A method and system for diagnosing fuel injector faults in a hybrid system engine

Abstract

The present invention belongs to the technical field of diesel engines, and provides a method and system for diagnosing injector faults for hybrid system engines. When the engine reports an injection amount deviation fault, and when the engine torque reaches a preset torque, the first cylinder of the engine is controlled to be cut off to obtain a theoretical torque after the cylinder is cut off; the actual torque of the motor is compared with the theoretical torque to obtain a torque deviation; then, if the torque deviation is less than the preset deviation, the injector fault of the first cylinder is determined; otherwise, the other cylinders of the engine are cut off in sequence until the position of the cylinder corresponding to the injector fault is determined. The motor cooperates with the engine to cut off the cylinder, and then the torque is used to determine whether the injector has a fault and which injector has a fault. The requirements for the degree of fault occurrence are low, and no complex algorithms are required. The cost is low, the feasibility is strong, it is easy to implement, and the judgment is accurate. Compared with the existing technology, it can be faster and can accurately determine which specific injector has a fault.

Description

Technical Field

[0001] The present invention belongs to the technical field of diesel engines, and in particular relates to a method and system for diagnosing injector faults of a hybrid system engine. Background Art

[0002] After long-term use, diesel engine injectors may have carbon deposits on the oil head, causing injector blockage and reduced injection volume. Current technology can use oxygen sensors to calculate the actual injection volume and compare it with the theoretical injection volume to determine whether there is a fuel injection volume deviation fault, but it cannot determine which cylinder injector is faulty. In traditional technology, the speed fluctuation is caused by rail pressure fluctuations after the fuel injector fuel volume deviation, and the fuel volume deviation is determined by monitoring the speed fluctuation. On this basis, improvements are made to determine the speed deviation by the cumulative value of the crankshaft gear disc count; and other methods for injector diagnosis based on algorithms and sample collection.

[0003] However, when diagnosing based on speed fluctuations, firstly, the speed fluctuation cycle is long based on the crankshaft gear counting method, which is difficult to achieve when the working conditions change; secondly, based on the judgment of speed fluctuations, it is easy to judge only when the fault is very serious, otherwise it is difficult to diagnose the fault; other methods based on algorithms to judge injector faults are costly, sample collection is unreliable, and are not suitable for practical applications. In summary, the traditional injector fault diagnosis method cannot quickly and accurately determine which cylinder injector is faulty in a simple way. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a method and system for diagnosing injector faults for a hybrid system engine. The present invention uses a motor to cooperate with the engine to cut off the cylinder, and then uses the torque to determine whether the injector has a fault and which injector has a fault. It has low requirements on the degree of fault occurrence and does not require complex algorithms. It has low cost, strong feasibility, easy implementation, and accurate judgment. Compared with the existing technology, it can be faster and can accurately determine which specific injector has a fault.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, the present invention provides a method for diagnosing a fault of an injector of a hybrid system engine, comprising:

[0007] Obtain the engine torque when the engine reports a fuel injection quantity deviation fault, and the actual torque of the motor;

[0008] When the engine torque reaches a preset torque, the first cylinder of the engine is controlled to be cut off to obtain a theoretical torque after the cylinder is cut off; and the actual torque of the motor is compared with the theoretical torque to obtain a torque deviation;

[0009] If the torque deviation is less than the preset deviation, it is determined that the injector of the first cylinder is faulty; otherwise, the second cylinder of the engine continues to be controlled to be cut off, and the torque deviation after the second cylinder is cut off is continued to be judged. If the torque deviation is less than the preset deviation, it is determined that the injector of the second cylinder is faulty. Otherwise, the other cylinders of the engine are cut off in turn until the position of the cylinder corresponding to the injector failure is determined.

[0010] Furthermore, when determining the first cylinder cut-off object, the cylinder with the highest injector failure frequency in history is cut off; if multiple cylinders have the same injector failure frequency, the cylinder with the longest last maintenance time point is used as the first cylinder cut-off object.

[0011] Furthermore, when determining the cylinder cut-off object after the first cylinder is cut-off, the injector failure frequency, the duration of the last maintenance node, the number of injector atomization failures, the number of sealing failure failures, the number of needle valve jamming failures and the number of internal leakage failures are considered, and the remaining objects after the first cylinder cut-off are sorted, and the cylinders are cut off and diagnosed in sequence according to the sorting order.

