Wastegate valve fault diagnosis method, device, equipment and readable storage medium

Abstract

The present application provides a method, apparatus, device, and readable storage medium for diagnosing a wastegate valve fault. The method includes: if a turbocharger has a boost pressure fault when the engine is in an idle state, determining that a diagnostic prerequisite is not met; otherwise, determining that the diagnostic prerequisite is met; if the diagnostic prerequisite is met, then, when the engine is in any operating state, determining whether the wastegate valve has a stuck fault based on a first monitoring indicator and a second monitoring indicator, wherein the first monitoring indicator is used to feedback the pressure of the exhaust gas entering the turbine or the pressure of the air discharged by the compressor, and the second monitoring indicator is used to feedback the temperature of the exhaust gas entering the turbine or the temperature of the air discharged by the compressor. Through the present application, on the basis of eliminating interference factors in wastegate valve fault diagnosis, a comprehensive judgment is made by combining monitoring indicators of the two dimensions of pressure and temperature, thereby improving the diagnostic accuracy of wastegate valve stuck faults.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle fault diagnosis, and in particular to a method, device, equipment and readable storage medium for diagnosing a wastegate valve fault. Background Art

[0002] The wastegate valve is a key component in turbocharged engines, primarily controlling the turbocharger's boost pressure. When the engine operates under different operating conditions, the wastegate valve regulates the flow of exhaust gas into the turbine, ensuring the appropriate boost pressure range. This improves engine performance and fuel economy, while protecting the engine and turbocharger from damage caused by excessive pressure. A stuck wastegate valve can cause the turbocharger to overspeed and overheat, potentially damaging it. This can also affect engine combustion, leading to reduced fuel economy and power.

[0003] In existing technologies, some methods determine whether the wastegate valve is operating properly by monitoring the deviation between the boost pressure and the target boost pressure. When the boost pressure is detected to be continuously deviating from the target value, it is preliminarily determined that the wastegate valve may be faulty. Other technologies use various sensor data collected by the engine control unit, such as the intake pressure sensor and throttle position sensor, to construct an engine model through complex algorithms. The boost pressure is predicted based on the model and compared with the actual measured value to diagnose wastegate valve faults. Due to the complex and changeable vehicle driving conditions and the frequent fluctuations in parameters such as engine speed and load, existing solutions have difficulty distinguishing between a stuck wastegate valve fault and boost pressure abnormalities caused by other factors. Therefore, it is impossible to accurately diagnose whether the wastegate valve is stuck while the vehicle is driving. Summary of the Invention

[0004] The present application provides a wastegate valve fault diagnosis method, device, equipment and readable storage medium, which can solve the technical problem in the prior art of being unable to accurately diagnose whether the wastegate valve has a stuck fault.

[0005] In a first aspect, an embodiment of the present application provides a wastegate valve fault diagnosis method, the wastegate valve fault diagnosis method comprising:

[0006] If the turbocharger has a boost pressure fault when the engine is in idle condition, it is determined that the diagnostic prerequisite is not met; otherwise, it is determined that the diagnostic prerequisite is met;

[0007] If the diagnostic prerequisites are met, when the engine is in any operating condition, it is determined whether the exhaust bypass valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator. The first monitoring indicator is used to feedback the pressure of the exhaust gas entering the turbine or the pressure of the air discharged by the compressor, and the second monitoring indicator is used to feedback the temperature of the exhaust gas entering the turbine or the temperature of the air discharged by the compressor.

[0008] Furthermore, in one embodiment, the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator includes:

[0009] If the absolute value of the difference between the measured value of the pressure of the exhaust gas entering the turbine and the target value is greater than the first difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than the first rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0010] Furthermore, in one embodiment, after the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator, the method further includes:

[0011] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is greater than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is less than zero, then it is determined that the wastegate valve is stuck at a relatively small opening;

[0012] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is less than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0013] Furthermore, in one embodiment, the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator includes:

[0014] If the absolute value of the difference between the measured value of the ratio of the pressure of the air discharged by the compressor to the atmospheric pressure and the target value is greater than a second difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged by the compressor is greater than a second rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0015] Furthermore, in one embodiment, after the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator, the method further includes:

[0016] If the wastegate valve is determined to be stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then the wastegate valve is determined to be stuck at a relatively small opening.

