CN115853681A

CN115853681A - Desorption system monitoring method, device, equipment and storage medium

Info

Publication number: CN115853681A
Application number: CN202211720182.0A
Authority: CN
Inventors: 张然; 邹洪波
Original assignee: Zhejiang Geely Holding Group Co Ltd; Geely Automobile Research Institute Ningbo Co Ltd
Current assignee: Zhejiang Geely Holding Group Co Ltd; Geely Automobile Research Institute Ningbo Co Ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2023-03-28

Abstract

The disclosure provides a desorption system monitoring method, a desorption system monitoring device, desorption equipment and a storage medium. The method comprises the following steps: determining that the desorption system meets the diagnosis condition, and determining the first time length of the oil tank pressure in a descending state when the desorption system is in a desorption working condition; and then determining the working state of the desorption system according to the first time length, the second time length of the opening state of the carbon tank electromagnetic valve and the control duty ratio of the carbon tank electromagnetic valve. The problem of can't accurately monitor desorption system situation under the condition that does not influence the circumstances of traveling in the oil tank among the prior art is solved to this disclosure, has realized not needing extra initiative control canister solenoid valve operating condition, not influencing under the circumstances of gas mixture control, accurate monitoring fuel evaporation desorption system to can effectively confirm canister solenoid valve's operating condition according to concrete pressure variation condition.

Description

Desorption system monitoring method, device, equipment and storage medium

Technical Field

The present disclosure relates to the field of vehicle technologies, and in particular, to a method, an apparatus, a device, and a storage medium for monitoring a desorption system.

Background

In a vehicle equipped with a gasoline engine, a large amount of oil vapor is filled in a fuel tank due to volatility of gasoline. When the engine runs, oil vapor is generally introduced into an engine intake manifold through a fuel evaporation system consisting of an oil tank, a carbon canister (the carbon canister contains a carbon canister vent valve, a carbon canister electromagnetic valve or equivalent devices such as an air pump and the like), the carbon canister electromagnetic valve, a plurality of pipelines and the like in sequence, and enters an engine cylinder along with intake flow for combustion, so that the fuel economy of a vehicle is improved, and a large amount of oil vapor is prevented from leaking into the atmosphere to pollute the environment. In order to prevent the oil vapor leakage, the oil vapor leakage in the fuel evaporation system needs to be detected in real time so as to be maintained in time.

Wherein, in carrying out real-time detection to the oil vapor leakage among the fuel evaporation system, need carry out flow monitoring to the desorption system among the fuel evaporation system specially to it does not have the structural fault in the desorption system to confirm. The desorption system is used for expressing the part from the carbon canister electromagnetic valve to the engine air inlet pipeline and is used for desorbing the steam adsorbed in the carbon canister into the engine air inlet pipeline to participate in combustion.

The existing desorption system monitoring method is mainly characterized in that whether a desorption system works normally or not is judged through pressure change of a pipeline on one side of an engine, so that the structure in the desorption system needs to be controlled to work actively, and the stability of normal running of a vehicle is influenced.

Disclosure of Invention

The disclosure provides a desorption system monitoring method, a desorption system monitoring device, desorption system monitoring equipment and a storage medium, and aims to solve the problem that the condition of a desorption system cannot be accurately monitored in an oil tank under the condition that driving is not influenced.

In a first aspect, the present disclosure provides a desorption system monitoring method, including:

determining that a desorption system meets diagnosis conditions, wherein the desorption system comprises a high-load desorption pipeline and a low-load desorption pipeline, and the diagnosis conditions comprise diagnosis conditions corresponding to the high-load desorption pipeline and diagnosis conditions corresponding to the low-load desorption pipeline;

if the desorption system is in the desorption working condition, determining the first time length that the pressure of the oil tank is in a descending state;

and determining the working state of the desorption system according to the first time length, the second time length of the carbon tank electromagnetic valve in the opening state and the control duty ratio of the carbon tank electromagnetic valve.

Optionally, the high-load desorption pipeline corresponds to a diagnosis condition, including: the carbon canister electromagnetic valve and the oil tank pressure sensor are not in failure; both the supercharger boost pressure and the intake manifold pressure are above the corresponding limits; the engine load variation and the throttle opening variation are both lower than corresponding limit values; the corresponding diagnosis conditions of the low-load desorption pipeline comprise: the carbon tank electromagnetic valve and the oil tank pressure sensor are not in fault; the pressure of the intake manifold is within a set range; the variation of the engine load and the variation of the throttle opening are both lower than the corresponding limit values.

Optionally, if the desorption system is in the desorption operating mode, determining a first duration that the pressure of the oil tank is in the reduced state includes: determining that a desorption system is in a desorption working condition; determining the oil tank pressure at the current moment and the oil tank pressure at the previous moment; if the pressure of the oil tank at the previous moment is higher than that of the oil tank at the current moment, determining that the pressure of the oil tank is in a descending state, and increasing the time of the timer corresponding to the first time length; and determining the time length of the timer when the duration of the desorption working condition reaches the time length limit value of the desorption working condition as a first time length, wherein the time length limit value of the desorption working condition is a second time length.

Optionally, determining the working state of the desorption system according to the first duration, the second duration when the canister electromagnetic valve is in the open state, and the control duty cycle of the canister electromagnetic valve, includes: determining that the control duty ratio of the carbon tank electromagnetic valve is a constant value when the total desorption working condition time reaches a second time; taking the ratio of the first time length to the second time length as the ratio of the pressure drop time; and determining the working state of the desorption system based on the absolute value of the difference value between the pressure reduction time ratio and the control duty ratio and a set threshold.

Optionally, after determining that the desorption system satisfies the diagnostic condition, the method further includes: if the desorption system is not in the desorption working condition, recording the duration of the desorption working condition and the real-time oil tank pressure; and determining the minimum value of the real-time oil tank pressure when the time length of the non-desorption working condition reaches the corresponding time length threshold value.

