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
  • F02D41/2474—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
  • F02D41/2451—Methods of calibrating or learning characterised by what is learned or calibrated
• • 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
  • F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
  • F02D2041/1433—Introducing closed-loop corrections characterised by the control or regulation method using a model or simulation of the system
• • 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
  • F02D2200/0406—Intake manifold pressure

Definitions

• the present invention relates to a method of resetting at least two pressure sensors positioned in an air intake line of an internal combustion engine with prevention of a defect in one of the sensors, the detection of a defect in one of the sensors causing suspension of the implementation of the method.
• the invention lies in the technical field of the control system of an internal combustion engine which is preferably controlled ignition. It is common that, in an air intake line of an internal combustion engine, three pressure sensors are present, namely an atmospheric pressure sensor, a boost pressure sensor, this when the engine is turbocharged, the boost pressure sensor being downstream of a compressor of a turbocharger and an intake pressure sensor positioned in the air distributor. These three sensors are used to measure the existing pressure at certain specific points of the air intake line.
• the measurement of the same pressure by several sensors can give different values, due to their intrinsic and scalable accuracy. This occurs in particular with the engine stopped for which the pressure measured by each sensor is the atmospheric pressure, which will not necessarily be the case in operation of the engine.
• the resetting of the pressure sensors consists of compensating for this offset in order to equalize the values measured on the sensors when the pressure to be measured is the same. This operation is particularly necessary for the proper operation of driving a spark ignition engine.
• This delay makes it possible, on the one hand, to ensure that the intake line is at atmospheric pressure equilibrium, and on the other hand, to ensure that the sensors are in a state allowing them to perform a consistent measurement. During this delay, the differences in values measured between the reference sensor and each sensor to be readjusted are determined.
• the delay time is calibrated in a very short time. Its order of magnitude is 300 milliseconds.
• the registration is inhibited because it is considered that the registration is not reliable enough, the measured values having been distorted because one or more Pressure sensors were not in their optimal operating condition.
• Figure 1 illustrates a timing diagram as a function of time t of the method of resetting the pressure sensors according to the state of the art, the resetting process having been correctly carried out while Figure 2 illustrates a timing diagram according to the time t of the same method according to the state of the art, the start having been suspended by failure of the registration in the time determined before starting.
• FIGs 1 and 2 the sensors for atmospheric pressure, supercharging and air intake are respectively referenced Capatm, Capsural and Capadmi. These sensors are shown in these two figures at the top of the figure to the left unseated Capnrecal and then at the top of the figure to the right recalibrated Caprecal.
• An initial Div divergence between the Capatm, Capsural and Capadmi sensors to be rectified is greater in Figure 2 than in Figure 1.
• the timing diagram of Figures 1 and 2 shows a timer T for the registration of R sensors and a start D of the engine. In Figure 1, the sensors were reset in time and the start could take place.
• the reconfiguration flag is a Boolean variable of the engine control software representing the state of a diagnosis.
• the reconfiguration flag is used to identify a failure of a pressure sensor and the engine control functions use this flag to activate recovery strategies during a sensor failure.
• the transmission time of a configuration flag may be of the order of 2 seconds and is to be compared with that of the resetting delay and the need for rapid application of the registration.
• a reference sensor fault most commonly the Capatm atmospheric air pressure sensor
• the sensor failure is signaled only after the application of the registration.
• the diagnosis is not useful. But above all, the registration will be made from erroneous values, for example a value of 0.
• a pressure sensor has a measurement accuracy that depends on its temperature. Generally, the accuracy is optimal in the temperature range 0 ° C-90 ° C. It becomes much larger when the sensor is very cold ( ⁇ 0 ° C) or very hot (> 90 ° C).
• FIG. 3 illustrates the evolution of the error ranges as a function of the temperature respectively for two specific pressure sensors, namely a Capatm atmospheric pressure sensor and a Capsural supercharging sensor.
• the temperature is indicated on the abscissa with ordinate error multiplier values.
• a template having two curves delimits the range of errors for a succession of temperatures.
• the two dashed curves are associated with the Capsural Boost Sensor while the two full lines are associated with the Capatm Atmospheric Pressure Sensor.
• the curves for each sensor are different with a higher margin of error for the Capsural Boost sensor values than for the Capatm air pressure sensor.
• a Capatm atmospheric pressure sensor is accurate to +/- 15mb in the 0-85 ° C zone, while a Capsural boost pressure sensor is accurate to +/- 25mb in the same area.
