EP2531706A1 - Diagnostic method for a soot sensor - Google Patents

Diagnostic method for a soot sensor

Info

Publication number
EP2531706A1
EP2531706A1 EP11702962A EP11702962A EP2531706A1 EP 2531706 A1 EP2531706 A1 EP 2531706A1 EP 11702962 A EP11702962 A EP 11702962A EP 11702962 A EP11702962 A EP 11702962A EP 2531706 A1 EP2531706 A1 EP 2531706A1
Authority
EP
European Patent Office
Prior art keywords
soot sensor
temperature
measured value
exhaust system
soot
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Withdrawn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
EP11702962A
Other languages
German (de)
French (fr)
Inventor
Johannes Ante
Rudolf Bierl
Markus Herrmann
Andreas Ott
Willibald Reitmeier
Denny SCHÄDLICH
Manfred Weigl
Andreas Wildgen
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.)
Continental Automotive GmbH
Original Assignee
Continental Automotive GmbH
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 Continental Automotive GmbH filed Critical Continental Automotive GmbH
Publication of EP2531706A1 publication Critical patent/EP2531706A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M15/00—Testing of engines
    • G01M15/04—Testing internal-combustion engines
    • 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
    • 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
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1466—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being a soot concentration or content
    • 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
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F15/00—Digital computers in general; Data processing equipment in general
    • 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
    • F01N2560/05—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a particulate sensor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/06—Investigating concentration of particle suspensions
    • 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 present invention relates to a diagnostic method of a soot sensor disposed in an exhaust system of an internal combustion engine.
  • Modern motor vehicles with internal combustion engine are equipped with a particulate filter to avoid harmful to health and the environment particle emissions.
  • the exhaust gas flows through the exhaust gas during operation of the internal combustion engine and filters out a predominant number of particles from the exhaust gas.
  • an amount of particles collected in the particle filter is so large that clogging of the particle filter begins.
  • This clogging is detected by a monitoring device consisting of various sensors, a control device and corresponding software.
  • the various sensors are in particular differential pressure sensors and temperature sensors.
  • the control device selects a point in time and changes the injection conditions such that an exhaust gas temperature is increased. In this way, particles accumulated in the particle filter are burned (so-called burn-off of the particle filter). Upon completion of this burn-off, the particulate filter is regenerated.
  • soot sensor Correct operation of the particulate filter is monitored, for example, with a particulate or soot sensor.
  • the soot sensor should unambiguously detect a malfunction of the particulate filter and then be able to display a detected malfunction to a user of the motor vehicle.
  • soot sensors which provide an electrical conductivity of the particles above the resistance. measure stand.
  • the measurement of particulate dielectric losses may be performed in a suitable capacitor.
  • a method and a device for monitoring the particle concentration in a gas stream is described, for example, in DE 10 2004 007 634 A1.
  • This document proposes a particle collecting sensor in the exhaust stream.
  • the sensor is integrated as a capacitive element in an electromagnetic resonance circuit.
  • the soot sensor comprises a chip connected to electrical terminals via connection pads, wherein at least one electrical property of the chip from the group resistance, capacitance and impedance can be changed by soot action.
  • the above-mentioned sensors collect soot particles on a small ceramic plate and measure the change in electrical properties, such as falling resistance or increasing capacitive losses.
  • a clear assignment of the electrical measurement data of the sensor to the amount of soot is difficult to achieve due to other substances occurring in the exhaust system.
  • a disadvantage of the above sensors is that a sensor coated with soot automatically cleans itself during operation of the internal combustion engine during full load operation over a certain period of time or during a particle filter regeneration because of increased exhaust gas temperature. This means that the soot on the sensor surface burns off automatically.
  • a further disadvantage is that with recurring low temperatures, in particular with many cold starts and comparatively only short full-load phases, the sensor can be so heavily coated with soot and other substances that no meaningful measured values can be achieved with the soot sensor. In this case, the Sensor heated by a built-in heater so far that burns the deposited soot.
  • a diagnostic method of a soot sensor disposed in an exhaust system of an internal combustion engine comprises the steps of: detecting a first temperature in the exhaust system, determining whether the detected first temperature is below 100 ° C, if so: detecting a first measurement with the soot sensor, which is arranged in the exhaust system, comparing the first measured value with a predeterminable limit value and, if the first measured value exceeds the predeterminable limit value, determining that the sensor is in order.
  • a soot sensor is disposed in an exhaust system of an internal combustion engine.
  • the internal combustion engine is for example a diesel engine.
  • the exhaust system has in particular a particle filter.
  • the soot sensor is arranged downstream of the particle filter in the flow direction of the exhaust gas.
  • the exhaust system has at least one temperature sensor.
  • the at least one temperature sensor is preferably between a catalyst in the exhaust system and the particulate filter or arranged behind the particle filter in the flow direction. Likewise, temperature sensors may be present at both locations.
  • the exhaust system may include a differential pressure sensor which detects a pressure difference between a pressure measuring point in the flow direction upstream of the particle filter and a pressure measuring point in the flow direction behind the particle filter.
  • the sensors used are connected to a control unit.
  • the control unit evaluates the signals transmitted by the sensors and transmits corresponding control signals to the internal combustion engine.
  • a first temperature in the exhaust system is detected. It is particularly advantageous if the temperature is detected adjacent to the soot sensor in the exhaust system. If, for example, the soot sensor is arranged behind a particle filter, a temperature sensor is likewise arranged behind the particle filter.
  • a second step it is determined whether the detected first temperature is below 100 ° C. If this is the case, then a first measured value is detected with the soot sensor. This detected first measured value is compared with a predefinable limit value, for example in a motor controller. If the first measured value exceeds the predefinable limit value, then it is determined that the sensor is in order.
  • cross-sensitivities of the soot sensor to other substances for soot sensor self-diagnosis are used.
  • the substances used for self-diagnosis must in particular be able to pass through the intact particle filter in normal operation.
  • a water content contained in the exhaust stream is suitable.
