CN114370347B - Diagnosis method and device for rear oxygen sensor, vehicle and storage medium - Google Patents
Diagnosis method and device for rear oxygen sensor, vehicle and storage medium Download PDFInfo
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- CN114370347B CN114370347B CN202210067263.9A CN202210067263A CN114370347B CN 114370347 B CN114370347 B CN 114370347B CN 202210067263 A CN202210067263 A CN 202210067263A CN 114370347 B CN114370347 B CN 114370347B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/22—Safety or indicating devices for abnormal conditions
- F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0002—Controlling intake air
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0002—Controlling intake air
- F02D2041/0022—Controlling intake air for diesel engines by throttle control
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
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- Combustion & Propulsion (AREA)
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- General Engineering & Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Measuring Oxygen Concentration In Cells (AREA)
Abstract
The invention relates to the technical field of vehicles, and particularly discloses a diagnosis method, a device, a vehicle and a storage medium of a rear oxygen sensor. The diagnosis method can effectively improve the diagnosis accuracy of the rear oxygen sensor in the atmosphere, reduce the requirement on the signal quality of the rear oxygen sensor, improve the detection efficiency, and avoid the situation that the rear oxygen sensor cannot be accurately diagnosed due to the adoption of cheating means; the method can be combined with active diagnosis of the catalytic efficiency of the three-way catalyst, optimizes the diagnosis process and does not influence the normal emission level of the engine.
Description
Technical Field
The present invention relates to the field of vehicle technologies, and in particular, to a method and apparatus for diagnosing a rear oxygen sensor, a vehicle, and a storage medium.
Background
The post-oxygen sensor is an important part in the post-treatment system and bears an important task of diagnosing the working state of the three-way catalyst, the working state of the three-way catalyst directly influences whether the exhaust emission can reach the standard, and if the post-oxygen sensor fails or is placed in the air, CO and NO are easily caused X CH compounds, etc. are out of limits.
In the prior art, a judgment method for the presence of the rear oxygen sensor in the air generally uses the difference between the current rear oxygen sensor voltage signal and the rear oxygen sensor voltage signal measured in the previous ECU scheduling period to take an absolute value, then compares the absolute value with a set limit value, counts once if the absolute value is smaller than the limit value, and reports a fault after the continuous count reaches a target value. The existing diagnosis of whether the rear oxygen sensor is placed in the air or not needs to be carried out by means of the voltage signal difference value of two cycles, the requirement on the signal quality of the sensor is higher, the requirement time for completing the diagnosis is longer, meanwhile, the existing diagnosis process of whether the rear oxygen sensor is placed in the air or not is not necessarily related to the active diagnosis of the catalytic efficiency of the three-way catalyst, and the emission pollutants in the active diagnosis process of the three-way catalyst can be increased greatly.
Disclosure of Invention
The invention aims at: a method, apparatus, vehicle and storage medium for diagnosing a rear oxygen sensor are provided to solve the problem of long diagnosis period of whether the rear oxygen sensor is placed in the air in the related art.
In one aspect, the present invention provides a method of diagnosing a post-oxygen sensor, the method comprising:
starting an engine;
confirming whether the activated oxygen sensor is placed in the air or not to meet the diagnosis enable;
the fuel in the combustion chamber of the engine is insufficiently combusted in insufficient air;
collecting a first detection voltage value of the rear oxygen sensor after a first set time;
and diagnosing whether the rear oxygen sensor is placed in the air or not based on the first detection voltage value, and outputting a first diagnosis result.
As a preferable mode of the diagnosis method of the post-oxygen sensor, diagnosing whether the post-oxygen sensor is placed in the air based on the first detection voltage value includes:
comparing the magnitudes of the first detection voltage and an upper voltage threshold;
if the first detection voltage is not greater than the upper voltage threshold;
then the rear oxygen sensor is determined to be in the air and an alarm is given.