[0017] If it is determined that the wastegate valve is stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0018] Furthermore, in one embodiment, the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator includes:

[0019] If the absolute value of the difference between the measured value of the pressure of the air discharged by the compressor and the target value is greater than the third difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged by the compressor is greater than the second rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0020] Furthermore, in one embodiment, after the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator, the method further includes:

[0021] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then it is determined that the wastegate valve is stuck at a relatively small opening.

[0022] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0023] In a second aspect, an embodiment of the present application further provides a wastegate valve fault diagnosis device, the wastegate valve fault diagnosis device comprising:

[0024] a first judgment module, configured to determine that a diagnostic prerequisite is not satisfied if a turbocharger has a boost pressure fault when the engine is in an idle state, and otherwise determine that the diagnostic prerequisite is satisfied;

[0025] The second judgment module is used to determine whether the exhaust bypass valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator when the engine is in any operating condition if the diagnostic prerequisite is met, wherein the first monitoring indicator is used to feedback the pressure of the exhaust gas entering the turbine or the pressure of the air discharged by the compressor, and the second monitoring indicator is used to feedback the temperature of the exhaust gas entering the turbine or the temperature of the air discharged by the compressor.

[0026] In a third aspect, an embodiment of the present application further provides an exhaust bypass valve fault diagnosis device, which includes a processor, a memory, and an exhaust bypass valve fault diagnosis program stored on the memory and executable by the processor, wherein when the exhaust bypass valve fault diagnosis program is executed by the processor, the steps of the above-mentioned exhaust bypass valve fault diagnosis method are implemented.

[0027] In a fourth aspect, an embodiment of the present application further provides a readable storage medium, on which a wastegate bypass valve fault diagnosis program is stored, wherein when the wastegate bypass valve fault diagnosis program is executed by a processor, the steps of the above-mentioned wastegate bypass valve fault diagnosis method are implemented.

[0028] In this application, if the turbocharger has a boost pressure fault when the engine is idling, it is determined that the diagnostic prerequisite is not met; otherwise, it is determined that the diagnostic prerequisite is met; if the diagnostic prerequisite is met, then when the engine is in any operating condition, the first monitoring indicator and the second monitoring indicator are used to determine whether the wastegate valve has a stuck fault, wherein the first monitoring indicator is used to feedback the pressure of the exhaust gas entering the turbine or the pressure of the air discharged by the compressor, and the second monitoring indicator is used to feedback the temperature of the exhaust gas entering the turbine or the temperature of the air discharged by the compressor. Through this application, on the basis of eliminating interference factors in wastegate valve fault diagnosis, a comprehensive judgment is made by combining monitoring indicators of the two dimensions of pressure and temperature, thereby improving the diagnostic accuracy of wastegate valve stuck faults during vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of a flow chart of a method for diagnosing a wastegate valve fault in one embodiment of the present application;

[0030] Figure 2 Schematic diagram of the working principle of the wastegate valve in the related art;

[0031] Figure 3 A schematic diagram showing the pressure condition of the exhaust gas entering the turbine when the bypass valve is stuck at a relatively large opening for experimental simulation;

[0032] Figure 4 This is a schematic diagram of the test simulating the temperature of the exhaust gas entering the turbine when the bypass valve is stuck at a large opening;

[0033] Figure 5 This is a schematic diagram of the pressure of the air discharged from the compressor when the bypass valve is stuck at a large opening;

[0034] Figure 6 This is a schematic diagram of the temperature of the air discharged from the compressor when the bypass valve is stuck at a large opening;

[0035] Figure 7 This is a schematic diagram of the functional modules of a wastegate valve fault diagnosis device in one embodiment of the present application;

[0036] Figure 8 This is a schematic diagram of the hardware structure of the exhaust bypass valve fault diagnosis device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0039] In a first aspect, an embodiment of the present application provides a method for diagnosing a wastegate valve fault.