[0012] Furthermore, the sorting parameter used for sorting is equal to the weighted sum of the injector fault frequency value, the maintenance node duration value, the number of poor atomization faults, the number of sealing failure faults, the number of needle valve stuck faults and the number of internal leakage faults:

[0013] ;

[0014] in, For the The sorting parameters of each cylinder are sorted in descending order. >2; For the The injector failure frequency value of each cylinder; For the The duration of the maintenance node of each cylinder; For the Number of poor atomization failures in each cylinder; For the Number of seal failures per cylinder; For the The number of needle valve stuck faults in each cylinder; For the Number of internal leakage failures of each cylinder; , , , , and is the weight parameter, the weight corresponding to the injector fault frequency value and the needle valve stuck fault number and , which is greater than the weights corresponding to other factors.

[0015] Furthermore, by judging the deviation between the actual torque of the motor and the set torque of the engine, a correction coefficient of the power-on time is determined; and it is judged again whether the torque deviation meets the requirement.

[0016] Furthermore, after the faulty injector is located, correction is made by controlling the power-on time; after the solenoid valve opening time is increased by a preset value, the torque deviation is judged again. If the torque deviation still does not meet the requirements, the solenoid valve opening time is continued to be increased for correction until the torque deviation meets the requirements; if the torque deviation still does not meet the requirements after the number of corrections is greater than the preset number, the average value of the multiple increases in the solenoid valve opening time is used as the final correction coefficient.

[0017] In a second aspect, the present invention further provides an injector fault diagnosis system for a hybrid system engine, comprising:

[0018] The data acquisition module is configured to: obtain the engine torque when the engine reports a fuel injection amount deviation fault, and the actual torque of the motor;

[0019] The torque deviation calculation module is configured to: when the engine torque reaches a preset torque, control the first cylinder of the engine to be cut off to obtain a theoretical torque after the cylinder is cut off; compare the actual torque of the motor with the theoretical torque to obtain a torque deviation;

[0020] The fault diagnosis module is configured as follows: if the torque deviation is less than a preset deviation, it is determined that the injector of the first cylinder is faulty; otherwise, the second cylinder of the engine continues to be controlled to be cut off, and the torque deviation after the second cylinder is cut off is continued to be determined. If the torque deviation is less than the preset deviation, it is determined that the injector of the second cylinder is faulty; otherwise, the other cylinders of the engine are cut off in turn until the position of the cylinder corresponding to the injector fault is determined.

[0021] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the injector fault diagnosis method for a hybrid system engine described in the first aspect.

[0022] In a fourth aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein when the processor executes the computer program, the steps of the injector fault diagnosis method for a hybrid system engine described in the first aspect are implemented.

[0023] In a fifth aspect, the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the steps of the injector fault diagnosis method for a hybrid system engine described in the first aspect are implemented.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. In the present invention, when the engine reports a fuel injection amount deviation fault and the engine torque reaches a preset torque, the first cylinder of the engine is controlled to be cut off to obtain the theoretical torque after the cylinder is cut off; the actual torque of the motor is compared with the theoretical torque to obtain the torque deviation; then, if the torque deviation is less than the preset deviation, the fuel injector of the first cylinder is determined to be faulty; otherwise, the second cylinder of the engine is controlled to be cut off to judge the torque deviation after the second cylinder is cut off. If the torque deviation is less than the preset deviation, the fuel injector of the second cylinder is judged to be faulty, otherwise, the other cylinders of the engine are cut off in sequence until the position of the cylinder corresponding to the fuel injector fault is determined. The motor cooperates with the engine to cut off the cylinder, and then the torque is used to judge whether the fuel injector has a fault and which fuel injector has a fault. The degree of fault occurrence is low, and no complex algorithm is required. The cost is low, the feasibility is strong, it is easy to implement, and the judgment is accurate. Compared with the existing technology, it can be faster and can accurately judge which specific fuel injector has a fault.

[0026] 2. The present invention utilizes the characteristics of the hybrid system, cooperates with the engine to cut off the cylinder through the motor, and then determines whether the injector fails and which injector fails through the torque. It can quickly and accurately determine which specific injector has failed, and provides a method for correcting the oil volume to meet the engine torque requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0028] Figure 1 This is a fault location diagnosis flow chart of Example 1 of the present invention;

[0029] Figure 2 This is the oil quantity correction flow chart of Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0032] Hybrid system: refers to a powertrain that uses both fuel-driven and electric-driven modes.

[0033] Cylinder cut-off: A method of controlling the injector of a cylinder of a multi-cylinder engine through software to stop injecting fuel.

[0034] Power-on time: The engine injector controls fuel injection through a solenoid valve. The opening time of the solenoid valve is used to control different injection amounts. The opening time of the solenoid valve is the power-on time.

