Diagnostic Method for Engine Boost Rationality

Abstract

The present invention relates to a method for diagnosing engine boost rationality, comprising: diagnosing whether a rationality fault has occurred based on intake pressure and ignition efficiency; if both diagnostic results indicate a fault, determining that a fault has occurred; otherwise, determining that no fault has occurred. Without affecting normal engine control, the present invention identifies the impact of intake pressure or ignition angle efficiency on the opening of a boost actuator, updates the boost actuator opening threshold, and simultaneously, as the engine life cycle progresses and the boost system ages, updates the differences in determining boost system faults in real time, identifies whether the boost system's capabilities are abnormal, and performs repairs as soon as possible when problems arise, thereby reducing the impact on engine power and economy.

Description

Technical Field

[0001] The present invention relates to the field of engine control, and more particularly to a method for diagnosing engine boost rationality. Background Art

[0002] To respond to engine intake boost and torque increases, the supercharging system controls the system to maximize exhaust gas energy for boost. This control determines engine power and economy. Therefore, it's crucial to be able to diagnose supercharging control systems and identify performance issues as soon as possible. When problems arise, repairs can be performed promptly, minimizing the impact on engine power and economy. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for diagnosing the rationality of engine supercharging, which can detect whether the supercharging system behaves abnormally when the intake pressure changes.

[0004] The technical solution adopted by the present invention to solve the technical problem is to construct a method for diagnosing the rationality of engine supercharging, including:

[0005] Diagnose whether a rational fault occurs by two methods based on intake pressure and ignition efficiency;

[0006] If the diagnosis results of both methods indicate that a fault has occurred, it is determined that a fault has occurred; otherwise, it is determined that no fault has occurred.

[0007] According to the above scheme, the method for diagnosing whether a boost fault occurs based on intake pressure includes:

[0008] The average value of the boost actuator opening corresponding to the current working condition is compared with the standard threshold to determine whether there is a rationality fault in the boost; the standard threshold of the boost actuator opening is calculated by the boost actuator opening reference value, the average value of the actual pressure of the engine throttle inlet, the average value of the actual engine intake pressure, the average value of the air excess coefficient, the average value of the actual engine intake flow, the average value of the target boost pressure, and the reference value of the actual engine intake flow.

[0009] According to the above scheme, the boost actuator opening standard threshold pct BoostActuatorLim Calculated by the following formula:

[0010]

[0011] Where, pct BoostActuatorBase is the reference value of the boost actuator opening, p BfThrAct is the actual average pressure at the engine throttle inlet, p AftThrAct is the average value of the actual intake pressure of the engine, λ is the average value of the air excess coefficient, dm Cylinderis the average value of the actual intake flow of the engine, p BoostDesird is the target boost pressure average value, dm CylinderBase is the actual intake air flow reference value of the engine; and are the correction parameters obtained during bench calibration.

[0012] According to the above scheme, the correction parameters are obtained during the bench calibration and The methods include:

[0013] exist When λ=1, the actual boost actuator opening is obtained, that is, the boost actuator opening reference value pct BoostActuatorBase , and then in different The influence of λ on the opening of the boost actuator is calibrated.

[0014] According to the above scheme, if the average opening degree of the boost actuator corresponding to the current working condition meets the standard threshold:

[0015]

[0016] It means that a rationality fault occurs; where Δ1 is the proportional threshold, Δ1=C1×(1+r Adapt1 ), C1 is a constant, r Adapt1 It is the self-learning correction value of the proportional threshold.

[0017] According to the above scheme, during each driving cycle of the vehicle, the intake pressure-based diagnosis of whether a boost fault occurs is performed at most once. After each diagnosis is completed, the number of times the intake pressure-based diagnosis of whether a boost fault occurs CNT1 and the number of times the intake pressure-based diagnosis of no fault occurs CNT2 are recorded and stored, and saved after the vehicle is powered off.

