Fuel evaporative emission control system fault diagnosis method and related device

Abstract

The invention discloses a fuel evaporative emission control system fault diagnosis method and a related device, which are used in the field of vehicle fuel equipment control, and the method comprises the steps: firstly, determining a sampling frequency according to a preset sampling rule; then, motor voltage is collected based on the sampling frequency, and a plurality of voltage collection values are obtained; then, based on the plurality of voltage acquisition values, calculating the current and the current frequency of the motor; and finally, according to the current and the current frequency, determining the fault state of the fuel evaporative emission control system. Therefore, the current frequency obtained by calculating the voltage acquisition value is used as the actual operation frequency of the motor, the current of the motor and the actual operation frequency of the motor are comprehensively considered, the fault state of the fuel evaporative emission control system is jointly determined, and the fault state of the fuel evaporative emission control system with high robustness can be obtained at low cost. And misjudgment on the fault state of the fuel evaporation emission control system is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle fuel equipment control, and in particular to a fuel evaporative emission control system fault diagnosis method and related devices. Background Art

[0002] As vehicle emission standards become increasingly stringent, in order to reduce the impact of fuel leakage on vehicle pollutant emissions, how to diagnose whether the vehicle's fuel evaporative emission control system has fuel leakage and other faults has become increasingly concerned.

[0003] At present, the fuel emission leakage diagnosis system DMTL is usually used. The relationship between motor load and motor current is used to estimate the motor load by monitoring the size and change of motor current, and then the sealing of the fuel evaporative emission control system is judged according to the motor load, and whether there is fuel leakage and other faults in the fuel evaporative emission control system is diagnosed. However, the motor load is not strictly proportional to the motor current. Especially for small leakage faults with a diameter of less than 0.5 mm, it is greatly affected by factors such as sampling period, sampling resistance accuracy, and current value that is too small. The method of estimating the motor load by monitoring the size and change of motor current has poor robustness and has a high risk of misjudgment of faults such as fuel leakage. Although the introduction of motor frequency in the process of calculating motor load can improve the robustness of the motor load estimation result, the measurement of motor frequency requires the installation of equipment such as rotary encoders or photoelectric encoders, which greatly increases the diagnostic cost of fuel evaporative emission control system faults.

[0004] Therefore, how to provide a low-cost and highly robust fuel evaporative emission control system fault diagnosis method has become a problem that needs to be solved. Summary of the invention

[0005] Based on the above problems, the present application provides a fuel evaporative emission control system fault diagnosis method and related devices, which can perform fuel evaporative emission control system fault diagnosis at low cost and high robustness.

[0006] The embodiments of the present application disclose the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a fuel evaporative emission control system fault diagnosis method, which is applied to a fuel emission leakage diagnosis system DMTL, and the method includes:

[0008] Determine the sampling frequency according to the preset sampling rules;

[0009] Sampling the motor voltage based on the sampling frequency to obtain a plurality of voltage sampling values;

[0010] Calculating the current and current frequency of the motor based on the plurality of voltage acquisition values;

[0011] The fault state of the fuel evaporative emission control system is determined according to the current and the current frequency; the fault state at least includes no fault and fuel leakage.

[0012] Optionally, the calculating the current frequency of the motor based on the multiple voltage acquisition values ​​includes:

[0013] Based on the multiple voltage acquisition values, multiple characteristic voltage values ​​are determined; the difference between the characteristic voltage value and the theoretically predicted voltage wave peak value is within a preset voltage range, and the difference between the characteristic voltage value and the voltage acquisition value at a previous moment is smaller than the difference between the characteristic voltage value and the voltage acquisition value at a later moment;

[0014] According to the collection time of the plurality of characteristic voltage values, the collection time interval between two characteristic voltage values ​​adjacent to each other is calculated to obtain the current frequency of the motor.

[0015] Optionally, the step of calculating the interval between two characteristic voltage values ​​having adjacent collection times according to the collection times of the plurality of characteristic voltage values ​​to obtain the current frequency of the motor includes:

[0016] Determine multiple groups of characteristic voltage values ​​according to the collection times of the multiple characteristic voltage values; each group of characteristic voltage values ​​includes two characteristic voltage values ​​at adjacent collection times;

[0017] Calculate the collection time interval between two characteristic voltage values ​​in each group of characteristic voltage values ​​to obtain a plurality of first frequencies;

[0018] The multiple first frequencies are filtered to obtain the current frequency of the motor.

