Self-adaptive correction method for valve flow characteristics, medium and controller

Abstract

The invention belongs to the technical field of valve detection, and particularly relates to a self-adaptive correction method for valve flow characteristics, which comprises the following steps of: when it is confirmed that a valve is aged, entering a cyclic correction mode: after a flow characteristic curve is corrected every time, obtaining a verification value of a characteristic quantity according to a self-adaptive characteristic working condition of the corrected flow characteristic curve, calculating a deviation value between the verification value of the characteristic quantity and a standard value of the characteristic quantity until the deviation value is smaller than a deviation threshold value; the self-adaptive characteristic working condition refers to the working condition that the operation state is abnormal than that of the valve which is not aged due to aging of the valve. Based on the correction method provided by the invention, the invention also correspondingly provides a computer readable storage medium and a controller. According to the method, aging can be accurately diagnosed by operating the self-adaptive characteristic working condition, the flow characteristic curve is accurately corrected, and the correction precision of the valve flow characteristics is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of valve detection, and in particular relates to a self-adaptive correction method, a medium and a controller for valve flow characteristics. Background Art

[0002] In order to optimize fuel consumption, EGR (Exhaust Gas Recirculation) technology is widely used in fuel vehicles or hybrid vehicles. The EGR valve is the core component of EGR technology, and the flow characteristics of the EGR valve have an important impact on the combustion performance of the engine.

[0003] The flow characteristics of the EGR valve will be calibrated before leaving the factory, and the EMS (Engine Management System) will calculate the intake volume based on the flow characteristics of the EGR valve. However, as the vehicle is used, pollutants in the emissions gradually deposit near the valve body, the EGR valve gradually ages, and the flow characteristics of the EGR valve will continue to change. Its actual flow characteristics will not match the calibrated flow characteristics, which will cause the calculated value of the effective intake volume entering the cylinder to be too small, resulting in a seriously lean mixture, which in turn leads to worsened engine combustion, and ultimately causes the engine to shake, misfire, or even stall. Summary of the invention

[0004] The present application provides a method for adaptively correcting valve flow characteristics to solve the technical problem of flow characteristic distortion caused by valve aging.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for adaptively correcting valve flow characteristics comprises the following steps:

[0007] When the valve is diagnosed as aging, enter the cycle correction mode:

[0008] After each correction of the flow characteristic curve is completed, the adaptive characteristic working condition is entered according to the corrected flow characteristic curve to obtain the calibration value of the characteristic quantity, and the deviation between the calibration value of the characteristic quantity and the standard value of the characteristic quantity is calculated until the deviation is less than the deviation threshold;

[0009] The adaptive characteristic working condition refers to the working condition where the operating state is abnormal due to valve aging compared to the working condition where the valve is not aged.

[0010] The present invention corrects the flow characteristic curve through a cyclic correction mode. Each time a correction is completed, an adaptive characteristic working condition is run to check whether the corrected flow characteristic curve meets the standard, that is, the deviation is less than the deviation threshold, thereby achieving the flow characteristic curve correction based on the actual valve aging state of an individual vehicle.

[0011] Furthermore, when the aging detection trigger condition is met, the adaptive characteristic working condition is entered, the verification value of the characteristic quantity under the adaptive characteristic working condition is obtained, and whether aging occurs is determined based on the deviation between the verification value of the characteristic quantity and the standard value of the characteristic quantity.

[0012] Diagnosing aging by running adaptive characteristic conditions is more accurate than simply judging whether the valve is aged by the accumulated usage time of the valve in the prior art. It is more in line with the actual aging condition of the valve, and the degree of valve aging can be judged to a certain extent by the size of the deviation.

[0013] Furthermore, the aging detection trigger condition is that the accumulated fuel consumption and the engine running time exceed corresponding trigger calibration amounts respectively.

[0014] Aging detection can be automatically triggered through the aging detection trigger conditions. The accumulated fuel consumption and engine running time directly affect the accumulated amount of emissions. When both exceed their respective trigger calibration quantities, the aging detection is triggered to achieve targeted results and avoid frequent triggering that reduces user experience.

