Automobile carbon tank desorption flow detection method and system and electronic equipment

Abstract

The invention provides an automobile carbon tank desorption flow detection method and system and electronic equipment, and is applied to a controller of the automobile carbon tank desorption flow detection system.The method comprises the steps that a flow data collection module is used for collecting the desorption flow rate in a detected automobile carbon tank so as to obtain the first carbon tank desorption flow under the whole automobile working condition; acquiring the carbon tank flow of the tested vehicle under different engine control parameters by using an electronic injection parameter acquisition module, and determining the desorption flow of a second carbon tank according to the carbon tank flow; and correcting the desorption flow of the first carbon tank by using the desorption flow correction model and the desorption flow of the second carbon tank so as to determine the final desorption flow of the carbon tank of the tested vehicle. By adopting the automobile carbon tank desorption flow detection method, the automobile carbon tank desorption flow detection system and the electronic equipment, the problem that the measurement accuracy of a vortex street type flow meter on the carbon tank desorption flow is low at low pressure and low flow velocity is solved.

Description

Technical Field

[0001] The present application relates to the field of automobile detection technology, and in particular to a method, system and electronic equipment for detecting the desorption flow rate of an automobile carbon canister. Background Art

[0002] With the rapid development of the automobile industry, people have higher and higher requirements for automobile evaporative pollutant emissions, and the main source of evaporative pollutants is the fuel system. During the development stage of evaporative pollutant emissions, engineers use various methods to control and reduce pollutant sources such as engines, fuel tanks, and carbon canisters to design evaporative pollutant control systems, and control the adsorption and desorption of carbon canisters through different strategies to reduce the escape of fuel vapor to meet relevant regulatory requirements. In order to accurately determine the emission of evaporative pollutants, it is necessary to conduct detection tests on evaporative pollutant emissions during the development stage of evaporative pollutant emissions to determine the vehicle's carbon canister desorption flow rate. In the prior art, a vortex flowmeter is usually used in the vehicle environmental chamber to detect the carbon canister desorption flow rate.

[0003] However, when the vortex flowmeter is under low pressure and low flow rate, for example, below 0.14V, the rotational force of the gas passing through the vortex flowmeter is small. Due to the limitations of the vortex flowmeter's own characteristics, the rotation speed of the vortex flowmeter will slow down and the amplitude of the pulsating signal generated will be small, which will lead to the problem of low measurement accuracy of the vortex flowmeter for the carbon canister desorption flow rate under low pressure and low flow rate. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a method, system and electronic equipment for detecting the desorption flow of an automobile carbon canister, so as to solve the problem of low measurement accuracy of the desorption flow of the carbon canister by a vortex flowmeter at low pressure and low flow rate.

[0005] In the first aspect, the embodiment of the present application provides a method for detecting the desorption flow rate of a carbon canister of an automobile, which is applied to a controller of a desorption flow rate detection system of a carbon canister of an automobile. The desorption flow rate detection system of the carbon canister of an automobile further includes an electromagnetic shielding module, a flow data acquisition module, and an EFI parameter acquisition module. The flow data acquisition module includes a flow meter, which is arranged in the electromagnetic shielding module, including:

[0006] The flow data acquisition module is used to collect the desorption flow rate in the carbon canister of the tested vehicle to obtain the desorption flow rate of the first carbon canister under the whole vehicle working condition;

[0007] The carbon canister flow rate of the tested vehicle under different engine control parameters is obtained by using the EFI parameter acquisition module, and the desorption flow rate of the second carbon canister is determined according to the carbon canister flow rate;

[0008] The desorption flow rate correction model and the second carbon canister desorption flow rate are used to correct the first carbon canister desorption flow rate to determine the final carbon canister desorption flow rate of the tested vehicle.