• a maximum compensation compensation Crmax (T1) and Crmax (T) respectively for a temperature T1 or T can be defined between the points furthest apart from one another of one of the curves of the sensor. Capatm atmospheric pressure with one of the curves of the Capsural supercharging sensor, between the highest curve of the Capsural supercharging sensor and the lowest curve of the Capatm atmospheric sensor.
• Figure 3 shows that retaining the same adjustment compensation for all temperatures, it degrades the accuracy of the pressure measurement by a specific sensor. This can lead to unacceptable situations such as non-starting or loss of performance of the internal combustion engine, for example by the false determination of a target torque of the engine.
• the problem underlying the invention is to optimize a method of resetting sensors present in an air intake line of an engine with a failure detection of a sensor which is effective while not preventing the proper operation of the engine and in particular its startup.
• a method of resetting of at least two pressure sensors positioned in an air intake line of an internal combustion engine wherein said at least two pressure sensors are recalculated by a recalibration compensation calculated for at least a second sensor with respect to a first pressure sensor serving as a reference sensor between their respective pressure measurements at a so-called initial sensor temperature during a shutdown of the motor, this resetting compensation is then applied to said at least one second sensor for correction of its pressure measurements, characterized in that it is performed, prior to the application of the resetting compensation on said at least one second sensor , an internal diagnostic step based on the value of the resetting compensation of determining whether the resetting compensation exceeds a value in which case it is diagnosed that one of said at least two sensors has failed and that, in this case, the application of the resetting compensation is suspended.
• the technical effect is to obtain a method of resetting at least two pressure sensors that is freed from the time required for the development of diagnoses, this by performing a diagnosis directly in-house faster. This completely eliminates situations of non-starting or loss of performance caused by a registration process according to the state of the art requiring a significant diagnostic elaboration time.
• the registration is prohibited and is not carried out. This allows, on the one hand, not to reset the sensors to inconsistent values when the internal diagnosis indicates a failure and, on the other hand, to reset the sensors more quickly when the internal diagnosis indicates no failure.
• the solution proposed by the present invention is a software solution, simple to implement, because immediately integrable into a motor control. It is also very inexpensive since it does not require additional equipment. This solution is necessary because the resetting of the sensors is crucial for the proper functioning of the control of the air flow in the engine which can not function properly without this registration.
• the registration is done on at least three pressure sensors with a first reference sensor among said at least three sensors and, if the compensation of registration between the first sensor and the second and third sensors respectively exceed both. the maximum compensation value, it is diagnosed that the first sensor fails, while, if the compensation compensation of the first sensor exceeds the maximum compensation value with one of the second and third sensors when it does not exceed the maximum value with the other of the second or third sensors, it is diagnosed that the second or third sensor associated with a resetting compensation exceeding the maximum compensation value is defective.
• the maximum compensation value is specific to the pair or each pair formed by said at least two sensors, the maximum compensation value being greater than 20 or 30 millibars.
• a respective error mask as a function of the sensor temperature is developed for each sensor, the error mask of each sensor defining an error range for each temperature, the reset compensation being calculated from the difference of the respective pressure measurements of said at least two sensors at the initial temperature.
• the This compensation is suspended from 0 to 85 ° C. This makes it possible not to fall into the situation where the performance of the sensors is degraded because of a registration made hot or cold, that is to say below 0 ° C and above 85 ° C by setting up a system of inhibition of the registration.
• the application of the resetting compensation on said at least one second sensor it is expected for a predetermined time interval sufficient to perform a verification that the state of said at least two sensors allows them to perform a measurement of consistent pressure and if it is found that a sensor is not able to perform a consistent pressure measurement, the application of the resetting compensation is canceled, this time interval being about two seconds.
• the internal diagnosis to overcome the sensor diagnostic time it is set up a system for waiting for the reading of the verification made by an external diagnosis to the sensor, to confirm or cancel the registration. .
• This verification is based essentially on an external diagnosis that can be made by external control elements to the sensor.
• This external diagnosis is more comprehensive than the previous internal diagnosis but takes longer.
• the invention first of all provides for an internal diagnosis so as not to have any problem waiting for the internal diagnosis that may lead to a non-start, this internal diagnosis being verified by the longer external diagnosis of Implementation. It is thus planned to complete this internal diagnosis which may be false or incomplete by a more complete verification but requiring more time while still implementing the default registration process, this at least temporarily.
• the invention relates to a powertrain comprising an internal combustion engine with an air intake line to the engine, the line comprising a first and at least a second pressure sensor, characterized in that said at least one second pressure sensor is recalibrated with respect to the first pressure sensor according to a registration method as described above.