[0040] Figure 1 FIG. 1 is a flow chart of a method for diagnosing a wastegate valve fault in an embodiment of the present application. Figure 2 A schematic diagram of the working principle of an exhaust gas bypass valve in related technology is shown.

[0041] Reference Figure 1 In one embodiment, a method for diagnosing a wastegate valve fault includes the following steps:

[0042] S1. If a turbocharger boost pressure fault occurs when the engine is in an idle state, it is determined that the diagnostic prerequisite is not met; otherwise, it is determined that the diagnostic prerequisite is met.

[0043] Reference Figure 2 The clean air that passes through the air filter enters the compressor, and the high-pressure air discharged from the compressor enters the engine through the intercooler. Part of the exhaust gas discharged by the engine enters the turbine to drive the turbine blades to rotate, and the other part passes through the exhaust bypass valve directly to the exhaust pipe. By adjusting the opening of the exhaust bypass valve, the ratio of exhaust gas entering the turbine and directly going to the exhaust pipe can be changed. When the amount of exhaust gas entering the turbine increases, the speed of the turbine blades increases, and the speed of the compressor blades connected to it also increases, and the engine intake volume increases.

[0044] Specifically, the wastegate valve opening is adjusted based on boost pressure, with the target value related to the engine operating conditions. When the engine is idling, the existing control logic sets the wastegate valve opening to zero, meaning that all exhaust gas enters the turbine. In addition to a stuck wastegate valve, turbocharger boost pressure failures during idling can also be caused by turbine failure, compressor failure, air filter blockage, intake manifold leaks, and exhaust leaks. These faults can interfere with the diagnosis of a stuck wastegate valve, reducing diagnostic accuracy.

[0045] In this embodiment, "there is no boost pressure failure in the turbocharger when the engine is in idle condition" is used as a prerequisite for diagnosing the wastegate valve stuck fault. This can eliminate factors that may interfere with the diagnosis of the wastegate valve stuck fault, thereby improving the diagnostic accuracy.

[0046] S2. If the diagnostic prerequisites are met, then when the engine is in any operating condition, it is determined whether the exhaust bypass valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator, wherein the first monitoring indicator is used to feedback the pressure of the exhaust gas entering the turbine or the pressure of the air discharged by the compressor, and the second monitoring indicator is used to feedback the temperature of the exhaust gas entering the turbine or the temperature of the air discharged by the compressor.

[0047] In this embodiment, if a wastegate valve is stuck under any engine operating condition, the pressure and temperature of the exhaust gas entering the turbine and the pressure and temperature of the air discharged from the compressor will significantly differ from the expected conditions corresponding to the current engine operating condition. Therefore, whether the wastegate valve is stuck can be determined based on whether there is a significant difference between the actual and expected conditions.

[0048] Specifically, the first monitoring indicator and the second monitoring indicator can be combined to form four optional diagnostic methods:

[0049] Determine whether the wastegate valve is stuck based on the pressure and temperature of the exhaust gas entering the turbine;

[0050] Determine whether the wastegate valve is stuck based on the pressure of the air discharged from the compressor and the temperature of the exhaust gas entering the turbine;

[0051] Determine whether the wastegate valve is stuck based on the pressure and temperature of the air discharged from the compressor;

[0052] Determine whether the wastegate valve is stuck based on the pressure of the exhaust gas entering the turbine and the temperature of the air discharged from the compressor.

[0053] In this embodiment, a comprehensive judgment is made based on monitoring indicators in two dimensions, namely pressure and temperature. This has a higher diagnostic accuracy than a single-dimensional judgment based on pressure or temperature.