  • the diagnostic method has the further steps of detecting a second temperature in the exhaust system, determining whether the detected second temperature is above 100 ° C, if so: detecting a second measured value with the soot sensor, comparing the second measured value with the predetermined limit value and, if the second measured value falls below the predeterminable limit value, determining that the sensor is in order.
  • the diagnostic method according to the invention can be improved.
  • the soot sensor outputs a signal which is, for example, in the upper third of a measured value range of the soot sensor.
  • the temperature rises in the exhaust system and exceeds after a certain time a temperature of 100 ° C.
  • a signal caused by a water content in the exhaust gas signal of the soot sensor must not occur after exceeding the 100 ° C mark.
  • detecting a third temperature determining whether the detected third temperature is above 100 ° C, if so: determining an operating condition of the internal combustion engine, detecting a third measured value with the soot sensor, comparing the third measured value with the predeterminable limit value and , if the specifiable limit value is fallen short of, determining that a particulate filter in the exhaust system is in order, or, if the specified value is exceeded, limit value, determination that a particulate filter in the exhaust system is defective.
  • the self-diagnosis of the soot sensor can be used in addition lent to check the operability of a arranged in the exhaust system particulate filter. If the operating state of the internal combustion engine is, for example, full load, the soot sensor may output almost no signal when the particle filter is intact and at a temperature above 100 ° C. However, if the signal of the soot sensor increases or exceeds a predefinable limit value, then soot exits the particle filter. The particle filter is defective.
  • a self-diagnosis of the soot sensor can be checked during operation of the internal combustion engine, in particular during prolonged operation.
  • the high measured value of the soot sensor directly after the particle filter burns out is based, in particular, on the fact that particularly many small particles can pass the particle filter directly after burnout. This has resulted in a signal increase in the soot sensor.
  • a fifth measured value can be detected with the soot sensor, for example, after a predeterminable time after the particle filter has burnt out.
  • the fifth measured value must then again be below the specifiable limit value so that the sensor is recognized as being OK.
  • the diagnostic method of the soot sensor is carried out in a control unit of a motor vehicle with an internal combustion engine, in particular in a motor vehicle with a diesel engine.
  • the sensor is not recognized as being OK, for example, either a corresponding flag can be set in the control unit or a signal can be output to a user of the motor vehicle.
  • the signal is, in particular, an optical and / or acoustic signal.
  • FIG. 1 is a schematic representation of an exhaust system of an internal combustion engine
  • FIG. 2 shows a schematic process sequence of a diagnostic method according to the invention of a soot sensor.
  • FIG. 1 shows an exhaust system 1 of an internal combustion engine 3.
  • the internal combustion engine 3 is, for example, a diesel engine.
  • the exhaust system 1 is in particular part of a motor vehicle (not shown).
  • the flow direction of the exhaust gas from the internal combustion engine 3 is shown by the arrow 22.
  • On the internal combustion engine 3, an exhaust pipe 24 is arranged.
  • In the exhaust line 24 are in the flow direction of the exhaust gas (arrow 22) after the internal combustion engine 3, a catalyst 5 and a particulate filter 7.
  • a control unit 10 is further provided, which is connected by means of signal lines 12 to the internal combustion engine 3.
  • temperature sensors 14, a differential pressure sensor 16 and a soot sensor 18 are arranged in the exhaust gas line 24 in the exhaust system 1.
  • the sensors are each connected to the control unit 10 by means of signal lines 20. the.
  • the control unit evaluates the signals transmitted by the sensors 14, 16 and 18 and outputs corresponding control signals via the control signal lines 12 to the internal combustion engine 3.
  • the temperature sensors 14 are arranged in the exhaust pipe behind the catalyst 5, in front of the particle filter 7 and behind the particle filter 7.
  • the differential pressure sensor 16 has a measuring point in front of the particle filter 7 and a measuring point behind the particle filter 7.
  • the soot sensor 18 is in
  • a temperature sensor 14 detects a first temperature in the exhaust system 1 in a step A.
  • this is the temperature sensor 14 which is arranged adjacent to the soot sensor 18 in the exhaust line 24.
  • the control unit 10 determines in step B whether the detected by the temperature sensor 14 first temperature is below 100 ° C. In this way, for example, a cold start of the internal combustion engine 3 can be detected. If the detected temperature is below 100 ° C, the soot sensor 18 detects in one
  • Step C a first measured value.
  • the control unit 10 compares the first measured value in a step D with a predefinable limit value.
  • the predefinable limit value is, for example, in the middle of the measuring range of the soot sensor or at two thirds or three quarters of the measuring range of the soot sensor. If the first measured value exceeds the predefinable limit value, then the control unit 10 determines in step E that the soot sensor is in order.
  • a second temperature in the exhaust system is detected. This is preferably done by the same temperature tursensor 14, with which also the first temperature was detected.
  • the control unit 10 determines whether the detected second temperature is above 100 ° C. If this is the case, then in step H a second measured value is detected with the soot sensor 18.
  • the control unit 10 compares the detected second measured value with the predefinable limit value in step I and determines in step J that the soot sensor is in order if the second measured value falls below the predefinable limit value.
  • steps F and G are repeated until the temperature in the exhaust system exceeds 100 ° C.
  • step K a third temperature is detected.
  • the control unit 10 determines in step L whether the detected third temperature is above 100 ° C and then sets in
  • Step N determines an operating condition of the internal combustion engine when the temperature is over 100 ° C.
  • the operating state of the internal combustion engine 3 determined in step N is full load or is in the upper third of a rotational speed range of the internal combustion engine, then in step N, a third measured value is acquired by the soot sensor 18.
  • the third measured value becomes the predefinable limit value in step 0 compared.
  • the control unit determines that a particulate filter in the exhaust system is in order (Ol) or faulty (02).
  • step P a free-burning process of the particulate filter 7 in the exhaust system 1 is determined in step P.
  • step Q a fourth measured value is detected with the soot sensor 18 and compared in step R with the predeterminable limit value. If the fourth measured value exceeds the predefinable limit value, then it is determined in step S that the soot sensor 18 is in order.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Computer Hardware Design (AREA)
  • Processes For Solid Components From Exhaust (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The invention relates to a diagnostic method for a soot sensor that lies in an exhaust gas system of an internal combustion engine. First, a first temperature in the exhaust gas system is detected, and it is determined whether the detected first temperature is below a 100 °C. If this is the case, a first measured value is then detected with the soot sensor and compared with a specifiable threshold value. If the first measured value exceeds the specifiable threshold value, the soot sensor is determined to be operating properly.

