EP0616119B1 - Method for monitoring a lambda sensor - Google Patents

Method for monitoring a lambda sensor Download PDF

Info

Publication number
EP0616119B1
EP0616119B1 EP93104163A EP93104163A EP0616119B1 EP 0616119 B1 EP0616119 B1 EP 0616119B1 EP 93104163 A EP93104163 A EP 93104163A EP 93104163 A EP93104163 A EP 93104163A EP 0616119 B1 EP0616119 B1 EP 0616119B1
Authority
EP
European Patent Office
Prior art keywords
value
lean
rich
probe signal
probe
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.)
Expired - Lifetime
Application number
EP93104163A
Other languages
German (de)
French (fr)
Other versions
EP0616119A1 (en
Inventor
Erwin Dr. Dipl.-Ing. Achleitner
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.)
Siemens AG
Original Assignee
Siemens 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 Siemens AG filed Critical Siemens AG
Priority to EP93104163A priority Critical patent/EP0616119B1/en
Priority to DE59306790T priority patent/DE59306790D1/en
Priority to JP6068945A priority patent/JPH06273281A/en
Priority to US08/212,972 priority patent/US5488858A/en
Publication of EP0616119A1 publication Critical patent/EP0616119A1/en
Application granted granted Critical
Publication of EP0616119B1 publication Critical patent/EP0616119B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1493—Details
    • F02D41/1495—Detection of abnormalities in the air/fuel ratio feedback system
    • 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
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1473—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation method
    • F02D41/1474—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation method by detecting the commutation time of the sensor

Definitions

  • the invention relates to a method for checking the functionality of lambda probes, in which the switching times of the lambda probe are measured.
  • pollutant emissions can be reduced by catalytic aftertreatment.
  • the catalytic after-treatment requires a certain composition of the exhaust gas, a so-called stoichiometric mixture.
  • a mixture control by means of a so-called lambda probe is used for this, by means of which the mixture composition is periodically regulated within narrow limits around the setpoint.
  • the probes can become defective in the course of operation, the mixture composition is subsequently incorrectly regulated, the exhaust gases are no longer properly detoxified and even the catalyst is damaged in the long run.
  • the object of the present invention is therefore to specify a method which allows the dynamic functionality of the lambda probe to be checked reliably.
  • the lambda sensor outputs a higher voltage value for a rich mixture than for a lean mixture.
  • the method according to the invention functions in an analogous manner also with lambda probes which have an opposite voltage / mixture assignment.
  • a reference value is determined from the switching times of the lambda probe; here, in the exemplary embodiment, a plurality of switching times are added up, with a separate evaluation of the switching times from rich to lean and takes place from lean to rich, and compared with an assigned limit value.
  • step S1 the switching time TS is measured, which the lambda probe requires for a switch from rich to lean or from lean to rich.
  • the measurement is carried out, for example, with a clocked time counter.
  • the duration counter remains at zero as long as the lambda sensor signal is above the fat threshold. If it drops below the fat threshold, the time counter starts to run. It stops again when the lambda sensor signal has dropped below the lean threshold.
  • the time counter remains at zero as long as the lambda sensor signal is below the lean threshold. If it rises above the lean threshold, the time counter starts to run. It stops again when the lambda probe signal rises above the fat threshold.
  • a predeterminable fraction of the maximum value of the lambda probe signal is defined as the fat and lean threshold. For example, 90% of the maximum value is assumed as the fat threshold and 10% of the maximum value as the lean threshold. Instead of the last measured individual maximum value or minimum value, the value determined by means of a sliding averaging from the respective last actually measured values can also be used.
  • step S2 the switching process is checked for reversal points.
  • a reversal point occurs when the lambda sensor signal, which is actually steadily decreasing, suddenly becomes larger again in the switching process from rich to lean, or in the switching process from lean to rich, the lambda sensor signal, which is actually steadily increasing, suddenly becomes smaller again. If such a reversal point is recognized, this switching time is not used for evaluation.
  • step S3 it is checked whether the internal combustion engine is in an approximately stationary state, i.e. whether the load and speed have not changed significantly since the last switching time measurement. If there is no such approximately stationary state, the switching time is also not used for evaluation.
  • step S5 the currently determined switching time TS is added to the total SFM of the switching times already determined. Then, in step S6, the switching time limit value FMG is read out from a map as a function of, for example, the air mass sucked in and the speed of the internal combustion engine and is added to the sum SFMG of the limit values already read out.
  • the counter ZF which indicates the number of changes from rich to lean, is increased by one.
  • method step S8 it is checked whether the value of the counter ZF is smaller than a predefinable trigger value ZFA, which determines the size of the test cycle. If this is the case, the process branches back to the beginning of the procedure. However, if the value is equal to or greater than the trigger value, a check is carried out in method step S14 as to whether the sum of the switching times SFM determined from rich to lean is less than the limit value SFMG. If this is the case, it is indicated in method step S16 that the lambda probe is OK. If the total value SFM determined is equal to or greater than that Limit value SFMG, it is indicated in method step S15 that the lambda probe is defective. In both cases, the counters and summands are reset in method step S17 and then, if the lambda probe is to be checked again, the method is returned to the beginning of the method.
  • a predefinable trigger value ZFA which determines the size of the test cycle.
  • step S9 the currently determined switching time TS is added to the sum SMF of the switching times already determined.
  • step S10 the switching time limit value MFG is read out again from a map as a function of the current operating conditions of the internal combustion engine (for example on the basis of the intake air mass and the current speed) and added to the sum SMFG of the limit values already read out.
  • step S11 the counter ZM, which indicates the number of changes from rich to lean, is increased by one.
  • step S12 it is checked whether the value of the counter ZM is less than a trigger value ZMA. If this is the case, the process is returned to the beginning of the procedure. If, however, the value is equal to or greater than the triggering value, it is checked in method step S13 whether the sum of the determined switching times SMF from lean to rich is less than the limit value SMFG. If this is the case, as already described above, step S16 indicates that the lambda probe is OK. If, however, the total value is equal to or greater than the limit value, it is indicated in method step S15 that the lambda probe is defective, as also described above is. If the lambda probe is defective, any existing catalyst efficiency check is blocked.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Testing Of Engines (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Description

