Fault detection method, system, engine controller, device, medium, and product

Abstract

This application discloses a fault detection method, system, engine controller, device, medium, and product, relating to the field of vehicle technology. The method includes: in response to receiving a fault detection command, acquiring first intake information of the vehicle's engine in a first state; acquiring second intake information of the engine in a second state; and determining the fault detection result of the vehicle's fuel tank air supply channel based on the first and second intake information. In this application embodiment, since the first and second intake information correspond to different opening states of the canister carbon valve, the patency of the fuel tank air supply channel will produce a distinguishable difference in the intake information between the two states. Based on this difference, the fault detection result of the fuel tank air supply channel can be determined. Therefore, even without a fuel tank pressure sensor in the vehicle, it is still possible to diagnose the blockage state of the fuel tank air supply channel, improving the accuracy of fuel tank air supply channel fault detection.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a fault detection method, system, engine controller, device, medium, and product. Background Technology

[0002] In a vehicle's fuel evaporation system, fuel vapors evaporating from the fuel tank are typically adsorbed by the carbon canister. The carbon canister valve opens at the appropriate time to introduce the adsorbed fuel vapors into the engine for combustion. The carbon canister is directly connected to the fuel tank, and the negative pressure in the engine's intake manifold draws the fuel vapors out of the carbon canister. To maintain pressure balance inside and outside the fuel tank, the fuel tank needs to replenish air in a timely manner through an air supply passage.

[0003] In related technologies, a fuel tank pressure sensor is typically used to monitor changes in fuel tank pressure, thereby determining whether the fuel tank air supply passage is blocked. However, in some vehicles with lower emission standards, fuel tank pressure sensors are usually not installed due to cost control considerations, making it difficult to effectively detect blockages in the fuel tank air supply passage. Furthermore, even in vehicles equipped with fuel tank pressure sensors, the sensors themselves may malfunction, leading to reduced accuracy in fault detection.

[0004] It is evident that the accuracy of fault detection in the fuel tank air replenishment channel is currently low. Summary of the Invention

[0005] In view of this, one of the objectives of this application is to provide a fault detection method, system, engine controller, device, medium and product that can improve the accuracy of fault detection in the fuel tank air supply channel.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: In a first aspect, embodiments of this application provide a fault detection method, the method comprising: In response to receiving a fault detection command, the vehicle acquires first intake information of the engine in a first state; and acquires second intake information of the engine in a second state; wherein the opening degree of the carbon canister valve of the vehicle is different in the first state and the second state. Based on the first and second air intake information, the fault detection results of the vehicle's fuel tank air replenishment channel are determined.

[0007] In one possible implementation, the first intake information includes a first intake volume and a second intake volume, and the second intake information includes a third intake volume and a fourth intake volume. Based on the first and second air intake information, determine the fault detection results of the vehicle's fuel tank air replenishment channel, including: A first ratio of the first intake volume to the second intake volume is determined, and a second ratio of the third intake volume to the fourth intake volume is determined; wherein the first intake volume and the third intake volume are both determined based on the opening of the engine throttle valve, and the second intake volume and the fourth intake volume are both determined based on the pressure of the engine intake manifold. The fault detection result of the fuel tank air replenishment channel is determined based on the first ratio and the second ratio.

[0008] In one possible implementation, obtaining the first intake information of the vehicle's engine in the first state includes: It acquires the throttle opening, the pressure on the intake side of the throttle, and the temperature on the intake side of the throttle; and it acquires the intake manifold pressure and the engine speed. The first intake volume is determined based on the throttle opening, the pressure on the intake side of the throttle, and the temperature on the intake side of the throttle. The second intake volume is determined based on the intake manifold pressure and engine speed.

[0009] In one possible implementation, the fault detection result of the fuel tank air supply channel is determined based on a first ratio and a second ratio, including: The fault detection result of the fuel tank air replenishment channel is determined based on the target difference and the preset difference threshold; where the target difference is the absolute value of the difference between the first ratio and the second ratio.

[0010] In one possible implementation, the fault detection result of the fuel tank air supply channel is determined based on the target difference and a preset difference threshold, including: If the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

[0011] In one possible implementation, if the target difference is less than a preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked, including: Based on the ambient pressure of the vehicle's environment and the fuel level information in the vehicle's fuel tank, a preset difference threshold is determined from a preset mapping relationship that corresponds to both the ambient pressure and the fuel level information. The preset mapping relationship includes the mapping relationship between the ambient pressure, the fuel level information, and the difference threshold, respectively. In response to obtaining a preset difference threshold, if the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

[0012] In one possible implementation, if the target difference is less than a preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked, including: Based on the environmental pressure of the vehicle's environment and the fuel level information of the vehicle's fuel tank, the preset initial difference threshold is corrected to obtain the preset difference threshold; wherein, the preset initial difference threshold is the difference threshold obtained by calibration under preset environmental pressure and preset fuel level information. In response to obtaining a preset difference threshold, if the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

[0013] In one possible implementation, the fault detection result of the fuel tank air supply channel is determined based on a first ratio and a second ratio, including: The oxygen content information in the engine exhaust is obtained using the vehicle's oxygen sensor. Based on the oxygen content information, the first fuel correction amount of the engine in the first state and the second fuel correction amount of the engine in the second state are determined; wherein, the first fuel correction amount and the second fuel correction amount are both correction amounts for adjusting the fuel injection amount based on the oxygen content information, and the opening degree of the carbon canister valve in the first state is smaller than the opening degree of the carbon canister valve in the second state. Based on the first fuel correction amount and the second fuel correction amount, determine the change information of the fuel correction amount; Based on the first ratio, the second ratio, and the change information in fuel correction amount, the fault detection result of the vehicle's fuel tank air replenishment channel is determined.

[0014] In one possible implementation, the fault detection result of the vehicle's fuel tank air supply passage is determined based on a first ratio, a second ratio, and information on changes in fuel trim, including: If the first ratio, the second ratio, and the change information of fuel correction amount meet the preset conditions, the fault detection result of the vehicle's fuel tank air replenishment passage is determined to be: there is a blockage in the fuel tank air replenishment passage; The preset conditions include at least the following: The absolute value of the difference between the first ratio and the second ratio is less than a preset difference threshold; The change information of fuel trim indicates that the fuel trim is changing in the direction of reducing the amount of fuel injected by the engine, and the duration of the change in fuel trim is less than a preset duration threshold.

[0015] In one possible implementation, after determining the fault detection result of the vehicle's fuel tank air supply passage, the method further includes: In response to the fault detection result indicating that the fuel tank air supply passage of the vehicle is blocked, the desorption adjustment parameters are determined based on the ambient temperature of the vehicle's environment, the pressure of the engine's intake manifold, the engine speed, and the fuel level information of the vehicle's fuel tank. Adjust the working state of the carbon canister valve according to the desorption adjustment parameters.

[0016] In one possible implementation, the desorption adjustment parameters include at least adjusting the opening degree and adjusting the desorption duration, wherein the adjusting desorption duration is used to limit the cumulative duration for which the carbon canister valve is in the open state; Adjust the operating status of the carbon canister valve according to the desorption adjustment parameters, including: Adjust the opening of the carbon canister valve to the adjusted opening, and control the cumulative duration for which the carbon canister valve maintains the adjusted opening to be less than or equal to the adjusted desorption duration.

