Method and device for diagnosing aging state of front oxygen sensor

Abstract

The invention discloses a method and device for diagnosing the aging state of a front oxygen sensor, and relates to the technical field of vehicle sensor diagnos.The method comprises the steps that the crankshaft angle and the camshaft angle of an engine and the injection phase matched with the engine are collected in real time, and if the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, the engine is started; the method comprises the following steps: acquiring an oil injection phase and a rotating speed in the process that an oil injector executes an injection action, and a plurality of Nernst voltage maximum values in a preset number of periods, calculating a first average period required for executing the preset number of oil injection actions according to the oil injection phase and the rotating speed, and calculating a second average period required for executing the preset number of oil injection actions according to the plurality of Nernst voltage maximum values in the preset number of periods; calculating a second average period, and diagnosing the aging state of the front oxygen sensor 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, and more specifically, to a method and device for diagnosing the aging status of a front oxygen sensor. Background Art

[0002] When the engine is running at idle speed, the fuel injection volume of the injection system increases, and some fuel cannot be fully burned 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 and cause the protective layer to peel off. The front oxygen sensor will also accelerate aging due to excessive surface temperature, causing abnormal air-fuel ratio detection. Therefore, it is necessary to diagnose the aging status of the front oxygen sensor.

[0003] The existing method of diagnosing the aging status of the front oxygen sensor is to perform an overall detection when other actuators of the engine fail. During the overall detection process, it is judged based on experience whether there is a problem with the front oxygen sensor, and it is impossible to detect in real time whether the front oxygen sensor is in an aging state.

[0004] Therefore, how to detect in real time whether the front oxygen sensor is in an aging state is a problem that needs to be solved urgently in this application. Summary of the invention

[0005] In view of this, the present application discloses a method and device for diagnosing the aging status of a front oxygen sensor, which aims to determine the engine injection status by combining the engine injection phase and the engine speed, so as to analyze the fluctuation of the excess air coefficient detected at the theoretical front oxygen sensor position, and can effectively and real-time detect whether the front oxygen sensor is in an aging state.

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

[0007] In a first aspect, the present application discloses a method for diagnosing an aging state of a front oxygen sensor, the method comprising:

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

[0009] If the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, the injection phase and the rotation speed of the injector during the injection action, and multiple Nernst voltage maximum values ​​within a preset number of cycles are obtained;

[0010] Calculating a first average period required for executing a preset number of injection actions according to the injection phase and the rotation speed;

[0011] Calculating a second average period based on a plurality of Nernst voltage maximum values ​​within a preset number of periods;

[0012] The aging state of the front oxygen sensor is diagnosed according to the first averaging period, the second averaging period and a preset threshold.

[0013] Preferably, if the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, the injection phase and the speed of the injector during the injection action are obtained, as well as multiple Nernst voltage maximum values ​​within a preset number of cycles, including:

[0014] comparing the crankshaft angle and the camshaft angle 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, determining that the crankshaft angle, the camshaft angle, and the injection phase meet a synchronization condition;

[0016] When the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, the injector performs an injection action to obtain the injection phase and rotation speed during the injection action of the injector and continuously collect multiple Nernst voltage maximum values ​​within a preset number of cycles.

[0017] Preferably, it also includes:

[0018] When the crankshaft angle is inconsistent with the injection phase, or the camshaft angle is inconsistent with the injection phase, determining that the crankshaft angle, the camshaft angle, and the injection phase do not meet the synchronization condition;

[0019] When 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 continue to be collected and the injection phase is matched until the crankshaft angle and the camshaft angle are consistent with the injection phase.

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

[0021] A corresponding number of teeth of the crankshaft or camshaft required for executing a preset number of injection actions according to the injection phase statistics;

[0022] Convert the speed into the corresponding time of a single tooth;

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

[0024] Preferably, the step of calculating the second average period based on a plurality of Nernst voltage maximum values ​​within a preset number of periods includes:

[0025] The plurality of Nernst voltage maximum values ​​within a preset number of cycles continuously collected are averaged to obtain a second average cycle.