[0019] Optionally, determining the sampling frequency according to a preset sampling rule includes:

[0020] If there is no historical current frequency, the sampling frequency is determined based on the rated frequency of the motor; the historical current frequency is the current frequency calculated based on the voltage acquisition value before the current moment;

[0021] If there is a historical current frequency, the sampling frequency is determined based on the historical current frequency closest to the current moment.

[0022] Optionally, determining the fault state of the fuel evaporative emission control system according to the current and the current frequency includes:

[0023] Calculating the motor load according to the current and the current frequency;

[0024] Based on the motor load, a fault state of the evaporative emission control system is determined.

[0025] In a second aspect, an embodiment of the present application provides a fuel evaporative emission control system fault diagnosis device, which is applied to a fuel emission leakage diagnosis system DMTL, and the device includes: a determination module, a sampling module, a calculation module and a diagnosis module;

[0026] The determination module is used to determine the sampling frequency according to a preset sampling rule;

[0027] The sampling module is used to collect the motor voltage based on the sampling frequency to obtain multiple voltage collection values;

[0028] The calculation module is used to calculate the current and current frequency of the motor based on the multiple voltage acquisition values;

[0029] The diagnostic module is used to determine the fault state of the fuel evaporative emission control system according to the current and the current frequency; the fault state at least includes no fault and fuel leakage.

[0030] Optionally, the calculation module includes: a characteristic value determination unit and a calculation unit;

[0031] The characteristic value determination unit is used to determine a plurality of characteristic voltage values ​​based on the plurality of voltage acquisition values; the difference between the characteristic voltage value and the theoretically predicted voltage wave peak value is within a preset voltage range, and the difference between the characteristic voltage value and the voltage acquisition value at a previous moment is less than the difference between the characteristic voltage value and the voltage acquisition value at a subsequent moment;

[0032] The calculation unit is used to calculate the collection time interval between two adjacent characteristic voltage values ​​according to the collection time of the plurality of characteristic voltage values, so as to obtain the current frequency of the motor.

[0033] Optionally, the determining module is specifically configured to:

[0034] If there is no historical current frequency, the sampling frequency is determined based on the rated frequency of the motor; the historical current frequency is the current frequency calculated based on the voltage acquisition value before the current moment;

[0035] If there is a historical current frequency, the sampling frequency is determined based on the historical current frequency closest to the current moment.

[0036] In a third aspect, an embodiment of the present application provides a fuel evaporative emission control system fault diagnosis device, the device comprising: a memory and a processor;

[0037] The memory is used to store program code and transmit the program code to the processor;

[0038] The processor is used to execute the steps of the fuel evaporative emission control system fault diagnosis method described in any one of the first aspects according to the program code.

[0039] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which a computer program is stored. When the computer program runs on a fuel evaporative emission control system fault diagnosis device, the fuel evaporative emission control system fault diagnosis device performs the steps of the fuel evaporative emission control system fault diagnosis method described in any one of the first aspects above.

[0040] Compared with the prior art, this application has the following beneficial effects:

[0041] The embodiment of the present application provides a method for diagnosing a fault of a fuel evaporative emission control system, in which, first, a sampling frequency is determined according to a preset sampling rule; then, the motor voltage is collected based on the sampling frequency to obtain a plurality of voltage collection values; then, the motor current and current frequency are calculated based on the plurality of voltage collection values; finally, the fault state of the fuel evaporative emission control system is determined according to the current and current frequency. Thus, the current frequency obtained by calculating the voltage collection value is used as the actual operating frequency of the motor, and the fault state of the fuel evaporative emission control system is determined by comprehensively considering the motor current and the actual operating frequency of the motor, so that the fault state of the fuel evaporative emission control system with high robustness can be obtained at a low cost, and the misjudgment of the fault state of the fuel evaporative emission control system can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0043] Figure 1 A flow chart of a method for diagnosing a fuel evaporative emission control system fault provided in an embodiment of the present application;

[0044] Figure 2 A flow chart of another method for diagnosing a fault in a fuel evaporative emission control system provided in an embodiment of the present application;