As a preferable mode of the diagnosis method of the post-oxygen sensor, if the first detection voltage is greater than the upper voltage threshold;
fully burning fuel in the combustion chamber of the engine in excessive air;
collecting a second detection voltage value of the rear oxygen sensor after a second set time;
and diagnosing whether the rear oxygen sensor is placed in the air based on the second detection voltage value, and outputting a second diagnosis result.
As a preferable mode of the diagnosis method of the post-oxygen sensor, diagnosing whether the post-oxygen sensor is placed in the air based on the second detection voltage value includes:
comparing the magnitudes of the second detection voltage and a lower voltage threshold;
if the second detection voltage is not smaller than the lower voltage threshold value;
then the rear oxygen sensor is determined to be in the air and an alarm is given.
As a preferable mode of the diagnosis method of the post-oxygen sensor, if the second detection voltage is smaller than the lower voltage threshold;
it is determined that the rear oxygen sensor is not placed in the air.
As a preferable embodiment of the diagnostic method of the post-oxygen sensor, the insufficient combustion of the fuel in the engine combustion chamber in the insufficient air includes:
air having an air excess ratio of greater than 1, which is the ratio of the amount of air actually supplied with fuel for combustion to the theoretical amount of air required for the fuel to be fully combusted, is supplied to the combustion chamber of the engine.
As a preferable embodiment of the diagnostic method of the post-oxygen sensor, the method of sufficiently combusting the fuel in the combustion chamber of the engine in the excessive air includes:
air having an air excess ratio of less than 1, which is a ratio of an amount of air actually supplied with fuel for combustion to a theoretical amount of air required for sufficient combustion of the fuel, is supplied to a combustion chamber of an engine.
In another aspect, the present invention also provides a diagnostic device of a post-oxygen sensor, including:
a starting unit for starting the engine;
an enable confirmation unit for confirming that the diagnostic enable of whether the activated oxygen sensor is placed in the air is satisfied;
a first execution unit for insufficiently combusting fuel in a combustion chamber of the engine in insufficient air;
the first timing acquisition unit is used for acquiring a first detection voltage value of the rear oxygen sensor after a first set time;
and the first diagnosis module is used for diagnosing whether the rear oxygen sensor is placed in the air or not based on the first detection voltage value and outputting a first diagnosis result.
In another aspect, the present disclosure also provides a vehicle including an engine and an aftertreatment system coupled to the engine, the aftertreatment system including a three-way catalyst and a post-oxygen sensor, the vehicle further including:
a driving controller;
the temperature sensor is used for detecting the temperature of the post-processing system and sending the temperature to the driving controller;
an intake air regulating valve for regulating an amount of air input to an intake manifold of the engine;
an instrument panel for alarming when the rear oxygen sensor is determined to be placed in the air;
a memory for storing one or more programs;
the one or more programs, when executed by the drive controller, cause the vehicle to implement a method of diagnosing a rear oxygen sensor as described in any of the above aspects.
In another aspect, the present invention also provides a storage medium having stored thereon a computer program which, when executed by a vehicle controller, implements a method of diagnosing a post-oxygen sensor as described in any one of the above aspects.
The beneficial effects of the invention are as follows:
the invention provides a diagnosis method, a diagnosis device, a vehicle and a storage medium of a rear oxygen sensor, wherein after an engine is started, when the condition that whether the activated rear oxygen sensor is placed in air or not is confirmed to be enabled is met, fuel in a combustion chamber of the engine is not fully combusted in insufficient air, then a first detection voltage value of the rear oxygen sensor is acquired after a first set time, whether the rear oxygen sensor is placed in air or not is diagnosed based on the first detection voltage value, and a first diagnosis result is output. The voltage change of the rear oxygen sensor is monitored by actively adjusting the excess air coefficient, so that the diagnosis accuracy of the rear oxygen sensor in the atmosphere is greatly improved, the requirement on the signal quality of the rear oxygen sensor is reduced, the detection efficiency can be improved, and meanwhile, the condition that the rear oxygen sensor cannot be accurately diagnosed due to the adoption of cheating means can be avoided. Meanwhile, the diagnosis method is realized by actively adjusting the excess air coefficient, can be combined with active diagnosis of the catalytic efficiency of the three-way catalyst, optimizes the diagnosis process and does not influence the normal emission level of the engine.