[0017] In one possible implementation, before acquiring the first intake information of the vehicle's engine in the first state, the method further includes: Obtain multiple engine speeds, multiple loads, and engine throttle opening within a preset statistical time period; The engine speed fluctuation value is determined based on multiple speeds, and the engine load fluctuation value is determined based on multiple loads; If the speed fluctuation value is less than the preset speed fluctuation threshold and the load fluctuation value is less than the preset load fluctuation threshold, the vehicle is determined to be in the first state.

[0018] Secondly, embodiments of this application provide a fault detection system, the system comprising: The response module is used to respond to receiving a fault detection command by acquiring the first intake information of the vehicle's engine in a first state and acquiring the second intake information of the engine in a second state, wherein the opening degree of the carbon canister valve of the vehicle is different in the first state and the second state. The determination module is used to determine the fault detection result of the vehicle's fuel tank air replenishment channel based on the first air intake information and the second air intake information.

[0019] Thirdly, embodiments of this application provide an engine controller, which includes a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, it implements the method provided in the first aspect.

[0020] Fourthly, embodiments of this application provide an electronic device, which includes an engine controller as provided in the third aspect.

[0021] Fifthly, embodiments of this application provide a computer-readable storage medium storing a computer program, which, when executed by one or more processors, implements the method provided in the first aspect.

[0022] In a sixth aspect, embodiments of this application provide a computer program product, which includes a computer program that, when executed by one or more processors, implements the method provided in the first aspect.

[0023] The fault detection method provided in this application embodiment, in response to receiving a fault detection command, acquires first intake information of the vehicle's engine in a first state; and acquires second intake information of the engine in a second state; wherein the opening degree of the carbon canister valve of the vehicle is different in the first state and the second state; and determines the fault detection result of the vehicle's fuel tank air supply channel based on the first intake information and the second intake information. In this application embodiment, since the first intake information and the second intake information correspond to different opening states of the carbon canister valve, whether the fuel tank air supply channel is unobstructed or not will produce a distinguishable difference in the intake information in the two states. Based on this difference, the fault detection result of the fuel tank air supply channel can be determined. Therefore, even when the vehicle is not equipped with a fuel tank pressure sensor or the fuel tank pressure sensor is malfunctioning and cannot be used normally, it is still possible to detect the blockage state of the fuel tank air supply channel, thereby improving the accuracy of fuel tank air supply channel fault detection. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. It should be understood that the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] The attached diagram is described below: Figure 1 A schematic diagram of the structure of a fuel evaporation system involved in a fault detection method provided in this application embodiment; Figure 2 A flowchart illustrating a fault detection method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the functional modules of a fault detection system provided in an embodiment of this application; Figure 4 This is a schematic diagram of the hardware structure of an engine controller provided in an embodiment of this application.

[0026] Explanation of reference numerals in the attached figures: 100. Fuel vaporization system; 101. Fuel tank; 102. Carbon canister; 103. Carbon canister valve; 104. Fuel tank air filler valve; 105. Air filter; 106. Throttle body; 107. Intake manifold; 300. Fault detection system; 310. Response module; 320. Determination module 401. Processor; 402. Memory; 403. Communication interface; 410. Bus. Detailed Implementation

[0027] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0029] To facilitate a better understanding of the solutions in the embodiments of this application, the relevant technologies will be introduced first below.

[0030] To prevent fuel vapors from evaporating from the fuel tank from being released into the atmosphere and causing pollution, vehicles are typically equipped with a fuel evaporation system. This system generally includes the fuel tank, carbon canister, carbon canister valve, and fuel tank air intake passage. The carbon canister is filled with adsorbent materials such as activated carbon to adsorb fuel vapors evaporating from the fuel tank. When the carbon canister valve opens at the appropriate time, the fuel vapors adsorbed in the carbon canister are drawn into the engine through the intake manifold under the negative pressure created by the engine throttle valve, where they participate in combustion. This process is called carbon canister desorption or flushing.

[0031] During the desorption process, the negative pressure in the engine intake manifold actively draws fuel vapor from the carbon canister. Since the carbon canister is connected to the fuel tank, a negative pressure also forms inside the fuel tank. To maintain pressure balance inside and outside the fuel tank, the fuel tank needs to be replenished with fresh air through the fuel tank air supply channel. If the fuel tank air supply channel is blocked, the fuel tank cannot be replenished with air in time. Under the condition of continuous carbon canister flushing, the fuel tank may remain in a negative pressure state, which can easily lead to fuel tank deformation or even damage.

[0032] In related technologies, fuel tank pressure sensors are typically used to monitor changes in fuel tank pressure, thereby determining whether the fuel tank air supply passage is blocked. However, in some countries or regions with lower emission standards, such as those implementing EU4 or EU5 emission regulations, fuel tank leak detection is not mandatory. Due to cost control considerations, vehicles in these regions are usually not equipped with fuel tank pressure sensors, making it difficult to effectively detect blockages in the fuel tank air supply passage. Furthermore, for vehicles equipped with fuel tank pressure sensors, the installation increases vehicle costs, the sensor itself requires testing, the detection logic is complex, and the accuracy of detection is also difficult to guarantee if the fuel tank pressure sensor itself malfunctions.

[0033] To address the technical problems in the background art, embodiments of this application provide a fault detection method, a fault detection system, an engine controller, electronic equipment, a computer-readable storage medium, and a computer program product. The fuel evaporation system involved in the fault detection method provided in this application embodiment will be described below. Please refer to... Figure 1 , Figure 1 This is a schematic diagram of the structure of a fuel evaporation system involved in a fault detection method provided in an embodiment of this application.

[0034] exist Figure 1 In the middle section: the fuel tank 101 is connected to the carbon canister 102 via a pipe. The carbon canister 102 is used to adsorb the fuel vapor that evaporates in the fuel tank 101. The carbon canister 102 is connected to the intake manifold 107 of the engine via a desorption pipe. A carbon canister valve 103 is installed on the desorption pipe. The carbon canister valve 103 is used to control the opening and closing of the desorption path between the carbon canister 102 and the intake manifold 107. The carbon canister 102 is also connected to the air filter 105 via a make-up air pipe. A fuel tank make-up air valve 104 is installed on the make-up air pipe. The gas path for replenishing gas to the fuel tank 101, consisting of the fuel tank 101, the carbon canister 102 and the make-up air pipe, is called the fuel tank make-up air channel.

[0035] Throttle valve 106 is located on the intake passage of the engine and upstream of intake manifold 107. Outside air enters the engine cylinders through throttle valve 106 and intake manifold 107. Manifold pressure sensor is located on intake manifold 107 to collect the pressure of intake manifold 107. Oxygen sensor is located on exhaust passage of the engine to collect oxygen content information in the exhaust. Fuel tank level sensor is located on fuel tank 101 to collect fuel tank level information. Engine controller is electrically connected to carbon canister valve 103, fuel tank replenishment valve 104, throttle valve 106, manifold pressure sensor, oxygen sensor, and fuel tank level sensor to obtain signals collected by each sensor and control the operation of each valve.

[0036] In some embodiments, the fuel evaporation system 100 may further include a temperature and pressure sensor disposed on the intake side of the throttle valve 106, a crankshaft position sensor for acquiring engine speed, an ambient pressure sensor for acquiring ambient pressure, and an ambient temperature sensor for acquiring ambient temperature. All of these sensors are electrically connected to the engine controller. It should be noted that these sensors are all existing sensors in the vehicle engine control system, and the fault detection method provided in this application embodiment can be implemented without adding any new sensors to the vehicle.