[0054] Therefore, in this embodiment, if the turbocharger has a boost pressure fault when the engine is idling, the diagnostic precondition is determined to be unmet; otherwise, the diagnostic precondition is determined to be met. If the diagnostic precondition is met, then, under any engine operating condition, the presence of a stuck wastegate valve is determined based on a first monitoring indicator and a second monitoring indicator. The first monitoring indicator is used to provide feedback on the pressure of the exhaust gas entering the turbine or the pressure of the air discharged from the compressor, and the second monitoring indicator is used to provide feedback on the temperature of the exhaust gas entering the turbine or the temperature of the air discharged from the compressor. This embodiment eliminates interference factors in wastegate valve fault diagnosis and combines monitoring indicators from both pressure and temperature dimensions for a comprehensive assessment, thereby improving the diagnostic accuracy of a stuck wastegate valve fault while the vehicle is in motion.

[0055] Furthermore, in one embodiment, the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator includes:

[0056] If the absolute value of the difference between the measured value of the pressure of the exhaust gas entering the turbine and the target value is greater than the first difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than the first rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0057] Figure 3 The schematic diagram shows the pressure of the exhaust gas entering the turbine when the bypass valve is stuck at a large opening in the test simulation. Figure 4 A schematic diagram showing the temperature of the exhaust gas entering the turbine when the bypass valve is stuck at a large opening in the test simulation.

[0058] Reference Figure 3 and Figure 4 The exhaust gas pressure entering the turbine is shown as P3 in the figure, and the exhaust gas temperature entering the turbine is shown as T3. At full load and a torque point of 1200 rpm, the bypass valve opening was forced to control the opening to simulate a stuck condition. Under normal control logic, the bypass valve opening was 18%, and the measured P3 pressure was roughly consistent with the target value, approximately 310 kPa. The measured T3 temperature remained stable at 480°C. When the bypass valve opening was forced to 25%, causing the bypass valve to stick at a larger opening, the measured P3 pressure dropped rapidly from the target value to approximately 250 kPa, while the measured T3 temperature slowly increased to 590°C.

[0059] It can be observed that when the bypass valve is stuck, the pressure of the exhaust gas entering the turbine changes relatively rapidly and will reach a stable state quickly. In addition, the pressure of the exhaust gas entering the turbine usually has a calibrated target value in the bypass valve related control logic. The temperature of the exhaust gas entering the turbine changes relatively slowly and will reach a stable state slowly.

[0060] Therefore, this embodiment compares the absolute value of the difference between the measured value of the pressure of the exhaust gas entering the turbine and the target value with the first difference threshold in the pressure dimension, and compares the rate of change of the measured value of the temperature of the exhaust gas entering the turbine with the first rate of change threshold in the temperature dimension, which helps to quickly and accurately determine whether the bypass valve has a stuck fault.

[0061] For example, Figure 3 and Figure 4 In the example, when the bypass valve is stuck at a large opening, the absolute value of the difference between the measured value of the P3 pressure and the target value is approximately 60 kPa, and the change rate of the measured value of the T3 temperature within 5 seconds is approximately 40°C / 5s. The first difference threshold is set to 20 kPa, and the first change rate threshold is set to 10°C / 5s.

[0062] It should be noted that the target value of the pressure of the exhaust gas entering the turbine needs to change with the operating condition of the engine, and the first difference threshold and the first change rate threshold may not change with the operating condition of the engine.

[0063] It can be understood that the measured values ​​of pressure and temperature mentioned in this embodiment and the following embodiments need to be as close to the actual values ​​as possible to ensure the accuracy of diagnosis.

[0064] Optionally, the sampling value of the pressure sensor is corrected according to the ambient pressure to obtain the pressure measurement value, so that the pressure measurement value is closer to the true value, and the sampling value of the temperature sensor is corrected according to the ambient temperature to obtain the temperature measurement value, so that the temperature measurement value is closer to the true value.

[0065] Furthermore, in one embodiment, after the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator, the method further includes:

[0066] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is greater than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is less than zero, then it is determined that the wastegate valve is stuck at a relatively small opening;

[0067] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is less than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0068] Continue to refer Figure 3 and Figure 4It can be seen that when the exhaust bypass valve is stuck at a larger opening, the measured value of the pressure of the exhaust gas entering the turbine is less than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than zero. Correspondingly, when the exhaust bypass valve is stuck at a smaller opening, the measured value of the pressure of the exhaust gas entering the turbine is greater than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is less than zero.