Optionally, determining the working state of the desorption system based on the absolute value of the difference between the pressure drop time ratio and the control duty ratio and a set threshold, including: if the absolute value of the difference value is smaller than the set threshold value, determining that the desorption system is in a normal working state; if the absolute value of the difference value is larger than or equal to the set threshold value, determining that the desorption system has an abnormal working condition; and determining the specific type corresponding to the abnormal working condition based on the diagnosis condition type, the minimum value of the real-time oil tank pressure and the set pressure threshold.

Optionally, the determining a specific type corresponding to the abnormal operating condition based on the type of the diagnostic condition, the minimum value of the pressure of the real-time oil tank, and the set pressure threshold includes: if the diagnosis condition type is the diagnosis condition corresponding to the high-load desorption pipeline: if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon tank electromagnetic valve is blocked and normally closed; if the minimum value of the real-time oil tank pressure is lower than a set pressure threshold value, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon tank electromagnetic valve is stuck and normally opened; if the diagnosis condition type is the diagnosis condition corresponding to the low-load desorption pipeline: if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is low-load desorption flow fault and normally closed due to clamping stagnation of the carbon tank electromagnetic valve; and if the minimum value of the real-time oil tank pressure is lower than the set pressure threshold value, determining that the specific type of the abnormal working condition is a low-load desorption flow fault and the carbon canister electromagnetic valve is stuck and normally opened.

Optionally, determining the working state of the desorption system according to the first duration, the second duration when the canister solenoid valve is in the open state, and the control duty ratio of the canister solenoid valve, includes: determining that the control duty ratio of the carbon tank electromagnetic valve is a non-constant value when the total desorption working condition time reaches a second time; and exiting the desorption system working state diagnosis process until the diagnosis condition is met again.

In a second aspect, the present disclosure provides a desorption system monitoring device, which includes:

the diagnosis module is used for determining that the desorption system meets diagnosis conditions, the desorption system comprises a high-load desorption pipeline and a low-load desorption pipeline, and the diagnosis conditions comprise diagnosis conditions corresponding to the high-load desorption pipeline and diagnosis conditions corresponding to the low-load desorption pipeline;

the calculation module is used for determining the first time length of the oil tank pressure in a descending state when the desorption system is in a desorption working condition;

and the determining module is used for determining the working state of the desorption system according to the first time length, the second time length of the opening state of the carbon tank electromagnetic valve and the control duty ratio of the carbon tank electromagnetic valve.

Optionally, the diagnosis module specifically includes that the high-load desorption pipeline corresponds to the diagnosis condition, including: the carbon canister electromagnetic valve and the oil tank pressure sensor are not in failure; the supercharger boost pressure and the intake manifold pressure are both above corresponding limits; the engine load variation and the throttle opening variation are both lower than corresponding limit values; the corresponding diagnosis conditions of the low-load desorption pipeline comprise: the carbon canister electromagnetic valve and the oil tank pressure sensor are not in failure; the pressure of the intake manifold is within a set range; the variation of the engine load and the variation of the throttle opening are both lower than the corresponding limit values.

Optionally, the calculation module is specifically configured to determine that the desorption system is in a desorption condition; determining the oil tank pressure at the current moment and the oil tank pressure at the previous moment; if the pressure of the oil tank at the previous moment is higher than that of the oil tank at the current moment, determining that the pressure of the oil tank is in a descending state, and increasing the time of the timer corresponding to the first time length; and determining the time length of the timer when the duration of the desorption working condition reaches the time length limit value of the desorption working condition as a first time length, wherein the time length limit value of the desorption working condition is a second time length.

Optionally, the determining module is specifically configured to determine that the control duty ratio of the canister solenoid valve is a constant value when the total desorption condition duration reaches the second duration; taking the ratio of the first time length to the second time length as the ratio of the pressure drop time; and determining the working state of the desorption system based on the absolute value of the difference value between the pressure reduction time ratio and the control duty ratio of the carbon tank solenoid valve and a set threshold value.

Optionally, the determining module is further configured to, after determining that the desorption system meets the diagnosis condition, record a duration of the desorption system under the non-desorption condition and a real-time oil tank pressure if the desorption system is not under the desorption condition; and determining the minimum value of the real-time oil tank pressure when the non-desorption working condition time reaches the corresponding time threshold.

Optionally, the determining module is specifically configured to determine that the desorption system is in a normal working state if the absolute value of the difference is smaller than a set threshold; if the absolute value of the difference value is larger than or equal to the set threshold value, determining that the desorption system has an abnormal working condition; and determining the specific type corresponding to the abnormal working condition based on the diagnosis condition type, the minimum value of the real-time oil tank pressure and the set pressure threshold.

Optionally, the determining module is specifically configured to, if the diagnosis condition type is a diagnosis condition corresponding to the high-load desorption pipeline: if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon tank electromagnetic valve is blocked and normally closed; if the minimum value of the real-time oil tank pressure is lower than the set pressure threshold, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon canister electromagnetic valve is stuck and normally opened; if the diagnosis condition type is the diagnosis condition corresponding to the low-load desorption pipeline: if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is low-load desorption flow fault and normally closed due to clamping stagnation of the carbon tank electromagnetic valve; and if the minimum value of the real-time oil tank pressure is lower than the set pressure threshold value, determining that the specific type of the abnormal working condition is a low-load desorption flow fault and the carbon tank electromagnetic valve is stuck and normally opened.

Optionally, the determining module is specifically configured to determine that the control duty ratio of the canister electromagnetic valve is a non-constant value when the total desorption condition duration reaches the second duration; and exiting the desorption system working state diagnosis process until the diagnosis condition is met again.

In a third aspect, the present disclosure also provides a control apparatus comprising:

at least one processor;

and a memory communicatively coupled to the at least one processor;

the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to cause the control device to perform a desorption system monitoring method corresponding to any one of the embodiments of the first aspect of the disclosure.

In a fourth aspect, the present disclosure further provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, the desorption system monitoring method according to any one of the first aspects of the present disclosure is implemented.

