An engine injector fault diagnosis method, storage medium, and device

Abstract

The present invention discloses a method, a storage medium, and a device for diagnosing faults of an engine injector, which relate to the field of engines and related systems. The method includes determining whether to enter the injector fault diagnosis mode based on the injector diagnosis requirements and in combination with the current state of the vehicle; when entering the injector fault diagnosis mode, selecting the engine speed change diagnosis method or the cyclic fuel supply change diagnosis method to implement injector fault diagnosis; wherein, the engine speed change diagnosis method is based on the absolute difference in the engine speed before and after injector fault diagnosis, and the cyclic fuel supply change diagnosis method is based on the absolute difference in the engine cyclic fuel supply before and after injector fault diagnosis. The present invention can effectively improve the safety, simplicity, and accuracy of injector fault diagnosis, and reduce the diagnosis cost.

Description

Technical Field

[0001] The present invention relates to the field of engines and related systems, and particularly to a method, a storage medium, and a device for diagnosing faults of an engine injector. Background Art

[0002] Currently, electronically controlled injectors are mainly used in engines to supply fuel to the engine. When injector faults occur, it will cause phenomena such as insufficient engine power and excessive vibration. Since the injectors are mainly installed on structures such as the engine cylinder head, in order to determine whether an injector has a fault, a common approach is as follows: After starting the engine, the repair technician uses experience and human hearing sense at the cylinder barrel of the cylinder block to judge whether the corresponding combustion chamber is burning normally based on the combustion noise of the engine, and then replaces the injector for testing to check whether the engine fault phenomenon disappears, thereby determining whether the injector has a fault; or preliminarily judge the injector fault based on the engine fault phenomenon, and then remove all injectors and send them to a professional testing institution for testing.

[0003] For the existing methods of judging whether an injector is faulty, the repair technician uses experience and human hearing sense at the cylinder barrel of the cylinder block to judge whether the corresponding combustion chamber is burning normally through the combustion noise of the engine, which has serious safety hazards, and the diagnostic accuracy of human experience sense is not high, which is very likely to cause misdiagnosis; if all the engine injectors are directly removed and sent to a professional testing institution for testing, it will lead to high testing costs (the labor cost of disassembling and assembling the injector, the testing cost of the professional testing institution, and the time cost), and it is very likely to have misdetection (the fault phenomenon that appears in the engine is similar to that caused by the injector fault, but it is not caused by the injector fault, and the injector is removed and sent to the testing institution for testing), which is not applicable to the repair and fault repair in the market. Summary of the Invention

[0004] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a method, a storage medium, and a device for diagnosing faults of an engine injector, which can effectively improve the safety, simplicity, and accuracy of injector fault diagnosis, and reduce the diagnosis cost.

[0005] To achieve the above purpose, a method for diagnosing faults of an engine injector provided by the present invention specifically includes the following steps:

[0006] Based on the injector diagnosis requirements and combined with the current state of the vehicle, determine whether to enter the injector fault diagnosis mode;

[0007] When entering the injector fault diagnosis mode, select the rotational speed change diagnosis method or the cyclic fuel supply change diagnosis method to implement injector fault diagnosis;

[0008] Among them, the rotational speed change diagnosis method is based on the absolute difference in the engine rotational speed before and after the fuel injector fault diagnosis, and the cyclic fuel supply change diagnosis method is based on the absolute difference in the engine cyclic fuel supply before and after the fuel injector fault diagnosis.

[0009] Based on the above technical solution, according to the fuel injector diagnosis requirements and in combination with the current vehicle state to determine whether to enter the fuel injector fault diagnosis mode, the specific steps include:

[0010] Create an engine diagnostic device for connecting to the engine's ECU, and send a fuel injector diagnosis requirement signal to the ECU through the engine diagnostic device;

[0011] The ECU receives the fuel injector diagnosis requirement signal, obtains the current vehicle state, and determines whether to enter the fuel injector fault diagnosis mode according to the obtained current vehicle state.

[0012] Based on the above technical solution, the current vehicle state includes the vehicle speed information, clutch state, brake state, and engine state.

