A method and device for diagnosing an aging state of a front oxygen sensor

Abstract

The application discloses a front oxygen sensor aging state diagnosis method and device, relates to the technical field of vehicle sensor diagnosis, and collects crankshaft angle, camshaft angle and injection phase matched with the engine in real time, acquires the injection phase and rotating speed in the injection action process of the fuel injector and a plurality of Nernst voltage maximum values within a preset number of periods if the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, calculates the first average period required by a preset number of injection actions according to the injection phase and the rotating speed, calculates the second average period according to the plurality of Nernst voltage maximum values within the preset number of periods, and performs front oxygen sensor aging state diagnosis according to the first average period, the second average period and a preset threshold value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle sensor diagnosis, in particular to a front oxygen sensor aging state diagnosis method and device. BACKGROUND

[0002] When the engine is running in idle condition, the fuel injection amount of the injection system increases, and part of the fuel cannot be fully combusted and is discharged into the exhaust pipe. The unburned fuel in the exhaust pipe continues to burn in the exhaust pipe, generating carbon particles that adhere to the surface of the front oxygen sensor, causing the protective layer to peel off. The front oxygen sensor will also accelerate aging due to the high surface temperature, causing abnormal detection of the air-fuel ratio. Therefore, it is necessary to diagnose the aging state of the front oxygen sensor.

[0003] The existing diagnosis method for the aging state of the front oxygen sensor is to perform overall detection when the remaining actuators of the engine fail. During the overall detection, it is impossible to determine whether the front oxygen sensor has a problem in real time.

[0004] Therefore, how to detect whether the front oxygen sensor has an aging state in real time is a problem to be solved by the present application. SUMMARY

[0005] Therefore, the present application discloses a front oxygen sensor aging state diagnosis method and device, which aims to determine the engine injection state by combining the engine injection phase and the engine speed, so as to analyze the excess air coefficient fluctuation detected by the front oxygen sensor in theory, and effectively and timely detect whether the front oxygen sensor has an aging state.

[0006] In order to achieve the above-mentioned purpose, the disclosed technical solution is as follows:

[0007] The first aspect of the present application discloses a front oxygen sensor aging state diagnosis method, which comprises:

[0008] Real-time acquisition of the crankshaft angle, camshaft angle and injection phase matched with the engine;

[0009] If the crankshaft angle, camshaft angle and injection phase meet the synchronization condition, the injection phase and speed during the injection action of the injector are obtained, and a plurality of Nernst voltage maximum values within a predetermined number of periods are obtained;

[0010] According to the injection phase and the speed, a first average period required for a predetermined number of injection actions is calculated;

[0011] According to the plurality of Nernst voltage maximum values within the predetermined number of periods, a second average period is calculated;

[0012] According to the first average period, the second average period and a preset threshold, a pre-oxygen sensor aging state diagnosis is performed.

[0013] Preferably, when the crankshaft angle, the camshaft angle and the injection phase are synchronous, the injection phase and the rotation speed during the injection action of the fuel injector are obtained, and a plurality of Nernst voltage maximum values within a preset number of periods are continuously collected.

[0014] The crankshaft angle and the camshaft angle are compared with the injection phase respectively.

[0015] When the crankshaft angle is consistent with the injection phase, and the camshaft angle is consistent with the injection phase, it is determined that the crankshaft angle, the camshaft angle and the injection phase are synchronous.

[0016] Under the condition that the crankshaft angle, the camshaft angle and the injection phase are synchronous, the fuel injector performs the injection action to obtain the injection phase and the rotation speed during the injection action of the fuel injector, and a plurality of Nernst voltage maximum values within a preset number of periods are continuously collected.

[0017] Preferably, it further comprises:

[0018] When the crankshaft angle is not consistent with the injection phase, or the camshaft angle is not consistent with the injection phase, it is determined that the crankshaft angle, the camshaft angle and the injection phase are not synchronous.

[0019] Under the condition that the crankshaft angle, the camshaft angle and the injection phase are not synchronous, the crankshaft angle and the camshaft angle of the engine are continuously collected and matched with the injection phase until the crankshaft angle and the camshaft angle are consistent with the injection phase.