[0009] Optionally, the desorption flow rate of the first carbon canister is corrected using a desorption flow rate correction model and the desorption flow rate of the second carbon canister, including: constructing a desorption flow rate correction model based on the degree of influence of multiple precision influencing factors on the final carbon canister desorption flow rate; substituting the first carbon canister desorption flow rate and the second carbon canister desorption flow rate into the desorption flow rate correction model to determine the output result of the desorption flow rate correction model as the final carbon canister desorption flow rate.

[0010] Optionally, based on the degree of influence of multiple precision influencing factors on the final carbon canister desorption flow, a desorption flow correction model is constructed, including: determining an initial correction coefficient corresponding to each precision influencing factor based on the degree of influence of each precision influencing factor on the final carbon canister desorption flow; determining a final correction coefficient based on the initial correction coefficient and the weighted value corresponding to each precision influencing factor; and constructing a desorption flow correction model based on the final correction coefficient, the first carbon canister desorption flow and the second carbon canister desorption flow.

[0011] Optionally, determining the initial correction coefficient corresponding to each precision influencing factor includes: determining the initial correction value of each precision influencing factor according to the degree of influence of each precision influencing factor on the final carbon canister desorption flow; and determining the initial correction coefficient corresponding to each precision influencing factor using the mean and standard deviation corresponding to all initial correction values.

[0012] Optionally, the desorption flow correction model is a model that uses the target second carbon canister desorption flow in the second carbon canister desorption flow to correct the corresponding carbon canister desorption flow in the first carbon canister desorption flow, and the target second carbon canister desorption flow is the carbon canister desorption flow measured at low pressure and low flow rate.

[0013] Optionally, the second carbon canister desorption flow rate is determined according to the carbon canister flow rate, including: integrating the carbon canister flow rate over time to obtain the carbon canister desorption mass; and determining the second carbon canister desorption flow rate using the carbon canister desorption mass.

[0014] Optionally, the desorption flow rate of the second carbon canister is determined by utilizing the desorption mass of the carbon canister, including: determining the desorption flow rate of the second carbon canister according to a ratio of the desorption mass of the carbon canister to the air density.

[0015] Optionally, the carbon canister flow rate of the tested vehicle under different engine control parameters is obtained by using the electronic fuel injection parameter acquisition module, including: using the electronic fuel injection parameter acquisition module to obtain the carbon canister flow rate of the engine under the solenoid valve opening.

[0016] In a second aspect, the embodiment of the present application further provides a vehicle carbon canister desorption flow detection system, the system comprising a controller, an electromagnetic shielding module, a flow data acquisition module, and an EFI parameter acquisition module, the flow data acquisition module comprising a flow meter, and the flow meter is arranged in the electromagnetic shielding module;

[0017] A controller, used to execute the above-mentioned gas canister desorption flow detection method;

[0018] The flow data acquisition module is connected to the carbon canister of the tested vehicle to obtain the desorption flow of the first carbon canister under the whole vehicle working condition;

[0019] The EFI parameter acquisition module is connected to the on-board self-diagnosis system of the tested vehicle to obtain the carbon canister flow rate of the tested vehicle under different engine control parameters;

[0020] The electromagnetic shielding module is used to eliminate the influence of vibration and electromagnetic field on the collection results of the flow meter.

[0021] In a third aspect, an embodiment of the present application further provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the steps of the above-mentioned automobile carbon canister desorption flow detection method are performed.

[0022] The embodiments of the present application bring the following beneficial effects:

[0023] The embodiments of the present application provide a method, system and electronic device for detecting the desorption flow of a first carbon canister and a second carbon canister, respectively, and correct part of the test data of the desorption flow of the first carbon canister through a desorption flow correction model and the desorption flow of the second carbon canister, so as to finally obtain an accurate desorption flow of the carbon canister, thereby improving the detection accuracy and stability of the desorption flow of the carbon canister of the measured vehicle under low pressure and low flow rate conditions. Compared with the automobile carbon canister desorption flow detection method in the prior art, the problem of low measurement accuracy of the desorption flow of the carbon canister by the vortex flowmeter under low pressure and low flow rate is solved.