[0037] Normally, the carbon canister valve 103 is closed by default, but it opens when carbon canister desorption is required. When the carbon canister valve 103 opens, the negative pressure in the intake manifold 107 draws fuel vapor adsorbed in the carbon canister 102. Fresh air from outside enters the carbon canister 102 through the air filter 105 and the fuel tank air supply valve 104, forming a flushing airflow through the carbon canister 102. This flushing airflow carries fuel vapor through the carbon canister valve 103 into the intake manifold 107, and then into the engine cylinders for combustion. Simultaneously, the supplemented fresh air maintains the pressure balance inside and outside the fuel tank 101.

[0038] If the fuel tank air supply channel becomes blocked, such as if the fuel tank air supply valve 104 or the air supply pipe is blocked, outside air cannot enter the carbon canister 102 and the fuel tank 101 through the fuel tank air supply channel. Under the condition that the carbon canister valve 103 is continuously open for desorption, the fuel tank 101 will be in a negative pressure state, which can easily lead to deformation or even damage to the fuel tank 101.

[0039] Please see Figure 2 , Figure 2 This is a flowchart illustrating a fault detection method provided in an embodiment of this application. This fault detection method can be applied to, for example... Figure 1 The fuel evaporation system 100 shown in the figure has the following fault detection method, which specifically includes the following steps 210 to 220.

[0040] Step 210: In response to receiving a fault detection command, the vehicle obtains first intake information of the engine in the first state; and obtains second intake information of the engine in the second state; wherein the opening degree of the carbon canister valve of the vehicle is different in the first state and the second state.

[0041] Step 220: Determine the fault detection result of the vehicle's fuel tank air replenishment channel based on the first air intake information and the second air intake information.

[0042] The fault detection method provided in this application embodiment, in response to receiving a fault detection command, acquires first intake information of the vehicle's engine in a first state; and acquires second intake information of the engine in a second state; wherein the opening degree of the carbon canister valve of the vehicle is different in the first state and the second state; and determines the fault detection result of the vehicle's fuel tank air supply channel based on the first intake information and the second intake information. In this application embodiment, since the first intake information and the second intake information correspond to different opening states of the carbon canister valve, whether the fuel tank air supply channel is unobstructed or not will produce a distinguishable difference in the intake information in the two states. Based on this difference, the fault detection result of the fuel tank air supply channel can be determined. Therefore, even when the vehicle is not equipped with a fuel tank pressure sensor or the fuel tank pressure sensor is malfunctioning and cannot be used normally, it is still possible to diagnose the blockage state of the fuel tank air supply channel, thereby improving the accuracy of fuel tank air supply channel fault detection.

[0043] The fault detection method provided in this application can be executed by the engine controller, by other on-board controllers that are communicatively connected to the engine controller, or by external diagnostic equipment in conjunction with the engine controller. For simplicity and consistency, the following method embodiments are all described using the engine controller as an example.

[0044] The vehicles involved in this application embodiment can be private cars, such as sedans, SUVs, MPVs, or pickup trucks. Vehicles can also be commercial vehicles, such as vans, buses, small trucks, or large semi-trailers. Vehicles can be gasoline-powered or new energy vehicles. When a vehicle is a new energy vehicle, it can be a hybrid vehicle or a pure electric vehicle.

[0045] In step 210, the fault detection command is a command used to trigger fault detection of the fuel tank air supply passage. In some embodiments, the fault detection command may be sent by an external diagnostic tool. For example, in a vehicle maintenance scenario, the maintenance personnel connect the diagnostic tool to the vehicle's on-board diagnostic interface and send the fault detection command to the engine controller through the diagnostic tool. In other embodiments, the fault detection command may also be automatically generated by the engine controller according to preset triggering conditions. For example, the preset triggering conditions may include the vehicle's cumulative mileage reaching a preset mileage, the vehicle's running time after startup reaching a preset running time, or the vehicle being in a suitable driving condition for detection. When the engine controller detects that the preset triggering conditions are met, it automatically generates the fault detection command and executes subsequent detection steps without manual intervention, which can improve the timeliness and completion rate of the detection.

[0046] The first and second states described above represent two different operating states of the engine, and the opening degree of the canister carbon valve differs between the two states. It can be understood that the main difference between the first and second states lies in the opening degree of the canister carbon valve, while other engine operating parameters, such as engine speed, load, and throttle opening, remain essentially the same in both states. This ensures that the difference in intake information between the two states can be attributed to the change in the canister carbon valve opening.

[0047] For example, in the first state, the opening degree of the carbon canister valve can be zero, that is, the carbon canister valve is in the closed state. In the second state, the opening degree of the carbon canister valve can be the maximum opening degree, that is, the carbon canister valve is in the fully open state. In the first state, the carbon canister valve is closed, and the first intake air information obtained is the reference intake air information without desorption airflow interference. In the second state, the carbon canister valve is fully open. If the fuel tank air supply channel is unobstructed, the flow rate of the introduced desorption airflow is the largest. The difference in intake air information between the two states is the most obvious, and the detection discrimination is the highest.

[0048] In some embodiments, the second state can be controlled by the engine controller. Specifically, after acquiring the first intake information in the first state, the engine controller actively controls the carbon canister valve to adjust its opening from the opening in the first state to the opening in the second state, for example, from the closed state to the fully open state, and acquires the second intake information after the opening of the carbon canister valve stabilizes.

[0049] In other embodiments, the second state can also be obtained using the carbon canister valve opening that naturally occurs during the vehicle's normal desorption process. Since the vehicle itself has a carbon canister desorption requirement during operation, the engine controller can obtain the second intake information during the opening of the carbon canister valve due to this normal desorption requirement, without requiring additional intervention in the carbon canister valve's operation, thus having minimal impact on normal vehicle operation.

[0050] In some embodiments, both the first intake information and the second intake information are information used to characterize the intake state of the engine. The intake information may include one or more parameters such as engine intake volume, intake pressure, and intake temperature; this embodiment does not limit this. The intake information can be obtained through internal signals of the engine controller. Exemplarily, the internal signals obtainable by the engine controller include: throttle opening, intake volume calculated based on the throttle opening, intake volume calculated based on the intake manifold pressure sensor, carbon canister valve opening, ambient temperature, fuel tank level signal, intake manifold pressure signal, ambient pressure, engine speed, and load. These signals are all existing signals in the engine control system; the engine controller can directly read them from its own control program without adding any hardware, thus reducing the implementation cost of the detection scheme.

[0051] It should be noted that this embodiment does not limit the order of obtaining the first intake information and the second intake information. The first intake information can be obtained first and then the second intake information can be obtained, or the second intake information can be obtained first and then the first intake information can be obtained. It is only necessary to ensure that the two acquisitions correspond to different opening degrees of the carbon canister valve.

[0052] In step 220, the fault detection result of the fuel tank air supply passage is used to indicate whether there is a blockage in the fuel tank air supply passage. The fault detection result can include two possibilities: the fuel tank air supply passage is blocked, or the fuel tank air supply passage is not blocked. As described in the previous technical introduction, the convergence point of the carbon canister desorption airflow is located in the intake manifold downstream of the throttle valve. When the fuel tank air supply passage is unobstructed, changes in the carbon canister valve opening will introduce additional airflow bypassing the throttle valve, causing a corresponding change in the engine's intake air information. When the fuel tank air supply passage is blocked, changes in the carbon canister valve opening cannot introduce the aforementioned additional airflow, and the engine's intake air information remains essentially unchanged. Therefore, by comparing the first intake air information and the second intake air information, it can be determined whether there is a blockage in the fuel tank air supply passage.

