A method and device for diagnosing fuel quantity deviation of a fuel injector

Abstract

The present invention relates to a method and device for diagnosing fuel quantity deviation of a fuel injector, and belongs to the technical field of fuel quantity diagnosis of fuel injectors. The method comprises: judging the injection quantity of each cylinder based on the rack-rail pressure of all rack-rail pressures of each cylinder when a crankshaft gear plate rotates, without judging by a change in engine speed; further, obtaining the rack-rail pressure of at least two gear teeth corresponding to each cylinder in each cycle of rotation of the crankshaft gear plate, obtaining a corresponding rack-rail pressure drop difference based on the rack-rail pressure of at least two gear teeth corresponding to each cylinder, determining a target cylinder corresponding to each cycle based on the rack-rail pressure drop difference, determining a faulty cylinder based on all target cylinders in all cycles, performing anti-shake counting based on the rack-rail pressure drop difference of the faulty cylinder to obtain a count value, outputting a diagnosis result of the fuel quantity of the faulty cylinder, and diagnosing the fault of each cylinder on the crankshaft gear plate in the current cycle in combination with the cycles that have been executed, thereby improving the accuracy of the diagnosis result.

Description

Technical Field

[0001] The present invention relates to the technical field of injector oil quantity diagnosis, and in particular to a method and device for diagnosing injector oil quantity deviation. Background Art

[0002] The injection control strategy of existing high-pressure common rail fuel systems is generally as follows: the required injection quantity is calculated based on engine speed, coolant temperature, and load. The injection pulse width (i.e., the injector opening time) required to inject the set fuel quantity at the current rail pressure level is then calculated based on the injector's injection characteristics. The ECU drives the injector to open at the appropriate timing for the set injection pulse width, injecting the desired amount of fuel into the cylinder for combustion. This injection control strategy lacks injection quantity feedback, preventing the control software from determining the actual injection quantity and making corrections. Excessive or insufficient actual injection quantity can result in adverse consequences such as excessive vehicle vibration and poor emissions, necessitating diagnosis of injection quantity deviation faults.

[0003] In the prior art, when diagnosing individual injector injection quantity deviation, wear (or clogging) of the injector can cause the fuel injection quantity to be higher (or lower) than the set value. This means that the amount of fuel entering the cylinder for combustion is higher (or lower). Consequently, the speed change caused by combustion in the faulty cylinder is higher (or lower) than that of other normal cylinders. Prior art solutions determine individual injection quantity deviation by calculating the speed deviation between each cylinder's corresponding speed and the average speed of all cylinders. If the injection quantity in a cylinder is too high, the speed deviation is positive; if the injection quantity in a cylinder is too low, the speed deviation is negative. When the speed deviation in a cylinder is greater than the upper deviation limit (or less than the lower deviation limit), it is determined that the injector in that cylinder has an excessive (or insufficient) injection quantity fault. However, in prior art, engine speed changes are dependent on combustion, and the intermediate process from injection to speed change is lengthy, consisting of multiple processes: injection, combustion, and the conversion of energy into kinetic energy on the piston. This leads to numerous interference factors, making accurate fault diagnosis difficult.

[0004] Therefore, it is urgent to propose a method and device for diagnosing fuel quantity deviation of injector to solve the technical problem that the intermediate process from fuel injection to speed change in the existing technology is long, resulting in many interference factors in the process of judging the fuel injection quantity deviation through engine speed change, making it difficult to accurately diagnose the fault. Summary of the Invention

[0005] In view of this, it is necessary to provide a method and device for diagnosing fuel quantity deviation of injector to solve the technical problem in the prior art that the intermediate process from fuel injection to speed change is long, resulting in many interference factors in the process of judging the fuel injection quantity deviation through engine speed change, making it difficult to accurately diagnose faults.

[0006] In order to solve the above problems, the present invention provides a method for diagnosing fuel quantity deviation of an injector, comprising:

[0007] When the crankshaft gear plate rotates one cycle, the rack pressure of at least two gear teeth corresponding to each cylinder on the crankshaft gear plate is obtained; the gear teeth and the rack pressure correspond one to one;

[0008] Obtaining a rail pressure drop difference corresponding to each cylinder according to the rack-rail pressure, and determining a target cylinder for the current cycle according to the rail pressure drop difference;

[0009] Determine the faulty cylinder based on all target cylinders in all cycles;

[0010] Anti-shake counting is performed according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and a diagnosis result of the fuel injection amount of the faulty cylinder is output according to the count value.