[0018] According to the above scheme, when the number of occurrences CNT1 is greater than the preset value, the vehicle mileage exceeds the preset value L1, and CNT2 is 0, the self-learning correction value r Adapt1 Updated to: Adapt1 =r Adapt1 (z)-0.02, where r Adapt (z) is the self-learning correction value of the last updated learning; after the update is completed, CNT1, CNT2 and L1 are cleared and updated again;

[0019] When the number of occurrences CNT1 is not greater than the preset value, the vehicle mileage L1 exceeds the preset value, and CNT2 = 10, the self-learning correction value r Adapt1 Updated to: Adapt1 =r Adapt1 (z) + 0.01, where rAdapt1 (z) is the self-learning correction value of the last updated learning; after the update is completed, CNT1, CNT2 and L1 are cleared and updated again;

[0020] In addition to the above, r Adapt1 =r Adapt1 (z).

[0021] According to the above scheme, the method for diagnosing whether a supercharging fault occurs based on ignition efficiency includes:

[0022] The average value of the boost actuator opening corresponding to the current working condition is compared with the standard threshold to determine whether there is a rationality fault in the boost; the standard threshold of the boost actuator opening is calculated through the boost actuator opening reference value, the ignition efficiency average value, the basic ignition efficiency average value, the air excess coefficient average value, the actual engine intake flow average value, and the actual engine intake flow reference value.

[0023] According to the above scheme, the boost actuator opening standard threshold pct BoostActuatorLim Calculated by the following formula:

[0024]

[0025] Where, pct BoostActuatorBase is the boost actuator opening reference value, r Spark is the average ignition efficiency, r BaseSpark is the average value of basic ignition efficiency, λ is the average value of air excess coefficient, dm Cylinder is the average value of the actual intake flow of the engine, dm CylinderBase is the actual intake air flow reference value of the engine; and are the correction parameters obtained during bench calibration.

[0026] According to the above scheme, the correction parameters are obtained during the bench calibration and The methods include:

[0027] When the target boost pressure is fixed, set When λ=1, the actual boost actuator opening is obtained, that is, the boost actuator opening reference value pct BoostActuatorBase , and then in different The influence of λ on the opening of the boost actuator is calibrated.

[0028] According to the above scheme, if the average opening degree of the boost actuator corresponding to the current working condition and the standard threshold meet one of the following conditions:

[0029] (1) The throttle valve enters the fully open state

[0030] |pct BoostActuator -pct BoostActuatorLim |≥Δ2

[0031] (2) The throttle valve is not fully open

[0032]

[0033] This indicates a rationality failure.

[0034] Where Δ2 is the proportional threshold, Δ2=C2×(1+r Adapt2 ), C2 is a constant, r Adapt2 is the self-learning correction value of the proportional threshold, It is the ratio of the average actual intake pressure of the engine to the average actual pressure at the throttle inlet.

[0035] According to the above scheme, during each driving cycle of the vehicle, the diagnosis of whether a boost fault occurs based on the ignition efficiency is performed at most once. After each diagnosis is completed, the number of times the ignition efficiency-based diagnosis of whether a boost fault occurs CNT3 and the number of times the ignition efficiency-based diagnosis of no fault occurs CNT4 are recorded and stored, and saved after the vehicle is powered off.

[0036] According to the above scheme, when the number of occurrences CNT3 is greater than the preset value, the vehicle mileage exceeds the preset value L2, and CNT4 is 0, the self-learning correction value r Adapt2 Updated to: Adapt2 =r Adapt2 (z)-0.02, where r Adapt2 (z) is the self-learning correction value of the last updated learning; after the update is completed, CNT3, CNT4 and L2 are cleared and the cumulative update is restarted;

[0037] When the number of occurrences CNT3 is greater than the preset value, the vehicle mileage L2 exceeds the preset value, and CNT4 = 10, the self-learning correction value r Adapt2 Updated to: Adapt2 =r Adapt2 (z) + 0.01, where r Adapt2 (z) is the self-learning correction value of the last updated learning; after the update is completed, CNT3, CNT4 and L2 are cleared and the cumulative update is restarted;

[0038] In addition to the above, r Adapt2 =r Adapt2 (z).