[0053] In some embodiments, after determining the fault detection result, the engine controller can store the fault detection result in its own memory for maintenance personnel to read through a diagnostic tool; it can also perform corresponding protective measures and prompt operations if the fault detection result indicates that there is a blockage in the fuel tank air supply passage.

[0054] In one possible implementation, the first intake information includes a first intake volume and a second intake volume, and the second intake information includes a third intake volume and a fourth intake volume. Based on the first and second air intake information, determine the fault detection results of the vehicle's fuel tank air replenishment channel, including: A first ratio of the first intake volume to the second intake volume is determined, and a second ratio of the third intake volume to the fourth intake volume is determined; wherein the first intake volume and the third intake volume are both determined based on the opening of the engine throttle valve, and the second intake volume and the fourth intake volume are both determined based on the pressure of the engine intake manifold. The fault detection result of the fuel tank air replenishment channel is determined based on the first ratio and the second ratio.

[0055] The intake volume determination paths corresponding to the first and third intake volumes are different from those corresponding to the second and fourth intake volumes. Specifically, the path that determines the intake volume based on the throttle opening measures the amount of air passing through the throttle section, and it cannot sense the airflow that merges into the intake manifold downstream of the throttle. The path that determines the intake volume based on the intake manifold pressure measures the amount of air actually charged into the cylinder, and it can sense the desorbed airflow that merges into the intake manifold through the carbon canister valve.

[0056] For example, when the carbon canister valve is open to zero, no desorbed airflow enters the intake manifold. Due to the conservation of gas mass, the mass of air passing through the throttle valve is equal to the mass of air entering the cylinder. The first intake volume and the second intake volume are basically the same, and the first ratio is stable near the reference value.

[0057] For example, if the carbon canister valve is fully open and the fuel tank air supply channel is unobstructed, the air supply airflow carrying fuel vapor enters the intake manifold through the carbon canister valve. This portion of the airflow is not measured by the path based on the throttle model, so the third intake volume remains essentially unchanged relative to the first intake volume. However, the increased pressure in the intake manifold causes the fourth intake volume to increase relative to the second intake volume, resulting in a significant change in the second ratio relative to the first ratio. If the fuel tank air supply channel is blocked, even with the carbon canister valve fully open, air supply airflow cannot be introduced, and the second ratio is essentially the same as the first ratio. Therefore, the blockage status of the fuel tank air supply channel can be determined based on the first and second ratios.

[0058] In some embodiments, the first ratio and the second ratio may be ratios calculated from a single sampling. In other embodiments, to reduce the impact of signal fluctuations on the detection results, the first ratio and the second ratio may also be the average of multiple ratios within a preset running time in the corresponding state. For example, the engine controller may continuously calculate the ratio of intake air volume at multiple sampling times within a preset running time, integrate and accumulate the multiple ratios, and then average them to obtain the average steady-state deviation as the corresponding ratio. The preset running time may be set to 5 seconds, or it may be calibrated according to actual test conditions.

[0059] Specifically, the preset running time can be set according to the fluctuation of the ratio. If the fluctuation of the ratio is observed to be within 5% during the test, the engine can be considered to be in a stable state. If the fluctuation of the ratio is more drastic, the preset running time can be shortened appropriately. If the fluctuation of the ratio is not drastic, the preset running time can be extended appropriately to improve the accuracy of the test.

[0060] This embodiment determines the ratio of two intake volumes through two different intake volume determination paths to achieve fault detection of the fuel tank replenishment channel. Both paths reuse the calculation parameters of the engine controller, eliminating the need for additional sensors.

[0061] In one possible implementation, obtaining the first intake information of the vehicle's engine in the first state includes: It acquires the throttle opening, the pressure on the intake side of the throttle, and the temperature on the intake side of the throttle; and it acquires the intake manifold pressure and the engine speed. The first intake volume is determined based on the throttle opening, the pressure on the intake side of the throttle, and the temperature on the intake side of the throttle. The second intake volume is determined based on the intake manifold pressure and engine speed.

[0062] The opening degree of the above-mentioned throttle can be collected by a throttle position sensor arranged in conjunction with the throttle 106. The intake side of the throttle refers to the side close to the throttle when air flows into the throttle through the air filter, that is, the side of the throttle close to the air filter; correspondingly, the side of the throttle close to the intake manifold is the outlet side of the throttle. The pressure and temperature on the intake side of the throttle can be collected by a temperature and pressure sensor arranged on the intake pipe on the intake side of the throttle.

[0063] In some embodiments, for vehicle models that are not equipped with a temperature and pressure sensor on the intake side of the throttle, the pressure on the intake side of the throttle can be approximately replaced by the ambient pressure, and the temperature on the intake side of the throttle can be approximately replaced by the ambient temperature. The ambient pressure and the ambient temperature can be respectively collected by the existing ambient pressure sensor and ambient temperature sensor of the vehicle, which can further reduce the dependence on hardware.

[0064] The pressure of the above-mentioned intake manifold can be collected by a manifold pressure sensor, and the rotational speed of the engine can be collected by a crankshaft position sensor.

[0065] Exemplarily, the calculation of the first intake air amount can be expressed as follows: ; Wherein: msdk represents the first intake air amount; Aeff represents the effective intake area of the throttle, the effective intake area is determined according to the opening degree of the throttle, and the corresponding relationship between the opening degree of the throttle and the effective intake area can be pre-calibrated and stored in the engine controller; Pup represents the absolute pressure value on the intake side of the throttle; Tup represents the absolute temperature value on the intake side of the throttle; Csub(r) represents a coefficient related to the pressure ratio before and after the throttle, which is used to describe the compressibility and throttling effect when gas flows through the throttle, and r represents the pressure ratio between the pressure on the outlet side and the pressure on the intake side of the throttle.

[0066] Exemplarily, the calculation of the second intake air amount can be expressed as follows: ; Wherein: ml represents the second intake air amount; Pman represents the absolute pressure of the intake manifold; Vd represents the displacement of the engine; ηvol represents the volumetric efficiency of the engine, and the volumetric efficiency can be obtained by querying a pre-calibrated volumetric efficiency table according to parameters such as the rotational speed of the engine and the pressure of the intake manifold; N represents the rotational speed of the engine; Tman represents the absolute temperature of the gas inside the intake manifold.

[0067] In one possible implementation, the fault detection result of the fuel tank air supply channel is determined based on a first ratio and a second ratio, including: The fault detection result of the fuel tank air replenishment channel is determined based on the target difference and the preset difference threshold; where the target difference is the absolute value of the difference between the first ratio and the second ratio.

[0068] Specifically, after determining the first ratio and the second ratio, the engine controller calculates the difference between the second ratio and the first ratio, and takes the absolute value of the difference as the target difference. The preset difference threshold can be determined through calibration.

[0069] This embodiment determines the fault detection result by comparing the difference between the second ratio and the first ratio with a preset difference threshold. The decision logic is simple, the amount of computation is small, it is easy to implement, and it uses the absolute value as the comparison object, so there is no need to care about the positive or negative direction of the difference, and it can be compatible with the signal definition differences of different vehicle models.

[0070] In one possible implementation, the fault detection result of the fuel tank air supply channel is determined based on the target difference and a preset difference threshold, including: If the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

[0071] As mentioned earlier, when the fuel tank air supply channel is unobstructed, increasing the opening of the canister valve introduces airflow that bypasses the throttle valve, significantly increasing the intake air volume determined based on the intake manifold pressure, resulting in a larger target difference. Conversely, when the fuel tank air supply channel is blocked, increasing the canister valve opening fails to introduce airflow, and the calculation results for the two paths are essentially synchronized, resulting in a smaller target difference. Therefore, a target difference less than a preset difference threshold can be used as a criterion for determining whether the fuel tank air supply channel is blocked.

