents a mode of circulating zero gas to flush each pipeline and the flexible gas bag, the gas distribution mode represents a mode of driving mixed gas to be delivered to the flexible gas bag, and the calibration mode represents a mode of sampling the calibration gas in the flexible gas bag. The controller is further configured to acquire, in real time, concentration information of the calibration gas in the flexible gas bag when the pressure in the flexible gas bag reaches a set target pressure threshold, control the to-be-calibrated emission analyzer to sample the calibration gas based on the concentration information of the calibration gas, and acquire concentration information output by the to-be-calibrated emission analyzer, and generate a calibration curve based on the concentration information output by the to-be-calibrated emission analyzer, target concentration information, a set temperature compensation algorithm and a nonlinear correction algorithm.

[0006] The calibration device of the application can simulate a real pressureless sampling environment by using the flexible gas bag, effectively solve the problem of pressure difference between the calibration gas path and the sampling gas path, and thus improve the accuracy of calibration. The multi-channel gas divider can accurately mix zero gas and calibration gas to generate calibration gas, ensuring the controllability and consistency of the concentration of the calibration gas. The gas path control module supports filling, emptying and purging modes, which not only realizes flexible regulation and control of the pressure in the flexible gas bag, but also effectively cleans the pipeline and reduces the influence of residual gas on the next calibration. The controller intelligently manages the entire calibration process, including real-time monitoring of the gas concentration in the flexible gas bag, adjusting the working state of the gas pump according to the preset algorithm, and generating a calibration curve by comprehensively considering various factors, which greatly improves the efficiency and reliability of the calibration work.

[0007] On the basis of the above technical solution, the application can also be improved as follows.

[0008] Further, the material of the flexible gas bag is a double-layer fluorinated ethylene propylene copolymer film.

[0009] The beneficial effect of the above further scheme is that the flexible gas bag selects a double-layer fluorinated ethylene propylene copolymer film as the material, which improves the corrosion resistance and durability of the gas bag, effectively blocks gas permeation, and ensures the reliability of long-term use.

[0010] Further, the flexible gas bag is provided with an X-shaped guide pipe, an input end of the X-shaped guide pipe is communicated with the multi-channel gas divider, and gas outlets are uniformly arranged on the X-shaped guide pipe, and the X-shaped guide pipe is connected with an outlet gas pipe of the flexible gas bag.

[0011] The beneficial effect of the further scheme is that the design of the X-shaped guide pipe enables the mixed gas to be uniformly distributed in the gas bag, reduces the concentration gradient, and improves the calibration accuracy.

[0012] Further, the inner wall of the X-shaped guide pipe is coated with a nano ceramic coating.

[0013] The beneficial effect of the further scheme is that the nano ceramic coating on the inner wall reduces the gas adsorption rate and reduces the influence on the calibration gas concentration.

[0014] Further, the flexible gas bag is provided with a pressure sensor, the pressure sensor is connected with the controller, and the pressure sensor is used to detect the pressure in the flexible gas bag.

[0015] The beneficial effect of the further scheme is that the pressure sensor monitors the internal pressure of the gas bag in real time, and the controller realizes accurate pressure control, ensures that the pressure in the gas bag is maintained within the target range, eliminates the pressure difference between the calibration and sampling gas paths, and significantly improves the accuracy and stability of the calibration.

[0016] Further, the zero gas inlet and the distance gas inlet of the multi-channel gas divider are respectively provided with piezoelectric drive proportional valves.

[0017] The beneficial effect of the further scheme is that the piezoelectric drive proportional valves are arranged at the zero gas inlet and the distance gas inlet of the multi-channel gas divider, which can realize high-precision control of the flow rates of the zero gas and the distance gas, ensure the accuracy of the proportion of the mixed gas, and generate stable calibration gas that meets the target concentration.

[0018] Further, the outlet of the multi-channel gas divider is provided with a spiral turbulent flow generator, the guide vane angle of the spiral turbulent flow generator is a set angle range, and the set angle range is 45°±2°.

[0019] The beneficial effect of the further scheme is that the guide vane angle of the spiral turbulent flow generator is set within the range of 45°±2°, which can generate strong turbulence when the gas flows out, further improve the uniformity of the gas, reduce the calibration error caused by uneven gas, and enhance the reliability and accuracy of the calibration result.

[0020] Further, the gas path control module comprises a gas pump and a gas path control assembly, the gas pump is connected with the flexible gas bag, the gas path control assembly comprises a first stop valve connected in series between the flexible gas bag and a multi-channel gas divider, a second stop valve connecting the gas pump and the flexible gas bag, and a three-way reversing valve arranged at the exhaust port of the gas pump; The gas path control assembly is configured to switch the gas path mode based on the gas path mode control signal sent by the controller. The gas pump is configured to pump gas into or out of the flexible gas bag.

