CN114251199A

CN114251199A - Carbon tank desorption pipeline diagnosis method, controller and engine

Info

Publication number: CN114251199A
Application number: CN202011027340.5A
Authority: CN
Inventors: 战金程
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2022-03-29
Anticipated expiration: 2040-09-25
Also published as: CN114251199B

Abstract

The invention relates to the technical field of engines, and provides a carbon tank desorption pipeline diagnosis method, a controller and an engine. The invention discloses a carbon tank desorption pipeline diagnosis method, which is applied to a vehicle evaporation system, wherein the vehicle evaporation system comprises an electromagnetic valve of a carbon tank, and a leakage diagnosis part and a desorption pipeline diagnosis part which are communicated through the electromagnetic valve, and the method comprises the following steps: judging whether pressure difference exists between two ends of the electromagnetic valve when the electromagnetic valve is in a working state; acquiring a solenoid valve driving signal and a tank pressure signal from the leakage diagnosing section in a case where there is a pressure difference across the solenoid valve; and comparing the driving period of the electromagnetic valve driving signal with the fluctuation period of the oil tank pressure signal in the same set time period, and judging whether the desorption pipeline has faults or not according to the comparison result. The carbon tank desorption pipeline diagnosis method provided by the invention realizes carbon tank desorption pipeline diagnosis by using a software strategy, and remarkably reduces the diagnosis cost.

Description

Carbon tank desorption pipeline diagnosis method, controller and engine

Technical Field

The invention relates to the technical field of engines, in particular to a carbon tank desorption pipeline diagnosis method, a controller and an engine.

Background

For a whole gasoline vehicle, a carbon tank and a desorption pipeline thereof are important sources of volatile organic gas, and can pollute the environment. In contrast, the national emission regulations are upgraded to the sixth stage of the country, and more requirements for diagnosis of the desorption pipeline are provided, so that a fault code can be reported or a fault lamp can be lightened when the desorption pipeline is abnormal, so that a customer is prompted to maintain, and the purpose of protecting the environment is achieved.

In view of the above, the main canister desorption pipeline diagnosis scheme in the prior art is to add a pressure sensor between the venturi structure and the canister solenoid valve to diagnose whether the pipeline is faulty, but such a scheme has at least the following defects:

1) a pressure sensor of a desorption pipeline and a related wiring harness are additionally added, so that the cost of the whole vehicle is increased;

2) the device is only suitable for desorption pipelines with Venturi structures and has low applicability;

3) in the diagnosis process, the ventilation stop valve of the carbon tank needs to be closed, so that the volatilization speed of oil vapor in the oil tank is increased, and the environment protection is not facilitated.

Therefore, the invention provides a novel carbon tank desorption pipeline diagnosis scheme.

Disclosure of Invention

In view of the above, the present invention is directed to a method for diagnosing a canister desorption pipeline, a controller and an engine, so as to at least partially solve the above technical problems.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a carbon tank desorption pipeline diagnosis method is applied to a vehicle evaporation system, the vehicle evaporation system comprises an electromagnetic valve of a carbon tank, and a leakage diagnosis part and a desorption pipeline diagnosis part which are communicated through the electromagnetic valve, and the carbon tank desorption pipeline diagnosis method comprises the following steps: judging whether pressure difference exists between two ends of the electromagnetic valve when the electromagnetic valve is in a working state; acquiring a solenoid valve driving signal and a tank pressure signal from the leakage diagnosis section under the condition that a pressure difference exists between two ends of the solenoid valve; and comparing the driving period of the electromagnetic valve driving signal with the fluctuation period of the oil tank pressure signal in the same set time period, and judging whether the desorption pipeline has faults or not according to the comparison result.

Further, the desorption pipeline diagnosis part comprises a low-load desorption pipeline leading to an air intake manifold of the engine and/or a high-load desorption pipeline leading to a pipeline at the rear end of the air filter.

