A fault monitoring method, device, medium and vehicle control unit for FTIV valves and CPV valves

Abstract

The present application relates to the technical field of automobile fault monitoring, and particularly relates to a fault monitoring method and device for FTIV valves and CPV valves, a medium and a vehicle controller. When passive fault monitoring enabling conditions are met, passive fault monitoring is started for the FTIV valves and the CPV valves. When the passive fault monitoring enabling conditions are not met, but active fault monitoring enabling conditions are met, active fault monitoring is started for the FTIV valves and the CPV valves. The active fault monitoring is continuously completed multiple times by opening and closing the FTIV valves and the CPV valves in turn. In the present application, the combination of the passive fault monitoring and the active fault monitoring scheme, and the close cooperation of the FTIV valve and the CPV valve control can minimize the opportunity of diagnosing and actively intervening in the control of the two valves, thereby reducing the influence on the mixed gas control and the evaporative emission, and further improving the diagnosis opportunity.

Description

Technical Field

[0001] This invention relates to the field of automotive fault monitoring technology, and in particular to a fault monitoring method, device, medium, and vehicle controller for FTIV valves and CPV valves. Background Technology

[0002] Currently, hybrid vehicles are becoming increasingly common. Because their engines operate less frequently, traditional carbon canister adsorption and desorption alone are insufficient to meet regulatory requirements for evaporative emissions. To meet these requirements, the mainstream evaporative emission system hardware configuration currently employs a high-pressure fuel tank, a fuel tank isolation valve (FTIV valve), and a fuel tank pressure sensor. The FTIV valve is a normally closed valve, meaning it is closed by default and only opens when an opening command is sent. When the engine is not running, the generated fuel vapor is trapped in the fuel tank by the FTIV valve, preventing leakage and reducing the load on the carbon canister. When the engine is running or the fuel tank pressure is high, the system will open the FTIV valve to desorb the fuel vapor in the tank and reduce the tank pressure. Therefore, the FTIV valve is a key component affecting evaporative emissions, and thus requires fault monitoring.

[0003] For regulations and standards such as China VI emission standard / OBDII that require evaporative leakage monitoring, the evaporative systems of these hybrid vehicles are typically equipped with hardware such as DMTL pumps / ELCM pumps to monitor leakage faults in order to meet the requirements for evaporative leakage diagnosis. The system can also monitor FTIV valve responsiveness faults based on this hardware. However, for regulations and standards such as EOBD that do not have this requirement for evaporative leakage monitoring, the lack of hardware such as DMTL pumps means that it is impossible to monitor FTIV valve responsiveness faults based on this hardware. Summary of the Invention

[0004] This invention discloses a fault monitoring method, device, medium, and vehicle controller for FTIV valves and CPV valves, which can solve the problem that hybrid vehicle engines cannot monitor FTIV valve and CPV valve faults in a timely manner due to their short operating time.

[0005] To achieve the above objectives, on the one hand, a fault monitoring method for FTIV valves and CPV valves is provided, the specific method of which is as follows:

[0006] When the passive fault monitoring enable condition is met, passive fault monitoring is activated for FTIV valves and CPV valves.

[0007] When the passive fault monitoring enable condition is not met, but the active fault monitoring enable condition is met, active fault monitoring is enabled for FTIV valves and CPV valves.

[0008] The passive fault monitoring utilizes the evaporation system's own control requirements to open the FTIV valve, diagnosing whether the FTIV valve has a fault and the type of fault.

[0009] The active fault monitoring proactively opens and closes the FTIV valve and CPV valve in sequence according to diagnostic needs, and diagnoses whether the FTIV valve and CPV valve have faults and the type of fault.

[0010] The advantage of this embodiment is that the engine of the hybrid vehicle may not work for a long time. When the passive fault monitoring enable conditions are not met, active fault monitoring can be introduced to ensure the timeliness of fault monitoring of the FTIV valve and CPV valve.

[0011] Furthermore, the passive fault monitoring enabling conditions include: when the absolute value of the tank pressure is greater than or equal to the first pressure threshold, the carbon canister flushing requirement causes the FTIV valve to open, or when the absolute value of the tank pressure is greater than or equal to the first pressure threshold, the refueling requirement causes the FTIV valve to open to release pressure.

