CN113803140B - Method for diagnosing credibility of exhaust temperature sensor - Google Patents
Method for diagnosing credibility of exhaust temperature sensor Download PDFInfo
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- CN113803140B CN113803140B CN202010529854.4A CN202010529854A CN113803140B CN 113803140 B CN113803140 B CN 113803140B CN 202010529854 A CN202010529854 A CN 202010529854A CN 113803140 B CN113803140 B CN 113803140B
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- temperature
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
- F01N11/002—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
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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
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2260/00—Exhaust treating devices having provisions not otherwise provided for
- F01N2260/02—Exhaust treating devices having provisions not otherwise provided for for cooling the device
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
- F01N2560/06—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a temperature sensor
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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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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
The invention provides a method for diagnosing the credibility of an exhaust temperature sensor, which comprises the following steps: step S1: the temperature value measured by the sensor and the reference temperature after the ECU is electrified are stored into an array; step S2: judging whether the engine enters an operating state or not when the engine starts, if not, continuously detecting the temperature, and if so, carrying out the next step; step S3: averaging the temperature values measured by the two groups of sensors stored in the array and the reference temperature; step S4: then taking the difference of the two average values as an absolute value; step S5: inquiring a calibrated CUR curve by utilizing the cooling time of the engine to obtain a threshold value of the temperature difference; step S6: if the absolute value of the temperature difference is greater than the threshold value of the obtained temperature difference, the temperature measured by the exhaust gas temperature sensor may be considered unreliable, and vice versa. The present invention chooses to obtain the temperature difference threshold based on engine cooling time and to use averaging over the calculation of the temperature difference. Thereby being more accurate in judging the exhaust temperature sensor.
Description
Technical Field
The invention mainly relates to the field of electronic control of diesel engine parts, in particular to a method for diagnosing the credibility of an exhaust temperature sensor.
Background
At present, with the rapid increase of the holding quantity of automobiles, the brought automobile emission pollution is also important. For the current state six emission regulations in practice. The post-processing device is greatly upgraded. In order to accurately control the aftertreatment system and ensure emissions compliance with regulations, an exhaust gas temperature sensor is required to be incorporated into the exhaust system.
Exhaust systems typically have exhaust temperature sensors around: an exhaust gas temperature sensor before DOC (oxidation catalyst), an exhaust gas temperature sensor before DPF (particulate filter), an exhaust gas temperature sensor before SCR (selective catalytic reducer), and an exhaust gas temperature sensor after SCR. So in order to ensure stability and accuracy of the control system, it is necessary to perform a reliability diagnosis for the exhaust gas temperature sensor to determine whether the measured temperature value is reliable.
The existing exhaust temperature sensor is used for diagnosing the reliability, the temperature difference is obtained by using the temperature measured by the exhaust temperature sensor and the selected reference temperature, and whether the temperature of the sensor is reliable or not is judged by the temperature difference and the calibrated temperature difference threshold value. Secondly, the current measured temperature is directly subtracted from the selected reference temperature in the calculation of the temperature difference, and the influence of other factors of the sensor is not considered, so that inaccurate phenomenon can occur in the judgment of the credibility.
Published chinese invention patent, application number CN201910610663.8, patent name: a method and a device for detecting the credibility of a temperature sensor are disclosed, and the application date is as follows: 2019-07-08, the invention relates to a reliability detection method and device of a temperature sensor, wherein the temperature sensor can be a temperature sensor of a urea pump or a temperature sensor of a pump heater. The pump heater may be used to heat the urea pump. The method comprises the following steps: when the urea pump is in a heating mode, i.e. the pump heater heats the urea pump, a measured temperature difference of the temperature sensor may be obtained, wherein the measured temperature difference may be a difference between the temperatures detected by the temperature sensor under actual conditions from time t1 to time t 2. After the measured temperature difference is obtained, a theoretical temperature difference corresponding to the measured temperature difference may also be obtained, where the theoretical temperature difference may be a difference between temperatures from time t1 to time t2 that should be detected by the calculated normal temperature sensor under the actual conditions. Whether the temperature sensor is reliable or not can be determined according to the relation between the measured temperature difference and the theoretical temperature difference.