[0020] Preferably, according to the injection phase and the rotation speed, a first average period required for a preset number of injection actions is calculated, which comprises:

[0021] According to the injection phase, the corresponding number of teeth of the crankshaft or the camshaft required for a preset number of injection actions is counted.

[0022] According to the rotation speed, the corresponding time of a single tooth is converted.

[0023] The corresponding time of a single tooth is multiplied by the corresponding number of teeth to obtain the first average period required for a preset number of injection actions.

[0024] Preferably, according to the plurality of Nernst voltage maximum values within a preset number of periods, a second average period is calculated, which comprises:

[0025] The multiple Nernst voltage maximum values collected continuously in the preset number of periods are averaged to obtain a second average period.

[0026] Preferably, the front oxygen sensor aging state diagnosis according to the first average period, the second average period and a preset threshold value comprises:

[0027] The first average period and the second average period are calculated to obtain a difference value.

[0028] The front oxygen sensor aging state diagnosis is performed according to the difference value and a preset threshold value.

[0029] In the process of performing the front oxygen sensor aging state diagnosis, if the difference value is less than or equal to the preset threshold value, it is determined that the front oxygen sensor has no aging phenomenon.

[0030] If the difference value is greater than the preset threshold value, it is determined that the front oxygen sensor has an aging phenomenon.

[0031] The second aspect of the application discloses a front oxygen sensor aging state diagnosis device, the device comprises:

[0032] A real-time acquisition unit is configured to acquire the crankshaft angle, the camshaft angle and the injection phase matched with the engine in real time.

[0033] An acquisition unit is configured to acquire the injection phase and the rotation speed in the process of executing the injection action of the fuel injector and multiple Nernst voltage maximum values in a preset number of periods if the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition.

[0034] A first calculation unit is configured to calculate a first average period required for a preset number of injection action executions according to the injection phase and the rotation speed.

[0035] A second calculation unit is configured to calculate a second average period according to the multiple Nernst voltage maximum values in the preset number of periods.

[0036] A diagnosis unit is configured to perform the front oxygen sensor aging state diagnosis according to the first average period, the second average period and a preset threshold value.

[0037] Preferably, the acquisition unit comprises:

[0038] A comparison module is configured to compare the crankshaft angle and the camshaft angle with the injection phase, respectively.

[0039] A first determination module is configured to determine that the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition when the crankshaft angle is consistent with the injection phase and the camshaft angle is consistent with the injection phase.

[0040] The acquisition module is configured to, under the condition that the crankshaft angle, the camshaft angle and the injection phase are synchronized, execute an injection action by the fuel injector to acquire an injection phase and a rotation speed during execution of the injection action by the fuel injector and a plurality of Nernst voltage maximum values continuously collected within a preset number of periods.

[0041] Preferably, the method further comprises:

[0042] The determination unit is configured to determine that the crankshaft angle, the camshaft angle and the injection phase are not synchronized when the crankshaft angle is inconsistent with the injection phase or the camshaft angle is inconsistent with the injection phase.

[0043] The collection unit is configured to, under the condition that the crankshaft angle, the camshaft angle and the injection phase are not synchronized, continue to collect the crankshaft angle and the camshaft angle of the engine and match the injection phase until the crankshaft angle and the camshaft angle are consistent with the injection phase.

[0044] Preferably, the first calculation unit comprises:

[0045] The statistical module is configured to statistically acquire a corresponding number of teeth of the crankshaft or the camshaft required for execution of a preset number of injection actions according to the injection phase.

[0046] The conversion module is configured to convert the rotation speed into a corresponding time of a single tooth.

[0047] The first calculation module is configured to multiply the corresponding time of the single tooth by the corresponding number of teeth to obtain a first average period required for execution of the preset number of injection actions.

[0048] According to the technical solution, the application discloses a front oxygen sensor aging state diagnosis method and device, relates to the technical field of vehicle sensor diagnosis, and acquires a crankshaft angle, a camshaft angle and an injection phase matched with an engine in real time. If the crankshaft angle, the camshaft angle and the injection phase are synchronized, an injection phase and a rotation speed during execution of an injection action by a fuel injector are acquired, a plurality of Nernst voltage maximum values within a preset number of periods are acquired, a first average period required for execution of a preset number of injection actions is calculated according to the injection phase and the rotation speed, a second average period is calculated according to the plurality of Nernst voltage maximum values within the preset number of periods, and a front oxygen sensor aging state diagnosis is performed according to the first average period, the second average period and a preset threshold.