According to the desorption system monitoring method, device and equipment and the storage medium, the desorption system is determined to meet the diagnosis condition, and when the desorption system is in the desorption working condition, the first time length that the pressure of the oil tank is in a descending state is determined; and then determining the working state of the desorption system according to the first time length, the second time length of the opening state of the carbon tank electromagnetic valve and the control duty ratio of the carbon tank electromagnetic valve. Therefore, by monitoring the pressure change of the oil tank, the fuel evaporation and desorption system can be accurately monitored under the conditions that the working state of the carbon canister electromagnetic valve does not need to be actively controlled additionally and the control of mixed gas is not influenced, and the working state of the carbon canister electromagnetic valve can be effectively determined according to the specific pressure change condition.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

Fig. 1 is an application scene diagram of a desorption system monitoring method according to an embodiment of the present disclosure;

fig. 2 is a flowchart of a desorption system monitoring method according to an embodiment of the disclosure;

fig. 3a is a flow chart of a desorption system monitoring method according to another embodiment of the present disclosure;

fig. 3b is a flowchart of a method for determining the operating state of the desorption system based on a set threshold provided in the embodiment shown in fig. 3 a;

fig. 4 is a schematic structural diagram of a desorption system monitoring device according to yet another embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a control device according to yet another embodiment of the present disclosure.

With the foregoing drawings in mind, certain embodiments of the disclosure have been shown and described in more detail below. These drawings and written description are not intended to limit the scope of the disclosed concepts in any way, but rather to illustrate the concepts of the disclosure to those skilled in the art by reference to specific embodiments.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The following are descriptions of terms to which the disclosure relates:

a fuel evaporation system: the system composed of the equipment and the components for the existence and the passing of the steam volatilized from the gasoline tank to the intake manifold of the engine sequentially comprises the gasoline tank (or a gasoline tank assembly), a carbon tank (or a carbon tank assembly), a carbon tank ventilation valve (or equivalent devices such as an air pump), a carbon tank electromagnetic valve, a connecting pipeline and the intake manifold of the engine. Wherein, the carbon canister is used for absorbing the steam generated by the volatilization of the gasoline and preventing the steam from being discharged into the air; the carbon canister vent valve is used for sealing a valve of a carbon canister connection port with external air and can be used for monitoring the leakage condition of a fuel evaporation system; the canister solenoid valve is used to control the venting and closing between the canister and the engine.

A desorption system: the desorption system is used for representing the part from the carbon tank electromagnetic valve to the air inlet pipeline of the engine. The system comprises a high-load desorption pipeline and a low-load desorption pipeline, wherein the high-load desorption pipeline is from a carbon canister electromagnetic valve to an engine air inlet pipeline through a Venturi tube, and the low-load desorption pipeline is from the carbon canister electromagnetic valve to an engine air inlet manifold; the former mainly desorbs the steam adsorbed in the carbon canister to the engine air inlet pipeline to participate in combustion when the supercharger of the engine is supercharged, and the latter mainly desorbs the steam adsorbed in the carbon canister to the engine air inlet pipeline to participate in combustion when the supercharger of the engine is not supercharged.

The following describes the technical solutions of the present disclosure and how to solve the above technical problems in detail with specific embodiments. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the present disclosure will be described below with reference to the accompanying drawings.

In a vehicle equipped with a gasoline engine, a fuel evaporation system is filled with a large amount of oil vapor due to volatility of gasoline. In order to prevent the oil vapor leakage, the oil vapor leakage in the fuel evaporation system needs to be detected in real time so as to be maintained in time. During real-time detection of oil vapor leakage in the fuel evaporation system, flow monitoring needs to be specially performed on a desorption system in the fuel evaporation system to determine that no structural fault exists in the desorption system (the desorption system is used for indicating a part from a carbon canister electromagnetic valve to an engine intake manifold and is used for desorbing vapor adsorbed in the carbon canister into an engine intake pipeline to participate in combustion). However, the existing method for determining the operating state of the desorption system usually needs to actively control the opening of the canister solenoid valve, and the pressure change in the intake manifold before and after the canister solenoid valve is opened and closed is used for judgment.

However, the method affects the working state of the canister solenoid valve during the normal movement of the vehicle (because the canister solenoid valve needs to be completely opened and closed, the canister solenoid valve needs to be actively controlled, otherwise, the diagnostic condition cannot be met at all), and when the canister solenoid valve is completely opened and closed, if the gas concentration in the canister is high, the mixed gas fluctuation can be caused in the fuel evaporation system, and meanwhile, the whole vehicle is driven to shake, and the driving safety of the vehicle is affected.

In order to solve the above problem, an embodiment of the present disclosure provides a desorption system monitoring method, which determines an operating state of a desorption system based on a correlation between a change in a fuel tank pressure under a desorption condition and a normal open/close state of a canister solenoid valve, so that the operating state of the desorption system can be effectively determined without adding an additional structure and without affecting a normal driving state of a vehicle.

The following explains an application scenario of the embodiment of the present disclosure:

fig. 1 is an application scene diagram of the desorption system monitoring method provided by the embodiment of the disclosure. As shown in fig. 1, the fuel evaporation system 100 includes a fuel tank 101, a canister 102, a canister vent valve 103, and a canister solenoid valve 104, which are connected in this order, and a vent shutoff valve 105 is provided at a port of the fuel tank, and a pressure sensor 106 is provided in the fuel tank or at a connection portion between the fuel tank and the canister.

The canister solenoid valve 104 is connected to an intake manifold 111 of the engine 110 through a check valve and a first part connecting line 107, and is further connected to a venturi 112 of the engine 110 through a check valve and a second part connecting line 108, the venturi 112 is connected to the intake manifold 111, and a part from the canister solenoid valve 104 to the intake manifold 111 and the venturi 112 is a desorption system (as shown in 120 in the figure), in a desorption system diagnosis process, oil vapor in the fuel evaporation system 100 enters the engine 110 through the desorption system in a state that the canister solenoid valve 104 normally works, and a pressure sensor 106 detects a pressure change condition in the process, so that the working state of the desorption system can be judged.

