Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
  • G01N27/416—Systems
  • G01N27/4163—Systems checking the operation of, or calibrating, the measuring 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
  • F02D41/14—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
• • 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
  • G01M15/10—Testing internal-combustion engines by monitoring exhaust gases or combustion flame
  • G01M15/102—Testing internal-combustion engines by monitoring exhaust gases or combustion flame by monitoring exhaust gases
  • G01M15/104—Testing internal-combustion engines by monitoring exhaust gases or combustion flame by monitoring exhaust gases using oxygen or lambda-sensors
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
  • G01N27/403—Cells and electrode assemblies
  • G01N27/406—Cells and probes with solid electrolytes
  • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
  • G01N27/409—Oxygen concentration cells
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
  • G01N27/403—Cells and electrode assemblies
  • G01N27/406—Cells and probes with solid electrolytes
  • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
  • G01N27/41—Oxygen pumping cells
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
  • G01N27/416—Systems
  • G01N27/417—Systems using cells, i.e. more than one cell and probes with solid electrolytes
  • G01N27/4175—Calibrating or checking the analyser
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
• • 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
  • F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
  • F02D41/26—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using computer, e.g. microprocessor
  • F02D41/28—Interface circuits
  • F02D2041/281—Interface circuits between sensors and control unit
• • 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
  • F02D41/1454—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 an oxygen content or concentration or the air-fuel ratio
  • F02D41/1456—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 an oxygen content or concentration or the air-fuel ratio with sensor output signal being linear or quasi-linear with the concentration of oxygen
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
  • G01N27/416—Systems
  • G01N27/417—Systems using cells, i.e. more than one cell and probes with solid electrolytes
  • G01N27/419—Measuring voltages or currents with a combination of oxygen pumping cells and oxygen concentration cells
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/0004—Gaseous mixtures, e.g. polluted air
  • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
  • G01N33/007—Arrangements to check the analyser
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/005—Testing of electric installations on transport means
  • G01R31/006—Testing of electric installations on transport means on road vehicles, e.g. automobiles or trucks
  • G01R31/007—Testing of electric installations on transport means on road vehicles, e.g. automobiles or trucks using microprocessors or computers