Die Erfindung betrifft ein Verfahren zur Überprüfung der Funktionsfähigkeit von Lambdasonden, bei dem die Schaltzeiten der Lambdasonde gemessen werden.The invention relates to a method for checking the functionality of lambda probes, in which the switching times of the lambda probe are measured.

Bei Brennkraftmaschinen können die Schadstoffemissionen durch katalytische Nachbehandlung vermindert werden.In internal combustion engines, pollutant emissions can be reduced by catalytic aftertreatment.

Die katalytische Nachbehandlung setzt eine bestimmte Zusammensetzung des Abgases voraus, ein sogenanntes stöchiometrisches Gemisch. Hierzu dient eine Gemischregelung mittels einer sogenannten Lambdasonde, durch die die Gemischzusammensetzung periodisch in engen Grenzen um den Sollwert reguliert wird. Diese Sonde gibt dazu bei fettem Kraftstoff/Luftgemisch eine große Spannung (die Fettspannung) und bei magerem Kraftstoff-/Luftgemisch eine kleine Spannung ab; dazwischen liegt ein Spannungssprung , der für λ = 1 charakteristisch ist.The catalytic after-treatment requires a certain composition of the exhaust gas, a so-called stoichiometric mixture. A mixture control by means of a so-called lambda probe is used for this, by means of which the mixture composition is periodically regulated within narrow limits around the setpoint. For this purpose, this probe emits a large voltage (the rich voltage) when the fuel / air mixture is rich and a small voltage when the fuel / air mixture is lean; in between is a voltage jump that is characteristic of λ = 1.

Die Sonden können im Laufe des Betriebes defekt werden, die Gemischzusammensetzung wird in Folge falsch geregelt, die Abgase werden nicht mehr korrekt entgiftet und auf Dauer wird dann sogar der Katalysator beschädigt.The probes can become defective in the course of operation, the mixture composition is subsequently incorrectly regulated, the exhaust gases are no longer properly detoxified and even the catalyst is damaged in the long run.

Es ist deswegen notwendig, die Funktionsfähigkeit der Lambdasonde zu überwachen.It is therefore necessary to monitor the functionality of the lambda probe.

Aus US-A-3,938,075 ist ein Verfahren zur Überwachung einer Lambdasonde bekannt, wobei bei Arbeitsbedingungen des Lambdaregelkreises die Schaltzeit festgestellt wird, in der das Sondensignal sich von einem Fettwert auf einen Magerwert oder von dem Magerwert auf den Fettwert ändert und die Sonde als korrekt arbeitend eingestuft wird, wenn diese Zeit kleiner als ein Grenzwert ist.From US-A-3,938,075 a method for monitoring a lambda probe is known, the switching time being determined under working conditions of the lambda control loop, in which the probe signal changes from a rich value to a lean value or from the lean value to the rich value and the probe works correctly is classified if this time is less than a limit value.

