Engine supercharging rationality diagnosis method

Abstract

The invention relates to an engine supercharging rationality diagnosis method. The method comprises the steps that whether a rationality fault occurs or not is diagnosed based on the air inlet pressure and the ignition efficiency; if the diagnosis results of the two modes are faults, judging that the faults occur, otherwise, judging that the faults do not occur. On the premise that normal control of the engine is not affected, the influence of the air inlet pressure or the ignition angle efficiency and the like on the opening degree of the supercharging actuator is recognized, the opening degree threshold value of the supercharging actuator is updated, meanwhile, along with passing of the life cycle of the engine and along with aging of the supercharging system, the judgment difference for judging faults of the supercharging system is updated in real time, and the fault diagnosis accuracy is improved. Whether the capacity of the supercharging system is abnormal or not is recognized, maintenance is conducted as soon as possible when problems occur, and therefore the influence on the dynamic property and economical efficiency of an engine is reduced.

Description

Technical Field

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

[0002] In order to respond to the engine intake boost and engine torque increase request, the boost system is controlled to achieve more exhaust energy to achieve boost. The boost control determines the engine's power and economy, etc. Therefore, it is urgent to diagnose the boost control system and determine whether the boost system has performance problems as soon as possible. When problems occur, repairs can be carried out as soon as possible to reduce the impact on the engine's 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 boost, which can detect whether the boost system behaves abnormally when the intake pressure changes.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing an engine supercharging rationality diagnosis method, comprising:

[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 the 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 engine throttle inlet pressure, 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 target boost pressure average value, and the actual engine intake flow reference value.

[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 boost actuator opening reference value, 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 excess air coefficient, dm Cylinderis the average value of the actual intake flow rate of the engine, p BoostDesird is the target boost pressure average value, dm CylinderBase It 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 value of the boost actuator corresponding to the current working condition meets the standard threshold:

[0015]

[0016] It indicates that a rationality fault has occurred; 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, 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 by 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 rate of the engine, dm CylinderBase It 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 value meet one of the following conditions:

[0029] (1) The throttle valve is fully open

[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 ratio 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 CNT3 of whether a boost fault occurs based on the ignition efficiency diagnosis and the number of times CNT4 of no fault diagnosis based on the ignition efficiency diagnosis 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 updated again;

[0037] When the number of occurrences CNT3 is greater than the preset value, the vehicle mileage L2 exceeds the preset value, 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 updated again;

[0038] In addition to the above, 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] The present invention identifies the influence of intake pressure or ignition angle efficiency on the opening of the boost actuator without affecting the normal control of the engine, and updates the threshold of the boost actuator opening. At the same time, as the life cycle of the engine progresses and the boost system ages, the difference in judging boost system failures is updated in real time to identify whether the boost system capacity is abnormal. When a problem occurs, maintenance is performed as soon as possible, thereby reducing the influence on the engine 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 supercharging 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] Embodiment 1

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

[0048] 1. The boost control is in a closed-loop control state. 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 the preset range. In this example, the preset range is ±15rpm.

[0050] 3. The actual intake pressure of the engine (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 taken.

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

[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 varies from 0% to 100%) is within a preset range, which is ±1% in this example.

[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 turbocharger engine, storage medium") fluctuates within a preset range, and in this example, it is ±2kPa.

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

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

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

[0059] 12. The target air-fuel ratio fluctuates 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 basic ignition angle efficiency of the engine (the definition of the basic ignition angle efficiency can be found in patent CN202110717601.4 "Calculation method, computer equipment and storage medium for basic ignition efficiency of the engine") fluctuates within a preset range. In this example, ±0.05 is taken.

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

[0063] 16. The EGR rate is 0.

[0064] 17. No fault 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 in this vehicle driving cycle.

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

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

[0071] S1. The 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 value of the actual engine intake pressure during the time t0 to the average value of the actual engine throttle inlet pressure does not exceed the preset value A1, as shown in Table 1. The preset value in this example is related to the average engine speed. The larger the pressure ratio, the worse the intake control stability, which is prone to cause failure misjudgment.

[0073] Table 1

[0074]

[0075] 2) The average value of the ignition angle efficiency during the time t0 is not greater than the preset value, which is 0.3 in this example. The lower the ignition angle efficiency, the worse the engine combustion stability, and the accuracy of failure detection using ignition efficiency is relatively poor.