Disclosure of Invention
The invention provides a method for diagnosing the reliability of an exhaust temperature sensor, which aims at the defects in the prior art and comprises the following steps:
step S1: storing the temperature value measured by the exhaust temperature sensor and the reference temperature into an array after the ECU is electrified;
step S2: judging whether the engine enters an operating state or not when the engine starts, if not, continuously detecting the temperature, and if so, carrying out the next step;
step S3: averaging the temperature value measured by the exhaust gas temperature sensor stored in the array with a reference temperature;
step S4: then taking the difference of the two average values as an absolute value;
step S5: inquiring a calibrated CUR curve by utilizing the cooling time of the engine to obtain a threshold value of the temperature difference;
step S6: if the absolute value of the temperature difference is greater than the threshold value of the obtained temperature difference, the temperature measured by the exhaust gas temperature sensor may be considered unreliable, and vice versa.
Preferably, between steps S2 to S3, the exhaust gas temperature sensor measurement temperature and the reference temperature in the array are frozen, and then the maximum value and the minimum value in the exhaust gas temperature sensor measurement temperature and the reference temperature array are removed as the averaged array of step S3.
Preferably, the reference temperature is selected by an engine temperature array.
Preferably, after step S6, in the case that the temperature measured by the exhaust gas temperature sensor is reliable, the engine enters an operating state and a certain time passes, and the time can be calibrated.
Preferably, the data in step S1 is stored in the array before it is determined whether there is any other failure in the exhaust gas temperature sensor.
Preferably, the temperature value measured by the exhaust gas temperature sensor in step S1 and the reference temperature are stored in two arrays, respectively.
Preferably, in step S5, the engine cooling time first calculates the difference between the current engine temperature and the ambient temperature, and the reference value of the engine cooling time can be obtained by checking the calibrated engine cooling CUR curve through the difference, and the obtained reference value of the engine cooling time needs to be added with an offset to obtain the engine cooling time in consideration of the heat storage effect of the engine component.
The invention has the beneficial effects that: the temperature difference threshold is selected based on the engine cooling time and is obtained by averaging over the calculation of the temperature difference. Thereby being more accurate in judging the exhaust temperature sensor.
Drawings
FIG. 1 is a flow chart of the present invention.
Detailed Description
As shown in fig. 1, the present invention includes the following steps:
step S1: storing the temperature value measured by the exhaust temperature sensor and the reference temperature into an array after the ECU is electrified;
step S2: judging whether the engine enters an operating state or not when the engine starts, if not, continuously detecting the temperature, and if so, carrying out the next step;
step S3: averaging the temperature value measured by the exhaust gas temperature sensor stored in the array with a reference temperature;
step S4: then taking the difference of the two average values as an absolute value;
step S5: inquiring a calibrated CUR curve by utilizing the cooling time of the engine to obtain a threshold value of the temperature difference;
step S6: if the absolute value of the temperature difference is greater than the threshold value of the obtained temperature difference, the temperature measured by the exhaust gas temperature sensor may be considered unreliable, and vice versa.
In use, the present invention addresses the problems of the prior art by selecting to obtain a temperature difference threshold based on engine cooling time and averaging the temperature difference calculations to provide more accuracy in determining the exhaust gas temperature sensor
In this embodiment, it is preferable that between steps S2 to S3, the exhaust gas temperature sensor measurement temperature and the reference temperature in the array are frozen, and then the maximum value and the minimum value in the exhaust gas temperature sensor measurement temperature and the reference temperature array are removed as the averaged array of step S3.
By setting the structure, the maximum value and the minimum value are removed, extreme data are avoided, stable data are obtained, and the diagnosis result is more reliable.
In this embodiment, the reference temperature is preferably selected by an engine temperature array.
With the above configuration, the selection of the reference temperature can be made by the engine temperature array, such as the coolant temperature.
In this embodiment, preferably, after step S6, when the temperature measured by the exhaust gas temperature sensor is reliable, the engine is put into operation and a certain time elapses, and the time can be calibrated.
In this embodiment, it is preferable that the data in step S1 is required to determine whether there is another failure in the exhaust gas temperature sensor before being stored in the array.