Description

Beschreibung description
Diagnoseverfahren eines Rußsensors Die vorliegende Erfindung betrifft ein Diagnoseverfahren eines Rußsensors, der in einem Abgassystem einer Brennkraftmaschine angeordnet ist. The present invention relates to a diagnostic method of a soot sensor disposed in an exhaust system of an internal combustion engine.
Moderne Kraftfahrzeuge mit Brennkraftmaschine, insbesondere Kraftfahrzeuge mit einem Dieselmotor, werden mit einem Partikelfilter ausgerüstet, um gesundheits- und umweltschädlichen Partikelausstoß zu vermeiden. Der Partikelfilter wird im Betrieb der Brennkraftmaschine vom Abgas durchströmt und filtert eine überwiegende Zahl von Partikeln aus dem Abgas . In Abhängigkeit von einer Betriebszeit der Brennkraftmaschine bzw. einer Fahrstrecke des Kraftfahrzeugs ist eine in dem Partikelfilter gesammelte Menge an Partikeln so groß, dass ein Verstopfen des Partikelfilters beginnt. Dieses Verstopfen wird von einer Überwachungsvorrichtung bestehend aus ver- schiedenen Sensoren, einer Steuereinrichtung sowie entsprechender Software erkannt. Bei den verschiedenen Sensoren handelt es sich insbesondere um Differenzdrucksensoren und Temperatursensoren. Zur Reinigung des Partikelfilters wählt die Steuereinrichtung einen Zeitpunkt aus und verändert die Ein- spritzbedingungen derart, dass eine Abgastemperatur erhöht wird. Auf diese Weise werden in dem Partikelfilter angelagerte Partikel verbrannt (sogenanntes Freibrennen des Partikelfilters). Nach Abschluss dieses Freibrennens ist der Partikelfilter regeneriert. Modern motor vehicles with internal combustion engine, especially motor vehicles with a diesel engine, are equipped with a particulate filter to avoid harmful to health and the environment particle emissions. The exhaust gas flows through the exhaust gas during operation of the internal combustion engine and filters out a predominant number of particles from the exhaust gas. Depending on an operating time of the internal combustion engine or a driving distance of the motor vehicle, an amount of particles collected in the particle filter is so large that clogging of the particle filter begins. This clogging is detected by a monitoring device consisting of various sensors, a control device and corresponding software. The various sensors are in particular differential pressure sensors and temperature sensors. To clean the particulate filter, the control device selects a point in time and changes the injection conditions such that an exhaust gas temperature is increased. In this way, particles accumulated in the particle filter are burned (so-called burn-off of the particle filter). Upon completion of this burn-off, the particulate filter is regenerated.
Ein korrekter Betrieb des Partikelfilters wird beispielsweise mit einem Partikel- oder Rußsensor überwacht. Der Rußsensor soll eine Fehlfunktion des Partikelfilters zweifelsfrei feststellen und eine festgestellte Fehlfunktion anschließend ei- nem Benutzer des Kraftfahrzeugs anzeigen können. Neben elektrostatisch messenden Rußsensoren gibt es Rußsensoren, die eine elektrische Leitfähigkeit der Partikel über den Wider- stand messen. Alternativ kann die Messung von partikelbedmg- ten dielektrischen Verlusten in einem geeigneten Kondensator durchgeführt werden. Correct operation of the particulate filter is monitored, for example, with a particulate or soot sensor. The soot sensor should unambiguously detect a malfunction of the particulate filter and then be able to display a detected malfunction to a user of the motor vehicle. In addition to electrostatically measuring soot sensors, there are soot sensors, which provide an electrical conductivity of the particles above the resistance. measure stand. Alternatively, the measurement of particulate dielectric losses may be performed in a suitable capacitor.
Ein Verfahren und eine Vorrichtung zur Überwachung der Partikelkonzentration in einem Gasstrom ist beispielsweise in DE 10 2004 007 634 AI beschrieben. Dieses Dokument schlägt einen Partikel sammelnden Sensor im Abgasstrom vor. Der Sensor ist als kapazitives Element in einen elektromagnetischen Resonanzkreis integriert. A method and a device for monitoring the particle concentration in a gas stream is described, for example, in DE 10 2004 007 634 A1. This document proposes a particle collecting sensor in the exhaust stream. The sensor is integrated as a capacitive element in an electromagnetic resonance circuit.
Eine alternative Ausführungsform eines Rußsensors ist in DE 10 2005 029 219 AI beschrieben. Der Rußsensor umfasst einen über Anschlusspads mit elektrischen Anschlüssen verbundenen Chip, wobei wenigstens eine elektrische Eigenschaft des Chips aus der Gruppe Widerstand, Kapazität und Impedanz durch Rußeinwirkung änderbar ist. An alternative embodiment of a soot sensor is described in DE 10 2005 029 219 AI. The soot sensor comprises a chip connected to electrical terminals via connection pads, wherein at least one electrical property of the chip from the group resistance, capacitance and impedance can be changed by soot action.
Die oben genannten Sensoren sammeln Rußpartikel auf einem kleinen keramischen Plättchen und messen die Veränderung der elektrischen Eigenschaften, beispielsweise fallender Widerstand oder steigende kapazitive Verluste. Eine eindeutige Zuordnung der elektrischen Messdaten des Sensors zur Rußmenge ist auf Grund anderer im Abgasstrang auftretender Stoffe schwer realisierbar. The above-mentioned sensors collect soot particles on a small ceramic plate and measure the change in electrical properties, such as falling resistance or increasing capacitive losses. A clear assignment of the electrical measurement data of the sensor to the amount of soot is difficult to achieve due to other substances occurring in the exhaust system.
Ein Nachteil der obigen Sensoren ist, dass ein mit Ruß belegter Sensor bei einem Betrieb der Brennkraftmaschine im Volllastbetrieb über eine bestimmte Zeitdauer oder während einer Partikelfilterregeneration sich wegen erhöhter Abgastemperatur von selbst reinigt. Dies bedeutet, dass der Ruß auf der Sensoroberfläche selbsttätig abbrennt. Ein weiterer Nachteil ist, dass bei wiederkehrenden niedrigen Temperaturen, insbesondere bei vielen Kaltstarts und vergleichsweise nur kurzen Volllastphasen der Sensor so stark mit Ruß und anderen Stoffen belegt werden kann, dass keine sinnvollen Messwerte mit dem Rußsenor mehr erzielbar sind. In diesem Fall wird der Sensor durch eine eingebaute Heizung soweit erwärmt, dass der darauf abgelagerte Ruß verbrennt . A disadvantage of the above sensors is that a sensor coated with soot automatically cleans itself during operation of the internal combustion engine during full load operation over a certain period of time or during a particle filter regeneration because of increased exhaust gas temperature. This means that the soot on the sensor surface burns off automatically. A further disadvantage is that with recurring low temperatures, in particular with many cold starts and comparatively only short full-load phases, the sensor can be so heavily coated with soot and other substances that no meaningful measured values can be achieved with the soot sensor. In this case, the Sensor heated by a built-in heater so far that burns the deposited soot.
Eine Kontrolle der Funktionsfähigkeit des Rußsensors ist bis- her nur schwer realisierbar, da bei intaktem Partikelfilter kaum oder nur wenige Rußpartikel an den Sensor gelangen. Dies ist dadurch begründet, dass der Rußsensor für eine on-board- Diagnose (OBD) des Partikelfilters hinter dem Partikelfilter angeordnet ist. Control of the functionality of the soot sensor has hitherto been difficult to achieve, since with intact particulate filter hardly or only a few soot particles reach the sensor. This is due to the fact that the soot sensor for on-board diagnosis (OBD) of the particulate filter is arranged behind the particulate filter.
