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
  • F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
• • 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
  • F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
  • F02D41/2425—Particular ways of programming the data
  • F02D41/2429—Methods of calibrating or learning
  • F02D41/2451—Methods of calibrating or learning characterised by what is learned or calibrated
  • F02D41/2474—Characteristics of sensors
• • 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
  • F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
  • F02D41/2425—Particular ways of programming the data
  • F02D41/2429—Methods of calibrating or learning
  • F02D41/2477—Methods of calibrating or learning characterised by the method used for learning
• • 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
  • F02D2200/70—Input parameters for engine control said parameters being related to the vehicle exterior
  • F02D2200/703—Atmospheric pressure
• • 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
  • F02D41/0002—Controlling intake air
  • F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
• • 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
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0047—Controlling exhaust gas recirculation [EGR]
  • F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
• • 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
  • F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
  • F02D41/2425—Particular ways of programming the data
  • F02D41/2429—Methods of calibrating or learning
  • F02D41/2441—Methods of calibrating or learning characterised by the learning conditions
• • 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
  • F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
  • F02D41/2425—Particular ways of programming the data
  • F02D41/2429—Methods of calibrating or learning
  • F02D41/2441—Methods of calibrating or learning characterised by the learning conditions
  • F02D41/2448—Prohibition of learning

Definitions

• the present invention relates to a system and a method for controlling the operation of an internal combustion engine of a motor vehicle.
• the control of the operation of the engine is managed by a set of sensors and actuators according to a set of control laws, called "software strategies", and characterization parameters or calibrations of the engine. All of these laws and parameters can be stored in an electronic control unit or ECU.
• a turbocharger5 comprising a turbine driving a compressor so as to increase the pressure of the air admitted into the engine cylinders.
• the turbine is placed at the outlet of the engine exhaust manifold and is driven by the exhaust gas.
• the power provided by the exhaust gases to the turbine can be modulated by installing a relief valve or by providing vanes with variable geometry on the turbine.
• the compressor is mounted on the same mechanical axis as the turbine. It compresses the air entering the intake manifold.
• the internal combustion engines may be equipped with partial exhaust gas recirculation (EGR) circuits for the Exhaust Gas Recirculation system to reduce the amount of pollutant emissions.
• EGR exhaust gas recirculation
• the control of the operation of the engine is provided electronically to regulate, in particular, the optimal flow rates of air and fuel.
• the enslavement of the actual flow rates with respect to the setpoint flow rates is achieved by the measurements provided by a set of sensors.
• These sensors include the flowmeter which measures the flow of fresh air entering the engine.
• Problems are generally encountered when using flow meters because of dispersions of innumerating measures to their design and use and present from their manufacture. Moreover this dispersion of the results can evolve over time in the form of a drift between real air flow and measured.
• the actual flow into the engine, or engine intake capacity is dispersed from manufacture.
• the control strategies of the engine operation must therefore not only take into account the measured flow rates but also the dispersions of these measured flow rates.
• BOSCH a method for correcting the deviations of the air / fuel mixture ratio from a set value by correction of the air and / or fuel flow.
• French patent application 2,860,268 also discloses a method for controlling the operation of an internal combustion engine by regulating the air flow by means of learning an engine mapping. .
• a patch estimated by mapping as it is described is cumbersome and difficult to put into practice. The number of points to map to obtain an effective correction makes the application of this method difficult to use in a vehicle.
• the present invention relates to a system and a method for compensating in a simple way, without adding additional sensor and for each engine, the dispersion and drift of the fresh air flow measuring means. admitted in a internal combustion engine.
• the subject of the invention is also the conditions and the logic diagram necessary for triggering a procedure for learning the correction of the measured airflow.
• the system for controlling the operation of an internal combustion engine of a motor vehicle that is supercharged with air comprises reducing the drifts and dispersions of a means for measuring the fresh air flow rate based on the comparison between the air flow measured by the flow meter on the one hand and a gas flow estimator entering the engine on the other hand in the absence of exhaust gas recirculation (EGR).
• EGR exhaust gas recirculation
• the flow rate of the gases admitted to the estimated engine and the measured airflow and the standard deviations of the respective dispersions are quantified.
• the intake air flow is equal to the gas flow admitted to the engine.
• the measured air flow rate and the flow rate of the gases admitted into the estimated engine are then compared at different times in the life of the vehicle and a corrective table is derived which makes it possible to establish an airflow correction function.
• the invention also provides an improvement in methods of correcting airflows by correcting the measurement of the airflow rate by learning, such a correction being applicable in the context of the use of the vehicle by the user. final.