[0024] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The structural schematic diagram of the automobile carbon canister desorption flow detection system provided in the embodiment of the present application is shown;

[0027] Figure 2 A front view of the electromagnetic shielding device provided in an embodiment of the present application is shown;

[0028] Figure 3 A top view of an electromagnetic shielding device provided in an embodiment of the present application is shown;

[0029] Figure 4 A flow chart of a method for detecting the desorption flow of a carbon canister of an automobile provided in an embodiment of the present application is shown;

[0030] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0031] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0032] It is worth noting that before the present application was filed, with the rapid development of the automobile industry, people had higher and higher requirements for automobile evaporative pollutant emissions, and the main source of evaporative pollutants is the fuel system. During the development stage of evaporative pollutant emissions, engineers used various methods to control and reduce pollutant sources such as engines, fuel tanks, and carbon canisters to design evaporative pollutant control systems, and controlled the adsorption and desorption of carbon canisters through different strategies to reduce the escape of fuel vapor to meet relevant regulatory requirements. In order to accurately determine the emission of evaporative pollutants, it is necessary to conduct detection tests on evaporative pollutant emissions during the development stage of evaporative pollutant emissions to determine the vehicle's carbon canister desorption flow rate. In the prior art, a vortex flowmeter is usually used in the vehicle environmental chamber to detect the carbon canister desorption flow rate, and the carbon canister desorption flow rate measured by the vortex flowmeter is expressed in the form of voltage. However, when the vortex flowmeter is under low pressure and low flow rate, for example, below 0.14V, the rotational force of the gas passing through the vortex flowmeter is small. Due to the limitations of the vortex flowmeter's own characteristics, the rotation speed of the vortex flowmeter will slow down and the amplitude of the pulsating signal generated will be small, which will lead to the problem of low measurement accuracy of the vortex flowmeter for the carbon canister desorption flow rate under low pressure and low flow rate.

[0033] Based on this, an embodiment of the present application provides a method for detecting the desorption flow rate of a carbon canister of an automobile, so as to improve the accuracy of the detection of the desorption flow rate of the carbon canister at low pressure and low flow rate.

[0034] The present application provides a method for detecting the desorption flow rate of a carbon canister of an automobile, which is applied to a desorption flow rate detection system of a carbon canister of an automobile. Figure 1 Let's introduce the automobile carbon canister desorption flow detection system.

[0035] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle carbon canister desorption flow detection system provided in an embodiment of the present application. Figure 1 As shown in , the automobile canister desorption flow detection system 10 includes a flow data acquisition module 100, an electromagnetic shielding module 200, an EFI parameter acquisition module 300, and a controller 400. The flow data acquisition module includes a data storage module 110, a flow display device 120, and a flow meter 130, and the flow meter 130 is disposed in the electromagnetic shielding module 200.

[0036] The flow meter 130 of the flow data acquisition module 100 is connected to the carbon canister 510 of the tested vehicle 500, and is used to obtain the first carbon canister desorption flow rate of the whole vehicle under working conditions;

[0037] The EFI parameter acquisition module 300 is connected to the on-board self-diagnosis system 520 of the tested vehicle 500, and is used to obtain the carbon canister flow rate of the tested vehicle under different engine control parameters;

[0038] The electromagnetic shielding module 200 is used to eliminate the influence of vibration and strong magnetic field on the collection results of the flow meter 130.

[0039] In addition, the flow meter 130 is also connected to the flow display device 120 and the data storage module 110 in sequence, and is used to send the collected results to the flow display device 120 for display, and store the collected data in the data storage module 110.

[0040] The EFI parameter acquisition module 300 is also connected to the controller 400 to transfer the carbon canister flow data acquired by the EFI parameter acquisition module 300 to the controller 400 for processing.

[0041] The controller 400 is connected to the EFI parameter acquisition module 300 and the flow data acquisition module 100, and is used to obtain the data collected by the flow meter 130 and the EFI parameter acquisition module 300, and perform processing corresponding to the automobile carbon canister desorption flow detection method.