[0015] Furthermore, the accumulated mileage is divided into different levels, and a corresponding trigger calibration amount is set for the accumulated mileage of each level.

[0016] The accumulated mileage increases with the use time of the vehicle, and the accumulated fuel consumption and engine running time also increase accordingly. Therefore, different trigger calibration quantities are set according to the accumulated mileage level, and the trigger calibration quantity also increases with the accumulated mileage. For example, the accumulated mileage of 0 to 100 kilometers is level one, the trigger calibration quantity of accumulated fuel consumption is a1, and the trigger calibration quantity of engine running time is b1; the accumulated mileage of 100 to 200 kilometers is level two, the trigger calibration quantity of accumulated fuel consumption is a2 (a2>a1), and the trigger calibration quantity of engine running time is b2 (b2>b1); when the accumulated mileage reaches level two, the accumulated fuel consumption and engine running time are compared with the corresponding trigger calibration quantities a2 and b2 respectively.

[0017] Furthermore, the characteristic quantities include charging model characteristic quantities, knock model characteristic quantities and fuel self-learning characteristic quantities.

[0018] The present invention adopts the charging model characteristic quantity, the knock model characteristic quantity and the fuel self-learning characteristic quantity to jointly characterize the valve aging phenomenon, and can accurately diagnose the valve aging. The three are indispensable, otherwise it will be impossible to rule out the abnormal operation of the engine caused by other reasons.

[0019] Furthermore, the charging model characteristic quantity includes the intake volume difference between the P charging volume and the throttle valve intake volume; the P charging volume refers to the intake volume calculated based on the pressure of the intake manifold pressure sensor; the throttle valve intake volume refers to the intake volume calculated based on the throttle valve opening.

[0020] Furthermore, the knock model characteristic quantities include an ignition angle correction value, an engine speed acceleration signal, and an engine speed fluctuation signal.

[0021] Furthermore, the fuel self-learning characteristic quantity includes a fuel self-learning correction coefficient.

[0022] Furthermore, the standard value of the characteristic quantity is obtained in the following manner: when a new vehicle is started for the first time, it enters an adaptive characteristic operating condition, and the value of the characteristic quantity under the adaptive characteristic operating condition is obtained as the standard value.

[0023] When a new car is started for the first time, it is obvious that the valve has not aged. At this time, the actual flow characteristic curve of the valve is basically consistent with the flow characteristic curve calibrated at the factory. According to the calibrated flow characteristic curve, the adaptive characteristic working condition is entered to obtain the characteristic quantity of the vehicle. Compared with the standard value of the characteristic quantity sampled and calibrated for the vehicle before leaving the factory, it is more accurate.

[0024] Furthermore, the operating conditions of the adaptive characteristic operating condition include a calibrated engine speed, a calibrated engine torque and a calibrated EGR rate.

[0025] The adaptive characteristic condition operates according to the calibrated engine speed, calibrated engine torque and calibrated EGR rate. Different models of vehicles need to be calibrated for the operating conditions of the adaptive characteristic condition. For economic considerations, sampling calibration is sufficient for the same model of vehicles.

[0026] The present invention also provides a computer-readable storage medium, wherein at least one instruction is stored in the storage medium, and the instruction is loaded and executed by a processor to implement the above-mentioned method for adaptively correcting valve flow characteristics.

[0027] The present invention also provides a controller, comprising a diagnosis unit and a correction unit;

[0028] The diagnostic unit is used to diagnose whether the valve is aged;

[0029] The correction unit is used to start the cyclic correction mode when the valve aging is confirmed:

[0030] After each correction of the flow characteristic curve is completed, the adaptive characteristic working condition is entered to obtain the verification value of the characteristic quantity, and the deviation between the verification value of the characteristic quantity and the standard value of the characteristic quantity is calculated until the deviation is less than the deviation threshold; the adaptive characteristic working condition refers to the working condition where the operating state is abnormal due to valve aging compared to the condition where the valve is not aged.