[0013] Based on the above technical solution,

[0014] When the vehicle speed is less than the set safety value, the clutch state is disengaged, the brake state is activated, and the engine is in the running state, then enter the fuel injector fault diagnosis mode; otherwise, do not enter or exit the fuel injector fault diagnosis mode.

[0015] Based on the above technical solution, for the rotational speed change diagnosis method, the specific diagnosis steps include:

[0016] Send the engine cyclic fuel supply requirement to the ECU through the engine diagnostic device;

[0017] Based on the cyclic fuel injection quantity in the engine cyclic fuel supply requirement, the fuel injectors of each cylinder of the engine inject fuel, and obtain the engine rotational speed as the engine rotational speed before the fuel injector fault diagnosis;

[0018] The engine diagnostic device sends the cylinder number of the current fuel injector to be diagnosed to the ECU, and the ECU controls the current fuel injector to stop injecting fuel, and obtains the engine rotational speed at this time as the engine rotational speed after the fuel injector fault diagnosis;

[0019] Judge whether the absolute difference between the engine rotational speed after the fuel injector fault diagnosis and the engine rotational speed before the fuel injector fault diagnosis is less than the set allowable fluctuation value of the engine rotational speed:

[0020] If so, it indicates that the current fuel injector has a fault;

[0021] If not, it indicates that the current fuel injector is operating normally.

[0022] On the basis of the above technical solution, the allowable fluctuation value of the engine speed is set according to the vehicle model, and for engines with the same model, the set allowable fluctuation value of the engine speed is the same.

[0023] On the basis of the above technical solution, for the cyclic fuel supply variation diagnosis method, the specific diagnosis steps include:

[0024] Send the engine target speed demand to the ECU through the engine diagnostic device, and the engine operates at the target speed in the engine target speed demand.

[0025] Self-regulate the cyclic fuel supply demand through PID, and use the engine cyclic fuel supply at this time as the engine cyclic fuel supply before injector fault diagnosis.

[0026] The engine diagnostic device sends the cylinder number of the current injector to be diagnosed to the ECU, and the ECU controls the current injector to stop fuel injection, and obtains the engine cyclic fuel supply at this time as the engine cyclic fuel supply after injector fault diagnosis.

[0027] Judge whether the absolute difference between the engine cyclic fuel supply before injector fault diagnosis and the engine cyclic fuel supply after injector fault diagnosis is less than the set allowable fluctuation value of the engine cyclic fuel supply:

[0028] If so, it indicates that the current injector has a fault.

[0029] If not, it indicates that the current injector is operating normally.

[0030] On the basis of the above technical solution, the allowable fluctuation value of the engine cyclic fuel supply is set according to the vehicle model, and for engines with the same model, the set allowable fluctuation value of the engine cyclic fuel supply is the same.

[0031] A readable storage medium provided by the present invention is located in the PLC controller. A computer program is stored on the readable storage medium, and when the program is executed by a processor, the above-mentioned engine injector fault diagnosis method is implemented.

[0032] An engine injector engine diagnostic device provided by the present invention includes:

[0033] A determination module, which is used to determine whether to enter the injector fault diagnosis mode based on the injector diagnosis demand and in combination with the current state of the vehicle.

[0034] A diagnosis module, which is used to select the speed change diagnosis method or the cyclic fuel supply change diagnosis method to implement injector fault diagnosis when entering the injector fault diagnosis mode.

[0035] Among them, the rotational speed change diagnosis method is based on the absolute difference in the engine rotational speed before and after the fuel injector fault diagnosis, and the cyclic fuel supply change diagnosis method is based on the absolute difference in the engine cyclic fuel supply before and after the fuel injector fault diagnosis.

