EP2697487A1 - Procédé pour faire fonctionner une sonde lambda - Google Patents

Procédé pour faire fonctionner une sonde lambda

Info

Publication number
EP2697487A1
EP2697487A1 EP11794047.8A EP11794047A EP2697487A1 EP 2697487 A1 EP2697487 A1 EP 2697487A1 EP 11794047 A EP11794047 A EP 11794047A EP 2697487 A1 EP2697487 A1 EP 2697487A1
Authority
EP
European Patent Office
Prior art keywords
temperature
lambda probe
resistance
operating
measured
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11794047.8A
Other languages
German (de)
English (en)
Inventor
Martin Grillenberger
Jörg Merkel
Björn SPECHT
Andreas Zimmermann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mercedes Benz Group AG
Original Assignee
Daimler AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daimler AG filed Critical Daimler AG
Publication of EP2697487A1 publication Critical patent/EP2697487A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/4067—Means for heating or controlling the temperature of the solid electrolyte
    • 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
    • F01N11/007—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
    • 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
    • F01N2560/02—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor
    • F01N2560/025—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor for measuring or detecting O2, e.g. lambda sensors
    • 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

Definitions

  • the invention relates to a method for operating a lambda probe after
  • Lambda sensors are probes for determining the residual oxygen content in the exhaust gas of a motor vehicle. They include a so-called Nernst cell with a zirconium membrane, which is lapped by the exhaust gas flow on one side and with the
  • lambda probes with zirconium membranes have to be heated to temperatures of more than 650 ° C.
  • resistance heaters are usually provided. Since the membrane potential of the lambda probe is also dependent on the temperature, it must be precisely controlled during operation of the lambda probe. Usually, no separate temperature sensors are provided for this purpose; instead, the temperature-dependent resistance of the Nernst cell is used as the temperature measure.
  • the zirconium membrane shows the behavior of a resistor with negative temperature coefficients, so it becomes more conductive with increasing temperature. The ideal working temperature of the probe thus corresponds to a certain resistance value via the Nernst cell, so that regulation of the heating of the lambda probe can be carried out on the basis of the resistance measurement.
  • a conventional method for operating a lambda probe in the manner described is known, for example, from DE 10 2004 057 929 A1.
  • the present invention is based on the object to provide a method for operating a lambda probe, which allows a reliable temperature control of the probe even at higher maturities.
  • a resistance of a Nernst cell of the lambda probe is measured in a first operating mode and a temperature of the lambda probe is determined on the basis of the measured resistance.
  • a heating voltage of a heater of the lambda probe is set as a function of a difference between the measured temperature and a target temperature, so that it can be ensured that the lambda probe is always operated at the optimum temperature.
  • the lambda probe in a second operating mode, is operated at a predetermined temperature and is measured during operation at the predetermined temperature, the resistance of the Nernst cell. From the difference of the measured resistance to a predetermined setpoint resistance, a correction factor for determining the temperature of the lambda probe in the first operating mode is determined.
  • the second operating mode thus represents a calibration mode for the lambda probe.
  • the predetermined temperature is set by operating the heater with a predetermined heating voltage.
  • a predetermined heating voltage This is a particularly simple and convenient way, since the heater shows no signs of aging in contrast to the Nernst cell. Even with aged lambda probes, therefore, there is always a known relationship between the predetermined heating voltage and the temperature achieved thereby at the heating device.
  • the predetermined heating voltage is varied after installation of a new lambda probe until the resistance of the Nernst cell reaches the setpoint resistance.
  • the heating voltage for the second operating mode is indirectly determined experimentally from the known resistance-temperature relationship of a new lambda probe, at which point the lambda probe reaches the desired setpoint temperature.
  • the second operating state is taken at regular time intervals. This can for example be done after each start of the motor vehicle or coupled to the service cycle of the motor vehicle. This ensures that aging phenomena of the lambda probe are detected early, so that a corresponding correction factor can be determined.
  • the second operating state is only assumed if at least one operating and / or environmental parameter of the motor vehicle lies within a predetermined value range.
  • operational and / or environmental parameters are expediently selected, which likewise have an influence on the temperature of the lambda probe, so that the determination of the correction factor in the second operating mode is not falsified by these parameters.
  • a correction factor is determined in the second operating mode only if the difference between the measured resistance of the Nernst cell and the setpoint resistance exceeds a predetermined threshold value. This avoids that complex corrections have to be carried out in each case with small fluctuations in the resistance-temperature relationship of the Nernst cell.
  • the measured resistance of the Nernst cell is preferably stored in a memory device each time the motor vehicle is operated in the second operating mode.
  • the aging behavior of the lambda probe can be determined particularly well over the course over time of the resistors thus determined at a given temperature. It is possible to read these values, for example during service processes, in order to collect a large amount of data about the aging behavior of the lambda probes under real operating conditions and to evaluate them for an entire vehicle fleet.
  • Fig. 1 is a schematic representation of a lambda probe
  • Fig. 3 is a graphical representation of the dependence between temperature of a
  • Fig. 4 shows the time course of the resistance of Nernstzellen different
  • FIG. 5 shows a control loop for regulating the temperature of a lambda probe when using an embodiment of a method according to the invention
