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
  • F02D41/24—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
  • F02D41/2454—Learning of the air-fuel ratio control
• • 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
  • F02D41/248—Methods of calibrating or learning characterised by the method used for learning using a plurality of learned values
• • 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
  • F02D41/2483—Methods of calibrating or learning characterised by the method used for learning restricting learned values
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
  • F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
  • F02D13/0203—Variable control of intake and exhaust valves
  • F02D13/0215—Variable control of intake and exhaust valves changing the valve timing only
  • F02D13/0219—Variable control of intake and exhaust valves changing the valve timing only by shifting the phase, i.e. the opening periods of the valves are constant
• • 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
  • F02D41/2464—Characteristics of actuators
  • F02D41/2467—Characteristics of actuators for injectors

Definitions

• the invention relates to a method, implemented in a heat engine engine control, for limiting a correction carried out by several adaptives on at least one parameter.
• This heat engine is advantageously but not limitatively a controlled ignition engine, in particular a petrol fuel engine or a mixture containing petrol and the correction limitation is advantageously but not limitatively done to limit the correction carried out by the adaptives on the richness of fuel injected into the heat engine.
• the physical behavior of these actuators may differ from the behavior models integrated into the motor control.
• This shift in the models of the actuators in particular those relating to the air intake branch and the fuel injection branch, can lead to richness drifts, therefore to overconsumption or an increase in polluting emissions and can also have an impact on the driving pleasure felt by the driver.
• the richness of a fuel mixture indicates the proportion value between the air and the fuel of the mixture admitted into the combustion chamber of the engine.
• the quality of the combustion depends mainly on this dosage.
• Engine control will therefore have to correct these richness drifts throughout the life of the vehicle. This correction is carried out by a known richness regulation function which permanently corrects the injector control time based on the richness measurement supplied by the richness sensor present at the exhaust.
• This document more particularly describes a method for correcting the richness in the event of exceeding a threshold value, implemented in a heat engine engine control comprising an injection device using a richness setpoint value to control the heat engine.
• the method notably comprises a phase for calculating a difference between the estimated real richness value and the richness setpoint value, and, if the difference exceeds an error threshold, a direct richness correction phase.
• This direct richness correction phase is carried out by iterative learning and updating of the different richness adaptives.
• the adaptives can be of a different nature: we can cite, for example, adaptives on the position models of camshaft phase shifters, or even adaptives on the modeling of physical parameters of the injector (such as for example the static gain or the dead time of the injector control).
• these adaptives are applied to the models under conditions different from those of learning (for example, vis-à-vis the engine water temperature), it may happen that the engine control strategy needs to limit temporarily the level of correction of these adaptive in order to prevent undesired effects of over-correction or under- correction of wealth, and therefore of the risks associated with pollutant emissions and driving pleasure.
• the engine control strategy implements an independent saturation of each of the adaptives, in order to limit the richness correction carried out by the adaptives.
• the saturation value applied to each adaptive by such a method is for example defined as a function of the current operating point of the motor, to try to adapt the limitation to the effects of each adaptive on this current operating point.
• the object of the invention is to overcome the drawbacks of the prior art by proposing a method, implemented in motor control, for limiting a correction carried out by several adaptives on at least one parameter, which is more exhaustive and more precise, and which makes it possible to control the limitation of the parameter at any point of engine operation and to take into account the possible interactions between adaptives, in particular when these adaptives are of a different nature.
• the invention thus relates, in its broadest sense, to a method, implemented in engine control of a vehicle, of limitation of a correction of at least one parameter, said correction being performed by several adaptive devices, the method comprising the following steps:
• the method according to the invention is therefore an engine control function, which assists a known learning function by limiting the correction of a parameter such as the fuel richness carried out by adaptives of this learning function.
• the present invention can of course be adapted to motor control learning functions other than a richness correction learning function.
• the method according to the invention makes it possible to precisely limit the effects of the correction of the parameter by all of the adaptives as a function of the current operating point of the motor.