[0036] Compared with the prior art, the advantages of the present invention are as follows: By connecting the engine diagnosis device to the engine control unit ECU and sending out a diagnosis requirement, the engine ECU determines whether to enter the fuel injector fault diagnosis mode according to the signals related to the engine operating state and the diagnosis requirement. When entering the fuel injector fault diagnosis mode, the rotational speed change diagnosis method or the cyclic fuel supply change diagnosis method is selected to implement the fuel injector fault diagnosis: When using the rotational speed change diagnosis method, the fuel injection requirement of the fuel injector to be diagnosed is input to the ECU through the engine diagnosis device, and the engine ECU sends the engine rotational speed signals before and after the diagnosis to the engine diagnosis device. The engine diagnosis device determines whether the fuel injector fails by comparing the deviation of the engine rotational speed before and after the diagnosis; When using the cyclic fuel supply change diagnosis method, the engine rotational speed requirement to be diagnosed is input to the ECU through the engine diagnosis device, and the engine ECU sends the magnitudes of the engine cyclic fuel supply before and after the diagnosis to the engine diagnosis device. The engine diagnosis device determines whether the fuel injector fails by comparing the deviation magnitudes of the engine cyclic fuel supply before and after the diagnosis. The present invention can effectively improve the safety, simplicity, and accuracy of the fuel injector fault diagnosis and reduce the diagnosis cost. Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a flowchart of a method for diagnosing engine fuel injector faults in an embodiment of the present invention;

[0039] Figure 2 It is a logical implementation diagram of a method for diagnosing engine fuel injector faults in an embodiment of the present invention;

[0040] Figure 3 It is a logic diagram of the rotational speed change diagnosis method;

[0041] Figure 4 It is a logic diagram of the cyclic fuel supply change diagnosis method. Detailed Embodiments

[0042] A method for diagnosing faults of an engine injector provided by an embodiment of the present invention connects an engine diagnostic device to an engine control unit (ECU) to issue a diagnostic requirement. The engine ECU determines whether to enter the injector fault diagnosis mode based on signals related to the engine operating state and the diagnostic requirement. When entering the injector fault diagnosis mode, the rotational speed change diagnosis method or the cyclic fuel supply change diagnosis method is selected to implement injector fault diagnosis: when using the rotational speed change diagnosis method, the engine diagnostic device inputs the fuel injection requirement of the injector to be diagnosed to the ECU, and the ECU sends the engine rotational speed signals before and after diagnosis to the engine diagnostic device. The engine diagnostic device determines whether the injector is faulty by comparing the deviation of the engine rotational speed before and after diagnosis; when using the cyclic fuel supply change diagnosis method, the engine diagnostic device inputs the engine rotational speed requirement to be diagnosed to the ECU, and the ECU sends the magnitudes of the engine cyclic fuel supply before and after diagnosis to the engine diagnostic device. The engine diagnostic device determines whether the injector is faulty by comparing the deviation magnitudes of the engine cyclic fuel supply before and after diagnosis. The present invention can effectively improve the safety, simplicity, and accuracy of injector fault diagnosis and reduce the diagnostic cost. An embodiment of the present invention also correspondingly provides an engine injector engine diagnostic device.

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application.

[0044] See Figure 1 As shown, a method for diagnosing faults of an engine injector provided by an embodiment of the present invention specifically includes the following steps:

[0045] S1: Based on the injector diagnostic requirement and combined with the current state of the vehicle, determine whether to enter the injector fault diagnosis mode;

[0046] S2: When entering the injector fault diagnosis mode, select the rotational speed change diagnosis method or the cyclic fuel supply change diagnosis method to implement injector fault diagnosis;

[0047] Among them, the rotational speed change diagnosis method is based on the absolute difference in the engine rotational speed before and after injector fault diagnosis, and the cyclic fuel supply change diagnosis method is based on the absolute difference in the engine cyclic fuel supply before and after injector fault diagnosis.

[0048] In the present invention, based on the injector diagnostic requirement and combined with the current state of the vehicle, to determine whether to enter the injector fault diagnosis mode, the specific steps include:

[0049] S101: Create an engine diagnostic device for connecting to the engine's ECU, and send an injector diagnostic requirement signal to the ECU through the engine diagnostic device. It should be noted that the engine diagnostic device in the present invention is a hardware device capable of signal transmission and data calculation and comparison, such as sending injector diagnostic requirement signals, engine cycle fuel supply requirements, engine target speed requirements, and cylinder number information.

[0050] S102: The ECU receives the injector diagnostic requirement signal, obtains the current vehicle state, and determines whether to enter the injector fault diagnosis mode based on the obtained current vehicle state.