[0072] To avoid misjudgments caused by instantaneous signal fluctuations, in some embodiments, the engine controller may only determine that there is a blockage in the fuel tank air supply passage if the target difference is less than a preset difference threshold and remains so for a preset duration. The specific value of the preset duration can be calibrated, and it can be set as a duration mapping table corresponding to altitude and ambient temperature. The engine controller can look up the corresponding preset duration from the duration mapping table based on the vehicle's altitude and ambient temperature.

[0073] In some embodiments, the preset difference threshold can be calibrated as follows: Prepare samples with unblocked fuel tank air supply channels and samples with blocked fuel tank air supply channels respectively. Record the ratio of the unblocked sample in the first state and the ratio in the second state. Then record the ratio of the blocked sample in the first state and the ratio in the second state. Calculate the difference between the second ratio and the first ratio of the two different state samples. If the difference between the deviations corresponding to the two samples is stable at more than 10%, it indicates that the detection distinction between the unblocked state and the blocked state is sufficient. Based on this, the preset difference threshold can be determined. For example, the preset difference threshold can be determined as the median value of the deviations corresponding to the two samples.

[0074] In other embodiments, instead of calculating the absolute value of the difference, the judgment can be made directly based on the relationship between the second ratio and the first ratio. For example, if the second ratio is greater than the sum of the first ratio and a preset deviation value for a preset duration, it is determined that the fuel tank air supply passage is blocked. The preset deviation value can also be determined through the aforementioned sample comparison calibration method. It is understood that the specific comparison method can be flexibly selected based on the signal definitions and calibration data of different vehicle models, as long as the comparison result can distinguish between the unobstructed and blocked states of the fuel tank air supply passage.

[0075] This embodiment further improves the accuracy and reliability of fault detection results by determining the blockage judgment conditions.

[0076] In one possible implementation, if the target difference is less than a preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked, including: Based on the ambient pressure of the vehicle's environment and the fuel level information in the vehicle's fuel tank, a preset difference threshold is determined from a preset mapping relationship that corresponds to both the ambient pressure and the fuel level information. The preset mapping relationship includes the mapping relationship between the ambient pressure, the fuel level information, and the difference threshold, respectively. In response to obtaining a preset difference threshold, if the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

[0077] The aforementioned environmental pressure can be obtained from the vehicle's existing environmental pressure sensor. Environmental pressure is related to the vehicle's altitude; the higher the altitude, the lower the environmental pressure and the lower the air density. Consequently, the mass flow rate of the supplementary airflow introduced at the same carbon canister valve opening is also smaller, affecting the deviation between the two ratios differently. Fuel tank level information can be obtained from the fuel tank level sensor. Different fuel tank levels result in different volumes of the vapor phase space within the tank, affecting the rate of negative pressure build-up and the buffering capacity of the supplementary airflow.

[0078] The preset mapping relationship can be established through pre-calibration. For example, under different environmental pressures and different fuel levels, the fuel tank air supply passage is tested for both unobstructed and blocked states. The appropriate detection threshold for each combination of environmental pressure and fuel level is calibrated, forming a correspondence between environmental pressure, fuel level information, and the difference threshold. This correspondence is then stored in the engine controller in the form of a mapping table.

[0079] When the engine controller performs fault detection, it retrieves the corresponding difference threshold from a preset mapping relationship based on the collected ambient pressure and fuel level information. Then, it compares the target difference with the preset difference threshold. This comparison, performed under the same fuel tank level, eliminates interference from differences in vapor phase volume, thus improving the accuracy of fault detection.

[0080] This embodiment improves the accuracy of fault detection by adaptively adjusting the preset difference threshold according to the ambient pressure and the fuel tank level information, eliminating the influence of altitude, air pressure changes and differences in the volume of the gas phase space in the fuel tank on the decision criteria.

[0081] In one possible implementation, if the target difference is less than a preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked, including: Based on the environmental pressure of the vehicle's environment and the fuel level information of the vehicle's fuel tank, the preset initial difference threshold is corrected to obtain the preset difference threshold; wherein, the preset initial difference threshold is the difference threshold obtained by calibration under preset environmental pressure and preset fuel level information. In response to obtaining a preset difference threshold, if the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

[0082] The aforementioned preset initial difference threshold is a difference threshold calibrated under reference environmental conditions. For example, the preset environmental pressure can be standard atmospheric pressure, and the preset liquid level information can be half the tank volume. Under the reference conditions of standard atmospheric pressure and half the tank volume, the preset initial difference threshold is determined according to the aforementioned sample comparison calibration method.

[0083] The correction methods can include several approaches. In one embodiment, the correspondence between environmental pressure and liquid level information and correction coefficients can be pre-calibrated. The engine controller queries the corresponding correction coefficients based on the collected environmental pressure and liquid level information, and multiplies the preset initial difference threshold by the correction coefficients to obtain the preset difference threshold. In another embodiment, the correspondence between environmental pressure and liquid level information and correction amounts can be pre-calibrated, and the preset initial difference threshold can be added to the correction amount to obtain the preset difference threshold. In yet another embodiment, the preset difference threshold can also be directly calculated based on a preset functional relationship between environmental pressure, liquid level information, and the preset difference threshold.

[0084] This embodiment can correct the preset difference threshold based on the preset initial difference threshold and the corresponding correction relationship. It does not require storing a large-capacity mapping table, has low storage overhead, and is suitable for engine controllers with limited storage resources. It can also achieve adaptive adjustment of the threshold according to environmental pressure and liquid level information.

[0085] In one possible implementation, the fault detection result of the fuel tank air supply channel is determined based on a first ratio and a second ratio, including: The oxygen content information in the engine exhaust is obtained using the vehicle's oxygen sensor. Based on the oxygen content information, the first fuel correction amount of the engine in the first state and the second fuel correction amount of the engine in the second state are determined; wherein, the first fuel correction amount and the second fuel correction amount are both correction amounts for adjusting the fuel injection amount based on the oxygen content information, and the opening degree of the carbon canister valve in the first state is smaller than the opening degree of the carbon canister valve in the second state. Based on the first fuel correction amount and the second fuel correction amount, determine the change information of the fuel correction amount; Based on the first ratio, the second ratio, and the change information in fuel correction amount, the fault detection result of the vehicle's fuel tank air replenishment channel is determined.

[0086] The first and second fuel injection correction amounts mentioned above are both corrections made to the fuel injection quantity based on oxygen content information. In the first state, the opening degree of the canister carbon valve is smaller than that in the second state. An oxygen sensor is installed in the engine's exhaust passage to collect oxygen content information in the exhaust. The engine controller performs closed-loop control of the engine's air-fuel ratio based on the oxygen content information: when the oxygen content in the exhaust is high (i.e., the mixture is lean), the engine controller increases the fuel injection quantity; when the oxygen content in the exhaust is low (i.e., the mixture is rich), the engine controller decreases the fuel injection quantity. This closed-loop control is an existing function in engine fuel injection control.