Die Aufgabe der vorliegenden Erfindung ist daher, die Bereitstellung eines Diagnoseverfahrens eines Rußsensors, der in einem Abgassystem einer Brennkraftmaschine angeordnet ist. Die obige Aufgabe wird gelöst durch ein Diagnoseverfahren eines Rußsensors gemäß Anspruch 1. Weitere vorteilhafte Ausführungsformen ergeben sich aus der nachfolgenden Beschreibung, den Zeichnungen sowie den Unteransprüchen. Ein Diagnoseverfahren eines Rußsensors, der in einem Abgassystem einer Brennkraftmaschine angeordnet ist, umfasst die folgenden Schritte: Erfassen einer ersten Temperatur im Abgassystem, Feststellen, ob die erfasste erste Temperatur unter 100 °C liegt, wenn ja: Erfassen eines ersten Messwerts mit dem Rußsensor, der in dem Abgassystem angeordnet ist, vergleichen des ersten Messwerts mit einem vorgebbaren Grenzwert und, wenn der erste Messwert den vorgebbaren Grenzwert überschreitet, Feststellen, dass der Sensor in Ordnung ist. Ein Rußsensor ist in einem Abgassystem einer Brennkraftmaschine angeordnet. Die Brennkraftmaschine ist beispielsweise ein Dieselmotor. Das Abgassystem weist insbesondere einen Partikelfilter auf. Der Rußsensor ist in Strömungsrichtung des Abgases hinter dem Partikelfilter angeordnet. Weiterhin weist das Abgassystem mindestens einen Temperatursensor auf. Der mindestens eine Temperatursensor ist vorzugsweise zwischen einem Katalysator im Abgassystem und dem Partikelfilter oder in Strömungsrichtung hinter dem Partikelfilter angeordnet. Ebenso können an beiden Stellen Temperatursensoren vorhanden sein. Weiterhin kann das Abgassystem einen Differenzdrucksensor aufweisen, der eine Druckdifferenz zwischen einer Druckmessstelle in Strömungsrichtung vor dem Partikelfilter und einer Druckmessstelle in Strömungsrichtung hinter dem Partikelfilter erfasst. Die verwendeten Sensoren sind mit einer Steuereinheit verbunden. Die Steuereinheit wertet die von den Sensoren übermittelten Signale aus und übermittelt ent- sprechende Steuersignale an die Brennkraftmaschine. The object of the present invention is therefore to provide a diagnostic method of a soot sensor disposed in an exhaust system of an internal combustion engine. The above object is achieved by a diagnostic method of a soot sensor according to claim 1. Further advantageous embodiments will become apparent from the following description, the drawings and the dependent claims. A diagnostic method of a soot sensor disposed in an exhaust system of an internal combustion engine comprises the steps of: detecting a first temperature in the exhaust system, determining whether the detected first temperature is below 100 ° C, if so: detecting a first measurement with the soot sensor, which is arranged in the exhaust system, comparing the first measured value with a predeterminable limit value and, if the first measured value exceeds the predeterminable limit value, determining that the sensor is in order. A soot sensor is disposed in an exhaust system of an internal combustion engine. The internal combustion engine is for example a diesel engine. The exhaust system has in particular a particle filter. The soot sensor is arranged downstream of the particle filter in the flow direction of the exhaust gas. Furthermore, the exhaust system has at least one temperature sensor. The at least one temperature sensor is preferably between a catalyst in the exhaust system and the particulate filter or arranged behind the particle filter in the flow direction. Likewise, temperature sensors may be present at both locations. Furthermore, the exhaust system may include a differential pressure sensor which detects a pressure difference between a pressure measuring point in the flow direction upstream of the particle filter and a pressure measuring point in the flow direction behind the particle filter. The sensors used are connected to a control unit. The control unit evaluates the signals transmitted by the sensors and transmits corresponding control signals to the internal combustion engine.
In einem ersten Schritt des erfindungsgemäßen Diagnoseverfahrens des Rußsensors wird eine erste Temperatur im Abgassystem erfasst. Besonders vorteilhaft ist, wenn die Temperatur be- nachbart zum Rußsensor im Abgassystem erfasst wird. Ist beispielsweise der Rußsensor hinter einem Partikelfilter angeordnet, so ist ein Temperatursensor ebenfalls hinter dem Partikelfilter angeordnet. In einem zweiten Schritt wird festgestellt, ob die erfasste erste Temperatur unter 100 °C liegt. Ist dies der Fall, dann wird mit dem Rußsensor ein erster Messwert erfasst. Dieser erfasste erste Messwert wird mit einem vorgebbaren Grenzwert, beispielsweise in einer Motorsteuerung, verglichen. Über- schreitet der erste Messwert den vorgebbaren Grenzwert, dann wird festgestellt, dass der Sensor in Ordnung ist. In a first step of the diagnostic method according to the invention of the soot sensor, a first temperature in the exhaust system is detected. It is particularly advantageous if the temperature is detected adjacent to the soot sensor in the exhaust system. If, for example, the soot sensor is arranged behind a particle filter, a temperature sensor is likewise arranged behind the particle filter. In a second step, it is determined whether the detected first temperature is below 100 ° C. If this is the case, then a first measured value is detected with the soot sensor. This detected first measured value is compared with a predefinable limit value, for example in a motor controller. If the first measured value exceeds the predefinable limit value, then it is determined that the sensor is in order.
Mit dem erfindungsgemäßen Verfahren werden Querempfindlichkeiten des Rußsensors auf andere Stoffe zur Rußsensor-Eigen- diagnose genutzt. Die zur Eigendiagnose verwendeten Stoffe müssen insbesondere den intakten Partikelfilter in einem normalen Betrieb passieren können. Hierzu eignet sich ein im Abgasstrom enthaltener Wasseranteil. Durch das Erfassen der ersten Temperatur und Feststellen, ob die erste Temperatur un- ter 100 °C liegt, wird insbesondere auf einen Kaltstart derWith the method according to the invention, cross-sensitivities of the soot sensor to other substances for soot sensor self-diagnosis are used. The substances used for self-diagnosis must in particular be able to pass through the intact particle filter in normal operation. For this purpose, a water content contained in the exhaust stream is suitable. By detecting the first temperature and determining whether the first temperature is below 100 ° C, in particular a cold start of the
Brennkraftmaschine abgezielt. Auf diese Weise kann eine erste Überprüfung einer Funktionsfähigkeit des Rußsensors beim Starten der Brennkraftmaschine eines Kraftfahrzeugs erfolgen. Targeted internal combustion engine. In this way, a first Checking a functioning of the soot sensor when starting the internal combustion engine of a motor vehicle.
In einer vorteilhaften Ausführungsform weist das Diagnosever- fahren die weiteren Schritte auf: Erfassen einer zweiten Temperatur im Abgassystem, Feststellen, ob die erfasste zweite Temperatur über 100 °C liegt, wenn ja: Erfassen eines zweiten Messwerts mit dem Rußsensor, Vergleichen des zweiten Messwerts mit dem vorgebbaren Grenzwert und, wenn der zweite Messwert den vorgebbaren Grenzwert unterschreitet, Feststellen, dass der Sensor in Ordnung ist. In an advantageous embodiment, the diagnostic method has the further steps of detecting a second temperature in the exhaust system, determining whether the detected second temperature is above 100 ° C, if so: detecting a second measured value with the soot sensor, comparing the second measured value with the predetermined limit value and, if the second measured value falls below the predeterminable limit value, determining that the sensor is in order.
Mit Hilfe dieser weiteren Verfahrens schritte kann das erfindungsgemäße Diagnoseverfahren verbessert werden. Hierbei wird insbesondere darauf abgestellt, dass ein durch einen Wasseranteil im Abgas hervorgerufenes Messsignal bei einer Temperatur im Abgassystem über 100 °C nicht mehr auftreten darf. With the aid of these further method steps, the diagnostic method according to the invention can be improved. In this case, it is particularly important that a measurement signal caused by a water content in the exhaust gas must no longer occur at a temperature in the exhaust system above 100 ° C.