[0051] In the present invention, the current vehicle state includes the vehicle speed information, clutch state, brake state, and engine state. When the vehicle speed is less than the set safety value (defined according to vehicle model requirements), the clutch state is disengaged, the brake state is activated, and the engine is in the running state, then enter the injector fault diagnosis mode; otherwise, do not enter or exit the injector fault diagnosis mode.

[0052] That is, as Figure 2 shown, when the vehicle speed is less than the set safety value, the clutch state is disengaged, the brake state is activated, and the engine is in the running state, then enter the injector fault diagnosis mode after receiving the injector diagnostic requirement signal; when any of the above conditions is not met, do not enter or exit the injector fault diagnosis mode. When entering the injector fault diagnosis mode, select a diagnostic method for diagnostic calculation.

[0053] In the present invention, for the rotational speed change diagnosis method, see Figure 3 shown, the specific diagnostic steps include:

[0054] S201: Send the engine cycle fuel supply requirement to the ECU through the engine diagnostic device;

[0055] S202: Based on the fuel injection amount per cycle in the engine cycle fuel supply requirement, the fuel injectors of each cylinder of the engine inject fuel, and obtain the engine speed, which is used as the engine speed Speed before injector fault diagnosis;

[0056] That is, when the engine enters the rotational speed change diagnosis method, send the engine cycle fuel supply requirement to the ECU through the engine diagnostic device, and the fuel injectors of each cylinder of the engine inject fuel according to the fuel injection amount per cycle requirement, and then record and save the engine speed at this time.

[0057] S203: The engine diagnostic device sends the cylinder number N of the current injector to be diagnosed to the ECU, the ECU controls the current injector to stop fuel injection, and obtains the engine speed at this time, which is used as the engine speed Speed_N after injector fault diagnosis;

[0058] S204: Determine whether the absolute difference Speed_D between the engine speed after diagnosing the fuel injector fault and the engine speed before diagnosing the fuel injector fault is less than the set allowable engine speed fluctuation value Speed_limit:

[0059] If so, it indicates that whether the current fuel injector is misfiring has no impact on the operation of the engine, indicating that the current fuel injector has a fault;

[0060] If not, it indicates that the current fuel injector is operating normally.

[0061] Among them, for Speed_D, its calculation method is Speed_D = |Speed - Speed_N|.

[0062] It should be noted that when using the engine speed change diagnosis method to diagnose whether the fuel injector is faulty, each fuel injector on the engine is diagnosed in turn. For example, based on the fuel injection volume in the engine cycle fuel supply demand, each cylinder fuel injector of the engine injects fuel, and the engine speed is obtained as the engine speed before diagnosing the fuel injector fault. The engine diagnosis device first sends the cylinder number 1 corresponding to the fuel injector of cylinder 1 to be diagnosed to the ECU, and the ECU controls the fuel injector on cylinder 1 to stop injecting fuel, and obtains the engine speed at this time as the engine speed after diagnosing the fuel injector fault. Then, when the absolute difference is less than the allowable engine speed fluctuation value, it indicates that the fuel injector on cylinder 1 has a fault, otherwise, the fuel injector on cylinder 1 is operating normally; then, again based on the fuel injection volume in the engine cycle fuel supply demand, each cylinder fuel injector of the engine injects fuel, and the engine speed is obtained as the engine speed before diagnosing the fuel injector fault. The engine diagnosis device sends the cylinder number 2 corresponding to the fuel injector of cylinder 2 to be diagnosed to the ECU, and the ECU controls the fuel injector on cylinder 2 to stop injecting fuel, and obtains the engine speed at this time as the engine speed after diagnosing the fuel injector fault, and calculates the absolute difference again. Then, when the absolute difference is less than the allowable engine speed fluctuation value, it indicates that the fuel injector on cylinder 2 has a fault, otherwise, the fuel injector on cylinder 2 is operating normally, and so on.

[0063] In the present invention, the allowable engine speed fluctuation value is set according to the vehicle model, and for engines of the same model, the set allowable engine speed fluctuation value is the same.