[0069] Through this embodiment, after determining that the exhaust bypass valve has a stuck fault, the stuck position of the exhaust bypass valve is further determined based on the relationship between the measured value of the pressure of the exhaust gas entering the turbine and the target value and the sign of the measured value of the temperature of the exhaust gas entering the turbine, thereby providing more diagnostic information.

[0070] For example, in the case where the vehicle cannot be stopped for maintenance in time, the engine operating condition that is less affected by the current stuck position of the wastegate valve is preferably used.

[0071] Furthermore, in one embodiment, the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator includes:

[0072] If the absolute value of the difference between the measured value of the ratio of the pressure of the air discharged by the compressor to the atmospheric pressure and the target value is greater than a second difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged by the compressor is greater than a second rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0073] Figure 5 A schematic diagram showing the pressure of the air discharged from the compressor when the bypass valve is stuck at a relatively large opening in the test simulation; Figure 6 A schematic diagram showing the temperature of the air discharged from the compressor when the bypass valve is stuck at a large opening in the test simulation is shown.

[0074] Reference Figure 5 and Figure 6 The ratio of the compressor exhaust air pressure to atmospheric pressure is shown in the figure as the pressure ratio, and the compressor exhaust air temperature is shown in the figure as the compressor outlet temperature. At full load and a torque point of 1200 rpm, a stuck condition was simulated by forcibly controlling the bypass valve opening. Under normal control logic, the bypass valve opening was 18%, and the measured pressure ratio was essentially consistent with the target value, approximately 3.5. The measured compressor outlet temperature remained stable at 200°C. When the bypass valve opening was forced to 25%, causing the bypass valve to stick at a larger opening, the measured pressure ratio rapidly dropped from the target value to approximately 3, and the measured compressor outlet temperature slowly decreased to 170°C.

[0075] It can be observed that when the bypass valve is stuck, the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure changes relatively rapidly and will reach a stable state quickly. In addition, the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure usually has a calibrated target value in the bypass valve related control logic. The temperature of the air discharged from the compressor changes relatively slowly and will reach a stable state slowly.

[0076] Therefore, this embodiment compares the absolute value of the difference between the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure and the target value with the second difference threshold in the pressure dimension, and compares the rate of change of the measured value of the temperature of the air discharged from the compressor with the second rate of change threshold in the temperature dimension, which helps to quickly and accurately determine whether the bypass valve has a stuck fault.

[0077] Optionally, the pressure of the air discharged from the compressor may be the compressor outlet pressure or the intercooler inlet pressure, and the temperature of the air discharged from the compressor may be the compressor outlet temperature or the intercooler inlet temperature.

[0078] For example, Figure 5 and Figure 6 In the example, when the bypass valve is stuck at a large opening, the absolute value of the difference between the measured value of the pressure ratio and the target value is approximately 0.5, and the change rate of the measured value of the compressor outlet temperature within 5 seconds is approximately 10°C / 5s. The second difference threshold is set to 0.2, and the second change rate threshold is set to 5°C / 5s.

[0079] It should be noted that the target value of the ratio of the pressure of the air discharged by the compressor to the atmospheric pressure needs to change with the operating condition of the engine, while the second difference threshold and the second change rate threshold may not change with the operating condition of the engine.

[0080] Furthermore, in one embodiment, after the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator, the method further includes:

[0081] If the wastegate valve is determined to be stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then the wastegate valve is determined to be stuck at a relatively small opening.

[0082] If it is determined that the wastegate valve is stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0083] Continue to refer Figure 5 and Figure 6It can be seen that when the wastegate valve is stuck at a larger opening, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero. Correspondingly, when the wastegate valve is stuck at a smaller opening, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero.

[0084] Through this embodiment, after determining that the wastegate valve has a stuck fault, the stuck position of the wastegate valve is further determined based on the magnitude relationship between the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure and a target value and the sign of the measured value of the temperature of the air discharged from the compressor, thereby providing more diagnostic information.