And, the determining whether a pressure difference exists across the solenoid valve comprises: acquiring the pressure of an air inlet manifold of the low-load desorption pipeline and the environmental pressure of the leakage diagnosis part, and judging that the pressure difference exists between the two ends of the electromagnetic valve when the pressure of the air inlet manifold of the low-load desorption pipeline is smaller than the environmental pressure of the leakage diagnosis part; or acquiring the pressurization pressure of the high-load desorption pipeline, and judging that pressure difference exists between the two ends of the electromagnetic valve under the condition that the pressurization pressure of the high-load desorption pipeline is greater than a set value.

Further, before the acquiring the solenoid valve driving signal and the tank pressure signal from the leakage diagnosing section, the canister desorption pipeline diagnosing method further includes: and under the condition that the carbon tank flushing condition is met, the electromagnetic valve is driven to be in a working state at different on/off interval cycles according to the engine load and/or the oil gas concentration in the carbon tank.

Further, before the comparing the driving period of the solenoid valve driving signal and the fluctuation period of the tank pressure signal within the same set period, the canister desorption pipeline diagnosis method further includes: acquiring continuous oil tank pressure signals, and calculating the signal change rate corresponding to the oil tank pressure signals; and acquiring a time period between positive and negative transitions of two adjacent signal change rates with the same transition direction, and determining the time period as the fluctuation cycle of the tank pressure signal.

Further, the determining whether the desorption pipeline has a fault according to the comparison result includes: configuring a normal counter and a fault counter; if the deviation between the driving period of the electromagnetic valve driving signal and the fluctuation period of the oil tank pressure signal is within a preset range, controlling the normal counter to increase, otherwise, controlling the fault counter to increase; when the count of the normal counter reaches or exceeds a first threshold value, determining that the desorption pipeline is normal; and determining that the desorption pipeline has a fault when the count of the fault counter reaches or exceeds a second threshold value.

Further, after determining that the desorption pipeline has a fault, the carbon tank desorption pipeline diagnosis method further includes: and inhibiting the corresponding desorption pipeline to perform desorption flushing.

Compared with the prior art, the carbon tank desorption pipeline diagnosis method provided by the invention realizes carbon tank desorption pipeline diagnosis by using a software strategy, and remarkably reduces diagnosis cost.

In order to achieve the above object, the technical solution of the present invention further includes:

a machine-readable storage medium having instructions stored thereon for causing a machine to perform the canister desorption pipeline diagnostic method described above.

A controller for carbon tank desorption pipeline diagnosis is used for operating a program, wherein the program is used for executing the carbon tank desorption pipeline diagnosis method.

Further, the controller is an engine control unit.

An engine comprises the controller, and the engine is applied in a manner suitable for the evaporation system.

The advantages of the machine-readable storage medium, the controller and the engine are the same as those of the carbon tank desorption pipeline diagnosis method compared with the prior art, and the detailed description is omitted.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of a conventional vehicle evaporative system;

fig. 2 is a schematic flow chart of a carbon tank desorption pipeline diagnosis method according to an embodiment of the present invention; and

fig. 3 is a logic block diagram for performing canister desorption line diagnostics in an example of an embodiment of the present invention.

Detailed Description

In addition, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Before describing the embodiment of the present invention, a vehicle evaporation system is described to facilitate understanding of the principles and details of the canister desorption line diagnostic scheme of the embodiment of the present invention.

Fig. 1 is a schematic structural diagram of a conventional vehicle evaporation system, wherein the evaporation system may include a leakage diagnosis portion and a desorption line diagnosis portion located at both ends of a solenoid valve 100 and communicating through the solenoid valve 100, with the solenoid valve 100 of a canister as a boundary according to the monitoring contents of the evaporation system. Wherein, the leakage diagnosis part comprises a fuel tank 110 and a canister 120 which are communicated in turn, and a fuel tank pressure sensor 130 mounted in cooperation with the fuel tank 110 and a shut-off valve 140 provided in cooperation with the canister 120. Further, for a supercharged engine, in order to increase the flushing flow rate to flush the carbon canister 120 clean, two desorption pipelines may be configured. That is, the desorption line diagnosis portion may include a low-load desorption line leading to the intake manifold 210 of the engine and/or a high-load desorption line leading to the rear end line of the air cleaner 220, and the low-load desorption line is mounted with the intake manifold pressure sensor 230 and the high-load desorption line is mounted with the boost pressure sensor 240. In addition, for a high-load desorption pipeline, a venturi structure is added to the desorption pipeline at the rear end of the air filter, and the diagnosis scheme of the carbon tank desorption pipeline in the prior art mentioned in the background section realizes pipeline diagnosis by adding a pressure sensor between the venturi structure and the electromagnetic valve 100.