• the correction takes place transparently for the user and throughout the life of the vehicle, which ensures a correction adapted to the evolution over time of the engine.
• the standard deviation of the dispersion of the measurements of the incoming air flow rate is determined.
• the estimated optimum flow rate of the gases admitted to the engine is then determined after comparing the standard deviations of the dispersions of the measured air flow and the flow rate of the gases admitted to the estimated engine.
• a function of correction of the measured air flow is calculated according to the discrepancies observed between the measured air flow rate and the estimated optimum flow rate of the gases admitted into the engine, during the learning phases.
• learning of patches is subject to verification of stored learning conditions. Once verified, a trigger signal is sent to the comparison means to calculate the corrections of the measured airflow.
• Verification of the learning conditions is provided by a set of logic gates comparing the information collected by a set of sensors to the reference data.
• the first logic gate makes it possible to ensure that the motor operates in sufficiently stable conditions to guarantee the reliability of the correction process.
• These stability conditions can be restricted to stored temperature and pressure ranges. For example and without limitation, there may be mentioned a motor water temperature range, an external temperature range or an atmospheric pressure range.
• the second door makes it possible to verify that the exhaust redirection valve is closed and that the turbocharger has compensated for this closure by keeping the flow of gases admitted into the engine at a constant level.
• the last door receives the signal from the first door, the means for checking the opening state of the partial recirculation valve of the exhaust gases and the means for comparing the measurement of the admission air flow with the reference value.
• the latter gate triggers the emission of the signal triggering learning if each of the three signals provide a positive response.
• the patches resulting from the comparison between the estimated optimal flow rate of the gases entering the engine and the air flow are stored in a patch table. measured, as well as the corresponding measured airflows, for each learning point.
• the patch table is stored in a non-volatile memory.
• Fixes and correction functions can be defined as additive or multiplicative error corrections.
• the measured airflow is corrected by the corrective function.
• This corrected airflow is then provided to control strategies using fresh air flow measurement to reduce the impact of fresh air dispersions on their operation.
• FIG. 1 schematically illustrates the main elements of a combustion ignition engine, and supercharged air.
• FIG. 2 illustrates, in one embodiment, the logic diagram governing the correction strategy.
• Figure 3 illustrates, in one embodiment, the logic diagram used for the verification of the learning conditions.
• FIG. 1 is shown schematically an internal combustion engine 1 comprising four cylinders l a.
• the fresh air entering the intake manifold of the engine 2 passes through before a compressor 3a of a turbocharger 3.
• the turbocharger 3 is composed of a compressor 3a and a turbine 3b arranged on the same axis.
• the fresh air taken from the outside, symbolized by the arrow F, first passes through an air filter 4, then a flow meter 5, before entering the compressor 3a.
• Compressed air by the compressor 3a crosses, an intake pipe 6 containing a pressure sensor 7 measuring the boost pressure of the engine 1 followed by a three-way valve 8 capable of regulating a partial exhaust gas recirculation flow (EGR valve) before to enter the intake manifold 2.
• EGR valve partial exhaust gas recirculation flow
• the other part of the exhaust gas is fed through the exhaust pipe 12 to the turbine 3b to drive the compressor 3a.
• the exhaust gases pass through the exhaust elbow 13, then an optional catalytic converter for nitrogen oxides 14 and / or an optional particulate filter 15, before being discharged into the exhaust. 16.
• the flow meter 5, the turbocharger 3, the pressure sensor 7 and the EGR valve 8 are connected to the control means 17 via electrical connections 18.
• the control means 17 is electronically connected to non-volatile memory 19.
• the assembly 20 formed by the control means 17 and the non-volatile memory 19 is integrated in an electronic control unit (ECU) referenced 20 which furthermore ensures the management of the operation of the engine 1.
• ECU electronice control unit
• the learning strategy of the table correction and correction of the incoming fresh air flow measurement is shown in figure 2.
• the strategy starts with the measurement of the flow of fresh air admitted by the flowmeter 4, then the estimate of the difference -type of the measurement of the air flow by a calculation means 21.
• an estimation means 22 estimates the flow rate of the gases admitted to the engine followed by a calculation means 23 which calculates the standard deviation on the engine. estimation of the flow rate of gases admitted to the engine.
• the values of the standard deviation of the intake air flow and the flow rate of the gases admitted to the engine are provided by means of calculation 24 which compares these values with a calibration value ( ⁇ ) and calculates the estimated optimum flow rate of the gases entering the engine.