  • FIG. 6 shows a schematic representation of the method steps in the determination of a correction factor for the temperature control of a lambda probe in the context of an exemplary embodiment of a method according to the invention
  • FIG. 7 shows a control loop for temperature control of a lambda probe.
  • a lambda probe shown generally at 10 in FIG. 1 for determining the oxygen content in an exhaust gas of a motor vehicle, comprises a membrane 12 made of zirconium (IV) oxide which is bounded on both sides by gas-permeable platinum electrodes 14, 16. On the side of the electrode 14, the lambda probe 10 is at a
  • Exhaust gas stream 18 of the motor vehicle in conjunction, on the side of the electrode 16 with the outside air 20.
  • oxygen can diffuse through the zirconium membrane 12.
  • Lambda probe 10 on which there is a relative excess of oxygen, the molecular oxygen absorbs electrons from the respective electrode 14, 16 and diffuses in the form of 0 2 " ions through the zirconium membrane 12. Between the electrodes 14, 16 therefore sets a potential difference , which can be determined by means of a voltage measuring device 22. From the potential difference between the two sides of the lambda probe 10, the ratio of the oxygen partial pressure in the exhaust gas flow to the oxygen partial pressure in the ambient air 20 can be determined. Further, to bring the diaphragm 12 to its desired temperature, heating elements 24 are provided intended. The regulation of the heating elements 24 and thus the temperature of the lambda probe 10 is carried out according to the prior art according to a control loop, as shown in Fig. 2. To determine the temperature of the lambda probe 10, the resistance of the Nernst cell, ie the zirconium membrane 12 with its electrodes 14, 16, is used. It depends on the temperature and, as shown in FIG. 2. To determine the temperature of the lambda probe 10, the resistance of the N
  • the resistance of the Nernst cell is first determined and converted in a further step according to the characteristic curve from FIG. 3 into a temperature of the lambda probe 10. By difference between the measured temperature and a predetermined setpoint temperature becomes a
  • the relationship between the temperature of the Nernst cell and its resistance varies with the age of the lambda probe 10.
  • the drawn in Fig. 3 and marked with squares line 26 shows the relationship between temperature and resistance of the Nernst cell for a new lambda probe, the solid line 28 those for an aged lambda probe 10.
  • the resistance of the Nernst cell is approximately 80 ohms. If the control according to FIG. 2 is continued unchanged even with an aged lambda probe 10, the aged lambda probe 10 is also regulated to a Nernst resistance of 80 ohms.
  • the aged lambda probe 10 has a significantly elevated temperature of more than 950 ° C with a Nernst resistance of 80 ohms. This can falsify the measurement results of the lambda probe and possibly lead to damage to the ceramic body.
  • FIG. 4 shows the change in the Nernst resistance of the lambda probe 10 at a predetermined operating temperature as a function of the number of operating hours in a plurality of measurement series. It can be clearly seen that this results in significant and strong shifts that can lead to temperature deviations of several hundred degrees in a temperature-resistance curve according to FIG. 3, if only regulated to a fixed predetermined resistance of the Nernst cell of the lambda probe 10 out.
  • a differential measurement is performed on a newly installed lambda probe 10.
  • a reference heating voltage is determined at which the lambda probe 10 reaches a predetermined temperature. This can be done, for example, by varying
  • the temperature measurement can also be omitted and replaced by simple resistance measurement, since the relationship between Nernstwiderstand and probe temperature is also known.
  • the thus determined reference heating voltage, at which the lambda probe 10 reaches exactly the desired temperature is subsequently stored in a memory device, for example an EEPROM of the motor vehicle, as a reference variable.
  • this reference heating voltage can be used for targeted adjustment of the lambda probe temperature, since the heating elements, in contrast to the Nernst cell, have no signs of aging.
  • the temperature of the lambda probe 10 is influenced not only by the heating voltage at the heating elements 24, but also by other environmental factors. These include the ambient temperature itself and the temperature of the exhaust line, which in turn is influenced by operating variables of the motor vehicle such as a coolant temperature, an injection quantity, an engine speed, an exhaust gas mass flow, possibly the presence of a regeneration operation or the like. If the setpoint temperature of the lambda probe is later to be set for a calibration measurement using the stored reference heating voltage, care must be taken to ensure that these influencing variables are within specified limits, so that the calibration is not falsified.
  • a calibration according to FIG. 6 is then carried out at regular intervals. For this purpose, if the mentioned environmental parameters are within their desired value range, the stored reference heating voltage is applied to the heating elements 24. As a result, the temperature of the lambda probe is reliably set to its desired value. Now, the resistance can be measured via the zirconium diaphragm 12, so that the Nernstwiderstand the lambda probe 10 at their
  • a compensation factor is determined, which is included in the conversion between the measured Nernst resistance and the existing probe temperature.
  • the further control is carried out as known, in which an integral controller receives the difference between the measured and corrected by means of the compensation factor probe temperature and the setpoint temperature as an input and provides the output necessary for the temperature adjustment voltage for the heating elements 24 as an output. In this way it can be ensured that the desired setpoint temperature is maintained at all times even in the case of aged lambda sensors, without resulting in possibly harmful overheating of the lambda probe 10.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Biochemistry (AREA)
  • Pathology (AREA)
  • Analytical Chemistry (AREA)
  • Electrochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Physics & Mathematics (AREA)
  • Molecular Biology (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Measuring Oxygen Concentration In Cells (AREA)

