A method and device for processing misfire diagnosis

Abstract

The present application discloses a method and device for processing misfire diagnosis, the method comprising: obtaining the wheel speed change rate and misfire signal of the target vehicle; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle; then comparing the wheel speed change rate and the wheel speed change rate threshold, and comparing the misfire signal and the misfire signal threshold; when the wheel speed change rate exceeds the wheel speed change rate threshold, and the misfire signal exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road and the misfire diagnosis is shielded; wherein the misfire signal threshold is obtained by looking up a table based on the current speed and torque. When the vehicle is traveling on a bad road, the misfire diagnosis needs to be shielded. The method provided in the embodiment of the present application determines whether the vehicle is traveling on a bad road by comparing whether the wheel speed change rate and the misfire signal exceed the corresponding threshold, thereby determining whether the misfire diagnosis needs to be shielded, thereby improving the accuracy of processing the misfire diagnosis.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle diagnosis, and in particular to a method and device for processing misfire diagnosis. Background Art

[0002] Vehicle misfire diagnosis has always been an issue that needs to be focused on in vehicle driving safety. Misfire refers to an abnormal combustion phenomenon when the engine is running, which is caused by poor ignition energy, poor combustion quality, no combustion or incomplete combustion due to poor combustible gas mixture matching, engine mechanical reasons, ignition system failures, etc.

[0003] According to regulatory requirements, when a vehicle is traveling on a bad road, the misfire diagnosis needs to be shielded. In the prior art, when determining whether a vehicle is traveling on a bad road, the vehicle's wheel speed change rate is used alone. When the vehicle's wheel speed change rate is relatively large, the vehicle is determined to be traveling on a bad road and the misfire diagnosis needs to be shielded. However, if the vehicle is only determined to be traveling on a normal road, it is very likely that the vehicle will be misjudged as traveling on a bad road, resulting in the misjudgment of shielding the misfire diagnosis. Summary of the invention

[0004] The embodiments of the present application provide a method and apparatus for processing misfire diagnosis, so as to improve the accuracy of processing misfire diagnosis.

[0005] In a first aspect, an embodiment of the present application provides a method for processing misfire diagnosis, the method comprising:

[0006] Obtaining a wheel speed change rate and a misfire signal of the vehicle; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle;

[0007] The wheel speed change rate is compared with the wheel speed change rate threshold, and the misfire signal is compared with the misfire signal threshold; when the wheel speed change rate exceeds the wheel speed change rate threshold, and the misfire signal exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road, and the misfire diagnosis is shielded.

[0008] The misfire signal threshold is obtained by looking up a table based on the current rotation speed and torque.

[0009] In some possible implementations, the misfire signal includes:

[0010] Misfire signal before unlearned tooth deviation.

[0011] In some possible implementations, the misfire signal includes:

[0012] Misfire signal after learning tooth deviation.

[0013] In some possible implementations, the misfire signal includes:

[0014] The misfire signal is filtered after learning the tooth deviation.

[0015] In some possible implementations, obtaining a fire signal of a vehicle includes:

[0016] Acquire a misfire signal of the vehicle before learning the gear deviation, a misfire signal after learning the gear deviation, and a misfire signal after learning the gear deviation and after filtering;

[0017] When the wheel speed change rate exceeds the wheel speed change rate threshold and the misfire signal exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road, and shielding the misfire diagnosis includes:

[0018] When the wheel speed change rate exceeds the wheel speed change rate threshold, and at least one of the misfire signal before the unlearned tooth deviation, the misfire signal after the learned tooth deviation, and the misfire signal after the learned tooth deviation and filtered exceeds the corresponding misfire signal threshold, it is determined that the vehicle is traveling on a bad road and the misfire diagnosis is shielded.

[0019] In some possible implementations, the method further includes:

[0020] After the vehicle is driven from a bad road to a normal road, the misfire diagnosis is performed again after a preset delay.

[0021] In a second aspect, an embodiment of the present application provides a device for processing misfire diagnosis, the device comprising an acquisition module, a comparison module and a processing module:

[0022] An acquisition module is used to: acquire a wheel speed change rate and a misfire signal of the vehicle; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle;

[0023] a comparison module, used to compare the wheel speed change rate and the wheel speed change rate threshold, and to compare the misfire signal and the misfire signal threshold; the misfire signal threshold is a processing module obtained by looking up a table based on the current speed and torque, and is used to determine that the vehicle is traveling on a bad road and shield the misfire diagnosis when the wheel speed change rate exceeds the wheel speed change rate threshold and the misfire signal exceeds the misfire signal threshold.