[0049] By the above scheme, the engine fuel injection state is judged in combination with the engine fuel injection phase and the engine speed, so as to analyze the excess air coefficient fluctuation condition detected by the front oxygen sensor in theory, and then judge whether the front oxygen sensor is aged according to the first average period, the second average period and the preset threshold value, so that whether the front oxygen sensor is in an aging state can be effectively and timely detected. In addition, the control logic of the electronic control system is ensured, so that the air-fuel ratio is always maintained near the set value, so that the fuel can be fully burned, and the exhaust emission is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute a part of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0051] Figure 1 A flowchart of a front oxygen sensor aging state diagnosis method disclosed by an embodiment of the present application;

[0052] Figure 2 A flowchart of another front oxygen sensor aging state diagnosis method disclosed by an embodiment of the present application;

[0053] Figure 3 A structural diagram of a front oxygen sensor aging state diagnosis device disclosed by an embodiment of the present application;

[0054] Figure 4 A structural diagram of an electronic device disclosed by an embodiment of the present application. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0056] In the present application, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the statement "comprising a" does not exclude the presence of another identical element in the process, method, article or device comprising the element.

[0057] From the background, the existing diagnosis method of the aging state of the front oxygen sensor is to detect the whole engine when the remaining actuators of the engine fail. In the process of overall detection, it is determined whether the front oxygen sensor has a problem through experience, and the aging state of the front oxygen sensor cannot be detected in real time. Therefore, how to detect the aging state of the front oxygen sensor in real time is a problem to be solved by the present application.

[0058] In order to solve the above problems, the present application discloses a front oxygen sensor aging state diagnosis method and device, which collects the crankshaft angle, camshaft angle and injection phase matched with the engine in real time. If the crankshaft angle, camshaft angle and injection phase meet the synchronization condition, the injection phase and speed during the injection action of the fuel injector are obtained, and a plurality of Nernst voltage maximum values within a preset number of periods are obtained. According to the injection phase and speed, the first average period required for a preset number of injection actions is calculated. According to the plurality of Nernst voltage maximum values within the preset number of periods, the second average period is calculated. According to the first average period, the second average period and the preset threshold, the front oxygen sensor aging state diagnosis is performed. Through the above scheme, the engine injection state is judged by combining the engine injection phase and engine speed, so as to analyze the excess air coefficient fluctuation detected by the front oxygen sensor position in theory, and then judge whether the front oxygen sensor is aging according to the first average period, the second average period and the preset threshold. The aging state of the front oxygen sensor can be effectively and timely detected. In addition, the control logic of the electronic control system is guaranteed, so that the air-fuel ratio is always maintained near the set value, so that the fuel can be fully burned, and the exhaust emission is reduced. The specific implementation mode is specifically described in the following embodiments.

[0059] Reference Figure 1 As shown in the figure, the front oxygen sensor aging state diagnosis method disclosed by the embodiment of the present application mainly includes the following steps:

[0060] S101: Collecting the crankshaft angle, camshaft angle and injection phase matched with the engine in real time.

[0061] The crankshaft angle of the engine can be collected in real time by the crankshaft position sensor. The crankshaft position sensor is a sensor for detecting the crankshaft angle and the piston top dead center of the engine. It is usually installed behind the crankshaft pulley or near the flywheel. Some sensors are installed on the cylinder block and driven by the crankshaft. The function of the crankshaft position sensor is to determine the position of the crankshaft, i.e. the crankshaft angle.

[0062] The camshaft angle of the engine can be collected in real time by a camshaft position sensor. The camshaft position sensor is a sensor for detecting the rotational position of the camshaft. The camshaft position sensor is a cylinder identification and positioning device that inputs the camshaft position signal as the main control signal for the cylinder ECU ignition control.

[0063] The injection phase matched by the engine can be collected in real time by a phase sensor.