Aiming at the problems of high cost and large diagnosis limitation of a carbon tank desorption pipeline diagnosis scheme in the prior art, the inventor of the application finds that: when normal carbon tank flushing is carried out, the phenomenon that signal fluctuation is synchronous exists in an oil tank pressure signal and an electromagnetic valve driving signal. This is because, regardless of the diagnostic requirements, in order to meet the requirements of evaporative emission and refueling emission, when the carbon canister flushing condition is met, the Engine Control Unit (ECU) drives the solenoid valve 100 to open to different degrees of opening at different on/off intervals, and the original voltage signal of the fuel tank pressure sensor 130 is also acquired by the ECU through the hard-wire sampling circuit; the pipeline connection design of the whole evaporation system is combined, namely one end (called rear end) of the electromagnetic valve 100 is connected to an air inlet manifold 210 and/or an air filter 220 of the engine through a pipeline, the other end (called front end) is connected to the carbon canister 120 through a pipeline, the carbon canister 120 is connected to the oil tank 110 through a pipeline and is in contact with the atmosphere through the stop valve 130, and the oil tank pressure sensor 130 is arranged on the pipeline from the oil tank to the carbon canister or the oil tank; when there is a pressure difference between the front and rear ends of the solenoid valve 100, the entire evaporation system pipeline is turned on/off along with the opening/closing of the solenoid valve 100 in the operating state of the solenoid valve 100, so that the air flow is synchronously fluctuated along with the opening/closing of the solenoid valve 100, and the fluctuation of the air flow can be reflected by the tank pressure signal detected by the tank pressure sensor 130.

Therefore, the core of the embodiment of the invention is to perform desorption pipeline diagnosis by extracting the fluctuation period of the signal of the oil tank pressure sensor during normal carbon tank flushing based on the characteristic that the signal fluctuation of the oil tank pressure signal and the electromagnetic valve driving signal is synchronous during normal carbon tank flushing.

Fig. 2 is a schematic flow chart of a carbon canister desorption pipeline diagnosis method according to an embodiment of the present invention, which is applied to a vehicle evaporation system including the solenoid valve 100 of the carbon canister as described above, and a leakage diagnosis portion and a desorption pipeline diagnosis portion communicated through the solenoid valve 100.

As shown in fig. 2, the carbon tank desorption pipeline diagnosis method may include the steps of:

and step S100, judging whether pressure difference exists between two ends of the electromagnetic valve when the electromagnetic valve is in a working state.

The electromagnetic valve is in a working state, which indicates that the electromagnetic valve is in a non-fault state, so that the pressure difference between the two ends of the electromagnetic valve is not the pressure difference caused by the fault of the electromagnetic valve, but the leakage diagnosis part and the desorption pipeline diagnosis part are matched to form the pressure difference between the two ends of the electromagnetic valve.

For example, for a low-load desorption pipeline and a high-load desorption pipeline, the step S100 may include: acquiring the pressure of an air inlet manifold of the low-load desorption pipeline and the environmental pressure of the leakage diagnosis part, and judging that the pressure difference exists between the two ends of the electromagnetic valve when the pressure of the air inlet manifold of the low-load desorption pipeline is smaller than the environmental pressure of the leakage diagnosis part; or acquiring the pressurization pressure of the high-load desorption pipeline, and judging that pressure difference exists between the two ends of the electromagnetic valve under the condition that the pressurization pressure of the high-load desorption pipeline is greater than a set value. And when the pressure of the intake manifold of the low-load desorption pipeline is smaller than the environmental pressure of the leakage diagnosis part or when the supercharging pressure of the high-load desorption pipeline is larger than a set value, the pressure difference between two ends of the electromagnetic valve can be determined. The set value is, for example, +10kpa, and the set value can be set in a calibration mode due to different environmental pressures at different altitudes, and +10kpa can generally indicate that the supercharger works.