[0039] The present invention also provides an electronic device comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the engine boost rationality diagnosis method.

[0040] The implementation of the engine boost rationality diagnosis method of the present invention has the following beneficial effects:

[0041] Without affecting the normal control of the engine, the present invention identifies the influence of intake pressure or ignition angle efficiency on the opening of the boost actuator and updates the boost actuator opening threshold. At the same time, as the engine life cycle progresses and the boost system ages, the present invention updates the difference in judging boost system failures in real time, identifies whether the boost system capacity is abnormal, and performs maintenance as soon as possible when problems occur, thereby reducing the impact on the engine's power and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0043] Figure 1 is a flow chart of the engine boost rationality diagnosis method of the present invention;

[0044] Figure 2 It is a logic block diagram of the engine boost rationality diagnosis method of the present invention. DETAILED DESCRIPTION

[0045] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0046] Example 1

[0047] The engine boost rationality diagnosis method of the present invention must meet certain conditions, which are as follows:

[0048] 1. Boost control is in closed-loop control. The boost control closed-loop control conditions can be found in patent CN201910988050.8, "Exhaust Gas Turbine Engine Boost Closed-Loop Adaptive System and Control Method."

[0049] 2. The engine speed fluctuation is within a preset range. In this example, the preset range is ±15 rpm.

[0050] 3. The actual engine intake pressure (the actual value of the intake pressure at the throttle outlet, i.e., the actual value of the gas pressure entering the cylinder) fluctuates within a preset range. In this example, ±2 kPa is used.

[0051] 4. The target engine intake pressure (the target value of the intake pressure at the throttle valve outlet, i.e., the target value of the gas pressure entering the cylinder) fluctuates within a preset range. In this example, ±2 kPa is used.

[0052] 5. The difference between the target opening of the boost actuator and the actual opening (the larger the opening, the stronger the boost capability, the opening changes from 0% to 100%) is within a preset range, which in this example is ±1%.

[0053] 6. The throttle opening fluctuation is within the preset range, which is ±1% in this example.

[0054] 7. The actual opening fluctuation of the boost actuator is within the preset range, which is ±1% in this example.

[0055] 8. The target boost pressure (for details, see patent CN202010109549.X "Method for Determining Target Boost Pressure of Exhaust Gas Turbocharged Engine, Storage Medium") fluctuates within a preset range, which in this example is ±2 kPa.

[0056] 9. The difference between the target boost pressure and the actual boost pressure is within a preset range, which in this example is ±2 kPa.

[0057] 10. The engine water temperature is within the preset range, which in this example is 60°C to 100°C, and the engine water temperature fluctuation is within the preset range, which in this example is ±3°C.

[0058] 11. The difference between the target air-fuel ratio and the actual air-fuel ratio is within a preset range, which in this example is ±0.05.

[0059] 12. The target air-fuel ratio fluctuation is within a preset range, which in this example is ±0.02.

[0060] 13. The final ignition angle efficiency of the engine fluctuates within a preset range, which in this example is ±0.05.

[0061] 14. The engine's basic ignition angle efficiency (the definition of basic ignition angle efficiency can be found in patent CN202110717601.4 "Calculation Method, Computer Equipment and Storage Medium for Engine Basic Ignition Efficiency") fluctuates within a preset range. In this example, ±0.05 is used.

[0062] 15. The engine did not experience fuel shortage.

[0063] 16. EGR rate is 0.

[0064] 17. No faults occurred in the sensors related to the boost system.

[0065] 18. No faults occurred in the actuators related to the boost system.

[0066] 19. No GPF-related faults occurred.

[0067] 20. No catalyst-related faults occurred.

[0068] 21. No boost rationality fault diagnosis was performed during this vehicle driving cycle.