[0031] Furthermore, it also includes an autonomous calibration module, which is used to inquire the user whether to enter the adaptive characteristic working condition to calibrate the standard value of the characteristic quantity of the vehicle when the new car is started for the first time. If so, the adaptive characteristic working condition is started and the value of the characteristic quantity under the adaptive characteristic working condition is obtained as the standard value.

[0032] The present invention can accurately diagnose aging by running adaptive characteristic working conditions, and accurately correct the flow characteristic curve, thereby improving the correction accuracy of the valve flow characteristics. The present invention can automatically trigger aging detection and perform flow characteristic correction during the use of the vehicle to maintain a good combustion state of the engine, without the need for active maintenance by the user, thereby improving the vehicle experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a flowchart of the cycle correction mode in this specific implementation mode.

[0035] Figure 2 It is a flow chart of valve aging diagnosis in this specific implementation method. DETAILED DESCRIPTION

[0036] The flow characteristics of a valve refer to the relationship between the valve opening and the flow rate of the controlled medium flowing through the valve. In fuel vehicles or hybrid vehicles, the flow characteristics of the EGR valve will affect the effective air intake of the cylinder.

[0037] Since the air intake point of the EGR valve is at the exhaust end, and the exhaust often contains a large amount of particulate matter and incompletely burned gaseous pollutants, these substances enter the cooling unit through the pipeline and are cooled, and then finally enter the intake system through the EGR valve. The opening of the EGR valve is used to control the exhaust gas flow through the pipeline. Various particulate pollutants in the exhaust gas will form carbon deposits or other colloids that accumulate near the valve body after passing through the valve body for many years, causing the flow through the valve body to change significantly with the aging process.

[0038] The flow characteristics before aging do not match the actual flow characteristics, that is, the flow characteristics lose their authenticity. If the opening of the EGR valve is controlled according to the flow characteristics before aging, the calculated value of the effective intake volume entering the cylinder will be too small, resulting in a seriously lean mixture, which in turn leads to deterioration of engine combustion and ultimately causes the engine to shake, misfire or even stall.

[0039] In order to solve the technical problem of flow characteristic distortion caused by valve aging, the present invention provides an adaptive correction method for valve flow characteristics, which accurately diagnoses aging by running adaptive characteristic conditions and accurately corrects the flow characteristic curve, thereby improving the correction accuracy of valve flow characteristics.

[0040] The method for adaptively correcting valve flow characteristics provided by the present invention can be applied to various types of valves. This specific implementation is described by taking an EGR valve as an example, and is described in detail below in conjunction with the accompanying drawings and embodiments.

[0041] Example 1

[0042] refer to Figure 1 As shown, this embodiment provides a method for adaptively correcting valve flow characteristics, comprising the following steps:

[0043] When the valve is diagnosed as aging, enter the cycle correction mode:

[0044] After each correction of the flow characteristic curve is completed, the adaptive characteristic working condition is entered according to the corrected flow characteristic curve to obtain the calibration value of the characteristic quantity, and the deviation between the calibration value of the characteristic quantity and the standard value of the characteristic quantity is calculated until the deviation is less than the deviation threshold;

[0045] The adaptive characteristic operating condition refers to an operating condition in which the operating state is abnormal due to valve aging compared to a condition in which the valve has not been aged.

[0046] This embodiment corrects the flow characteristic curve through a cyclic correction mode. Each time a correction is completed, the adaptive characteristic working condition is run to check whether the corrected flow characteristic curve meets the standard, that is, the deviation is less than the deviation threshold, so as to correct the flow characteristic curve according to the actual valve aging status of the individual vehicle.

[0047] In this embodiment, the characteristic quantities include charging model characteristic quantities, knock model characteristic quantities and fuel self-learning characteristic quantities.

[0048] This embodiment uses the charging model characteristic quantity, the knock model characteristic quantity and the fuel self-learning characteristic quantity to jointly characterize the valve aging phenomenon, and can accurately diagnose valve aging. All three are indispensable, otherwise it will be impossible to rule out the abnormal operation of the engine caused by other reasons.

