Waste gas bypass valve fault diagnosis method, device and equipment and readable storage medium

Abstract

The invention provides a waste gas bypass valve fault diagnosis method, device and equipment and a readable storage medium. The method comprises the steps that if an engine is in an idling working condition and a turbocharger has a supercharging pressure fault, it is judged that diagnosis preconditions are not met, and otherwise, it is judged that the diagnosis preconditions are met; if the diagnosis precondition is met, whether the waste gas bypass valve has a clamping stagnation fault or not is judged according to a first monitoring index and a second monitoring index when the engine is in any working condition, the first monitoring index is used for feeding back the pressure condition of waste gas entering a turbine or the pressure condition of air exhausted by a gas compressor, and the second monitoring index is used for feeding back the pressure condition of waste gas entering the turbine or the pressure condition of air exhausted by the gas compressor; the second monitoring index is used for feeding back the temperature condition of waste gas entering the turbine or the temperature condition of air exhausted by the air compressor. According to the application, on the basis of eliminating interference factors of waste gas bypass valve fault diagnosis, comprehensive judgment is carried out by combining monitoring indexes of two dimensions of pressure and temperature, so that the diagnosis accuracy of the clamping stagnation fault of the waste gas bypass valve is improved.

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 a turbocharged engine. Its main function is to control the boost pressure of the turbocharger. When the engine is running under different operating conditions, the wastegate valve adjusts the exhaust gas flow entering the turbine to ensure that the boost pressure is within the appropriate range, thereby improving the engine's power performance and fuel economy, and protecting the engine and turbocharger from damage caused by excessive pressure. When the wastegate valve is stuck, it will cause the turbocharger to overspeed and overheat, resulting in damage, and affect engine combustion, resulting in poor economy and power.

[0003] In the prior art, some methods determine whether the wastegate valve is working properly by monitoring the deviation between the boost pressure and the target boost pressure. When it is detected that the boost pressure continues to deviate from the target value, it is preliminarily determined that the wastegate valve may be faulty. Some other technologies use various sensor data collected by the engine control unit, such as the intake pressure sensor, throttle position sensor and other data, to build an engine model through complex algorithms, predict the boost pressure based on the model and compare it with the actual measured value to diagnose the failure of the wastegate valve. Due to the complex and changeable vehicle driving conditions, and the frequent fluctuations in parameters such as engine speed and load, it is difficult for existing solutions to distinguish between the abnormal boost pressure caused by the stuck fault of the wastegate valve and other factors, and it is impossible to accurately diagnose whether the wastegate valve has a stuck fault during vehicle driving. Summary of the invention

[0004] The present application provides an exhaust bypass valve fault diagnosis method, device, equipment and readable storage medium, which can solve the technical problem in the prior art that it is impossible to accurately diagnose whether the exhaust bypass valve has a stuck fault.

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

[0006] If there is a boost pressure fault in the turbocharger when the engine is in an idle condition, it is judged that the diagnostic prerequisite is not met, otherwise it is judged 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, 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 from 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 from the compressor.

[0008] Further, in one embodiment, the step of determining whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises:

[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 according to the first monitoring index and the second monitoring index, 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 larger opening.

[0013] Further, in one embodiment, the step of determining whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises:

[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 the 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 the 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 according to the first monitoring index and the second monitoring index, the method further includes:

[0016] If it is determined 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 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;

[0017] If it is determined that the exhaust bypass valve has a stuck fault, the measured value of the ratio of the pressure of the air discharged by 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 by the compressor is less than zero, then it is determined that the exhaust bypass valve is stuck at a larger opening.

[0018] Further, in one embodiment, the step of determining whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises:

[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 change rate of the measured value of the temperature of the air discharged by the compressor is greater than the second change rate 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 according to the first monitoring index and the second monitoring index, 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 waste gas bypass valve has a stuck fault, the measured value of the pressure of the air discharged by the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged by the compressor is less than zero, then it is determined that the waste gas bypass 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 is used to judge that the diagnosis prerequisite is not met if there is a boost pressure fault in the turbocharger when the engine is in an idle condition, and otherwise judge that the diagnosis prerequisite is met;

[0025] The second judgment module is used to judge whether the exhaust bypass valve has a stuck fault based on the first monitoring index and the second monitoring index when the engine is in any operating condition if the diagnostic prerequisite is met, wherein the first monitoring index 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 index 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 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 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 waste gas bypass valve fault diagnosis program is stored, wherein when the waste gas bypass valve fault diagnosis program is executed by a processor, the steps of the above-mentioned waste gas bypass valve fault diagnosis method are implemented.