[0064] S102: If the crankshaft angle, the camshaft angle, and the injection phase meet the synchronization condition, the injection phase and the rotation speed during the injection action of the injector are obtained, and a plurality of Nernst voltage maximum values within a preset number of periods are obtained.

[0065] The crankshaft angle, the camshaft angle, and the injection phase are compared, i.e., whether the crankshaft angle / camshaft angle is consistent with the phase angle of the injection action execution. When the crankshaft angle / camshaft angle is consistent with the phase angle of the injection phase, the injector or the jet begins to execute the injection action.

[0066] If the crankshaft / camshaft angle is not consistent with the injection phase, the injection phase continues to be collected and matched until the phase is consistent. When the phase is consistent, the system begins to detect the aging state of the front oxygen sensor.

[0067] The rotation speed represents the number of revolutions per minute of the engine.

[0068] Specifically, if the crankshaft angle, the camshaft angle, and the injection phase meet the synchronization condition, the injection phase and the rotation speed during the injection action of the injector are obtained, and a plurality of Nernst voltage maximum values within a preset number of periods are obtained, as shown in A1-A3.

[0069] A1: The crankshaft angle and the camshaft angle are compared with the injection phase, respectively.

[0070] A2: When the crankshaft angle is consistent with the injection phase, and the camshaft angle is consistent with the injection phase, it is determined that the crankshaft angle, the camshaft angle, and the injection phase meet the synchronization condition.

[0071] The aging system for detecting the aging state of the front oxygen sensor collects the crankshaft and camshaft phase angles at the beginning of the detection, and judges whether they are consistent with the phase angle of the injection action execution. If they remain consistent, it is considered that the injection action has been executed, and the aging state begins to be detected.

[0072] A3: Under the condition that the crankshaft angle, the camshaft angle, and the injection phase meet the synchronization condition, the injector executes the injection action to obtain the injection phase and the rotation speed during the injection action of the injector, and a plurality of Nernst voltage maximum values within a preset number of periods (such as a) are continuously collected.

[0073] Wherein, the value of a is an integer greater than or equal to 1.

[0074] After the fuel injector performs the injection action, the exhaust gas generated after a series of ignition combustion actions reaches the three-way catalytic system quickly, and the Nernst voltage signal is detected by the front oxygen sensor and fed back to the electronic control unit. In this regard, according to the fuel injection combustion characteristics of the internal combustion engine, the detected Nernst voltage change period should be consistent with the change period of the number of fuel injection cylinders of the internal combustion engine. However, the Nernst voltage fed back by the aging front oxygen sensor will show a phenomenon of slow response signal.

[0075] The front oxygen sensor is located behind the combustion chamber. The front oxygen sensor is usually used to detect the excess air coefficient of the burned gas, and then feed back to the electronic control unit to complete the closed-loop control, so that the air-fuel ratio is maintained near 14.7.

[0076] The Nernst voltage is a feedback electrical signal used by the oxygen sensor to detect the excess air coefficient, which is strongly related to the excess air coefficient.

[0077] During the operation of the front oxygen sensor, when the engine mixture concentration is controlled in a very narrow range centered on the theoretical air-fuel ratio 14.7, the fuel combustion is sufficient, and the carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx) emissions in the exhaust gas are low. When the engine is running in the idling condition, the fuel injection amount of the injection system increases, and part of the fuel cannot be fully burned and is discharged into the exhaust pipe. The unburned fuel continues to burn in the exhaust pipe, generating carbon particles, which adhere to the surface of the front oxygen sensor and cause the protective layer to peel off. The oxygen sensor will also accelerate the aging due to the high surface temperature, causing abnormal detection of the air-fuel ratio. In this regard, based on the fuel injection system characteristics of the electronic control unit, the application proposes a method for detecting the aging state of the front oxygen sensor.

[0078] When the crankshaft angle and the injection phase are inconsistent, or the camshaft angle and the injection phase are inconsistent, it is determined that the crankshaft angle, the camshaft angle and the injection phase do not meet the synchronization condition. Under the condition that the crankshaft angle, the camshaft angle and the injection phase do not meet the synchronization condition, the crankshaft angle and the camshaft angle of the engine are continuously collected and matched with the injection phase until the crankshaft angle and the camshaft angle are consistent with the injection phase.