[0049] In this embodiment, the inflation model characteristic quantity includes the intake volume difference between the P inflation volume and the throttle valve intake volume; the P inflation volume refers to the intake volume calculated based on the pressure of the intake manifold pressure sensor; the throttle valve intake volume refers to the intake volume calculated based on the throttle valve opening.

[0050] In this embodiment, the knock model characteristic quantities include an ignition angle correction value, an engine speed acceleration signal, and an engine speed fluctuation signal.

[0051] In this embodiment, the fuel self-learning characteristic quantity includes a fuel self-learning correction coefficient.

[0052] The check values ​​of the above-mentioned characteristic quantities are compared with the standard values ​​of the corresponding characteristic quantities. When they are all less than the deviation threshold, it means that the re-established relationship between valve opening and flow, that is, the corrected flow characteristic curve, can ensure the normal operation of the engine.

[0053] Example 2

[0054] This implementation automatically performs diagnosis based on the aging detection trigger conditions, without the need for the user to actively perform diagnosis.

[0055] refer to Figure 2 As shown, when the aging detection trigger condition is met, the adaptive characteristic working condition is entered, the verification value of the characteristic quantity under the adaptive characteristic working condition is obtained, and whether aging occurs is determined based on the deviation between the verification value of the characteristic quantity and the standard value of the characteristic quantity.

[0056] In this embodiment, the aging detection trigger condition is that the cumulative fuel consumption and the engine running time exceed the corresponding trigger calibration amount respectively.

[0057] Aging detection can be automatically triggered through the aging detection trigger conditions. The accumulated fuel consumption and engine running time directly affect the accumulated amount of emissions. When both exceed their respective trigger calibration quantities, the aging detection is triggered to achieve targeted results and avoid frequent triggering that reduces user experience.

[0058] In this embodiment, the accumulated mileage is divided into different levels, and a corresponding trigger calibration amount is set for the accumulated mileage of each level.

[0059] The accumulated mileage increases with the use time of the vehicle, and the accumulated fuel consumption and engine running time also increase accordingly. Therefore, different trigger calibration quantities are set according to the accumulated mileage level, and the trigger calibration quantity also increases with the accumulated mileage. For example, the accumulated mileage of 0 to 100 kilometers is level one, the trigger calibration quantity of accumulated fuel consumption is a1, and the trigger calibration quantity of engine running time is b1; the accumulated mileage of 100 to 200 kilometers is level two, the trigger calibration quantity of accumulated fuel consumption is a2 (a2>a1), and the trigger calibration quantity of engine running time is b2 (b2>b1); when the accumulated mileage reaches level two, the accumulated fuel consumption and engine running time are compared with the corresponding trigger calibration quantities a2 and b2 respectively.

[0060] Diagnosing aging by running adaptive characteristic conditions is more accurate than simply judging whether the valve is aged by the accumulated usage time of the valve in the prior art. It is more in line with the actual aging condition of the valve, and the degree of valve aging can be judged to a certain extent by the size of the deviation.

[0061] In this embodiment, the characteristic quantities include charging model characteristic quantities, knock model characteristic quantities and fuel self-learning characteristic quantities.

[0062] This embodiment uses the charging model characteristic quantity, the knock model characteristic quantity and the fuel self-learning characteristic quantity to jointly characterize the valve aging phenomenon, and can accurately diagnose valve aging. All three are indispensable, otherwise it will be impossible to rule out the abnormal operation of the engine caused by other reasons.

[0063] In this embodiment, the inflation model characteristic quantity includes the intake volume difference between the P inflation volume and the throttle valve intake volume; the P inflation volume refers to the intake volume calculated based on the pressure of the intake manifold pressure sensor; the throttle valve intake volume refers to the intake volume calculated based on the throttle valve opening.

[0064] When real aging occurs, the difference in air intake between the P-fill air intake and the throttle air intake will be magnified.

[0065] In this embodiment, the knock model characteristic quantities include an ignition angle correction value, an engine speed acceleration signal, and an engine speed fluctuation signal.