[0028] In this application, if the turbocharger has a boost pressure fault when the engine is in an idle condition, it is judged that the diagnostic prerequisite is not met, otherwise it is judged that the diagnostic prerequisite is met; if the diagnostic prerequisite is met, then when the engine is in any condition, it is judged 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. Through this application, on the basis of eliminating the interference factors of the exhaust bypass valve fault diagnosis, the monitoring indicators of the two dimensions of pressure and temperature are combined for comprehensive judgment, thereby improving the diagnostic accuracy of the exhaust bypass valve stuck fault during vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0030] Figure 2 It is a schematic diagram of the working principle of the waste gas bypass valve in the related art;

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

[0032] Figure 4 A schematic diagram for testing and simulating the temperature of the exhaust gas entering the turbine when the bypass valve is stuck at a relatively large opening;

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

[0034] Figure 6 A schematic diagram for simulating the temperature of the air discharged from the compressor when the bypass valve is stuck at a relatively 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 solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, 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 the present application clearer, the implementation methods of the present 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 the related art is shown.

[0041] Reference Figure 1 In one embodiment, the wastegate valve fault diagnosis method comprises the following steps:

[0042] S1. If there is a boost pressure fault in the turbocharger when the engine is in an idle condition, 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 accordingly, and the engine intake volume increases.

[0044] Specifically, the opening of the wastegate valve is regulated based on the boost pressure, and the target value of the boost pressure is related to the engine operating conditions. When the engine is in an idle condition, in the existing control logic, the opening of the wastegate valve is fixed to zero, that is, all the exhaust gas enters the turbine. When the engine is in an idle condition, the reason for the turbocharger to have a boost pressure failure may be a turbine failure, a compressor failure, an air filter blockage, an intake pipe leakage, an exhaust leakage, etc. in addition to the wastegate valve stuck failure. These faults will interfere with the diagnosis of the wastegate valve stuck failure and reduce the accuracy of the diagnosis.

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

[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 from 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 from the compressor.

[0047] In this embodiment, when the engine is in any operating condition, if the wastegate valve has a stuck fault, the pressure and temperature of the exhaust gas entering the turbine and the pressure and temperature of the air discharged by the compressor will be significantly different from the expected conditions corresponding to the current engine operating condition. Therefore, it can be determined whether the wastegate valve has a stuck fault based on whether the actual condition is significantly different from the expected condition.

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

[0049] Determine whether the wastegate valve is stuck according to 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 waste gas entering the turbine;

[0051] Determine whether the waste gas bypass valve has a stuck fault based on the pressure and temperature of the air discharged from the compressor;

[0052] The pressure of the exhaust gas entering the turbine and the temperature of the air discharged from the compressor are used to determine whether the exhaust bypass valve is stuck.

[0053] In this embodiment, a comprehensive judgment is made through monitoring indicators in two dimensions, namely, pressure and temperature. Compared with single-dimensional judgment of pressure or temperature, the diagnostic accuracy is higher.

[0054] Therefore, in this embodiment, if the turbocharger has a boost pressure fault when the engine is in an idle condition, it is judged that the diagnostic prerequisite is not met, otherwise it is judged that the diagnostic prerequisite is met; if the diagnostic prerequisite is met, then when the engine is in any condition, it is judged whether the wastegate valve has a stuck fault according to the first monitoring indicator and the second monitoring indicator, wherein the first monitoring indicator is used to feedback the pressure of the wastegate 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 wastegate entering the turbine or the temperature of the air discharged by the compressor. Through this embodiment, on the basis of eliminating the interference factors of the wastegate valve fault diagnosis, a comprehensive judgment is made by combining the monitoring indicators of the two dimensions of pressure and temperature, thereby improving the diagnostic accuracy of the wastegate valve stuck fault during vehicle driving.

[0055] Further, in one embodiment, the step of determining whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises:

[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 relatively 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 relatively large opening in the test simulation.