It should be noted that, in the scenario shown in fig. 1, only one pressure sensor is illustrated as an example, but the disclosure is not limited thereto, that is, the number of pressure sensors may be any.

The following describes the desorption system monitoring method provided by the present disclosure in detail by specific examples. It should be noted that the following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

Fig. 2 is a flowchart of a desorption system monitoring method according to an embodiment of the present disclosure. As shown in fig. 2, the method comprises the following steps:

and step S201, determining that the desorption system meets the diagnosis condition.

The desorption system comprises a high-load desorption pipeline and a low-load desorption pipeline, and the diagnosis conditions comprise diagnosis conditions corresponding to the high-load desorption pipeline and diagnosis conditions corresponding to the low-load desorption pipeline.

Specifically, the leakage detection of the fuel evaporation system is generally performed in the running process of an automobile or in the working state of an engine, at the moment, the engine can work, the oil vapor in the fuel evaporation system can be sucked in through an intake manifold of the engine, and then the leakage detection is performed through a vacuum method of the intake manifold of the engine. The desorption system detection is also a detection performed when the engine is working.

Before the desorption system detects, it is required to determine that the current working condition meets the diagnosis condition, for example, structures such as a carbon canister electromagnetic valve and an oil tank pressure sensor can work normally, and the pressure of each part meets a set value, so that the gas in the fuel evaporation system can normally pass through the desorption system, and the detection result of the oil tank pressure sensor can be ensured to be correct, so that the working state of the desorption system can be accurately determined.

Because the high-load desorption pipeline and the low-load desorption pipeline in the desorption system are respectively under the non-supercharging condition and the supercharging condition of the supercharger, corresponding diagnosis conditions need to be determined according to the high-load desorption pipeline and the low-load desorption pipeline, and the difference is mainly the working condition of the supercharger and the corresponding pressure change in the intake manifold (when the high-load desorption pipeline works, the pressure in the intake manifold can be higher due to the effect of the supercharger).

After the diagnosis condition met by the desorption system is determined, the corresponding part of the desorption pipeline can be subjected to diagnosis process according to the type of the met diagnosis condition.

Step S202, if the desorption system is in the desorption working condition, determining the first time length of the oil tank pressure in the descending state.

Specifically, when desorption system was in the desorption operating mode, there was gaseous state when flowing through desorption system arrival engine from the charcoal jar promptly, the charcoal jar solenoid valve can be in the open mode this moment. The carbon canister electromagnetic valve is also closed and opened periodically according to a certain frequency in an opening state to control the flow of gas (or gas-liquid mixture) entering the engine, so that the pressure between the fuel evaporation system and the engine is kept in a relatively balanced state. When the canister electromagnetic valve is in an open state, gas in the oil tank can sequentially enter the engine through the canister and the desorption system under the action of vacuum degree, so that the gas pressure in the oil tank can be in a continuous descending process, and can be in a rising process after the canister electromagnetic valve is closed.

Therefore, whether the desorption system is in a normal working state or not can be determined by counting the ratio of the time length (namely the first time length) of the oil tank pressure in the descending state to the time length of the desorption working condition and comparing the ratio with the control duty ratio (namely the ratio of the actual opening time to the whole opening time length) of the canister electromagnetic valve in the opening state.

The statistical method of the first duration can directly acquire the pressure change of the oil tank at continuous moments, and takes the partial duration of pressure reduction as the first duration.

And S203, determining the working state of the desorption system according to the first time length, the second time length of the opening state of the carbon canister electromagnetic valve and the control duty ratio of the carbon canister electromagnetic valve.

Specifically, the second duration is the duration of the desorption condition, and therefore, by comparing the relationship between the ratio of the first duration to the second duration and the control duty ratio, it can be determined whether the canister solenoid valve is in the open state, the pressure of the oil tank is synchronously reduced, if the pressure of the oil tank is synchronously reduced, the desorption system normally works, and if the ratio of the first duration to the second duration of the pressure reduction of the oil tank is smaller than the control duty ratio, a failure of the canister solenoid valve (which may be a failure in the diagnostic process) may exist, or a change (such as a change) of the working state of the canister solenoid valve may occur, and therefore, by comparing the first duration, the second duration and the control duty ratio, the working state of the desorption system can be quickly determined.

According to the desorption system monitoring method provided by the embodiment of the disclosure, the first time length that the pressure of the oil tank is in a descending state is determined when the desorption system is in a desorption working condition by determining that the desorption system meets the diagnosis condition; and then determining the working state of the desorption system according to the first time length, the second time length of the opening state of the carbon canister electromagnetic valve and the control duty ratio. Therefore, by monitoring the pressure change of the oil tank, the fuel evaporation and desorption system can be accurately monitored under the conditions that the working state of the carbon tank electromagnetic valve does not need to be additionally and actively controlled and the control of mixed gas is not influenced, and the working state of the carbon tank electromagnetic valve can be effectively determined according to the specific pressure change condition.

Fig. 3a is a flowchart of a desorption system monitoring method provided by the present disclosure. As shown in fig. 3a, the desorption system monitoring method provided in this embodiment includes the following steps:

and S301, determining that the desorption system meets the diagnosis condition.

Specifically, the state of the desorption system may satisfy any one of the diagnosis conditions of the high-load desorption pipeline and the low-load desorption pipeline, or both of the diagnosis conditions may not be satisfied, and therefore, it is necessary to determine whether the current state of the desorption system satisfies any one of the diagnosis conditions.

Further, specific diagnostic conditions include the following two:

wherein, the high load desorption pipeline corresponds to diagnosis conditions, including: the carbon canister electromagnetic valve and the oil tank pressure sensor are not in failure; the supercharger boost pressure and the intake manifold pressure are both above corresponding limits; the variation of the engine load and the variation of the throttle opening are both lower than the corresponding limit values.