[0024] In a third aspect, an embodiment of the present application further provides a device for processing misfire diagnosis, the device comprising a processor and a memory:

[0025] The memory is used to store relevant program codes;

[0026] The processor is used to call the program code to execute the method for processing misfire diagnosis described in any one of the embodiments of the first aspect above.

[0027] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method for processing misfire diagnosis described in any one of the embodiments of the first aspect above.

[0028] In the above implementation of the embodiment of the present application, the wheel speed change rate and the misfire signal of the target vehicle are first obtained; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle; then the wheel speed change rate and the wheel speed change rate threshold are compared, and the misfire signal and the misfire signal threshold are compared. When the wheel speed change rate exceeds the wheel speed change rate threshold and the misfire signal exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road and the misfire diagnosis is shielded; wherein the misfire signal threshold is obtained by looking up the table based on the current speed and torque. When the vehicle is traveling on a bad road, the misfire diagnosis needs to be shielded, and the misfire diagnosis is performed when the vehicle is traveling on a normal road. The method provided in the embodiment of the present application determines whether the vehicle is traveling on a bad road by comparing whether the wheel speed change rate and the misfire signal exceed the corresponding threshold, thereby determining whether the misfire diagnosis needs to be shielded, thereby improving the accuracy of processing the misfire diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. It is obvious that the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0030] Figure 1 This is a flow chart of a method for processing misfire diagnosis in an embodiment of the present application;

[0031] Figure 2 This is a flow chart of another method for processing misfire diagnosis in an embodiment of the present application;

[0032] Figure 3 This is a flow chart of another method for processing misfire diagnosis in an embodiment of the present application;

[0033] Figure 4 This is a flow chart of another method for processing misfire diagnosis in an embodiment of the present application;

[0034] Figure 5 This is a structural diagram of a device for processing misfire diagnosis in an embodiment of the present application;

[0035] Figure 6 FIG. 4 is a structural diagram of another device for processing misfire diagnosis in an embodiment of the present application. DETAILED DESCRIPTION

[0036] When the vehicle is traveling on a bad road, the misfire diagnosis needs to be shielded. In the prior art, when judging whether the vehicle is traveling on a bad road, the vehicle's wheel speed change rate is used alone to judge. When the vehicle's wheel speed change rate is relatively large, it is judged that the vehicle is traveling on a bad road and the misfire diagnosis needs to be shielded. However, if the vehicle is only judged based on the wheel speed change rate, it is very likely that the vehicle is misjudged as traveling on a bad road when it is traveling on a normal road, resulting in the misjudgment of shielding the misfire diagnosis.

[0037] Based on this, the embodiment of the present application provides a method for processing misfire diagnosis to improve the accuracy of misfire diagnosis. In specific implementation, the wheel speed change rate and the misfire signal of the target vehicle are first obtained; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle; then the wheel speed change rate and the wheel speed change rate threshold are compared, and the misfire signal and the misfire signal threshold are compared; when the wheel speed change rate exceeds the wheel speed change rate threshold, and the misfire signal exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road and the misfire diagnosis is shielded; wherein the misfire signal threshold is obtained by looking up the table based on the current speed and torque. When the vehicle is traveling on a bad road, the misfire diagnosis needs to be shielded, and the misfire diagnosis is performed when the vehicle is traveling on a normal road. The method provided in the embodiment of the present application determines whether the vehicle is traveling on a bad road by comparing whether the wheel speed change rate and the misfire signal exceed the corresponding threshold, thereby determining whether the misfire diagnosis needs to be shielded, thereby improving the accuracy of processing misfire diagnosis.

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. The described embodiments are only exemplary implementation methods of the present application, not all implementation methods. Those skilled in the art can combine the embodiments of the present application to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present application.

[0039] See also Figure 1 , shows a flow chart of a method for processing misfire diagnosis, the method specifically comprising the following steps:

[0040] S101: Acquire a wheel speed change rate and a misfire signal of the vehicle; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle;

[0041] First, the current vehicle's wheel speed change rate and misfire signal are obtained. The vehicle's wheel speed change rate refers to the change in wheel speed per unit time, and the wheel speed can be measured by the wheel speed sensor. The vehicle's current misfire signal is calculated based on the segmented interval, which refers to the time required for the crankshaft to rotate half a circle.