[0011] In a possible implementation, obtaining the rack-rail pressure of at least one gear tooth corresponding to each cylinder on the crankshaft gear plate includes:

[0012] Determining at least two gear teeth corresponding to each cylinder on the crankshaft gear disc according to a preset acquisition range;

[0013] The rack pressure of each gear tooth is obtained according to the at least one gear tooth of each cylinder.

[0014] In a possible implementation, obtaining the rail pressure drop difference corresponding to each cylinder according to the rack-rail pressure includes:

[0015] Calculating the difference in rack-rail pressure between two adjacent gear teeth on each cylinder to obtain a rack-rail pressure difference corresponding to each gear tooth on each cylinder;

[0016] According to all rack-rail pressure difference values ​​corresponding to each cylinder, a maximum continuous rail pressure drop corresponding to each cylinder is obtained;

[0017] The rail pressure drop difference corresponding to each cylinder is obtained according to all the maximum continuous rail pressure drops of all the cylinders on the crankshaft gear plate.

[0018] In a possible implementation, obtaining the maximum continuous rail pressure drop corresponding to each cylinder according to all rack-rail pressure difference values ​​corresponding to each cylinder includes:

[0019] respectively determining whether all the rack-rail pressure differential values ​​corresponding to each cylinder are positive;

[0020] If yes, then all the rack-rail pressure difference values ​​are accumulated to obtain the corresponding maximum continuous rail pressure drop;

[0021] If not, the rack rail pressure difference values ​​that are consecutively positive among all the rack rail pressure difference values ​​are accumulated to obtain multiple rack rail pressure difference accumulated values, and the maximum value among the multiple rack rail pressure difference accumulated values ​​is determined as the corresponding maximum continuous rail pressure drop.

[0022] In a possible implementation, the crankshaft gear plate includes a first cylinder and other cylinders, and obtaining the rail pressure drop difference corresponding to each cylinder based on all maximum continuous rail pressure drops of all cylinders on the crankshaft gear plate includes:

[0023] determining an average value of maximum continuous rail pressure drops of the cylinders other than the first cylinder on the crankshaft gear plate to obtain an average rail pressure drop value;

[0024] The rail pressure drop difference corresponding to the first cylinder is obtained by subtracting the rail pressure drop average value from the maximum continuous rail pressure drop of the first cylinder.

[0025] In a possible implementation, determining the faulty cylinder based on all target cylinders in all cycles includes:

[0026] Obtaining a total number of times according to all the cycles of rotation of the crankshaft gear plate;

[0027] Determining a target number of times each cylinder is a target cylinder based on all the target cylinders;

[0028] The faulty cylinder is determined according to the total number of times and the target number of times corresponding to each cylinder.

[0029] In a possible implementation, determining the faulty cylinder according to the total number of times and the target number of times corresponding to each cylinder includes:

[0030] When the total number of times is greater than a first preset threshold, determining the cylinder corresponding to the maximum value among all target times as the initial fault cylinder;

[0031] Determining whether a ratio of the target number of times of the initial faulty cylinder to the total number of times is greater than a preset ratio threshold;

[0032] If so, it is determined that the initial fault cylinder is a fault cylinder.

[0033] In a possible implementation, performing anti-shake counting based on the rail pressure drop difference of the faulty cylinder to obtain a count value, and outputting a diagnosis result of the fuel injection amount of the faulty cylinder based on the count value includes:

[0034] The rail pressure drop difference of the fault cylinder is judged according to a preset high oil volume diagnostic threshold and a preset low oil volume diagnostic threshold to obtain a judgment result;

[0035] The total number of times is updated according to the judgment result to obtain a count value;

[0036] When the count value is greater than a second preset threshold, a diagnosis result of a fuel injection quantity fault of the faulty cylinder is obtained.

[0037] In a possible implementation, determining the target cylinder of the current cycle according to the rail pressure drop difference includes:

[0038] The cylinder corresponding to the maximum absolute value of the rail pressure drop difference in the current cycle is determined as the target cylinder.

[0039] On the other hand, the present invention also provides a device for diagnosing fuel quantity deviation of an injector, comprising:

[0040] A rack pressure acquisition module is used to acquire the rack pressure of at least one gear tooth corresponding to each cylinder on the crankshaft gear plate when the crankshaft gear plate rotates one cycle; the gear teeth and the rack pressure correspond one to one;

[0041] a target cylinder determination module, configured to obtain a rail pressure drop difference corresponding to each cylinder according to the rack-rail pressure, and determine a target cylinder for the current cycle according to the rail pressure drop difference;

[0042] A fault cylinder determination module is used to determine the fault cylinder based on all target cylinders in all cycles;

[0043] The result determination module is used to perform anti-shake counting according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and output a diagnosis result of the fuel injection amount of the faulty cylinder according to the count value.