[0064] In the present invention, for the fuel supply volume change diagnosis method, see Figure 4 As shown, the specific diagnosis steps include:

[0065] S211: Send the engine target speed demand to the ECU through the engine diagnosis device, and the engine operates according to the target speed in the engine target speed demand;

[0066] S212: Adjust the fuel supply demand of the cycle through PID self-regulation, and use the engine cycle fuel supply at this time as the engine cycle fuel supply Qfuel before the fuel injector fault diagnosis;

[0067] S213: The engine diagnostic device sends the cylinder number of the current fuel injector to be diagnosed to the ECU. The ECU controls the current fuel injector to stop fuel injection, and obtains the engine cycle fuel supply at this time as the engine cycle fuel supply Qfuel_N after the fuel injector fault diagnosis;

[0068] S214: Determine whether the absolute difference Qfuel_D between the engine cycle fuel supply before the fuel injector fault diagnosis and the engine cycle fuel supply after the fuel injector fault diagnosis is less than the set allowable fluctuation value Qfuel_limit of the engine cycle fuel supply:

[0069] If so, it indicates that whether the current fuel injector has a cylinder cut-off has no impact on the current engine operation, indicating that the current fuel injector has a fault;

[0070] If not, it indicates that the current fuel injector is operating normally.

[0071] Among them, for Qfuel_D, the calculation method is Qfuel_D = |Qfuel - Qfuel_N|.

[0072] It should be noted that when using the cycle fuel supply change diagnosis method for fuel injector fault diagnosis, each fuel injector on the engine is diagnosed in turn. For example, the engine operates at the target speed in the engine target speed demand, and the engine cycle fuel supply at this time is obtained as the engine cycle fuel supply before the fuel injector fault diagnosis. The engine diagnostic device first sends the cylinder number 1 corresponding to the fuel injector of cylinder 1 to be diagnosed to the ECU. The ECU controls the fuel injector on cylinder 1 to stop fuel injection, and obtains the engine cycle fuel supply at this time as the engine cycle fuel supply after the fuel injector fault diagnosis, and judges whether the fuel injector on cylinder 1 has a fault based on the calculated absolute difference; then the engine operates again at the target speed in the engine target speed demand, and the engine cycle fuel supply at this time is obtained as the engine cycle fuel supply before the fuel injector fault diagnosis. The engine diagnostic device sends the cylinder number 2 corresponding to the fuel injector of cylinder 2 to be diagnosed to the ECU. The ECU controls the fuel injector on cylinder 2 to stop fuel injection, and obtains the engine cycle fuel supply at this time as the engine cycle fuel supply after the fuel injector fault diagnosis, and judges whether the fuel injector on cylinder 2 has a fault based on the calculated absolute difference, and so on.

[0073] In the present invention, the allowable fluctuation value of the engine cycle fuel supply is set according to the vehicle model, and for engines of the same model, the set allowable fluctuation value of the engine cycle fuel supply is the same.

[0074] According to the diagnostic requirements sent by the engine diagnostic device, the ECU combines relevant signals to determine whether to enter the fuel injector fault diagnosis mode while ensuring the safe operation of the engine; the fuel injector to be diagnosed is sent by the engine diagnostic device, and its fuel injection state is controlled; the engine operating speed or the cyclic fuel supply amount before and after the fuel injector fault diagnosis is judged to determine whether the fuel injector fails.

[0075] The engine fuel injector fault diagnosis method according to the embodiment of the present invention connects the engine diagnostic device to the engine control unit ECU to issue diagnostic requirements. The engine ECU determines whether to enter the fuel injector fault diagnosis mode according to the relevant signals of the engine operating state and the diagnostic requirements. When entering the fuel injector fault diagnosis mode, the rotational speed change diagnosis method or the cyclic fuel supply amount change diagnosis method is selected to implement the fuel injector fault diagnosis: when the rotational speed change diagnosis method is used, the fuel injection requirement of the fuel injector to be diagnosed is input to the ECU through the engine diagnostic device, and the engine ECU sends the engine speed signals before and after the diagnosis to the engine diagnostic device. The engine diagnostic device determines whether the fuel injector fails by comparing the rotational speed deviation of the engine before and after the diagnosis; when the cyclic fuel supply amount change diagnosis method is used, the engine speed requirement to be diagnosed is input to the ECU through the engine diagnostic device, and the engine ECU sends the magnitudes of the engine cyclic fuel supply amounts before and after the diagnosis to the engine diagnostic device. The engine diagnostic device determines whether the fuel injector fails by comparing the deviation magnitudes of the engine cyclic fuel supply amounts before and after the diagnosis. The present invention can effectively improve the safety, simplicity, and accuracy of the fuel injector fault diagnosis, and reduce the diagnostic cost.