Aus US-A-4,177,787 ist ein Verfahren zur Überwachung einer Lambdasonde bekannt, bei der die Schaltzeit von Fett nach Mager und die Schaltzeit von Mager nach Fett unterschiedlich sind und getrennt oder im Verhältnis zueinander für den Nachweis einer fehlerhaften Lambdasonde verwendet werden.From US-A-4,177,787 a method for monitoring a lambda probe is known in which the switching time from rich to lean and the switching time from lean to rich are different and are used separately or in relation to one another for the detection of a defective lambda probe.

Aufgabe der vorliegenden Erfindung ist es daher, ein Verfahren anzugeben, das es gestattet, die dynamische Funktionsfähigkeit der Lambdasonde zuverlässig zu überprüfen.The object of the present invention is therefore to specify a method which allows the dynamic functionality of the lambda probe to be checked reliably.

Gelöst wird dies, mit den Merkmalen gemäß Anspruch 1.This is solved with the features according to claim 1.

Zur Überprüfung der Schaltzeiten ist es notwendig, daß sich die Brennkraftmaschine während des Prüfzykluses in einem annähernd stationären Betriebszustand befindet. In diesem Zustand ist die Prüfung aber dann möglich, ohne in die Lambda-Regelung störend einzugreifen.To check the switching times, it is necessary for the internal combustion engine to be in an approximately stationary operating state during the test cycle. In this state, however, the test is then possible without interfering with the lambda control.

Das Verfahren wird im folgenden anhand der Zeichnung noch näher erläutert. Die Zeichnung zeigt schematisch den Ablauf eines Ausführungsbeispiels des erfindungsgemäßen Verfahrens.The method is explained in more detail below with reference to the drawing. The drawing shows schematically the sequence of an embodiment of the method according to the invention.

Bei diesem Ausführungsbeispiel wird angenommen, daß die Lambdasonde bei einem fettem Gemisch einen höheren Spannungswert ausgibt als bei einem mageren Gemisch. Das erfindungsgemäße Verfahren funktioniert in analoger Weise auch bei Lambdasonden, die eine entgegengesetzte Spannungs- / Gemischzuordnung aufweisen.In this exemplary embodiment, it is assumed that the lambda sensor outputs a higher voltage value for a rich mixture than for a lean mixture. The method according to the invention functions in an analogous manner also with lambda probes which have an opposite voltage / mixture assignment.

Erfindungsgemäß wird aus den Schaltzeiten der Lambdasonde ein Bezugswert (BW) ermittelt, hier im Ausführungsbeispiel werden dazu mehrere Schaltzeiten aufsummiert, wobei eine getrennte Auswertung der Schaltzeiten von Fett nach Mager und von Mager nach Fett erfolgt, und mit einem zugeordneten Grenzwert verglichen.According to the invention, a reference value (BW) is determined from the switching times of the lambda probe; here, in the exemplary embodiment, a plurality of switching times are added up, with a separate evaluation of the switching times from rich to lean and takes place from lean to rich, and compared with an assigned limit value.

Im Verfahrensschritt S1 wird die Schaltzeit TS gemessen, die die Lambdasonde für eine Umschaltung von fett nach mager oder von mager nach fett benötigt.
Die Messung erfolgt beispielsweise mit einem getakteten Zeitzähler. Bei der Umschaltung von fett nach mager bleibt der Zeitdauerzähler auf Null, solange sich das Lambdasondensignal oberhalb der Fettschwelle befindet.
Sinkt es unter die Fettschwelle, so beginnt der Zeitzähler zu laufen. Er stoppt wieder, wenn das Lambdasondensignal unter die Magerschwelle abgefallen ist.
Bei der Umschaltung von mager nach fett bleibt der Zeitdauerzähler auf Null solange sich das Lambdasondensignal unterhalb der Magerschwelle befindet.
Steigt es über die Magerschwelle, so beginnt der Zeitzähler zu laufen. Er stoppt wieder, wenn das Lambdasondensignal über die Fettschwelle steigt. Als Fett- und Magerschwelle wird ein vorgebbarer Bruchteil des Maximalwerts des Lambdasondensignals definiert. Es wird beispielsweise als Fettschwelle 90% des Maximalwerts und als Magerschwelle 10% des Maximalwerts angenommen. Statt des letzten gemessenen einzelnen Maximalwerts beziehungsweise Minimalwerts kann dabei auch der über eine gleitende Mittelung aus den jeweiligen letzten tatsächlich gemessenen Werten ermittelte Wert verwendet werden.In step S1, the switching time TS is measured, which the lambda probe requires for a switch from rich to lean or from lean to rich.
The measurement is carried out, for example, with a clocked time counter. When switching from rich to lean, the duration counter remains at zero as long as the lambda sensor signal is above the fat threshold.
If it drops below the fat threshold, the time counter starts to run. It stops again when the lambda sensor signal has dropped below the lean threshold.
When switching from lean to rich, the time counter remains at zero as long as the lambda sensor signal is below the lean threshold.
If it rises above the lean threshold, the time counter starts to run. It stops again when the lambda probe signal rises above the fat threshold. A predeterminable fraction of the maximum value of the lambda probe signal is defined as the fat and lean threshold. For example, 90% of the maximum value is assumed as the fat threshold and 10% of the maximum value as the lean threshold. Instead of the last measured individual maximum value or minimum value, the value determined by means of a sliding averaging from the respective last actually measured values can also be used.