[0035] The actual torque of the motor refers to the output torque of the motor under actual working conditions.

[0036] This patent applies to the direct judgment of injector faults by this method. This patent also applies to the correction of injector faults by modifying the injection amount, increasing the motor torque, etc.

[0037] Embodiment 1:

[0038] This embodiment provides a method for diagnosing injector faults for a hybrid system engine. When the engine reports an injector oil quantity deviation, it is diagnosed that the specific cylinder injector has a deviation, and the injector injection quantity is corrected by correcting the injector power-on time. Specifically, the hybrid system can use the motor to drag the engine to a preset point and cut off the cylinder, and determine which cylinder injector has a problem through the uneven torque of each cylinder; and the hybrid can measure the torque of the whole vehicle, and the injection quantity can be corrected according to the measured torque; the method includes:

[0039] S1. When the engine reports a fuel injection quantity deviation fault, perform injector fault location diagnosis:

[0040] The motor controls the engine to the preset diagnostic point speed, and the engine controls the preset diagnostic point torque, and cuts off the cylinders in sequence. By comparing the actual torque of the motor with the theoretical torque after the engine cuts off the cylinder, the torque deviation is obtained. If the torque deviation is greater than the preset deviation threshold, it is considered that there is a damaged injector in the injectors that have not cut off the cylinder; if the torque deviation is less than the preset deviation threshold, it is considered that the injectors that have not cut off the cylinder are normal, and the injectors that have cut off the cylinder are damaged injectors. Specifically, the engine torque and the actual torque of the motor are obtained when the engine reports the fuel injection amount deviation fault; when the engine torque reaches the preset torque, the first cylinder of the engine is controlled to cut off the cylinder to obtain the theoretical torque after the cylinder is cut off; the actual torque of the motor is compared with the theoretical torque to obtain the torque deviation; if the torque deviation is less than the preset deviation, it is determined that the injector of the first cylinder is faulty; otherwise, the second cylinder of the engine is continued to be controlled to cut off the cylinder, and the torque deviation after the second cylinder is cut off is continued to be judged. If the torque deviation is less than the preset deviation, it is determined that the injector of the second cylinder is faulty, otherwise, the other cylinders of the engine are cut off in sequence until the position of the cylinder corresponding to the injector fault is determined.

[0041] In this embodiment, multiple cylinders in the engine can be numbered, and the cylinders can be cut off in sequence according to the numbers. In other embodiments, in order to increase the speed of determining the specific location of the injector fault, when determining the first cylinder cut-off object and determining the subsequent cylinder cut-off objects in sequence, the injector historical fault data is considered to minimize the number of cylinder cut-offs; specifically, optional:

[0042] When determining the first cylinder cut-off object, the cylinder with the highest injector failure frequency in history will be cut off; if multiple cylinders have the same injector failure frequency, the cylinder with the longest last maintenance time point will be used as the first cylinder cut-off object; in this way, by giving priority to the object with the highest failure frequency and the one that has not been repaired for a long time, the diagnosis probability after the first cylinder cut-off is increased, and the efficiency of determining the injector failure location is improved.

[0043] When determining the subsequent cylinder disconnection objects, the injector failure frequency, the duration of the last maintenance node, the number of poor injector atomization failures, the number of seal failure failures, the number of needle valve stuck failures, and the number of internal leakage failures are considered, and the remaining objects after the first cylinder disconnection are sorted, and the cylinders are disconnected and diagnosed in sequence according to the sorting order. Specifically, the sorting parameter used for sorting is equal to the weighted sum of the injector failure frequency value, the maintenance node duration value, the number of poor atomization failures, the number of seal failure failures, the number of needle valve stuck failures, and the number of internal leakage failures:

[0044]

[0045] in, For the The sorting parameters of each cylinder are sorted in descending order. >2; For the The injector failure frequency value of each cylinder; For the The duration of the maintenance node of each cylinder; For the Number of poor atomization failures in each cylinder; For the Number of seal failures per cylinder; For the The number of needle valve stuck faults in each cylinder; For the Number of internal leakage failures of each cylinder; , , , , and is the weight parameter, optional. =0.3, =0.1, =0.1, =0.1, =0.3, =0.1.