[0085] Furthermore, in one embodiment, the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator includes:

[0086] If the absolute value of the difference between the measured value of the pressure of the air discharged by the compressor and the target value is greater than the third difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged by the compressor is greater than the second rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0087] It can be understood that within a single diagnostic cycle, the atmospheric pressure usually does not change significantly. Therefore, compared with the previous embodiment, this embodiment compares the absolute value of the difference between the measured value of the pressure of the air discharged by the compressor and the target value with the third difference threshold in the pressure dimension, and can also quickly and accurately determine whether the bypass valve has a stuck fault.

[0088] In particular, if the pressure of the air discharged from the compressor does not have a calibrated target value in the bypass valve related control logic, it is necessary to additionally calibrate the target value of the pressure of the air discharged from the compressor for diagnosis of the bypass valve sticking fault.

[0089] It should be noted that the target value of the pressure of the air discharged by the compressor needs to change with the operating condition of the engine, while the third difference threshold and the second change rate threshold may not change with the operating condition of the engine.

[0090] Furthermore, in one embodiment, after the step of determining whether the wastegate valve has a stuck fault based on the first monitoring indicator and the second monitoring indicator, the method further includes:

[0091] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then it is determined that the wastegate valve is stuck at a relatively small opening.

[0092] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0093] Through this embodiment, after determining that the wastegate valve has a stuck fault, the stuck position of the wastegate valve is further determined based on the relationship between the measured value of the pressure of the air discharged from the compressor and the target value and the sign of the measured value of the temperature of the air discharged from the compressor, thereby providing more diagnostic information.

[0094] In a second aspect, an embodiment of the present application further provides a wastegate valve fault diagnosis device.

[0095] Figure 7 A schematic diagram of the functional modules of a wastegate valve fault diagnosis device in one embodiment of the present application is shown.

[0096] Reference Figure 7 In one embodiment, the wastegate valve fault diagnosis device includes:

[0097] A first judgment module 10 is configured to determine that a diagnostic prerequisite is not satisfied if a turbocharger boost pressure fault occurs when the engine is in an idle state, and otherwise determine that the diagnostic prerequisite is satisfied;

[0098] The second judgment module 20 is used to judge whether there is a stuck fault in the exhaust bypass valve based on the first monitoring indicator and the second monitoring indicator when the engine is in any operating condition if the diagnostic prerequisite is met, wherein the first monitoring indicator is used to feedback the pressure of the exhaust gas entering the turbine or the pressure of the air discharged by the compressor, and the second monitoring indicator is used to feedback the temperature of the exhaust gas entering the turbine or the temperature of the air discharged by the compressor.

[0099] Furthermore, in one embodiment, the second judgment module 20 is configured to:

[0100] If the absolute value of the difference between the measured value of the pressure of the exhaust gas entering the turbine and the target value is greater than the first difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than the first rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0101] Furthermore, in one embodiment, the wastegate valve fault diagnosis device further includes a third judgment module 30, configured to:

[0102] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is greater than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is less than zero, then it is determined that the wastegate valve is stuck at a relatively small opening;

[0103] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is less than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0104] Furthermore, in one embodiment, the second judgment module 20 is configured to:

[0105] If the absolute value of the difference between the measured value of the ratio of the pressure of the air discharged by the compressor to the atmospheric pressure and the target value is greater than a second difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged by the compressor is greater than a second rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0106] Furthermore, in one embodiment, the wastegate valve fault diagnosis device further includes a third judgment module 30, configured to:

[0107] If the wastegate valve is determined to be stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then the wastegate valve is determined to be stuck at a relatively small opening.

[0108] If it is determined that the wastegate valve is stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0109] Furthermore, in one embodiment, the second judgment module 20 is configured to:

[0110] If the absolute value of the difference between the measured value of the pressure of the air discharged by the compressor and the target value is greater than the third difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged by the compressor is greater than the second rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

[0111] Furthermore, in one embodiment, the wastegate valve fault diagnosis device further includes a third judgment module 30, configured to:

[0112] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then it is determined that the wastegate valve is stuck at a relatively small opening.