Step S200 of acquiring a solenoid valve driving signal and a tank pressure signal from the leakage diagnosing section in the case where there is a pressure difference across the solenoid valve.

For example, when the carbon tank flushing condition is met, the ECU may drive the solenoid valve in a working state at different on/off interval periods according to the engine load and/or the oil gas concentration in the carbon tank, and then the ECU may directly obtain a corresponding solenoid valve driving signal. In addition, the ECU can also acquire a fuel tank pressure signal through a hard wire sampling circuit.

The pressure difference judgment, signal acquisition, and the like corresponding to the low-load desorption pipeline and the high-load desorption pipeline respectively will be described in detail with reference to examples, and are not described herein again.

And step S300, comparing the driving period of the electromagnetic valve driving signal with the fluctuation period of the oil tank pressure signal in the same set time period, and judging whether the desorption pipeline has faults or not according to the comparison result.

Preferably, before the step S300, the canister desorption pipeline diagnosis method may further include the following steps to obtain a fluctuation period of the tank pressure signal: 1) acquiring continuous oil tank pressure signals, and calculating the signal change rate corresponding to the oil tank pressure signals; and 2) acquiring a time period between positive and negative transitions of two adjacent signal change rates with the same transition direction, and determining the time period as the fluctuation cycle of the tank pressure signal.

It should be noted that the calculation of the signal change rate and the determination of the positive-negative conversion period based on the change rate will be described in more detail below with reference to examples, and will not be described herein again.

Preferably, for step S300, the determining whether the desorption pipeline has a fault according to the comparison result may include: configuring a normal counter and a fault counter; if the deviation between the driving period of the electromagnetic valve driving signal and the fluctuation period of the oil tank pressure signal is within a preset range, controlling the normal counter to increase, otherwise, controlling the fault counter to increase; when the count of the normal counter reaches or exceeds a first threshold value, determining that the desorption pipeline is normal; and determining that the desorption pipeline has a fault when the count of the fault counter reaches or exceeds a second threshold value.

More preferably, after determining that the desorption pipeline has a fault, the carbon tank desorption pipeline diagnosis method may further include: and inhibiting the corresponding desorption pipeline to perform desorption flushing.

It should be noted that, the scheme for determining the pipeline fault by using the two counters will be further described in more detail below with reference to examples, and details are not repeated here.

It is easy to know that the steps S100 to S300 can be implemented by programming, so that the embodiment of the present invention shows that the method for diagnosing a carbon tank desorption pipeline according to the embodiment of the present invention utilizes a software strategy to implement the diagnosis of the carbon tank desorption pipeline, thereby significantly reducing the diagnosis cost.

The application and effect of the carbon tank desorption pipeline diagnosis method in the embodiment of the invention in practice are further described by way of examples.

Fig. 3 is a logic block diagram of a canister desorption line diagnostic in an example of an embodiment of the present invention, which is directed to a vehicle evaporation system such as that shown in fig. 1.

The carbon tank desorption pipeline diagnostic method of this example is performed under a condition that a carbon tank flushing condition is satisfied, which is embodied as: the temperature of the cooling liquid is higher than a certain value, the oxygen sensor enters a closed loop state, and the like. Further, the carbon canister desorption line diagnosis of this example is performed by the ECU, and may include a diagnosis method for a low-load desorption line and a diagnosis method for a high-load desorption line, but the diagnosis methods for the two lines are similar, so the diagnosis method for the low-load desorption line is mainly described below, and a difference between the diagnosis method for the high-load desorption line and the low-load desorption line is specifically described.

For a low-load desorption pipeline, a manifold pressure sensor used for calculating air inflow is arranged on an air inlet manifold of the engine, and the end of a stop valve of a carbon tank is communicated with the external environment, so that the atmospheric pressure of the end is equivalent to the ambient pressure. Accordingly, the diagnostic method for a low load desorption line may comprise the steps of:

and step S301, determining that the low-load desorption pipeline diagnosis condition is met.