Insgesamt bedeutet dies, dass nach einem Kaltstart der Brenn- kraftmaschine der Rußsensor ein Signal ausgibt, das beispielsweise im oberen Drittel eines Messwertbereichs des Rußsensors liegt. In Abhängigkeit von einer Betriebsdauer der Brennkraftmaschine steigt die Temperatur im Abgassystem an und überschreitet nach einer bestimmten Zeit eine Temperatur von 100 °C. Ein durch einen Wasseranteil im Abgas hervorgerufenes Signal des Rußsensors darf nach Überschreiten der 100 °C Marke nicht mehr auftreten. Overall, this means that after a cold start of the internal combustion engine, the soot sensor outputs a signal which is, for example, in the upper third of a measured value range of the soot sensor. Depending on an operating time of the internal combustion engine, the temperature rises in the exhaust system and exceeds after a certain time a temperature of 100 ° C. A signal caused by a water content in the exhaust gas signal of the soot sensor must not occur after exceeding the 100 ° C mark.
Weiterhin bevorzugt sind die Schritte: Erfassen einer dritten Temperatur, Feststellen, ob die erfasste dritte Temperatur über 100 °C liegt, wenn ja: Feststellen eines Betriebszustands der Brennkraftmaschine, Erfassen eines dritten Messwerts mit dem Rußsensor, Vergleich des dritten Messwerts mit dem vorgebbaren Grenzwert und, bei Unterschreiten des vorgeb- baren Grenzwerts, Feststellen, dass ein Partikelfilter im Abgassystem in Ordnung ist, oder, bei Überschreiten des vorgeb- baren Grenzwerts, Feststellen, dass ein Partikelfilter im Abgassystem defekt ist. Further preferred are the steps: detecting a third temperature, determining whether the detected third temperature is above 100 ° C, if so: determining an operating condition of the internal combustion engine, detecting a third measured value with the soot sensor, comparing the third measured value with the predeterminable limit value and , if the specifiable limit value is fallen short of, determining that a particulate filter in the exhaust system is in order, or, if the specified value is exceeded, limit value, determination that a particulate filter in the exhaust system is defective.
Auf diese Weise kann die Eigendiagnose des Rußsensors zusätz- lieh zur Überprüfung der Funktionsfähigkeit eines im Abgassystem angeordneten Partikelfilters verwendet werden. Ist der Betriebszustand der Brennkraftmaschine beispielsweise Volllast, darf der Rußsensor bei intaktem Partikelfilter und einer Temperatur über 100 °C annähernd kein Signal abgeben. Nimmt das Signal des Rußsensors jedoch zu oder überschreitet einen vorgebbaren Grenzwert, dann tritt Ruß aus dem Partikelfilter aus. Der Partikelfilter ist defekt. In this way, the self-diagnosis of the soot sensor can be used in addition lent to check the operability of a arranged in the exhaust system particulate filter. If the operating state of the internal combustion engine is, for example, full load, the soot sensor may output almost no signal when the particle filter is intact and at a temperature above 100 ° C. However, if the signal of the soot sensor increases or exceeds a predefinable limit value, then soot exits the particle filter. The particle filter is defective.
Weiterhin bevorzugt sind die Schritte: Feststellen eines Freibrennvorgangs des Partikelfilters im Abgassystem, anschließend Erfassen eines vierten Messwerts mit dem Rußsensor, Vergleichen des vierten Messwerts mit dem vorgebbaren Grenzwert und, wenn der vierte Messwert den vorgebbaren Grenzwert überschreitet, Feststellen, dass der Rußsensor in Ordnung ist. Further preferred are the steps: detecting a free-burning operation of the particulate filter in the exhaust system, then detecting a fourth measured value with the soot sensor, comparing the fourth measured value with the predeterminable limit value and, if the fourth measured value exceeds the predeterminable limit value, determining that the soot sensor is in order ,
Mit diesen Verfahrensschritten kann eine Eigendiagnose des Rußsensors während eines Betriebs der Brennkraftmaschine, insbesondere während eines länger anhaltenden Betriebs über- prüft werden. Der hohe Messwert des Rußsensors direkt nach einem Freibrennen des Partikelfilters beruht insbesondere darauf, dass direkt nach dem Freibrennen besonders viele kleine Partikel den Partikelfilter passieren können. Dies hat einen Signalanstieg im Rußsensor zur Folge hat. With these method steps, a self-diagnosis of the soot sensor can be checked during operation of the internal combustion engine, in particular during prolonged operation. The high measured value of the soot sensor directly after the particle filter burns out is based, in particular, on the fact that particularly many small particles can pass the particle filter directly after burnout. This has resulted in a signal increase in the soot sensor.
Zur weiteren Verbesserung des Verfahrens kann beispielsweise nach einer vorgebbaren Zeit nach dem Freibrennen des Partikelfilters ein fünfter Messwert mit dem Rußsensor erfasst werden. Der fünfte Messwert muss dann erneut unter dem vor- gebbaren Grenzwert liegen, damit der Sensor als in Ordnung erkannt wird. Besonders vorteilhaft ist, wenn das Diagnoseverfahren des Rußsensors in einer Steuereinheit eines Kraftfahrzeugs mit Brennkraftmaschine durchgeführt wird, insbesondere in einem Kraftfahrzeug mit Dieselmotor. In diesem Fall kann dann, wenn der Sensor nicht als in Ordnung erkannt wird, beispielsweise entweder ein entsprechender Merker in der Steuereinheit gesetzt werden oder ein Signal an einen Nutzer des Kraftfahrzeugs ausgegeben werden. Bei dem Signal handelt es sich insbesondere um ein optisches und/oder akustisches Signal. To further improve the method, a fifth measured value can be detected with the soot sensor, for example, after a predeterminable time after the particle filter has burnt out. The fifth measured value must then again be below the specifiable limit value so that the sensor is recognized as being OK. It is particularly advantageous if the diagnostic method of the soot sensor is carried out in a control unit of a motor vehicle with an internal combustion engine, in particular in a motor vehicle with a diesel engine. In this case, if the sensor is not recognized as being OK, for example, either a corresponding flag can be set in the control unit or a signal can be output to a user of the motor vehicle. The signal is, in particular, an optical and / or acoustic signal.
Im Folgenden wird die vorliegende Erfindung unter Bezugnahme auf die Zeichnungen an Hand eines Ausführungsbeispiels detailliert beschrieben. Es zeigen: Fig. 1 eine schematische Darstellung eines Abgassystems einer Brennkraftmaschine und In the following, the present invention will be described in detail with reference to the drawings with reference to an embodiment. 1 is a schematic representation of an exhaust system of an internal combustion engine and
Fig. 2 einen schematischen Verfahrensablauf eines erfindungsgemäßen Diagnoseverfahrens eines Rußsensors. 2 shows a schematic process sequence of a diagnostic method according to the invention of a soot sensor.
Figur 1 zeigt ein Abgassystem 1 einer Brennkraftmaschine 3. Die Brennkraftmaschine 3 ist beispielsweise ein Dieselmotor. Das Abgassystem 1 ist insbesondere Teil eines Kraftfahrzeugs (nicht dargestellt). Die Strömungsrichtung des Abgases aus der Brennkraftmaschine 3 ist mit Hilfe des Pfeils 22 dargestellt. An der Brennkraftmaschine 3 ist eine Abgasleitung 24 angeordnet. In der Abgasleitung 24 befinden sich in Strömungsrichtung des Abgases (Pfeil 22) nach der Brennkraftmaschine 3 ein Katalysator 5 sowie ein Partikelfilter 7. Zur Steuerung der Brennkraftmaschine 3 ist weiterhin eine Steuereinheit 10 vorgesehen, die mittels Signalleitungen 12 mit der Brennkraftmaschine 3 verbunden ist. FIG. 1 shows an exhaust system 1 of an internal combustion engine 3. The internal combustion engine 3 is, for example, a diesel engine. The exhaust system 1 is in particular part of a motor vehicle (not shown). The flow direction of the exhaust gas from the internal combustion engine 3 is shown by the arrow 22. On the internal combustion engine 3, an exhaust pipe 24 is arranged. In the exhaust line 24 are in the flow direction of the exhaust gas (arrow 22) after the internal combustion engine 3, a catalyst 5 and a particulate filter 7. For controlling the internal combustion engine 3, a control unit 10 is further provided, which is connected by means of signal lines 12 to the internal combustion engine 3.