• the limitation of correction allowed by the method according to the invention is more exhaustive and more precise, because it takes into account the possible interactions between adaptives of different nature.
• the estimation of the corrective impact of the adaptives is directly defined in correction of the parameter which it is sought to control, which again contributes to a better accuracy of the limitation.
• the correction limitation permitted by the method according to the invention further contributes to controlling the richness and the polluting emissions of the engine.
• the estimation of the corrective impact of the adaptives carried out in the method according to the invention varies according to the current operating point of the engine. It is thus possible to define, for example, a fixed correction limit (for example +/- 3%) which will be followed at any point of operation of the motor.
• the process according to the invention thus makes it possible to limit, on specific phases of life of the engine where the confidence in the adaptive richness is not total, the risks of over-correction or under-correction of the richness and therefore the negative consequences on polluting emissions and driving pleasure.
• said at least one parameter is a fuel richness.
• the step of calculating, for each adaptive, an individual impact value of said adaptive on said at least one parameter consists of multiplying a current value of said adaptive by a predetermined transfer function between said at least one parameter and said adaptive, thereby providing the individual impact value.
• a transfer function represents the sensitivity of the adaptive to the parameter.
• the step of calculating an overall impact value of the set of adaptives on said at least one parameter consists in adding the individual impact values calculated for the set adaptive, thus providing the overall impact value.
• This step of calculating an overall impact value makes it possible to take into account the influence that the adaptives have on each other. For example, two adaptives of a different nature can, depending on the operating point of the engine, compensate each other in terms of richness correction if they have opposite signs.
• the step of comparing the calculated global impact value with at least one predefined global impact threshold value comprises a first phase consisting in comparing the calculated global impact value with a minimum global impact threshold value, and a second phase consisting in comparing the calculated global impact value with a maximum global impact threshold value, and the reduction factor to be applied is calculated if the calculated global impact value is less than the minimum global impact threshold value or greater than the maximum global impact threshold value.
• the step of calculating a reduction factor to be applied consists in dividing the value global impact threshold by the calculated global impact value, thus providing the reduction factor to be applied.
• the step of applying, to each of the adaptives, the calculated reduction factor consists in multiplying, for each of the adaptives, the current value of said adaptive by the calculated reduction factor. This makes it possible to limit the correction on the parameter which is carried out by the various adaptives and to follow, at any point of engine operation, the limits set by the predefined global impact threshold value(s).
• the predefined global impact threshold value(s) is (are) preferably configurable by a user or by a manufacturer of the vehicle. This makes it possible to calibrate this or these threshold value(s) as close as possible to what the regulatory texts require, in particular in terms of polluting emissions when the parameter is fuel richness.
• the predefined global impact threshold value(s) is (are) configurable according to distinct life phases of the engine, in order to take into account different needs of the system to limit the correction of the adaptives according to particular life phases of the engine.
• the steps of calculating individual impact values, of calculating an overall impact value, of comparing, of calculating a reduction factor to be applied and of applying said calculated reduction factor are repeated for each current operating point of the motor. This makes it possible to make the correction limitation of the parameter dependent on the current operating point of the motor. The precision in limiting the correction of the parameter is therefore greatly improved.
• FIG.1 is a flowchart representing a method for limiting a correction carried out by several adaptives on at least one parameter according to the present invention.
• the present invention relates to a method, implemented in engine control of a heat engine, for limiting a correction performed by several adaptive devices on at least one parameter.
• the parameter can be a richness of injected fuel but this is not limiting within the scope of the present invention.
• each adaptive is a fuel richness adaptive.
• the different adaptives are preferably applied directly to the sources of errors in fuel richness, that is to say to the modeling of the different elements of the heat engine. These adaptives are applied for example:
• a first adaptive can be an adaptive on the position of an intake camshaft phaser
• a second adaptive can be an adaptive on the position of a camshaft phaser with exhaust cams
• a third adaptive can be an adaptive on the modeling of the static gain of a fuel injector in the heat engine
• a fourth adaptive can be an adaptive on the modeling of the injector control dead time .