[0042] The electromagnetic shielding module includes an electromagnetic shielding device, which can shield the influence of vibration and electromagnetic field on the flow meter. The electromagnetic shielding device includes a cabinet and a visual window, a cabinet door is arranged on the side of the cabinet, and a copper plate is covered on the visual window.

[0043] Refer to the following Figure 2 and Figure 3 Let's introduce the electromagnetic shielding device in detail.

[0044] Figure 2 FIG. 4 shows a front view of the electromagnetic shielding device provided in an embodiment of the present application. Figure 2 As shown, the electromagnetic shielding device includes a lock 301 , a buckle 302 , a side extension tube 303 , a viewing window 304 , a cabinet 305 , a buffer pad 306 , a hinge 307 , a copper plate 308 , a side air inlet 309 and an electromagnetic shielding net 310 .

[0045] Figure 3 FIG. 4 shows a top view of the electromagnetic shielding device provided in an embodiment of the present application. Figure 3 As shown, the top of the cabinet of the electromagnetic shielding device is provided with two lock buckles 301 arranged side by side, and one side of the cabinet is provided with a buckle 302 corresponding to each lock buckle. The side extension pipe 303 and the side air inlet 309 are respectively located on both sides of the electromagnetic shielding device, and the side extension pipe 303 and the buckle 302 are located on the same side of the electromagnetic shielding device.

[0046] See also Figure 4 , Figure 4 This is a flow chart of a method for detecting the desorption flow of a carbon canister of an automobile provided in an embodiment of the present application. Figure 4 As shown, the automobile carbon canister desorption flow detection method provided in the embodiment of the present application comprises:

[0047] Step S101, using a flow data acquisition module to collect the desorption flow rate in the carbon canister of the tested vehicle to obtain the desorption flow rate of the first carbon canister under the whole vehicle working condition.

[0048] In this step, the flow data acquisition module uses a flow meter to collect the desorption flow rate data of the carbon canister per second. The flow data acquisition module is connected to the data storage module, and the flow data acquisition module stores the collected desorption flow rate data in the data storage module.

[0049] The flow data acquisition module includes a flow meter, and the flow meter can be a vortex flow meter, for example. The use time, model and operating temperature range of the flow meter have a great influence on the measurement result of the flow meter.

[0050] In the embodiment of the present application, when performing the desorption flow rate test of the automobile carbon canister, the tested vehicle is first moved to the chassis dynamometer and bound to the chassis dynamometer. After confirming that the carbon canister stop valve, the carbon canister control valve, and the carbon canister status of the tested vehicle are all normal, the carbon canister stop valve atmospheric end connection pipe is disconnected, and the rubber hose is connected to the carbon canister stop valve atmospheric end.

[0051] Open the cabinet of the electromagnetic shielding device from the side, push the vortex flowmeter into the cabinet, close the side cabinet door, and use the lock to lock the side cabinet door and the top of the cabinet. Connect the rubber hose to the gas outlet of the vortex flowmeter through the side extension tube of the cabinet, so as to connect the carbon canister stop valve to the atmosphere end with the vortex flowmeter through the rubber hose. Then, lift the copper plate covering the visual window in the electromagnetic shielding device, and observe whether the rubber hose is tightly connected to the gas outlet of the vortex flowmeter through the visual window to ensure the air tightness of the connection. Then buckle the copper plate back to its original position to ensure that it covers the entire visual window. Then, connect the vortex flowmeter to the flow display device and the data storage module through the side air inlet through the data transmission line to store the data collected by the vortex flowmeter in the data storage module.

[0052] The electronic fuel injection parameter acquisition module is connected to an on-board diagnostic system (OBD), and the electronic fuel injection parameter acquisition module is connected to and communicates with a controller via an Ethernet interface.