Weiterhin sind in dem Abgassystem 1 mehrere Temperatursenso- ren 14, ein Differenzdrucksensor 16 sowie ein Rußsensor 18 in der Abgasleitung 24 angeordnet. Die Sensoren sind jeweils mittels Signalleitungen 20 mit der Steuereinheit 10 verbun- den. Die Steuereinheit wertet die von den Sensoren 14, 16 und 18 übermittelten Signale aus und gibt entsprechende Steuersignale über die SteuerSignalleitungen 12 an die Brennkraftmaschine 3 aus . Furthermore, several temperature sensors 14, a differential pressure sensor 16 and a soot sensor 18 are arranged in the exhaust gas line 24 in the exhaust system 1. The sensors are each connected to the control unit 10 by means of signal lines 20. the. The control unit evaluates the signals transmitted by the sensors 14, 16 and 18 and outputs corresponding control signals via the control signal lines 12 to the internal combustion engine 3.
Die Temperatursensoren 14 sind in der Abgasleitung hinter dem Katalysator 5, vor dem Partikelfilter 7 und hinter dem Partikelfilter 7 angeordnet. Der Differenzdrucksensor 16 weist eine Messstelle vor dem Partikelfilter 7 sowie eine Messstelle hinter dem Partikelfilter 7 auf. Der Rußsensor 18 ist inThe temperature sensors 14 are arranged in the exhaust pipe behind the catalyst 5, in front of the particle filter 7 and behind the particle filter 7. The differential pressure sensor 16 has a measuring point in front of the particle filter 7 and a measuring point behind the particle filter 7. The soot sensor 18 is in
Strömungsrichtung des Abgases (Pfeil 22) hinter dem Partikelfilter 7 angeordnet. Flow direction of the exhaust gas (arrow 22) behind the particulate filter 7 is arranged.
Nun Bezug nehmend auf Figur 2 wird der erfindungsgemäße Ver- fahrensablauf des Diagnoseverfahrens des Rußsensors 18 beschrieben. Zunächst erfasst ein Temperatursensor 14 in einem Schritt A eine erste Temperatur im Abgassystem 1. Insbesondere handelt es sich hierbei um den Temperatursensor 14 der benachbart zu dem Rußsensor 18 in der Abgasleitung 24 angeord- net ist. Referring now to FIG. 2, the procedure of the diagnostic method of the soot sensor 18 according to the present invention will be described. First, a temperature sensor 14 detects a first temperature in the exhaust system 1 in a step A. In particular, this is the temperature sensor 14 which is arranged adjacent to the soot sensor 18 in the exhaust line 24.
Die Steuereinheit 10 stellt in Schritt B fest, ob die von dem Temperatursensor 14 erfasste erste Temperatur unter 100°C liegt. Auf diese Weise kann beispielsweise ein Kaltstart der Brennkraftmaschine 3 erkannt werden. Liegt die erfasste Temperatur unter 100°C, erfasst der Rußsensor 18 in einem The control unit 10 determines in step B whether the detected by the temperature sensor 14 first temperature is below 100 ° C. In this way, for example, a cold start of the internal combustion engine 3 can be detected. If the detected temperature is below 100 ° C, the soot sensor 18 detects in one
Schritt C einen ersten Messwert. Die Steuereinheit 10 vergleicht den ersten Messwert in einem Schritt D mit einem vorgebbaren Grenzwert. Der vorgebbare Grenzwert liegt beispiels- weise in der Mitte des Messbereichs des Rußsensors oder bei zwei Drittel oder Dreiviertel des Messbereichs des Rußsensors. Überschreitet der erste Messwert den vorgebbaren Grenzwert, dann stellt die Steuereinheit 10 in Schritt E fest, dass der Rußsensor in Ordnung ist. Step C a first measured value. The control unit 10 compares the first measured value in a step D with a predefinable limit value. The predefinable limit value is, for example, in the middle of the measuring range of the soot sensor or at two thirds or three quarters of the measuring range of the soot sensor. If the first measured value exceeds the predefinable limit value, then the control unit 10 determines in step E that the soot sensor is in order.
In einem Schritt F wird eine zweite Temperatur im Abgassystem erfasst. Dies geschieht vorzugsweise durch denselben Tempera- tursensor 14, mit dem auch die erste Temperatur erfasst wurde. In Schritt G stellt die Steuereinheit 10 fest, ob die er- fasste zweite Temperatur über 100°C liegt. Ist dies der Fall, dann wird in Schritt H ein zweiter Messwert mit dem Rußsensor 18 erfasst. Die Steuereinheit 10 vergleicht in Schritt I den erfassten zweiten Messwert mit dem vorgebbaren Grenzwert und stellt in Schritt J fest, dass der Rußsensor in Ordnung ist, wenn der zweite Messwert den vorgebbaren Grenzwert unterschreitet. Insbesondere nach einem Kaltstart der Brennkraft- maschine 3 und wenn der Rußsensor 18 in Schritt E als in Ordnung erkannt wurde, werden die Schritte F und G so lange wiederholt, bis die Temperatur im Abgassystem über 100°C liegt. In a step F, a second temperature in the exhaust system is detected. This is preferably done by the same temperature tursensor 14, with which also the first temperature was detected. In step G, the control unit 10 determines whether the detected second temperature is above 100 ° C. If this is the case, then in step H a second measured value is detected with the soot sensor 18. The control unit 10 compares the detected second measured value with the predefinable limit value in step I and determines in step J that the soot sensor is in order if the second measured value falls below the predefinable limit value. In particular, after a cold start of the internal combustion engine 3 and if the soot sensor 18 was detected as being OK in step E, steps F and G are repeated until the temperature in the exhaust system exceeds 100 ° C.
In Schritt K wird eine dritte Temperatur erfasst. Die Steuer- einheit 10 stellt in Schritt L fest, ob die erfasste dritte Temperatur über 100°C liegt und stellt anschließend in In step K, a third temperature is detected. The control unit 10 determines in step L whether the detected third temperature is above 100 ° C and then sets in
Schritt N einen Betriebszustand der Brennkraftmaschine fest, wenn die Temperatur über 100 °C liegt. Insbesondere wenn der in Schritt N festgestellte Betriebszustand der Brennkraftma- schine 3 Volllast ist oder im oberen Drittel eines Drehzahlenbereichs der Brennkraftmaschine liegt, erfolgt in Schritt N das Erfassen eines dritten Messwerts mit dem Rußsensor 18. Der dritte Messwert wird mit dem vorgebbaren Grenzwert in Schritt 0 verglichen. In Abhängigkeit davon, ob der vorgebba- re Grenzwert unterschritten (Ol) oder überschritten (02) wird, stellt die Steuereinheit fest, dass ein Partikelfilter im Abgassystem in Ordnung (Ol) oder defekt ist (02) . Step N determines an operating condition of the internal combustion engine when the temperature is over 100 ° C. In particular, if the operating state of the internal combustion engine 3 determined in step N is full load or is in the upper third of a rotational speed range of the internal combustion engine, then in step N, a third measured value is acquired by the soot sensor 18. The third measured value becomes the predefinable limit value in step 0 compared. Depending on whether the presettable limit value is undershot (Ol) or exceeded (02), the control unit determines that a particulate filter in the exhaust system is in order (Ol) or faulty (02).
Um das Verfahren weiter zu verbessern und auch während eines länger anhaltenden Betriebs der Brennkraftmaschine 3 eine Diagnose des Rußsensors 18 durchzuführen, wird in Schritt P ein Freibrennvorgang des Partikelfilters 7 im Abgassystem 1 festgestellt. Anschließend wird in Schritt Q ein vierter Messwert mit dem Rußsensor 18 erfasst und in Schritt R mit dem vorgeb- baren Grenzwert verglichen. Überschreitet der vierte Messwert den vorgebbaren Grenzwert, dann wird in Schritt S festgestellt, dass der Rußsensor 18 in Ordnung ist. In order to further improve the method and also to carry out a diagnosis of the soot sensor 18 during a prolonged operation of the internal combustion engine 3, a free-burning process of the particulate filter 7 in the exhaust system 1 is determined in step P. Subsequently, in step Q, a fourth measured value is detected with the soot sensor 18 and compared in step R with the predeterminable limit value. If the fourth measured value exceeds the predefinable limit value, then it is determined in step S that the soot sensor 18 is in order.