The corresponding diagnosis conditions of the low-load desorption pipeline comprise: the carbon canister electromagnetic valve and the oil tank pressure sensor are not in failure; the pressure of the intake manifold is within a set range; the variation of the engine load and the variation of the throttle opening are both lower than the corresponding limit values.

Specifically, whether a high-load desorption pipeline or a low-load desorption pipeline is adopted, the canister solenoid valve and the oil tank pressure sensor are required to be in normal states, because the canister solenoid valve is required to be switched between an open state and a closed state in the diagnosis process (switched according to actual working requirements rather than according to diagnosis requirements), and meanwhile, the oil tank pressure sensor is required to detect the change of the oil tank pressure, so that the validity of the detection result is ensured.

Meanwhile, the load variation of the engine and the opening variation of the throttle valve are ensured to be in a normal state, namely the engine is ensured to be in a normal working state, so that desorbed gas is ensured to normally enter the engine, and the desorption working condition is ensured to be normally carried out.

The high-load desorption pipeline and the low-load desorption pipeline are mainly distinguished whether the supercharger is in a supercharging working condition or not, so that diagnosis conditions corresponding to the high-load desorption pipeline and the low-load desorption pipeline can be distinguished according to the supercharging working condition of the supercharger and the corresponding pressure of the intake manifold.

And step S302, determining that the desorption system is in a desorption working condition.

Specifically, the desorption condition refers to a condition when gas flows from the canister to the engine through the desorption system, and according to the working state of the engine and the working state of the vehicle, the situation that no gas enters the engine may occur, such as the condition when the vehicle stops at an intersection, at the moment, the engine is not turned off, but no gas may pass through the desorption system.

Under the desorption operating mode, the charcoal jar solenoid valve can be in the open mode, and when truning into the desorption operating mode by non-desorption operating mode promptly, the charcoal jar solenoid valve can have the closed condition to trun into the open mode, consequently, the length of time of desorption operating mode can be expressed when being in the length of time of opening with the charcoal jar solenoid valve.

And step S303, determining the tank pressure at the current moment and the tank pressure at the previous moment.

Specifically, the pressure in the oil tank under the desorption working condition can be obtained in real time through the oil tank sensor so as to determine whether the pressure of the oil tank is in a descending state.

And S304, if the pressure of the oil tank at the previous moment is higher than that of the oil tank at the current moment, determining that the pressure of the oil tank is in a descending state, and increasing the time of the timer corresponding to the first time length.

Specifically, the first time length corresponding timer is used for recording the total time length of the oil tank pressure in the descending process under the desorption working condition of the current diagnosis process, rather than the time length of single descending.

And S305, determining the time length of the timer when the desorption working condition duration reaches the desorption working condition time length limit value as a first time length.

And the desorption working condition time limit value is the second time.

Specifically, the desorption working condition duration limit is used for corresponding to the total duration of the desorption working condition in the current diagnosis process, and the duty ratio of the canister solenoid valve is easy to change after the desorption working condition duration limit is usually exceeded, so that the duration of the desorption working condition in the diagnosis process needs to be controlled, and diagnosis failure caused by the fact that the duty ratio of the canister solenoid valve is changed in subsequent diagnosis is avoided.

Because the desorption working condition time length limit value is fixed, the first time length in the desorption working condition time length limit value can contain the time lengths of a plurality of complete oil tank pressure reduction processes and the time lengths of incomplete oil tank pressure reduction processes, and subsequent calculation is not influenced.

Because the duration of the desorption working condition is the same as the duration of the opening state of the carbon canister electromagnetic valve, the duration limit value of the desorption working condition is equal to the duration of the opening state of the carbon canister electromagnetic valve, namely the second duration, and therefore the duration limit value of the desorption working condition can be directly represented by the second duration to perform subsequent calculation.

And S306, if the desorption system is not in the desorption working condition, recording the duration of the desorption working condition and the real-time oil tank pressure.

Specifically, the pressure in the fuel tank is usually near atmospheric pressure (because the canister vent valve is in an open state at this time, the fuel evaporation system is the same as the atmosphere), and at this time, the fuel tank pressure does not have a negative value (because the canister solenoid valve is in a normal closed state, the fuel evaporation system does not have a vacuum source). However, if the carbon canister electromagnetic valve has a stuck normally-open fault, a vacuum source exists in the fuel evaporation system, and the real-time pressure of the fuel tank at the moment is obviously lower than the atmospheric pressure, so that whether a desorption fault exists or not and whether the fault is caused by the stuck normally-open fault of the carbon canister electromagnetic valve or the stuck normally-closed fault (the stuck normally-closed fault needs to be judged according to the pressure reduction time and the proportion of the fuel tank pressure in the subsequent desorption working condition) can be judged in an auxiliary manner according to the pressure condition of the fuel tank under the non-desorption working condition.

And S307, determining the minimum value of the real-time oil tank pressure when the time length of the non-desorption working condition reaches the corresponding time length threshold value.

Specifically, the corresponding time length threshold is a time length threshold of the oil tank pressure under the non-desorption working condition in the monitoring and diagnosing process, and the change (including the maximum value and the minimum value) of the oil tank pressure within a certain time length can be determined through the corresponding time length threshold.

The corresponding duration threshold is usually much less than the second duration, because the corresponding duration threshold only needs to ensure that the change in the tank pressure within a certain duration can be monitored, and the tank pressure data for an excessively long time does not need to be acquired.

In some embodiments, if the time length of the non-desorption working condition does not reach the corresponding time length threshold value, the desorption system enters the desorption working condition, and the minimum value of the real-time oil tank pressure from the beginning of the diagnosis process to the beginning of the desorption working condition is obtained.

Steps S306 to S307 are optional steps parallel to steps S302 to S305, and when any condition in step S306 or step S302 is satisfied, the corresponding optional step can be executed; after the step S307 is completed, if the condition of the step S302 is satisfied, the step S302 and the corresponding subsequent steps can be switched to.