Wie im Verfahrensschritt S2 angedeutet ist, wird der Umschaltvorgang auf Umkehrpunkte kontrolliert. Ein Umkehrpunkt tritt auf, wenn im Schaltvorgang von fett nach mager das eigentlich stetig kleiner werdende Lambdasondensignal plötzlich wieder größer wird oder im Schaltvorgang von mager nach fett, das eigentlich stetig größer werdende Lambdasondensignal plötzlich wieder kleiner wird. Wird so ein Umkehrpunkt erkannt, wird diese Schaltzeit nicht zur Auswertung herangezogen.As indicated in step S2, the switching process is checked for reversal points. A reversal point occurs when the lambda sensor signal, which is actually steadily decreasing, suddenly becomes larger again in the switching process from rich to lean, or in the switching process from lean to rich, the lambda sensor signal, which is actually steadily increasing, suddenly becomes smaller again. If such a reversal point is recognized, this switching time is not used for evaluation.

Im Verfahrensschritt S3 wird kontrolliert, ob sich die Brennkraftmaschine in einem annähernd stationären Zustand befindet, d.h. ob sich Last und Drehzahl seit der letzten Schaltzeitmessung nicht erheblich geändert haben. Liegt kein solch annähernd stationärer Zustand vor, so wird die Schaltzeit ebenfalls nicht zur Auswertung herangezogen.In method step S3 it is checked whether the internal combustion engine is in an approximately stationary state, i.e. whether the load and speed have not changed significantly since the last switching time measurement. If there is no such approximately stationary state, the switching time is also not used for evaluation.

Liegt aber ein annähernd stationärer Zustand vor, so wird im Verfahrensschritt S4 geprüft, ob die Sonde von fett nach mager schaltet und dann weiter nach S5 verzweigt, oder ob die Sonde von mager nach fett schaltet und dann weiter nach S9 verzweigt.However, if there is an approximately stationary state, it is checked in method step S4 whether the probe switches from rich to lean and then branches to S5, or whether the probe switches from lean to rich and then branches to S9.

Im Verfahrensschritt S5 wird die aktuell ermittelte Schaltzeit TS zur Summe SFM der bisher schon ermittelten Schaltzeiten hinzugezählt.
Dann wird im Verfahrensschritt S6 aus einem Kennfeld in Abhängigkeit beispielsweise von der angesauten Luftmasse und der Drehzahl der Brennkraftmaschine der Schaltzeitengrenzwert FMG ausgelesen und zur Summe SFMG der bisher schon ausgelesenen Grenzwerte hinzugezählt.In method step S5, the currently determined switching time TS is added to the total SFM of the switching times already determined.
Then, in step S6, the switching time limit value FMG is read out from a map as a function of, for example, the air mass sucked in and the speed of the internal combustion engine and is added to the sum SFMG of the limit values already read out.

Im Verfahrensschritt S7 wird der Zähler ZF, der die Zahl der Umschaltungen von fett nach mager angibt, um eins erhöht.In method step S7, the counter ZF, which indicates the number of changes from rich to lean, is increased by one.