[0044] The beneficial effects of the present invention are as follows: the injection amount of each cylinder is judged according to the rack-rail pressure of all rack-rail pressures of each cylinder when the crankshaft sprocket rotates, and there is no need to judge according to the change of engine speed, which can avoid interference from other factors; further, the rack-rail pressure of at least two gear teeth corresponding to each cylinder can be obtained in each cycle of the crankshaft sprocket rotation, so that the corresponding rack-rail pressure drop difference can be obtained according to the rack-rail pressure of at least two gear teeth corresponding to each cylinder, and then the target cylinder corresponding to each cycle can be determined according to the rack-rail pressure drop difference, so that the fault cylinder can be determined according to all target cylinders in all cycles, and anti-shake counting is performed according to the rack-rail pressure drop difference of the faulty cylinder to obtain a count value, so that the diagnosis result of the injection amount of the faulty cylinder can be output according to the count value, and the fault of each cylinder on the crankshaft sprocket can be diagnosed in the current cycle in combination with the cycle that has been executed, avoiding interference from other influencing factors in the intermediate process and improving the accuracy of the diagnosis result. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic flow chart of an embodiment of a method for diagnosing fuel quantity deviation in a fuel injector provided by the present invention;

[0046] Figure 2 For the present invention Figure 1 A schematic flow chart of an embodiment of step S102;

[0047] Figure 3 For the present invention Figure 2 A schematic flow chart of an embodiment of step S202;

[0048] Figure 4 For the present invention Figure 1 A schematic flow chart of an embodiment of step S103;

[0049] Figure 5 For the present invention Figure 4 A schematic flow chart of an embodiment of step S403;

[0050] Figure 6 For the present invention Figure 1 A schematic flow chart of an embodiment of step S104;

[0051] Figure 7 A schematic structural diagram of an embodiment of the device for diagnosing fuel quantity deviation in a fuel injector provided by the present invention;

[0052] Figure 8 This is a schematic structural diagram of an embodiment of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0053] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0054] like Figure 1 As shown, a specific embodiment of the present invention discloses a method for diagnosing fuel quantity deviation of an injector, comprising:

[0055] S101. When the crankshaft gear plate rotates one cycle, the rack pressure of at least two gear teeth corresponding to each cylinder on the crankshaft gear plate is obtained; the gear teeth and the rack pressure correspond one to one;

[0056] S102, obtaining a rail pressure drop difference corresponding to each cylinder according to the rack-rail pressure, and determining a target cylinder for the current cycle according to the rail pressure drop difference;

[0057] S103, determining a faulty cylinder based on all target cylinders in all cycles;

[0058] S104 , performing anti-shake counting according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and outputting a diagnosis result of the fuel injection amount of the faulty cylinder according to the count value.

[0059] The embodiments of the present invention can be applied to a high-pressure common rail fuel system of a diesel engine. In the high-pressure common rail fuel system of a diesel engine, fuel in the fuel rail is injected into the cylinder, causing the rail pressure to drop. The present invention can determine the fuel quantity deviation of each cylinder's injector based on the magnitude of the rail pressure drop during injection. Specifically, the rack-rail pressure of at least one gear tooth corresponding to each cylinder during one crankshaft gear plate rotation cycle can be obtained. Since gear teeth correspond to rack-rail pressures one-to-one, the number of rack-rail pressures obtained is equal to the number of gear teeth. Based on the rack-rail pressures, the rail pressure drop difference corresponding to each cylinder can be obtained. For example, if the first cylinder has 20 gear teeth, there are 20 rack-rail pressures. Based on these 20 rack-rail pressures, the rail pressure drop difference for the first cylinder can be obtained. Furthermore, based on the rail pressure drop differences corresponding to all cylinders on the crankshaft gear plate, the target cylinder for the current crankshaft gear plate rotation cycle can be obtained. Based on all target cylinders in all cycles, the faulty cylinder can be determined. Anti-shake counting is then performed based on the rail pressure drop differences of the faulty cylinder to obtain a count value. Based on the count value, the fuel quantity diagnosis result for the faulty cylinder can be output. For example, if the faulty cylinder is cylinder 2, the fuel quantity fault diagnosis result for cylinder 2 can be output.