Wherein the low-load desorption pipeline diagnosis conditions comprise: the intake manifold pressure sensor measurement (i.e., intake manifold pressure) is less than ambient pressure, the ECU drives the solenoid valve in operation, and the canister purge condition is satisfied.

Step S302, collecting the electromagnetic valve driving signal and the oil tank pressure signal from the leakage diagnosis part, and calculating the signal change rate of the oil tank pressure signal.

For example, after the low-load desorption pipeline diagnosis condition is met, due to the periodic on/off characteristic of the electromagnetic valve, the whole evaporation system pipeline is in clearance communication along with the driving frequency of the electromagnetic valve, airflow can generate periodic pulse flow along with the on/off driving period of the electromagnetic valve under the action of pressure difference, at the moment, the oil tank pressure sensor can sense the fluctuation of the airflow, the pressure signal can generate periodic change along with the fluctuation, and the oil tank pressure sensor can be subjected to continuous circuit signal acquisition to calculate the signal change rate. It is apparent that the period of fluctuation of the solenoid valve driving signal is easily determined due to the periodic on/off characteristic of the solenoid valve.

For the calculation of the signal change rate, further for example, according to the sampling frequency of the above-mentioned sampling circuit, for example, sampling is performed every 1ms, the pressures obtained in two adjacent times are P1 and P2, and then the signal change rate is obtained by subtracting the pressure obtained in the front from the pressure obtained in the rear, namely Δ (P2-P1) is the signal change rate.

In step S303, a corresponding signal fluctuation period is calculated based on the signal change rate of the tank pressure signal.

For example, the period of the fluctuation can be calculated from the positive to negative (or negative to positive) signal rate to the next positive to negative (or negative to positive) signal rate.

And step S304, comparing the fluctuation cycle of the tank pressure signal with the fluctuation cycle of the electromagnetic valve driving signal in the same time period.

Step S305, determining whether the deviation of the fluctuation periods of the two compared signals is within a set range, if so, performing step S306, otherwise, performing step S307.

In step S306, the normal counter is incremented.

In step S307, the failure counter is incremented.

For steps S305-S307, for example, if the period deviation of the two signals is within a predetermined range (e.g. 10%), the normal counter is incremented by 1 time, otherwise, the pipeline is not normal, and the failure counter is incremented by one time.

And step S308, executed in step S306, determining that the low-load desorption pipeline is normal when the count of the normal counter reaches or exceeds the first threshold.

For example, it may be continuously counted to make a plurality of determinations, and if the normal counter is increased to a certain value (first threshold value) at a certain number of counting times, it may be determined that the low load line connection is normal without disconnection.

Step S309, which is performed in step S307, determines that the low-load desorption pipeline is faulty when the fault counter reaches or exceeds the second threshold, and executes step S310.

The first threshold and the second threshold are not related and can be set arbitrarily according to actual needs.

After the low-load pipeline is disconnected, under a small-load working condition, the real pressures at the two ends of the whole evaporation system are both ambient pressures, no pressure difference can not generate airflow flow, the pressure signal of the oil tank needs to be free of fluctuation, and the fluctuation cycle of the signal change rate is irregular or infinite. Therefore, for step S309, for example, it can be continuously counted to make a plurality of judgments, and the number of times that the deviation between the tank pressure signal fluctuation period and the solenoid valve driving signal period is within a reasonable range is less than a certain value (i.e., the number of times within an unreasonable range reaches or exceeds the second threshold), it is determined that the disconnection fault of the pipeline exists.

And step S310, inhibiting the low-load desorption pipeline from carrying out desorption flushing so as to avoid oil gas from volatilizing into the atmosphere.

Further, for a high-load desorption pipeline, the fault judgment method is similar to that for a low-load desorption pipeline, and the difference is mainly that the high-load desorption pipeline diagnosis condition does not include that the measured value of the intake manifold pressure sensor is smaller than the ambient pressure, but requires that the measured value of the supercharging pressure sensor is larger than the set value.