[0021] The beneficial effects of the above further scheme are that the gas path control module realizes precise regulation of the gas pressure in the flexible gas bag. Specifically, the gas pump is connected with the flexible gas bag, and the pressure in the gas bag can be adjusted by pumping in or out of the gas, so as to ensure that the gas in the gas bag is in an ideal pressureless sampling environment. The first stop valve, the second stop valve and the three-way reversing valve in the gas path control assembly work cooperatively, and flexibly switch the inflation mode, the emptying mode and the purging mode according to the gas path mode control signal sent by the controller. This not only effectively solves the problem of pressure difference between the calibration gas path and the sampling gas path, but also unifies the flow providing mode, significantly improving the accuracy and reliability of calibration.

[0022] Further, the controller comprises: The timing logic unit is configured to control the working mode of the gas path control assembly to be the inflation mode in the pre-purification stage, control the gas pump to inflate the flexible gas bag based on a first set gas pump flow rate until the pressure in the flexible gas bag is greater than a first set pressure threshold, and control the gas pump to dynamically slow down based on a set dynamic slow-down strategy. Control the working mode of the gas path control assembly to be the emptying mode and control the gas pump to start according to a second set gas pump flow rate, and after the pressure in the flexible gas bag is not greater than a second set pressure threshold, control the working mode of the gas path control assembly to be the purging mode, and control the gas pump to start according to a third set gas pump flow rate based on a set first time, the second set gas pump flow rate is greater than the third set gas pump flow rate, the set first pressure threshold is greater than the set second pressure threshold, and the set first pressure threshold is a set target pressure threshold. In the dynamic gas distribution stage, based on a set target concentration, calculate the flow information of zero gas and span gas, control the working mode of the gas path control assembly to be the gas distribution mode, and based on the flow information, control the multi-channel gas divider to mix zero gas and span gas. During the calibration execution phase, the concentration information of the calibration gas in the flexible gas bag is acquired in real time, the working mode of the gas path control component is controlled to be calibration mode, and based on the concentration information of the calibration gas, the emission analyzer to be calibrated is controlled to sample the calibration gas and acquire the concentration information output by the emission analyzer to be calibrated; based on the concentration information output by the emission analyzer to be calibrated, the target concentration information, the set temperature compensation algorithm and nonlinear correction algorithm, a calibration curve is generated.

[0023] The beneficial effects of adopting the above-mentioned further solutions are: The controller's timing logic unit enables efficient cleaning of the flexible air bag during the pre-purification stage. First, by switching the control air path component to inflation mode, the inflation speed is gradually increased before reaching the predetermined pressure through precise control of the air pump flow, and a dynamic deceleration measure is implemented when approaching the target pressure. Then, by switching the control air path component to purging mode, the pressure inside the air bag is rapidly reduced to below the second pressure threshold using a larger second-set air pump flow, ensuring that residual gas is fully discharged. Subsequently, a purging mode is entered, using a lower third-set air pump flow to introduce zero air for flushing, further removing any remaining impurities and providing a clean environment for subsequent calibration.

[0024] During the dynamic gas mixing phase, the timing logic unit accurately calculates the ratio of zero gas and metering gas based on the target concentration, guiding the multi-channel gas divider to complete the mixing operation.

[0025] Once the calibration process begins, the unit continuously monitors the gas concentration changes within the flexible gas bag. Once the concentration stabilizes, it immediately instructs the emission analyzer to begin sampling. Furthermore, it comprehensively considers the differences between actual and expected target values, as well as the influence of external temperature conditions, using predefined temperature compensation and nonlinear correction algorithms to adjust and optimize the obtained data. Ultimately, it yields a more accurate and reliable calibration curve for subsequent analysis and evaluation.

[0026] Furthermore, the sequential logic unit is also used to perform the following steps: Step S41: In the post-processing stage, the working mode of the air path control component is controlled to be the venting mode, and the air pump is controlled to start according to the first set air pump flow rate based on the set second time, wherein the set second time is less than the set first time. Step S42: Control the working mode of the air circuit control component to purge mode. When the pressure of zero air filling in the flexible air bag is the third pressure threshold, the third pressure threshold is greater than the first pressure threshold. Step S43: Repeat steps S41 to S42 until the set number of cycles are performed to obtain the concentration information inside the flexible air bag.

[0027] The beneficial effects of adopting the above-mentioned further solution are as follows: In the post-processing stage, the control gas path component is first switched to the evacuation mode, and air is evacuated at a first set air pump flow rate for a set second time. This operation can quickly reduce the pressure inside the flexible gas bag, ensuring that residual gas is effectively discharged. Then, the system switches to the purging mode, filling the flexible gas bag with zero gas until a third pressure threshold is reached. This process displaces residual gas inside the gas bag, further reducing impurity content. Repeating the above steps for a specified number of cycles can thoroughly remove residual substances from the gas bag, ensuring the purity of the internal environment of the gas bag before the next calibration, thereby improving the accuracy and reliability of the calibration.

[0028] Furthermore, the controller also includes: The pressure closed-loop control unit is used to acquire the pressure inside the flexible air bag in real time, generate a pressure control signal based on the pressure information, a preset PID algorithm and a target pressure threshold, and control the gas supply flow of the multi-channel gas divider based on the pressure control signal to adjust the gas pressure inside the flexible air bag. The fault diagnosis unit is used to calculate the airtightness index of the flexible airbag based on the pressure information and volume of the flexible airbag; if the airtightness index of the flexible airbag is greater than the set airtightness index threshold, the alarm is activated.