• the first and said at least one second pressure sensor are selected from an atmospheric pressure sensor, a supercharging sensor positioned downstream of a supercharged internal combustion engine turbocharger compressor and a pressure sensor. intake positioned in an intake manifold.
• the first sensor is the atmospheric pressure sensor.
• the engine is spark ignition.
• FIG. 1 is a diagrammatic representation of a chronogram of the progress of a resetting process according to the state of the art, the starting being successful, the pressure sensors being shown above this chronogram firstly according to FIG. a first graph in a non-recalibrated state and then according to a second graph in a recalibrated state,
• FIG. 2 is a schematic representation of a chronogram of the progress of a resetting process according to the state of the art, the pressure sensors being shown above this chronogram first of all according to a first graph in a state not recaled and then according to a second graph in a state recaled, the registration could not be done before the start and the start was suspended,
• FIG. 3 is a diagrammatic representation of two error templates for an atmospheric pressure sensor and a supercharging sensor respectively, the adjustment compensation not being adjusted as a function of temperature;
• FIG. 4 illustrates a logic diagram of the registration method according to the state of the art while FIG. 5 illustrates a logic diagram of the registration method according to the present invention.
• the present invention relates to a method of resetting at least two Capatm, Capsural, Capadmi pressure sensors positioned in an air intake line of a internal combustion engine.
• said at least two Capatm, Capsural, Capadmi pressure sensors are recalculated by a Cr (T1) or Cr (T) correction compensation calculated for at least a second Capsural sensor, Capadmi with respect to a first Capatm pressure sensor serving as a reference sensor between their respective pressure measurements at a so-called initial sensor temperature during engine shutdown.
• This compensation Cr (T1) correction or Cr (T) is then applied to the said at least a second sensor Capsural Capadmi for correction of its pressure measurements. According to the invention, it is performed, prior to the application of the resetting compensation on said at least one second sensor, an internal diagnostic step based on the value of the resetting compensation of determining whether the resetting compensation exceeds a maximum compensation value.
• the resetting compensation exceeds a maximum compensation value, it is diagnosed that one of said at least two sensors has failed and, in this case, the application of the resetting compensation is suspended.
• the maximum compensation value Crmax (T), Crmax (T1) may be specific to the pair or each pair formed by said at least two Capatm, Capsural, Capadmi sensors, the maximum compensation value Crmax (T ), Crmax (T1) being greater than 20 or 30 millibars.
• a respective error template depending on the temperature of the sensor Capatm, Capsural, Capadmi can be developed for each sensor, the error template of each Capatm sensor, Capsural, Capadmi defining a range of error for each temperature.
• the Cr (T1) or Cr (T) resetting compensation can then be calculated from the difference of the respective pressure measurements of the at least two Capatm, Capsural, Capadmi sensors at the initial temperature.
• the invention relates to a power train comprising an internal combustion engine with an air intake line to the engine, the line comprising a first and at least one second Capsural sensor, Capadmi pressure.
• said at least one second Capsural sensor, Capadmi pressure is recalibrated relative to the first sensor Capatm pressure in accordance with a method of registration as described above.
• Capadmi pressure can be selected from a Capatm atmospheric pressure sensor, a Capsural supercharger positioned downstream of a supercharged supercharged engine turbocharger compressor and a pressure sensor. Capadmi intake positioned in an intake manifold.
• Capatm atmospheric pressure sensor may only have a Capatm atmospheric pressure sensor and an air intake sensor Capadmi in the case of a motor not rbocom pressed.
• Other pressure sensors can also be taken into account.
• the first sensor within the meaning of the present invention can be the Capatm atmospheric pressure sensor, the latter being the most accurate and the internal combustion engine can be spark ignition.
• FIG. 4 shows a logic diagram of a method for resetting pressure sensors present in the air intake line of an internal combustion engine, this method being in accordance with the state of the art, while with reference to the other figures for references not indicated in this figure.
• This method of registration includes the step of starting or waking the computer referenced 1 in Figure 4. This is done as soon as the electrical contact is established for the motor vehicle. From this ignition, flows a timer T allowing the resetting of the pressure sensors as can be seen in Figures 1 and 2.
• the resetting of the pressure sensors by calculating the differences between the measured pressure values by the different sensors is referenced 2 in FIG. 4.
• a resetting compensation, previously referenced Cr (T) or Cr (T1) in FIG. 3, is thus calculated for each pressure sensor with respect to a reference sensor which is advantageously the Capatm atmospheric pressure sensor. It is then proceeded to the application of the registration during a step referenced 3a. This registration is done without internal diagnosis.