Based on this, the diagnostic method for a high load desorption circuit can be described, for example, as: 1) the high-load desorption pipeline is provided with a pressurization pressure sensor, the interface of the high-load desorption pipeline is arranged at the downstream of the air filter, when the measured value of the boost pressure sensor is larger than the set value, because of the pressure loss of the air filter, the pressure after air filtration is smaller than the ambient pressure, after the pipelines of the evaporation system are communicated, the two parts of the evaporation system which are bound by the electromagnetic valve have pressure difference, after the ECU drives the electromagnetic valve to work, the pipeline of the whole evaporation system is in clearance communication with the driving frequency of the electromagnetic valve due to the characteristic of periodic switching of the electromagnetic valve, the air flow can generate periodic pulse flow along with the opening/closing driving period of the electromagnetic valve under the action of pressure difference, at the moment, the oil tank pressure sensor can sense the fluctuation of the air flow, and a pressure signal can generate periodic change along with the fluctuation, because of the pressurization working condition, the fluctuation source representing the oil tank pressure at the moment comes from a high-load pipeline; 2) the method is similar to a low-load desorption pipeline diagnosis method for signal acquisition, signal change rate calculation, signal fluctuation cycle calculation and comparison, and normal and fault counting, wherein after the high-load desorption pipeline is disconnected, under a pressurization working condition, the real pressures at two ends of the whole evaporation system are both ambient pressures, no pressure difference can not generate airflow flow, the engine control unit judges that no pressure pulse fluctuation exists according to the acquired oil tank pressure sensor signal, the pressure fluctuation cycle is infinite, multiple judgments are continuously carried out, the frequency of deviation of the driving cycle of the electromagnetic valve within a reasonable range is smaller than a certain value, the high-load desorption pipeline is determined to have a disconnection fault, and desorption flushing of the high-load desorption pipeline is inhibited.

It should be noted that, in this example, the diagnosis of the high-load desorption line and the low-load desorption line may be performed simultaneously or separately, and the embodiment of the present invention does not limit this. In addition, in other examples, regarding steps S302-S309, the diagnosis may be performed by actively controlling the solenoid valve of the canister to be quickly fully opened and fully closed by the ECU, and observing the absolute value change of the tank pressure signal, but this scheme may have a significant impact on the control of the engine.

By this example, it can be seen that the carbon tank desorption pipeline diagnosis method according to the embodiment of the present invention has at least the following advantages:

1) according to the carbon tank desorption pipeline diagnosis method, diagnosis can be achieved through existing parts of a vehicle, and a ventilation stop valve of the carbon tank does not need to be closed in the diagnosis process, so that the volatilization speed of oil vapor of an oil tank cannot be increased.

2) The carbon tank desorption pipeline diagnosis method provided by the embodiment of the invention can be realized by using a software strategy, a Venturi structure or a sensor is not required to be additionally arranged on the desorption pipeline, the requirement on the operating condition of the engine is low, the implementation is easy, and the cost is low.

3) The carbon tank desorption pipeline diagnosis method provided by the embodiment of the invention can be suitable for a double-pipeline supercharged engine without desorption flow pressure, and the diagnosis can be completed without increasing a Venturi structure on a high-load desorption pipeline of the engine.

4) The carbon tank desorption pipeline diagnosis method provided by the embodiment of the invention has no special processing requirement on the fluctuation amplitude of the oil tank pressure (the fluctuation amplitude is related to the driving opening/flushing flow of the electromagnetic valve, but the flow is not concerned in the example), does not relate to the extraction and judgment of the signal frequency, and belongs to a natural detection means.

5) In the diagnosis process, the carbon tank desorption pipeline diagnosis scheme in the prior art mentioned in the background technology part also limits the operation area of an engine, so that the engine cannot operate in an economic fuel consumption area, and the fuel economy of a vehicle is influenced.

Another embodiment of the present invention also provides a machine-readable storage medium having instructions stored thereon for causing a machine to perform any of the above-described carbon canister desorption pipeline diagnostic methods.

Another embodiment of the present invention further provides a controller for diagnosing a carbon tank desorption pipeline, which is used for running a program, wherein the program is used for the above carbon tank desorption pipeline diagnosis method when running. Preferably, the controller is an ECU, but may be other vehicle controllers or otherwise configured controllers.