[0029] The beneficial effects of adopting the above-mentioned further solution are: the pressure closed-loop control unit uses the pressure control signal generated by the PID algorithm to precisely regulate the operation of the air pump, realizing dynamic balance management of the gas pressure inside the flexible air bag. The fault diagnosis unit calculates the airtightness index to provide early warning of potential sealing problems, and can issue an alarm in a timely manner when there is a risk of leakage in the gas path, ensuring the reliability and safety of the data during the calibration process. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a calibration device for an automotive emissions analysis system according to an embodiment of the present invention; Figure 2 A schematic diagram illustrating the structure of the controller in a calibration device for an automotive emissions analysis system provided in one embodiment of the present invention; Figure 3 A schematic diagram of the structure of a calibration device for an automotive emissions analysis system provided in another embodiment of the present invention; Figure 4 A schematic diagram of the air circuit control component of a calibration device for an automotive emissions analysis system in an air-filling mode, provided as another embodiment of the present invention; Figure 5 A schematic diagram of the venting mode of the gas path control component of a calibration device for an automotive emissions analysis system provided in another embodiment of the present invention; Figure 6 A schematic diagram of the air circuit control component of a calibration device for an automotive emissions analysis system in purge mode, provided as another embodiment of the present invention; Figure 7 A schematic diagram of the air circuit control component of a calibration device for an automotive emissions analysis system, provided in another embodiment of the present invention, in the mode of air distribution. Figure 8 A schematic diagram of the calibration mode of the air circuit control component of a calibration device for an automotive emissions analysis system provided in another embodiment of the present invention; Labeling Explanation: 1. Flexible air bag; 2. Multi-channel gas divider; 3. Air pump; 4. First shut-off valve; 5. Second shut-off valve; 6. Three-way directional valve; 7. Controller; 8. Pressure sensor; 9. Pressure gauge; 10. Inlet of the analyzer to be calibrated; 11. Filter; 12. Silencer; 13. Fourth shut-off valve; 14. Fifth shut-off valve; 15. Sixth shut-off valve; 16. Seventh shut-off valve; 17. Eighth shut-off valve; 18. Throttling valve. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the appendices in the embodiments of this application will be described below. Figures 1 to 8 The technical solutions in the embodiments of this application are clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0033] like Figure 1 and Figure 2 As shown, a calibration device for an automotive emission analysis system includes a flexible gas bag 1, a multi-channel gas divider 2, an air path control module, and a controller 7. The air path control module is electrically connected to the controller 7. The outlet of the multi-channel gas divider 2 is connected to the inlet of the flexible gas bag 1. The outlet of the flexible gas bag 1 is connected to the air path control module through a pipeline. The flexible gas bag 1 is also connected to the sampling port of the emission analyzer to be calibrated through a pipeline.

[0034] Among them, the multi-channel gas divider 2 is used to mix zero gas and measuring gas based on preset target concentration information to obtain calibration gas of known concentration, and deliver the calibration gas to the flexible gas bag 1; the target concentration information includes the ratio of zero gas and measuring gas. Flexible gas bag 1 is used to store the calibration gas and simulate a pressureless sampling environment; The controller 7 is used to select the gas path mode based on the set calibration control process; The gas path control module is used to adjust the pressure of the flexible gas bag 1 based on a set gas path mode. The gas path mode is any one of the following: inflation mode, evacuation mode, and purging mode. The inflation mode represents the mode of filling the flexible gas bag 1 with external gas. The evacuation mode represents the mode of pumping the gas in the flexible gas bag 1 to the external environment. The purging mode represents the mode of circulating and conveying zero gas to flush each pipeline and the flexible gas bag 1. The inflation mode represents the mode of driving the mixed gas to be delivered to the flexible gas bag 1. The calibration mode represents the mode of sampling the calibration gas in the flexible gas bag 1. The controller 7 is further configured to, when the pressure inside the flexible air bag 1 reaches a set target pressure threshold, acquire in real time the concentration information of the calibration gas inside the flexible air bag 1, control the emission analyzer to be calibrated to sample the calibration gas based on the concentration information of the calibration gas, and acquire the concentration information output by the emission analyzer to be calibrated; and generate a calibration curve based on the concentration information output by the emission analyzer to be calibrated, the target concentration information, the set temperature compensation algorithm and the nonlinear correction algorithm.

[0035] This calibration device utilizes a flexible gas bag 1 to simulate a real pressureless sampling environment, meeting calibration requirements while ensuring the accuracy of the simulated environment. A multi-channel gas divider 2 ensures that the zero gas and measuring gas are precisely mixed according to preset target concentration information, generating stable calibration gas and providing strong support for high-precision calibration. The gas path control module supports inflation, evacuation, and purging modes, enabling flexible control of the pressure inside the flexible gas bag 1 and effectively cleaning the pipeline, reducing the impact of residual gas on subsequent calibrations. This makes the calibration process more automated and efficient, reducing errors caused by human operation. The intelligent controller 7 intelligently manages the entire calibration process, including real-time monitoring of the gas concentration inside the flexible gas bag 1, adjusting the working state of the gas path control module according to preset algorithms, and generating calibration curves by integrating multiple factors. This makes the calibration process more automated and orderly, preventing calibration deviations caused by gas path problems.