[0045] Figure 3 A schematic diagram of a fuel evaporative emission control system fault diagnosis device provided in an embodiment of the present application;

[0046] Figure 4 A structural diagram of a fuel evaporative emission control system fault diagnosis device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] As mentioned above, due to the requirements of the National VI emission standards, in order to reduce the impact of fuel leakage on vehicle pollutant emissions, many vehicles have added a functional component to identify the leakage of the fuel evaporative emission control system EVAP, which consists of the fuel tank, fuel vapor pipeline to the carbon canister solenoid valve: the fuel emission leakage diagnostic module DMTL. DMTL can identify leaks with a minimum diameter of 0.5mm and can alert system faults by lighting the engine fault light.

[0048] DMTL can use the relationship between motor load and motor current to estimate motor load by monitoring the size and change of motor current, and then judge the sealing of fuel evaporative emission control system according to motor load, and diagnose whether there is fuel leakage and other faults in fuel evaporative emission control system. However, motor load is not strictly proportional to motor current, especially for small leakage faults with a diameter of less than 0.5 mm, which are greatly affected by factors such as sampling period, sampling resistance accuracy, and current value that is too small. The method of estimating motor load only by monitoring the size and change of motor current has poor robustness and has a high risk of misjudgment of faults such as fuel leakage.

[0049] In view of this, the present application provides a fuel evaporative emission control system fault diagnosis method and related devices, which are applied to the fuel emission leakage diagnosis system DMTL. In this method, the voltage acquisition value is calculated to obtain the current frequency as the actual operating frequency of the motor, and the motor current and the actual operating frequency of the motor are comprehensively considered to jointly determine the fault state of the fuel evaporative emission control system. The fault state of the fuel evaporative emission control system with high robustness can be obtained at a low cost, thereby reducing the misjudgment of the fault state of the fuel evaporative emission control system.

[0050] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution 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 part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0051] See also Figure 1 , which is a flow chart of a fuel evaporative emission control system fault diagnosis method provided by an embodiment of the present application, which is applied to a fuel emission leakage diagnosis system DMTL, and the method includes:

[0052] S101: Determine a sampling frequency according to a preset sampling rule.

[0053] Limited by the Nyquist-Shannon Sampling Theorem, the sampling frequency needs to be at least twice the highest frequency in the signal to reduce signal distortion caused by aliasing so that the sampled digital signal can fully retain the information in the original signal.

[0054] For example, since under ideal conditions, the current frequency of the motor is equal to the actual operating frequency of the motor, that is, the mechanical movement frequency of the motor, and the voltage frequency is equal to the current frequency, in order to make the sampling frequency meet the requirements of the sampling theorem, sampling rules such as the sampling frequency being five times the rated frequency of the motor can be pre-set to ensure that the sampling frequency can be much greater than the current operating frequency of the motor.

[0055] S102: Collecting the motor voltage based on the sampling frequency to obtain a plurality of voltage collection values.

[0056] For example, the determined sampling frequency is 5 kHz. Since the sampling period is the inverse of the sampling frequency, that is, the sampling period 1 / 5000=0.0002 seconds, the motor voltage is sampled every 0.0002 seconds, and multiple voltage sampling values ​​can be obtained after multiple sampling periods.

[0057] S103: Calculate the current and current frequency of the motor based on the multiple voltage acquisition values.

[0058] Exemplarily, the current of the motor can be calculated by, for example, using Ohm's law. Specifically, the resistance value of the motor can be determined by referring to the motor specification, referring to the data sheet provided by the motor manufacturer, or using a multimeter to measure the resistance of the motor winding, and then using Ohm's law, the current of the motor can be calculated through the voltage acquisition value and the resistance value of the motor.

[0059] Exemplarily, at least two characteristic voltage values ​​having voltage peaks between them and the voltage collected value at the previous moment can be found from multiple voltage collection values, and the collection time interval between the two characteristic voltage values ​​can be calculated to obtain the current frequency of the motor.

[0060] S104: Determine a fault state of the fuel evaporative emission control system according to the current and the current frequency.