[0012] Specifically, the passive fault monitoring method is as follows:

[0013] Open the FTIV valve;

[0014] If the pressure difference before and after the FTIV valve opens is greater than or equal to the second pressure threshold, then the FTIV valve is diagnosed as fault-free.

[0015] If the pressure difference before and after the FTIV valve opens is less than the second pressure threshold, the duration exceeds the first time threshold, and no oil tank pressure signal sticking fault is detected, then the FTIV valve stuck normally closed fault is diagnosed.

[0016] If the pressure difference before and after the FTIV valve opens is less than the second pressure threshold, the duration exceeds the first time threshold, and a viscous fault in the tank pressure signal is detected, then the diagnostic process is exited.

[0017] Optionally, the active fault monitoring enabling conditions include: when the absolute value of the fuel tank pressure is greater than or equal to a first pressure threshold, the carbon canister flushing time exceeds a second time threshold, or the carbon canister load is less than a load threshold and the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold, or the engine running time exceeds a third time threshold and the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold.

[0018] Furthermore, the active fault monitoring performs the following operations in sequence:

[0019] Open the FTIV valve and perform the first diagnostic on the FTIV valve based on the pressure change;

[0020] Keep the FTIV valve open, close the CPV valve, and then gradually open the CPV valve. Based on the pressure changes, complete the second diagnosis of the FTIV and CPV valves.

[0021] Keep the FTIV valve open, close the CPV valve, and complete the third diagnostic for the CPV valve;

[0022] Close the FTIV valve and gradually open the CPV valve to complete the fourth diagnostic test of the FTIV valve.

[0023] The advantage of this embodiment is that the combination of passive and active fault monitoring schemes, as well as the close coordination of FTIV valve and CPV valve control, can minimize the chance of diagnosing and actively intervening in the operation of the two valves compared to independent fault monitoring, thereby reducing the impact on mixture control and evaporative emissions, and further improving the chance of diagnosis.

[0024] Furthermore, before the first diagnostic opens the FTIV valve, the engine must be run and the carbon canister flush activated to desorb combustion oil vapors.

[0025] Optionally, the first diagnosis can be performed using the following method:

[0026] Calculate the pressure change before and after the FTIV valve opens;

[0027] If the pressure change is greater than or equal to the third pressure threshold, the FTIV valve is considered to be fault-free.

[0028] If the pressure change is less than the third pressure threshold, then proceed to the second diagnostic step.

[0029] Furthermore, before the second diagnosis, it is necessary to determine whether the desorption vacuum conditions are met;

[0030] If the desorption vacuum condition is met, the second diagnosis will begin.

[0031] If the desorption vacuum condition is not met, return to the active fault monitoring enable condition judgment.

[0032] Furthermore, before the second diagnosis, it is determined whether the desorption vacuum conditions are met. The specific method is as follows:

[0033] If there is only one low desorption line, the desorption vacuum condition is determined based on the low desorption line. If there are two lines, high and low desorption, the desorption vacuum condition is determined by either the low desorption line or the high desorption line.

[0034] The low desorption pipeline determines whether the desorption vacuum condition is met based on the difference between the intake manifold pressure and atmospheric pressure.

[0035] The high desorption pipeline is used to determine whether the desorption vacuum condition is met based on the pressure difference between the high desorption pipeline and atmospheric pressure.

[0036] Furthermore, the second diagnosis is conducted using the following methods:

[0037] Keep the FTIV valve open and close the CPV valve to allow the tank pressure to stabilize and return to atmospheric pressure.

[0038] Keep the FTIV valve open, gradually open the CPV valve, and calculate the pressure difference across the tank. If the pressure difference across the tank is greater than or equal to the fourth pressure threshold, the FTIV valve is not stuck and normally closed. If the pressure difference across the tank is less than the fourth pressure threshold, the FTIV valve or CPV valve may be stuck and normally closed.

[0039] Furthermore, if the FTIV valve or CPV valve may be stuck and normally closed, determine whether the CPV valve or FTIV valve has a stuck and normally closed fault in turn.

[0040] If other monitoring schemes for CPV valves in the system have determined that the CPV valve has a stuck normally closed fault, then exit the diagnostic process.

[0041] If it is determined that the CPV valve does not have a stuck normally closed fault, then it is determined that the FTIV valve has a stuck normally closed fault.

[0042] Furthermore, the third diagnosis is conducted using the following method:

[0043] Keep the FTIV valve open and close the CPV valve to reach the fourth time threshold, so that the tank pressure stabilizes at atmospheric pressure.