[0046] In this embodiment, when determining the subsequent cylinder disconnection object, the injector fault frequency, the duration of the last maintenance node, the number of times the injector atomization failure occurs, the number of times the sealing failure occurs, the number of times the needle valve is stuck, and the number of times the internal leakage occurs are considered, and the remaining objects after the first cylinder disconnection are sorted, and the cylinders are disconnected and diagnosed in sequence according to the sorting order. Considering multiple factors to determine the subsequent cylinder disconnection sequence can improve the diagnosis probability after each subsequent cylinder disconnection, and further improve the efficiency of determining the injector fault location. Among them, carbon deposition is the main cause of the needle valve stuck fault. The weights corresponding to the injector fault frequency value and the needle valve stuck fault number are greater than the weights corresponding to other factors, and the fuel injection oil quantity deviation fault can be quickly determined.

[0047] S2. After locating the faulty injector, make oil quantity correction:

[0048] like Figure 2 As shown, the motor controls the corrected speed, the engine controls the corrected torque a, and the power-on time correction coefficient is determined by judging the deviation between the actual motor torque and the set engine torque; and again judging whether the torque deviation meets the requirement; if it meets the requirement, the engine controls the verified torque b, and again judges the correction result, and if it does not meet the requirement, corrects it again. When multiple corrections cannot meet a and b at the same time, the corrected average of the two is taken.

[0049] Specifically, after the faulty fuel injector is located, the power-on time is controlled to make corrections, and the opening time of the control solenoid valve is increased to increase the fuel injection amount, thereby compensating for the reduced fuel injection amount after the fuel injector is blocked due to the carbon deposition in the fuel head. After the opening time of the solenoid valve is increased by a preset value, the torque deviation is judged again. If the torque deviation still does not meet the requirements, the opening time of the solenoid valve is continued to be increased for correction until the torque deviation meets the requirements; if the torque deviation still does not meet the requirements after the number of corrections exceeds the preset number, the average value of the multiple increases in the opening time of the solenoid valve is used as the final correction coefficient.

[0050] This embodiment utilizes the characteristics of the hybrid system, cooperates with the engine to cut off the cylinder through the motor, and then determines whether the injector has failed and which injector has failed through the torque. It is highly feasible, easy to implement, and accurate in judgment. Compared with the existing technology, it can more quickly and accurately determine which specific injector has failed, and provides a method for correcting the oil amount, which is impossible with the existing methods.

[0051] Embodiment 2:

[0052] This embodiment provides an injector fault diagnosis system for a hybrid system engine, comprising:

[0053] The data acquisition module is configured to: obtain the engine torque when the engine reports a fuel injection amount deviation fault, and the actual torque of the motor;

[0054] The torque deviation calculation module is configured to: when the engine torque reaches a preset torque, control the first cylinder of the engine to be cut off to obtain a theoretical torque after the cylinder is cut off; compare the actual torque of the motor with the theoretical torque to obtain a torque deviation;

[0055] The fault diagnosis module is configured as follows: if the torque deviation is less than a preset deviation, it is determined that the injector of the first cylinder is faulty; otherwise, the second cylinder of the engine continues to be controlled to be cut off, and the torque deviation after the second cylinder is cut off is continued to be determined. If the torque deviation is less than the preset deviation, it is determined that the injector of the second cylinder is faulty; otherwise, the other cylinders of the engine are cut off in turn until the position of the cylinder corresponding to the injector fault is determined.

[0056] The working method of the system is the same as the injector fault diagnosis method for a hybrid system engine in Example 1, and will not be described in detail here.

[0057] Embodiment 3:

[0058] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the injector fault diagnosis method for a hybrid system engine described in Example 1 are implemented.

[0059] Embodiment 4:

[0060] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, the steps of the injector fault diagnosis method for a hybrid system engine described in Example 1 are implemented.

[0061] Embodiment 5:

[0062] This embodiment provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the steps of the injector fault diagnosis method for a hybrid system engine described in Example 1 are implemented.