[0036] In this embodiment, the flexible air bag 1 is made of a double-layer fluorinated ethylene propylene copolymer (FEP) film. An X-shaped guide tube is installed inside the flexible air bag 1. The input end of the X-shaped guide tube is connected to the multi-channel gas divider 2, and the X-shaped guide tube is connected to the outlet air pipe of the flexible air bag 1. Air outlet holes are evenly distributed on the X-shaped guide tube, and the inner wall of the X-shaped guide tube is coated with a nano-ceramic coating. A pressure sensor 8 is also installed in the flexible air bag 1. The pressure sensor 8 is electrically connected to the controller 7. The pressure sensor 8 is used to detect the pressure information in the flexible air bag 1 and sends the pressure information to the controller 7 in real time.

[0037] FEP is a material with excellent corrosion resistance and high-pressure resistance, capable of withstanding various gas and pressure changes that may be encountered during calibration. The double-layer design enhances the strength and durability of the airbag, ensuring its reliability during use. This allows the flexible airbag 1 to withstand a burst pressure of no less than 2500 Pa, ensuring that it will not rupture under high pressure and guaranteeing the safety of the calibration process.

[0038] The flexible gas bag 1 has a volume design of 15L ± 0.5L. This is sufficient to hold enough gas for calibration without being too large to cause operational inconvenience. The X-shaped guide tube design allows for uniform distribution of the mixed gas within the gas bag, reducing concentration gradients and improving calibration accuracy. The evenly distributed gas outlets on the guide tube further promote thorough gas mixing. The inner wall is coated with a nano-ceramic coating to reduce gas adsorption rate and minimize its impact on the calibration gas concentration. Simultaneously, the X-shaped guide tube also supports the flexible gas bag 1, preventing deformation or damage during use.

[0039] Pressure sensor 8 monitors the pressure changes inside the air bag in real time, and together with controller 7, achieves precise pressure control to ensure that the pressure inside the air bag is maintained within the target range, thereby eliminating the pressure difference between the calibration and sampling air paths and significantly improving the accuracy and stability of calibration.

[0040] Optionally, the zero gas inlet and the measuring gas inlet of the multi-channel gas divider 2 are each equipped with a piezoelectrically driven proportional valve, with a flow rate adjustment resolution of 0.1 mL / min and a mixing ratio error ≤ ±0.8%. The piezoelectrically driven proportional valve features fast response and high adjustment accuracy, meeting the requirements of high-precision calibration for gas flow control. The outlet of the multi-channel gas divider 2 is equipped with a spiral turbulence generator, the guide vane of which has an inclination angle within a set range of 45° ± 2°.

[0041] In this embodiment, the gas mixing uniformity of the helical turbulence generator needs to be verified during use. First, nine sampling points are set up inside the flexible gas bag 1, and the concentration at each point is simultaneously detected using a mass spectrometer. Then, the relative standard deviation (RSD) is calculated based on the detected concentrations at each point. The formula for RSD is RSD = (σ / μ) × 100%. The calculated RSD value is used to evaluate the gas mixing uniformity generated by the helical turbulence generator within the gas bag. Typically, an RSD < 1.2% is required, meaning that the difference in concentration between points is within an acceptable range, indicating a high degree of gas mixing uniformity.

[0042] High-precision flow control is provided by a piezoelectrically driven proportional valve, which can accurately control the mixing ratio of zero gas and measuring gas, ensuring the accurate concentration of the mixed gas and improving calibration accuracy. The spiral turbulence generator effectively increases gas turbulence and improves gas uniformity, making the calibration gas concentration more precise and controllable, and reducing calibration errors caused by gas inhomogeneity.

[0043] The gas path control module includes an air pump 3 and a gas path control component. The air pump 3 is connected to the flexible air bag 1 through a pipeline. The gas path control component includes a first shut-off valve 4 connected in series between the flexible air bag 1 and the multi-channel gas divider 2, a second shut-off valve 5 connecting the air pump 3 and the flexible air bag 1, and a three-way reversing valve 6 located at the exhaust port of the air pump 3.

[0044] Air pump 3 is a diaphragm air pump made of perfluoroether rubber, with stepless flow rate adjustment (5-30L / min). Perfluoroether rubber has good corrosion resistance and wear resistance, ensuring that air pump 3 maintains stable performance during long-term use and meets the needs of different calibration stages. It works in conjunction with a three-way reversing valve 6 (response time ≤50ms) to switch between charging, purging, and purging modes. The response time of the first shut-off valve 4, the second shut-off valve 5, and the reversing valve is designed to be ≤50ms.

[0045] The gas path control component is used to switch the gas path mode based on the gas path mode control signal sent by the controller 7. The air pump 3 is used to pump gas into or extract gas into the flexible air bag 1 to adjust the gas pressure inside the flexible air bag 1.