[0061] Specifically, on the one hand, when the motor load increases, the resistance torque increases, causing the speed to decrease, the speed difference between the motor rotor and the rotating magnetic field becomes larger, and the motor current will also increase; on the other hand, the actual frequency of the motor will also change dynamically with the change of the motor load. In the embodiment of the present application, the calculated current frequency of the motor is used as the actual frequency of the motor to participate in the calculation of the motor load. There is no need to install a rotary encoder or a photoelectric encoder or other equipment to collect the actual frequency of the motor. The motor current and the actual frequency of the motor can be considered simultaneously in the process of calculating the motor load, and a more robust motor load can be obtained at a low cost.

[0062] As an example, the fault state of the fuel evaporative emission control system may include but is not limited to no fault, fuel leakage, and fuel blockage. In the fuel emission leakage diagnosis system DMTL, the magnitude of the motor load can reflect the tightness of the fuel, that is, the magnitude of the motor load can reflect whether there is a fuel leakage fault in the fuel evaporative emission control system. Therefore, the motor load can be calculated based on the relationship between the current and the motor load and the relationship between the current frequency and the motor load to determine the fault state of the fuel evaporative emission control system.

[0063] In the embodiment of the present application, first, the sampling frequency is determined according to the preset sampling rules; then, the motor voltage is collected based on the sampling frequency to obtain multiple voltage collection values; then, the motor current and current frequency are calculated based on the multiple voltage collection values; finally, the fault state of the fuel evaporative emission control system is determined according to the current and current frequency. Thus, the current frequency obtained by calculating the voltage collection value is used as the actual operating frequency of the motor, and the fault state of the fuel evaporative emission control system is determined by comprehensively considering the motor current and the actual operating frequency of the motor, so that the fault state of the fuel evaporative emission control system with high robustness can be obtained at a low cost, reducing the misjudgment of the fault state of the fuel evaporative emission control system.

[0064] See also Figure 2 , which is a flow chart of another method for diagnosing a fault in a fuel evaporative emission control system provided in an embodiment of the present application, the method comprising:

[0065] S201: Determine a sampling frequency according to a preset sampling rule.

[0066] Optionally, if there is no historical current frequency, the sampling frequency can be determined based on the rated frequency of the motor; if there is a historical current frequency, the sampling frequency can be determined based on the historical current frequency closest to the current moment. The historical current frequency is the current frequency calculated based on the voltage acquisition value before the current moment.

[0067] Since the current frequency will change dynamically with the change of motor load, the sampling frequency can be dynamically changed according to the current frequency to improve the sampling accuracy of the current cycle and avoid the waste of resources and large amount of calculation caused by too high sampling frequency. Since the current frequency cannot be calculated before the motor voltage is collected, in order to make the sampling frequency meet the requirements of the sampling theorem, the sampling frequency can be determined based on the rated frequency of the motor, for example, five times the rated frequency of the motor is used as the sampling frequency; after the motor voltage is collected and the current frequency is calculated, the sampling frequency can be determined based on the historical current frequency closest to the current moment, for example, five times the historical current frequency closest to the current moment is used as the sampling frequency.

[0068] S202: Collecting the motor voltage based on the sampling frequency to obtain a plurality of voltage collection values.

[0069] Specifically, the reciprocal of the sampling frequency is the sampling period, and the motor voltage is collected once in each sampling period, and multiple voltage collection values ​​are obtained after multiple sampling periods. Optionally, a minimum number of voltage collection values ​​can be pre-set, and step S203 is executed after the collected voltage collection values ​​exceed the minimum number.

[0070] S203: Determine a plurality of characteristic voltage values ​​based on the plurality of voltage acquisition values.

[0071] Specifically, the difference between the characteristic voltage value and the theoretically predicted voltage peak value is within a preset voltage range, and the characteristic voltage value Y n Compared with the voltage acquisition value Y at the previous moment n-1 The difference is less than the characteristic voltage value Y n And the voltage acquisition value Y at the next moment n+1 The preset range can be dynamically adjusted based on conditions such as sampling frequency. Thus, it can be ensured that there is a peak between the characteristic voltage value and the voltage acquisition value at the previous moment, and the characteristic voltage value is not an abnormal value with a large voltage value caused by, for example, sampling abnormality.