[0076] In a possible implementation manner, the embodiment of the present invention further provides a readable storage medium. The readable storage medium is located in a PLC (Programmable Logic Controller) controller, and a computer program is stored on the readable storage medium. When the program is executed by a processor, the steps of the following engine fuel injector fault diagnosis method are implemented:

[0077] Based on the fuel injector diagnostic requirements and combined with the current state of the vehicle, it is determined whether to enter the fuel injector fault diagnosis mode;

[0078] When entering the fuel injector fault diagnosis mode, the rotational speed change diagnosis method or the cyclic fuel supply amount change diagnosis method is selected to implement the fuel injector fault diagnosis;

[0079] Among them, the rotational speed change diagnosis method is based on the absolute difference in the engine speed before and after the fuel injector fault diagnosis, and the cyclic fuel supply amount change diagnosis method is based on the absolute difference in the engine cyclic fuel supply amount before and after the fuel injector fault diagnosis.

[0080] The storage medium may adopt any combination of one or more computer-readable media. The computer-readable media may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer-readable storage medium may be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device.

[0081] The computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable program code. Such a propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium may also be any computer-readable medium other than the computer-readable storage medium, and this computer-readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0082] The computer program code for performing the operations of the present invention may be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages - such as the "C" language or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (for example, by using an Internet service provider to connect through the Internet).

[0083] An engine injector fault diagnosis device provided by an embodiment of the present invention includes a determination module and a diagnosis module.

[0084] The determination module is used to determine whether to enter the fuel injector fault diagnosis mode based on the fuel injector diagnosis requirements and in combination with the current vehicle state; the diagnosis module is used to select the engine speed change diagnosis method or the cyclic fuel supply change diagnosis method to implement fuel injector fault diagnosis when entering the fuel injector fault diagnosis mode; among them, the engine speed change diagnosis method is based on the absolute difference in the engine speed before and after fuel injector fault diagnosis, and the cyclic fuel supply change diagnosis method is based on the absolute difference in the engine cyclic fuel supply before and after fuel injector fault diagnosis.

[0085] In the present invention, based on the fuel injector diagnosis requirements and in combination with the current vehicle state, to determine whether to enter the fuel injector fault diagnosis mode, the specific process includes:

[0086] Create an engine diagnostic device for connecting to the engine's ECU, and send a fuel injector diagnosis requirement signal to the ECU through the engine diagnostic device;

[0087] The ECU receives the fuel injector diagnosis requirement signal, obtains the current vehicle state, and determines whether to enter the fuel injector fault diagnosis mode according to the obtained current vehicle state.

[0088] In the present invention, the current vehicle state includes the vehicle speed information, clutch state, brake state, and engine state.

[0089] In the present invention, when the vehicle speed is less than the set safety value, the clutch state is disengaged, the brake state is activated, and the engine is in the running state, then enter the fuel injector fault diagnosis mode; otherwise, do not enter the fuel injector fault diagnosis mode or exit the fuel injector fault diagnosis mode.

[0090] In the present invention,

[0091] For the engine speed change diagnosis method, the specific diagnosis steps include:

[0092] Send the engine cyclic fuel supply requirement to the ECU through the engine diagnostic device;

[0093] Based on the cyclic fuel injection amount in the engine cyclic fuel supply requirement, the fuel injectors of each cylinder of the engine inject fuel, and obtain the engine speed, which is used as the engine speed before fuel injector fault diagnosis;

[0094] The engine diagnostic device sends the cylinder number of the current fuel injector to be diagnosed to the ECU, and the ECU controls the current fuel injector to stop injecting fuel, and obtains the engine speed at this time, which is used as the engine speed after fuel injector fault diagnosis;

[0095] Judge whether the absolute difference between the engine speed after fuel injector fault diagnosis and the engine speed before fuel injector fault diagnosis is less than the set allowable engine speed fluctuation value:

[0096] If so, it indicates that the current fuel injector has a fault;

[0097] If not, it indicates that the current fuel injector is operating normally.