Drawings
FIG. 1 is a flow chart of a method for diagnosing a post-oxygen sensor according to an embodiment of the present invention;
FIG. 2 is a second flowchart of a method for diagnosing a post-oxygen sensor according to an embodiment of the present invention;
FIG. 3 is a schematic diagram showing a structure of a diagnostic device of a rear oxygen sensor according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a vehicle according to an embodiment of the present invention.
In the figure:
300. a starting unit; 310. an enable confirmation unit; 320. a first execution unit; 330. a first timing acquisition unit; 340. a first diagnostic module;
400. an engine; 410. a rear oxygen sensor; 420. a three-way catalyst; 430. a driving controller; 440. a temperature sensor; 450. an intake air regulating valve; 460. a dashboard; 470. a memory.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first location" and "second location" are two distinct locations and wherein the first feature is "above," "over" and "over" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is level above the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.
Example 1
In the prior art, a judgment method for the presence of the rear oxygen sensor in the air generally uses the difference between the current rear oxygen sensor voltage signal and the rear oxygen sensor voltage signal measured in the previous ECU scheduling period to take an absolute value, then compares the absolute value with a set limit value, counts once if the absolute value is smaller than the limit value, and reports a fault after the continuous count reaches a target value. The existing diagnosis of whether the rear oxygen sensor is placed in the air or not needs to be carried out by means of the voltage signal difference value of two cycles, the requirement on the signal quality of the sensor is higher, the requirement time for completing the diagnosis is longer, meanwhile, the existing diagnosis process of whether the rear oxygen sensor is placed in the air or not is not necessarily related to the active diagnosis of the catalytic efficiency of the three-way catalyst, and the emission pollutants in the active diagnosis process of the three-way catalyst can be increased greatly.
In this regard, the present embodiment provides a method for diagnosing a rear oxygen sensor, which can be implemented by a diagnostic device of a rear oxygen sensor that can be implemented by software and/or hardware and integrated in a vehicle, to solve the above-described technical problems, and in particular, the method for diagnosing a rear oxygen sensor includes the following steps.
S100: the engine is started.
S110: confirm that the diagnostic enablement of whether the oxygen sensor is in air after activation is satisfied.
The diagnosis of whether the rear oxygen sensor is placed in the air can be performed according to one or more of whether the engine is normally operated, whether the engine has a rotating speed signal, whether the exhaust temperature of the engine is normal and does not reach a catalyst damage limit value, whether the current battery voltage meets the minimum requirement, whether the oxygen sensor has exceeded a dew point, and whether the exhaust emission exceeds the standard. For example, when all conditions are used to confirm that the oxygen sensor is placed in the air after activation is diagnostic enabled, when the engine is in a normal operating state; the engine speed signal can be normally detected; comparing the exhaust temperature with the catalyst damage limit temperature to judge that the exhaust temperature of the engine is sufficient, wherein the exhaust temperature does not reach the catalyst damage limit temperature; the oxygen sensor is over dew point; the oxygen sensor is ready for heating; when harmful gases such as CO, HC and NOx discharged from the tail gas are all satisfied within the range required by regulations, the satisfaction of the diagnosis enabling of whether the activated oxygen sensor is placed in the air can be confirmed.
S120: the fuel in the engine combustion chamber is insufficiently combusted in the insufficient air.
In this embodiment, the fuel in the combustion chamber of the engine is insufficiently combusted in the insufficient air by supplying the air having an excess air ratio greater than 1 to the combustion chamber of the engine. Wherein the excess air ratio is the ratio of the amount of air actually supplied to the fuel for combustion to the theoretical amount of air required for the fuel to be fully combusted.