• the correction means 25 calculates the corrections and the function of correction of the measured air flow, according to the flow of air supplied by the flow meter 4, and the estimated optimum flow rate of the gases entering the engine provided by the means of calculation 24, if it has received a learning trigger signal 26 from the learning condition verification means 27.
• the verification means 27 receives the flow rate of the gases admitted to the engine estimated by the estimating means 22 and the flow rate of air measured by the flowmeter 4.
• the logic diagram of the verification means 27 is detailed in FIG. 3.
• correction function calculated by the correction means 25 is supplied to the correction means 28 in parallel with the measured fresh air intake measured by the flowmeter 4 which then calculates the corrected fresh air flow rate.
• the corrected value of the intake air flow is supplied to the ECU 20 for use in the engine operation control strategies.
• the estimated optimum flow rate of the gases admitted to the engine, from the correction means 25, is calculated by comparing the standard deviations of the dispersions of the measured air flow ( ⁇ Q air mes ) and the flow rate of the gases admitted to the estimated engine ( ⁇ Q mo t_est) - For this, we use the function:
• ⁇ ⁇ ⁇ -mot is X-- air my word _ is opti, - *
• the estimated optimum flow rate of the gases admitted to the engine is equal to ⁇ c word _e st _op t ⁇ ⁇ ⁇ c word _est
• the means for verifying the learning conditions is detailed in FIG. 3. It is composed of three logic gates connected on the one hand to the comparison means themselves connected to the different sensors and calculation means and on the other hand to actuators or by learning the fix table.
• a first gate of the "AND" type 29 sees on its inputs signals coming from the comparison means comparing the reference values with the corresponding measurements, namely the stability conditions 30, the environmental conditions 31, as well as the conditions over the elapsed time since the last iteration 32. Its outputs are connected to the second 34 and third gate 37.
• the environmental conditions include the measurement results of a set of sensors (not shown) of temperature and pressure of the conditions outside the vehicle (outside temperature). , atmospheric pressure,) and internal (cooling water temperature, ..)
• a second gate of the "AND” type 34 sees on its inputs signals from the first gate 29 and the comparison means 33 of the flow of gases admitted into the engine 1 with a reference value. Its outputs are connected to the control device 35 of the turbocharger 3 and to the control device 36 of the valve 7.
• This door 33 is only necessary in the case where the engine 1 is equipped with an EGR valve 7 and a turbocharger 3.
• a third gate of the "AND" type 37 sees on its inputs signals coming from the control device 36 of the EGR valve 7, the first gate 29 and the comparison means 38 of the flow rate measured by the flowmeter 4 with a range of stored values. Its output sends a signal 26 to the correction means 25 triggering the learning of the patch table.
• the reference values used by the different comparison means form the learning conditions.
• Closing the EGR valve 7 can lead to a pressure drop at the input of the engine 1 that can move the flow rate of the gases entering the estimated engine from the operating point that triggered the learning.
• specific parameters can be imposed on the supercharging regulation so that the flow of gases admitted to the engine without exhaust gas control remains at maximum identical to the flow rate of gases admitted to the engine with recirculation. Errors in the measurement of fresh air flow can be interpreted mathematically, either as multiplicative factors or as additive factors.
• the patch table stores the measured and corrected airflow torque for each learning point. The average of several measurements of fresh air flow rate and several gas flow calculations allowed in the estimated engine before storing the values. The table thus obtained is stored in a nonvolatile memory 19 making it possible to ensure the durability of the correctives learned during the stopping of the engine 1. The correction factor is then interpolated from the corrective table and the flow rate corrected air.
• the present invention makes it possible to define a system and a method for correcting the dispersions and drifts of the measured fresh air flow, based on a method of learning a corrective table under particular operating conditions of the engine, said conditions being learning.
• a correction function is derived from this table and is used to correct the measurement of the fresh air flow measured.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Analytical Chemistry (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)
• Testing Of Engines (AREA)
• Measuring Volume Flow (AREA)
• Exhaust Gas After Treatment (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2006
  • 2006-10-11 FR FR0654206A patent/FR2907169B1/fr not_active Expired - Fee Related
• 2007
  • 2007-09-27 EP EP07848375A patent/EP2078150B1/de active Active
  • 2007-09-27 DE DE602007007799T patent/DE602007007799D1/de active Active
  • 2007-09-27 WO PCT/FR2007/052037 patent/WO2008043933A1/fr active Application Filing
  • 2007-09-27 AT AT07848375T patent/ATE474134T1/de not_active IP Right Cessation

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