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
  • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
  • F02D41/1446—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 exhaust temperatures
• • 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
  • G01—MEASURING; TESTING
  • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
  • G01K15/00—Testing or calibrating of thermometers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/04—Engine intake system parameters
  • F02D2200/0414—Air temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/08—Exhaust gas treatment apparatus parameters
  • F02D2200/0802—Temperature of the exhaust gas treatment apparatus
• • 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
  • F02D41/04—Introducing corrections for particular operating conditions
  • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/40—Engine management systems

Definitions

• the invention relates to a method and a device for monitoring a sensor.
• DE 199 06 287 discloses a method and a device for controlling an internal combustion engine with an exhaust gas aftertreatment system.
• a particle filter is used that filters out particles contained in the exhaust gas.
• the state of the exhaust gas aftertreatment system must be known for precise control of the internal combustion engine and of the exhaust gas aftertreatment system.
• Sensors are used, among other things, to record the state of the exhaust gas aftertreatment system. In particular, sensors are used that provide temperature values that characterize the temperature before, after and / or in the exhaust gas aftertreatment system.
• Method for monitoring a sensor of an exhaust gas aftertreatment system in particular one Temperature sensor.
• a first signal of a first sensor to be monitored is compared with a second signal of a second sensor and an error is detected when at least the two signals differ from one another by more than a predeterminable value is simple and reliable monitoring possible from sensors of an exhaust gas aftertreatment system.
• Temperature sensors are preferably monitored using the procedure. The procedure is also for other sensors that control the
• Exhaust gas treatment system can be used. This preferably applies to sensors for detecting the state of the exhaust gas aftertreatment system and / or for pressure, temperature and / or air volume sensors.
• the first signal characterizes the temperature of the exhaust gases upstream of an exhaust aftertreatment system, in an exhaust aftertreatment system and / or after one
• these signals are compared with a second signal which characterizes the temperature of the gases which are fed to the internal combustion engine, the oxidation catalytic converter or the particle filter. These signals are particularly suitable, since in certain operating states this comparison signal assumes almost the same values as the signals to be monitored.
• FIG. 1 shows a block diagram of the device according to the invention
• FIG. 2 shows a flow diagram to illustrate the procedure according to the invention.
• Example of a self-igniting internal combustion engine is shown, in which the fuel metering is controlled by a so-called common rail system.
• the procedure according to the invention is not restricted to these systems. It can also be used in other internal combustion engines.
• the exhaust gas aftertreatment means 110 is arranged in the exhaust gas line 104, from which the cleaned exhaust gases reach the surroundings via the line 106.
• the exhaust gas aftertreatment means 110 essentially comprises a so-called pre-catalyst 112 and a filter 114 downstream Pre-catalytic converter 112 and the filter 114, a temperature sensor 124 is arranged, which provides a temperature signal TVF.
• Sensors 120a and 120b are provided in front of the pre-catalytic converter 112 and after the filter 114. These sensors act as a differential pressure sensor 120 and set
• Differential pressure signal DP ready which characterizes the differential pressure between the inlet and outlet of the exhaust gas aftertreatment agent.
• a sensor 126 is arranged in the intake line 102, which detects a signal T1 which characterizes the temperature T1 of the fresh air supplied.
• a sensor 125 supplies a signal TVO, which characterizes the temperature upstream of the exhaust gas aftertreatment system 110.
• the internal combustion engine 100 is metered fuel via a fuel metering unit 140. This measures fuel via injectors 141, 142, 143 and 144 to the individual cylinders of internal combustion engine 100.
• the fuel metering unit is preferably a so-called common rail system.
• a high pressure pump delivers fuel to an accumulator. The fuel reaches the internal combustion engine via the injectors.
• Various sensors 151 are arranged on the fuel metering unit 140, which provide signals that characterize the state of the fuel metering unit.
• a common rail system is, for example, the pressure P in the pressure accumulator.