The invention further provides an engine which comprises the controller and is suitable for being applied to the evaporation system. The engine can be a supercharged engine or a self-priming engine.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A carbon tank desorption pipeline diagnosis method is applied to a vehicle evaporation system, the vehicle evaporation system comprises an electromagnetic valve of a carbon tank, and a leakage diagnosis part and a desorption pipeline diagnosis part which are communicated through the electromagnetic valve, and the carbon tank desorption pipeline diagnosis method comprises the following steps:

judging whether pressure difference exists between two ends of the electromagnetic valve when the electromagnetic valve is in a working state;

acquiring a solenoid valve driving signal and a tank pressure signal from the leakage diagnosing section in a case where a pressure difference exists between both ends of the solenoid valve; and

and comparing the driving period of the electromagnetic valve driving signal with the fluctuation period of the oil tank pressure signal in the same set time period, and judging whether the desorption pipeline has faults or not according to the comparison result.

2. The carbon tank desorption pipeline diagnosis method according to claim 1, wherein the desorption pipeline diagnosis part comprises a low-load desorption pipeline leading to an intake manifold of an engine and/or a high-load desorption pipeline leading to a pipeline at the rear end of an air filter;

the judging whether the pressure difference exists between the two ends of the electromagnetic valve comprises the following steps:

acquiring the pressure of an air inlet manifold of the low-load desorption pipeline and the environmental pressure of the leakage diagnosis part, and judging that the pressure difference exists between the two ends of the electromagnetic valve when the pressure of the air inlet manifold of the low-load desorption pipeline is smaller than the environmental pressure of the leakage diagnosis part; or

And acquiring the boost pressure of the high-load desorption pipeline, and judging that pressure difference exists between two ends of the electromagnetic valve under the condition that the boost pressure of the high-load desorption pipeline is greater than a set value.

3. The carbon tank desorption line diagnostic method according to claim 1, further comprising, before the acquiring a solenoid valve driving signal and a tank pressure signal from the leak diagnostic portion:

and under the condition that the carbon tank flushing condition is met, the electromagnetic valve is driven to be in a working state at different on/off interval cycles according to the engine load and/or the oil gas concentration in the carbon tank.

4. The canister desorption line diagnostic method according to claim 1, wherein before the comparing the drive cycle of the solenoid valve drive signal and the fluctuation cycle of the tank pressure signal within the same set period, the canister desorption line diagnostic method further comprises:

acquiring continuous oil tank pressure signals, and calculating the signal change rate corresponding to the oil tank pressure signals; and

and acquiring the time interval between the positive and negative conversion with the consistent direction of the two adjacent conversion directions of the signal change rate, and determining the time interval as the fluctuation cycle of the tank pressure signal.

5. The carbon tank desorption pipeline diagnosis method according to claim 1, wherein the determining whether the desorption pipeline has a fault according to the comparison result comprises:

configuring a normal counter and a fault counter;

if the deviation between the driving period of the electromagnetic valve driving signal and the fluctuation period of the oil tank pressure signal is within a preset range, controlling the normal counter to increase, otherwise, controlling the fault counter to increase;

when the count of the normal counter reaches or exceeds a first threshold value, determining that the desorption pipeline is normal; and

and when the count of the fault counter reaches or exceeds a second threshold value, determining that the desorption pipeline has a fault.

6. The carbon tank desorption line diagnostic method according to claim 5, further comprising, after the determining that the desorption line is faulty:

and inhibiting the corresponding desorption pipeline to perform desorption flushing.

7. A machine-readable storage medium having instructions stored thereon for causing a machine to perform the carbon canister desorption pipeline diagnostic method of any one of claims 1-6.

8. A controller for carbon canister desorption line diagnostics, characterized by a program, wherein the program is executed for performing a carbon canister desorption line diagnostics method according to any one of claims 1-6.

9. The controller of claim 8, wherein the controller is an Engine Control Unit (ECU).

10. An engine comprising a controller according to claim 8 or 9 and adapted for use with the evaporative system.