[0042] S102: comparing the wheel speed change rate with a wheel speed change rate threshold, and comparing the misfire signal with a misfire signal threshold;

[0043] The threshold of the misfire signal is determined by the current speed and torque of the vehicle. At different speeds and torques, the threshold of the corresponding misfire signal is different. Similarly, at different speeds and vehicle speeds, the threshold corresponding to the wheel speed change rate is also different.

[0044] S103: When the wheel speed change rate exceeds the wheel speed change rate threshold, and the misfire signal exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road, and misfire diagnosis is shielded.

[0045] If the current wheel speed change rate of the vehicle exceeds the wheel speed change rate threshold, and the current misfire signal exceeds the misfire signal threshold, then it can be determined that the vehicle is driving on a bad road and the misfire diagnosis needs to be shielded. If either of the above two conditions is not met, it can be determined that the vehicle is driving on a normal road and the misfire diagnosis is performed normally.

[0046] There are three types of vehicle misfire signals: the misfire signal before the gear deviation is learned, the misfire signal after the gear deviation is learned, and the misfire signal after the gear deviation is learned and filtered. When obtaining the vehicle's misfire signal, all three types of misfire signals must be obtained and detected. However, when judging whether the vehicle is driving on a bad road, as long as any of the three types of misfire signals is detected to exceed the corresponding misfire signal threshold, and the vehicle's wheel speed change rate exceeds the wheel speed change rate threshold, it can be determined that the vehicle is driving on a bad road. See Figure 2 As shown, a flow chart of a method for processing misfire diagnosis is shown, and the method specifically includes the following steps:

[0047] S201: Acquire the wheel speed change rate and misfire signal of the vehicle;

[0048] The misfire signal includes: the misfire signal dlutsk before learning the tooth deviation, the misfire signal lutsk after learning the tooth deviation, and the misfire signal flutsk after learning the tooth deviation and filtering. The current misfire signal of the vehicle is calculated based on the segmented interval, and the segmented interval refers to the time required for the crankshaft to rotate half a circle. When obtaining the misfire signal of the vehicle, three types of misfire signals are obtained.

[0049] Tooth deviation refers to the manufacturing tolerance of learning crankshaft. Generally, the gear of crankshaft contains 60 teeth. After the crankshaft rotates one circle, if 30 teeth and the other 30 teeth rotate at different angles, then there is tooth deviation. You can use 30 teeth as the reference and learn the other 30 teeth. Whether to learn tooth deviation can be set by the speed and torque of the vehicle. The tooth deviation is learned only when the speed and torque meet certain conditions.

[0050] S202: comparing the wheel speed change rate with a wheel speed change rate threshold, and comparing the misfire signal with a misfire signal threshold;

[0051] The threshold of the misfire signal is determined by the current speed and torque of the vehicle. At different speeds and torques, the corresponding thresholds of the misfire signal are different, and the thresholds corresponding to the three types of misfire signals are also different. It is necessary to compare different types of misfire signals and their corresponding misfire signal thresholds. Similarly, at different speeds and vehicle speeds, the thresholds of the wheel speed change rate are also different.

[0052] S203: When the wheel speed change rate exceeds the wheel speed change rate threshold, and at least one of the misfire signals exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road, and misfire diagnosis is shielded.

[0053] Since three types of misfire signals are obtained, including the misfire signal dlutsk before learning the tooth deviation, the misfire signal lutsk after learning the tooth deviation, and the misfire signal flutsk after learning the tooth deviation and filtering, when at least one of the three misfire signals exceeds the corresponding misfire signal threshold, and the current wheel speed change rate of the vehicle exceeds the wheel speed change rate threshold, it can be determined that the vehicle is driving on a bad road, and the misfire diagnosis needs to be shielded. When either of the above two conditions is not met, it can be determined that the vehicle is driving on a normal road and the misfire diagnosis is performed normally.

[0054] In addition, if the vehicle is driven back to a normal road from a bad road, it is necessary to extend a certain period of time before re-diagnosing the misfire. This is because the misfire signal or wheel speed change rate may not have returned to the normal range because the vehicle has just returned to the normal road, so it is necessary to extend the period of time before re-diagnosing the misfire.

[0055] In other embodiments of the present application, there are different processing methods for when to obtain the wheel speed change rate and the misfire signal of the vehicle, see Figure 3 , shows a flow chart of a method for processing misfire diagnosis, the method specifically comprising the following steps:

[0056] S301: Obtaining the wheel speed change rate of the vehicle;

[0057] S302: Compare the wheel speed change rate with a wheel speed change rate threshold;

[0058] S303: When the wheel speed change rate exceeds the wheel speed change rate threshold, obtaining a vehicle misfire signal;

[0059] The misfire signal includes: a misfire signal before the tooth deviation is learned, a misfire signal after the tooth deviation is learned, and a misfire signal after the tooth deviation is learned and filtered.