[0060] Compared with the prior art, the present embodiment provides a method for judging the injection quantity of each cylinder based on the rack-rail pressure of all rack-rail pressures of each cylinder when the crankshaft sprocket rotates, without the need for judging based on changes in engine speed, thus avoiding interference from other factors; further, the rack-rail pressure of at least one gear tooth corresponding to each cylinder can be obtained in each cycle of the crankshaft sprocket rotation, thereby obtaining a corresponding rack-rail pressure drop difference based on the rack-rail pressure of at least one gear tooth corresponding to each cylinder, and then determining the target cylinder corresponding to each cycle based on the rack-rail pressure drop difference, thereby determining the faulty cylinder based on all target cylinders in all cycles, performing anti-shake counting based on the rack-rail pressure drop difference of the faulty cylinder to obtain a count value, and outputting a diagnostic result of the fuel injection quantity of the faulty cylinder based on the count value, and thereby diagnosing the fault of each cylinder on the crankshaft sprocket in the current cycle in combination with the cycles that have been executed, thus avoiding interference from other influencing factors in the intermediate process and improving the accuracy of the diagnostic result.

[0061] In some embodiments of the present invention, step S101 includes:

[0062] Determine at least two gear teeth corresponding to each cylinder on the crankshaft gear disc according to a preset acquisition range;

[0063] According to at least one gear tooth of each cylinder, the rack pressure of each gear tooth is obtained.

[0064] In a specific embodiment of the present invention, a preset collection range can be set. For example, for a six-cylinder engine with a 60-tooth crankshaft sprocket, two crankshaft sprocket rotations constitute one cycle. Therefore, each cylinder has 20 teeth. With tooth number X as the starting tooth for rail pressure collection, the range from tooth X to tooth X+19 constitutes the rack-rail pressure collection range for a particular cylinder, and the range from tooth X+20 to tooth X+39 for the next cylinder. This range is analogous to the range for each of the six cylinders. The preset collection range can be set based on actual conditions and is not limited in this embodiment. After determining that each cylinder corresponds to at least one gear tooth, the gear pressure for each gear tooth can be acquired based on the data collected during crankshaft sprocket rotation.

[0065] In some embodiments of the present invention, Figure 2 As shown, step S102 includes:

[0066] S201, calculating the difference in rack-rail pressure between two adjacent gear teeth on each cylinder to obtain a rack-rail pressure difference corresponding to each gear tooth on each cylinder;

[0067] S202, obtaining the maximum continuous rail pressure drop corresponding to each cylinder based on all rack-rail pressure difference values ​​corresponding to each cylinder;

[0068] S203 : Obtain a rail pressure drop difference corresponding to each cylinder based on all maximum continuous rail pressure drops of all cylinders on the crankshaft gear plate.

[0069] In a specific embodiment of the present invention, the rack pressure difference between two adjacent gear teeth on each cylinder can be calculated. For example, the gear teeth of cylinder No. 1 are from tooth X to tooth X+19, so the rack pressure difference between teeth X and X+1 is calculated. Similarly, a total of 19 rack pressure difference values ​​between two adjacent teeth from teeth X to X+19 are calculated. Similarly, the rack pressure difference values ​​of other cylinders can be calculated, and all rack pressure difference values ​​of other cylinders can be obtained.

[0070] In some embodiments of the present invention, Figure 3 As shown, step S202 includes:

[0071] S301, respectively determining whether all rack-rail pressure differential values ​​corresponding to each cylinder are positive;

[0072] S302: If yes, then add up all rack-rail pressure difference values ​​to obtain the corresponding maximum continuous rail pressure drop;

[0073] S303: If not, summing up all the rack-rail pressure difference values ​​that are consecutively positive to obtain a plurality of rack-rail pressure difference accumulation values, and determining the maximum value among the plurality of rack-rail pressure difference accumulation values ​​as the corresponding maximum continuous rail pressure drop.

[0074] In a specific embodiment of the present invention, all rack-rail pressure difference values ​​corresponding to each cylinder can be judged to determine whether they are all positive values. A positive rack-rail pressure difference value indicates a decrease in rail pressure, and a negative difference indicates an increase in rail pressure. The maximum continuous rail pressure drop amplitude within this range is calculated, that is, the maximum continuous rail pressure drop of this cylinder. The calculation method is: starting from the rack-rail pressure difference value from X to X+1 and ending with the rack-rail pressure difference value from X+18 to X+19, if the rack-rail pressure difference value is positive, then accumulate; if the rack-rail pressure difference value is negative, then record the current rack-rail pressure difference value accumulation value, and start accumulating from 0 the next time the rack-rail pressure difference value is positive again. After all 19 rack-rail pressure difference values ​​are accumulated, take out the maximum value of all recorded rack-rail pressure difference value accumulation values, and this maximum value is the maximum continuous rail pressure drop amplitude of this cylinder. Similarly, the maximum continuous rail pressure drop amplitude of each of the six cylinders is calculated. For example, assuming that the rack pressure of X to X+19 teeth of cylinder No. 1 is shown in Table 1:

[0075] Table 1, X to X+19 rack rail pressure

[0076]