[0044] If the tank pressure rises above the fifth pressure threshold after the CPV valve is closed, it is determined that the CPV valve is not stuck and normally open. Conversely, if the tank pressure drops instead of rising after the CPV valve is closed, it is suspected that the CPV valve is stuck and normally open. By combining other CPV valve monitoring solutions in the system, the CPV valve stuck and normally open fault can be quickly and finally determined.

[0045] Furthermore, before the fourth diagnosis, it is necessary to determine whether the desorption vacuum conditions are met. If the desorption vacuum conditions are met, the fourth diagnosis is initiated.

[0046] The fourth diagnosis was conducted using the following methods:

[0047] Close the FTIV valve and gradually open the CPV valve;

[0048] If the pressure drop in the oil tank exceeds the sixth pressure threshold, it is determined that the FTIV valve has a stuck normally open fault.

[0049] If the pressure drop in the oil tank is less than the sixth pressure threshold, it is determined that the FTIV valve has no stuck normally open fault.

[0050] To achieve the above objectives, on the other hand, a fault monitoring device for FTIV valves and CPV valves is provided, comprising: a passive fault monitoring module and an active fault monitoring module;

[0051] When the passive fault monitoring enable conditions are met, the passive fault monitoring module activates passive fault monitoring for FTIV valves and CPV valves.

[0052] When the passive fault monitoring enable condition is not met, but the active fault monitoring enable condition is met, the active fault monitoring module will enable active fault monitoring for the FTIV valve and the CPV valve.

[0053] The passive fault monitoring module opens the FTIV valve based on the evaporation system's own control requirements to diagnose whether the FTIV valve has a fault and the type of fault.

[0054] The active fault monitoring module actively opens and closes the FTIV valve and CPV valve in sequence according to diagnostic needs, and diagnoses whether the FTIV valve and CPV valve have faults and the type of fault.

[0055] To achieve the above objectives, another aspect is to provide a storage medium storing several instructions, which a processor loads to execute the above-described fault monitoring method for FTIV valves and CPV valves.

[0056] To achieve the above objectives, on the other hand, a vehicle controller is provided, installed in a hybrid vehicle, the hybrid vehicle including a high-pressure fuel tank, a fuel tank isolation valve and a fuel tank pressure sensor configuration, including the above-mentioned fault monitoring device for the FTIV valve and CPV valve, and / or the above-mentioned storage medium.

[0057] It should be noted that the terms "first," "second," and similar terms used in this article are merely for describing the constituent elements of the technical solution and do not constitute a limitation on the technical solution, nor should they be interpreted as an indication or implication of the importance of the corresponding elements; elements with terms such as "first," "second," or similar terms indicate that at least one of the elements is included in the corresponding technical solution. Attached Figure Description

[0058] To more clearly illustrate the technical solution of the present invention and facilitate a further understanding of its technical effects, features, and objectives, the present invention will be described in detail below with reference to the accompanying drawings. The drawings constitute an essential part of the specification and are used together with Embodiment 1 of the present invention to illustrate the technical solution of the present invention, but do not constitute a limitation on the present invention.

[0059] The same reference numerals in the attached diagrams represent the same parts, specifically:

[0060] Figure 1 A schematic diagram of the configuration structure for a low desorption pipeline.

[0061] Figure 2 This is a schematic diagram of the configuration of two desorption pipelines.

[0062] Figure 3This is a flowchart of Example 1.

[0063] Figure 4 This is a schematic diagram of the passive fault monitoring process in Example 1.

[0064] Figure 5 This is a schematic diagram of the active fault monitoring process in Example 2. Detailed Implementation

[0065] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described below are merely illustrative of the technical solutions of the present invention, and not intended to limit the invention. Furthermore, the parts described in the embodiments or drawings are merely illustrative examples of relevant parts of the present invention, and not the entirety of the invention.

[0066] Example 1:

[0067] The current mainstream desorption pipeline hardware configuration schemes are mainly as follows: Figure 1 and Figure 2 As shown. Figure 1 It has only one low desorption line, which is usually connected to the intake manifold after the throttle body, and is mostly configured for PFI engines. Figure 2 It has two desorption lines: one connected to the intake manifold after the throttle valve (low desorption line), and the other connected to the turbocharger compressor before it, used in conjunction with a venturi to increase desorption flow (high desorption line), mostly found in GDI engines. This embodiment proposes a fault monitoring method for the FTIV valve and CPV valve for these two configurations, such as... Figure 3 As shown, it specifically includes two steps: S1 passive fault monitoring and S2 active fault monitoring. When the passive fault monitoring enable condition is not met, active fault monitoring can be selected to realize fault monitoring of FTIV valve and CPV valve.