[0098] In the present invention, the allowable fluctuation value of the engine speed is set according to the vehicle model, and for engines with the same model, the set allowable fluctuation value of the engine speed is the same.

[0099] In the present invention, for the diagnostic method of the cyclic fuel supply quantity change, the specific diagnostic steps include:

[0100] Send the engine target speed demand to the ECU through the engine diagnostic device, and the engine operates according to the target speed in the engine target speed demand;

[0101] Self-regulate the cyclic fuel supply quantity demand through PID, and take the engine cyclic fuel supply quantity at this time as the engine cyclic fuel supply quantity before fuel injector fault diagnosis;

[0102] The engine diagnostic device sends the cylinder number of the current fuel injector to be diagnosed to the ECU, the ECU controls the current fuel injector to stop fuel injection, and obtains the engine cyclic fuel supply quantity at this time as the engine cyclic fuel supply quantity after fuel injector fault diagnosis;

[0103] Judge whether the absolute difference between the engine cyclic fuel supply quantity before fuel injector fault diagnosis and the engine cyclic fuel supply quantity after fuel injector fault diagnosis is less than the set allowable fluctuation value of the engine cyclic fuel supply quantity:

[0104] If so, it indicates that the current fuel injector is faulty;

[0105] If not, it indicates that the current fuel injector is operating normally.

[0106] In the present invention, the allowable fluctuation value of the engine cyclic fuel supply quantity is set according to the vehicle model, and for engines with the same model, the set allowable fluctuation value of the engine cyclic fuel supply quantity is the same.

[0107] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

[0108] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce means for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

Claims

1. A method for diagnosing faults in an engine injector, characterized in that, Specifically, it includes the following steps: Based on the injector diagnosis requirements and combined with the current vehicle state, determine whether to enter the injector fault diagnosis mode; When entering the injector fault diagnosis mode, select the engine speed change diagnosis method or the cyclic fuel supply change diagnosis method to implement the injector fault diagnosis; Among them, the engine speed change diagnosis method is based on the absolute difference in the engine speed before and after the injector fault diagnosis, and the cyclic fuel supply change diagnosis method is based on the absolute difference in the engine cyclic fuel supply before and after the injector fault diagnosis; Among them, the specific steps of determining whether to enter the injector fault diagnosis mode based on the injector diagnosis requirements and combined with the current vehicle state include: Create an engine diagnostic device for connecting to the engine's ECU, and send an injector diagnosis requirement signal to the ECU through the engine diagnostic device; The ECU receives the injector diagnosis requirement signal, obtains the current vehicle state, and determines whether to enter the injector fault diagnosis mode according to the obtained current vehicle state; Among them, for the cyclic fuel supply change diagnosis method, the specific diagnosis steps include: Send the engine target speed requirement to the ECU through the engine diagnostic device, and the engine operates at the target speed in the engine target speed requirement; Self-regulate the cyclic fuel supply requirement through PID and use the engine cyclic fuel supply at this time as the engine cyclic fuel supply before the injector fault diagnosis; The engine diagnostic device sends the cylinder number of the current injector to be diagnosed to the ECU, and the ECU controls the current injector to stop fuel injection, and obtains the engine cyclic fuel supply at this time as the engine cyclic fuel supply after the injector fault diagnosis; Judge whether the absolute difference between the engine cyclic fuel supply before the injector fault diagnosis and the engine cyclic fuel supply after the injector fault diagnosis is less than the set allowable fluctuation value of the engine cyclic fuel supply: If so, it indicates that the current injector is faulty; If not, it indicates that the current injector is operating normally.

2. The method for diagnosing faults of an engine injector according to claim 1, wherein: The current vehicle state includes the vehicle speed information, clutch state, brake state, and engine state.