[0076] After entering the rationality fault check based on intake pressure diagnosis, the same engine speed, actual engine intake flow, engine water temperature, engine ignition angle efficiency, and target boost pressure are considered to be the same working conditions. Calculate the average value of the current engine speed, the average value of the actual engine intake flow, the average value of the engine water temperature, the average value of the actual engine throttle inlet pressure, the average value of the actual engine intake pressure, the average value of the target boost pressure, the average value of the engine exhaust temperature, the average value of the engine ignition angle efficiency, the average value of the actual opening of the boost actuator, and the average value of 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 in this example is 14.3, which is determined by the oil quality) (referred to as the air excess coefficient).

[0077] The average value of the boost actuator opening degree 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 reasonable fault in the boost pressure.

[0078] The boost actuator opening standard threshold pct BoostActuatorLim Compared with the actual opening average value of the boost actuator pct BoostActuator , the average actual pressure at the engine throttle inlet p BfThrAct , the average value of the actual engine intake pressure p AftThrAct , average value of excess air coefficient λ, average value of actual engine intake flow dm Cylinder 、Target boost pressure average value p BoostDesird , the actual engine intake flow rate 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 mixed gas, 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 rate reference value dm CylinderBase , is the reference value of the intake flow rate, which is 15g / s in this example, where 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 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 of the boost actuator pct BoostActuator With the standard threshold pct BoostActuatorLim The difference can be used to determine whether a boost rationality failure occurs.

[0087]

[0088] When the above formula is satisfied, it indicates that the first intake pressure failure unconfirmed fault has occurred once, otherwise it indicates that the first intake pressure failure has not occurred. Once the number of times the first intake pressure failure unconfirmed fault occurs exceeds the preset number, which is 50 times in this example, it indicates that the first intake pressure failure has occurred. After the first intake pressure failure occurs, the first intake pressure failure will no longer be checked until the fault is cleared by the after-sales 4S shop.

[0089] The following additional information is required:

[0090] Among them, Δ1 is the ratio threshold, Δ1=C1×(1+r Adapt1 ), C1 is a constant, which is 0.2 in this example. Adapt1 It is the self-learning correction value of the proportional threshold, and its initial value is 0, and it can be saved when the vehicle is powered off. During each driving cycle of the vehicle, the boost rationality fault is detected at most once. If the detection has been completed, the current driving cycle will not be detected again until the next driving cycle of the vehicle meets the diagnostic conditions. After each detection is completed, the number of times the diagnosis is satisfied CNT1 and the number of times the diagnosis is not faulty CNT2 will be 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 updated learning. 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 updated learning. 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 (in this example, it decreases by 0.02 each time) is small is that the update of the threshold value will 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 advance, and the loss of engine power and economy due to failure to timely judge the supercharging failure is avoided.

[0096] S2. The second type of intake pressure failure check: based on the ignition efficiency diagnosis to see if there is a reasonable fault, it can only be performed if the following conditions are met:

[0097] 1) The ratio of the average value of the actual engine intake pressure during the time t0 to the average value of the actual engine throttle inlet pressure shall not exceed the preset value A2. The preset value in this example is related to the average engine speed, as shown in Table 4. The larger the pressure ratio, the worse the intake control stability, which is prone to cause failure misjudgment.

[0098] Table 4

[0099]

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

[0101] After entering the turbocharger rationality diagnosis of the turbocharged engine, the same engine speed, actual engine intake flow, engine water temperature, actual engine intake pressure, and target boost pressure are considered to be the same working conditions. Calculate the average value of the current engine speed, the average value of the actual engine intake flow, the average value of the engine water temperature, the average value of the actual engine throttle inlet pressure, the average value of the actual engine intake pressure, the average value of the target boost pressure, the average value of the engine exhaust temperature, the average value of the engine ignition angle efficiency, the average value of the actual opening of the boost actuator, and the average value of the ratio of the actual air-fuel ratio (the actual value of the 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 in this example is 14.3, which is determined by the oil quality) (referred to as the air excess coefficient).

[0102] The average value of the boost actuator opening degree 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 reasonable fault in the boost pressure.

[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 、Basic ignition efficiency average value r BaseSpark , average value of excess air coefficient λ, average value of actual engine intake flow dm Cylinder , the actual engine intake flow rate reference value dm CylinderBase related.

[0104]

[0105] The ignition efficiency affects the exhaust energy, thus affecting 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 mixed gas, 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] The actual engine intake flow rate reference value dm CylinderBase , is the reference value of the intake flow rate, which is 15g / s in this example, where 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 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 of the boost actuator pct BoostActuator With the standard threshold pct BoostActuatorLim The difference can be used to determine whether a boost rationality failure occurs.