Abstract

L'invention concerne un procédé pour faire fonctionner une sonde lambda (10), selon lequel, dans un premier mode de fonctionnement, une résistance d'une cellule de Nernst (12) de la sonde lambda (10) est mesurée et, sur la base de la résistance mesurée, une température de la sonde lambda (10) est déterminée, une tension de chauffage d'un dispositif de chauffage (24) de la sonde lambda (10) étant réglée en fonction de l'écart entre la température mesurée et une température de consigne. Selon l'invention, dans un deuxième mode de fonctionnement, la sonde lambda (10) fonctionne à une température prédéfinie et, pendant que ladite sonde fonctionne à la température prédéfinie, la résistance de la cellule de Nernst (12) est mesurée, un facteur de correction étant défini à partir de l'écart entre la résistance mesurée et une résistance de consigne prédéfinie, lequel facteur permet de déterminer la température de la sonde lambda (10) dans le premier mode de fonctionnement.
EP11794047.8A 2011-04-14 2011-12-07 Procédé pour faire fonctionner une sonde lambda Withdrawn EP2697487A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102011017015.4A DE102011017015B4 (de) 2011-04-14 2011-04-14 Verfahren zum Betreiben einer Lambdasonde
PCT/EP2011/006124 WO2012139608A1 (fr) 2011-04-14 2011-12-07 Procédé pour faire fonctionner une sonde lambda

Publications (1)

Publication Number Publication Date
EP2697487A1 true EP2697487A1 (fr) 2014-02-19

Family

ID=45315724

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11794047.8A Withdrawn EP2697487A1 (fr) 2011-04-14 2011-12-07 Procédé pour faire fonctionner une sonde lambda

Country Status (3)

Country Link
EP (1) EP2697487A1 (fr)
DE (1) DE102011017015B4 (fr)
WO (1) WO2012139608A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102013216595A1 (de) 2013-08-21 2015-02-26 Robert Bosch Gmbh Verfahren und Vorrichtung zur Korrektur einer Kennlinie einer Lambdasonde
DE102015003764A1 (de) 2015-03-24 2015-12-03 Daimler Ag Verfahren zum Betreiben einer Lambdasonde eines Fahrzeugs