• Sensors 152 which characterize the state of the internal combustion engine, are arranged on the internal combustion engine 100. This is, for example, a temperature sensor that provides a signal TW that characterizes the engine temperature.
• the output signals of these sensors go to a controller 130, which acts as a first sub-controller 132 and a second partial control 134 is shown.
• the two partial controls preferably form a structural unit.
• the first sub-controller 132 preferably controls the fuel metering unit 140 with control signals AD that influence the fuel metering.
• the first partial control 132 includes a fuel quantity control 136. This supplies a signal ME, which characterizes the quantity to be injected, to the second partial control 134.
• the second sub-controller 134 preferably controls the exhaust gas aftertreatment system and detects the corresponding sensor signals for this purpose. Furthermore, the second sub-controller 134 exchanges signals, in particular via the injected fuel quantity ME, with the first sub-controller 132. Preferably use the two
• the first partial control which is also referred to as motor control 132, controls depending on various conditions
• the exhaust gas aftertreatment means 110 filter them out of the exhaust gas. Through this filtering process, 114 particles collect in the filter. These particles are then in certain operating states, loading states and / or after certain times or counter readings for Amount of fuel or distance burned to clean the filter. For this purpose, it is usually provided that the temperature in the exhaust gas aftertreatment means 110 is increased so that the particles burn in order to regenerate the filter 114.
• the precatalyst 112 is provided for increasing the temperature.
• the temperature is increased, for example, by increasing the proportion of unburned hydrocarbons in the exhaust gas. These unburned hydrocarbons then react in the pre-catalyst 112 and increase its temperature and the temperature of the exhaust gas.
• This temperature increase of the pre-catalytic converter and the exhaust gas temperature requires an increased fuel consumption and should therefore only be carried out when this is necessary, i.e. the filter 114 is loaded with a certain proportion of particles.
• One way of recognizing the loading condition is to determine the differential pressure DP between the inlet and outlet of the
• a central function in the control of the exhaust gas aftertreatment system are the sensors used, in particular the temperature sensors, which are used for the correct control of the exhaust gas
• Exhaust aftertreatment systems are essential. It is not sufficient to test the functionality of the sensors as part of maintenance or a technical check. This applies in particular against the background of the legal requirements for on-board diagnosis of emission-relevant systems.
• the defect of a sensor must be recognized early in order to prevent the permissible emissions from being exceeded and to ensure the functionality of the exhaust gas aftertreatment system. The procedure described below enables a simple check, in particular of the temperature sensors in the exhaust system, and thus ensures the functionality of the
• the procedure according to the invention is described below using the example of temperature sensors. In principle, this procedure can also be used with other sensors, in particular for sensors in the exhaust system. With the procedure according to the invention, all sensors that are based on the internal combustion engine, ie. H. between internal combustion engine and exhaust gas aftertreatment system, sensors in exhaust gas aftertreatment, d. H. between the oxidation catalytic converter and the particle filter and / or sensors after the particle filter. Furthermore, the procedure according to the invention is also possible with other arrangements of the catalysts and / or the particle filter.
• the malfunction of the temperature sensor in the exhaust system is recognized by a
• Control unit available so that no further sensors are necessary.
• FIG. 2 shows an exemplary embodiment of the procedure according to the invention as a flow chart.
• a first one Query 200 checks whether the last start was long enough ago.
• a second query 205 checks whether the internal combustion engine has started to rotate.
• Query 205 preferably checks whether speed N is greater than 0. If this is not the case, step 205 follows again. If the internal combustion engine rotates, a time counter Z is started in step 208 and a query 210 checks whether different temperature signals such as the cooling water temperature TW and / or the temperature of the fresh air quantity T 1 drawn in and / or the
• Ambient temperature which corresponds in a first approximation to the temperature Tl, is less than a threshold value SW. If not, i. H. if one of the temperatures is greater than the threshold value, it is recognized in step 295 that no check is possible. If the temperatures are lower than the threshold value, query 220 follows. In a simplified embodiment it can also be provided that only one of the temperature values is checked.