[0087] The aforementioned fuel trim amount is the trim amount by which the engine controller corrects the fuel injection quantity during the closed-loop control process, and can be, for example, a short-term fuel trim value. The first fuel trim amount is the fuel trim amount in the first state, and the second fuel trim amount is the fuel trim amount in the second state. Since the opening of the canister valve in the first state is smaller than that in the second state, when the fuel tank air supply passage is unobstructed, after the canister valve opening increases, the desorbed gas flow carries a large amount of fuel vapor into the cylinder to participate in combustion, resulting in a richer mixture. The engine controller reduces the fuel injection quantity, and the second fuel trim amount changes relative to the first fuel trim amount in the direction of reducing the fuel injection quantity. This trim state persists as long as the desorbed gas flow continues to be introduced. When the fuel tank air supply passage is blocked, in the initial stage of increasing the canister valve opening, only a small amount of residual fuel vapor in the canister is drawn into the cylinder. The second fuel trim amount changes briefly in the direction of reducing the fuel injection quantity. After the residual vapor is consumed, it returns to the trim level in the first state, and the duration of the change is short.

[0088] The aforementioned information on changes in fuel trim may include one or more of the following: the amount of change of the second fuel trim relative to the first fuel trim, the direction of change, and the duration of the change. The engine controller integrates the airflow characteristics reflected by the two ratios with the combustion characteristics reflected by the fuel trim change information to jointly determine the fault detection result. It can be understood that the two ratios reflect the airflow characteristic of whether the supplementary airflow enters the intake system, while the fuel trim change information reflects the combustion characteristic of whether the fuel vapor carried by the desorbed airflow participates in combustion, thus enabling the determination of the fault detection result from different dimensions.

[0089] This embodiment uses oxygen sensor to collect oxygen content information and determines its change information through fuel correction amount in the first and second states. By combining the first ratio, the second ratio and the change information of fuel correction amount, compared with the judgment method that relies solely on air path deviation, it can effectively distinguish the ratio deviation caused by blockage of fuel tank air supply channel and other reasons, further improving the specificity of fault detection and reducing false alarm rate.

[0090] In one possible implementation, the fault detection result of the vehicle's fuel tank air supply passage is determined based on a first ratio, a second ratio, and information on changes in fuel trim, including: If the first ratio, the second ratio, and the change information of fuel correction amount meet the preset conditions, the fault detection result of the vehicle's fuel tank air replenishment passage is determined to be: there is a blockage in the fuel tank air replenishment passage; The preset conditions include at least the following: The absolute value of the difference between the first ratio and the second ratio is less than a preset difference threshold; The change information of fuel trim indicates that the fuel trim is changing in the direction of reducing the amount of fuel injected by the engine, and the duration of the change in fuel trim is less than a preset duration threshold.

[0091] The aforementioned preset conditions include two sub-conditions. The first sub-condition is consistent with the judgment condition for the target difference in the previous embodiment, and is used to characterize the characteristic that the calculated results of the two intake air volumes before and after the change in the carbon canister valve opening do not show a significant deviation. The second sub-condition is used to characterize the combustion characteristic where the desorbed airflow only carries residual fuel vapor and participates in combustion briefly: when the fuel tank air supply channel is blocked, after the carbon canister valve opening increases, the residual fuel vapor in the carbon canister is drawn into the cylinder, the air-fuel mixture is temporarily rich, and the fuel correction amount changes in the direction of reducing the fuel injection amount, but the residual vapor is quickly consumed, and the correction state disappears, so the duration of the change is short; when the fuel tank air supply channel is unobstructed, the air supply airflow continuously carries fuel vapor into the cylinder, and the correction state of the fuel correction amount in the direction of reducing the fuel injection amount persists, so the duration of the change is long. The preset duration threshold can be determined by calibration, for example, the duration of the correction state can be collected in the unobstructed state and the blocked state, and the value between the two can be taken as the preset duration threshold.

[0092] A blockage in the fuel tank air supply passage is determined only if both sub-conditions are met simultaneously. If only the first sub-condition is met but the second sub-condition is not, for example, if the absolute value of the difference is small but the correction state persists, the ratio shift may be due to other reasons and will not be considered a blockage.

[0093] In some embodiments, the fault detection results may also include other fault types besides blockage of the fuel tank air supply passage, in order to isolate the cause of the fault.

[0094] For example, if the difference between the first ratio and the second ratio is not related to the opening adjustment of the carbon canister valve, and the change information of the fuel trim indicates that the fuel trim is continuously corrected in the direction of increasing the amount of fuel injected by the engine, it can be determined that the fault detection result is that there is a leak in the engine's intake system. This is because an intake system leak will introduce unmetered air, making the air-fuel mixture continuously lean, which is significantly different from the characteristics of a blocked fuel tank air supply passage.

[0095] For another example, if the first ratio has a slow offset that is not related to the opening adjustment of the carbon canister valve and the fuel trim amount does not change synchronously, the fault detection result can be determined to be that there is carbon deposit on the throttle valve or that the intake air volume of the engine is drifting. This is because the ratio offset caused by carbon deposits and metering drift is formed slowly over time and has no time correlation with the adjustment action of the carbon canister valve.

[0096] This embodiment further defines the fusion judgment conditions as the gas path difference condition and the combustion correction condition. Only when both conditions are met simultaneously can a blockage be determined, which can accurately determine whether there is a blockage in the fuel tank air supply channel.

[0097] In one possible implementation, after determining the fault detection result of the vehicle's fuel tank air supply passage, the method further includes: In response to the fault detection result indicating that the fuel tank air supply passage of the vehicle is blocked, the desorption adjustment parameters are determined based on the ambient temperature of the vehicle's environment, the pressure of the engine's intake manifold, the engine speed, and the fuel level information of the vehicle's fuel tank. Adjust the working state of the carbon canister valve according to the desorption adjustment parameters.

[0098] The aforementioned desorption adjustment parameters are used to adjust the desorption intensity of the carbon canister. Considering that: ambient temperature affects the fuel evaporation rate and the amount of vapor generated in the fuel tank; the intake manifold pressure directly determines the negative pressure required to extract fuel vapor from the carbon canister; engine speed affects the number of extraction cycles per unit time; and the fuel tank level reflects the volume of the vapor phase space within the tank—the smaller the vapor phase space volume, the faster the negative pressure rises in the tank for the same desorption intensity—this embodiment determines the desorption adjustment parameters based on ambient temperature, intake manifold pressure, engine speed, and fuel tank level information.

[0099] In some embodiments, a comprehensive mapping table can be pre-calibrated by combining ambient temperature, intake manifold pressure, engine speed, and fuel tank level information. The engine controller queries the comprehensive mapping table for the corresponding desorption adjustment parameters based on these four parameters. The engine controller adjusts the operating state of the canister carbon valve according to the desorption adjustment parameters, such as limiting the opening degree of the canister carbon valve, limiting the opening duration of the canister carbon valve, or suspending the opening of the canister carbon valve, in order to reduce the intensity of canister carbon desorption and prevent excessive negative pressure in the fuel tank from damaging the fuel tank.

[0100] In some embodiments, if the fault detection result indicates that the fuel tank air supply passage is blocked, the engine controller can also generate a prompt message to remind the driver to inspect the fuel tank air supply passage. For example, the engine controller can control the illumination of a fault indicator light on the vehicle's dashboard, such as illuminating the vehicle's SVS light, to remind the driver to promptly visit a service station to have the fuel tank air supply passage repaired; alternatively, the fault detection result can be stored as a fault code for retrieval by maintenance personnel using a diagnostic tool.

[0101] This embodiment, after confirming the blockage, comprehensively determines the desorption adjustment parameters based on ambient temperature, intake manifold pressure, engine speed, and fuel tank level information, and adjusts the working state of the carbon canister valve. This can actively suppress the continued increase of negative pressure in the fuel tank, avoid fuel tank deformation and damage, and simultaneously meet the control requirements of evaporative emissions.