Definitions

• the invention relates to a method for checking the fault detection of a control device of an internal combustion engine in the event of a malfunction of a connected one
• a broadband lambda probe wherein the check is performed with a fault simulator located between the broadband lambda probe and the controller, and wherein the fault simulator selectively modifies electrical signals exchanged between the broadband lambda probe and the controller to simulate broadband lambda probe errors.
• the invention further relates to a fault simulator for checking the fault detection of a control unit of an internal combustion engine in the event of a malfunction of a connected broadband lambda probe, the fault simulator being arranged to simulate broadband lambda probe errors between the broadband lambda probe and the control unit.
• lambda sensors are used in modern internal combustion engines for determining the composition of the exhaust gas and for controlling the internal combustion engine.
• Lambda sensors determine the oxygen content of the exhaust gas, which is used to control the internal combustion engine supplied air-fuel mixture and thus the Abgaslamb- before a catalyst.
• the air and fuel supply of the internal combustion engine is controlled via a lambda control loop in such a way that an exhaust gas aftertreatment by in the exhaust passage of the internal combustion engine is provided.
• Catalyst optimal composition of the exhaust gas is achieved.
• gasoline engines is usually on a lambda of 1, ie a stoichiometric ratio of air to fuel regulated. The pollutant emission of the internal combustion engine can be minimized.
• an internal combustion engine can also be regulated for lean operation with excess air.
• the sensor element of a broadband lambda probe has an opening on the surface through which exhaust gas enters.
• the inlet opening is followed by a porous layer, through which the exhaust gas diffuses into a cavity.
• This cavity is separated from the outer exhaust gas by an oxygen ion conducting electrolyte material.
• Both on the outside of the electrolyte and on the side of the cavity are electrodes which are connected via cable with plug contacts.
• the intermediate electrolyte is called the pumping cell.
• a reference gas with a certain constant oxygen concentration is located inside the sensor element, separated from the cavity by the same electrolyte material.
• In contact with the reference gas is another electrode, which is also connected to a plug contact.
• the electrolyte between this and the cavity side electrode is referred to as a measuring cell.
• an electrical voltage referred to below as the Nernst voltage UNO, is applied across the measuring cell, which is determined by the concentration of oxidizing and reducing exhaust gas components in the cavity and in the reference gas. Since the concentration in the reference gas is known and invariable, the dependence on the concentration in the cavity is reduced.
• the Nernst voltage UNO is detected by the electrodes and transmitted to the engine control unit.
• the engine control unit contains a control circuit that keeps the Nernst voltage above the measuring cell at a setpoint value by a so-called pumping current IP is driven through the pumping cell.
• the loop contains a pumping current regulator, which is often referred to as Nernstschreibsregler also according to its control variable. Since the current flow in the electrolyte is due to oxygen ions, the oxygen concentration in the cavity is influenced.
• the diffusion equation results in a linear relationship between the diffusion current, and thus the pumping current, and the oxygen concentration in the exhaust gas.
• the pumping current is now measured in the engine control unit or specified by the engine control unit in dependence on the measured Nernst voltage.
• the pumping current represents a linear signal for the oxygen balance in the exhaust gas.
• a broadband lambda probe If a broadband lambda probe is faulty, this must be detected by the engine control unit.
• today fault simulators are used, which are arranged during the review between the engine control unit and the broadband lambda probe.
• the fault simulator behaves in relation to the engine control unit like a broadband lambda probe with the errors to be checked.
• the engine control unit must detect the relevant error cases without software or application changes.
• One of the error cases to be simulated is a change in the lambda signal of the broadband lambda probe.
• the engine control unit is given a delayed or corrupted signal of the broadband lambda probe.
• the pump current is varied to simulate this error, thus causing changes in the broadband lambda probe and a corresponding reaction in the engine control unit. These changes must be detected and displayed by the diagnostic function in the engine control unit. Changing the pump current to simulate a broadband lambda probe error can make the fault simulation itself too slow. This may cause the engine control unit to respond, for example, to real signal changes that are due to real changes in the composition of the exhaust gas, although the fault simulator should suppress those changes.
• the pumping current is the output and the Nernst voltage UNO is the input signal of the pumping current controller.
• An error simulation by changing the pump current signal acts here first on the broadband lambda probe.
• the Nernst voltage UNO and thus the input signal of the pumping current controller changes.
• the known method for fault simulation via a change in the pumping current has the disadvantage here that the change in the pumping current arrives late in the signal acquisition in the engine control unit. Therefore, real broadband lambda sensor responses to signal changes typically can not be completely suppressed.
• the object of the invention relating to the method is achieved by feeding to the fault simulator a Nernst voltage UN0 meS s of the broadband lambda probe and a pumping current IP M SG of the control unit, that the broadband lambda probe fault simulator a pumping current I Pprobe and the control unit a Nernst voltage U NOsteii feeds and that the fault simulator for the simulation of broadband lambda probe errors changes the Nernst voltage UN0 st eii supplied to the control unit with respect to the Nernst voltage UNO meS s output by the broadband lambda probe.
• the deviation of the Nernst voltage UNO from the Nernst voltage setpoint is the input variable of the pumping current regulator.
• the pumping current IP is the output signal of the pumping current regulator and at the same time the measured variable, which is further processed in the control unit.
• Different error of the broadband lambda probe for example a due to aging effects delayed response or a corrupted Nernstsig- nal, can be simulated by the fact that the error simulator for simulating errors a predetermined Nernst voltage UN s TEII or variable depending on the time Nernst UNOsteii to the control unit.
• the fault simulator predetermines the predetermined Nernst voltage UNOsteii or the Nernst voltage U NOsteii which varies as a function of time independently of or dependent on the Nernst voltage UNO msS s output by the broadband lambda probe.