[0060] If it is determined that the vehicle is traveling on a bad road, it is necessary to simultaneously meet the conditions that the wheel speed change rate exceeds the wheel speed change rate threshold, and at least one of the three types of misfire signals exceeds the corresponding misfire signal threshold. Therefore, when obtaining the wheel speed change rate and misfire signal of the vehicle, the wheel speed change rate of the vehicle can be obtained first, and then the wheel speed change rate of the vehicle and the wheel speed change rate threshold are compared. If the current wheel speed change rate of the vehicle is less than the wheel speed change rate threshold, then the condition that the vehicle is traveling on a bad road is definitely not met. At this time, preferably, the misfire signal of the vehicle can be not obtained, and the misfire signal and the misfire signal threshold do not need to be compared, thereby reducing some unnecessary processes. When the wheel speed change rate of the vehicle exceeds the wheel speed change rate threshold, the misfire signal of the vehicle continues to be obtained, and three types of misfire signals are obtained at the same time.

[0061] S304: Compare the misfire signal with a misfire signal threshold;

[0062] S305: When at least one of the misfire signals exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road, and misfire diagnosis is shielded.

[0063] Since the wheel speed change rate of the vehicle has exceeded the wheel speed change rate threshold, when comparing the misfire signal and the misfire signal threshold, as long as there is a misfire signal that exceeds the corresponding misfire signal threshold, it can be determined that the vehicle is driving on a bad road and the misfire diagnosis needs to be shielded. In other words, if the three misfire signals are all less than the corresponding thresholds, then the vehicle is not driving on a bad road, but on a normal road surface, and the misfire diagnosis is performed normally.

[0064] Based on the same principle, the vehicle's misfire signal can also be obtained first, and the misfire signal and the misfire signal threshold can be compared. When at least one of the three misfire signals exceeds the corresponding misfire signal threshold, the vehicle's wheel speed change rate can be obtained. When the three misfire signals are all less than the corresponding misfire signal threshold, it can be known that the vehicle does not meet the condition of driving on a bad road, so the vehicle's wheel speed change rate can no longer be obtained. The implementation principle of this method is the same as the principle of the method described in the previous embodiment, so it will not be repeated here. For the flowchart of this method, see Figure 4 , specifically including the following steps:

[0065] S401: Acquire a fire signal of the vehicle;

[0066] S402: Compare the misfire signal with a misfire signal threshold;

[0067] S403: When at least one of the misfire signals exceeds the misfire signal threshold, obtaining a wheel speed change rate of the vehicle;

[0068] S404: comparing the wheel speed change rate with a wheel speed change rate threshold;

[0069] S405: When the wheel speed change rate exceeds the wheel speed change rate threshold, it is determined that the vehicle is traveling on a bad road, and the misfire diagnosis is shielded.

[0070] It should be noted that the time sequence of obtaining the vehicle's wheel speed change rate and obtaining the fire signal does not affect the implementation of the embodiment of the present application, and the vehicle's wheel speed change rate and the fire signal may also be obtained at the same time.

[0071] When obtaining three types of misfire signals of a vehicle, the three types of misfire signals can be obtained simultaneously through one process. The misfire signal threshold is calculated based on the current speed and torque of the vehicle, so when comparing the misfire signal and the misfire signal threshold, the threshold of one of the misfire signals can be calculated first, and then the misfire signal and the corresponding misfire signal threshold can be compared. When the misfire signal exceeds the misfire signal threshold, it is not necessary to compare the other two misfire signals with the corresponding misfire signal thresholds, thereby reducing the calculation process. However, if the misfire signal selected for judgment at first is less than the corresponding misfire signal threshold, the other two misfire signals and the corresponding misfire signal thresholds must be compared. When the three misfire signals are all less than the corresponding misfire signal thresholds, the vehicle does not meet the condition of driving on a bad road, and the misfire diagnosis is performed normally.

[0072] It should be noted that the above-mentioned method of obtaining the misfire signal and comparing the misfire signal with the misfire signal threshold is only an exemplary implementation method, and does not impose any form of limitation on the present application, nor does it affect the implementation of the embodiments of the present application.