• the registration method according to the present invention retains the steps referenced 1 and 2 previously mentioned, relating respectively to the ignition of the computer, that is to say its awakening by its power, and the calculations of registration for the pressure sensors with respect to a reference sensor.
• the inventive contribution lies in the management of the authorizations of this registration.
• the resetting process according to the invention begins with the power of the computer in charge of the process.
• a first so-called time delay T is started as soon as the computer is powered up.
• the function of this delay time T is to ensure the equilibrium of the pressures in the air line and that the sensors are in the state to perform a consistent measurement. Turning on or starting the motor interrupts this delay.
• the step referenced 3 of the registration method according to the present invention relates to an internal diagnosis.
• the purpose of the internal diagnostic is to determine if one of the sensors detects a measurement of atmospheric pressure very far from the pressure measurement of the other or other sensors.
• an internal diagnostic step based on the value of the resetting compensation consisting in determining whether the resetting compensation Cr (T1 ) or Cr (T) exceeds a maximum compensation value Crmax (T), Crmax (T1), this internal diagnostic step being referenced 5 in FIG.
• the registration is done then on at least three Capatm, Capsural, Capadmi pressure sensors with a first reference Capatm sensor among said at least three Capatm, Capsural, Capadmi sensors. It is possible to determine which pressure sensor is defective among the three, the reference sensor can be as well as a recalibrated sensor. If the compensation compensations Cr (T1) or Cr (T) between the first sensor Capatm, that is to say the reference sensor and respectively the second and third sensors Capsural, Capadmi both exceed the value maximum compensation Crmax (T), Crmax (T1), it is diagnosed that the first Capatm sensor has failed.
• the reset compensation Cr (T1) or Cr (T) of the first Capatm sensor exceeds the maximum compensation value Crmax (T), Crmax (T1) with one of the second and third Capsural sensors, Capadmi while it does not exceed the maximum value with the other of the second or third sensors, it is diagnosed that the second or third Capsural sensor, Capadmi associated with a Cr (T1) or Cr (T) resetting compensation exceeding the maximum compensation value Crmax (T), Crmax (T1) has failed.
• Reference 6 in Figure 5 indicates the step of measuring the temperatures of the sensors. If the temperatures of the sensors go beyond a certain threshold, for example by leaving the temperature range between 0 and 85 ° C, then the initial adjustment compensation Cr (T1) or Cr (T) is suspended.
• each Capatm, Capsural, Capadmi sensor increases sharply, which leads to a degradation of the accuracy of each Capatm, Capsural, Capadmi sensor. If all the conditions are met, namely primarily a pressure measurement temperature in the interval and no outlier given by at least one sensor, at the end of the timer T, it is proceeded to the registration of the or pressure sensors with respect to one of the pressure sensors then being the reference sensor. This step is referenced 3 in FIG. 5. Only one of these two temperature or outlier conditions is sufficient to suspend the resetting.
• the verification step is carried out if a diagnostic variable for each sensor reveals a failure of the respective Capatm, Capsural, Capadmi sensor, this by a complete and external diagnosis. to the sensors. In this case, the registration performed in step 3 is canceled.
• This verification and cancellation or confirmation step is referenced 4 in FIG.
• This operation is done after registration since it can not be done before due to too long a period of time for the completion of the complete diagnosis on the sensors. Given the arrival time of the sensor's complete diagnostics variable, which is incompatible with the need to quickly reset the sensors, the registration takes place before any detection and confirmation of a fault but can be subsequently revised by being canceled.
• the complete diagnosis on the sensors does not arrive until after a certain period after registration. This period is of the order of 2 seconds. Nevertheless, if a fault of a sensor is detected by the complete diagnosis of the sensors, this fault is taken into account to cancel the resetting.
• the cancellation step or the confirmation of the resetting step is referenced 7.
• the sensors retain their original value while the registration is confirmed if no fault on the sensors is found.

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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)
• Measuring Fluid Pressure (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

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• 2016
  • 2016-02-04 FR FR1650882A patent/FR3047518B1/fr not_active Expired - Fee Related
• 2017
  • 2017-01-24 WO PCT/FR2017/050140 patent/WO2017134363A1/fr active Application Filing
  • 2017-01-24 CN CN201780007473.6A patent/CN108474314B/zh active Active
  • 2017-01-24 EP EP17706560.4A patent/EP3411580B1/de active Active

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