[0026] Preferably, the aging state diagnosis of the front oxygen sensor is performed according to the first averaging period, the second averaging period and a preset threshold, including:

[0027] Calculate the difference between the first average period and the second average period to obtain a difference value;

[0028] diagnosing the aging state of the front oxygen sensor according to the difference and a preset threshold;

[0029] During the process of diagnosing the aging state of the front oxygen sensor, if the difference is less than or equal to the preset threshold, it is determined that the front oxygen sensor has no aging phenomenon;

[0030] If the difference is greater than the preset threshold, it is determined that the front oxygen sensor is aged.

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

[0032] A real-time acquisition unit, used for real-time acquisition of the engine's crankshaft angle, camshaft angle, and injection phase matched by the engine;

[0033] an acquisition unit, configured to acquire the injection phase and rotation speed of the injector during the injection operation, and multiple Nernst voltage maximum values ​​within a preset number of cycles if the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition;

[0034] A first calculation unit, configured to calculate a first average period required for executing a preset number of injection actions according to the injection phase and the rotation speed;

[0035] A second calculation unit, used for calculating a second average period according to a plurality of Nernst voltage maximum values ​​within a preset number of periods;

[0036] The diagnosis unit is used to diagnose the aging state of the front oxygen sensor according to the first averaging period, the second averaging period and a preset threshold.

[0037] Preferably, the acquisition unit includes:

[0038] A comparison module, for comparing the crankshaft angle and the camshaft angle with the injection phase respectively;

[0039] A first determination module, configured to determine that the crankshaft angle, the camshaft angle, and the injection phase meet a 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 used to obtain the injection phase and speed of the injector during the injection action and continuously collect multiple Nernst voltage maximum values ​​within a preset number of cycles when the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition.

[0041] Preferably, it also includes:

[0042] a determination unit, configured to determine that the crankshaft angle, the camshaft angle, and the injection phase do not meet a synchronization condition when the crankshaft angle is inconsistent with the injection phase, or the camshaft angle is inconsistent with the injection phase;

[0043] The collecting unit is used for continuing to collect the crankshaft angle and camshaft angle of the engine and matching the injection phase when 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.

[0044] Preferably, the first computing unit comprises:

[0045] A statistical module, used for counting the corresponding number of teeth of the crankshaft or camshaft required for executing a preset number of injection actions according to the injection phase;

[0046] A conversion module, used for converting the rotation speed into a corresponding time of a single tooth;

[0047] The first calculation module is used to calculate the product of the corresponding time of the single tooth and the corresponding number of teeth to obtain a first average period required for executing a preset number of injection actions.

[0048] It can be known from the above technical scheme that the present application discloses a method and device for diagnosing the aging status of a front oxygen sensor, which relates to the field of vehicle sensor diagnosis technology, and collects the engine's crankshaft angle, camshaft angle and injection phase matched by the engine in real time. If the crankshaft angle, camshaft angle and injection phase meet the synchronization conditions, the injection phase and speed of the injector during the injection action are obtained, as well as multiple Nernst voltage maxima within a preset number of cycles. According to the injection phase and speed, the first average cycle required for executing a preset number of injection actions is calculated, and according to the multiple Nernst voltage maxima within the preset number of cycles, the second average cycle is calculated. According to the first average cycle, the second average cycle and the preset threshold, the aging status of the front oxygen sensor is diagnosed.