Im Verfahrensschritt S8 wird geprüft, ob der Wert des Zählers ZF kleiner ist, als ein vorgebbarer Auslösewert ZFA, der die Größe des Prüfzykluses festlegt. Ist dies der Fall, wird wieder zum Anfang des Verfahrens verzweigt. Ist der Wert aber gleich oder größer als der Auslösewert, wird im Verfahrensschritt S14 geprüft, ob die Summe der ermittelten Schaltzeiten SFM von fett nach mager kleiner als der Grenzwert SFMG ist. Ist dies der Fall, wird im Verfahrensschritt S16 angezeigt, daß die Lambdasonde in Ordnung ist. Ist der ermittelte Summenwert SFM aber gleich oder größer als der Grenzwert SFMG, so wird im Verfahrensschritt S15 angezeigt, daß die Lambdasonde defekt ist.
In beiden Fällen werden im Verfahrensschritt S17 die Zähler und Summanden zurückgesetzt und dann wird, sofern eine erneute Überprüfung der Lambdasonde stattfinden soll, zum Anfang des Verfahrens zurückgekehrt.In method step S8, it is checked whether the value of the counter ZF is smaller than a predefinable trigger value ZFA, which determines the size of the test cycle. If this is the case, the process branches back to the beginning of the procedure. However, if the value is equal to or greater than the trigger value, a check is carried out in method step S14 as to whether the sum of the switching times SFM determined from rich to lean is less than the limit value SFMG. If this is the case, it is indicated in method step S16 that the lambda probe is OK. If the total value SFM determined is equal to or greater than that Limit value SFMG, it is indicated in method step S15 that the lambda probe is defective.
In both cases, the counters and summands are reset in method step S17 and then, if the lambda probe is to be checked again, the method is returned to the beginning of the method.

Wird dagegen im Verfahrensschritt S4 erkannt, daß die Sonde von mager nach fett schaltet, dann wird weiter nach S9 verzweigt.If, on the other hand, it is recognized in method step S4 that the probe switches from lean to rich, the process continues to S9.

Im Verfahrensschritt S9 wird die aktuell ermittelte Schaltzeit TS zur Summe SMF der bisher schon ermittelten Schaltzeiten hinzugezählt.
Dann wird im Verfahrensschritt S10 aus einem Kennfeld wieder in Abhängigkeit von den aktuellen Betriebsbedingungen der Brennkraftmaschine (beispielsweise anhand der angesaugten Luftmasse und der aktuellen Drehzahl) der Schaltzeitengrenzwert MFG ausgelesen und zur Summe SMFG der bisher schon ausgelesenen Grenzwerte hinzugezählt.In method step S9, the currently determined switching time TS is added to the sum SMF of the switching times already determined.
Then, in step S10, the switching time limit value MFG is read out again from a map as a function of the current operating conditions of the internal combustion engine (for example on the basis of the intake air mass and the current speed) and added to the sum SMFG of the limit values already read out.

Im Verfahrensschritt S11 wird der Zähler ZM, der die Zahl der Umschaltungen von fett nach mager angibt, um eins erhöht.In step S11, the counter ZM, which indicates the number of changes from rich to lean, is increased by one.

Im Verfahrensschritt S12 wird geprüft, ob der Wert des Zählers ZM kleiner als ein Auslösewert ZMA ist. Ist dies der Fall, wird wieder zum Anfang des Verfahrens zurückgegangen. Ist der Wert aber gleich oder größer als der Auslösewert, wird im Verfahrensschritt S13 geprüft, ob die Summe der ermittelten Schaltzeiten SMF von mager nach fett kleiner als der Grenzwert SMFG ist. Ist dies der Fall wird, wie schon weiter oben beschrieben, im Verfahrensschritt S16 angezeigt, daß die Lambdasonde in Ordnung ist. Ist der Summenwert aber gleich oder größer als der Grenzwert wird, wie ebenfalls weiter oben schon beschrieben, im Verfahrensschritt S15 angezeigt, daß die Lambdasonde defekt ist.
Bei defekter Lambdasonde wird außerdem eine eventuell vorhandene Katalysatorwirkungsgradüberprüfung gesperrt.In step S12, it is checked whether the value of the counter ZM is less than a trigger value ZMA. If this is the case, the process is returned to the beginning of the procedure. If, however, the value is equal to or greater than the triggering value, it is checked in method step S13 whether the sum of the determined switching times SMF from lean to rich is less than the limit value SMFG. If this is the case, as already described above, step S16 indicates that the lambda probe is OK. If, however, the total value is equal to or greater than the limit value, it is indicated in method step S15 that the lambda probe is defective, as also described above is.
If the lambda probe is defective, any existing catalyst efficiency check is blocked.