Specifically, the amount of air entering the intake manifold may be regulated by an intake control valve. When the fuel injected from the fuel injector is fixed, a theoretical air amount required for sufficient combustion thereof can be determined based on the fixed fuel, a specific opening degree of the intake control valve can be confirmed based on the theoretical air amount, a determined intake time and a determined intake pressure, and when it is necessary to supply air having an air excess coefficient of more than 1 to the combustion chamber of the engine, the opening degree of the intake control valve can be adjusted to be lower on the basis of the specific opening degree. The value of the excess air ratio of less than 1 may be set as desired, and for example, the excess air ratio may be one of 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, and the like.
Note that in this embodiment, when the fuel is not fully combusted, the oxygen content in the air in the mixed gas after the fuel combustion is not limited to zero, and the fuel may be considered to be insufficiently combusted when there is a large amount of unreacted fuel and a small amount of unreacted oxygen.
S130: and collecting a first detection voltage value of the rear oxygen sensor after a first set time.
It is understood that the air excess factor supplied to the combustion chamber of the engine in S120 is kept unchanged for the first set time. The first setting time can be set according to requirements.
S140: and diagnosing whether the rear oxygen sensor is placed in the air based on the first detection voltage value, and outputting a first diagnosis result.
It will be appreciated that the first detection voltage value will be large when the rear oxygen sensor is not in air, and will be relatively small when the rear oxygen sensor is in air, due to insufficient combustion of fuel, so that a direct diagnosis can be made as to whether the rear oxygen sensor is in air or not, based on the first detection voltage value.
After the engine is started, when it is confirmed that the diagnosis enabling of whether the activated oxygen sensor is placed in the air is satisfied, fuel in a combustion chamber of the engine is not fully combusted in the insufficient air, then a first detection voltage value of the oxygen sensor is acquired after a first set time, whether the oxygen sensor is placed in the air is diagnosed based on the first detection voltage value, and a first diagnosis result is output. Compared with the prior art, the voltage change of the rear oxygen sensor is monitored by actively adjusting the excess air coefficient, so that the diagnosis accuracy of the rear oxygen sensor in the atmosphere is greatly improved, the requirement on the signal quality of the rear oxygen sensor is reduced, the detection efficiency can be improved, and meanwhile, the condition that the rear oxygen sensor cannot be accurately diagnosed due to the adoption of cheating means can be avoided. Meanwhile, the diagnosis method is realized by actively adjusting the excess air coefficient, can be combined with active diagnosis of the catalytic efficiency of the three-way catalyst, optimizes the diagnosis process and does not influence the normal emission level of the engine.
Example two
Fig. 2 is a flowchart of a diagnosis method of a post-oxygen sensor according to a second embodiment of the present invention, where the diagnosis method of the post-oxygen sensor is embodied based on the above embodiment, and includes the following steps:
s200: the engine is started.
S210: confirm that the diagnostic enablement of whether the oxygen sensor is in air after activation is satisfied.
S220: the fuel in the engine combustion chamber is insufficiently combusted in the insufficient air.
S230: and collecting a first detection voltage value of the rear oxygen sensor after a first set time.
S240: and diagnosing whether the rear oxygen sensor is placed in the air based on the first detection voltage value, and outputting a first diagnosis result.
Wherein S240 specifically includes:
s241: comparing the magnitudes of the first detection voltage and the upper voltage threshold;
if the first detection voltage is not greater than the upper voltage threshold, then S242 is performed; if the first detection voltage is greater than the upper voltage threshold, S250 is performed.
S242: and (5) after the determination, placing the oxygen sensor in the air and giving an alarm.
When the first detection voltage is not greater than the upper voltage threshold, it may be clearly indicated that the rear oxygen sensor is placed in air. At this time, the alarm prompt can be carried out through any one or more of an instrument panel and an audible and visual alarm device. Wherein the upper voltage threshold is set based on the specific model of the post-oxygen sensor.