[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. The preset value in this example is 0.98)

[0116]

[0117] When one of the above two conditions is met, it indicates that the second intake pressure failure has occurred once, otherwise it indicates that the second intake pressure failure has not occurred. Once the number of unconfirmed failures of the second intake pressure failure exceeds the preset number, which is 50 times in this example, it indicates that the second intake pressure failure has occurred. After the second intake pressure failure, the second intake pressure failure will no longer be performed until the fault is cleared by the after-sales 4S shop.

[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, and 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 effect of the throttle, 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 greater the threshold value will be appropriately increased. It can be obtained by calibration, as shown in Table 7.

[0119] Table 7

[0120]

[0121] During each driving cycle of the vehicle, the second intake pressure failure inspection method is tested at most once. If the inspection has been completed, the inspection will not be performed again in this driving cycle until the vehicle meets the diagnostic conditions in the next driving cycle. After each inspection is completed, the number of times the diagnosis is satisfied CNT3 and the number of times the diagnosis is not faulty CN4 will be 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 updated learning. 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 updated learning. After the update is completed, CNT3, CNT4, and L2 are cleared and then accumulated and updated again.

[0125] In other cases, 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 (in this example, it decreases by 0.02 each time) is small is that the update of the threshold value will 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 advance, and the loss of engine power and economy due to failure to timely judge the supercharging failure is avoided.

[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] Embodiment 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] Embodiment 3

[0131] The present invention also provides a computer-readable storage medium on which executable instructions are stored. 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 may be provided as methods, systems, or computer program products. Therefore, the present application may 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 may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include 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 generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. 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 capable of directing a computer or other programmable data processing device to operate 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 A 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 instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified 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 modes, which are merely illustrative rather than 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 within the protection of 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.

2. The engine boost rationality diagnosis method according to claim 1, characterized in that: Methods for diagnosing whether a boost failure occurs based on intake pressure include: 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 engine throttle inlet pressure, 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 target boost pressure average value, and the actual engine intake flow reference value.

3. The engine boost rationality diagnosis method according to claim 2, characterized in that: The boost actuator opening standard threshold pct BoostActuatorLim Calculated by the following formula: Where, pct BoostActuatorBase is the boost actuator opening reference value, 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 excess air coefficient, dm Cylinder is the average value of the actual intake flow rate of the engine, p BoostDesird is the target boost pressure average value, dm CylinderBase It is the actual intake air flow reference value of the engine; and are the correction parameters obtained during bench calibration.

4. The engine boost rationality diagnosis method according to claim 3, characterized in that: Correction parameters obtained during bench calibration and The methods include: 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.

5. The engine boost rationality diagnosis method according to claim 3, characterized in that: If the average opening value of the boost actuator corresponding to the current working condition meets the standard threshold: It indicates that a rationality fault has occurred; 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.

6. The engine boost rationality diagnosis method according to claim 5, 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.

7. The engine boost rationality diagnosis method according to claim 6, 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 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; 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 r Adapt1 (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; In addition to the above, Adapt1 =r Adapt1 (z).

8. The engine boost rationality diagnosis method according to claim 1, characterized in that: Methods for diagnosing whether a boost fault occurs based on ignition efficiency include: 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 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.

9. The engine boost rationality diagnosis method according to claim 8, characterized in that: The boost actuator opening standard threshold pct BoostActuatorLim Calculated by the following formula: 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 rate of the engine, dm CylinderBase It is the actual intake air flow reference value of the engine; and are the correction parameters obtained during bench calibration.

10. The engine boost rationality diagnosis method according to claim 9, characterized in that: Correction parameters obtained during bench calibration and The methods include: 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.

11. The engine boost rationality diagnosis method according to claim 9, characterized in that: If the average opening value of the boost actuator corresponding to the current working condition and the standard threshold value meet one of the following conditions: (1) The throttle valve is fully open |pct BoostActuator -pct BoostActuatorLim |≥Δ2 (2) The throttle valve is not fully open This indicates a rationality failure; Where Δ2 is the ratio 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.

12. The engine boost rationality diagnosis method according to claim 11, 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 diagnosis of whether a boost fault occurs CNT3 and the number of times the ignition efficiency diagnosis of no fault occurs CNT4 are recorded and stored, and saved after the vehicle is powered off.

13. The engine boost rationality diagnosis method according to claim 12, 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 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 updated again; When the number of occurrences CNT3 is greater than the preset value, the vehicle mileage L2 exceeds the preset value, 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 updated again; In addition to the above, Adapt2 =r Adapt2 (z).

14. 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 13.

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