Claims

Diagnoseverfahren eines Rußsensors, der in einem Abgassystem einer Brennkraftmaschine angeordnet ist, wobei das Verfahren die folgenden Schritte umfasst: A diagnostic method of a soot sensor disposed in an exhaust system of an internal combustion engine, the method comprising the steps of:
a) Erfassen (A) einer ersten Temperatur im Abgassystem, b) Feststellen (B), ob die erfasste erste Temperatur unter 100 °C liegt, wenn ja: a) detecting (A) a first temperature in the exhaust system, b) determining (B) whether the detected first temperature is below 100 ° C, if so:
c) Erfassen (C) eines ersten Messwerts mit dem Rußsensor, der in dem Abgassystem angeordnet ist, c) detecting (C) a first measured value with the soot sensor disposed in the exhaust system,
d) Vergleichen (D) des ersten Messwerts mit einem vorgebbaren Grenzwert und, d) comparing (D) the first measured value with a predefinable limit value and,
e) wenn der erste Messwert den vorgebbaren Grenzwert überschreitet, Feststellen (E), dass der Rußsensor in Ordnung ist. e) if the first reading exceeds the specifiable limit, determining (E) that the soot sensor is OK.
Diagnoseverfahren eines Rußsensors gemäß Anspruch 1, das die weiteren Schritte aufweist: A diagnostic method of a soot sensor according to claim 1, comprising the further steps of:
f) Erfassen (F) einer zweiten Temperatur im Abgassystem, g) Feststellen (G), ob die erfasste zweite Temperatur über 100 °C liegt, wenn ja: f) detecting (F) a second temperature in the exhaust system, g) determining (G) whether the detected second temperature is above 100 ° C, if so:
h) Erfassen (H) eines zweiten Messwerts mit dem Rußsensor , h) detecting (H) a second measured value with the soot sensor,
i) Vergleichen (F) des zweiten Messwerts mit dem vorgebbaren Grenzwert und, i) comparing (F) the second measured value with the predefinable limit value and,
j) wenn der zweite Messwert den vorgebbaren Grenzwert unterschreitet, Feststellen ( J) , dass der Rußsensor in Ordnung ist. j) if the second reading falls below the predeterminable limit, determining (J) that the soot sensor is OK.
Diagnoseverfahren eines Rußsensors gemäß einem der vorhergehenden Ansprüche, das die weiteren Schritte aufweist: Diagnostic method of a soot sensor according to one of the preceding claims, comprising the further steps:
k) Erfassen (K) einer dritten Temperatur, k) detecting (K) a third temperature,
1) Feststellen (L), ob die erfasste dritte Temperatur über 100 °C liegt, wenn ja:  1) Determining (L) whether the detected third temperature is above 100 ° C, if so:
m) Feststellen (11) eines Betriebszustands der Brennkraftmaschine, n) Erfassen (N) eines dritten Messwerts mit dem Rußsensor , m) determining (11) an operating state of the internal combustion engine, n) detecting (N) a third measured value with the soot sensor,
o) Vergleichen (O)des dritten Messwerts mit dem vorgebbaren Grenzwert und, o) comparing (O) the third measured value with the predefinable limit value and,
01) bei Unterschreiten des vorgebbaren Grenzwerts, Feststellen (Ol), dass ein Partikelfilter im Abgassystem in Ordnung ist, oder,  01) falls below the predefinable limit, determining (oil) that a particulate filter in the exhaust system is in order, or
02) bei Überschreiten des vorgebbaren Grenzwerts, Feststellen (02), dass ein Partikelfilter im Abgassystem defekt ist.  02) if the predefinable limit value is exceeded, (02) that a particulate filter in the exhaust system is defective.
Diagnoseverfahren eines Rußsensors gemäß einem der vorhergehenden Ansprüche, das die weiteren Schritte aufweist: Diagnostic method of a soot sensor according to one of the preceding claims, comprising the further steps:
p) Feststellen (P) eines Freibrennvorgangs des Partikelfilters im Abgassystem, anschließend p) Detecting (P) a burn-off process of the particulate filter in the exhaust system, then
q) Erfassen (Q) eines vierten Messwerts mit dem Rußsensor , q) detecting (Q) a fourth measured value with the soot sensor,
r) Vergleichen (R) des vierten Messwerts mit dem vorgebbaren Grenzwert und, r) comparing (R) the fourth measured value with the predefinable limit value and,
s) wenn der vierte Messwert den vorgebbaren Grenzwert überschreitet, Feststellen (S), dass der Rußsensor in Ordnung ist. s) if the fourth reading exceeds the specifiable limit, determining (S) that the soot sensor is OK.
Diagnoseverfahren eines Rußsensors gemäß einem der vorhergehenden Ansprüche, das in einer Steuereinheit eines Kraftfahrzeugs durchgeführt wird, insbesondere in einem Kraftfahrzeug mit Dieselmotor. Diagnostic method of a soot sensor according to one of the preceding claims, which is carried out in a control unit of a motor vehicle, in particular in a motor vehicle with a diesel engine.
EP11702962A 2010-02-02 2011-02-01 Diagnostic method for a soot sensor Withdrawn EP2531706A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102010006708A DE102010006708B4 (en) 2010-02-02 2010-02-02 Diagnostic procedure of a soot sensor
PCT/EP2011/051351 WO2011095466A1 (en) 2010-02-02 2011-02-01 Diagnostic method for a soot sensor

Publications (1)

Publication Number Publication Date
EP2531706A1 true EP2531706A1 (en) 2012-12-12

Family

ID=43873541

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11702962A Withdrawn EP2531706A1 (en) 2010-02-02 2011-02-01 Diagnostic method for a soot sensor

Country Status (4)

Country Link
US (1) US20130090866A1 (en)
EP (1) EP2531706A1 (en)
DE (1) DE102010006708B4 (en)
WO (1) WO2011095466A1 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8490476B2 (en) 2011-03-08 2013-07-23 Ford Global Technologies, Llc Method for diagnosing operation of a particulate matter sensor
DE102011086118B4 (en) * 2011-11-10 2014-07-10 Continental Automotive Gmbh Method and system for an exhaust particulate filter
JP6409452B2 (en) * 2014-09-26 2018-10-24 いすゞ自動車株式会社 Diagnostic equipment
DE102014220846A1 (en) * 2014-10-15 2016-04-21 Continental Automotive Gmbh Method and device for self-diagnosis of a arranged in the exhaust line of an internal combustion engine particle sensor
DE102015215848B4 (en) * 2015-08-19 2019-09-05 Continental Automotive Gmbh Method for monitoring the function of an electrostatic soot sensor
US11828210B2 (en) 2020-08-20 2023-11-28 Denso International America, Inc. Diagnostic systems and methods of vehicles using olfaction
US11881093B2 (en) 2020-08-20 2024-01-23 Denso International America, Inc. Systems and methods for identifying smoking in vehicles
US11636870B2 (en) 2020-08-20 2023-04-25 Denso International America, Inc. Smoking cessation systems and methods
US11760170B2 (en) 2020-08-20 2023-09-19 Denso International America, Inc. Olfaction sensor preservation systems and methods
US11813926B2 (en) 2020-08-20 2023-11-14 Denso International America, Inc. Binding agent and olfaction sensor
US11932080B2 (en) 2020-08-20 2024-03-19 Denso International America, Inc. Diagnostic and recirculation control systems and methods
US11760169B2 (en) 2020-08-20 2023-09-19 Denso International America, Inc. Particulate control systems and methods for olfaction sensors