[0053] Deploy the automobile carbon canister desorption flow detection system according to the above connection method, and after confirming that the flow display device shows zero, turn on the lower computer, environmental chamber and chassis dynamometer, and open the data acquisition software to check whether the electronic injection signal is normal. After confirming that the signal is normal, run the data acquisition software to start acquisition, and simultaneously turn on the data recorder to start recording data. Then, control the vehicle under test to run according to the curve of the working conditions specified by the national standard. After the vehicle under test runs according to the specified working conditions, stop the vehicle and stop data acquisition.

[0054] Among them, when the tested vehicle is running according to the working condition, the flow data acquisition module can be used to obtain the first carbon canister desorption flow of the whole vehicle under the working condition. At this time, the voltage data collected by the flow meter can be extracted, and the voltage data can be converted into the carbon canister desorption flow rate according to the preset conversion relationship, wherein the unit of the carbon canister desorption flow rate is L / min. From the converted carbon canister desorption flow rate, the carbon canister desorption flow rate at different times within the target time period corresponding to the regulatory working condition is extracted, and the carbon canister desorption flow rate curve is established based on the carbon canister desorption flow rate at different times, and the carbon canister desorption flow rate curve is integrated to obtain the first carbon canister desorption flow rate.

[0055] The carbon canister desorption velocity curve is a velocity curve that changes with time, and the unit of the carbon canister desorption flow rate is L. Specifically, the carbon canister desorption flow rates at different times can be fitted to establish the carbon canister desorption flow rate curve, and the abscissa of the carbon canister desorption flow rate curve is time, and the ordinate is the carbon canister desorption flow rate. Then, with time as a variable, the carbon canister desorption flow rate is integrated over time to obtain the first carbon canister desorption flow rate.

[0056] Step S102, using the EFI parameter acquisition module to obtain the carbon canister flow rate of the tested vehicle under different engine control parameters, and determining the second carbon canister desorption flow rate according to the carbon canister flow rate.

[0057] In this step, while the flow data acquisition module is used to obtain the first carbon canister desorption flow, the EFI parameter acquisition module can also be used to obtain the second carbon canister desorption flow, so as to jointly determine the final carbon canister desorption flow by using the first carbon canister desorption flow and the second carbon canister desorption flow.

[0058] Specifically, when the EFI parameter acquisition module is used to obtain the carbon canister flow rate of the tested vehicle under different engine control parameters, the EFI parameter acquisition module can be used to directly obtain the carbon canister flow rate of the engine under different solenoid valve openings. The unit of the carbon canister flow rate is kg / s, and different solenoid valve openings correspond to different loads and different speeds of the engine.

[0059] Then, the second carbon canister desorption flow rate is determined according to the carbon canister flow rate. Here, the carbon canister flow rates at different times are also fitted to obtain the carbon canister flow curve, and the carbon canister flow curve is integrated within the target time under the working condition with time as a variable to obtain the carbon canister desorption mass. Then, the carbon canister desorption mass is used to determine the second carbon canister desorption flow rate.

[0060] The carbon canister desorption mass is recorded as: m, in kg. When the carbon canister desorption mass is used to determine the second carbon canister desorption flow rate, the ratio of the carbon canister desorption mass m to the air density ρ can be determined as the second carbon canister desorption flow rate.

[0061] Step S103, using the desorption flow correction model and the second carbon canister desorption flow, the first carbon canister desorption flow is corrected to determine the final carbon canister desorption flow of the tested vehicle.

[0062] The desorption flow rate correction model may refer to a model for correcting the corresponding carbon canister desorption flow rate in the first carbon canister desorption flow rate by using the target second carbon canister desorption flow rate in the second carbon canister desorption flow rate. Exemplarily, the desorption flow rate correction model may be a linear correction model.

[0063] The target second carbon canister desorption flow rate is the second carbon canister desorption flow rate measured at low pressure and low flow rate. Exemplarily, the target second carbon canister desorption flow rate is the second carbon canister desorption flow rate measured by the flowmeter when the voltage is lower than 0.14V.