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4344961B4 (de) 1993-12-30 2004-05-06 Robert Bosch Gmbh Auswertevorrichtung für das Signal einer Sauerstoffsonde
JP3833467B2 (ja) 2000-11-22 2006-10-11 三菱電機株式会社 排ガスセンサの劣化検出装置
JP3744486B2 (ja) 2002-11-25 2006-02-08 トヨタ自動車株式会社 酸素センサの劣化検出装置
DE102004057929B4 (de) 2004-12-01 2006-09-14 Daimlerchrysler Ag Verfahren zum Betrieb einer Brennkraftmaschine eines Kraftfahrzeugs
JP4645984B2 (ja) 2005-07-05 2011-03-09 株式会社デンソー 排出ガスセンサの劣化検出装置
DE102008005110B4 (de) 2008-01-15 2018-10-25 Volkswagen Ag Verfahren und Steuerung zum Betreiben und Einstellen einer Lambda-Sonde
DE102009053411A1 (de) 2009-11-14 2011-05-19 Volkswagen Ag Verfahren zum Verarbeiten eines gemessenen, ohmschen Widerstandes R(t) eines Messelementes mit temperaturabhängigem, ohmschen Widerstand
DE102010041421A1 (de) 2010-09-27 2012-03-29 Robert Bosch Gmbh Verfahren zum Betrieb eines Sensorelements

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2012139608A1 *

Also Published As

Publication number Publication date
DE102011017015A1 (de) 2012-10-18
WO2012139608A1 (fr) 2012-10-18
DE102011017015B4 (de) 2023-09-21

Similar Documents

Publication Publication Date Title
DE102006011837B4 (de) Verfahren zur Ermittlung einer Gaskonzentration in einem Messgas mit einem Gassensor
DE102015205971B4 (de) Verfahren zum Betreiben einer Sonde
WO2006069879A1 (fr) Procede pour surveiller le fonctionnement d'un capteur
DE102012211687A1 (de) Verfahren und Steuereinheit zur Erkennung eines Spannungsoffsets einer Spannungs-Lambda-Kennlinie
EP3596453B1 (fr) Procédé de fonctionnement d'un capteur de détection d'au moins une propriété d'un gaz à mesurer dans un espace de gaz à mesurer
EP2580584B1 (fr) Méthode pour identifier le type de sonde lambda
DE102015206867A1 (de) Verfahren zum Betreiben eines Sensors zur Erfassung mindestens einer Eigenschaft eines Messgases in einem Messgasraum
EP2725350A2 (fr) Procédé de détection de gaz et dispositif de détection de gaz correspondant
DE102012200592A1 (de) Verfahren und Vorrichtung zur Ermittlung eines Zustands eines Sensors
EP2271920B1 (fr) Circuit de commande pour capteur de gaz électrochimique et procédé de réglage d'un tel capteur de gaz électrochimique
EP2612137A1 (fr) Procédé et dispositif pour détecter au moins une propriété d'un gaz
EP1075657A1 (fr) PROCEDE POUR LA DETERMINATION DE LA CONCENTRATION EN NO x?
DE102011017015B4 (de) Verfahren zum Betreiben einer Lambdasonde
EP2322916B1 (fr) Procédé de traitement d'une résistance ohmique mesurée R(t) d'un élément de mesure doté d'une résistance ohmique dépendant de la température
DE102010039188A1 (de) Verfahren zur Erfassung einer Eigenschaft eines Gases in einem Messgasraum
EP1084399B1 (fr) Procede pour la determination de la concentration en nox
WO2012079934A9 (fr) Procédé de détection de la capacité à fonctionner d'une sonde lambda à saut de tension
DE102008011834A1 (de) Verfahren zum Betreiben einer Lambdasonde
WO2020011652A1 (fr) Procédé destiné à faire fonctionner un capteur électrochimique à base d'électrolyte solide
DE102014016952A1 (de) Verfahren zum Betreiben einer Lambda-Sonde eines Abgassystems eines Kraftfahrzeugs
DE102010002458A1 (de) Abgassonde
DE102013212288A1 (de) Verfahren zum Betrieb eines Sensorelements und Sensorvorrichtung
WO2012034761A1 (fr) Procédé de détermination d'une propriété d'un gaz dans une chambre de gaz de mesure
DE102012200026A1 (de) Verfahren und Vorrichtung zur Ermittlung einer Konzentration mindestens einer Gaskomponente im Abgas einer Brennkraftmaschine mittels eines Sensorelements sowie zur Ermittlung einer Temperatur des Sensorelements
DE102014224942A1 (de) Verfahren zur Erkennung eines Zustands eines Heizelements in einem Sensor

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20130705

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

RIN1 Information on inventor provided before grant (corrected)

Inventor name: SPECHT, BJOERN

Inventor name: ZIMMERMANN, ANDREAS

Inventor name: GRILLENBERGER, MARTIN

Inventor name: MERKEL, JOERG

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20160315

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20180302