[0102] In one possible implementation, the desorption adjustment parameters include at least adjusting the opening degree and adjusting the desorption duration, wherein the adjusting desorption duration is used to limit the cumulative duration for which the carbon canister valve is in the open state; Adjust the operating status of the carbon canister valve according to the desorption adjustment parameters, including: Adjust the opening of the carbon canister valve to the adjusted opening, and control the cumulative duration for which the carbon canister valve maintains the adjusted opening to be less than or equal to the adjusted desorption duration.

[0103] Specifically, the accumulated negative pressure in the fuel tank is determined by both the flow rate of the desorbed gas stream and the duration of desorption. Adjusting the valve opening limits the flow rate of the desorbed gas stream entering the intake manifold via the carbon canister valve per unit time; a smaller opening results in a lower pumping rate per unit time. Adjusting the desorption duration limits the cumulative duration of the desorption process, preventing prolonged low-intensity desorption from causing negative pressure accumulation. Therefore, the desorption adjustment parameters need to include both the valve opening and the desorption duration.

[0104] In some embodiments, a comprehensive mapping table of the longest desorption time and the maximum carbon canister valve opening can be pre-calibrated by combining ambient temperature, intake manifold pressure, engine speed and fuel tank level information. The engine controller queries the corresponding maximum carbon canister valve opening from the comprehensive mapping table based on the collected four parameters to adjust the opening, and queries the corresponding longest desorption time to adjust the desorption duration. By limiting the maximum desorption intensity through this comprehensive mapping table, the purpose of protecting the fuel tank can be achieved.

[0105] In this embodiment, after the engine controller adjusts the opening of the carbon canister valve to the adjusted opening, it times the cumulative duration for which the carbon canister valve maintains the adjusted opening. When the cumulative duration reaches the adjusted desorption time, the carbon canister valve is closed, or the opening of the carbon canister valve is reduced to a smaller opening, allowing the pressure in the fuel tank to have a chance to return to equilibrium. After the pressure in the fuel tank recovers, desorption can be performed again according to the desorption adjustment parameters, thereby protecting the fuel tank while preserving the desorption capability as much as possible.

[0106] In one possible implementation, before acquiring the first intake information of the vehicle's engine in the first state, the method further includes: Obtain multiple engine speeds, multiple loads, and engine throttle opening within a preset statistical time period; The engine speed fluctuation value is determined based on multiple speeds, and the engine load fluctuation value is determined based on multiple loads; If the speed fluctuation value is less than the preset speed fluctuation threshold and the load fluctuation value is less than the preset load fluctuation threshold, the vehicle is determined to be in the first state.

[0107] The aforementioned preset statistical duration is the continuous duration used to determine whether the engine is in a steady state; for example, it can be 3 seconds. The specific value of the preset statistical duration can be calibrated and set according to ambient temperature and altitude to ensure that the detection can be completed within the preset statistical duration. Within the preset statistical duration, the engine controller continuously collects multiple engine speeds and multiple loads according to a preset sampling period.

[0108] The engine speed can be obtained from the crankshaft position sensor. Engine load is the ratio of the actual intake air volume at a given engine speed to the maximum intake air volume at that speed, usually expressed as a percentage, and can be calculated by the engine controller based on existing intake air volume measurements. Throttle opening can be obtained from the throttle position sensor.

[0109] The aforementioned speed fluctuation value is used to characterize the degree of fluctuation of engine speed within a preset statistical period, and the load fluctuation value is used to characterize the degree of fluctuation of engine load within a preset statistical period. The fluctuation value can be calculated in various ways. For example, the difference between the maximum and minimum values ​​within the preset statistical period can be used as the fluctuation value, or the standard deviation of multiple values ​​within the preset statistical period can be used as the fluctuation value.

[0110] The aforementioned preset speed fluctuation threshold and preset load fluctuation threshold can be calibrated and selected according to different engines. For example, the preset speed fluctuation threshold can be set to 50 revolutions per minute, and the preset load fluctuation threshold can be set to 5%. When the speed fluctuation value is less than 50 revolutions per minute and the load fluctuation value is less than 5%, the engine can be considered to be in a steady-state condition, that is, the vehicle is determined to be in the first state.

[0111] In some embodiments, the first state can also be determined by combining the engine speed range and the throttle opening. For example, for a non-turbocharged engine, the engine speed can be selected to be between 2000 rpm and 4000 rpm; the specific range for different engines needs to be calibrated. The throttle opening should not be too large, and can be required to not exceed 20%, for example, selecting a throttle opening of 10% to ensure that the negative pressure after the throttle can be stably drawn from the fuel tank. The engine speed can be selected from commonly used steady-state operating conditions, and the detection discrimination under different operating conditions can be compared to select the operating condition with better detection discrimination as the detection operating condition.

[0112] This embodiment calculates fluctuation values ​​by continuously collecting multiple speeds and multiple loads within a preset statistical time period, and determines the first state by combining conditions such as speed range and throttle opening, which can indirectly improve the accuracy of fault detection.

[0113] In some embodiments, after determining that there is a blockage in the fuel tank air supply passage, the engine controller may illuminate the vehicle powertrain malfunction warning light to remind the driver to repair it in a timely manner.

[0114] It should be noted that for vehicles in high emission standard areas equipped with fuel tank pressure sensors, in the event of a fuel tank pressure sensor failure, the fault detection method provided in this application embodiment can also be used as a temporary alternative detection method to continue to detect faults in the fuel tank air supply channel, ensuring that the fault detection function is not interrupted.

[0115] It should be noted that the various embodiments described in this application can be combined with each other or implemented individually without conflict, and this application does not limit this.

[0116] Corresponding to the above method embodiments, this application also provides a fault detection system. Please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is a functional module diagram of a fault detection system 300 provided in an embodiment of this application. The fault detection system 300 includes: The response module 310 is used to respond to receiving a fault detection command by acquiring the first intake information of the vehicle's engine in a first state; and acquiring the second intake information of the engine in a second state; wherein the opening degree of the carbon canister valve of the vehicle is different in the first state and the second state. The determination module 320 is used to determine the fault detection result of the vehicle's fuel tank air replenishment channel based on the first air intake information and the second air intake information.

[0117] The fault detection system provided in this application embodiment can achieve the following: Figure 1 The various processes implemented in the Chinese method embodiments can achieve similar or the same technical effects, and will not be described again here to avoid repetition.

[0118] In addition to the methods and systems provided in the above embodiments, this application also provides an engine controller. Please refer to... Figure 4 , Figure 4 This is a schematic diagram of the hardware structure of an engine controller provided in an embodiment of this application.

[0119] The engine controller may include a processor 401 and a memory 402 storing computer program instructions.

[0120] Specifically, the processor 401 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0121] Memory 402 may include mass storage for data or instructions. For example, and not limitingly, memory 402 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 402 may include removable or non-removable (or fixed) media. Where appropriate, memory 402 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 402 is non-volatile solid-state memory.

[0122] In some embodiments, memory 402 may include read-only memory (ROM), random access memory (RAM), disk storage media device, optical storage media device, flash memory device, electrical, optical, or other physical / tangible memory storage device. Therefore, generally, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described in the methods provided according to embodiments of this application.

[0123] The processor 401 implements the method provided in the above embodiments by reading and executing computer program instructions stored in the memory 402.

[0124] In one example, the engine controller may also include a communication interface 403 and a bus 410. The processor 401, memory 402, and communication interface 403 are connected via the bus 410 and communicate with each other.