[0079] S103: According to the injection phase and the speed, calculate the first average period required for a preset number of injection actions.

[0080] In S103, after performing the aging detection, the Nernst voltage value fed back by the front oxygen sensor is collected, and the maximum value of a preset number (a) of periods is continuously calculated to ensure that the detected Nernst voltage is indeed a period of a. Then, the average time of fluctuation of the Nernst voltage per period is calculated. At the same time, the average period time required for a injection operation is calculated, that is, the first average period, in combination with the injection phase and the current speed value.

[0081] Based on the characteristic phenomenon of the aging of the oxygen sensor, once the aging occurs, the change period of the Nernst voltage signal of the oxygen sensor will be delayed. In this regard, the execution time of the injection operation (which affects the change of the Nernst voltage) is compared with the actual response time of the Nernst voltage.

[0082] Specifically, according to the injection phase and the speed, the first average period required for a preset number of injection operations is calculated, as shown in B1-B3.

[0083] B1: According to the injection phase, the corresponding number of teeth of the crankshaft or camshaft required for a preset number of injection operations is counted.

[0084] B2: The corresponding time of a single tooth is converted according to the speed.

[0085] B3: The corresponding time of a single tooth is multiplied by the corresponding number of teeth to obtain the first average period required for a preset number of injection operations.

[0086] The preset number is set according to the actual situation, which is not limited in the present application.

[0087] S104: According to the maximum values of the Nernst voltage in a plurality of preset periods, the second average period is calculated.

[0088] In S104, the maximum values of the Nernst voltage in a plurality of preset periods collected continuously are averaged to obtain the second average period.

[0089] Regardless of whether the front oxygen sensor is aging or not, when the speed is stable, the response time of the Nernst voltage of the front oxygen sensor will show a nearly stable periodical change. The change period of the Nernst voltage, that is, the second average period, can be obtained according to the continuously changing high level position or other methods.

[0090] S105: According to the first average period, the second average period, and a preset threshold value, the aging state of the front oxygen sensor is diagnosed.

[0091] After the result (first average period, second average period) is calculated, comparison is made according to the first average period, the second average period and the preset threshold value. If the period difference meets the set threshold value, it is considered that the front oxygen sensor has no aging phenomenon; otherwise, there is an aging phenomenon.

[0092] The preset threshold value is set according to actual conditions, which is not limited in the present application.

[0093] According to the first average period, the second average period and the preset threshold value, the process of diagnosing the aging state of the front oxygen sensor is performed, as shown in C1-C4.

[0094] C1: The first average period and the second average period are calculated to obtain a difference value.

[0095] C2: According to the difference value and the preset threshold value, the aging state of the front oxygen sensor is diagnosed.

[0096] C3: In the process of diagnosing the aging state of the front oxygen sensor, if the difference value is less than or equal to the preset threshold value, it is determined that the front oxygen sensor has no aging phenomenon.

[0097] C4: If the difference value is greater than the preset threshold value, it is determined that the front oxygen sensor has an aging phenomenon.

[0098] It should be noted that each injection will have a process from dilution to enrichment and then to dilution for the exhaust aftertreatment system. For such a process, the Nernst voltage fed back by the front oxygen sensor should be a process from low to high and then to low. In this regard, if the exhaust has a circulation process and the Nernst voltage does not, it can be considered that the corresponding period is slow and there is an aging phenomenon.

[0099] If there is an aging phenomenon, it is recommended not to be included in the enterprise standard / specification.

[0100] In order to facilitate the understanding of a method for diagnosing the aging state of a front oxygen sensor, combined with the above method for diagnosing the aging state of a front oxygen sensor, an example is given as follows: Figure 2

[0101] Figure 2 Among them, the crank angle and the cam angle are collected;

[0102] It is judged whether the crank angle, the camshaft angle and the injection phase meet the synchronization condition;

[0103] If not, return to execute the step of collecting the crank angle and the cam angle;

[0104] If yes, the Nernst voltage value of the front oxygen sensor is collected, and the aging state of the front oxygen sensor is detected;

[0105] ​The average period of a injection action execution, that is, a first average period, is calculated according to the injection phase and the rotation speed;

[0106] The maximum Nernst voltage values of a number of continuous periods are collected, and a second average period is calculated;

[0107] The difference between the first average period and the second average period is calculated, and whether the difference meets a preset threshold is compared;

[0108] If yes, it is determined that the front oxygen sensor has no aging phenomenon;

[0109] If no, it is determined that the front oxygen sensor has an aging phenomenon.