And S308, determining that the total duration of the desorption working condition reaches the second duration, and controlling the duty ratio of the carbon tank electromagnetic valve to be a constant value.

Specifically, after the control duty ratio corresponding to the canister solenoid valve is changed, the trend of the pressure decrease of the oil tank is changed accordingly, so that the subsequent calculation becomes complex, and the calculation accuracy cannot be ensured.

Therefore, the control duty ratio of the canister solenoid valve in the second time period needs to be determined to be a fixed value, so that the operating state of the desorption system is determined by comparing the ratio of the first time period to the second time period and the relationship of the control duty ratio.

And step S309, taking the ratio of the first time length to the second time length as the pressure reduction time ratio.

Specifically, because the pressure drop of the oil tank lags behind the opening of the canister solenoid valve, in the second time period, the first time period corresponding to the pressure drop of the oil tank and the total time period of the opening of the canister solenoid valve are not likely to be equal (for example, when the second time period is reached, the canister solenoid valve is opened, the pressure of the oil tank does not drop yet at this time, the first time period is smaller than the total time period of the opening of the canister solenoid valve), and therefore the first time period and the total time period of the opening of the canister solenoid valve cannot be directly compared, so that the ratio of the first time period to the second time period is used, the pressure drop time ratio is obtained, and the pressure drop time ratio is compared with the duty ratio of the canister solenoid valve, so that the result error caused when the first time period and the total time period of the opening of the canister solenoid valve are compared is avoided.

And S310, determining the working state of the desorption system based on the absolute value of the difference value between the pressure reduction time ratio and the control duty ratio and a set threshold.

Specifically, the second time length intercepted actually corresponds to the working conditions of the desorption systems of different vehicles, the specific numerical values of the second time length intercepted actually may be different, and the pressure reduction time ratio and the control duty ratio may have different conditions, that is, the pressure reduction time ratio may be smaller than the control duty ratio of the canister solenoid valve or may be larger than the control duty ratio of the canister solenoid valve, so that the absolute value of the difference value is obtained to compare the relation between the pressure reduction time length and the total opening time length of the canister solenoid valve. If the absolute value is larger than the set threshold, the desorption system usually has an abnormal working condition, and further judgment is needed.

As shown in fig. 3b, it is a flowchart of a method for determining the operating state of the desorption system based on the set threshold, and it includes the following steps:

step S3101, if the absolute value of the difference is smaller than the set threshold, it is determined that the desorption system is in a normal working state.

Specifically, if the absolute value is smaller than the set threshold, it indicates that the ratio of the time length of the pressure drop is approximately the same as the control duty ratio of the canister solenoid valve, which also corresponds to the expected state, and therefore, it can be determined that the desorption system is in the normal operating state.

And step S3102, if the absolute value of the difference value is greater than or equal to the set threshold value, determining that the desorption system has an abnormal working condition.

Specifically, if the absolute value exceeds the set threshold, it indicates that the ratio of the pressure drop time length is deviated from the control duty ratio of the canister solenoid valve, and the pressure drop time may be far shorter than the total opening time of the canister solenoid valve, which may be caused by the canister solenoid valve being stuck and normally closed, or the pressure drop time may be far longer than the total opening time of the canister solenoid valve, which may be caused by the canister solenoid valve being stuck and normally open. Therefore, further judgment is required.

And S3103, determining the specific type corresponding to the abnormal working condition based on the diagnosis condition type, the minimum value of the real-time oil tank pressure and the set pressure threshold value.

Specifically, since the satisfied diagnosis conditions correspond to the high-load desorption line and the low-load desorption line, respectively, when there is an abnormality, there is a difference between the corresponding abnormal desorption lines.

Specific exception types include the following:

if the diagnosis condition type is the diagnosis condition corresponding to the high-load desorption pipeline:

in case one (not shown), if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, the specific type of the abnormal working condition is determined to be high-load desorption flow fault and normally closed due to clamping stagnation of the carbon canister electromagnetic valve.

And under the second condition (not shown), if the minimum value of the pressure of the real-time oil tank is lower than the set pressure threshold value, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon canister electromagnetic valve is stuck and normally opened.

If the diagnosis condition type is the diagnosis condition corresponding to the low-load desorption pipeline:

and in the third case (not shown), if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is low-load desorption flow fault and the carbon canister electromagnetic valve is blocked and normally closed.

And in case IV (not shown), if the minimum value of the pressure of the real-time oil tank is lower than the set pressure threshold value, determining that the specific type of the abnormal working condition is a low-load desorption flow fault and the carbon canister electromagnetic valve is stuck and normally opened.

In particular, the relationship between the real-time minimum tank pressure and the type of canister solenoid valve failure can be found in the foregoing analysis. The type of the abnormal working condition is required to distinguish which part of the desorption pipeline and corresponding flow rate are abnormal, and the specific fault type of the carbon canister electromagnetic valve is convenient for subsequent targeted recording and processing.

And step S311, determining that the total desorption working condition time reaches a second desorption working condition time, and controlling the duty ratio of the carbon tank electromagnetic valve to be a non-constant value.

Specifically, if the control duty ratio of the canister solenoid valve changes within the second time period, if the vehicle running state changes significantly (for example, the vehicle runs from a forward running state to a reverse running state), the time period corresponding to the time period when the pressure of the oil tank is reduced also changes because the time period of each opening of the canister solenoid valve is not fixed, and the working condition of the desorption system cannot be determined effectively at this time.

And S312, exiting the desorption system working state diagnosis process until the diagnosis condition is met again.

Specifically, when the duty ratio of the canister solenoid valve changes, the data acquired in the whole diagnosis process cannot be used, and therefore, the diagnosis process can only be exited until the next diagnosis is performed.

Steps S311 to S312 are optional steps parallel to steps S308 to S310, and when the condition of any step in step S308 or step S311 is satisfied, the optional steps subsequent to the corresponding step can be executed.