Claims (8)

  1. Method for checking lambda probes, in which method, under working conditions of the lambda control circuit, a reference value (BW) is determined from the magnitude of the switching times (TS) in which the probe signal changes from a rich value to a lean value or from a lean value to a rich value and the probe is classified as working correctly if the reference value (BW) is lower than an assigned limit value, characterized in that a switching time (TS) is only taken into account if the profile of the probe signal does not have any reversal points during the switching process.
  2. Method according to Claim 1, characterized in that the checking of the probe is only carried out if the internal combustion engine is in a virtually steady-state operating range.
  3. Method according to Claim 1, characterized in that the switching times (TS) are subjected to averaging.
  4. Method according to Claim 1, characterized in that a prescribable number of switching times (TS) are added together in order to form the reference value (BW).
  5. Method according to Claim 1, characterized in that the limit value is obtained from a characteristic diagram as a function of the operating point, for example as a function of the intake air flow and the rotational speed of the internal combustion engine.
  6. Method according to Claim 1, characterized in that the switching times from rich to lean and from lean to rich are determined separately and separate reference values are formed therefrom and the said reference values are compared with separate limit values.
  7. Method according to Claim 1, characterized in that the value at which the probe signal has a prescribable first fraction of its maximum value is used as the rich value, and the value at which the probe signal has a prescribable second fraction of its maximum value is used as the lean value.
  8. Method according to Claim 1, characterized in that the value at which the probe signal has a prescribable first fraction of the value which is obtained by a sliding averaging of the maximum values measured last is used as the rich value and the value at which the probe signal has a second fraction of the value which is obtained by a sliding averaging of the maximum values measured last is used as the lean value.
EP93104163A 1993-03-15 1993-03-15 Method for monitoring a lambda sensor Expired - Lifetime EP0616119B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP93104163A EP0616119B1 (en) 1993-03-15 1993-03-15 Method for monitoring a lambda sensor
DE59306790T DE59306790D1 (en) 1993-03-15 1993-03-15 Procedure for checking lambda sensors
JP6068945A JPH06273281A (en) 1993-03-15 1994-03-15 Method for checking lambda sonde
US08/212,972 US5488858A (en) 1993-03-15 1994-03-15 Method for monitoring lambda sensors

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP93104163A EP0616119B1 (en) 1993-03-15 1993-03-15 Method for monitoring a lambda sensor

Publications (2)

Publication Number Publication Date
EP0616119A1 EP0616119A1 (en) 1994-09-21
EP0616119B1 true EP0616119B1 (en) 1997-06-18

Family

ID=8212694

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93104163A Expired - Lifetime EP0616119B1 (en) 1993-03-15 1993-03-15 Method for monitoring a lambda sensor

Country Status (4)

Country Link
US (1) US5488858A (en)
EP (1) EP0616119B1 (en)
JP (1) JPH06273281A (en)
DE (1) DE59306790D1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19859176C2 (en) * 1998-12-21 2003-07-10 Siemens Ag Procedure for checking the functionality of a lambda sensor
RU2643801C2 (en) * 2013-10-01 2018-02-06 Тойота Дзидося Кабусики Кайся System of diagnostics of air-to-fuel sensor fault