[0066] When real aging occurs and affects engine operation, it will be found that the ignition angle correction value will become larger, the engine acceleration signal jitter will intensify, and the speed fluctuation signal will also be amplified to a certain extent.

[0067] In this embodiment, the fuel self-learning characteristic quantity includes a fuel self-learning correction coefficient.

[0068] When real aging occurs, since the actual EGR exhaust volume is significantly less than the theoretical exhaust volume, the reduction in exhaust volume means that the effective air volume will be significantly larger than the theoretical calculation, and the EMS system injection is calculated based on the effective air intake volume, which will cause the mixture to be significantly rich, causing the fuel self-learning value to significantly deviate from its target value 1 and learn in a smaller direction, such as learning to about 0.8. The verification value of the fuel self-learning correction coefficient will be smaller than the standard value of the fuel self-learning correction coefficient.

[0069] The check values ​​of the above-mentioned characteristic quantities are compared with the standard values ​​of the corresponding characteristic quantities. When they are all above the corresponding deviation threshold, the valve aging is confirmed. It should be noted that the deviation thresholds between the check values ​​of the characteristic quantities and the standard values ​​can be the same or different, depending on the actual vehicle characteristics.

[0070] Example 3

[0071] This embodiment specifically describes how to obtain the standard value of the feature quantity.

[0072] In this embodiment, the standard value of the characteristic quantity is obtained in the following manner: when a new vehicle is started for the first time, it enters an adaptive characteristic operating condition, and the value of the characteristic quantity under the adaptive characteristic operating condition is obtained as the standard value.

[0073] When a new car is started for the first time, it is obvious that the valve has not aged. At this time, the actual flow characteristic curve of the valve is basically consistent with the flow characteristic curve calibrated at the factory. According to the calibrated flow characteristic curve, the adaptive characteristic working condition is entered to obtain the characteristic quantity of the vehicle. Compared with the standard value of the characteristic quantity sampled and calibrated for the vehicle before leaving the factory, it is more accurate.

[0074] In this embodiment, the operating conditions of the adaptive characteristic operating condition include a calibrated engine speed, a calibrated engine torque and a calibrated EGR rate.

[0075] The adaptive characteristic condition operates according to the calibrated engine speed, calibrated engine torque and calibrated EGR rate. Different models of vehicles need to be calibrated for the operating conditions of the adaptive characteristic condition. For economic considerations, sampling calibration is sufficient for the same model of vehicles.

[0076] Example 4

[0077] This embodiment provides a computer-readable storage medium, in which at least one instruction is stored. The instruction is loaded and executed by a processor to implement the method for adaptively correcting valve flow characteristics described in any one of the above embodiments 1 to 3.

[0078] Example 5

[0079] This embodiment provides a controller, including a diagnosis unit and a correction unit;

[0080] The diagnostic unit is used to diagnose whether the valve is aged;

[0081] The correction unit is used to start the cyclic correction mode when the valve aging is confirmed:

[0082] After each correction of the flow characteristic curve is completed, the adaptive characteristic working condition is entered to obtain the verification value of the characteristic quantity, and the deviation between the verification value of the characteristic quantity and the standard value of the characteristic quantity is calculated until the deviation is less than the deviation threshold; the adaptive characteristic working condition refers to the working condition where the operating state is abnormal due to valve aging compared to the condition where the valve is not aged.

[0083] In this embodiment, an autonomous calibration module is also included, which is used to inquire the user whether to enter the adaptive characteristic working condition to calibrate the standard value of the characteristic quantity of the vehicle when the new car is started for the first time. If so, the adaptive characteristic working condition is started and the value of the characteristic quantity under the adaptive characteristic working condition is obtained as the standard value.

[0084] By running the adaptive characteristic working condition to accurately diagnose aging and accurately correct the flow characteristic curve, the correction accuracy of the valve flow characteristic is improved. This embodiment can automatically trigger aging detection and perform flow characteristic correction during the use of the vehicle to maintain a good combustion state of the engine without the need for active maintenance by the user, thereby improving the vehicle experience.