• the output Nernst voltage UNOsteii can be specified by a provided in the fault simulator ⁇ -controller.
• the pump current I Pprobe output to the broadband lambda probe corresponds to the pumping current IP M SG output by the motor control unit or
• the choice of the output to the broadband lambda probe pump current I Psonde can be made depending on the error to be simulated.
• Corresponds to the pump current IP So hands to the pump current I PMSG output by the engine control system, it can be fed through from the engine control by the fault simulator to the broadband lambda probe. If the pumping current I Pprobe is predetermined by the fault simulator, the pumping current I PMSG provided by the motor control can be lowered in the fault simulator.
• the pump current I Psonde outputted to the broadband lambda probe is predefined by the fault simulator as a function of the pumping current I PMSG output by the control unit, it can be provided that the PMSG is predetermined by the fault simulator and sent to the broadband lambda probe as a function of the pumping current I PMSG output pump current I Pprobe is greater or smaller and / or delayed in time compared to the pump current I PMSG is specified.
• the fault simulator for an internal resistance measurement with respect to the control unit simulates a load and provides a corresponding voltage signal.
• the problem of the invention relating to the fault simulator is solved by supplying to the fault simulator a Nernst voltage UN0 meS s of the broadband lambda probe and a pumping current IP M SG of the control unit, that the broadband lambda probe a pumping current I Psonde and the controller a Nernst mecanic UN0 s tei is supplied by the fault simulator and that the fault simulator is adapted to the Nernst voltage UN0 s teii supplied to the controller compared to that of the broadband
• the fault simulator thus makes it possible to carry out the method described.
• FIG. 1 shows a fault simulator for checking the fault detection of a control unit.
• FIG. 1 shows a fault simulator 12 for checking the fault detection of a control unit 14.
• the fault simulator 12 is connected between a broadband lambda probe 10 and a control unit 14.
• the fault simulator 12 is supplied with a Nernst voltage U NOmess 1 1 of the broadband lambda probe 10 and a pumping current I PMSG 16 of the control unit 14.
• the fault simulator 12 supplies the broadband lambda probe 10 with a pumping current I Pprobe 15 and the control unit 14 with a Nernst voltage UNO S 13.
• the signals are represented by corresponding arrows, the number of signal lines shown is limited to the Necessary for the representation of the invention number.
• Fault simulators 12 are used to test certain fault scenarios in broadband lambda probes 10.
• the fault simulator 12 is connected between the broadband lambda probe 10 and the associated control unit 14.
• the fault simulator 12 behaves in relation to the control unit 14 like a broadband lambda probe 10 with the errors to be checked, while the broadband lambda probe 10 continues to operate.
• the control unit 14 must recognize the errors specified by the fault simulator without software or application changes.
• An error case to be simulated is a change in the lambda signal of the broadband lambda probe 10, so that the control unit 14 is simulated a delayed or falsified lambda signal.
• the pump current IP is changed in order to bring about changes in the broadband lambda probe 10. These changes must be detected by the control unit 14 through a diagnostic function.
• the variation of the pumping current IP to simulate a broadband lambda probe 10 fault may cause the fault simulation itself to be too slow. This may result in the controller 14 causing the controller to, for example, respond to real signal changes with a corresponding real change in the exhaust gas composition, although the fault simulator 12 should suppress this change.
• the fault simulation is performed by the fault simulator 12 on the basis of the Nernst voltage UNO.
• the fault simulator 12 also interrupts the supply of the output from the broadband lambda probe 10 Nernstschreib UN0 meSs 1 1 to the controller 14 and outputs a correspondingly changed Nernstschreib UN0 ste ii 13 and the controller 14 from.
• the fault simulator 12 can thus cause a change in the pumping current I PMSG 16 by the Nernstschreib UN0 ste ii 13 is changed accordingly. Since this change takes place before the regulation itself, no unwanted reactions to changes in the pumping current signal due to a change in the real exhaust gas are visible in the control unit 14.
• the control unit 14 can arbitrarily set the output Nernst voltage UN0 ste ii 13 and in particular a time change of the Nernst voltage UN0 ste ii 13. This can be done by a ⁇ -controller provided in the fault simulator 12, for example, depending on the measured Nernst voltage UN0 meSs or independently.
• the pumping current I PMSG 16 then calculated and output by the control unit 14 can pass directly through the fault simulator 12 to the broadband lambda probe 10 to get redirected.
• the pumping current IP M SG 6 can be lowered in the fault simulator 12 without affecting the broadband lambda probe 10.
• the broadband lambda probe 10 is supplied with a pumping current I Pprobe 15, which in the fault simulator 12 based on the Nernstpressive UN0 meS s 1 1 was calculated.
• a third possibility is to manipulate the pumping current I Pprobe 15 as a function of the pumping current IP M SG 16 and forward it to the broadband lambda probe 10.
• the pumping current I Pprobe 15 can be selected larger, smaller or delayed with respect to the pumping current IP M SG 16.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Physics & Mathematics (AREA)
• Physics & Mathematics (AREA)
• Combustion & Propulsion (AREA)
• Electrochemistry (AREA)
• Molecular Biology (AREA)
• General Health & Medical Sciences (AREA)
• Analytical Chemistry (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Biochemistry (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Emergency Medicine (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Testing Electric Properties And Detecting Electric Faults (AREA)
• Testing Of Engines (AREA)
• Testing And Monitoring For Control Systems (AREA)

Applications Claiming Priority (2)

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• 2012
  • 2012-07-25 DE DE102012213068.3A patent/DE102012213068A1/de active Pending
• 2013
  • 2013-07-09 WO PCT/EP2013/064454 patent/WO2014016109A1/de active Application Filing
  • 2013-07-09 CN CN201380039311.2A patent/CN104471411B/zh active Active
  • 2013-07-09 IN IN8552DEN2014 patent/IN2014DN08552A/en unknown
  • 2013-07-09 US US14/417,310 patent/US9880127B2/en active Active
  • 2013-07-09 KR KR20157004609A patent/KR20150038248A/ko not_active Application Discontinuation
  • 2013-07-09 JP JP2015522038A patent/JP6092385B2/ja active Active
  • 2013-07-09 EP EP13736540.9A patent/EP2877865A1/de not_active Withdrawn

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