[0049] Through the above scheme, the engine injection state is judged in combination with the engine injection phase and the engine speed, so as to analyze the fluctuation of the excess air coefficient detected by the theoretical front oxygen sensor position, and then judge whether the front oxygen sensor is aged according to the first average cycle, the second average cycle and the preset threshold, which can effectively and real-time detect whether the front oxygen sensor is aged. In addition, the control logic of the electronic control system is guaranteed so that the air-fuel ratio is always kept near the set value, so that the fuel can be fully burned and the exhaust emissions are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0051] Figure 1 A schematic flow chart of a method for diagnosing the aging state of a front oxygen sensor disclosed in an embodiment of the present application;

[0052] Figure 2 A schematic flow chart of another method for diagnosing the aging state of a front oxygen sensor disclosed in an embodiment of the present application;

[0053] Figure 3 A schematic diagram of the structure of a front oxygen sensor aging status diagnosis device disclosed in an embodiment of the present application;

[0054] Figure 4 This is a schematic diagram of the structure of an electronic device disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0055] 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. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0057] As can be seen from the background technology, the existing method of diagnosing the aging state of the front oxygen sensor is to perform an overall detection when the other actuators of the engine fail. During the overall detection process, it is judged based on experience whether there is a problem with the front oxygen sensor, and it is impossible to detect in real time whether the front oxygen sensor is in an aging state. Therefore, how to detect in real time whether the front oxygen sensor is in an aging state is an urgent problem to be solved in this application.

[0058] In order to solve the above problems, the present application discloses a method and device for diagnosing the aging state of a front oxygen sensor, which collects the crankshaft angle, camshaft angle and injection phase matched by the engine in real time. If the crankshaft angle, camshaft angle and injection phase meet the synchronization conditions, the injection phase and speed of the injector during the injection action are obtained, as well as multiple Nernst voltage maximum values ​​within a preset number of cycles. According to the injection phase and speed, the first average cycle required for the execution of the preset number of injection actions is calculated, and the second average cycle is calculated according to the multiple Nernst voltage maximum values ​​within the preset number of cycles. According to the first average cycle, the second average cycle and the preset threshold, the aging state of the front oxygen sensor is diagnosed. Through the above scheme, the engine injection state is judged in combination with the engine injection phase and the engine speed, so as to analyze the fluctuation of the excess air coefficient detected by the theoretical front oxygen sensor position, and then judge whether the front oxygen sensor is aged according to the first average cycle, the second average cycle and the preset threshold, so as to effectively and real-time detect whether the front oxygen sensor is in an aging state. In addition, the control logic of the electronic control system is guaranteed so that the air-fuel ratio is always kept near the set value, so that the fuel can be fully burned and the exhaust emissions are reduced. The specific implementation method is described in detail through the following embodiments.

[0059] refer to Figure 1 As shown, a method for diagnosing the aging state of a front oxygen sensor disclosed in an embodiment of the present application is shown, and the method for diagnosing the aging state of a front oxygen sensor mainly includes the following steps:

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

[0061] The crankshaft position sensor can be used to collect the engine's crankshaft angle in real time. The crankshaft position sensor is a sensor used to detect the engine crankshaft angle and the top dead center of the piston. 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, that is, the crankshaft angle.

[0062] The camshaft position sensor can be used to collect the camshaft angle of the engine in real time. The camshaft position sensor is a sensor used to detect the rotational position of the camshaft. The camshaft position sensor is a cylinder identification and positioning device that inputs the camshaft position signal to the main control signal of the cylinder ECU ignition control.

[0063] The injection phase matched by the engine can be collected in real time through the 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 of the injector during the injection action are obtained, as well as multiple Nernst voltage maximum values ​​within a preset number of cycles.

[0065] The crankshaft angle, camshaft angle and injection phase are compared, that is, whether the crankshaft angle / camshaft angle is consistent with the phase angle of the injection action is determined. When the crankshaft angle / camshaft angle is consistent with the phase angle of the injection phase, the injector or jet starts to perform the injection action.

[0066] If the crankshaft / camshaft angle is inconsistent with the injection phase, the system will continue to collect and match the injection phase until the phases are consistent. When the phases are consistent, the system will start to detect the aging status of the front oxygen sensor.

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

[0068] Specifically, if the crankshaft angle, camshaft angle and injection phase meet the synchronization conditions, the injection phase and speed of the injector during the injection action are obtained, as well as the process of obtaining multiple Nernst voltage maximum values ​​within a preset number of cycles, as shown in A1-A3.