S250: the fuel in the engine combustion chamber is fully combusted in excess air.
Specifically, in the present embodiment, the fuel in the combustion chamber of the engine is sufficiently combusted in the excessive air by supplying the air having an excess air ratio greater than 1 to the combustion chamber of the engine.
If the first detection voltage is greater than the upper voltage threshold, it cannot be diagnosed whether the post-oxygen sensor is placed in air. In this embodiment, it is further determined whether the post-diagnosis oxygen sensor is placed in the air by adjusting the excess air ratio. Wherein the excess air ratio is adjusted to be greater than 1 and less than 1, so that the fuel supplied to the engine can be combusted sufficiently. The value of the excess air ratio greater than 1 may be set as desired, and for example, the excess air ratio may be one of 1.1, 1.15, 1.2, 1.25, 1.3, and the like.
It should be noted that in this embodiment, when the fuel is fully combusted, a large amount of oxygen in the air is still available in the mixed gas after the fuel is combusted, and the amount of the fuel after the combustion may be zero or may be very small.
S260: and collecting a second detection voltage value of the rear oxygen sensor after a second set time.
It is understood that the air excess factor supplied to the combustion chamber of the engine in S120 is kept unchanged for the second set time. The second setting time can be set according to the requirement.
S270: and diagnosing whether the rear oxygen sensor is placed in the air based on the second detection voltage value, and outputting a second diagnosis result.
It will be appreciated that since the fuel is fully combusted, the first detected voltage value will be small when the rear oxygen sensor is not in air, and will be relatively large when the rear oxygen sensor is in air, and thus a direct diagnosis can be made as to whether the rear oxygen sensor is in air or not based on the second detected voltage value.
Wherein S270 specifically includes:
s271: the magnitudes of the second detection voltage and the lower voltage threshold are compared.
If the second detection voltage is not less than the lower voltage threshold; s272 is performed, and if the second detection voltage is smaller than the lower voltage threshold, S273 is performed.
S272: and (5) after the determination, placing the oxygen sensor in the air and giving an alarm.
When the second detection voltage is not less than the lower voltage threshold, it can be clearly indicated that the rear oxygen sensor is placed in the air. At this time, the alarm prompt can be carried out through any one or more of an instrument panel and an audible and visual alarm device. Wherein the lower voltage threshold is set based on the specific model of the post-oxygen sensor.
S273: it was determined that the oxygen sensor was not placed in air.
When the second detection voltage is less than the lower voltage threshold, it may be clearly indicated that the rear oxygen sensor is not placed in air. At the moment, the instrument panel can remind the driver that the rear oxygen sensor has no fault.
The method for diagnosing a post-oxygen sensor according to the present embodiment is further diagnosed by adjusting the excess air ratio to be greater than 1 when it is not possible to clearly determine whether the post-oxygen sensor is in the air if the excess air ratio is less than 1, based on the method for diagnosing a post-oxygen sensor according to the first embodiment. Compared with the prior art, the voltage change of the rear oxygen sensor is monitored by actively adjusting the excess air coefficient, so that the diagnosis accuracy of the rear oxygen sensor in the atmosphere is greatly improved, the requirement on the signal quality of the rear oxygen sensor is reduced, the detection efficiency can be improved, and meanwhile, the condition that the rear oxygen sensor cannot be accurately diagnosed due to the adoption of cheating means can be avoided. Meanwhile, the diagnosis method is realized by actively adjusting the excess air coefficient, can be combined with active diagnosis of the catalytic efficiency of the three-way catalyst, optimizes the diagnosis process and does not influence the normal emission level of the engine.