[0077] The rack rail pressure difference calculated based on the rack rail pressure from X to X+19 in Table 1 is shown in Table 2:

[0078] Table 2, rack rail pressure difference value

[0079]

[0080] Calculate the rail pressure drop: If the pressure differential between racks X and X+4 is positive, the rail pressure drop is 5+5+5+5=20 bar. If the pressure differential between racks X+4 and X+5 is negative, the rail pressure drop starts again from 0: If the pressure differential between racks X+5 and X+10 is positive, the rail pressure drop is 5+5+5+5+25=45 bar. Similarly, the rail pressure drop between racks X+11 and X+13 is 10 bar, and the rail pressure drop between racks X+15 and X+19 is 15 bar. The calculated rail pressure drops are 20 bar, 45 bar, 10 bar, and 15 bar. Taking the maximum value of 45 bar, the maximum rail pressure drop between racks X and X+19 is 45 bar. Similarly, the maximum rail pressure drop for each cylinder can be calculated using the same method.

[0081] In some embodiments of the present invention, the crankshaft gear plate includes a first cylinder and other cylinders, and step S203 includes:

[0082] Determine the average value of the maximum continuous rail pressure drops of the cylinders other than the first cylinder on the crankshaft gear plate to obtain the average rail pressure drop value;

[0083] The rail pressure drop difference corresponding to the first cylinder is obtained by subtracting the average rail pressure drop from the maximum continuous rail pressure drop of the first cylinder.

[0084] In a specific embodiment of the present invention, the rail pressure drop difference for each cylinder can be calculated. A specific calculation method may include: determining any cylinder on the crankshaft sprocket as the first cylinder, and the other cylinders except the first cylinder as the other cylinders. Then, the average of the maximum continuous rail pressure drops of the other cylinders on the crankshaft sprocket, except the first cylinder, can be calculated to obtain the average rail pressure drop. Specifically, the maximum continuous rail pressure drops of each cylinder are summed, subtracted from the rail pressure drop difference of the first cylinder, and divided by the total number of cylinders - 1 to obtain the average rail pressure drop for the first cylinder. The rail pressure drop difference corresponding to the first cylinder can then be subtracted from the average rail pressure drop of the first cylinder to obtain the rail pressure drop difference for the first cylinder. Similarly, the rail pressure drop difference corresponding to each other cylinder can be obtained using the above method, thereby obtaining the rail pressure drop difference for each cylinder on the crankshaft sprocket. A positive rail pressure drop difference indicates that the rail pressure drop of this cylinder is greater than that of other cylinders, i.e., the fuel injection amount of this cylinder is relatively large; a negative rail pressure drop difference indicates that the rail pressure drop of this cylinder is less than that of other cylinders, i.e., the fuel injection amount of this cylinder is relatively small. The larger the absolute value of the rail pressure drop difference, the greater the deviation of the cylinder injection amount.

[0085] In some embodiments of the present invention, step S102 includes:

[0086] The cylinder corresponding to the maximum absolute value of the rail pressure drop difference in the current cycle is determined as the target cylinder.

[0087] In a specific embodiment of the present invention, in the current cycle of rotation of the crankshaft gear, the cylinder with the maximum absolute value of the rail pressure drop difference corresponding to each cylinder can be determined as the target cylinder. For example, among the six cylinders, the absolute value of the rail pressure drop difference of cylinder No. 1 is the largest, so cylinder No. 1 can be determined as the target cylinder.

[0088] In some embodiments of the present invention, Figure 4 As shown, step S103 includes:

[0089] S401, obtaining a total number of times according to all cycles of crankshaft gear rotation;

[0090] S402, determining a target number of times each cylinder is a target cylinder based on all target cylinders;

[0091] S403: Determine the faulty cylinder according to the total number of times and the target number of times corresponding to each cylinder.

[0092] In a specific embodiment of the present invention, the total number of times can be obtained based on all cycles of rotation of the crankshaft gear. For example, if the crankshaft gear rotates 100 cycles, the total number of times can be determined to be 100. There are also 100 target cylinders, and then the target number of times corresponding to each cylinder in the 100 target cylinders can be determined. For example, the target cylinder is cylinder No. 1 for 40 times, the target cylinder is cylinder No. 2 for 5 times, the target cylinder is cylinder No. 3 for 5 times, the target cylinder is cylinder No. 4 for 30 times, the target cylinder is cylinder No. 5 for 10 times, and the target cylinder is cylinder No. 6 for 10 times. Then, the faulty cylinder can be determined based on the total number of times and the target number of times corresponding to each cylinder.