[0069] The engine boost rationality diagnosis can only be performed after all of the above conditions have been met for a period exceeding the preset time t0 (2 seconds in this example). If all of the above conditions are not met during the engine boost rationality diagnosis, the diagnosis is terminated. The recording and collection of engine boost rationality diagnosis data can only be resumed in the current driving cycle after all of the above conditions are met again.

[0070] like Figure 1 As shown, the engine boost rationality diagnosis method includes the following steps:

[0071] S1. First type of intake pressure failure check: Based on the intake pressure diagnosis to see if there is a reasonable fault, it can only be performed if the following conditions are met:

[0072] 1) The ratio of the average actual engine intake pressure during time t0 to the average actual engine throttle inlet pressure must not exceed a preset value A1, as shown in Table 1. In this example, the preset value is related to the average engine speed. A larger pressure ratio deteriorates intake control stability, which can easily lead to false failure detection.

[0073] Table 1

[0074]

[0075] 2) The average ignition angle efficiency during time t0 is no greater than a preset value (0.3 in this example). The lower the ignition angle efficiency, the worse the engine combustion stability, and the accuracy of failure detection based on ignition efficiency is relatively low.

[0076] After checking for reasonableness faults based on intake pressure diagnosis, identical engine speed, actual engine intake flow, engine water temperature, engine ignition angle efficiency, and target boost pressure are considered identical operating conditions. The average values ​​of the current engine speed, actual engine intake flow, engine water temperature, actual engine throttle inlet pressure, actual engine intake pressure, target boost pressure, exhaust temperature, engine ignition angle efficiency, actual boost actuator opening, and the ratio of the actual air-fuel ratio (the actual air-fuel ratio can be detected by the wideband oxygen sensor in the exhaust system) to the ideal air-fuel ratio (the equivalent air-fuel ratio is set to 14.3 in this example and is determined by the fuel quality) (referred to as the air excess coefficient) are calculated.

[0077] The average value of the boost actuator opening pct of the current working conditions (average engine speed, average actual engine intake flow, average engine water temperature, average engine ignition angle efficiency, average target boost pressure) BoostActuator With the standard threshold pct BoostActuatorLim Make a comparison to determine whether there is a rationality fault in the boost.

[0078] The boost actuator opening standard threshold pct BoostActuatorLim The actual opening average value of the boost actuator pct BoostActuator , the actual average pressure at the engine throttle inlet p BfThrAct , the average value of the actual engine intake pressure p AftThrAct , average value of air excess coefficient λ, average value of actual engine intake flow dm Cylinder , target boost pressure average value p BoostDesird , the actual engine intake flow reference value dm CylinderBase related.

[0079]

[0080] At the same throttle inlet pressure, if the ratio of the actual engine intake pressure to the engine throttle inlet pressure is smaller, it means that the throttle pressure drop is larger. At this time, the throttle outlet pressure and the intake flow into the cylinder are smaller, and the exhaust energy is smaller. To achieve the same boost pressure, a larger boost actuator opening is required; pressure ratio The smaller it is, the more it affects the exhaust capacity. The larger the opening of the boost actuator is, the same boost pressure can be achieved. The larger the average value of the air excess coefficient λ is, the more air accounts for the mixture, and the higher the exhaust temperature is. Under the same engine intake density, the smaller the exhaust energy is, and the larger the opening of the boost actuator is, the same boost pressure can be achieved.

[0081] Actual engine intake flow reference value dm CylinderBase , is the reference value of the intake flow rate, which is 15g / s in this example. and The method of obtaining is on the engine test bench, first When λ=1, the actual boost actuator opening is obtained, that is, the boost actuator opening reference value pct BoostActuatorBase , and then in different The influence of the opening degree of the boost actuator under λ is calibrated. Based on this, the calibration data of this example are shown in Table 2 and Table 3:

[0082] Table 2

[0083]

[0084] Table 3

[0085]

[0086] Compare the average opening degree of the boost actuator pct BoostActuator With the standard threshold pct BoostActuatorLim The difference can be used to determine whether there is a boost rationality fault.