[0046] Connected to the flexible gas bag 1 by the air pump 3, the pressure inside the gas bag can be adjusted by pumping in or extracting gas, thus ensuring that the gas inside the gas bag is in an ideal pressureless sampling environment. The first shut-off valve 4, the second shut-off valve 5, and the three-way reversing valve 6 in the gas path control assembly work together, flexibly switching between inflation, purging, and cleaning modes based on the gas path mode control signal issued by the controller 7. This not only effectively solves the pressure difference problem between the calibration gas path and the sampling gas path but also unifies the flow rate supply method, significantly improving the accuracy and reliability of calibration.

[0047] In this embodiment of the application, the controller 7 includes: The timing logic unit is used to control the working mode of the air path control component to the inflation mode during the pre-purification stage, control the air pump 3 to inflate the flexible air bag 1 based on the first set air pump flow rate until the pressure inside the flexible air bag 1 is greater than the set first pressure threshold, and control the air pump 3 to dynamically reduce the speed based on the set dynamic speed reduction strategy. The working mode of the air path control component is controlled to be the purging mode and the air pump 3 is controlled to start according to the second set air pump flow rate until the pressure in the flexible air bag 1 is not greater than the set second pressure threshold. Then, the working mode of the air path control component is controlled to be the purging mode and the air pump 3 is controlled to start according to the third set air pump flow rate based on the set first time. The second set air pump flow rate is greater than the third set air pump flow rate. The set first pressure threshold is greater than the set second pressure threshold. The set first pressure threshold is the set target pressure threshold. During the dynamic gas mixing phase, based on the set target concentration, the flow information of zero gas and measuring gas is calculated, the working mode of the gas path control component is controlled to be the gas mixing mode, and based on the flow information, the multi-channel gas divider 2 is controlled to mix zero gas and measuring gas. During the calibration execution phase, the concentration information of the calibration gas in the flexible gas bag 1 is acquired in real time, the working mode of the gas path control component is controlled to be calibration mode, and based on the concentration information of the calibration gas, the emission analyzer to be calibrated is controlled to sample the calibration gas and acquire the concentration information output by the emission analyzer to be calibrated; based on the concentration information output by the emission analyzer to be calibrated, the target concentration information, the set temperature compensation algorithm and nonlinear correction algorithm, a calibration curve is generated.

[0048] The sequential logic unit is also used to perform the following steps: Step S41: In the post-processing stage, the working mode of the air circuit control component is controlled to be the venting mode, and the air pump 3 is controlled to start according to the first set air pump flow rate based on the set second time, wherein the set second time is less than the set first time. Step S42: Control the working mode of the air circuit control component to purge mode. When the pressure of zero air filling in the flexible air bag 1 is the third pressure threshold, the third pressure threshold is greater than the first pressure threshold. Step S43: Repeat steps S41 to S42 until the set number of cycles are performed to obtain the concentration information inside the flexible air bag 1.

[0049] The above implementation methods will be described in detail below.

[0050] During the pre-purification stage, the controller 7 opens the first shut-off valve 4 and switches the three-way reversing valve 6 to the inflation position, controlling the air pump 3 to increase the air pump flow rate to 5L / min at a rate of 0.5L / s. When the air bag pressure is greater than 100Pa, the air supply rate is reduced according to u(k)=0.8×ΔP(k) to ensure pressure stability and avoid overshoot.

[0051] The controller 7 first closes the first shut-off valve 4, opens the second shut-off valve 5 and the three-way reversing valve 6 to the vent position, and starts the air pump 3 to pump the flexible air bag 1 at a flow rate of 20L / min until the pressure is ≤10Pa. Subsequently, when the pressure of the flexible air bag 1 drops to 10Pa, the controller 7 switches the three-way reversing valve 6 to the purge position and controls the multi-channel gas divider 2 to introduce zero gas at a flow rate of 10L / min for 40 seconds. The gas flow path is: zero gas source, multi-channel gas divider 2, first shut-off valve 4, flexible air bag 1, second shut-off valve 5, air pump 3, three-way reversing valve 6, and finally vents through the air pump 3.

[0052] During the dynamic gas distribution phase, controller 7 calculates the flow information of zero gas and measuring gas based on the set target concentration.

[0053] The calculation formula is: ; ; in, =5L / min, The concentration of the gas is measured at a distance.

[0054] It should be noted that during the dynamic gas mixing phase, when the rate of change of the ambient temperature exceeds a certain limit, such as when the rate of change of the ambient temperature is >1℃ / min, the dual compensation mode is automatically activated. Based on the dual compensation mode and the target concentration information, the new target concentration information after compensation is calculated to avoid the temperature environment from affecting the accuracy of the measurement data.

[0055] The calculation formula for the dual compensation mode is: ; in, For the new target concentration information after compensation, The target concentration information before compensation, where γ is a constant, set to 0.0002 / (℃·min). It represents the cumulative change in ambient temperature over time.