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004007634A1 (en) * 2004-02-17 2005-09-08 Siemens Ag Method and device for monitoring the particle concentration in a gas stream
DE102005029219A1 (en) * 2005-06-22 2006-12-28 Heraeus Sensor Technology Gmbh Soot deposit measuring method, for use in motor vehicle exhaust area, involves determining separations of soot in inter digital condenser structure or heating conductor by change of electrical or thermal measured value of structure
US20090090622A1 (en) * 2007-10-04 2009-04-09 Ripley Eugene V System and method for particulate sensor diagnostic
DE102008040593A1 (en) * 2008-03-03 2009-09-10 Robert Bosch Gmbh Method for determining measure of water entry into exhaust duct of internal combustion engine, involves determining measure of water entry according to measure of supplied heat energy by heating element of exhaust sensor
JP2010275917A (en) * 2009-05-28 2010-12-09 Honda Motor Co Ltd Failure determination device for particulate matter detection means
US20110047978A1 (en) * 2009-09-02 2011-03-03 Ford Global Technologies, Llc Method for evaluating degradation of a particulate matter sensor
EP2320219A1 (en) * 2009-11-09 2011-05-11 Delphi Technologies, Inc. Method and system for diagnostics of a particulate matter sensor
EP2492481A1 (en) * 2011-02-22 2012-08-29 Delphi Technologies Holding S.à.r.l. Soot sensor functional capability monitoring

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10247977A1 (en) * 2002-10-15 2004-04-29 Robert Bosch Gmbh Method and system for checking the functionality of a particle detector
JP4501877B2 (en) * 2006-03-14 2010-07-14 株式会社デンソー Control device for internal combustion engine
DE102006055520A1 (en) * 2006-11-24 2008-05-29 Robert Bosch Gmbh Device and method for checking the functionality or plausibility of a sensor based on an interdigital electrode system sensor and a sensor for detecting particles in a gas stream and its use
DE102007046097B4 (en) * 2007-09-26 2020-03-26 Robert Bosch Gmbh Method for self-diagnosis of a sensor element for the detection of particles in a gas stream
DE102007047081A1 (en) * 2007-10-01 2009-04-02 Robert Bosch Gmbh Method for detecting a degree of poisoning of a particle sensor and particle sensor
DE102008015256A1 (en) * 2008-03-20 2009-10-01 Continental Automotive Gmbh Diagnostic method and diagnostic system for a particle filter of an internal combustion engine, in particular for a soot filter in a diesel motor vehicle
DE102009001064A1 (en) * 2009-02-23 2010-08-26 Robert Bosch Gmbh Method for determining measure for water drop entry into exhaust gas channel of internal combustion engine, involves comparing rise of sensor signal with threshold value, and providing measure for water drop entry after exceeding value
US8707935B2 (en) * 2009-10-28 2014-04-29 Ford Global Technologies, Llc Exhaust gas recirculation system with a NOx sensor

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004007634A1 (en) * 2004-02-17 2005-09-08 Siemens Ag Method and device for monitoring the particle concentration in a gas stream
DE102005029219A1 (en) * 2005-06-22 2006-12-28 Heraeus Sensor Technology Gmbh Soot deposit measuring method, for use in motor vehicle exhaust area, involves determining separations of soot in inter digital condenser structure or heating conductor by change of electrical or thermal measured value of structure
US20090090622A1 (en) * 2007-10-04 2009-04-09 Ripley Eugene V System and method for particulate sensor diagnostic
DE102008040593A1 (en) * 2008-03-03 2009-09-10 Robert Bosch Gmbh Method for determining measure of water entry into exhaust duct of internal combustion engine, involves determining measure of water entry according to measure of supplied heat energy by heating element of exhaust sensor
JP2010275917A (en) * 2009-05-28 2010-12-09 Honda Motor Co Ltd Failure determination device for particulate matter detection means
US20110047978A1 (en) * 2009-09-02 2011-03-03 Ford Global Technologies, Llc Method for evaluating degradation of a particulate matter sensor
EP2320219A1 (en) * 2009-11-09 2011-05-11 Delphi Technologies, Inc. Method and system for diagnostics of a particulate matter sensor
EP2492481A1 (en) * 2011-02-22 2012-08-29 Delphi Technologies Holding S.à.r.l. Soot sensor functional capability monitoring

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2011095466A1 *

Also Published As

Publication number Publication date
US20130090866A1 (en) 2013-04-11
DE102010006708B4 (en) 2013-01-17
WO2011095466A1 (en) 2011-08-11
DE102010006708A1 (en) 2011-08-04

Similar Documents

Publication Publication Date Title
DE102010006708B4 (en) Diagnostic procedure of a soot sensor
DE102007059523B4 (en) Method and device for diagnosing a particulate filter
DE112008001652B4 (en) Sensor rationality diagnostic
DE102013104697B4 (en) Diagnostic procedure for a soot sensor
EP1925926B1 (en) Device and method for monitoring the operational capability or validation of a sensor based on an electrode system
DE102007014761B4 (en) Method for operating a collecting particle sensor and device for carrying out the method
DE112011104817B4 (en) Internal combustion engine controller
DE102005040790A1 (en) Integrated particle sensor operation, e.g. resistive particle sensor, for use in motor vehicle, involves determining exhaust gas flow rate in sensor, and considering cross sensitivity of sensor in comparison with different gas flows
DE102014209840A1 (en) Method and device for diagnosing a particulate filter
DE102009000286A1 (en) Monitoring a particle limit in the exhaust gas of an internal combustion engine
DE102013104693A1 (en) Emission control system for an internal combustion engine
DE102010027975A1 (en) Method and device for self-diagnosis of an exhaust gas probe
WO2018177897A1 (en) Method and computer program product for diagnosing a particle filter
DE102006029990A1 (en) Particle filter diagnosis method for internal combustion engine of motor vehicle, involves determining particle filter-efficiency factor based on upstream-particle flow that arises upstream before particle filter and downstream after filter
DE102011002502A1 (en) Method for diagnosing an exhaust gas sensor and device for carrying out the method
DE10218218A1 (en) Device and method for determining a malfunction of a filter
DE102011089503A1 (en) Diagnostic procedure for particulate filter arranged in effluent stream of combustion engine, involves comparing detected particle mass concentration with selected particle mass concentration threshold value
DE102009058698B4 (en) Determining the efficiency of a particulate filter by measuring the pressure drop across an additional particulate filter
DE102010028852B4 (en) Method and device for diagnosing an exhaust gas purification system for an internal combustion engine
DE102009001064A1 (en) Method for determining measure for water drop entry into exhaust gas channel of internal combustion engine, involves comparing rise of sensor signal with threshold value, and providing measure for water drop entry after exceeding value
WO2018130459A1 (en) Method and device for the load diagnosis of a particle filter
DE102011122165B4 (en) Method for determining a soot particle filter efficiency of a soot particle filter
DE102016101259B4 (en) Particle number estimation system
DE102012001044A1 (en) Method for determining operability of resistive soot sensor for monitoring particulate filter in motor car, involves outputting notification if change in signal falls below threshold value, where notification indicates malfunction of sensor
DE102010003198A1 (en) Method for monitoring exhaust gas sensor in exhaust duct of internal combustion engine, particularly for monitoring resistive or capacitive particle sensor, involves determining modeled temperature of exhaust gas 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: 20120903

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

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

Effective date: 20150105

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20150516