[0064] After determining the desorption flow rate of the first carbon canister and the second carbon canister desorption flow rate, a desorption flow rate correction model can be constructed based on the degree of influence of multiple precision influencing factors on the final carbon canister desorption flow rate, and the first carbon canister desorption flow rate and the second carbon canister desorption flow rate can be substituted into the desorption flow rate correction model to determine the output result of the desorption flow rate correction model as the final carbon canister desorption flow rate.

[0065] Specifically, when constructing a linear correction model, the initial correction coefficient corresponding to each precision influencing factor can be determined based on the degree of influence of each precision influencing factor on the final carbon canister desorption flow rate. For example: according to the degree of influence of each precision influencing factor on the final carbon canister desorption flow rate, the initial correction value of each precision influencing factor is determined, and the initial correction coefficient corresponding to each precision influencing factor is determined using the mean and standard deviation corresponding to all initial correction values. The initial correction coefficient can be calculated according to the following formula:

[0066]

[0067] Among them, A i represents the i-th initial correction coefficient, X i represents the initial correction value corresponding to the i-th precision influencing factor, E(x) represents the mean corresponding to all initial correction values, and D(x) represents the standard deviation corresponding to all initial correction values.

[0068] In addition, accuracy influencing factors include, but are not limited to: pressure influencing factors, temperature influencing factors, viscosity influencing factors and fluidity influencing factors.

[0069] After determining the initial correction coefficient, the final correction coefficient can be determined based on the initial correction coefficient and the weighted value corresponding to each precision influencing factor, and then the desorption flow correction model is constructed based on the final correction coefficient, the first carbon canister desorption flow rate and the second carbon canister desorption flow rate. Among them, the final correction coefficient is recorded as: A, and the weighted value corresponding to the i-th precision influencing factor is recorded as: λ i, the final correction coefficient can be determined according to the following calculation formula:

[0070]

[0071] Where n represents the number of accuracy influencing factors.

[0072] The constructed linear desorption flow correction model can be expressed as:

[0073] V = K × A + B;

[0074] Wherein, V represents the final carbon canister desorption flow rate, B represents the first carbon canister desorption flow rate of the first carbon canister that does not require correction, and K represents the target second carbon canister desorption flow rate under low pressure and low flow rate.

[0075] In this way, through the desorption flow correction model, the product of the target second carbon canister desorption flow and the final correction coefficient can be used to replace the target first carbon canister desorption flow at low pressure and low flow rate in the first carbon canister desorption flow. Then, the product and the remaining first carbon canister desorption flow except the target first carbon canister desorption flow are used as the final carbon canister desorption flow.

[0076] In another embodiment, the flow ratio corresponding to the target second carbon canister desorption flow rate and the target first carbon canister desorption flow rate under low pressure and low flow rate can also be determined. The flow ratio represents the difference between the first carbon canister desorption flow rate and the second carbon canister desorption flow rate under low pressure and low flow rate. The larger the flow ratio, the greater the difference between the first carbon canister desorption flow rate and the second carbon canister desorption flow rate. The smaller the flow ratio, the smaller the difference between the first carbon canister desorption flow rate and the second carbon canister desorption flow rate. When the flow ratio is greater than or equal to the flow ratio threshold, it means that the difference between the two carbon canister desorption flows is large, the first carbon canister desorption flow rate is relatively inaccurate, and the first carbon canister desorption flow rate needs to be significantly corrected; when the flow ratio is less than the flow ratio threshold, it means that the difference between the two carbon canister desorption flows is small, the first carbon canister desorption flow rate is relatively accurate, and only a small correction is needed to the first carbon canister desorption flow rate.