[0069] A1: Compare the crankshaft angle and camshaft angle 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, camshaft angle and injection phase meet the synchronization conditions.

[0071] Among them, the aging system for detecting the aging status of the front oxygen sensor collects the crankshaft and camshaft phase angles at the beginning of the detection, and determines whether they are consistent with the phase angle of the injection action. If they are consistent, it is considered that the injection action has been executed and the aging status detection begins.

[0072] A3: When the crankshaft angle, camshaft angle and injection phase meet the synchronization condition, the injector performs the injection action to obtain the injection phase and speed during the injection action of the injector and continuously collect multiple Nernst voltage maximum values ​​within a preset number of cycles (such as a).

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

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

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

[0076] Nernst voltage is a feedback electrical signal used by the oxygen sensor to detect the excess air coefficient and is strongly correlated with the excess air coefficient.

[0077] During the operation of the front oxygen sensor, when the concentration of the engine mixture is controlled in a very narrow range centered on the theoretical air-fuel ratio of 14.7, the fuel burns fully, and the emissions of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust are low. When the engine is running at idle speed, the fuel injection volume of the injection system increases, and some 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. The carbon particles adhere to the surface of the front oxygen sensor, causing its protective layer to peel off. The oxygen sensor will also accelerate aging due to excessive surface temperature, resulting in abnormal air-fuel ratio detection. In this regard, the present application proposes a method for detecting the aging state of the front oxygen sensor based on the characteristics of the fuel injection system of the electronic control unit.

[0078] When the crankshaft angle is inconsistent with the injection phase, or the camshaft angle is inconsistent with the injection phase, it is determined that the crankshaft angle, camshaft angle and injection phase do not meet the synchronization condition. When the crankshaft angle, camshaft angle and injection phase do not meet the synchronization condition, continue to collect the engine's crankshaft angle and camshaft angle and match the injection phase until the crankshaft angle and camshaft angle are consistent with the injection phase.

[0079] S103: Calculating a first average period required for executing a preset number of injection actions according to the injection phase and the rotation speed.

[0080] In S103, after the aging test is performed, the Nernst voltage value fed back by the front oxygen sensor is collected, and the maximum value of the preset number (a) of cycles is continuously calculated to ensure that the detected Nernst voltage is indeed a cycles. After that, the average time of the fluctuation of each cycle of the Nernst voltage is calculated. At the same time, the average cycle time required to perform a injection action is calculated in combination with the injection phase and the current speed value, that is, the first average cycle.

[0081] Among them, based on the characteristic phenomenon of oxygen sensor aging, once aging occurs, the change cycle of the Nernst voltage signal of the oxygen sensor will be delayed. In this regard, the execution time of the injection action (exhaust emissions affect the change of Nernst voltage) is compared with the response time of the actual Nernst voltage.

[0082] Specifically, the process of calculating the first average cycle required for executing a preset number of injection actions according to the injection phase and the rotation speed is shown in B1-B3.

[0083] B1: The corresponding number of crankshaft or camshaft teeth required to execute a preset number of injection actions according to the injection phase statistics.

[0084] B2: Convert the speed into the corresponding time of a single tooth.

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

[0086] Among them, the preset number is set according to the actual situation and this application does not make any specific limitation.

[0087] S104: Calculate a second average period according to a plurality of Nernst voltage maximum values ​​within a preset number of periods.

[0088] In S104, a plurality of Nernst voltage maximum values ​​within a preset number of cycles continuously collected are averaged to obtain a second average cycle.

[0089] Regardless of whether the front oxygen sensor is aged or not, when the speed is stable, the response time of the Nernst voltage of the front oxygen sensor will show an approximately stable periodic 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: diagnose the aging state of the front oxygen sensor according to the first averaging period, the second averaging period and the preset threshold.

[0091] After the results (first average cycle, second average cycle) are calculated, the first average cycle, second average cycle and preset threshold are compared. If the difference between the two cycles meets the set threshold, it is considered that the front oxygen sensor has no aging phenomenon; otherwise, it has aging phenomenon.