[0058] Reference Figure 3 and Figure 4 , the pressure of the exhaust gas entering the turbine is P3 pressure in the figure, and the temperature of the exhaust gas entering the turbine is T3 temperature in the figure. Under the full load condition of 1200rpm torque point, the jamming condition is simulated by controlling the bypass valve opening. Under normal control logic, the bypass valve opening is 18%, and the measured value of P3 pressure is basically consistent with the target value, which is about 310kPa. The measured value of T3 temperature is stable at 480℃. When the bypass valve opening is controlled to 25%, the measured value of P3 pressure rapidly decreases and deviates from the target value, which is about 250kPa, and the measured value of T3 temperature slowly increases to 590℃.

[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 reaches 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 reaches 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 When the bypass valve is stuck at a larger 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 embodiments below need to be as close to the actual values ​​as possible to ensure the accuracy of diagnosis.

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

[0065] Furthermore, in one embodiment, after the step of determining whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index, 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 larger 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] Further, in one embodiment, the step of determining whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises:

[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 the 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 the 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 condition 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 relatively large opening in the test simulation.

[0074] Reference Figure 5 and Figure 6 , the ratio of the pressure of the air discharged from the compressor to the atmospheric pressure is the pressure ratio in the figure, and the temperature of the air discharged from the compressor is the compressor outlet temperature in the figure. Under the torque point 1200rpm full load condition, the jamming situation is simulated by forcibly controlling the bypass valve opening. Under normal control logic, the bypass valve opening is 18%, and the measured value of the pressure ratio is basically consistent with the target value, which is about 3.5. The measured value of the compressor outlet temperature is stable at 200℃. When the bypass valve opening is forcibly controlled to 25%, the measured value of the pressure ratio rapidly decreases and deviates from the target value, which is about 3. The measured value of the compressor outlet temperature slowly decreases to 170℃.

[0075] It can be observed that when the bypass valve is stuck, the ratio of the pressure of the air discharged by the compressor to the atmospheric pressure changes rapidly and reaches a stable state quickly. In addition, the ratio of the pressure of the air discharged by 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 by the compressor changes slowly and reaches 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 When the bypass valve is stuck at a larger 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, and 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 according to the first monitoring index and the second monitoring index, the method further includes:

[0081] If it is determined 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 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;

[0082] If it is determined that the exhaust bypass valve has a stuck fault, the measured value of the ratio of the pressure of the air discharged by 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 by the compressor is less than zero, then it is determined that the exhaust bypass valve is stuck at a larger opening.

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

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

[0085] Further, in one embodiment, the step of determining whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises:

[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 change rate of the measured value of the temperature of the air discharged by the compressor is greater than the second change rate 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, in the pressure dimension, 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 compared with the third difference threshold value, so as to quickly and accurately determine whether the bypass valve has a stuck fault.

[0088] In particular, if there is no calibrated target value for the pressure of the air discharged from the compressor in the bypass valve related control logic, it is necessary to additionally calibrate the target value for the pressure of the air discharged from the compressor for the 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, and 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 according to the first monitoring index and the second monitoring index, 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 waste gas bypass valve has a stuck fault, the measured value of the pressure of the air discharged by the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged by the compressor is less than zero, then it is determined that the waste gas bypass valve is stuck at a large opening.

[0093] 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 air exhausted by the compressor and the target value and the sign of the measured value of the temperature of the air exhausted by the compressor, thereby providing more diagnostic information.

[0094] In a second aspect, an embodiment of the present application also 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 comprises:

[0097] The first judgment module 10 is used to judge that the diagnosis prerequisite is not met if there is a boost pressure fault in the turbocharger when the engine is in an idle condition, and otherwise judge that the diagnosis prerequisite is met;

[0098] The second judgment module 20 is used to judge whether there is a stuck fault in the exhaust bypass valve according to the first monitoring index and the second monitoring index when the engine is in any operating condition if the diagnostic prerequisite is met, wherein the first monitoring index 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 index 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 determination module 20 is used 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, which is used 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 larger opening.