• the query 220 checks whether the amount of the difference between these two temperature values is less than a threshold value SW2. If not, i. H. the
• the query 230 checks whether the speed N is greater than a threshold value SN. If this is not the case, step 230 takes place again. If query 230 recognizes that the
• query 240 follows. This query 240 checks whether the time Z since the first rotation of the internal combustion engine is less than a threshold value ST. If this is not the case, it is also recognized that no check is possible. Is the time since the first rotation of the internal combustion engine less than a threshold value, the actual checking of the temperature sensors takes place from step 250.
• a first query 250 checks whether the amount of
• step 280 Difference between the fresh air temperature Tl and the temperature TVO before the exhaust gas aftertreatment system is greater than a threshold value GW1. If this is the case, an error is recognized in step 280. If this is not the case, it is checked whether the amount of the difference between the ambient temperature T1 and the temperature in the exhaust gas aftertreatment system TVF is greater than a threshold value GW2. If this is the case, then an error is also detected in step 280. If this is not the case, query 270 checks whether the amount of the difference between the temperature signal TVO, the temperature in front of the exhaust gas aftertreatment system and the temperature TVF in the exhaust gas aftertreatment system is greater than a threshold value GW3. If this is the case, errors are also recognized in step 280. If this is not the case, then in step 290 it is recognized that there is no error and the sensors are working properly.
• the procedure described shows the monitoring using the example of a temperature sensor 125 before
• Exhaust gas aftertreatment system and a temperature sensor 124 in the exhaust gas aftertreatment system which is arranged between an oxidation catalyst and a particle filter.
• the procedure described is not limited to this special arrangement of the sensors. It can also be used in other arrangements of sensors and / or catalysts and filters.
• a temperature sensor in particular temperature sensor 125, can be replaced by a sensor in front of the NOx storage catalytic converter.
• further sensors are arranged in the exhaust gas aftertreatment system, in which case these are checked for plausibility both with the ambient temperature and with one another.
• a check is preferably only carried out when there is a cold start. This means that the check is only carried out if the engine has not been operated for a long time. For this purpose, it is checked whether the last start process was long enough ago. This is recognized by means of query 200. A check in this case is prevented because the
• the measured temperatures have changed only slightly, which is due, among other things, to the inertia of the sensors. If the starting process takes too long, this can no longer be guaranteed. It is therefore checked in query 240 whether the start release speed was reached within a predeterminable maximum time. The plausibility check is preferably only carried out when all checks have been carried out. In simplified embodiments, it can also be provided that one or the other query does not take place. If the above conditions apply, the temperature differences between the temperature sensors to be monitored and the intake air temperature as well as the difference between the individual temperature signals to be monitored are formed. In the exemplary embodiment shown, the temperature sensors upstream of the catalytic converter and upstream of the filter are monitored. If the differences are larger than a limit value, an error is recognized. An error-free state is recognized when all temperature sensors display the value of a reference sensor. Instead of the intake air temperature, the ambient air temperature can also be used as a reference sensor.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Exhaust Gas After Treatment (AREA)
• Filtering Of Dispersed Particles In Gases (AREA)
• Measuring Temperature Or Quantity Of Heat (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

Applications Claiming Priority (3)

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• 2001
  • 2001-03-14 DE DE10112139A patent/DE10112139A1/de not_active Withdrawn
• 2002
  • 2002-02-26 JP JP2002572361A patent/JP2004526959A/ja active Pending
  • 2002-02-26 KR KR10-2003-7011630A patent/KR20030087014A/ko active IP Right Grant
  • 2002-02-26 WO PCT/DE2002/000705 patent/WO2002073146A1/de active Application Filing
  • 2002-02-26 US US10/471,903 patent/US6952953B2/en not_active Expired - Fee Related
  • 2002-02-26 EP EP02714070A patent/EP1370840A1/de not_active Withdrawn

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