[0087]

[0088] If the above formula is satisfied, a single occurrence of the first type of intake pressure failure (unconfirmed) occurs. Otherwise, no first type of intake pressure failure occurs. Once the first type of intake pressure failure (unconfirmed) occurs more than a preset number of times (50 in this example), a first type of intake pressure failure occurs. After a first type of intake pressure failure occurs, the first type of intake pressure failure will not be tested again until the fault is cleared by the aftermarket 4S dealership.

[0089] The following additional information is required:

[0090] Where Δ1 is the ratio threshold, Δ1=C1×(1+r Adapt1 ), C1 is a constant, which is 0.2 in this example. Adapt1 This is the self-learning correction value for the proportional threshold. Its initial value is 0 and is saved when the vehicle is powered off. During each drive cycle, a boost rationality fault is detected at most once. If the test is complete, it will not be tested again for that drive cycle until the next drive cycle meets the diagnostic criteria. After each test, the number of diagnostic satisfaction times (CNT1) and the number of times the fault was diagnosed as not occurring (CNT2) are recorded and stored, and saved after the vehicle is powered off.

[0091] if,

[0092] (1) The number of occurrences CNT1 is greater than the preset value (10,000 times in this example), the vehicle mileage L1 used for boost rationality diagnosis exceeds the preset value (10,000 kilometers in this example), and CNT2 is 0, then the self-learning correction value r Adapt1 Updated to: Adapt1 =r Adapt1 (z)-0.02, where r Adapt1 (z) is the self-learning correction value of the last update. After the update is completed, CNT1, CNT2 and L1 are cleared and then accumulated and updated again.

[0093] (2) The number of occurrences CNT1 is greater than the preset value (100 times in this example), the vehicle mileage L1 used for boost rationality diagnosis exceeds the preset value (8,000 kilometers in this example), and CNT2 is 10, then the self-learning correction value r Adapt1 Updated to: Adapt1 =r Adapt1 (z) + 0.01, where r Adapt1 (z) is the self-learning correction value of the last update. After the update is completed, CNT1, CNT2 and L1 are cleared and then accumulated and updated again.

[0094] In other cases, r Adapt1 =r Adapt1 (z).

[0095] It should be noted that the self-learning correction value r Adapt1 The value increased each time (in this example, 0.01 each time) is greater than the self-learning correction value r Adapt1 The reason why the value decreased each time it is updated (in this example, it decreases by 0.02 each time) is small is that the update of the threshold does not make it more difficult to diagnose the fault. This is mainly because the probability of supercharging failure is greater as the supercharging life cycle continues to progress, and it is avoided that the supercharging failure is not diagnosed in time and the engine power and economy are lost.

[0096] S2. Second type of intake pressure failure check: This check is based on the ignition efficiency to diagnose whether a reasonable fault has occurred. This check can only be performed if the following conditions are met:

[0097] 1) The ratio of the average actual engine intake pressure during time t0 to the average actual engine throttle inlet pressure must not exceed a preset value A2. In this example, the preset value is related to the average engine speed, as shown in Table 4. A larger pressure ratio deteriorates intake control stability, which can easily lead to false failure detection.

[0098] Table 4

[0099]

[0100] 2) The average ignition angle efficiency during time t0 is greater than a preset value B2, which in this example is 0.5. The lower the ignition angle efficiency, the worse the engine combustion stability, and the accuracy of failure detection based on ignition efficiency is relatively low.

[0101] After entering the supercharged engine boost rationality diagnosis, identical engine speed, actual engine intake flow, engine water temperature, actual engine intake pressure, and target boost pressure are considered identical operating conditions. The average values ​​of the current engine speed, actual engine intake flow, engine water temperature, actual engine throttle inlet pressure, actual engine intake pressure, target boost pressure, exhaust temperature, ignition angle efficiency, actual boost actuator opening, and the ratio of the actual air-fuel ratio (the actual air-fuel ratio can be detected by the wide-band oxygen sensor in the exhaust system) to the ideal air-fuel ratio (the equivalent air-fuel ratio is set to 14.3 in this example and is determined by the fuel quality) (referred to as the air excess coefficient) are calculated.