[0092] Among them, the preset threshold is set according to the actual situation and this application does not make any specific limitation.

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

[0094] C1: Calculate the difference between the first average period and the second average period to obtain the difference.

[0095] C2: Diagnose the aging status of the front oxygen sensor based on the difference and the preset threshold.

[0096] C3: During the diagnosis of the aging status of the front oxygen sensor, if the difference is less than or equal to the preset threshold, it is determined that the front oxygen sensor has no aging phenomenon.

[0097] C4: If the difference is greater than the preset threshold, it is determined that the front oxygen sensor is aged.

[0098] It should be noted that each fuel injection will cause a process from lean to rich and then back to lean for the exhaust gas 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 back to low. In this regard, if the exhaust gas has a cycle process, but the Nernst voltage does not, it can be considered that the corresponding cycle is slowing down and there is aging.

[0099] If aging occurs, it is recommended not to include it in the corporate standards / specifications.

[0100] In order to facilitate the understanding of a front oxygen sensor aging state diagnosis method, combined with Figure 2 Let's take an example:

[0101] Figure 2 In the process, the crankshaft angle and cam angle are collected;

[0102] Determine whether the crankshaft angle, camshaft angle and injection phase meet the synchronization conditions;

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

[0104] If yes, collect the energy voltage value of the front oxygen sensor and start to detect the aging status of the front oxygen sensor;

[0105] The average period required for executing a fuel injection action is calculated by comprehensively considering the fuel injection phase and the speed, that is, the first average period; wherein the value of a is an integer greater than or equal to 1;

[0106] Continuously collect the maximum value of the Nernst voltage for a period, and calculate the average period, that is, the second average period;

[0107] The first average period and the second average period are calculated to obtain the difference between the two periods, and the difference between the periods is compared to see whether it meets a preset threshold;

[0108] If so, make sure the front oxygen sensor is not aging;

[0109] If not, determine that the front oxygen sensor is aging.

[0110] This application can effectively detect the aging state of the front oxygen sensor, thereby ensuring the control logic of the electronic control system, so that the air-fuel ratio is always kept near the set value, so that the fuel can be fully burned and exhaust emissions are reduced. The key point of the conception of this application is to combine the engine injection phase. By judging the engine injection state, the fluctuation of the excess air coefficient detected by the theoretical front oxygen sensor position is analyzed, and then it is determined whether the front oxygen sensor is aged.

[0111] The beneficial effects of the embodiment of the present application are as follows: the engine injection state is judged by combining the engine injection phase and the engine speed, so as to analyze the fluctuation of the excess air coefficient detected by the theoretical front oxygen sensor position, and then judge whether the front oxygen sensor is aged according to the first average cycle, the second average cycle and the preset threshold, so as to effectively and in real time detect whether the front oxygen sensor is aged. In addition, the control logic of the electronic control system is guaranteed so that the air-fuel ratio is always kept near the set value, so that the fuel can be fully burned and the exhaust emissions are reduced.

[0112] Based on the above embodiments Figure 1 A front oxygen sensor aging state diagnosis method is disclosed, and the embodiment of the present application also discloses a front oxygen sensor aging state diagnosis device, such as Figure 3 As shown, the front oxygen sensor aging state diagnosis device includes:

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

[0114] The acquisition unit 302 is used to acquire the injection phase and speed of the injector during the injection action, and multiple Nernst voltage maximum values ​​within a preset number of cycles if the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition;

[0115] A first calculation unit 303, used for calculating a first average period required for executing a preset number of injection actions according to the injection phase and the rotation speed;

[0116] A second calculation unit 304, configured to calculate a second average period according to a plurality of Nernst voltage maximum values ​​within a preset number of periods;

[0117] The diagnosis unit 305 is used to diagnose the aging state of the front oxygen sensor according to the first averaging period, the second averaging period and the preset threshold.