[0072] S204: Calculate the interval between two characteristic voltage values ​​with adjacent collection times according to the collection times of the plurality of characteristic voltage values, and obtain the current frequency of the motor.

[0073] In the embodiment of the present application, since there is a peak between the characteristic voltage value and the voltage collection value at the previous moment, and the sampling period of the motor voltage is much smaller than the voltage period, the two characteristic voltage values ​​adjacent to each other at the collection time belong to two consecutive voltage periods, and the characteristic voltage values ​​are both in the first 1 / 2 position of the voltage change process from the peak to the trough within the period. In addition, since the voltage frequency is equal to the current frequency, the current frequency of the motor can be approximately obtained by calculating the collection time interval of the two characteristic voltage values ​​adjacent to each other at the collection time.

[0074] Optionally, in order to obtain the current frequency of the motor more accurately, the current frequency of the motor may be calculated through the following steps S01 to S03:

[0075] S01: Determine multiple groups of characteristic voltage values ​​according to the collection moments of multiple characteristic voltage values.

[0076] Specifically, the determined more than two characteristic voltage values ​​may be sorted according to the order of the acquisition moments, and then the characteristic voltage values ​​adjacent to two acquisition moments may be determined as a group of characteristic voltage values ​​to obtain multiple groups of characteristic voltage values.

[0077] S02: Calculate the collection time interval between two characteristic voltage values ​​in each group of characteristic voltage values ​​to obtain a plurality of first frequencies.

[0078] Specifically, by respectively calculating the collection time intervals corresponding to each group of characteristic voltage values, a plurality of current frequencies, namely, the first frequency, can be obtained.

[0079] S03: Filter the multiple first frequencies to obtain the current frequency of the motor.

[0080] When the motor is in a non-steady state or is disturbed, the current frequency of the motor may deviate from the actual operating frequency of the motor. Optionally, filtering can be performed by, for example, taking an average value of multiple first frequencies to reduce the difference between the current frequency of the motor and the actual operating frequency of the motor, so that the obtained current frequency is closer to the actual operating frequency of the motor, so as to perform step S206.

[0081] S205: Calculate the current of the motor based on the multiple voltage acquisition values.

[0082] Exemplarily, the current of the motor may be calculated by, for example, using Ohm's law.

[0083] It is understandable that the embodiment of the present application does not limit the execution order of steps S203 to S204 and step S205. Step S205 may be executed first, and then steps S203 to S204; steps S203 to S204 and step S205 may also be executed simultaneously.

[0084] S206: Calculate the motor load according to the current and the current frequency.

[0085] Optionally, taking into account both the motor current and the current frequency, the following formula may be pre-entered to calculate the motor load:

[0086] P=(I a / I e )×f e ×f a ×T;

[0087] Among them, I a is the motor current calculated in step S103; I e is the rated current of the motor; f a is the actual frequency of the motor. In the embodiment of the present application, the current frequency of the motor calculated in step S103 is used as the actual frequency of the motor; e is the rated frequency of the motor.

[0088] S207: Determine a fault state of the fuel evaporative emission control system based on the motor load.

[0089] Specifically, the fault state of the fuel evaporative emission control system may include but is not limited to no fault, fuel leakage, and fuel blockage, etc. Optionally, the association between the motor load and the fault state of the fuel evaporative emission control system may be preset. For example, after the motor is turned on for a preset time, the following judgment may be performed to determine the fault state of the fuel evaporative emission control system: when the motor load exceeds a first threshold, it is determined that there is fuel blockage in the fuel evaporative emission control system; when the motor load is lower than a second threshold, it is determined that there is fuel leakage in the fuel evaporative emission control system; when the motor load is between the first threshold and the second threshold, it is determined that there is no fault in the fuel evaporative emission control system; wherein the first threshold is greater than the second threshold.

[0090] See also Figure 3 , which is a schematic diagram of a fuel evaporative emission control system fault diagnosis device provided in an embodiment of the present application, and the device is applied to a fuel emission leakage diagnosis system DMTL, including: a determination module 301, a sampling module 302, a calculation module 303 and a diagnosis module 304.