[0073] In addition, the present application embodiment provides a device for processing misfire diagnosis, see Figure 5 , Figure 5 The schematic diagram of the structure of the device is shown. The device 500 includes an acquisition module 501, a comparison module 502 and a processing module 503:

[0074] An acquisition module 501 is used to: acquire a wheel speed change rate and a misfire signal of the vehicle; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle;

[0075] A comparison module 502 is used to compare the wheel speed change rate with the wheel speed change rate threshold, and compare the misfire signal with the misfire signal threshold; the misfire signal threshold is obtained by looking up a table based on the current speed and torque;

[0076] The processing module 503 is used to: when the wheel speed change rate exceeds the wheel speed change rate threshold and the misfire signal exceeds the misfire signal threshold, determine that the vehicle is traveling on a bad road and shield the misfire diagnosis.

[0077] The present application also provides a device for processing misfire diagnosis, see Figure 6 , Figure 6 The schematic diagram of the structure of the device is shown, and the device 600 includes a processor 601 and a memory 602:

[0078] The memory 602 is used to store relevant program codes;

[0079] The processor 601 is used to call the program code to execute the method for processing misfire diagnosis described in the above method embodiment.

[0080] In addition, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method for processing misfire diagnosis described in the above method embodiment.

[0081] Each embodiment in this specification focuses on the differences from other embodiments, and similar parts between the embodiments can refer to each other. Especially for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, in which the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network units, and some or all of the modules may be selected according to actual needs to implement the solution of the embodiment of the present application.

[0082] The above is only an exemplary embodiment of the present application and does not limit the present application in any form. Any equivalent changes or modifications made to the above embodiments are within the protection scope of the present application.

Claims

1. A method for processing misfire diagnosis, It is characterized in that The method comprises: Obtaining a wheel speed change rate and a misfire signal of the vehicle; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle; comparing the wheel speed change rate with the wheel speed change rate threshold, and comparing the misfire signal with the misfire signal threshold; when the wheel speed change rate exceeds the wheel speed change rate threshold, and the misfire signal exceeds the misfire signal threshold, determining that the vehicle is traveling on a bad road, and shielding the misfire diagnosis; The misfire signal threshold is obtained by looking up the table based on the current rotation speed and torque. Under different rotation speeds and vehicle speeds, the threshold corresponding to the wheel speed change rate is different.

2. The method according to claim 1, It is characterized in that The misfire signal includes: Misfire signal before unlearned tooth deviation.

3. The method according to claim 1, It is characterized in that The misfire signal includes: Misfire signal after learning tooth deviation.

4. The method according to claim 1, It is characterized in that The misfire signal includes: The misfire signal is filtered after learning the tooth deviation.

5. The method according to claim 1, It is characterized in that The obtaining of the fire signal of the vehicle comprises: Acquire a misfire signal of the vehicle before learning the gear deviation, a misfire signal after learning the gear deviation, and a misfire signal after learning the gear deviation and after filtering; When the wheel speed change rate exceeds the wheel speed change rate threshold and the misfire signal exceeds the misfire signal threshold, it is determined that the vehicle is traveling on a bad road, and shielding the misfire diagnosis includes: When the wheel speed change rate exceeds the wheel speed change rate threshold, and at least one of the misfire signal before the unlearned tooth deviation, the misfire signal after the learned tooth deviation, and the misfire signal after the learned tooth deviation and filtered exceeds the corresponding misfire signal threshold, it is determined that the vehicle is traveling on a bad road and the misfire diagnosis is shielded.

6. The method according to claim 1, It is characterized in that The method further comprises: After the vehicle is driven from a bad road to a normal road, the misfire diagnosis is performed again after a preset delay.

7. A device for processing misfire diagnosis, It is characterized in that The device comprises an acquisition module, a comparison module and a processing module: An acquisition module is used to: acquire a wheel speed change rate and a misfire signal of the vehicle; the misfire signal is calculated based on the time required for the crankshaft to rotate half a circle; a comparison module, for comparing the wheel speed change rate with the wheel speed change rate threshold, and comparing the misfire signal with the misfire signal threshold; the misfire signal threshold is obtained by looking up a table based on the current rotation speed and torque, and the threshold corresponding to the wheel speed change rate is different at different rotation speeds and vehicle speeds; The processing module is used to: when the wheel speed change rate exceeds the wheel speed change rate threshold and the misfire signal exceeds the misfire signal threshold, determine that the vehicle is traveling on a bad road and shield the misfire diagnosis.

8. A device for processing misfire diagnosis, It is characterized in that The device comprises a processor and a memory: The memory is used to store relevant program codes; The processor is used to call the program code to execute the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, It is characterized in that The computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method according to any one of claims 1 to 6.

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