[0102] The average value of the boost actuator opening pct of the current working conditions (average engine speed, average actual engine intake flow, average engine water temperature, average actual engine intake pressure, average target boost pressure) BoostActuator With the standard threshold pct BoostActuatorLim Make a comparison to determine whether there is a rationality fault in the boost.

[0103] The boost actuator opening standard threshold pct BoostActuatorLim The actual opening average value of the boost actuator pct BoostActuator , average ignition efficiency r Spark , average value of basic ignition efficiency r BaseSpark , average value of air excess coefficient λ, average value of actual engine intake flow dm Cylinder , the actual engine intake flow reference value dm CylinderBase related.

[0104]

[0105] The ignition efficiency affects the exhaust energy, which in turn affects the ability of the boost control itself. Under the same engine intake flow, the lower the ignition efficiency, the greater the exhaust energy, and the smaller the boost actuator opening can achieve the same boost pressure. Therefore, under the same boost pressure, the smaller the boost actuator opening; the engine intake flow also affects the exhaust capacity. The larger the intake flow, the smaller the boost actuator opening can achieve the same boost pressure; the larger the average value of the air excess coefficient λ, the more air accounts for the mixture, and the higher the exhaust temperature is relatively. Under the same engine intake density, the smaller the exhaust energy, and thus the larger the boost actuator opening can achieve the same boost pressure.

[0106] Actual engine intake flow reference value dm CylinderBase , is the reference value of the intake flow rate, which is 15g / s in this example. and The method of obtaining the boost pressure is to first set the target boost pressure on the engine test bench. When λ=1, the actual boost actuator opening is obtained, that is, the boost actuator opening reference value pct BoostActuatorBase , and then in different The influence of the opening degree of the boost actuator under λ is calibrated. Based on this, the calibration data of this example are shown in Table 5 and Table 6:

[0107] Table 5

[0108]

[0109]

[0110] Table 6

[0111]

[0112] Compare the average opening degree of the boost actuator pct BoostActuator With the standard threshold pct BoostActuatorLim The difference can be used to determine whether there is a boost rationality fault.

[0113] 1) The throttle valve enters the fully open state (the fully open state means that the ratio of the actual engine intake pressure to the throttle valve inlet gas pressure is not less than the preset value, which is 0.98 in this example; and the throttle valve opening exceeds the preset value, which is 95% in this example)

[0114] |pct BoostActuator -pct BoostActuatorLim |≥Δ2

[0115] 2) The throttle valve is not in the fully open state (the fully open state means that the ratio of the throttle valve outlet gas pressure to the throttle valve inlet gas pressure is not less than the preset value. In this example, the preset value is 0.98)

[0116]

[0117] If either of the above two conditions is met, a second intake pressure failure has occurred; otherwise, no second intake pressure failure has occurred. If the number of unconfirmed second intake pressure failures exceeds a preset number (50 in this example), a second intake pressure failure has occurred. After the second intake pressure failure, no further second intake pressure failure checks are performed until the fault is cleared by the aftermarket 4S dealership.

[0118] Among them, Δ2 is the opening threshold, Δ2=C2×(1+r Adapt2 ), C2 is a constant, which is 5% in this example. Adapt2It is the self-learning correction value of the opening threshold, and its initial value is 0. It can be saved when the vehicle is powered off. BfThrAct is the actual average pressure at the engine throttle inlet, p AftThrAct It is the actual average value of the engine intake pressure. It is based on the ratio of the average actual intake pressure of the engine to the average actual pressure at the throttle inlet. The smaller the ratio, the greater the throttle throttling effect, and a greater boost capacity is required to maintain the stability of the boost pressure. Therefore, the larger the opening of the boost actuator, the larger the threshold will be appropriately increased. It can be obtained through calibration, as shown in Table 7.