[0056] During the calibration execution phase, when the standard deviation of gas concentration fluctuation σ in the gas bag is less than 0.5%C_t, the emission analyzer to be calibrated is controlled to sample the calibration gas to ensure the stability of the calibration data.

[0057] After acquiring the output value of the analyzer, the controller 7 obtains the concentration information output by the emission analyzer to be calibrated, and generates a calibration curve based on the concentration information output by the emission analyzer to be calibrated, the target concentration information, the set temperature compensation algorithm and nonlinear correction algorithm.

[0058] The calibration curve generation includes nonlinear correction and employs cubic polynomial fitting: ; in, This is the final concentration value after nonlinear correction. To obtain the new target concentration information after compensation, coefficients a, b, c, and d are determined by fitting multi-point calibration data.

[0059] In the post-treatment stage, the second shut-off valve 5 is opened and the three-way reversing valve 6 is switched to the venting position. The controller 7 controls the air pump 3 to vent the flexible air bag 1 at a flow rate of 30L / min for 35 seconds. Three purging cycles are performed, each time the air is filled to 500Pa and then evacuated. The final residual concentration is <0.5ppm.

[0060] After inflating the air bag to a certain pressure, close all valves and let it stand for 300 seconds, observing the pressure change. If the pressure rises by more than 15 Pa within 300 seconds, the seal is considered to have failed, and the air circuit needs to be checked and repaired immediately.

[0061] As another embodiment of this application, the difference from the above embodiment is the air path control component in the calibration device of the vehicle emission analysis system.

[0062] like Figure 3 As shown, the calibration device for the vehicle emission analysis system also includes a filter 11 and a muffler 12. The filter 11 and the muffler 12 are respectively connected to the air pump 3 through pipelines. The air circuit control component includes a fourth shut-off valve 13, a fifth shut-off valve 14, a sixth shut-off valve 15, a seventh shut-off valve 16, and an eighth shut-off valve 17. The fourth shut-off valve 13 is installed on the pipeline between the multi-channel gas divider 2 and the flexible air bag 1. The fifth shut-off valve 14 is installed on the pipeline between the flexible air bag 1 and the air pump 3. The sixth shut-off valve 15 is installed on the pipeline between the air pump 3 and the muffler 12. The seventh shut-off valve 16 is installed on the pipeline between the filter 11 and the air pump 3. The eighth shut-off valve 17 is installed on the pipeline connected in parallel with the pipeline where the air pump 3 is located.

[0063] Sequential logic units are used in the pre-cleaning stage, such as... Figure 4As shown, controller 7 controls the valves of the fourth shut-off valve 13, the sixth shut-off valve 15, the eighth shut-off valve 17 and the inlet 10 of the analyzer to be calibrated to be closed, and controls the valves of the fifth shut-off valve 14, the seventh shut-off valve 16 and the air inlet of the flexible air bag 1 to be open. The flow rate of air pump 3 is increased to 5L / min at a rate of 0.5L / s. When the air bag pressure is >100Pa, the air supply rate is reduced according to u(k)=0.8×ΔP(k). After that, as Figure 5 As shown, the controller 7 controls the valves at the air inlet of the flexible air bag 1, the sixth shut-off valve 15 and the eighth shut-off valve 17 to be in the open state, and controls the valves at the fourth shut-off valve 13, the fifth shut-off valve 14, the seventh shut-off valve 16 and the valve at the inlet of the analyzer to be calibrated to be in the closed state. The air pump 3 is started to draw air from the air bag at a flow rate of 20L / min until the pressure is ≤10Pa. After that, as Figure 6 As shown, controller 7 controls the valves at the inlet of flexible air bag 1, the fourth shut-off valve 13, the fifth shut-off valve 14, and the sixth shut-off valve 15 to be in the open state, and controls the valves at the inlet 10 of the analyzer to be calibrated, the seventh shut-off valve 16, and the eighth shut-off valve 17 to be in the closed state. Zero gas is introduced at a flow rate of 10L / min for 40 seconds. The path is: zero gas source, gas divider, fourth shut-off valve 13, flexible air bag 1, fifth shut-off valve 14, sixth shut-off valve 15 to the exhaust port.

[0064] During the dynamic gas distribution phase, controller 7 calculates the flow information of zero gas and metering gas based on the set target concentration, and then, as follows: Figure 7 As shown, the controller 7 controls the fourth shut-off valve 13 to be in the open state, and at the same time controls the valve of the air inlet of the flexible air bag 1 to be in the open state, and controls the valves of the fifth shut-off valve 14, the sixth shut-off valve 15, the seventh shut-off valve 16, the eighth shut-off valve 17 and the valve of the inlet 10 of the analyzer to be calibrated to be in the closed state, so as to inflate the flexible air bag 1 until the pressure of the flexible air bag 1 reaches the target pressure threshold. During the calibration execution phase, such as Figure 8 As shown, when the standard deviation of gas concentration fluctuation σ in the flexible gas bag 1 is less than 0.5%C_t, the controller 7 controls the valve of the inlet 10 of the analyzer to be calibrated to open, and at the same time controls the emission analyzer to be calibrated to sample the calibration gas to ensure the stability of the calibration data.