[0110] The application can effectively detect the aging state of the front oxygen sensor, thereby guaranteeing the control logic of the electronic control system, keeping the air-fuel ratio around the set value, enabling the fuel to be fully combusted, and reducing exhaust emission. The key point of the application is to combine the engine injection phase. By judging the engine injection state, the fluctuation of the excess air coefficient detected by the front oxygen sensor in theory is analyzed, and then it is determined whether the front oxygen sensor has aging.

[0111] The application has the following beneficial effects: The engine injection state is judged by combining the engine injection phase and the engine rotation speed, the fluctuation of the excess air coefficient detected by the front oxygen sensor in theory is analyzed, and then it is determined whether the front oxygen sensor has aging according to the first average period, the second average period, and the preset threshold. The aging state of the front oxygen sensor can be effectively and timely detected. In addition, the control logic of the electronic control system is guaranteed, the air-fuel ratio is kept around the set value, the fuel can be fully combusted, and exhaust emission is reduced.

[0112] Based on the above embodiment Figure 1 A front oxygen sensor aging state diagnosis method is disclosed, and the application also discloses a front oxygen sensor aging state diagnosis device, as shown in the accompanying drawings. Figure 3 The front oxygen sensor aging state diagnosis device comprises:

[0113] A real-time acquisition unit 301 is configured to acquire the crankshaft angle, the camshaft angle, and the injection phase matched with the engine in real time.

[0114] An acquisition unit 302 is configured to acquire the injection phase and the rotation speed in the process of the injection action of the injector and a plurality of maximum Nernst voltage values in a preset number of periods if the crankshaft angle, the camshaft angle, and the injection phase meet the synchronization condition.

[0115] The first calculation unit 303 is configured to calculate a first average period required for a preset number of fuel injection actions according to the fuel injection phase and the rotation speed.

[0116] The second calculation unit 304 is configured to calculate a second average period according to a plurality of Nernst voltage maximum values in the preset number of periods.

[0117] The diagnosis unit 305 is configured to perform a front oxygen sensor aging state diagnosis according to the first average period, the second average period and a preset threshold value.

[0118] Further, the acquisition unit 302 comprises:

[0119] The comparison module is configured to compare the crankshaft angle and the camshaft angle with the injection phase respectively.

[0120] The first determination module is configured to determine that the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition when the crankshaft angle is consistent with the injection phase and the camshaft angle is consistent with the injection phase.

[0121] The acquisition module is configured to execute the injection action of the fuel injector under the synchronization condition of the crankshaft angle, the camshaft angle and the injection phase, to acquire the fuel injection phase and the rotation speed in the process of the injection action of the fuel injector and the plurality of Nernst voltage maximum values continuously collected in the preset number of periods.

[0122] Further, the front oxygen sensor aging state diagnosis device further comprises:

[0123] The determination unit is configured to determine that the crankshaft angle, the camshaft angle and the injection phase do not meet the synchronization condition when the crankshaft angle is inconsistent with the injection phase or the camshaft angle is inconsistent with the injection phase.

[0124] The acquisition unit is configured to continue to acquire the crankshaft angle and the camshaft angle of the engine and match the injection phase under the condition that the crankshaft angle, the camshaft angle and the injection phase do not meet the synchronization condition, until the crankshaft angle and the camshaft angle are consistent with the injection phase.

[0125] Further, the first calculation unit 303 comprises:

[0126] The statistical module is configured to count the corresponding number of teeth of the crankshaft or the camshaft required for the preset number of fuel injection actions according to the fuel injection phase.

[0127] The conversion module is configured to convert the rotation speed into the corresponding time of a single tooth.