[0068] S1 passive fault monitoring, such as Figure 4 As shown, the specific steps are as follows:

[0069] S1-1. Determine whether the passive fault monitoring enable condition is met. If it is met, proceed to step S1-2.

[0070] Specifically, the passive fault monitoring enabling conditions include: when the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold, the carbon canister flushing requirement causes the FTIV valve to open, or when the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold, the refueling requirement causes the FTIV valve to open to release pressure.

[0071] S1-2, Open the FTIV valve

[0072] If the pressure difference before and after the FTIV valve opens is greater than or equal to the second pressure threshold, then the FTIV valve is diagnosed as fault-free.

[0073] If the pressure difference before and after the FTIV valve opens is less than the second pressure threshold, the duration exceeds the first time threshold, and no oil tank pressure signal sticking fault is detected, then the FTIV valve stuck normally closed fault is diagnosed.

[0074] If the pressure difference before and after the FTIV valve opens is less than the second pressure threshold, the duration exceeds the first time threshold, and a viscous fault in the tank pressure signal is detected, then the diagnostic process is exited.

[0075] In step S1, passive monitoring refers to monitoring the FTIV valve's operation without actively intervening for diagnostic needs. Instead, it involves monitoring the FTIV valve based on the evaporation system's own control requirements, such as when the FTIV valve opens for canister flushing or refueling to release pressure. If the tank pressure is relatively high (far from atmospheric pressure) before the system opens the FTIV valve, the pressure change before and after the FTIV valve opens can be used to determine whether the FTIV valve correctly responded to the opening command. If the FTIV valve actually opens, the tank pressure will gradually approach atmospheric pressure. This means the pressure change before and after opening will be significant, exceeding the threshold. In this case, it can be determined that the FTIV valve has neither a stuck normally closed nor a stuck normally open fault. This is because if the FTIV valve remained stuck open, the tank pressure would be the same as atmospheric pressure through the carbon canister, making it impossible to reach the previously relatively high pressure level. Furthermore, even after the system opens it, the pressure will not change significantly due to the continued stuck open state. Conversely, if the FTIV valve does not open, remaining stuck normally closed, the tank pressure will not change significantly. This means the pressure change before and after the system opens the FTIV valve will be small. If the system has kept the FTIV valve open for a considerable period, and the tank pressure change remains small and below the threshold, and the system has not detected any sticky tank pressure signal, then it can be determined that the FTIV valve has a stuck normally closed fault.

[0076] S2 Active Fault Detection, such as Figure 5 As shown, the specific steps are as follows:

[0077] S2-1. Determine whether the active fault monitoring enable condition is met. If it is met, proceed to step S2-2.

[0078] Specifically, the active fault monitoring enabling conditions include: when the absolute value of the fuel tank pressure is greater than or equal to a first pressure threshold, the carbon canister flushing time exceeds a second time threshold, or the carbon canister load is less than a load threshold and the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold, or the engine running time exceeds a third time threshold and the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold.

[0079] S2-2. Open the FTIV valve and complete the first diagnosis of the FTIV valve based on the pressure change.

[0080] In step S2-2, before the first diagnostic opens the FTIV valve, the engine must be run and the carbon canister flush activated to desorb the combustion oil vapors.

[0081] The first diagnosis proceeds as follows:

[0082] S2-21. Calculate the pressure change before and after the FTIV valve is opened.

[0083] S2-22. If the pressure change is greater than or equal to the third pressure threshold, the FTIV valve is considered to be fault-free.

[0084] S2-23. If the pressure change is less than the third pressure threshold, proceed to the second diagnosis.

[0085] S2-3. Keep the FTIV valve open, close the CPV valve, and then gradually open the CPV valve. Based on the pressure changes, complete the second diagnosis of the FTIV and CPV valves.

[0086] Specifically, the steps for the second diagnosis are as follows:

[0087] S2-31. Determine whether the desorption vacuum condition is met. If the desorption vacuum condition is met, proceed to step S2-32.