According to the desorption system monitoring method provided by the embodiment of the disclosure, after the desorption system meets the diagnosis condition, the specific working state of the desorption system can be determined according to whether the desorption system is in the desorption working condition, the minimum value of the pressure of the oil tank under the non-desorption working condition, the difference value between the ratio of the pressure reduction time of the oil tank under the desorption working condition and the control duty ratio of the carbon canister solenoid valve and the corresponding threshold value, and the specific type corresponding to the abnormal working condition is determined when the abnormality exists. From this, can diagnose different desorption pipelines according to the operating mode that desorption system is actually in under the condition that does not influence canister solenoid valve normal operating condition, need not with other diagnostic process couplings, the independence is strong, can confirm the trouble in the desorption system fast to effective specific type that unusual operating mode corresponds appears in the affirmation, greatly promote desorption system's security.

Fig. 4 is a schematic structural diagram of a desorption system monitoring device provided by the present disclosure. As shown in fig. 4, the desorption system monitoring apparatus 400 includes: a diagnostic module 410, a calculation module 420, and a determination module 430.

Wherein:

the diagnosis module 410 is configured to determine that a desorption system meets a diagnosis condition, where the desorption system includes a high-load desorption pipeline and a low-load desorption pipeline, and the diagnosis condition includes a diagnosis condition corresponding to the high-load desorption pipeline and a diagnosis condition corresponding to the low-load desorption pipeline;

the calculation module 420 is configured to determine a first duration that the pressure of the oil tank is in a decreased state when the desorption system is in a desorption condition;

the determining module 430 is configured to determine the operating state of the desorption system according to the first duration, the second duration when the canister solenoid valve is in the open state, and the control duty ratio of the canister solenoid valve.

Optionally, the diagnosis module 410 specifically includes that the high-load desorption pipeline corresponds to the diagnosis condition, which includes: the carbon canister electromagnetic valve and the oil tank pressure sensor are not in failure; the supercharger boost pressure and the intake manifold pressure are both above corresponding limits; the variation of the engine load and the variation of the throttle opening are lower than corresponding limit values; the corresponding diagnosis conditions of the low-load desorption pipeline comprise: the carbon tank electromagnetic valve and the oil tank pressure sensor are not in fault; the pressure of the intake manifold is within a set range; the variation of the engine load and the variation of the throttle opening are both lower than the corresponding limit values.

Optionally, the calculation module 420 is specifically configured to determine that the desorption system is in a desorption condition; determining the oil tank pressure at the current moment and the oil tank pressure at the previous moment; if the pressure of the oil tank at the previous moment is higher than that of the oil tank at the current moment, determining that the pressure of the oil tank is in a descending state, and increasing the time of the timer corresponding to the first time length; and determining the time length of the timer when the desorption working condition duration reaches the desorption working condition time length limit as a first time length, wherein the desorption working condition time length limit is a second time length.

Optionally, the determining module 430 is specifically configured to determine that the control duty ratio of the canister solenoid valve is a constant value when the total desorption condition duration reaches the second duration; taking the ratio of the first time length to the second time length as the ratio of the pressure drop time; and determining the working state of the desorption system based on the absolute value of the difference value between the pressure reduction time ratio and the control duty ratio of the carbon tank solenoid valve and a set threshold value.

Optionally, the determining module 430 is further configured to, after determining that the desorption system meets the diagnostic condition, if the desorption system is not in the desorption condition, record a duration of the desorption condition and a real-time oil tank pressure; and determining the minimum value of the real-time oil tank pressure when the time length of the non-desorption working condition reaches the corresponding time length threshold value.

Optionally, the determining module 430 is specifically configured to determine that the desorption system is in a normal working state if the absolute value of the difference is smaller than the set threshold; if the absolute value of the difference value is larger than or equal to the set threshold value, determining that the desorption system has an abnormal working condition; and determining the specific type corresponding to the abnormal working condition based on the diagnosis condition type, the minimum value of the real-time oil tank pressure and the set pressure threshold.

Optionally, the determining module 430 is specifically configured to, if the diagnosis condition type is a diagnosis condition corresponding to the high-load desorption pipeline: if the minimum value of the real-time oil tank pressure is higher than a set pressure threshold value, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon tank electromagnetic valve is blocked and normally closed; if the minimum value of the real-time oil tank pressure is lower than the set pressure threshold, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon canister electromagnetic valve is stuck and normally opened; if the diagnosis condition type is the diagnosis condition corresponding to the low-load desorption pipeline: if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is low-load desorption flow fault and normally closed due to clamping stagnation of the carbon tank electromagnetic valve; and if the minimum value of the real-time oil tank pressure is lower than the set pressure threshold value, determining that the specific type of the abnormal working condition is a low-load desorption flow fault and the carbon tank electromagnetic valve is stuck and normally opened.

Optionally, the determining module 430 is specifically configured to determine that the control duty ratio of the canister solenoid valve is a non-constant value when the total desorption condition duration reaches the second duration; and exiting the desorption system working state diagnosis process until the diagnosis condition is met again.

In this embodiment, desorption system monitoring devices can be through monitoring the change of oil tank pressure through the combination of each module, need not additionally active control charcoal jar solenoid valve operating condition, not influence under the circumstances of gas mixture control, and accurate monitoring fuel evaporation desorption system solves the problem that can't accurately monitor desorption system situation under the circumstances that does not influence going in the oil tank.

Fig. 5 is a schematic structural diagram of a control device provided in the present disclosure, and as shown in fig. 5, the control device 500 includes: a memory 510 and a processor 520.

Wherein the memory 510 stores computer programs that are executable by the at least one processor 520. The computer program is executed by the at least one processor 520 to cause the control apparatus to implement the desorption system monitoring method as provided in any of the embodiments above.

Wherein the memory 510 and the processor 520 may be connected by a bus 530.

The related description may be understood by referring to the related description and effects corresponding to the method embodiments, which are not repeated herein.