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08177575A (en) * 1994-12-28 1996-07-09 Nippondenso Co Ltd Self-diagnostic device for air-fuel ratio control device for internal combustion engine
DE19530316C1 (en) * 1995-08-17 1996-09-19 Siemens Ag Gas sensor diagnostic method for IC engine control
IT1285311B1 (en) * 1996-03-12 1998-06-03 Magneti Marelli Spa METHOD OF DIAGNOSING THE EFFICIENCY OF AN EXHAUST GAS STOICHIOMETRIC COMPOSITION SENSOR PLACED DOWNSTREAM OF A CONVERTER
US5945597A (en) * 1996-05-08 1999-08-31 Chrysler Corpoation Method for monitoring catalytic converter efficiency
US5801295A (en) * 1997-05-27 1998-09-01 Ford Global Technologies, Inc. On-board diagnostic test of oxygen sensor
DE19722334B4 (en) * 1997-05-28 2011-01-05 Robert Bosch Gmbh Exhaust gas diagnostic method and device
DE19733107C2 (en) 1997-07-31 2003-02-13 Siemens Ag Procedure for checking the functionality of a lambda sensor
DE19828929A1 (en) 1998-06-29 2000-01-05 Siemens Ag Method for checking the dynamic behavior of a sensor in the exhaust tract of an internal combustion engine
DE19844994C2 (en) 1998-09-30 2002-01-17 Siemens Ag Method for diagnosing a continuous lambda probe
DE10223554C1 (en) * 2002-05-27 2003-08-14 Siemens Ag Lambda probe diagnosis method detects output signal of lambda probe during periodic variation in engine fuel/air ratio for providing diagnosis value
DE10257284A1 (en) * 2002-12-07 2004-06-24 Robert Bosch Gmbh Circuit arrangement, for gas sensor e.g. in engine exhaust, comprises reference gas chamber containing reference electrode, flow source for feeding reference gas flow to electrode, and diagnostic arrangement containing constant-time device
DE10331331B4 (en) * 2003-07-10 2012-03-01 Volkswagen Ag Method for operating an internal combustion engine
JP4338586B2 (en) * 2004-05-26 2009-10-07 株式会社日立製作所 Engine exhaust system diagnostic device
JP4218601B2 (en) * 2004-06-29 2009-02-04 トヨタ自動車株式会社 Air-fuel ratio sensor deterioration judgment system for compression ignition internal combustion engine
US7460958B2 (en) * 2004-10-07 2008-12-02 E.I. Du Pont De Nemours And Company Computer-implemented system and method for analyzing mixtures of gases
ATE453043T1 (en) * 2006-04-18 2010-01-15 Iav Gmbh METHOD FOR ADJUSTING THE AIR/FUEL RATIO OF AN INTERNAL COMBUSTION ENGINE
US8065871B1 (en) 2007-01-02 2011-11-29 Cummins Ip, Inc Apparatus, system, and method for real-time diagnosis of a NOx-adsorption catalyst
JP2008261287A (en) * 2007-04-12 2008-10-30 Fuji Heavy Ind Ltd Filter clogging determination device of diesel engine
DE102007042086B4 (en) * 2007-09-05 2014-12-24 Continental Automotive Gmbh Test method for an exhaust gas probe of an internal combustion engine, in particular for a lambda probe
DE102007045080A1 (en) * 2007-09-21 2009-04-16 Continental Automotive Gmbh Method and apparatus for determining a dynamic property of an exhaust gas sensor
US7900616B2 (en) * 2007-12-12 2011-03-08 Denso Corporation Exhaust gas oxygen sensor monitoring
DE102008006631A1 (en) * 2008-01-29 2009-07-30 Volkswagen Ag Method for diagnosing dynamics of oxygen sensor arranged, downstream to catalytic converter, in exhaust gas stream of internal combustion engine of motor vehicle, involves determining two threshold values
US8756922B2 (en) 2011-06-10 2014-06-24 Cummins Ip, Inc. NOx adsorber catalyst condition evaluation apparatus and associated methods
DE102012211189A1 (en) * 2012-06-27 2014-01-02 Robert Bosch Gmbh Method for planning a vehicle diagnosis
DE102019204827A1 (en) * 2019-04-04 2020-10-08 Robert Bosch Gmbh Method for diagnosing exhaust gas sensors

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938075A (en) * 1974-09-30 1976-02-10 The Bendix Corporation Exhaust gas sensor failure detection system
JPS5319887A (en) * 1976-08-08 1978-02-23 Nippon Soken Deterioration detecting apparatus for oxygen concentration detector
US4191151A (en) * 1978-03-20 1980-03-04 General Motors Corporation Oxygen sensor signal processing circuit for a closed loop air/fuel mixture controller
JPS6024445A (en) * 1983-07-20 1985-02-07 Toyota Motor Corp Air-fuel ratio detector
JPS6218657U (en) * 1985-07-17 1987-02-04
US4750353A (en) * 1987-02-25 1988-06-14 Allied Corporation Method of voltage compensation for an air/fuel ratio sensor
DE3832123A1 (en) * 1987-10-09 1989-04-27 Fuji Heavy Ind Ltd DIAGNOSTIC SYSTEM FOR A MOTOR VEHICLE
DE3743315A1 (en) * 1987-12-21 1989-06-29 Bosch Gmbh Robert EVALUATION DEVICE FOR THE MEASURING SIGNAL OF A LAMB PROBE
AT393325B (en) * 1988-05-17 1991-09-25 Avl Verbrennungskraft Messtech METHOD FOR MEASURING THE LAMBDA AND / OR AIR / FUEL RATIO AND DEVICE FOR IMPLEMENTING THE METHOD
JPH0645646Y2 (en) * 1989-05-29 1994-11-24 株式会社ユニシアジェックス Misfire determination device for internal combustion engine
JPH0326844A (en) * 1989-06-21 1991-02-05 Japan Electron Control Syst Co Ltd Air-fuel ratio feedback correction device in fuel feed controller for internal combustion engine
JPH0670619B2 (en) * 1989-07-01 1994-09-07 日本碍子株式会社 Air-fuel ratio sensor evaluation method and device
US5269178A (en) * 1990-12-10 1993-12-14 Sensortech, L.P. Engine misfire, knock of roughness detection method and apparatus
US5287735A (en) * 1990-12-10 1994-02-22 Sensortech L.P. Engine misfire or roughness detection method and apparatus
JPH04109445U (en) * 1991-03-08 1992-09-22 本田技研工業株式会社 Failure diagnosis device for air-fuel ratio sensor of internal combustion engine
US5335539A (en) * 1991-08-30 1994-08-09 Ford Motor Company Onboard detection of oxygen sensor switch rate for determining air/fuel ratio control system failure