[0088] Specifically, before the second diagnosis, it is determined whether the desorption vacuum conditions are met. The specific method is as follows:

[0089] If there is only one low desorption line, the desorption vacuum condition is determined based on the low desorption line. If there are two lines, high and low desorption, the desorption vacuum condition is determined by either the low desorption line or the high desorption line.

[0090] The low desorption pipeline determines whether the desorption vacuum condition is met based on the difference between the intake manifold pressure and atmospheric pressure.

[0091] The high desorption pipeline is used to determine whether the desorption vacuum condition is met based on the pressure difference between the high desorption pipeline and atmospheric pressure.

[0092] In step S2-31, the vacuum condition of the high desorption pipeline can be determined by using a pressure sensor installed in the high desorption pipeline or by the difference between the pressure model value and atmospheric pressure. The pressure model is a model established with the help of boost pressure signals, etc.

[0093] S2-32. Keep the FTIV valve open and close the CPV valve to allow the tank pressure to stabilize and return to atmospheric pressure.

[0094] S2-33. Keep the FTIV valve open and gradually open the CPV valve. Calculate the pressure difference across the tank. If the pressure difference across the tank is greater than or equal to the fourth pressure threshold, the FTIV valve is not stuck and normally closed. If the pressure difference across the tank is less than the fourth pressure threshold, the FTIV valve or CPV valve may be stuck and normally closed.

[0095] S2-34. If the FTIV valve or CPV valve may be stuck and normally closed, determine whether the CPV valve or FTIV valve has a stuck and normally closed fault in turn. Specifically, if other CPV valve monitoring schemes in the system have determined that the CPV valve has a stuck and normally closed fault, then exit the diagnostic process; if it is determined that the CPV valve does not have a stuck and normally closed fault, then determine that the FTIV valve has a stuck and normally closed fault.

[0096] S2-34. Keep the FTIV valve open, close the CPV valve, and complete the third diagnostic for the CPV valve.

[0097] The specific steps for the third diagnosis are as follows:

[0098] S2-341. Keep the FTIV valve open and close the CPV valve to reach the fourth time threshold, so that the oil tank pressure stabilizes at atmospheric pressure.

[0099] S2-342. If the tank pressure rises above the fifth pressure threshold after the CPV valve is closed, it is determined that the CPV valve is not stuck and normally open. Conversely, if the tank pressure drops instead of rising after the CPV valve is closed, it is suspected that the CPV valve is stuck and normally open. Combine this with other CPV valve monitoring schemes in the system to quickly and finally determine the CPV valve stuck and normally open fault.

[0100] S2-35. Close the FTIV valve and gradually open the CPV valve to complete the fourth diagnostic test for the FTIV valve.

[0101] Before the fourth diagnosis, it is necessary to determine whether the desorption vacuum conditions are met. If the desorption vacuum conditions are met, the fourth diagnosis is initiated.

[0102] The fourth diagnosis was conducted using the following methods:

[0103] S2-351. Close the FTIV valve and gradually open the CPV valve.

[0104] S2-352. If the oil tank pressure drops below the sixth pressure threshold, it is determined that the FTIV valve has a stuck normally open fault.

[0105] S2-353. If the pressure drop in the oil tank is less than the sixth pressure threshold, then the FTIV valve is determined to be free of jamming and normally open faults.

[0106] In step S2, active monitoring refers to the diagnostic module's active intervention in the control of the FTIV valve. The diagnostic module directly sends commands to control the FTIV valve's on / off state to achieve fault monitoring. If the conditions for active monitoring are met before the conditions for passive monitoring are fulfilled and results are obtained, active monitoring will not be activated again. Considering the impact of active control monitoring on mixture impact, evaporative emissions, etc., certain enabling conditions need to be set, such as the carbon canister flushing being activated and having accumulated a flushing period, the carbon canister load being low, and the engine having been running for a period of time. Because monitoring is based on the fuel tank pressure signal, the current system must be free of fuel tank pressure sensor-related faults, as well as circuit drive stage faults such as those of the CPV valve and FTIV valve.

[0107] Example 2:

[0108] A fault monitoring device for FTIV valves and CPV valves includes: a passive fault monitoring module and an active fault monitoring module;

[0109] When the passive fault monitoring enable conditions are met, the passive fault monitoring module activates passive fault monitoring for FTIV valves and CPV valves.