[0119] Table 7

[0120]

[0121] The second intake pressure failure detection method can be used only once during each drive cycle. If the test is complete, it will not be repeated for that drive cycle until the next drive cycle when the diagnostic conditions are met. After each test is completed, the number of diagnostic satisfaction times (CNT3) and the number of times no faults were diagnosed (CN4) are recorded and stored, and saved after the vehicle is powered off.

[0122] if,

[0123] (1) The number of occurrences CNT3 is greater than the preset value (10,000 times in this example), the vehicle mileage L2 used for boost rationality diagnosis exceeds the preset value (10,000 kilometers in this example), and CNT4 is 0, then the self-learning correction value r Adapt2 Updated to: Adapt2 =r Adapt2 (z)-0.02, where r Adapt2 (z) is the self-learning correction value of the last update. After the update is completed, CNT3, CNT4, and L2 are cleared and then accumulated and updated again.

[0124] (2) The number of occurrences CNT3 is greater than the preset value (100 times in this example), the vehicle mileage L2 used for boost rationality diagnosis exceeds the preset value (8,000 kilometers in this example), and CNT4 is 10, then the self-learning correction value r Adapt2 Updated to: Adapt2 =r Adapt2 (z) + 0.01, where r Adapt2 (z) is the self-learning correction value of the last update. After the update is completed, CNT3, CNT4, and L2 are cleared and then accumulated and updated again.

[0125] In other cases, r Adapt2 =r Adapt2 (z).

[0126] It should be noted that the self-learning correction value r Adapt2 The value increased each time (in this example, 0.01 each time) is greater than the self-learning correction value r Adapt2 The reason why the value decreased each time it is updated (in this example, it decreases by 0.02 each time) is small is that the update of the threshold does not make it more difficult to diagnose the fault. This is mainly because the probability of supercharging failure is greater as the supercharging life cycle continues to progress, and it is avoided that the supercharging failure is not diagnosed in time and the engine power and economy are lost.

[0127] S3. If a reasonable fault is diagnosed based on both the intake pressure and the ignition efficiency, it means that a fault has occurred; otherwise, the fault has not occurred.

[0128] Example 2

[0129] The present invention also provides an electronic device comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the engine boost rationality diagnosis method.

[0130] Example 3

[0131] The present invention also provides a computer-readable storage medium having executable instructions stored thereon. When the instructions are executed by a processor, the processor implements the engine boost rationality diagnosis method.

[0132] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0133] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0134] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0135] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0136] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A method for diagnosing engine boost rationality, characterized in that: include: Diagnose whether a rational fault occurs by two methods based on intake pressure and ignition efficiency; If the diagnosis results of both methods indicate that a fault has occurred, it is determined that a fault has occurred; otherwise, it is determined that no fault has occurred; Methods for diagnosing whether a boost fault occurs based on intake pressure include: Compare the average opening value of the boost actuator corresponding to the current working condition with the standard threshold to determine whether the boost is reasonable. Calculated by the following formula: Where, is the boost actuator opening reference value, is the actual average pressure at the engine throttle inlet, is the average value of the actual intake pressure of the engine, is the average value of the excess air coefficient, is the average value of the actual intake flow rate of the engine, is the target boost pressure average value, is the actual intake air flow reference value of the engine; and are the correction parameters obtained during bench calibration; Methods for diagnosing whether a boost fault occurs based on ignition efficiency include: Compare the average opening degree of the boost actuator corresponding to the current working condition with the standard threshold to determine whether there is a rationality fault in the boost; The boost actuator opening standard threshold Calculated by the following formula: Where, is the boost actuator opening reference value, is the average ignition efficiency, is the average value of basic ignition efficiency, is the average value of the excess air coefficient, is the average value of the actual intake flow rate of the engine, is the actual intake air flow reference value of the engine; and are the correction parameters obtained during bench calibration.