[0091] The determination module 301 is used to determine the sampling frequency according to a preset sampling rule;

[0092] The sampling module 302 is used to collect the motor voltage based on the sampling frequency to obtain multiple voltage collection values;

[0093] A calculation module 303 is used to calculate the current and current frequency of the motor based on multiple voltage acquisition values;

[0094] The diagnosis module 304 is used to determine the fault state of the fuel evaporative emission control system according to the current and the current frequency; the fault state at least includes no fault and fuel leakage.

[0095] Therefore, in the embodiment of the present application, the voltage acquisition value is calculated to obtain the current frequency as the actual operating frequency of the motor, and the current of the motor and the actual operating frequency of the motor are comprehensively considered to jointly determine the fault state of the fuel evaporative emission control system. The fault state of the fuel evaporative emission control system with higher robustness can be obtained at a low cost, thereby reducing the misjudgment of the fault state of the fuel evaporative emission control system.

[0096] Optionally, in some other fuel evaporation emission control system fault diagnosis devices provided in the present application, the determination module 301 is specifically used to: if there is no historical current frequency, determine the sampling frequency based on the rated frequency of the motor; the historical current frequency is the current frequency calculated based on the voltage acquisition value before the current moment; if there is a historical current frequency, determine the sampling frequency based on the historical current frequency closest to the current moment.

[0097] Optionally, in some other fuel evaporation emission control system fault diagnosis devices provided in the present application, the calculation module 303 includes: a characteristic value determination unit and a calculation unit; the characteristic value determination unit is used to determine multiple characteristic voltage values ​​based on multiple voltage collection values; the difference between the characteristic voltage value and the theoretically predicted voltage peak value is within a preset voltage range, and the difference between the characteristic voltage value and the voltage collection value at a previous moment is less than the difference between the characteristic voltage value and the voltage collection value at a later moment; the calculation unit is used to calculate the collection time interval between two adjacent characteristic voltage values ​​at the collection time according to the collection time of multiple characteristic voltage values, so as to obtain the current frequency of the motor.

[0098] Optionally, in some other fuel evaporative emission control system fault diagnosis devices provided in the present application, the calculation unit is specifically used to: determine multiple groups of characteristic voltage values ​​based on the collection time of multiple characteristic voltage values; each group of characteristic voltage values ​​includes two characteristic voltage values ​​adjacent to each other at the collection time; calculate the collection time interval between two characteristic voltage values ​​in each group of characteristic voltage values ​​to obtain multiple first frequencies; filter the multiple first frequencies to obtain the current frequency of the motor.

[0099] Optionally, in some other fuel evaporative emission control system fault diagnosis devices provided in the present application, the diagnosis module 304 is specifically used to: calculate the motor load according to the current and the current frequency; and determine the fault state of the fuel evaporative emission control system based on the motor load.

[0100] See also Figure 4 , this figure is a structural diagram of a fuel evaporative emission control system fault diagnosis device provided in an embodiment of the present application, and the device includes: a memory 401 and a processor 402.

[0101] Memory 401: used to store program codes and transmit the program codes to the processor.

[0102] Processor 402: used to execute the steps of the above-mentioned fuel evaporative emission control system fault diagnosis method according to the instructions in the program code.

[0103] In addition, the present application also provides a computer-readable storage medium, which stores computer instructions. When the computer instructions are executed on a fuel evaporative emission control system fault diagnosis device, the fuel evaporative emission control system fault diagnosis device performs the steps of the above-mentioned fuel evaporative emission control system fault diagnosis method.

[0104] The fuel evaporative emission control system fault diagnosis method and related devices provided in the present application can be used in the field of vehicle fuel equipment control. The above is only an example and does not limit the application field of the fuel evaporative emission control system fault diagnosis method and related devices provided by the present invention.

[0105] The terms "first", "second", "third" and "fourth" etc. in the specification, claims and drawings of this application are used to distinguish different objects rather than to limit a specific order.

[0106] In the embodiments of the present application, the words "as an example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "as an example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the words "as an example" or "for example" is intended to present the relevant concepts in a specific way.

[0107] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0108] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments. The device and storage medium embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components indicated as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. A person of ordinary skill in the art can understand and implement it without creative work.