Example III
Fig. 3 is a schematic structural diagram of a diagnostic device of a post-oxygen sensor provided in the third embodiment, which is used to perform the diagnostic method of the post-oxygen sensor in the above embodiment. Specifically, the diagnostic device of the post-oxygen sensor includes a start unit 300, an enable confirmation unit 310, a first execution unit 320, a first timing acquisition unit 330, and a first diagnostic module 340.
The starting unit 300 is used to start the engine.
The enable confirmation unit 310 serves to confirm that the diagnostic enable of whether the activated oxygen sensor is placed in the air is satisfied.
The first execution unit 320 is configured to insufficiently combust fuel in the engine combustion chamber in insufficient air.
The first timing acquisition unit 330 is used for acquiring a first detection voltage value of the post-oxygen sensor after a first set time.
The first diagnosis module 340 is configured to diagnose whether the rear oxygen sensor is placed in the air based on the first detection voltage value, and output a first diagnosis result.
Specifically, the first diagnostic module 340 includes:
a first comparing unit for comparing the magnitudes of the first detection voltage and the upper voltage threshold;
a first determination unit for determining that the rear oxygen sensor is placed in air when the first detection voltage is not greater than the upper voltage threshold;
and the first alarm unit is used for giving an alarm when the oxygen sensor is determined to be placed in the air.
Optionally, the diagnosis of the post-oxygen sensor further comprises:
and the second execution unit is used for fully combusting fuel in the combustion chamber of the engine in excessive air.
The second timing acquisition unit is used for acquiring a second detection voltage value of the rear oxygen sensor after a second set time.
The second diagnosis module is used for diagnosing whether the rear oxygen sensor is placed in the air or not based on the second detection voltage value and outputting a second diagnosis result.
Wherein the second diagnostic module comprises:
a second comparing unit for comparing the magnitudes of the second detection voltage and the lower voltage threshold;
a second determination unit for determining that the rear oxygen sensor is placed in the air when the second detection voltage is not less than the lower voltage threshold;
and a third determination unit for determining that the post-oxygen sensor is located in the air when the second detection voltage is smaller than the lower voltage threshold.
And the second alarm unit is used for prompting that the rear oxygen sensor is normal when the rear oxygen sensor is determined not to be placed in the air.
The third embodiment of the invention provides a diagnosis device of a rear oxygen sensor, which starts an engine through a starting unit; the first execution unit is used for enabling fuel in a combustion chamber of the engine to be insufficiently combusted in insufficient air, the first timing acquisition unit is used for acquiring a first detection voltage value of the rear oxygen sensor after a first set time, the first diagnosis module is used for diagnosing whether the rear oxygen sensor is placed in the air or not based on the first detection voltage value, and a first diagnosis result is output. Compared with the prior art, the voltage change of the rear oxygen sensor is monitored by actively adjusting the excess air coefficient, so that the diagnosis accuracy of the rear oxygen sensor in the atmosphere is greatly improved, the requirement on the signal quality of the rear oxygen sensor is reduced, the detection efficiency can be improved, and meanwhile, the condition that the rear oxygen sensor cannot be accurately diagnosed due to the adoption of cheating means can be avoided. Meanwhile, the diagnosis method is realized by actively adjusting the excess air coefficient, can be combined with active diagnosis of the catalytic efficiency of the three-way catalyst, optimizes the diagnosis process and does not influence the normal emission level of the engine.