With the above structure, the two temperature values stored in the array are firstly ensured to be effective before the average value of the measured temperature and the reference temperature of the exhaust gas temperature sensor is calculated, that is, whether other faults (signal faults or electric faults) exist in the exhaust gas temperature sensor is required to be judged before the exhaust gas temperature sensor is stored in the array.
In this embodiment, the temperature value measured by the exhaust gas temperature sensor in step S1 and the reference temperature are stored in two arrays, respectively.
By setting the structure, two temperatures are respectively stored in two arrays, and the number of the two temperatures can be specifically calibrated.
In this embodiment, preferably, in step S5, the engine cooling time first calculates the difference between the current engine temperature and the ambient temperature, and the reference value of the engine cooling time can be obtained by checking the calibrated engine cooling CUR curve according to the difference, and considering the heat storage effect of the engine component, the obtained engine cooling time reference value needs to be added with an offset to obtain the engine cooling time.
The above-described embodiments are merely illustrative of the principles of the present application and their effectiveness, and are not intended to limit the present application. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present application. Accordingly, it is intended that all equivalent modifications and variations which may be accomplished by those skilled in the art without departing from the spirit and technical spirit of the present invention shall be covered by the claims of this patent application.
Claims (7)
1. A method for diagnosing the reliability of an exhaust gas temperature sensor, comprising the steps of:
step S1: storing the temperature value measured by the exhaust temperature sensor and the reference temperature into an array after the ECU is electrified;
step S2: judging whether the engine enters an operating state or not when the engine starts, if not, continuously detecting the temperature, and if so, carrying out the next step;
step S3: averaging the temperature value measured by the exhaust gas temperature sensor stored in the array with a reference temperature;
step S4: then taking the difference of the two average values as an absolute value;
step S5: inquiring a calibrated CUR curve by utilizing the cooling time of the engine to obtain a threshold value of the temperature difference;
step S6: if the absolute value of the temperature difference is greater than the threshold value of the obtained temperature difference, the temperature measured by the exhaust gas temperature sensor may be considered unreliable, and vice versa.
2. The method of exhaust gas temperature sensor reliability diagnosis according to claim 1, characterized in that: and between the steps S2 and S3, freezing the measured temperature and the reference temperature of the exhaust gas temperature sensor in the array, and then removing the maximum value and the minimum value in the array of the measured temperature and the reference temperature of the exhaust gas temperature sensor as the average value array of the step S3.
3. The method of exhaust gas temperature sensor reliability diagnosis according to claim 2, characterized in that: the reference temperature is selected by an engine temperature array.
4. A method of exhaust gas temperature sensor plausibility diagnosis according to claim 3, characterized in that: after the step S6, under the condition that the temperature measured by the exhaust temperature sensor is reliable, the engine enters the running state and a certain time passes, and the time can be calibrated.
5. The method of exhaust gas temperature sensor reliability diagnosis according to claim 4, characterized in that: before the data in the step S1 is stored in the array, it is required to determine whether there are other faults in the exhaust temperature sensor.
6. The method of exhaust gas temperature sensor reliability diagnosis according to claim 5, characterized in that: the temperature value measured by the exhaust gas temperature sensor in the step S1 and the reference temperature are respectively stored in two arrays.