[0110] When the passive fault monitoring enable condition is not met, but the active fault monitoring enable condition is met, the active fault monitoring module will enable active fault monitoring for the FTIV valve and the CPV valve.

[0111] The passive fault monitoring module opens the FTIV valve based on the evaporation system's own control requirements to diagnose whether the FTIV valve has a fault and the type of fault.

[0112] The active fault monitoring module actively opens and closes the FTIV valve and CPV valve in sequence according to diagnostic needs, and diagnoses whether the FTIV valve and CPV valve have faults and the type of fault.

[0113] It should be noted that the above embodiments are only for more clearly illustrating the technical solution of the present invention. Those skilled in the art will understand that the implementation of the present invention is not limited to the above content. Any obvious changes, substitutions or replacements made based on the above content do not exceed the scope of the technical solution of the present invention. Other implementations will also fall within the scope of the present invention without departing from the concept of the present invention.

Claims

1. A fault monitoring method for FTIV valves and CPV valves, characterized in that, The specific method is as follows: When the passive fault monitoring enable condition is met, passive fault monitoring is activated for the FTIV valve. When the passive fault monitoring enable condition is not met, but the active fault monitoring enable condition is met, active fault monitoring is enabled for FTIV valves and CPV valves. The passive fault monitoring utilizes the evaporation system's own control requirements to open the FTIV valve, diagnosing whether the FTIV valve has a fault and the type of fault. The active fault monitoring actively opens and closes the FTIV valve and CPV valve in sequence according to diagnostic needs, and diagnoses whether the FTIV valve and CPV valve have faults and the type of faults. The passive fault monitoring method is as follows: Open the FTIV valve; If the pressure difference before and after the FTIV valve opens is greater than or equal to the second pressure threshold, then the FTIV valve is diagnosed as fault-free. If the pressure difference before and after the FTIV valve opens is less than the second pressure threshold, the duration exceeds the first time threshold, and no oil tank pressure signal sticking fault is detected, then the FTIV valve stuck normally closed fault is diagnosed. If the pressure difference before and after the FTIV valve opens is less than the second pressure threshold, the duration exceeds the first time threshold, and a viscous fault in the tank pressure signal is detected, then exit the diagnostic process. The active fault monitoring performs the following operations in sequence: Open the FTIV valve and perform the first diagnostic on the FTIV valve based on the pressure change; Keep the FTIV valve open, close the CPV valve, and then gradually open the CPV valve. Based on the pressure changes, complete the second diagnosis of the FTIV and CPV valves. Keep the FTIV valve open, close the CPV valve, and complete the third diagnostic for the CPV valve; Close the FTIV valve and gradually open the CPV valve to complete the fourth diagnostic test of the FTIV valve.

2. The fault monitoring method for FTIV valves and CPV valves as described in claim 1, characterized in that, The passive fault monitoring enabling conditions include: when the absolute value of the tank pressure is greater than or equal to the first pressure threshold, the FTIV valve opens due to the need for carbon canister flushing; or when the absolute value of the tank pressure is greater than or equal to the first pressure threshold, the FTIV valve opens to release pressure due to the need for refueling.

3. The fault monitoring method for FTIV valves and CPV valves as described in claim 1, characterized in that, The active fault monitoring enabling conditions include: when the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold, the carbon canister flushing time exceeds the second time threshold, or the carbon canister load is less than the load threshold and the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold, or the engine running time exceeds the third time threshold and the absolute value of the fuel tank pressure is greater than or equal to the first pressure threshold.

4. The fault monitoring method for FTIV valves and CPV valves as described in claim 1, characterized in that, Before the first diagnostic opens the FTIV valve, the engine must be run and the carbon canister flush activated to desorb combustion oil vapors.

5. The fault monitoring method for FTIV valves and CPV valves as described in claim 4, characterized in that, The specific method for the first diagnosis is as follows: Calculate the pressure change before and after the FTIV valve opens; If the pressure change is greater than or equal to the third pressure threshold, the FTIV valve is considered to be fault-free. If the pressure change is less than the third pressure threshold, then proceed to the second diagnostic step.

6. The fault monitoring method for FTIV valves and CPV valves as described in claim 1, characterized in that, Before the second diagnosis, it is necessary to determine whether the desorption vacuum conditions are met; If the desorption vacuum condition is met, the second diagnosis will begin. If the desorption vacuum condition is not met, return to the active fault monitoring enable condition judgment.