[0065] After acquiring the output value of the analyzer, the controller 7 obtains the concentration information output by the emission analyzer to be calibrated, and generates a calibration curve based on the concentration information output by the emission analyzer to be calibrated, the target concentration information, the set temperature compensation algorithm and nonlinear correction algorithm.

[0066] In the post-processing stage, the controller 7 controls the sixth shut-off valve 15 and the eighth shut-off valve 17 to be in the open state, and controls the fourth shut-off valve 13, the fifth shut-off valve 14 and the seventh shut-off valve 16. The controller 7 controls the air pump 3 to evacuate the flexible air bag 1 at a flow rate of 30L / min for 35 seconds. Three purging cycles are performed, each time the air is filled to zero gas to 500Pa and then evacuated, and the final residual concentration is <0.5ppm.

[0067] After inflating the air bag to a certain pressure, close all valves and let it stand for 300 seconds, observing the pressure change. If the pressure rises by more than 15 Pa within 300 seconds, the seal is considered to have failed, and the air circuit needs to be checked and repaired immediately.

[0068] It should be noted that a throttle valve 18 is also provided between the gas divider and the fourth shut-off valve 13. The throttle valve is used to regulate and limit the flow rate of the calibration gas. A pressure gauge 9 is also provided in the gas line to display the pressure information in the flexible gas bag 1.

[0069] Optionally, a pressure closed-loop control unit is used to acquire the pressure information of the flexible air bag 1 in real time, generate a pressure control signal based on the pressure information, a preset PID algorithm and a target pressure threshold, and control the gas supply flow of the multi-channel gas divider 2 based on the pressure control signal to adjust the gas pressure in the flexible air bag 1. The fault diagnosis unit is used to calculate the airtightness index of the flexible airbag 1 based on the pressure and volume inside the flexible airbag 1; if the airtightness index of the flexible airbag 1 is greater than the set airtightness index threshold, the alarm is controlled to sound.

[0070] In this embodiment, the control parameters of the PID algorithm are set to K_p=3.2, K_i=0.5, and K_d=1.8 to ensure pressure fluctuation ≤±5Pa and improve calibration accuracy. By calculating the current error, historical error, and their changing trends, the increment of the PID control quantity is dynamically adjusted to achieve the target flow rate and pressure.

[0071] In this embodiment, the fault diagnosis unit calculates the airtightness index L=(∆P∙V) / (∆t∙P_amb) in real time, and triggers a level three alarm when L>0.05L / h.

[0072] In this embodiment, the control system is also equipped with a human-machine interface to display real-time data during the calibration process, such as pressure, flow rate, and concentration, so that operators can monitor the calibration process.

[0073] The pressure closed-loop control unit uses a pressure control signal generated by a PID algorithm to precisely regulate the operation of the air pump 3, achieving dynamic balance management of the gas pressure inside the flexible air bag 1. The fault diagnosis unit calculates the airtightness index to provide early warning of potential sealing problems, and can issue timely alarms when there is a risk of leakage in the gas path, ensuring the reliability and safety of the calibration data.

[0074] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0075] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing application concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions claimed in this application.

Claims

1. A calibration device for an automotive emissions analysis system, characterized in that, It includes a flexible gas bag (1), a multi-channel gas divider (2), a gas path control module and a controller (7). The gas path control module is electrically connected to the controller (7). The outlet of the multi-channel gas divider (2) is connected to the inlet of the flexible gas bag (1). The outlet of the flexible gas bag (1) is connected to the gas path control module through a pipeline. The flexible gas bag (1) is also connected to the sampling port of the emission analyzer to be calibrated through a pipeline. The multi-channel gas divider (2) is used to mix zero gas and measuring gas based on preset target concentration information to obtain calibration gas of known concentration, and deliver the calibration gas to the flexible gas bag (1). The flexible gas bag (1) is used to store the calibration gas and simulate a pressureless sampling environment; The controller (7) is used to select the gas path mode based on the set calibration control process; The gas path control module is used to adjust the pressure of the flexible gas bag (1) based on the selected gas path mode. The gas path mode is any one of the following: inflation mode, purging mode, purging mode, gas distribution mode, and calibration mode. The inflation mode represents the mode of filling the flexible gas bag (1) with external gas. The purging mode represents the mode of pumping the gas in the flexible gas bag (1) to the external environment. The purging mode represents the mode of circulating and conveying zero gas to flush each pipeline and the flexible gas bag (1). The gas distribution mode represents the mode of driving the mixed gas to be delivered to the flexible gas bag (1). The calibration mode represents the mode of sampling the calibration gas in the flexible gas bag (1). The controller (7) is also used to acquire the concentration information of the calibration gas in the flexible air bag (1) in real time when the pressure in the flexible air bag (1) reaches the set target pressure threshold, and control the emission analyzer to be calibrated to sample the calibration gas based on the concentration information of the calibration gas, and acquire the concentration information output by the emission analyzer to be calibrated. Based on the concentration information output by the emission analyzer to be calibrated, the target concentration information, the set temperature compensation algorithm, and the nonlinear correction algorithm, a calibration curve for the emission analyzer to be calibrated is generated.