[0104] Furthermore, in one embodiment, the second determination module 20 is used 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 the 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 the 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, which is used to:

[0107] If it is determined 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 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;

[0108] If it is determined that the exhaust bypass valve has a stuck fault, the measured value of the ratio of the pressure of the air discharged by 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 by the compressor is less than zero, then it is determined that the exhaust bypass valve is stuck at a larger opening.

[0109] Furthermore, in one embodiment, the second determination module 20 is used 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 change rate of the measured value of the temperature of the air discharged by the compressor is greater than the second change rate 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, which is used 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 waste gas bypass valve has a stuck fault, the measured value of the pressure of the air discharged by the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged by the compressor is less than zero, then it is determined that the waste gas bypass 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 its 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 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, the memory, and the communication interface.

[0119] The communication interface includes an input / output (I / O) interface, a physical interface, and a logical interface, etc., which are used to interconnect the devices inside the exhaust bypass valve fault diagnosis device, and an interface used to interconnect the exhaust bypass valve fault diagnosis device with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[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 processor, and the general processor may call the exhaust bypass valve fault diagnosis program stored in the memory and execute the exhaust bypass valve fault diagnosis method provided in the embodiment of the present application. For example, the general processor may be a central processing unit (CPU). The method executed when the exhaust bypass valve fault diagnosis program is called may refer to the various embodiments of the exhaust bypass valve fault diagnosis method of the present application, which will not be described in detail here.

[0122] Those skilled in the art will understand that Figure 8 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[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 a 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 only for description 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 the present 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 "first", "second" and "third" to different types.

[0128] In the description of the embodiments of the present application, "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 the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[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; the “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 that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed 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 a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially 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, disk, CD) as described above, and includes a number of instructions for 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 are not intended to 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 comprises: If there is a boost pressure fault in the turbocharger when the engine is in an idle condition, it is judged that the diagnostic prerequisite is not met, otherwise it is judged that the diagnostic prerequisite is met; 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, 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 from 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 from the compressor.

2. The method for diagnosing wastegate valve failure according to claim 1, characterized in that: The step of judging whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises: 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.

3. The method for diagnosing wastegate valve failure as claimed in claim 2, characterized in that: After the step of judging whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index, the method further includes: 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 larger opening.

4. The method for diagnosing wastegate valve failure according to claim 1, characterized in that: The step of judging whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises: 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 the 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 the second rate of change threshold, it is determined that the exhaust bypass valve has a stuck fault.

5. The method for diagnosing wastegate valve failure as claimed in claim 4, characterized in that: After the step of judging whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index, the method further includes: If it is determined 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 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 exhaust bypass valve has a stuck fault, the measured value of the ratio of the pressure of the air discharged by 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 by the compressor is less than zero, then it is determined that the exhaust bypass valve is stuck at a larger opening.

6. The method for diagnosing wastegate valve failure as claimed in claim 1, characterized in that: The step of judging whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index comprises: 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 change rate of the measured value of the temperature of the air discharged by the compressor is greater than the second change rate threshold, it is determined that the exhaust bypass valve has a stuck fault.

7. The method for diagnosing wastegate valve failure as claimed in claim 6, characterized in that: After the step of judging whether the wastegate valve has a stuck fault according to the first monitoring index and the second monitoring index, the method further includes: 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 waste gas bypass valve has a stuck fault, the measured value of the pressure of the air discharged by the compressor is less than the target value, and the rate of change of the measured value of the temperature of the air discharged by the compressor is less than zero, then it is determined that the waste gas bypass valve is stuck at a large opening.

8. A wastegate valve fault diagnosis device, characterized in that: The wastegate valve fault diagnosis device comprises: A first judgment module is used to judge that the diagnostic prerequisite is not met if there is a boost pressure fault in the turbocharger when the engine is in an idle condition, and otherwise judge that the diagnostic prerequisite is met; The second judgment module is used to judge whether the exhaust bypass valve has a stuck fault based on the first monitoring index and the second monitoring index when the engine is in any operating condition if the diagnostic prerequisite is met, wherein the first monitoring index 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 index is used to feedback the temperature of the exhaust gas entering the turbine or the temperature of the air discharged by the compressor.

9. 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 7 are implemented.

10. 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 a processor, the steps of the wastegate valve fault diagnosis method as described in any one of claims 1 to 7 are implemented.

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