Example IV
Fig. 4 is a schematic structural diagram of a vehicle according to a fourth embodiment of the present invention. As shown in FIG. 4, the vehicle includes an engine 400 and an engine-coupled aftertreatment system, wherein the aftertreatment system includes a three-way catalyst 420 and a post-oxygen sensor 410. The vehicle further includes a drive controller 430, a temperature sensor 440, an intake air regulator 450, an instrument panel 460, and a memory. The driving controller 430 may be connected to the engine 400, the rear oxygen sensor 410, the three-way catalyst 420, the temperature sensor 440, the intake air adjusting valve 450, the instrument panel 460, and the memory 470 through a bus, or may be connected through other manners, where fig. 4 shows the manner of bus connection. The temperature sensor 440 is configured to detect a temperature of the aftertreatment system and send the detected temperature to the vehicle controller 430, and the vehicle controller 430 compares the detected temperature with a set temperature, and when the detected temperature is less than the set temperature, the temperature sensor indicates that the aftertreatment temperature is normal, so that it can be confirmed that the diagnostic enable of whether the activated oxygen sensor 410 is in the air is satisfied. The intake air adjusting valve 450 is used to adjust the amount of air input to the intake manifold of the engine 400, and thus the amount of air supplied to the fuel in the combustion chamber of the engine 400, so that the fuel in the combustion chamber of the engine 400 is not sufficiently combusted in insufficient air or the fuel in the combustion chamber of the engine 400 is sufficiently combusted in excessive air, and the instrument panel 460 is used to alarm when it is determined that the rear oxygen sensor 410 is placed in air.
The memory 470 serves as a computer readable storage medium, and may be used to store a software program, a computer executable program, and modules, such as program instructions/modules corresponding to the diagnostic method of the post-oxygen sensor 410 in the embodiment of the present invention. The driving controller 430 performs various functional applications of the vehicle and data processing by running software programs, instructions and modules stored in the memory 470, that is, implements the diagnostic method of the rear oxygen sensor 410 of the above-described embodiment.
Memory 470 primarily includes a program storage area and a data storage area, wherein the program storage area may store an operating system, at least one application program required for functionality; the storage data area may store data created according to the use of the terminal, etc. In addition, the memory 470 may include high-speed random access memory 470 and may also include non-volatile memory 470, such as at least one disk memory 470 piece, flash memory device, or other non-volatile solid state memory 470 piece. In some examples, the memory 470 may further include memory 470 located remotely from the ride control 430, and these remote memories 470 may be connected to the vehicle via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
The vehicle provided in the fourth embodiment of the present invention belongs to the same inventive concept as the diagnosis method of the post-oxygen sensor 410 provided in the above embodiment, and technical details not described in detail in the present embodiment can be seen in the above embodiment, and the present embodiment has the same advantageous effects of executing the diagnosis method of the post-oxygen sensor 410.
Example five
A fifth embodiment of the present invention also provides a storage medium having stored thereon a computer program which, when executed by a driving controller, implements the diagnostic method of a post-oxygen sensor according to the above-described embodiment of the present invention.
Of course, the storage medium containing the computer executable instructions provided by the embodiment of the invention is not limited to the operations in the diagnosis method of the post-oxygen sensor, but can also execute the related operations in the diagnosis device of the post-oxygen sensor provided by the embodiment of the invention, and has corresponding functions and beneficial effects.
From the above description of embodiments, it will be clear to a person skilled in the art that the present invention may be implemented by means of software and necessary general purpose hardware, but of course also by means of hardware, although in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a computer readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, etc., and include several instructions for causing a computer device (which may be a robot, a personal computer, a server, or a network device, etc.) to perform the diagnostic method of a post oxygen sensor according to the embodiments of the present invention.
It is to be understood that the above examples of the present invention are provided for clarity of illustration only and are not limiting of the embodiments of the present invention. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.
Claims (7)
1. A method of diagnosing a post-oxygen sensor, comprising:
starting an engine;
confirming whether the activated oxygen sensor is placed in the air or not to meet the diagnosis enable;
the fuel in the combustion chamber of the engine is insufficiently combusted in insufficient air;
collecting a first detection voltage value of the rear oxygen sensor after a first set time;
diagnosing whether the rear oxygen sensor is placed in the air or not based on the first detection voltage value, and outputting a first diagnosis result;
diagnosing whether the rear oxygen sensor is placed in air based on the first detected voltage value includes:
comparing the magnitudes of the first detection voltage and an upper voltage threshold;
if the first detection voltage is not greater than the upper voltage threshold;
then the rear oxygen sensor is determined to be placed in the air and an alarm is given;
if the first detection voltage is greater than the upper voltage threshold;
fully burning fuel in the combustion chamber of the engine in excessive air;
collecting a second detection voltage value of the rear oxygen sensor after a second set time;
diagnosing whether the rear oxygen sensor is placed in the air or not based on the second detection voltage value, and outputting a second diagnosis result;
diagnosing whether the rear oxygen sensor is placed in air based on the second detection voltage value includes:
comparing the magnitudes of the second detection voltage and a lower voltage threshold;
if the second detection voltage is not smaller than the lower voltage threshold value;
then the rear oxygen sensor is determined to be in the air and an alarm is given.