2. The calibration device for an automotive emissions analysis system according to claim 1, characterized in that, The flexible air bag (1) is made of a double-layer fluorinated ethylene propylene copolymer film.

3. The calibration device for an automotive emissions analysis system according to claim 1, characterized in that, The flexible air bag (1) is provided with an X-shaped guide tube. The input end of the X-shaped guide tube is connected to the multi-channel gas divider (2). The X-shaped guide tube is provided with air outlet holes evenly distributed on it. The X-shaped guide tube is connected to the outlet air pipe of the flexible air bag (1).

4. A calibration device for an automotive emissions analysis system according to any one of claims 1 to 3, characterized in that, The flexible air bag (1) is also equipped with a pressure sensor (8), which is connected to the controller (7) and is used to detect the pressure inside the flexible air bag (1).

5. The calibration device for an automotive emissions analysis system according to claim 1, characterized in that, The zero gas inlet and the distance gas inlet of the multi-channel gas divider (2) are respectively equipped with piezoelectric proportional valves.

6. The calibration device for an automotive emissions analysis system according to claim 1, characterized in that, The multi-channel gas divider (2) is equipped with a spiral turbulence generator at its outlet. The guide vane of the spiral turbulence generator has an inclination angle within a set angle range of 45°±2°.

7. The calibration device for an automotive emissions analysis system according to claim 1, characterized in that, The gas path control module includes an air pump (3) and a gas path control component. The air pump (3) is connected to the flexible air bag (1). The gas path control component includes a first shut-off valve (4) connected in series between the flexible air bag (1) and the multi-channel gas divider (2), a second shut-off valve (5) connecting the air pump (3) and the flexible air bag (1), and a three-way reversing valve (6) disposed at the exhaust port of the air pump (3). The gas path control component is used to switch the gas path mode based on the gas path mode control signal sent by the controller (7); The air pump (3) is used to pump gas into or extract gas into the flexible air bag (1).

8. The calibration device for an automotive emissions analysis system according to claim 7, characterized in that, The controller (7) includes: The timing logic unit is used to control the working mode of the air path control component to the inflation mode during the pre-purification stage, control the air pump (3) to inflate the flexible air bag (1) based on the first set air pump flow rate until the pressure inside the flexible air bag (1) is greater than the set first pressure threshold, and control the air pump (3) to dynamically reduce the speed based on the set dynamic speed reduction strategy. The working mode of the air path control component is controlled to be the purging mode and the air pump (3) is controlled to start according to the second set air pump flow rate until the pressure in the flexible air bag (1) is not greater than the set second pressure threshold. Then, the working mode of the air path control component is controlled to be the purging mode and the air pump (3) is controlled to start according to the third set air pump flow rate based on the set first time. The second set air pump flow rate is greater than the third set air pump flow rate. The set first pressure threshold is greater than the set second pressure threshold. The set first pressure threshold is the set target pressure threshold. During the dynamic gas mixing stage, based on the set target concentration, the flow information of zero gas and measuring gas is calculated, the working mode of the gas path control component is controlled to be the gas mixing mode, and based on the flow information, the multi-channel gas divider (2) is controlled to mix zero gas and measuring gas. During the calibration execution phase, the concentration information of the calibration gas in the flexible gas bag (1) is acquired in real time, the working mode of the gas path control component is controlled to be calibration mode, and based on the concentration information of the calibration gas, the emission analyzer to be calibrated is controlled to sample the calibration gas and acquire the concentration information output by the emission analyzer to be calibrated; based on the concentration information output by the emission analyzer to be calibrated, the target concentration information, the set temperature compensation algorithm and nonlinear correction algorithm, a calibration curve is generated.

9. The calibration device for an automotive emissions analysis system according to claim 8, characterized in that, The sequential logic unit is also used to perform the following steps: Step S41, in the post-processing stage, the working mode of the air path control component is controlled to be the venting mode, and the air pump (3) is controlled to start according to the first set air pump flow rate based on the set second time, wherein the set second time is less than the set first time; Step S42: Control the working mode of the air path control component to purge mode. When the pressure of zero air filling in the flexible air bag (1) is the third pressure threshold, the third pressure threshold is greater than the first pressure threshold. Step S43: Repeat steps S41 to S42 until the set number of cycles are performed to obtain the concentration information inside the flexible air bag (1).

10. A calibration device for an automotive emissions analysis system according to claim 8, characterized in that, The controller (7) also includes: The pressure closed-loop control unit is used to acquire the pressure inside the flexible air bag (1) in real time, generate a pressure control signal based on the pressure, a preset PID algorithm and a target pressure threshold, and control the gas supply flow of the multi-channel gas divider (2) based on the pressure control signal to adjust the pressure inside the flexible air bag (1). The fault diagnosis unit is used to calculate the air tightness index of the flexible air bag (1) based on the pressure and volume inside the flexible air bag (1); if the air tightness index of the flexible air bag (1) is greater than the set air tightness index threshold, the alarm is controlled to sound.

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