3. The method for diagnosing an engine injector fault according to claim 2, wherein: When the vehicle speed is less than the set safety value, the clutch state is disengaged, the brake state is activated, and the engine is in the running state, enter the injector fault diagnosis mode; otherwise, do not enter the injector fault diagnosis mode or exit the injector fault diagnosis mode.

4. The method for diagnosing an engine injector fault according to claim 1, wherein, For the engine speed change diagnosis method, the specific diagnosis steps include: Send the engine cyclic fuel supply requirement to the ECU through the engine diagnostic device; Based on the cyclic fuel injection volume in the engine cyclic fuel supply requirement, the fuel injectors of each cylinder of the engine inject fuel, and obtain the engine speed as the engine speed before the injector fault diagnosis; The engine diagnostic device sends the cylinder number of the current injector to be diagnosed to the ECU, and the ECU controls the current injector to stop fuel injection, and obtains the engine speed at this time as the engine speed after the injector fault diagnosis; Judge whether the absolute difference between the engine speed after the injector fault diagnosis and the engine speed before the injector fault diagnosis is less than the set allowable fluctuation value of the engine speed: If so, it indicates that the current injector is faulty; If not, it indicates that the current fuel injector is operating normally.

5. The method for diagnosing an engine injector fault according to claim 4, wherein: The allowable fluctuation value of the engine speed is set according to the vehicle model, and for engines of the same model, the set allowable fluctuation value of the engine speed is the same.

6. The method for diagnosing the fault of an engine injector according to claim 1, characterized in that: The allowable fluctuation value of the engine's cyclic fuel supply is set according to the vehicle model, and for engines of the same model, the set allowable fluctuation value of the engine's cyclic fuel supply is the same.

7. A readable storage medium, characterized in that, The readable storage medium is located in the PLC controller. A computer program is stored on the readable storage medium, and when the program is executed by the processor, it implements the engine fuel injector fault diagnosis method according to any one of claims 1 to 6.

8. An engine injector engine diagnostic device, characterized in that, Including: A determination module for determining whether to enter the fuel injector fault diagnosis mode based on the fuel injector diagnosis requirements and in combination with the current state of the vehicle. A diagnosis module for, when entering the fuel injector fault diagnosis mode, selecting the engine speed change diagnosis method or the cyclic fuel supply change diagnosis method to implement fuel injector fault diagnosis. Among them, the engine speed change diagnosis method is based on the absolute difference in the engine speed before and after fuel injector fault diagnosis, and the cyclic fuel supply change diagnosis method is based on the absolute difference in the engine's cyclic fuel supply before and after fuel injector fault diagnosis. Among them, the specific steps for determining whether to enter the fuel injector fault diagnosis mode based on the fuel injector diagnosis requirements and in combination with the current state of the vehicle include: Create an engine diagnostic device for connecting to the ECU of the engine, and send a fuel injector diagnosis requirement signal to the ECU through the engine diagnostic device. The ECU receives the fuel injector diagnosis requirement signal, obtains the current state of the vehicle, and determines whether to enter the fuel injector fault diagnosis mode according to the obtained current state of the vehicle. Among them, for the cyclic fuel supply change diagnosis method, the specific diagnosis steps include: Send the engine target speed requirement to the ECU through the engine diagnostic device, and the engine operates at the target speed in the engine target speed requirement. Self-regulate the cyclic fuel supply requirement through PID and use the engine's cyclic fuel supply at this time as the engine's cyclic fuel supply before fuel injector fault diagnosis. The engine diagnostic device sends the cylinder number of the current fuel injector to be diagnosed to the ECU, and the ECU controls the current fuel injector to stop fuel injection and obtains the engine's cyclic fuel supply at this time as the engine's cyclic fuel supply after fuel injector fault diagnosis. Judge whether the absolute difference between the engine's cyclic fuel supply before fuel injector fault diagnosis and the engine's cyclic fuel supply after fuel injector fault diagnosis is less than the set allowable fluctuation value of the engine's cyclic fuel supply: If so, it indicates that the current fuel injector is faulty. If not, it indicates that the current fuel injector is operating normally.

Images