[0113] If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

[0114] Among them, the functional implementation of each module in the above-mentioned exhaust bypass valve fault diagnosis device corresponds to the various steps in the above-mentioned exhaust bypass valve fault diagnosis method embodiment, and their functions and implementation processes are no longer repeated here.

[0115] In a third aspect, an embodiment of the present application provides a wastegate valve fault diagnosis device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0116] Figure 8 A schematic diagram of the hardware structure of the exhaust gas bypass valve fault diagnosis device involved in the embodiment of the present application is shown.

[0117] Reference Figure 8 In an embodiment of the present application, the exhaust bypass valve fault diagnosis device may include a processor, a memory, a communication interface, and a communication bus.

[0118] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0119] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the wastegate valve fault diagnosis device, as well as interfaces used to interconnect the wastegate valve fault diagnosis device with other devices (such as other computing devices or user devices). Physical interfaces can be Ethernet, fiber, or ATM interfaces; user devices can be displays or keyboards.

[0120] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0121] The processor may be a general-purpose processor that can invoke a wastegate valve fault diagnosis program stored in a memory and execute the wastegate valve fault diagnosis method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the wastegate valve fault diagnosis program is invoked can be referenced from the various embodiments of the wastegate valve fault diagnosis method of the present application and will not be further described here.

[0122] Those skilled in the art will understand that Figure 8 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0123] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.

[0124] The readable storage medium of the present application stores an exhaust bypass valve fault diagnosis program, wherein when the exhaust bypass valve fault diagnosis program is executed by the processor, the steps of the exhaust bypass valve fault diagnosis method as described above are implemented.

[0125] Among them, the method implemented when the exhaust bypass valve fault diagnosis program is executed can refer to the various embodiments of the exhaust bypass valve fault diagnosis method of the present application, and will not be repeated here.

[0126] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0127] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0128] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0129] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0130] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0131] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0132] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for diagnosing a wastegate valve fault, characterized in that: The wastegate valve fault diagnosis method includes: If the turbocharger has a boost pressure fault when the engine is in idle condition, it is determined that the diagnostic prerequisite is not met; otherwise, it is determined that the diagnostic prerequisite is met; When the engine is in any operating condition, if the diagnostic prerequisite is met, the absolute value of the difference between the measured value of the pressure of the exhaust gas entering the turbine and the target value is greater than a first difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than a first rate of change threshold, then it is determined that the wastegate valve has a stuck fault; If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is greater than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is less than zero, then it is determined that the wastegate valve is stuck at a relatively small opening; If it is determined that the wastegate valve is stuck, the measured value of the pressure of the exhaust gas entering the turbine is less than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than zero, then it is determined that the wastegate valve is stuck at a large opening.

2. A method for diagnosing a wastegate valve fault, characterized in that: The wastegate valve fault diagnosis method includes: If the turbocharger has a boost pressure fault when the engine is in idle condition, it is determined that the diagnostic prerequisite is not met; otherwise, it is determined that the diagnostic prerequisite is met; When the engine is in any operating condition, if the diagnostic prerequisite is met, the absolute value of the difference between the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure and the target value is greater than a second difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than a second rate of change threshold, then it is determined that the wastegate valve has a stuck fault; If the wastegate valve is determined to be stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then the wastegate valve is determined to be stuck at a relatively small opening. If it is determined that the wastegate valve is stuck, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

3. A method for diagnosing a wastegate valve fault, characterized in that: The wastegate valve fault diagnosis method includes: If the turbocharger has a boost pressure fault when the engine is in idle condition, it is determined that the diagnostic prerequisite is not met; otherwise, it is determined that the diagnostic prerequisite is met; When the engine is in any operating condition, if the diagnostic prerequisite is met, the absolute value of the difference between the measured value of the compressor exhaust air pressure and the target value is greater than the third difference threshold, and the absolute value of the rate of change of the measured value of the compressor exhaust air temperature is greater than the second rate of change threshold, then it is determined that the wastegate valve has a stuck fault; If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is greater than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero, then it is determined that the wastegate valve is stuck at a relatively small opening. If it is determined that the wastegate valve is stuck, the measured value of the pressure of the air discharged from the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero, then it is determined that the wastegate valve is stuck at a large opening.