[0118] Furthermore, the acquisition unit 302 includes:

[0119] A comparison module, for comparing the crankshaft angle and the camshaft angle with the injection phase, respectively;

[0120] A first determination module, for determining that the crankshaft angle, the camshaft angle and the injection phase meet a 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 used to obtain the injection phase and speed of the injector during the injection action and continuously collect multiple Nernst voltage maximum values ​​within a preset number of cycles when the crankshaft angle, camshaft angle and injection phase meet the synchronization conditions.

[0122] Furthermore, the front oxygen sensor aging state diagnosis device also includes:

[0123] a determination unit, 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 used to continue to acquire the crankshaft angle and camshaft angle of the engine and match the injection phase when the crankshaft angle, camshaft angle and injection phase do not meet the synchronization condition, until the crankshaft angle and camshaft angle are consistent with the injection phase.

[0125] Furthermore, the first calculation unit 303 includes:

[0126] A statistical module, used for counting the corresponding number of teeth of the crankshaft or camshaft required for executing a preset number of injection actions according to the injection phase;

[0127] A conversion module, used to convert the speed into the corresponding time of a single tooth;

[0128] The first calculation module is used to calculate the product of the corresponding time of a single tooth and the corresponding number of teeth to obtain a first average period required for executing a preset number of injection actions.

[0129] Furthermore, the second calculation unit 304 is specifically configured to average a plurality of Nernst voltage maximum values ​​continuously collected within a preset number of periods to obtain a second average period.

[0130] Furthermore, the diagnosis unit 305 includes:

[0131] A second calculation module is used to calculate the difference between the first average period and the second average period to obtain a difference value;

[0132] A diagnostic module, used for diagnosing the aging status of the front oxygen sensor based on the difference and a preset threshold;

[0133] A second determination module is used to determine that the front oxygen sensor has no aging phenomenon if the difference is less than or equal to a preset threshold value during the process of diagnosing the aging state of the front oxygen sensor;

[0134] The third determination module is used to determine that the front oxygen sensor is aged if the difference is greater than a preset threshold.

[0135] The beneficial effects of the embodiment of the present application are as follows: the engine injection state is judged by combining the engine injection phase and the engine speed, so as to analyze the fluctuation of the excess air coefficient detected by the theoretical front oxygen sensor position, and then judge whether the front oxygen sensor is aged according to the first average cycle, the second average cycle and the preset threshold, so as to effectively and in real time detect whether the front oxygen sensor is aged. In addition, the control logic of the electronic control system is guaranteed so that the air-fuel ratio is always kept near the set value, so that the fuel can be fully burned and the exhaust emissions are reduced.

[0136] An embodiment of the present application further provides a storage medium, which includes stored instructions, wherein when the instructions are executed, the device where the storage medium is located is controlled to execute the above-mentioned front oxygen sensor aging status diagnosis method.

[0137] The present application also provides an electronic device, whose structural diagram is as follows: Figure 4 As shown, it 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 one or more instructions 402 to perform the above-mentioned front oxygen sensor aging status diagnosis method.

[0138] For the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

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

[0140] The steps in the methods of the embodiments of the present application can be adjusted in order, combined, and deleted according to actual needs.

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

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

[0143] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for diagnosing the aging state of a front oxygen sensor, characterized in that: The method comprises: Real-time acquisition of the engine's crankshaft angle, camshaft angle, and injection phase matched by the engine; If the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, the injection phase and the rotation speed of the injector during the injection action, and multiple Nernst voltage maximum values ​​within a preset number of cycles are obtained; Calculating a first average period required for executing a preset number of injection actions according to the injection phase and the rotation speed; Calculating a second average period based on a plurality of Nernst voltage maximum values ​​within a preset number of periods; The aging state of the front oxygen sensor is diagnosed according to the first averaging period, the second averaging period and a preset threshold.

2. The method according to claim 1, characterized in that: If the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, the injection phase and the speed of the injector during the injection action are obtained, as well as multiple Nernst voltage maximum values ​​within a preset number of cycles, including: comparing the crankshaft angle and the camshaft angle with the injection phase respectively; When the crankshaft angle is consistent with the injection phase, and the camshaft angle is consistent with the injection phase, determining that the crankshaft angle, the camshaft angle, and the injection phase meet a synchronization condition; When the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition, the injector performs an injection action to obtain the injection phase and rotation speed during the injection action of the injector and continuously collect multiple Nernst voltage maximum values ​​within a preset number of cycles.