[0085] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A method for adaptively correcting valve flow characteristics, characterized in that: The following steps are involved: When the valve is diagnosed as aging, enter the cycle correction mode: After each correction of the flow characteristic curve is completed, the adaptive characteristic working condition is entered according to the corrected flow characteristic curve to obtain the calibration value of the characteristic quantity, and the deviation between the calibration value of the characteristic quantity and the standard value of the characteristic quantity is calculated until the deviation is less than the deviation threshold; The adaptive characteristic working condition refers to the working condition where the operating state is abnormal due to valve aging compared to the working condition where the valve is not aged.

2. The method for adaptively correcting valve flow characteristics according to claim 1, characterized in that: When the aging detection trigger condition is met, the adaptive characteristic working condition is entered, the verification value of the characteristic quantity under the adaptive characteristic working condition is obtained, and whether aging occurs is determined based on the deviation between the verification value of the characteristic quantity and the standard value of the characteristic quantity.

3. The method for adaptively correcting valve flow characteristics according to claim 2, characterized in that: The aging detection trigger condition is that the accumulated fuel consumption and the engine running time exceed the corresponding trigger calibration amounts respectively.

4. The method for adaptively correcting valve flow characteristics according to claim 3, characterized in that: The accumulated mileage is divided into different levels, and the corresponding trigger calibration amount is set for the accumulated mileage of each level.

5. The method for adaptively correcting valve flow characteristics according to claim 1, characterized in that: The characteristic quantities include charging model characteristic quantities, knock model characteristic quantities and fuel self-learning characteristic quantities.

6. The method for adaptively correcting valve flow characteristics according to claim 5, characterized in that: The charging model characteristic quantity includes the intake volume difference between the P charging volume and the throttle valve intake volume; the P charging volume refers to the intake volume calculated based on the pressure of the intake manifold pressure sensor; the throttle valve intake volume refers to the intake volume calculated based on the throttle valve opening.

7. The method for adaptively correcting valve flow characteristics according to claim 5, characterized in that: The knock model characteristic quantity includes an ignition angle correction value, an engine speed acceleration signal, and an engine speed fluctuation signal.

8. The method for adaptively correcting valve flow characteristics according to claim 5, characterized in that: The fuel self-learning characteristic quantity includes a fuel self-learning correction coefficient.

9. The method for adaptively correcting valve flow characteristics according to claim 1, characterized in that: The standard value of the characteristic quantity is obtained in the following manner: when a new vehicle is started for the first time, it enters an adaptive characteristic working condition, and the value of the characteristic quantity under the adaptive characteristic working condition is obtained as the standard value.

10. The method for adaptively correcting valve flow characteristics according to claim 1, characterized in that: The operating conditions of the adaptive characteristic operating condition include a calibrated engine speed, a calibrated engine torque and a calibrated EGR rate.

11. A computer-readable storage medium, characterized in that: The storage medium stores at least one instruction, which is loaded and executed by the processor to implement the method for adaptively correcting valve flow characteristics as described in any one of claims 1 to 10.

12. A controller, characterized in that: Includes diagnostic unit and correction unit; The diagnostic unit is used to diagnose whether the valve is aged; The correction unit is used to start the cyclic correction mode when the valve aging is confirmed: After each correction of the flow characteristic curve is completed, the adaptive characteristic working condition is entered to obtain the verification value of the characteristic quantity, and the deviation between the verification value of the characteristic quantity and the standard value of the characteristic quantity is calculated until the deviation is less than the deviation threshold; the adaptive characteristic working condition refers to the working condition where the operating state is abnormal due to valve aging compared to the condition where the valve is not aged.

13. The controller according to claim 12, characterized in that: It also includes an autonomous calibration module, which is used to inquire the user whether to enter the adaptive characteristic working condition to calibrate the standard value of the characteristic quantity of the vehicle when the new car is started for the first time. If so, the value of the characteristic quantity under the adaptive characteristic working condition is obtained as the standard value.

Images