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19859176C2 (en) * 1998-12-21 2003-07-10 Siemens Ag Procedure for checking the functionality of a lambda sensor
RU2643801C2 (en) * 2013-10-01 2018-02-06 Тойота Дзидося Кабусики Кайся System of diagnostics of air-to-fuel sensor fault

Also Published As

Publication number Publication date
US5488858A (en) 1996-02-06
DE59306790D1 (en) 1997-07-24
EP0616119A1 (en) 1994-09-21
JPH06273281A (en) 1994-09-30

Similar Documents

Publication Publication Date Title
EP0616119B1 (en) Method for monitoring a lambda sensor
DE2733524C3 (en)
DE102008042549B4 (en) Method and device for diagnosing an exhaust gas probe
DE102008001569B4 (en) Method and device for adapting a dynamic model of an exhaust gas probe
EP2997242B1 (en) Method for determining a soot load in a particulate filter, a control unit, and a motor vehicle
DE102009000286B4 (en) Monitoring a particle limit value in the exhaust gas of an internal combustion engine
DE102007059772B4 (en) Method for determining the oxygen storage capacity of a catalytic converter for a motor vehicle and associated measuring device
EP0576705A1 (en) Method for detecting misfire
WO2004040104A1 (en) Method for testing at least three sensors, which detect a measurable variable for an internal combustion engine
DE19752965A1 (en) External ignition IC engine exhaust-gas cleaning system monitoring method
DE102008001213A1 (en) Method and device for diagnosing the dynamics of an exhaust gas sensor
EP1581734B1 (en) Method and device for diagnosing the dynamic characteristics of a lambda probe, used for the lambda regulation of individual cylinders
EP1222385A1 (en) Device and method for ignition in an internal combustion engine
DE19733107A1 (en) Method of checking lambda probes of IC engine
EP1770384A2 (en) Process and device for detecting a misfire
EP0652358A2 (en) Method for examination of the functioning capacity of lambda probes
DE19540673A1 (en) Method for checking the functionality of a catalytic converter with an oxygen sensor
DE2620985C2 (en) Test device for an air-fuel mixture control system
WO1994028292A1 (en) Catalyst effectiveness checking process
DE10341454A1 (en) Method for checking at least three sensors that detect a measurement variable in the area of an internal combustion engine
DE10003228A1 (en) Measurement of exhaust nitrogen oxide downstream of storage catalyst, includes stage in which minimum value is found, forming sensor zero calibration signal
DE102008023893A1 (en) Method for diagnosing the functionality of a jumping probe
DE19901066C1 (en) Method for detecting passage-reducing changes in an exhaust gas catalytic converter body
DE10056320A1 (en) Process for diagnosing the end stage of a heating device of a gas sensor comprises using a prescribed diagnosis value as a sensor condition signal and/or a prescribed diagnosis value of a heating voltage parameter signal
DE102012207639A1 (en) Method for dynamic diagnosis of e.g. wide band lambda probe in exhaust gas passage of petrol engine in car, involves changing dynamic parameters of exhaust gas probe in relation to nominal values based on result of mathematical formula

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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE

RBV Designated contracting states (corrected)

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19941205

17Q First examination report despatched

Effective date: 19960220

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19970618

REF Corresponds to:

Ref document number: 59306790

Country of ref document: DE

Date of ref document: 19970724

ET Fr: translation filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19970902

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20090325

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20090312

Year of fee payment: 17

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20100315

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20101130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100315

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20120331

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 59306790

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20130316