4. A wastegate valve fault diagnosis device, characterized in that: The wastegate valve fault diagnosis device comprises: a first judgment module, configured to judge that a diagnostic prerequisite is not satisfied if a turbocharger has a boost pressure fault when the engine is in an idle state, and otherwise judge that the diagnostic prerequisite is satisfied; a second judgment module, configured to, when the engine is in any operating condition, determine that a stuck wastegate valve fault exists if a diagnostic prerequisite is met, namely, an absolute value of a difference between a measured value of the pressure of the exhaust gas entering the turbine and a target value is greater than a first difference threshold, and an absolute value of a rate of change of a measured value of the temperature of the exhaust gas entering the turbine is greater than a first rate of change threshold; The third judgment module is used to judge that the exhaust bypass valve is stuck at a smaller opening if it is judged that there is a stuck fault in the exhaust bypass valve, the measured value of the pressure of the exhaust gas entering the turbine is greater than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is less than zero; if it is judged that there is a stuck fault in the exhaust bypass valve, the measured value of the pressure of the exhaust gas entering the turbine is less than the target value, and the rate of change of the measured value of the temperature of the exhaust gas entering the turbine is greater than zero, then the exhaust bypass valve is judged to be stuck at a larger opening.

5. A wastegate valve fault diagnosis device, characterized in that: The wastegate valve fault diagnosis device comprises: a first judgment module, configured to judge that a diagnostic prerequisite is not satisfied if a turbocharger has a boost pressure fault when the engine is in an idle state, and otherwise judge that the diagnostic prerequisite is satisfied; a second judgment module, configured to, when the engine is in any operating condition, determine that a stuck wastegate valve fault exists if a diagnostic prerequisite is met, namely, the absolute value of the difference between a measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure and a target value is greater than a second difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than a second rate of change threshold; The third judgment module is configured to determine that the wastegate valve is stuck at a relatively small opening if, when determining that the wastegate valve has a stuck fault, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is greater than a target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero; and to determine that the wastegate valve is stuck at a relatively large opening if, when determining that the wastegate valve has a stuck fault, the measured value of the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is less than a target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero.

6. A wastegate valve fault diagnosis device, characterized in that: The wastegate valve fault diagnosis device comprises: a first judgment module, configured to judge that a diagnostic prerequisite is not satisfied if a turbocharger has a boost pressure fault when the engine is in an idle state, and otherwise judge that the diagnostic prerequisite is satisfied; a second judgment module, configured to, when the engine is in any operating condition, determine that a stuck fault exists in the wastegate valve if a diagnostic prerequisite is met, namely, the absolute value of the difference between the measured value of the pressure of the air discharged from the compressor and the target value is greater than a third difference threshold, and the absolute value of the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than a second rate of change threshold; The third judgment module is configured to determine that the wastegate valve is stuck at a relatively small opening if, when it is determined that the wastegate valve has a stuck fault, the measured value of the pressure of the air discharged from the compressor is greater than a target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is greater than zero; and to determine that the wastegate valve is stuck at a relatively large opening if, when it is determined that the wastegate valve has a stuck fault, the measured value of the pressure of the air discharged from the compressor is less than a target value, and the rate of change of the measured value of the temperature of the air discharged from the compressor is less than zero.

7. A wastegate valve fault diagnosis device, characterized in that: The exhaust bypass valve fault diagnosis device includes a processor, a memory, and an exhaust bypass valve fault diagnosis program stored in the memory and executable by the processor, wherein when the exhaust bypass valve fault diagnosis program is executed by the processor, the steps of the exhaust bypass valve fault diagnosis method as described in any one of claims 1 to 3 are implemented.

8. A readable storage medium, characterized in that: The readable storage medium stores a wastegate valve fault diagnosis program, wherein when the wastegate valve fault diagnosis program is executed by the processor, the steps of the wastegate valve fault diagnosis method according to any one of claims 1 to 3 are implemented.

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