[0128] The first calculation module is configured to multiply the corresponding time of a single tooth by the corresponding number of teeth to obtain the first average period required for the preset number of fuel injection actions.

[0129] Further, the second calculation unit 304 is specifically configured to average the plurality of Nernst voltages maximum values collected in the preset number of periods to obtain a second average period.

[0130] Further, the diagnostic unit 305 includes:

[0131] The second calculation module is configured to calculate the difference between the first average period and the second average period to obtain a difference value.

[0132] The diagnostic module is configured to diagnose the aging state of the front oxygen sensor according to the difference value and a preset threshold.

[0133] The second determination module is configured to determine that the front oxygen sensor has no aging phenomenon if the difference value is less than or equal to the preset threshold during the diagnosis of the aging state of the front oxygen sensor.

[0134] The third determination module is configured to determine that the front oxygen sensor has an aging phenomenon if the difference value is greater than the preset threshold.

[0135] The beneficial effects of the embodiments of the present application are as follows: the engine injection phase and the engine speed are combined to determine the engine injection state, so as to analyze the excess air coefficient fluctuation detected by the front oxygen sensor in theory, and then determine whether the front oxygen sensor has an aging phenomenon according to the first average period, the second average period and the preset threshold. The front oxygen sensor can be effectively and timely detected to determine whether the front oxygen sensor has an aging state. In addition, the control logic of the electronic control system is ensured, so that the air-fuel ratio is always maintained near the set value, so that the fuel can be fully burned, and the exhaust emission is reduced.

[0136] The embodiments of the present application also provide a storage medium including stored instructions, wherein the instructions, when executed, control a device where the storage medium is located to perform the front oxygen sensor aging state diagnosis method.

[0137] The embodiments of the present application also provide an electronic device, a structure diagram of which is shown in Figure 4 The electronic device specifically includes a memory 401 and one or more instructions 402, wherein the one or more instructions 402 are stored in the memory 401 and are configured to be executed by one or more processors 403 to execute the front oxygen sensor aging state diagnosis method.

[0138] For simple description, each of the foregoing method embodiments is described as a combination of a series of actions, but those skilled in the art shall understand that the present application is not limited to the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art shall understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0139] It should be noted that each of the embodiments in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same and similar parts between the embodiments can be referred to each other. For system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.

[0140] The steps in the method of each embodiment of the present application can be adjusted in sequence, combined and reduced according to actual needs.

[0141] Finally, it should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or sequence between the entities or operations.

[0142] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the scope of the present application. Therefore, the present application shall not be limited to the embodiments shown herein, but shall conform to the widest scope consistent with the principles and novel features disclosed herein.

[0143] The above is only the preferred embodiment of the present application. It should be noted that for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements shall be considered as the protection scope of the present application.

Claims

1. A method of diagnosing an aging state of a front oxygen sensor, characterized by, The method comprises: Real-time acquisition of crank angle, camshaft angle and injection phase matched with the engine; If the crank angle, camshaft angle and injection phase are consistent with the synchronization condition, the injection phase and rotation speed during the injection action of the injector are acquired, and a plurality of Nernst voltage maximum values within a preset number of cycles are acquired; According to the injection phase and the rotation speed, the first average cycle required for a preset number of injection actions is calculated; According to the plurality of Nernst voltage maximum values within the preset number of cycles, the change cycle of the Nernst voltage is obtained according to the continuously changing high level position, and the second average cycle is calculated; According to the first average cycle, the second average cycle and a preset threshold, the aging state of the front oxygen sensor is diagnosed.

2. The method of claim 1, wherein, If the crank angle, camshaft angle and injection phase are consistent with the synchronization condition, the injection phase and rotation speed during the injection action of the injector are acquired, and a plurality of Nernst voltage maximum values within a preset number of cycles are acquired, comprising: The crank angle and the camshaft angle are compared with the injection phase respectively; When the crank angle is consistent with the injection phase, and the camshaft angle is consistent with the injection phase, it is determined that the crank angle, the camshaft angle and the injection phase are consistent with the synchronization condition; Under the condition that the crank angle, the camshaft angle and the injection phase are consistent with the synchronization condition, the injector performs the injection action to acquire the injection phase and the rotation speed during the injection action of the injector and continuously acquire a plurality of Nernst voltage maximum values within a preset number of cycles.