2. The method of diagnosing a post-oxygen sensor according to claim 1, wherein if the second detection voltage is less than the lower voltage threshold;
it is determined that the rear oxygen sensor is not placed in the air.
3. The method of diagnosing a post-oxygen sensor according to claim 1, wherein the undercombusting the fuel in the engine combustion chamber in the insufficient air includes:
air having an air excess ratio of greater than 1, which is the ratio of the amount of air actually supplied with fuel for combustion to the theoretical amount of air required for the fuel to be fully combusted, is supplied to the combustion chamber of the engine.
4. The method of diagnosing a post-oxygen sensor according to claim 1, wherein fully combusting fuel in the engine combustion chamber in excess air comprises:
air having an air excess ratio of less than 1, which is a ratio of an amount of air actually supplied with fuel for combustion to a theoretical amount of air required for sufficient combustion of the fuel, is supplied to a combustion chamber of an engine.
5. A diagnostic device of a post-oxygen sensor for performing the diagnostic method of a post-oxygen sensor of any one of claims 1-4, comprising:
a starting unit for starting the engine;
an enable confirmation unit for confirming that the diagnostic enable of whether the activated oxygen sensor is placed in the air is satisfied;
a first execution unit for insufficiently combusting fuel in a combustion chamber of the engine in insufficient air;
the first timing acquisition unit is used for acquiring a first detection voltage value of the rear oxygen sensor after a first set time;
and the first diagnosis module is used for diagnosing whether the rear oxygen sensor is placed in the air or not based on the first detection voltage value and outputting a first diagnosis result.
6. A vehicle comprising an engine and an aftertreatment system coupled to the engine, the aftertreatment system including a three-way catalyst and a post-oxygen sensor, further comprising:
a driving controller;
the temperature sensor is used for detecting the temperature of the post-processing system and sending the temperature to the driving controller;
an intake air regulating valve for regulating an amount of air input to an intake manifold of the engine;
an instrument panel for alarming when the rear oxygen sensor is determined to be placed in the air;
a memory for storing one or more programs;
when the one or more programs are executed by the drive controller, cause the vehicle to implement the diagnostic method of the post-oxygen sensor of any one of claims 1-4.
7. A storage medium having a computer program stored thereon, which when executed by a vehicle controller implements the diagnostic method of a post-oxygen sensor according to any one of claims 1-4.
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| CN202210067263.9A CN114370347B (en) | 2022-01-20 | 2022-01-20 | Diagnosis method and device for rear oxygen sensor, vehicle and storage medium |
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| KR101619597B1 (en) * | 2014-08-01 | 2016-05-10 | 현대자동차주식회사 | Method for detecting fault of rear oxygen sensor |
| CN107165711A (en) * | 2017-07-25 | 2017-09-15 | 中国第汽车股份有限公司 | The post oxygen sensor online test method of catalyst converter |
| CN110863917A (en) * | 2019-11-26 | 2020-03-06 | 奇瑞汽车股份有限公司 | Diagnostic method of oxygen sensor |
| CN113561958B (en) * | 2021-07-22 | 2023-07-25 | 东风汽车集团股份有限公司 | Dynamic response diagnosis method and system for rear oxygen sensor of hybrid electric vehicle |
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