[0125] The communication interface 403 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0126] Bus 410 includes hardware, software, or both, that couples components of the engine controller together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 410 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0127] Furthermore, in conjunction with the methods provided in the above embodiments, this application embodiment can be implemented using a computer-readable storage medium. This computer-readable storage medium stores computer program instructions; when executed by a processor, these computer program instructions implement any of the methods in the above embodiments.

[0128] Furthermore, in conjunction with the methods provided in the above embodiments, this application embodiment can provide a computer program product to implement the methods. This program product is stored in a storage medium and executed by at least one processor to implement the various processes of the embodiments of the methods provided in the above embodiments, achieving similar or identical technical effects. To avoid repetition, further details are omitted here.

[0129] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0130] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0131] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0132] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0133] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A fault detection method, characterized in that, include: In response to receiving a fault detection command, the first intake information of the vehicle's engine in the first state is obtained; In addition, the second intake information of the engine in the second state is obtained; wherein the opening degree of the carbon canister valve of the vehicle in the first state and the second state are different; Based on the first air intake information and the second air intake information, the fault detection result of the fuel tank air replenishment channel of the vehicle is determined.

2. The method as described in claim 1, characterized in that, The first intake information includes a first intake volume and a second intake volume, and the second intake information includes a third intake volume and a fourth intake volume; The step of determining the fault detection result of the vehicle's fuel tank air replenishment channel based on the first air intake information and the second air intake information includes: A first ratio of the first intake volume to the second intake volume is determined, and a second ratio of the third intake volume to the fourth intake volume is determined; wherein the first intake volume and the third intake volume are both determined based on the opening of the engine throttle valve, and the second intake volume and the fourth intake volume are both determined based on the pressure of the engine intake manifold. The fault detection result of the fuel tank air replenishment channel is determined based on the first ratio and the second ratio.

3. The method as described in claim 2, characterized in that, The acquisition of the first intake information of the vehicle's engine in the first state includes: The throttle valve opening, the intake side pressure of the throttle valve, and the intake side temperature of the throttle valve are obtained; and the intake manifold pressure and the engine speed are obtained. The first intake volume is determined based on the throttle opening, the pressure on the intake side of the throttle, and the temperature on the intake side of the throttle. The second intake volume is determined based on the pressure in the intake manifold and the engine speed.

4. The method as described in claim 2, characterized in that, The step of determining the fault detection result of the fuel tank air supply channel based on the first ratio and the second ratio includes: The fault detection result of the fuel tank air replenishment channel is determined based on the target difference and the preset difference threshold; wherein, the target difference is the absolute value of the difference between the first ratio and the second ratio.

5. The method as described in claim 4, characterized in that, The step of determining the fault detection result of the fuel tank air replenishment channel based on the target difference and a preset difference threshold includes: If the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

6. The method as described in claim 5, characterized in that, When the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked, including: Based on the ambient pressure of the vehicle's environment and the fuel level information of the vehicle's fuel tank, a preset difference threshold is determined from a preset mapping relationship that corresponds to both the ambient pressure and the fuel level information; wherein, the preset mapping relationship includes the mapping relationship between the ambient pressure, the fuel level information and the difference threshold respectively; In response to obtaining the preset difference threshold, if the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

7. The method as described in claim 5, characterized in that, When the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked, including: Based on the ambient pressure of the vehicle's environment and the fuel level information of the vehicle's fuel tank, the preset initial difference threshold is corrected to obtain the preset difference threshold; wherein, the preset initial difference threshold is a difference threshold obtained by calibration under preset ambient pressure and preset fuel level information. In response to obtaining the preset difference threshold, if the target difference is less than the preset difference threshold, the fault detection result of the fuel tank air supply channel is determined to be: the fuel tank air supply channel is blocked.

8. The method as described in claim 2, characterized in that, The step of determining the fault detection result of the fuel tank air supply channel based on the first ratio and the second ratio includes: The oxygen content information in the exhaust gas of the engine is obtained, and the oxygen content information is collected using the oxygen sensor of the vehicle; Based on the oxygen content information, a first fuel correction amount for the engine in the first state and a second fuel correction amount for the engine in the second state are determined; wherein, both the first fuel correction amount and the second fuel correction amount are correction amounts for adjusting the fuel injection amount based on the oxygen content information, and the opening degree of the carbon canister valve in the first state is smaller than the opening degree of the carbon canister valve in the second state. Based on the first fuel correction amount and the second fuel correction amount, determine the change information of the fuel correction amount; Based on the first ratio, the second ratio, and the change information of the fuel correction amount, the fault detection result of the fuel tank air replenishment channel of the vehicle is determined.

9. The method as described in claim 8, characterized in that, The step of determining the fault detection result of the vehicle's fuel tank air replenishment channel based on the first ratio, the second ratio, and the change information of the fuel correction amount includes: If the first ratio, the second ratio, and the change information of the fuel correction amount meet the preset conditions, the fault detection result of the fuel tank air supply channel of the vehicle is determined to be: the fuel tank air supply channel is blocked; The preset conditions include at least the following: The absolute value of the difference between the first ratio and the second ratio is less than a preset difference threshold; The change information of the fuel correction amount indicates that the fuel correction amount changes in the direction of reducing the fuel injection amount of the engine, and the duration of the change of the fuel correction amount is less than a preset duration threshold.

10. The method as described in claim 1, characterized in that, After determining the fault detection result of the vehicle's fuel tank air supply channel, the method further includes: In response to a fault detection result indicating that the fuel tank air supply passage of the vehicle is blocked, the desorption adjustment parameters are determined based on the ambient temperature of the vehicle's environment, the pressure of the engine's intake manifold, the engine speed, and the fuel level information of the vehicle's fuel tank. The operating state of the carbon canister valve is adjusted according to the desorption adjustment parameters.

11. The method as described in claim 10, characterized in that, The desorption adjustment parameters include at least the adjustment opening degree and the adjustment desorption duration, wherein the adjustment desorption duration is used to limit the cumulative duration for which the carbon canister valve is in the open state; Adjusting the operating state of the carbon canister valve according to the desorption adjustment parameter includes: The opening degree of the carbon canister valve is adjusted to the adjusted opening degree, and the cumulative duration for which the carbon canister valve maintains the adjusted opening degree is less than or equal to the adjusted desorption duration is controlled.

12. The method as described in claim 1, characterized in that, Before acquiring the first intake information of the vehicle's engine in the first state, the method further includes: The engine's multiple speeds, multiple loads, and throttle opening are obtained within a preset statistical time period. The engine speed fluctuation value is determined based on the plurality of speeds, and the engine load fluctuation value is determined based on the plurality of loads; If the speed fluctuation value is less than a preset speed fluctuation threshold and the load fluctuation value is less than a preset load fluctuation threshold, the vehicle is determined to be in the first state.

13. A fault detection system, characterized in that, include: The response module is used to respond to the received fault detection command and obtain the first intake information of the vehicle's engine in the first state; In addition, the second intake information of the engine in the second state is obtained; wherein the opening degree of the carbon canister valve of the vehicle in the first state and the second state are different; The determination module is used to determine the fault detection result of the fuel tank air replenishment channel of the vehicle based on the first air intake information and the second air intake information.

14. An engine controller, characterized in that, The engine controller includes a memory and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the method of any one of claims 1 to 12.

15. An electronic device, characterized in that, The electronic device includes the engine controller as described in claim 14.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by one or more processors, implements the method of any one of claims 1 to 12.

17. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by one or more processors, implements the method of any one of claims 1 to 12.

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