2. The engine boost rationality diagnosis method according to claim 1, characterized in that: Correction parameters obtained during bench calibration and The methods include: exist 、 、 、 The actual boost actuator opening is obtained, that is, the boost actuator opening reference value , and then in different 、 、 、 The influence of the change in the opening of the boost actuator is calibrated.

3. The engine boost rationality diagnosis method according to claim 1, characterized in that: If the average opening degree of the boost actuator corresponding to the current working condition meets the standard threshold: It means that a rational failure occurs; is the average opening degree of the boost actuator, is the ratio threshold, , C1 is a constant, It is the self-learning correction value of the proportional threshold.

4. The engine boost rationality diagnosis method according to claim 3, characterized in that: During each driving cycle of the vehicle, the intake pressure-based diagnosis of whether a boost fault occurs is performed at most once. After each diagnosis is completed, the number of times the intake pressure-based diagnosis of whether a boost fault occurs CNT1 and the number of times the intake pressure-based diagnosis of no fault occurs CNT2 are recorded and stored, and saved after the vehicle is powered off.

5. The engine boost rationality diagnosis method according to claim 4, characterized in that: When the number of occurrences CNT1 is greater than the preset value, the vehicle mileage exceeds the preset value L1, and CNT2 is 0, the self-learning correction value Updated to: ,in It is the self-learning correction value of the last updated learning; After the update is completed, CNT1, CNT2 and L1 are cleared and updated again; When the number of occurrences CNT1 is not greater than the preset value, the vehicle mileage L1 exceeds the preset value, and CNT2=10, the self-learning correction value Updated to: ,in It is the self-learning correction value of the last updated learning; After the update is completed, CNT1, CNT2 and L1 are cleared and updated again; In addition to the above, .

6. The engine boost rationality diagnosis method according to claim 1, characterized in that: Correction parameters obtained during bench calibration and The methods include: When the target boost pressure is fixed, set 、 、 The actual boost actuator opening is obtained, that is, the boost actuator opening reference value , and then in different 、 、 The influence of the change in the opening of the boost actuator is calibrated.

7. The engine boost rationality diagnosis method according to claim 1, characterized in that: If the average opening degree of the boost actuator corresponding to the current working condition and the standard threshold meet one of the following conditions: (1) The throttle valve enters the fully open state (2) The throttle valve is not fully open This indicates a rationality failure. In the formula is the average opening degree of the boost actuator, is the ratio threshold, , C2 is a constant, is the self-learning correction value of the proportional threshold, It is the ratio of the average actual intake pressure of the engine to the average actual pressure at the throttle inlet.

8. The engine boost rationality diagnosis method according to claim 7, characterized in that: During each driving cycle of the vehicle, the diagnosis of whether a boost fault occurs based on the ignition efficiency is performed at most once. After each diagnosis is completed, the number of times the ignition efficiency-based diagnosis of whether a boost fault occurs CNT3 and the number of times the ignition efficiency-based diagnosis of no fault occurs CNT4 are recorded and stored, and saved after the vehicle is powered off.

9. The engine boost rationality diagnosis method according to claim 8, characterized in that: When the number of occurrences CNT3 is greater than the preset value, the vehicle mileage exceeds the preset value L2, and CNT4 is 0, the self-learning correction value Updated to: ,in It is the self-learning correction value of the last updated learning; After the update is completed, clear CNT3, CNT4 and L2, and re-accumulate and update; When the number of occurrences CNT3 is greater than the preset value, the vehicle mileage L2 exceeds the preset value, and CNT4=10, the self-learning correction value Updated to: ,in It is the self-learning correction value of the last updated learning; After the update is completed, clear CNT3, CNT4 and L2, and re-accumulate and update; In addition to the above, .

10. An electronic device comprising: A processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; characterized in that a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the engine boost rationality diagnosis method according to any one of claims 1 to 9.

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