[0077] Then, different calculation methods are selected according to the flow ratio to determine the final carbon canister desorption flow rate under low pressure and low flow rate. Specifically, it can be determined whether the flow ratio meets the flow threshold condition, wherein the flow threshold condition may refer to a condition that is less than the flow ratio threshold. If the flow threshold condition is met, that is, the flow ratio is less than the flow ratio threshold, it means that the flow meter measurement result is relatively accurate. At this time, the final carbon canister desorption flow rate can be determined based on the difference between the first carbon canister desorption flow rate and the second carbon canister desorption flow rate. In this case, the first carbon canister desorption flow rate needs to be slightly corrected, for example: the product of the difference and the set flow coefficient and the sum of the first carbon canister desorption flow rate are used as the final carbon canister desorption flow rate, wherein the set flow coefficient is a number between 0 and 0.3, for example: 0.1. Those skilled in the art can determine the specific value of the set flow coefficient according to actual conditions, and this application is not limited here. On the contrary, if the flow threshold condition is not met, that is, the flow ratio is greater than or equal to the flow ratio threshold, it means that the flow meter measurement result is relatively inaccurate, and the second carbon canister desorption flow needs to be used to significantly correct the first carbon canister desorption flow. At this time, the flow correction value corresponding to the flow ratio and the working parameters corresponding to the flow meter can be selected from the pre-set correction value table, and the sum of the flow correction value and the first carbon canister desorption flow is determined as the final carbon canister desorption flow. Among them, the working parameters not only reflect the device properties of the flow meter itself, but also reflect the working environment properties, for example: the working parameters include the use time of the flow meter, the flow meter model, and the working temperature range of the flow meter.

[0078] Compared with the automobile carbon canister desorption flow detection method in the prior art, the present application can obtain the first carbon canister desorption flow and the second carbon canister desorption flow respectively, and correct part of the experimental data of the first carbon canister desorption flow through the desorption flow correction model and the second carbon canister desorption flow, and finally obtain an accurate carbon canister desorption flow, which improves the detection accuracy and stability of the carbon canister desorption flow of the measured vehicle under low pressure and low flow rate conditions, and solves the problem of low measurement accuracy of the carbon canister desorption flow by the vortex flowmeter under low pressure and low flow rate.

[0079] In addition, the present application also shields the influence of vibration and electromagnetic field on the measurement results through the electromagnetic shielding module, thereby avoiding the influence of vibration and electromagnetic field environment on the carbon canister desorption flow detection results, and further improving the detection accuracy of the carbon canister desorption flow.

[0080] Based on the same inventive concept, an automobile carbon canister desorption flow detection system corresponding to the automobile carbon canister desorption flow detection method is also provided in the embodiment of the present application. Since the principle of solving the problem by the system in the embodiment of the present application is similar to the above-mentioned automobile carbon canister desorption flow detection method in the embodiment of the present application, the implementation of the system can refer to the implementation of the method, and the repeated parts will not be repeated.

[0081] See also Figure 5 , Figure 5This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 5 As shown in , the electronic device 600 includes a processor 610 , a memory 620 and a bus 630 .

[0082] The memory 620 stores machine-readable instructions executable by the processor 610. When the electronic device 600 is running, the processor 610 communicates with the memory 620 via the bus 630. When the machine-readable instructions are executed by the processor 610, the above-mentioned Figure 4 The steps of the automobile carbon canister desorption flow detection method in the method embodiment shown in the embodiment and the specific implementation method can be referred to the method embodiment, which will not be repeated here.

[0083] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 4 The steps of the automobile carbon canister desorption flow detection method in the method embodiment shown in the embodiment and the specific implementation method can be referred to the method embodiment, which will not be repeated here.

[0084] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0085] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0086] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0087] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0088] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0089] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for detecting the desorption flow rate of a carbon canister of an automobile, characterized in that: A controller applied to a vehicle carbon canister desorption flow detection system, wherein the vehicle carbon canister desorption flow detection system further comprises an electromagnetic shielding module, a flow data acquisition module, and an EFI parameter acquisition module, wherein the flow data acquisition module comprises a flow meter, and the flow meter is arranged in the electromagnetic shielding module, and the method comprises: The flow meter is used to collect the desorption flow rate in the carbon canister of the tested vehicle to obtain the desorption flow rate of the first carbon canister under the whole vehicle working condition; Using the EFI parameter acquisition module to obtain the carbon canister flow rate of the tested vehicle under different engine control parameters, and determining the second carbon canister desorption flow rate according to the carbon canister flow rate; The first carbon canister desorption flow rate is corrected by using the desorption flow rate correction model and the second carbon canister desorption flow rate to determine a final carbon canister desorption flow rate of the tested vehicle.