7. The fault monitoring method for FTIV valves and CPV valves as described in claim 6, characterized in that, Before the second diagnosis, determine whether the desorption vacuum conditions are met. The specific method is as follows: If there is only one low desorption line, the desorption vacuum condition is determined based on the low desorption line. If there are two lines, high and low desorption, the desorption vacuum condition is determined by either the low desorption line or the high desorption line. The low desorption pipeline determines whether the desorption vacuum condition is met based on the difference between the intake manifold pressure and atmospheric pressure. The high desorption pipeline is used to determine whether the desorption vacuum condition is met based on the pressure difference between the high desorption pipeline and atmospheric pressure.

8. The fault monitoring method for FTIV valves and CPV valves as described in claim 6, characterized in that, The second diagnosis was conducted using the following methods: Keep the FTIV valve open and close the CPV valve to allow the tank pressure to stabilize and return to atmospheric pressure. Keep the FTIV valve open, gradually open the CPV valve, and calculate the pressure difference across the tank. If the pressure difference across the tank is greater than or equal to the fourth pressure threshold, the FTIV valve is not stuck and normally closed. If the pressure difference across the tank is less than the fourth pressure threshold, the FTIV valve or CPV valve may be stuck and normally closed.

9. The fault monitoring method for FTIV valves and CPV valves as described in claim 8, characterized in that, If the FTIV valve or CPV valve may be stuck and normally closed, check whether the CPV valve or FTIV valve has a stuck and normally closed fault in turn. If other monitoring schemes for CPV valves in the system have determined that the CPV valve has a stuck normally closed fault, then exit the diagnostic process. If it is determined that the CPV valve does not have a stuck normally closed fault, then it is determined that the FTIV valve has a stuck normally closed fault.

10. The fault monitoring method for FTIV valves and CPV valves as described in claim 1, characterized in that, The third diagnosis was conducted using the following method: Keep the FTIV valve open and close the CPV valve to reach the fourth time threshold, so that the tank pressure stabilizes at atmospheric pressure. If the tank pressure rises above the fifth pressure threshold after the CPV valve is closed, it is determined that the CPV valve is not stuck and normally open. Conversely, if the tank pressure drops instead of rising after the CPV valve is closed, it is suspected that the CPV valve is stuck and normally open. By combining other CPV valve monitoring solutions in the system, the CPV valve stuck and normally open fault can be quickly and finally determined.

11. The fault monitoring method for FTIV valves and CPV valves as described in claim 1, characterized in that, Before the fourth diagnosis, it is necessary to determine whether the desorption vacuum conditions are met. If the desorption vacuum conditions are met, the fourth diagnosis is initiated. The fourth diagnosis was conducted using the following methods: Close the FTIV valve and gradually open the CPV valve; If the pressure drop in the oil tank exceeds the sixth pressure threshold, it is determined that the FTIV valve has a stuck normally open fault. If the pressure drop in the oil tank is less than the sixth pressure threshold, it is determined that the FTIV valve has no stuck normally open fault.

12. A fault monitoring device for FTIV valves and CPV valves, employing the fault monitoring method for FTIV valves and CPV valves as described in claim 1, characterized in that, include: Passive fault monitoring module and active fault monitoring module; When the passive fault monitoring enable conditions are met, the passive fault monitoring module activates passive fault monitoring for FTIV valves and CPV valves. When the passive fault monitoring enable condition is not met, but the active fault monitoring enable condition is met, the active fault monitoring module will enable active fault monitoring for the FTIV valve and the CPV valve. The passive fault monitoring module opens the FTIV valve based on the evaporation system's own control requirements to diagnose whether the FTIV valve has a fault and the type of fault. The active fault monitoring module actively opens and closes the FTIV valve and CPV valve in sequence according to diagnostic needs, and diagnoses whether the FTIV valve and CPV valve have faults and the type of fault.

13. A storage medium, characterized in that, The system stores several instructions, and the processor loads the instructions to execute the fault monitoring method for FTIV valves and CPV valves as described in any one of claims 1 to 11.

14. A vehicle controller, installed in a hybrid vehicle, the hybrid vehicle comprising a high-pressure fuel tank, a fuel tank isolation valve, and a fuel tank pressure sensor, characterized in that, Includes the fault monitoring device for FTIV valves and CPV valves as described in claim 12, and / or the storage medium as described in claim 13.

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