7. The method of exhaust gas temperature sensor reliability diagnosis according to claim 6, characterized in that: in the step S5, the engine cooling time first calculates the difference between the current engine temperature and the ambient temperature, and the calibrated engine cooling CUR curve is checked by the difference to obtain the reference value of the engine cooling time, and the obtained reference value of the engine cooling time is added with an offset to obtain the engine cooling time by considering the heat storage effect of the engine component.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001349864A (en) * | 2000-06-07 | 2001-12-21 | Mitsubishi Electric Corp | Temperature detection device for exhaust gas sensor |
| JP2013108405A (en) * | 2011-11-18 | 2013-06-06 | Isuzu Motors Ltd | Internal combustion engine and failure diagnosis method for temperature sensor thereof |
| CN107503854A (en) * | 2017-09-29 | 2017-12-22 | 北京理工大学 | Determine supercharged diesel engine exhaust gas temperature sensor whether exception and method for diagnosing faults |
| CN110094274A (en) * | 2018-01-30 | 2019-08-06 | 福特全球技术公司 | Environment temperature sensor reasonableness check |
| CN110094273A (en) * | 2018-01-30 | 2019-08-06 | 福特全球技术公司 | Environment temperature sensor reasonableness check |
| CN110107389A (en) * | 2019-07-08 | 2019-08-09 | 潍柴动力股份有限公司 | A kind of creditability detection method and device of temperature sensor |
| CN110715755A (en) * | 2019-09-19 | 2020-01-21 | 潍柴动力股份有限公司 | Temperature sensor fault diagnosis method and diagnosis system |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4166354B2 (en) * | 1999-02-09 | 2008-10-15 | 本田技研工業株式会社 | Temperature sensor failure diagnosis device |
| JP3565800B2 (en) * | 2001-07-05 | 2004-09-15 | 本田技研工業株式会社 | Temperature sensor failure judgment device |
| JP4105086B2 (en) * | 2003-12-22 | 2008-06-18 | 本田技研工業株式会社 | Temperature sensor failure diagnosis device |
| DE102005023276B4 (en) * | 2005-05-20 | 2017-01-05 | Zf Friedrichshafen Ag | Method for determining the initial values for a temperature estimation method of components of a motor vehicle |
| JP5294446B2 (en) * | 2008-02-08 | 2013-09-18 | ボッシュ株式会社 | Temperature sensor rationality diagnostic device, rationality diagnostic method, and exhaust purification device for internal combustion engine |
| JP5531776B2 (en) * | 2010-05-24 | 2014-06-25 | 日産自動車株式会社 | Temperature sensor failure diagnosis device |
| DE102011002502B4 (en) * | 2010-08-02 | 2023-06-07 | Robert Bosch Gmbh | Method for diagnosing an exhaust gas sensor and device for carrying out the method |
| JP6213255B2 (en) * | 2014-01-20 | 2017-10-18 | 株式会社デンソー | Temperature sensor abnormality diagnosis apparatus and abnormality diagnosis method |
| CN104100341A (en) * | 2014-06-30 | 2014-10-15 | 潍柴动力股份有限公司 | DPF (Diesel Particulate Filter) self-diagnosis device, self-diagnosis method and engine tail gas treatment system |
| CN105628257B (en) * | 2015-12-18 | 2018-08-31 | 潍柴动力股份有限公司 | A kind of detection method and device of exhaust gas temperature sensor failure |
| JP6804941B2 (en) * | 2016-11-09 | 2020-12-23 | 日本碍子株式会社 | Method of suppressing output deterioration of hybrid potential type gas sensor |
| CN110700925B (en) * | 2018-07-09 | 2022-07-05 | 卓品智能科技无锡有限公司 | Vehicle-mounted nitrogen-oxygen sensor fault rate online counting and correcting method |
| CN109297618A (en) * | 2018-09-30 | 2019-02-01 | 潍柴动力股份有限公司 | A kind of method and device detecting insincere property |
-
2020
- 2020-06-11 CN CN202010529854.4A patent/CN113803140B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001349864A (en) * | 2000-06-07 | 2001-12-21 | Mitsubishi Electric Corp | Temperature detection device for exhaust gas sensor |
| JP2013108405A (en) * | 2011-11-18 | 2013-06-06 | Isuzu Motors Ltd | Internal combustion engine and failure diagnosis method for temperature sensor thereof |
| CN107503854A (en) * | 2017-09-29 | 2017-12-22 | 北京理工大学 | Determine supercharged diesel engine exhaust gas temperature sensor whether exception and method for diagnosing faults |
| CN110094274A (en) * | 2018-01-30 | 2019-08-06 | 福特全球技术公司 | Environment temperature sensor reasonableness check |
| CN110094273A (en) * | 2018-01-30 | 2019-08-06 | 福特全球技术公司 | Environment temperature sensor reasonableness check |
| CN110107389A (en) * | 2019-07-08 | 2019-08-09 | 潍柴动力股份有限公司 | A kind of creditability detection method and device of temperature sensor |
| CN110715755A (en) * | 2019-09-19 | 2020-01-21 | 潍柴动力股份有限公司 | Temperature sensor fault diagnosis method and diagnosis system |
Non-Patent Citations (1)
| Title |
|---|
| 电控发动机中温度传感技术;姜水生;《小型内燃机》;全文 * |
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