One embodiment of the present disclosure provides a computer-readable storage medium on which a computer program is stored, the computer program being executed by a processor to implement the desorption system monitoring method according to any of the embodiments corresponding to fig. 2 to 3 b.

The computer readable storage medium may be, among others, ROM, random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like.

An embodiment of the present disclosure provides a computer program product, which contains computer executable instructions, when executed by a processor, for implementing the desorption system monitoring method according to any of the embodiments corresponding to fig. 2 to 3 b.

In the several embodiments provided in the present disclosure, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, a division of modules is merely a division of logical functions, and an actual implementation may have another division, for example, a plurality of modules or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or modules, and may be in an electrical, mechanical or other form.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A desorption system monitoring method, the method comprising:

determining that the desorption system meets diagnosis conditions, wherein the desorption system comprises a high-load desorption pipeline and a low-load desorption pipeline, and the diagnosis conditions comprise diagnosis conditions corresponding to the high-load desorption pipeline and diagnosis conditions corresponding to the low-load desorption pipeline;

if the desorption system is in a desorption working condition, determining a first time length that the pressure of the oil tank is in a descending state;

and determining the working state of the desorption system according to the first time length, the second time length of the opening state of the carbon tank electromagnetic valve and the control duty ratio of the carbon tank electromagnetic valve.

2. The desorption system monitoring method of claim 1, wherein the high-load desorption line corresponds to a diagnostic condition comprising:

the carbon canister electromagnetic valve and the oil tank pressure sensor are not in failure;

the supercharger boost pressure and the intake manifold pressure are both above corresponding limits;

the engine load variation and the throttle opening variation are both lower than corresponding limit values;

the low-load desorption pipeline corresponds to diagnosis conditions and comprises the following steps:

the pressure of the intake manifold is within a set range;

the variation of the engine load and the variation of the throttle opening are both lower than the corresponding limit values.

3. The desorption system monitoring method of claim 1, wherein the determining the first duration of the drop in the tank pressure if the desorption system is in the desorption condition comprises:

determining that the desorption system is in a desorption working condition;

determining the oil tank pressure at the current moment and the oil tank pressure at the previous moment;

if the pressure of the oil tank at the previous moment is higher than that of the oil tank at the current moment, determining that the pressure of the oil tank is in a descending state, and increasing the time of the timer corresponding to the first time length;

and determining the time length of the timer when the desorption working condition duration reaches the desorption working condition time length limit as a first time length, wherein the desorption working condition time length limit is a second time length.

4. The desorption system monitoring method according to any one of claims 1 to 3, wherein determining the operating state of the desorption system according to the first time period, the second time period in which the canister solenoid valve is in the open state and the control duty ratio of the canister solenoid valve comprises:

determining that the control duty ratio of the carbon tank electromagnetic valve is a constant value when the total desorption working condition duration reaches a second duration;

taking the ratio of the first time length to the second time length as a pressure drop time ratio;

and determining the working state of the desorption system based on the absolute value of the difference value between the pressure reduction time ratio and the control duty ratio and a set threshold.

5. The desorption system monitoring method of claim 4, wherein after determining that the desorption system satisfies the diagnostic condition, further comprising:

if the desorption system is not in the desorption working condition, recording the duration of the non-desorption working condition and the real-time oil tank pressure;

and determining the minimum value of the real-time oil tank pressure when the non-desorption working condition time reaches the corresponding time threshold.

6. The desorption system monitoring method according to claim 5, wherein the determining the operating state of the desorption system based on the absolute value of the difference between the pressure drop time ratio and the control duty ratio and a set threshold value comprises:

if the absolute value of the difference value is smaller than the set threshold value, determining that the desorption system is in a normal working state;

if the absolute value of the difference value is larger than or equal to the set threshold value, determining that the desorption system has an abnormal working condition;

and determining the specific type corresponding to the abnormal working condition based on the diagnosis condition type, the minimum value of the real-time oil tank pressure and the set pressure threshold.

7. The desorption system monitoring method of claim 6, wherein the determining the specific type corresponding to the abnormal operating condition based on the diagnostic condition type, the minimum value of the real-time fuel tank pressure and the set pressure threshold value comprises:

if the diagnosis condition type is a diagnosis condition corresponding to the high-load desorption pipeline:

if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon canister electromagnetic valve is clamped, blocked and normally closed;

if the minimum value of the real-time oil tank pressure is lower than the set pressure threshold value, determining that the specific type of the abnormal working condition is a high-load desorption flow fault and the carbon tank electromagnetic valve is stuck to be normally opened;

if the minimum value of the real-time oil tank pressure is higher than the set pressure threshold value, determining that the specific type of the abnormal working condition is low-load desorption flow fault and normally closed due to clamping stagnation of a carbon tank electromagnetic valve;

and if the minimum value of the real-time oil tank pressure is lower than the set pressure threshold value, determining that the specific type of the abnormal working condition is a low-load desorption flow fault and the carbon tank electromagnetic valve is stuck and normally opened.

8. The desorption system monitoring method according to any one of claims 1 to 3, wherein determining the operating state of the desorption system according to the first time period, the second time period in which the canister solenoid valve is in the open state and the control duty ratio of the canister solenoid valve comprises:

determining that the control duty ratio of the carbon tank electromagnetic valve is a non-constant value when the total desorption working condition duration reaches a second duration;

and exiting the desorption system working state diagnosis process until the diagnosis condition is met again.

9. A desorption system monitoring device, comprising:

the calculation module is used for determining the first time length of the pressure of the oil tank in a descending state when the desorption system is in a desorption working condition;

10. A control apparatus, characterized by comprising:

at least one processor;

and a memory communicatively coupled to the at least one processor;

wherein the memory stores instructions executable by the at least one processor to cause the control apparatus to perform a desorption system monitoring method according to any one of claims 1 to 8.

11. A computer-readable storage medium having computer-executable instructions stored thereon, which when executed by a processor, are configured to implement the desorption system monitoring method of any one of claims 1 to 8.