3. The method of claim 2, wherein, Further comprising: When the crank angle is inconsistent with the injection phase, or the camshaft angle is inconsistent with the injection phase, it is determined that the crank angle, the camshaft angle and the injection phase are inconsistent with the synchronization condition; Under the condition that the crank angle, the camshaft angle and the injection phase are inconsistent with the synchronization condition, the crank angle and the camshaft angle of the engine are continuously acquired and matched with the injection phase until the crank angle and the camshaft angle are consistent with the injection phase.

4. The method of claim 1, wherein, According to the injection phase and the rotation speed, the first average cycle required for a preset number of injection actions is calculated, comprising: According to the injection phase, the corresponding number of teeth of the crank or the camshaft required for a preset number of injection actions is counted; According to the rotation speed, the corresponding time of a single tooth is converted; The corresponding time of a single tooth and the corresponding number of teeth are multiplied to obtain the first average cycle required for a preset number of injection actions.

5. The method of claim 1, wherein, According to the first average cycle, the second average cycle and a preset threshold, the aging state of the front oxygen sensor is diagnosed, comprising: The first average cycle and the second average cycle are subtracted to obtain a difference value; According to the difference value and the preset threshold, the aging state of the front oxygen sensor is diagnosed; During the process of diagnosing the aging state of the front oxygen sensor, if the difference value is less than or equal to the preset threshold, it is determined that the front oxygen sensor has no aging phenomenon; If the difference value is greater than the preset threshold, it is determined that the front oxygen sensor has an aging phenomenon.

6. A pre-oxygen sensor aging state diagnosis device characterized by comprising: The device comprises: The real-time acquisition unit is configured to acquire, in real time, a crankshaft angle, a camshaft angle and an injection phase matched with the engine; The acquisition unit is configured to acquire, if the crankshaft angle, the camshaft angle and the injection phase are consistent with the synchronization condition, an injection phase and a rotation speed during an injection action of the fuel injector, and a plurality of Nernst voltage maximum values in a preset number of periods; The first calculation unit is configured to calculate a first average period required for a preset number of injection actions according to the injection phase and the rotation speed; The second calculation unit is configured to calculate a second average period according to a change period of the Nernst voltage obtained according to a continuously changing high level position according to the plurality of Nernst voltage maximum values in the preset number of periods; The diagnosis unit is configured to perform a pre-oxygen sensor aging state diagnosis according to the first average period, the second average period and a preset threshold value.

7. The apparatus of claim 6, wherein, The acquisition unit comprises: The comparison module is configured to compare the crankshaft angle and the camshaft angle with the injection phase respectively; The first determination module is configured to determine that the crankshaft angle, the camshaft angle and the injection phase are consistent with the synchronization condition when the crankshaft angle is consistent with the injection phase and the camshaft angle is consistent with the injection phase; The acquisition module is configured to acquire, under the condition that the crankshaft angle, the camshaft angle and the injection phase are consistent with the synchronization condition, an injection phase and a rotation speed during an injection action of the fuel injector, and a plurality of Nernst voltage maximum values in a preset number of periods.

8. The apparatus of claim 7, wherein, Further comprising: The determination unit is configured to determine that the crankshaft angle, the camshaft angle and the injection phase are inconsistent with the synchronization condition when the crankshaft angle is inconsistent with the injection phase or the camshaft angle is inconsistent with the injection phase; The acquisition unit is configured to continue to acquire the crankshaft angle and the camshaft angle of the engine and match the injection phase until the crankshaft angle and the camshaft angle are consistent with the injection phase under the condition that the crankshaft angle, the camshaft angle and the injection phase are inconsistent with the synchronization condition.

9. The apparatus of claim 6, wherein, The first calculation unit comprises: The statistics module is configured to count a corresponding number of teeth of the crankshaft or the camshaft required for a preset number of injection actions according to the injection phase; The conversion module is configured to convert the rotation speed into a corresponding time of a single tooth; The first calculation module is configured to perform a product calculation on the corresponding time of the single tooth and the corresponding number of teeth to obtain a first average period required for a preset number of injection actions.

Images