[0093] In some embodiments of the present invention, Figure 5 As shown, step S403 includes:

[0094] S501: When the total number of times is greater than a first preset threshold, determine the cylinder corresponding to the maximum value among all target numbers as the initial fault cylinder;

[0095] S502: Determine whether the ratio of the target number of initial failure cylinders to the total number of failures is greater than a preset ratio threshold;

[0096] S503: If yes, determine that the initial faulty cylinder is a faulty cylinder.

[0097] In a specific embodiment of the present invention, the total number of times can be determined to determine whether it is greater than a first preset threshold. If so, the cylinder corresponding to the maximum value among all target times can be determined as the initial faulty cylinder. For example, if the target cylinder is cylinder 1 with 40 times, the target cylinder is cylinder 2 with 5 times, the target cylinder is cylinder 3 with 5 times, the target cylinder is cylinder 4 with 30 times, the target cylinder is cylinder 5 with 10 times, and the target cylinder is cylinder 6 with 10 times, cylinder 1 has the largest target number of times, and cylinder 1 can be determined to be the initial faulty cylinder. Then, the ratio of the target number of times for cylinder 1 to the total number of times (40 / 100) can be calculated to determine whether the ratio of the target number of times to the total number of times is greater than a preset ratio threshold. If so, cylinder 1 can be determined to be the faulty cylinder. If not, the next cycle is performed. The first preset threshold and the preset ratio threshold can be set according to actual conditions and are not limited in this embodiment of the present invention.

[0098] In some embodiments of the present invention, Figure 6 As shown, step S104 includes:

[0099] S601: Determine the rail pressure drop difference of the faulty cylinder based on a preset high oil volume diagnostic threshold and a preset low oil volume diagnostic threshold to obtain a determination result;

[0100] S602: Update the total number of times according to the judgment result to obtain a count value;

[0101] S603: When the count value is greater than the second preset threshold, a diagnosis result of a fuel injection quantity fault of the faulty cylinder is obtained.

[0102] In a specific embodiment of the present invention, a preset excessive fuel volume diagnostic threshold and a preset insufficient fuel volume diagnostic threshold can be set according to actual conditions. The specific preset excessive fuel volume diagnostic threshold and the preset insufficient fuel volume diagnostic threshold are not limited in the present embodiment. It can be determined whether the rail pressure drop difference of the faulty cylinder is greater than the preset excessive fuel volume diagnostic threshold or less than the preset insufficient fuel volume diagnostic threshold. If so, an anti-shake count is started. After each time a certain period of time passes or a cycle is completed, the total number of times is increased by one. If not, after each time a certain period of time passes or a cycle is completed, the total number of times is decreased by one, and the updated count value is obtained. Then, it can be determined whether the count value is greater than a second preset threshold. If so, a fuel injection fault of the corresponding cylinder can be reported to obtain a diagnostic result, for example, a fuel injection fault of cylinder No. 1.

[0103] Furthermore, considering factors such as the starting position of rack pressure collection, the cylinder number update position, and the scheduling position of this diagnostic function, the cylinder number with the largest deviation and the actual fault cylinder number need to be calibrated to ensure that the fault cylinder number reported in the end is correct.

[0104] In order to better implement the injector oil quantity deviation diagnosis method in the embodiment of the present invention, based on the injector oil quantity deviation diagnosis method, the embodiment of the present invention also provides an injector oil quantity deviation diagnosis device, such as Figure 7 As shown, the injector oil quantity deviation diagnostic device 700 includes:

[0105] The rack pressure acquisition module 701 is used to acquire the rack pressure of at least two gear teeth corresponding to each cylinder on the crankshaft gear plate when the crankshaft gear plate rotates one cycle; the gear teeth and the rack pressure correspond one to one;

[0106] The target cylinder determination module 702 is configured to obtain the rail pressure drop difference corresponding to each cylinder according to the rack rail pressure, and determine the target cylinder of the current cycle according to the rail pressure drop difference;

[0107] A fault cylinder determination module 703 is configured to determine a fault cylinder based on all target cylinders in all cycles;

[0108] The result determination module 704 is configured to perform anti-shake counting according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and output a diagnosis result of the fuel injection amount of the faulty cylinder according to the count value.

[0109] The injector oil quantity deviation diagnostic device 700 provided in the above embodiment can implement the technical solution described in the above injector oil quantity deviation diagnostic method embodiment. The specific implementation principles of the above modules or units can be found in the corresponding contents in the above injector oil quantity deviation diagnostic method embodiment, which will not be repeated here.

[0110] like Figure 8 As shown, the present invention also provides an electronic device 800. The electronic device 800 includes a processor 801, a memory 802 and a display 803. Figure 8 Only some of the components of the electronic device 800 are shown, but it should be understood that implementation of all of the shown components is not required, and more or fewer components may be implemented instead.