• one of the adaptives can also be an adaptive relating to an opening duration of at least one fuel injector in the heat engine.
• the method comprises a first step 10 during which the engine control calculates, for each of the adaptives, an individual impact value of the adaptive on the parameter for a current operating point of the engine.
• this calculation step 10 consists in multiplying, for each adaptive, a current value of the adaptive by a predetermined transfer function between the parameter and the adaptive. This multiplication then provides the individual impact value of the adaptive concerned, on the current operating point of the motor.
• This predetermined transfer function (and stored for example in motor control memory means) represents the sensitivity of the adaptive to the parameter.
• the transfer function can be determined beforehand by any known method, for example by mathematical calculations of derivatives of equations of the parameter of the system with respect to the adaptive considered, or by calculation of the local gradient of variation of the parameter for a variation adaptive.
• the motor control calculates an overall impact value of all the adaptives on the parameter for the current operating point of the motor.
• this calculation step 12 consists of adding the individual impact values calculated for all of the adaptives during the previous step 10. This addition then provides the overall impact value of the adaptives, on the point of normal engine operation.
• the engine control compares the overall impact value calculated during the previous step 12 with at least one predefined overall impact threshold value.
• the comparison step 14 includes for example a first phase consisting in comparing the calculated global impact value with a minimum global impact threshold value, and a second phase consisting in comparing the calculated global impact value with a threshold value maximum overall impact.
• the first phase can be performed before the second phase, or vice versa. Alternatively, the first and second phases are carried out simultaneously.
• the minimum and maximum global impact threshold values are typically values which can be parameterized by a user or a manufacturer of the vehicle. Preferably, these values can be parameterized according to distinct life phases of the motor. This makes it possible to take into account different needs of the system to limit the correction of the adaptives according to specific engine life phases.
• the parameter is the fuel richness
• the minimum and maximum global impact threshold values can be calibrated to zero.
• the user or the vehicle manufacturer may for example wish to authorize the adaptive richness to only enrich the fuel setpoint and strictly prohibit any reduction of this setpoint quantity (to avoid under-richness and therefore a risk of engine stalling for example).
• the minimum global impact threshold value will be set to zero over this phase of the engine's life.
• the motor control calculates, according to the result of the comparison carried out during the previous step 14, a reduction factor to be applied to the adaptive ones.
• the calculation of the reduction factor is performed by the motor control if the global impact value calculated during step 12 exceeds the predefined global impact threshold value.
• this calculation step 16 consists in dividing the predefined global impact threshold value by the global impact value calculated during step 12. This division then provides a reduction factor to be applied to the adaptives.
• the previous comparison step 14 comprises the two aforementioned phases
• the calculation of the reduction factor is performed by the engine control if the overall impact value calculated during step 12 is lower than the impact threshold value overall impact or greater than the maximum overall impact threshold value.
• the engine control then divides the overall impact threshold value which has not been respected, in other words the minimum or maximum overall impact threshold value as the case may be, by the overall impact value calculated during the step 12.
• the motor control applies to each of the adaptives the reduction factor calculated during the previous step 16.
• this application step 18 consists of multiplying, for each of the adaptives, the current value of the adaptive by the calculated reduction factor.
• a set of adaptives is obtained which have been reduced via the reduction factor.
• Steps 10, 12, 14, 16 and 18 described above are repeated for each current engine operating point.
• the method according to the invention allows a more exhaustive and more precise limitation of the correction carried out by the adaptives, and makes it possible to control the limitation of the parameter at any operating point of the engine and to take into account the possible interactions between adaptives, in particular when these adaptives are of a different nature.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Control Of Electric Motors In General (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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• 2021
  • 2021-05-27 FR FR2105501A patent/FR3123386B1/fr not_active Expired - Fee Related
• 2022
  • 2022-03-30 WO PCT/FR2022/050595 patent/WO2022248782A1/fr not_active Ceased
  • 2022-03-30 EP EP22717644.3A patent/EP4348024B1/de active Active

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