[0063] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A method for diagnosing injector faults in a hybrid system engine, characterized in that: include: Obtain the engine torque when the engine reports a fuel injection quantity deviation fault, and the actual torque of the motor; When the engine torque reaches a preset torque, the first cylinder of the engine is controlled to be cut off, so as to obtain a theoretical torque after the cylinder is cut off; Comparing the actual torque of the motor with the theoretical torque to obtain a torque deviation; If the torque deviation is less than the preset deviation, it is determined that the fuel injector of the first cylinder is faulty; otherwise, the second cylinder of the engine is continuously controlled to be cut off, and the torque deviation after the second cylinder is cut off is continuously determined. If the torque deviation is less than the preset deviation, it is determined that the fuel injector of the second cylinder is faulty; otherwise, the other cylinders of the engine are cut off in sequence until the position of the cylinder corresponding to the fuel injector fault is determined; When determining the cylinder cut-off objects after the first cylinder cut-off, the injector failure frequency, the duration of the last maintenance node, the number of injector atomization failures, the number of seal failure failures, the number of needle valve stuck failures and the number of internal leakage failures are considered, and the remaining objects after the first cylinder cut-off are sorted, and the cylinders are cut off and diagnosed in sequence according to the sorting order; The sorting parameter used for sorting is equal to the weighted sum of the injector fault frequency value, the maintenance node duration value, the number of poor atomization faults, the number of seal failure faults, the number of needle valve stuck faults and the number of internal leakage faults: ； in, For the The sorting parameters of each cylinder are sorted in descending order. >2; For the The injector failure frequency value of each cylinder; For the The duration of the maintenance node of each cylinder; For the Number of poor atomization failures in each cylinder; For the Number of seal failures per cylinder; For the The number of needle valve stuck faults in each cylinder; For the Number of internal leakage failures of each cylinder; , , , , and is the weight parameter, the weight corresponding to the injector fault frequency value and the needle valve stuck fault number and , which is greater than the weights corresponding to other factors; By judging the deviation between the actual torque of the motor and the set torque of the engine, the correction coefficient of the power-on time is determined; and it is judged again whether the torque deviation meets the requirements.

2. A method for diagnosing a fuel injector fault in a hybrid system engine according to claim 1, characterized in that: When determining the first cylinder cut-off object, the cylinder with the highest injector failure frequency in history will be cut off; if multiple cylinders have the same injector failure frequency, the cylinder with the longest last maintenance time point will be the first cylinder cut-off object.

3. The method for diagnosing a fuel injector fault for a hybrid system engine according to claim 1, characterized in that: After the faulty injector is located, it is corrected by controlling the power-on time; after the solenoid valve opening time increases by a preset value, the torque deviation is judged again. If the torque deviation still does not meet the requirements, the solenoid valve opening time is continued to be increased for correction until the torque deviation meets the requirements; if the torque deviation still does not meet the requirements after the number of corrections is greater than the preset number, the average value of the multiple increases in the solenoid valve opening time is used as the final correction coefficient.

4. A fuel injector fault diagnosis system for a hybrid system engine, characterized in that: include: The data acquisition module is configured to: obtain the engine torque when the engine reports a fuel injection amount deviation fault, and the actual torque of the motor; The torque deviation calculation module is configured to: when the engine torque reaches a preset torque, control the first cylinder of the engine to be cut off to obtain a theoretical torque after the cylinder is cut off; compare the actual torque of the motor with the theoretical torque to obtain a torque deviation; The fault diagnosis module is configured to: if the torque deviation is less than a preset deviation, determine that the fuel injector of the first cylinder is faulty; otherwise, continue to control the second cylinder of the engine to be cut off, and continue to determine the torque deviation after the second cylinder is cut off, and if the torque deviation is less than the preset deviation, determine that the fuel injector of the second cylinder is faulty; otherwise, cut off the other cylinders of the engine in sequence until the position of the cylinder corresponding to the fuel injector fault is determined; When determining the cylinder cut-off objects after the first cylinder cut-off, the injector failure frequency, the duration of the last maintenance node, the number of injector atomization failures, the number of seal failure failures, the number of needle valve stuck failures and the number of internal leakage failures are considered, and the remaining objects after the first cylinder cut-off are sorted, and the cylinders are cut off and diagnosed in sequence according to the sorting order; The sorting parameter used for sorting is equal to the weighted sum of the injector fault frequency value, the maintenance node duration value, the number of poor atomization faults, the number of seal failure faults, the number of needle valve stuck faults and the number of internal leakage faults: ； in, For the The sorting parameters of each cylinder are sorted in descending order. >2; For the The injector failure frequency value of each cylinder; For the The duration of the maintenance node of each cylinder; For the Number of poor atomization failures in each cylinder; For the Number of seal failures per cylinder; For the The number of needle valve stuck faults in each cylinder; For the Number of internal leakage failures of each cylinder; , , , , and is the weight parameter, the weight corresponding to the injector fault frequency value and the needle valve stuck fault number and , which is greater than the weights corresponding to other factors; By judging the deviation between the actual torque of the motor and the set torque of the engine, the correction coefficient of the power-on time is determined; and it is judged again whether the torque deviation meets the requirements.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the injector fault diagnosis method for a hybrid system engine as described in any one of claims 1 to 3 are implemented.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the computer program, the steps of the injector fault diagnosis method for a hybrid system engine are implemented as described in any one of claims 1 to 3.

7. A computer program product, characterized in that The computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the injector fault diagnosis method for a hybrid system engine as claimed in any one of claims 1 to 3 are implemented.

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