[0111] In some embodiments, the memory 802 may be an internal storage unit of the electronic device 800, such as a hard disk or memory of the electronic device 800. In other embodiments, the memory 802 may also be an external storage device of the electronic device 800, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 800.

[0112] Furthermore, the memory 802 may include both an internal storage unit of the electronic device 800 and an external storage device. The memory 802 is used to store application software installed in the electronic device 800 and various data.

[0113] In some embodiments, the processor 801 may be a central processing unit (CPU), a microprocessor, or other data processing chip, configured to execute program codes or process data stored in the memory 802 , such as the injector oil quantity deviation diagnosis method of the present invention.

[0114] In some embodiments, display 803 can be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 803 is used to display information about electronic device 800 and to display a visual user interface. Components 801-803 of electronic device 800 communicate with each other via a system bus.

[0115] In some embodiments of the present invention, when the processor 801 executes the injector oil quantity deviation diagnostic program in the memory 802, the following steps may be implemented:

[0116] When the crankshaft gear plate rotates one cycle, the rack pressure of at least two gear teeth corresponding to each cylinder on the crankshaft gear plate is obtained; the gear teeth and the rack pressure correspond one to one;

[0117] The rail pressure drop difference corresponding to each cylinder is obtained according to the rack rail pressure, and the target cylinder of the current cycle is determined according to the rail pressure drop difference;

[0118] Determine the faulty cylinder based on all target cylinders in all cycles;

[0119] Anti-shake counting is performed according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and a diagnosis result of the fuel injection amount of the faulty cylinder is output according to the count value.

[0120] It should be understood that, when the processor 801 executes the injector oil quantity deviation diagnostic program in the memory 802 , in addition to the above functions, it can also implement other functions. For details, please refer to the description of the corresponding method embodiment above.

[0121] Furthermore, the embodiments of the present invention do not specifically limit the type of electronic device 800 mentioned. The electronic device 800 may be a portable electronic device such as a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, or laptop computer. Exemplary embodiments of portable electronic devices include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The portable electronic devices mentioned above may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 800 may not be a portable electronic device, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0122] Accordingly, an embodiment of the present application also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, the steps or functions of the injector oil quantity deviation diagnosis method provided in the above-mentioned method embodiments can be implemented.

[0123] Those skilled in the art will appreciate that all or part of the process flow of the above-described method embodiment can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0124] The above is a detailed introduction to the injector oil quantity deviation diagnosis method and device provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the method and core concept of the present invention. At the same time, for those skilled in the art, based on the concept of the present invention, there may be changes in the specific implementation method and application scope. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A method for diagnosing fuel quantity deviation of an injector, characterized in that: include: When the crankshaft gear plate rotates one cycle, the rack pressure of at least two gear teeth corresponding to each cylinder on the crankshaft gear plate is obtained; the gear teeth and the rack pressure correspond one to one; Obtaining a rail pressure drop difference corresponding to each cylinder according to the rack-rail pressure, and determining a target cylinder for the current cycle according to the rail pressure drop difference; Determine the faulty cylinder based on all target cylinders in all cycles; performing anti-shake counting according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and outputting a diagnosis result of the fuel injection amount of the faulty cylinder according to the count value; The obtaining of the rail pressure drop difference corresponding to each cylinder according to the rack-rail pressure includes: Calculating the difference in rack-rail pressure between two adjacent gear teeth on each cylinder to obtain a rack-rail pressure difference corresponding to each gear tooth on each cylinder; According to all rack-rail pressure difference values ​​corresponding to each cylinder, a maximum continuous rail pressure drop corresponding to each cylinder is obtained; Obtaining a rail pressure drop difference corresponding to each cylinder according to all maximum continuous rail pressure drops of all cylinders on the crankshaft gear plate; Obtaining the maximum continuous rail pressure drop corresponding to each cylinder based on all rack-rail pressure difference values ​​corresponding to each cylinder includes: respectively determining whether all the rack-rail pressure differential values ​​corresponding to each cylinder are positive; If yes, then all the rack-rail pressure difference values ​​are accumulated to obtain the corresponding maximum continuous rail pressure drop; If not, the rack rail pressure difference values ​​that are consecutively positive among all the rack rail pressure difference values ​​are accumulated to obtain multiple rack rail pressure difference accumulated values, and the maximum value among the multiple rack rail pressure difference accumulated values ​​is determined as the corresponding maximum continuous rail pressure drop.