[0109] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for diagnosing faults in a fuel evaporative emission control system, characterized in that: Applied to a fuel emission leakage diagnosis system DMTL, the method comprises: Determine the sampling frequency according to the preset sampling rules; Sampling the motor voltage based on the sampling frequency to obtain a plurality of voltage sampling values; Calculating the current and current frequency of the motor based on the plurality of voltage acquisition values; The fault state of the fuel evaporative emission control system is determined according to the current and the current frequency; the fault state at least includes no fault and fuel leakage.

2. The method according to claim 1, characterized in that The step of calculating the current frequency of the motor based on the plurality of voltage acquisition values ​​comprises: Based on the multiple voltage acquisition values, multiple characteristic voltage values ​​are determined; the difference between the characteristic voltage value and the theoretically predicted voltage wave peak value is within a preset voltage range, and the difference between the characteristic voltage value and the voltage acquisition value at a previous moment is smaller than the difference between the characteristic voltage value and the voltage acquisition value at a later moment; According to the collection time of the plurality of characteristic voltage values, the collection time interval between two characteristic voltage values ​​adjacent to each other is calculated to obtain the current frequency of the motor.

3. The method according to claim 2, characterized in that The step of calculating the interval between two characteristic voltage values ​​having adjacent collection times according to the collection times of the plurality of characteristic voltage values ​​to obtain the current frequency of the motor includes: Determine multiple groups of characteristic voltage values ​​according to the collection times of the multiple characteristic voltage values; each group of characteristic voltage values ​​includes two characteristic voltage values ​​at adjacent collection times; Calculate the collection time interval between two characteristic voltage values ​​in each group of characteristic voltage values ​​to obtain a plurality of first frequencies; The multiple first frequencies are filtered to obtain the current frequency of the motor.

4. The method according to claim 1, characterized in that: Determining the sampling frequency according to a preset sampling rule includes: If there is no historical current frequency, the sampling frequency is determined based on the rated frequency of the motor; the historical current frequency is the current frequency calculated based on the voltage acquisition value before the current moment; If there is a historical current frequency, the sampling frequency is determined based on the historical current frequency closest to the current moment.

5. The method according to claim 1, characterized in that The determining of the fault state of the fuel evaporative emission control system according to the current and the current frequency includes: Calculating the motor load according to the current and the current frequency; Based on the motor load, a fault state of the evaporative emission control system is determined.

6. A fuel evaporative emission control system fault diagnosis device, characterized in that: Applied to a fuel emission leakage diagnosis system DMTL, the device comprises: a determination module, a sampling module, a calculation module and a diagnosis module; The determination module is used to determine the sampling frequency according to a preset sampling rule; The sampling module is used to collect the motor voltage based on the sampling frequency to obtain multiple voltage collection values; The calculation module is used to calculate the current and current frequency of the motor based on the multiple voltage acquisition values; The diagnostic module is used to determine the fault state of the fuel evaporative emission control system according to the current and the current frequency; the fault state at least includes no fault and fuel leakage.

7. The device according to claim 6, characterized in that The calculation module includes: a characteristic value determination unit and a calculation unit; The characteristic value determination unit is used to determine a plurality of characteristic voltage values ​​based on the plurality of voltage acquisition values; the difference between the characteristic voltage value and the theoretically predicted voltage wave peak value is within a preset voltage range, and the difference between the characteristic voltage value and the voltage acquisition value at a previous moment is less than the difference between the characteristic voltage value and the voltage acquisition value at a subsequent moment; The calculation unit is used to calculate the collection time interval between two adjacent characteristic voltage values ​​according to the collection time of the plurality of characteristic voltage values, so as to obtain the current frequency of the motor.

8. The device according to claim 6, characterized in that The determination module is specifically used for: If there is no historical current frequency, the sampling frequency is determined based on the rated frequency of the motor; the historical current frequency is the current frequency calculated based on the voltage acquisition value before the current moment; If there is a historical current frequency, the sampling frequency is determined based on the historical current frequency closest to the current moment.

9. A fuel evaporative emission control system fault diagnosis device, characterized in that: The device comprises: a memory and a processor; The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the steps of the fuel evaporative emission control system fault diagnosis method according to any one of claims 1 to 5 according to the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program. When the computer program runs on a fuel evaporative emission control system fault diagnosis device, the fuel evaporative emission control system fault diagnosis device performs the steps of a fuel evaporative emission control system fault diagnosis method as described in any one of claims 1-5.

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