2. The method according to claim 1, characterized in that The method of correcting the first carbon canister desorption flow rate by using the desorption flow rate correction model and the second carbon canister desorption flow rate includes: Based on the influence of multiple precision influencing factors on the final carbon canister desorption flow rate, constructing the desorption flow rate correction model; The first carbon canister desorption flow rate and the second carbon canister desorption flow rate are substituted into the desorption flow rate correction model to determine the output result of the desorption flow rate correction model as the final carbon canister desorption flow rate.

3. The method according to claim 2, characterized in that The desorption flow correction model is constructed based on the influence of multiple precision influencing factors on the final carbon canister desorption flow, including: Based on the influence of each precision influencing factor on the final carbon canister desorption flow rate, determine the initial correction coefficient corresponding to each precision influencing factor; Determine the final correction coefficient according to the initial correction coefficient and the weighted value corresponding to each accuracy influencing factor; A desorption flow correction model is constructed according to the final correction coefficient, the first carbon canister desorption flow rate, and the second carbon canister desorption flow rate.

4. The method according to claim 3, characterized in that Determining the initial correction coefficient corresponding to each accuracy influencing factor includes: According to the influence degree of each precision influencing factor on the final carbon canister desorption flow rate, the initial correction value of each precision influencing factor is determined; The initial correction coefficient corresponding to each accuracy influencing factor is determined by using the mean and standard deviation corresponding to all initial correction values.

5. The method according to claim 1, characterized in that The desorption flow correction model is a model that uses the target second carbon canister desorption flow in the second carbon canister desorption flow to correct the corresponding carbon canister desorption flow in the first carbon canister desorption flow, and the target second carbon canister desorption flow is the carbon canister desorption flow measured at low pressure and low flow rate.

6. The method according to claim 1, characterized in that The step of determining the desorption flow rate of the second carbon canister according to the carbon canister flow rate includes: Integrating the carbon canister flow rate over time to obtain the carbon canister desorption mass; The desorption flow rate of the second carbon canister is determined by using the carbon canister desorption mass.

7. The method according to claim 6, characterized in that The method of determining the desorption flow rate of the second carbon canister by using the desorption mass of the carbon canister includes: The desorption flow rate of the second carbon canister is determined according to the ratio of the carbon canister desorption mass to the air density.

8. The method according to claim 1, characterized in that The method of using the electronic fuel injection parameter acquisition module to obtain the carbon canister flow rate of the tested vehicle under different engine control parameters includes: The EFI parameter acquisition module is used to obtain the carbon canister flow rate of the engine at different solenoid valve openings.

9. An automobile carbon canister desorption flow detection system, characterized in that: It includes a controller, an electromagnetic shielding module, a flow data acquisition module, and an EFI parameter acquisition module. The flow data acquisition module includes a flow meter, and the flow meter is arranged in the electromagnetic shielding module; The controller is used to perform the automobile carbon canister desorption flow detection method according to any one of claims 1 to 8; The flow data acquisition module is connected to the carbon canister of the tested vehicle and is used to obtain the desorption flow of the first carbon canister under the working condition of the whole vehicle; The EFI parameter acquisition module is connected to the on-board self-diagnosis system of the tested vehicle and is used to obtain the carbon canister flow rate of the tested vehicle under different engine control parameters; The electromagnetic shielding module is used to eliminate the influence of vibration and electromagnetic field on the collection results of the flow meter.

10. An electronic device, characterized in that: include: A processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the storage medium via the bus, and the processor executes the machine-readable instructions to perform the steps of the automobile carbon canister desorption flow detection method as described in any one of claims 1 to 8.

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