3. The method according to claim 2, characterized in that Also includes: When the crankshaft angle is inconsistent with the injection phase, or the camshaft angle is inconsistent with the injection phase, determining that the crankshaft angle, the camshaft angle, and the injection phase do not meet the synchronization condition; When 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 continue to be collected and the injection phase is matched until the crankshaft angle and the camshaft angle are consistent with the injection phase.

4. The method according to claim 1, characterized in that: The step of calculating a first average period required for executing a preset number of injection actions according to the injection phase and the rotation speed includes: The corresponding number of teeth of the crankshaft or camshaft required for executing a preset number of injection actions according to the injection phase statistics; Convert the speed into the corresponding time of a single tooth; The corresponding time of the single tooth and the corresponding number of teeth are multiplied to obtain a first average period required for executing a preset number of injection actions.

5. The method according to claim 1, characterized in that The step of calculating the second average period according to a plurality of Nernst voltage maximum values ​​within a preset number of periods includes: The plurality of Nernst voltage maximum values ​​within a preset number of cycles continuously collected are averaged to obtain a second average cycle.

6. The method according to claim 1, characterized in that The diagnosing the aging state of the front oxygen sensor according to the first averaging period, the second averaging period and the preset threshold value includes: Calculate the difference between the first average period and the second average period to obtain a difference value; diagnosing the aging state of the front oxygen sensor according to the difference and a preset threshold; During the process of diagnosing the aging state of the front oxygen sensor, if the difference is less than or equal to the preset threshold, it is determined that the front oxygen sensor has no aging phenomenon; If the difference is greater than the preset threshold, it is determined that the front oxygen sensor is aged.

7. A front oxygen sensor aging status diagnosis device, characterized in that: The device comprises: A real-time acquisition unit, used for real-time acquisition of the engine's crankshaft angle, camshaft angle, and injection phase matched by the engine; an acquisition unit, configured to acquire the injection phase and rotation speed of the injector during the injection operation, and multiple Nernst voltage maximum values ​​within a preset number of cycles if the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition; A first calculation unit, configured to calculate a first average period required for executing a preset number of injection actions according to the injection phase and the rotation speed; A second calculation unit, used for calculating a second average period according to a plurality of Nernst voltage maximum values ​​within a preset number of periods; The diagnosis unit is used to diagnose the aging state of the front oxygen sensor according to the first averaging period, the second averaging period and a preset threshold.

8. The device according to claim 7, characterized in that The acquisition unit comprises: A comparison module, for comparing the crankshaft angle and the camshaft angle with the injection phase respectively; A first determination module, configured to determine that the crankshaft angle, the camshaft angle, and the injection phase meet a 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 used to obtain the injection phase and speed of the injector during the injection action and continuously collect multiple Nernst voltage maximum values ​​within a preset number of cycles when the crankshaft angle, the camshaft angle and the injection phase meet the synchronization condition.

9. The device according to claim 8, characterized in that Also includes: a determination unit, configured to determine that the crankshaft angle, the camshaft angle, and the injection phase do not meet a synchronization condition when the crankshaft angle is inconsistent with the injection phase, or the camshaft angle is inconsistent with the injection phase; The collecting unit is used for continuing to collect the crankshaft angle and camshaft angle of the engine and matching the injection phase when 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.

10. The device according to claim 7, characterized in that The first computing unit comprises: A statistical module, used for counting the corresponding number of teeth of the crankshaft or camshaft required for executing a preset number of injection actions according to the injection phase; A conversion module, used for converting the rotation speed into a corresponding time of a single tooth; The first calculation module is used to calculate the product of the corresponding time of the single tooth and the corresponding number of teeth to obtain a first average period required for executing a preset number of injection actions.

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