2. The method for diagnosing fuel quantity deviation of a fuel injector according to claim 1, characterized in that: The obtaining of the rack-rail pressure of at least two gear teeth corresponding to each cylinder on the crankshaft gear plate includes: Determining at least two gear teeth corresponding to each cylinder on the crankshaft gear disc according to a preset acquisition range; The rack pressure of each gear tooth is obtained according to the at least one gear tooth of each cylinder.

3. The method for diagnosing fuel quantity deviation of a fuel injector according to claim 1, characterized in that: The crankshaft gear plate includes a first cylinder and other cylinders, and the rail pressure drop difference corresponding to each cylinder is obtained according to all maximum continuous rail pressure drops of all cylinders on the crankshaft gear plate, including: determining an average value of maximum continuous rail pressure drops of the cylinders other than the first cylinder on the crankshaft gear plate to obtain an average rail pressure drop value; The rail pressure drop difference corresponding to the first cylinder is obtained by subtracting the rail pressure drop average value from the maximum continuous rail pressure drop of the first cylinder.

4. The method for diagnosing fuel quantity deviation of a fuel injector according to claim 1, characterized in that: Determining the faulty cylinder based on all target cylinders in all cycles includes: Obtaining a total number of times according to all the cycles of rotation of the crankshaft gear plate; Determining a target number of times each cylinder is a target cylinder based on all the target cylinders; The faulty cylinder is determined according to the total number of times and the target number of times corresponding to each cylinder.

5. The method for diagnosing fuel quantity deviation of a fuel injector according to claim 4, characterized in that: The determining of the faulty cylinder according to the total number of times and the target number of times corresponding to each cylinder includes: When the total number of times is greater than a first preset threshold, determining the cylinder corresponding to the maximum value among all target times as the initial fault cylinder; Determining whether a ratio of the target number of times of the initial faulty cylinder to the total number of times is greater than a preset ratio threshold; If so, it is determined that the initial fault cylinder is a fault cylinder.

6. The method for diagnosing fuel quantity deviation of a fuel injector according to claim 4, characterized in that: The anti-shake counting is performed according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and the diagnosis result of the fuel injection amount of the faulty cylinder is output according to the count value, including: The rail pressure drop difference of the fault cylinder is judged according to a preset high oil volume diagnostic threshold and a preset low oil volume diagnostic threshold to obtain a judgment result; The total number of times is updated according to the judgment result to obtain a count value; When the count value is greater than a second preset threshold, a diagnosis result of a fuel injection quantity fault of the faulty cylinder is obtained.

7. The method for diagnosing fuel quantity deviation of a fuel injector according to claim 1, characterized in that: Determining the target cylinder of the current cycle according to the rail pressure drop difference includes: The cylinder corresponding to the maximum absolute value of the rail pressure drop difference in the current cycle is determined as the target cylinder.

8. A fuel injector oil quantity deviation diagnostic device, characterized in that: include: A rack pressure acquisition module is used to acquire the rack pressure of at least two gear teeth corresponding to each cylinder on the crankshaft gear disc when the crankshaft gear disc rotates one cycle; the gear teeth and the rack pressure correspond one to one; a target cylinder determination module, configured to obtain a rail pressure drop difference corresponding to each cylinder according to the rack-rail pressure, and determine a target cylinder for the current cycle according to the rail pressure drop difference; A fault cylinder determination module is used to determine the fault cylinder based on all target cylinders in all cycles; a result determination module, configured to perform anti-shake counting according to the rail pressure drop difference of the faulty cylinder to obtain a count value, and output a diagnosis result of the fuel injection amount of the faulty cylinder according to the count value; The target cylinder determination module is further configured to calculate the rack-rail pressure difference between two adjacent gear teeth on each cylinder to obtain a rack-rail pressure difference corresponding to each gear tooth on each cylinder; obtain a maximum continuous rail pressure drop corresponding to each cylinder based on all rack-rail pressure difference values ​​corresponding to each cylinder; and obtain a rail pressure drop difference corresponding to each cylinder based on all maximum continuous rail pressure drops of all cylinders on the crankshaft sprocket; Obtaining the maximum continuous rail pressure drop corresponding to each cylinder based on all rack-rail pressure difference values ​​corresponding to each cylinder includes: respectively determining whether all the rack-rail pressure differential values ​​corresponding to each cylinder are positive; If yes, then all the rack-rail pressure difference values ​​are accumulated to obtain the corresponding maximum continuous rail pressure drop; If not, the rack rail pressure difference values ​​that are consecutively positive among all the rack rail pressure difference values ​​are accumulated to obtain multiple rack rail pressure difference accumulated values, and the maximum value among the multiple rack rail pressure difference accumulated values ​​is determined as the corresponding maximum continuous rail pressure drop.

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