EP3411581B1 - Method for calibrating a pressure sensor in an air intake line of an engine with compensation according to temperature - Google Patents

Description

The invention relates to a method for readjusting at least one pressure sensor positioned in an air intake line of an internal combustion engine with a compensation for readjustment adjusted as a function of temperature.

The invention lies in the technical field of the command and control system of an internal combustion engine which is preferably with spark ignition.

Frequently, 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 located 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 pressure existing at certain specific points on the air intake line.

A pressure sensor has a measurement accuracy which depends on its temperature. Generally, the accuracy is optimal in the temperature range 0 ° C-90 ° C with a reduced error range. The error range becomes much larger when the sensor is very cold, for temperatures below 0 ° C, or very hot for temperatures above 90 ° C.

Thus, a sensor can be readjusted with the engine stopped at an initial temperature, advantageously between 0 and 90 ° C. by a compensation of readjustment being the difference between a measurement of said at least one pressure sensor and the atmospheric pressure then corresponding to a pressure of reference effectively prevailing in the intake line at this initial temperature.

It is also possible to readjust a pressure sensor to another so-called reference sensor and even to readjust several pressure sensors relative to the same reference sensor. Indeed, the measurement of the same pressure by several sensors can give different values, which is due to their intrinsic and evolving precision.

Adjusting pressure sensors consists in compensating for this offset, in order to equalize the measurement values of the sensors on the same measured pressure. This operation is in particular necessary for the correct operation of the piloting of a spark-ignition engine.

There is currently a solution for readjusting the pressure sensors of the air intake line. When starting, with the engine stopped, the intake line is at atmospheric pressure and the three sensors must indicate the same value which is that of atmospheric pressure as reference pressure.

C_r(T1) étant la compensation de recalage à la température initiale et moteur arrêté, P_capteur(T1) étant la mesure de pression par ledit au moins un capteur de pression et P_ref(T1) la pression de référence qui est la pression atmosphérique, ceci à la température T1.In practice, given the inaccuracies of the sensors, there is a difference between the values measured by the respective sensors. The sensors are then readjusted to the value of the sensor chosen as a reference, by applying a compensation compensation being the difference between a measurement of said at least one pressure sensor and the atmospheric pressure then corresponding to a reference pressure actually prevailing in the intake line at this initial temperature according to the following equation: $${\mathrm{VS}}_{\mathrm{r}}\left(\mathrm{T}1\right)={\mathrm{P}}_{\mathrm{sensor}}\left(\mathrm{T}1\right)-{\mathrm{P}}_{\mathrm{ref}}\left(\mathrm{T}1\right)$$

C _r (T1) being the compensation of readjustment at the initial temperature and engine stopped, P _sensor (T1) being the pressure measurement by said at least one pressure sensor and P _ref (T1) the reference pressure which is the pressure atmospheric, this at temperature T1.

The registration compensation is then kept and applied during the entire engine running time for the pressure sensor concerned.

The adjustment applied by compensation nevertheless raises the following problems. The first problem is that the temperature of the pressure sensors is not taken into account for compensation, which can lead to a significant deterioration in the accuracy of the sensor concerned. Indeed, the accuracy of the sensors is a function of the temperature while the compensation applied is constant.

Thus, when the temperature of the sensors varies during operation, the compensation adjustment applied is no longer adapted to the actual conditions. This phenomenon is all the more marked the greater the temperature difference between the registration and the operation. This is for example the case, without being limiting, for a resetting carried out initially at very low temperature during a subsequent heating due to the operation of the engine.

The figure 1 illustrates the evolution of the error range of a pressure sensor as a function of the temperature indicated on the abscissa with ordinates of error multiplier values. For a sensor precise to +/- 15millibars between 0 and 85 ° C, it has an accuracy of +/- 30millibars at -40 ° C and +/- 36millibars at 140 ° C.

For a temperature T, the error of a pressure sensor can be expressed in the form e _ref . mult (T), with e _ref being a sensor reference error and mult (T) an error multiplier. The error multiplier is dependent on the temperature and its variation as a function of the temperature is given by the sensor manufacturer according to a defined curve.

With several pressure sensors present in the air intake line to the engine, if each sensor has the same precision profile, the absolute error values are not identical.

The figure 2 illustrates the evolution of the error ranges as a function of the temperature respectively for two specific pressure sensors, namely an atmospheric pressure sensor and a boost sensor. The temperature is indicated on the abscissa with ordinates of error multiplier values.

For each sensor, a template comprising two curves delimits the range of errors for a succession of temperatures. The two dotted curves are associated with the Capsural boost sensor while the two solid lines are associated with the Capatm atmospheric pressure sensor. The curves for each sensor are different with a higher margin of error for the values of the Capsural boost sensor than for the Capatm atmospheric pressure sensor.

For example, a Cap atm atmospheric pressure sensor is accurate to +/- 15mb in the 0-85 ° C area, while a Capsural boost pressure sensor is accurate to +/- 25mb in the same area. The same applies for an intake pressure sensor as for a Capsural boost pressure sensor, without the size of this intake pressure sensor being shown on the figure 2 .

A maximum readjustment compensation C _rmax (T1) and C _rmax (T) respectively for a temperature T1 or T can be defined between the points furthest from each other one of the curves of the Capatm atmospheric pressure sensor with one of the curves of the Capsural boost sensor, between the highest curve of the Capsural boost sensor and the lowest curve of the Capatm atmospheric sensor.

For example, taking as reference sensor the atmospheric pressure sensor Capatm, when the maximum registration compensation C _rmax (T1), previously taken for the temperature T1, is applied in the median zone of optimal accuracy of the sensors for the sensor of Capsural boost, for example at temperature T, this can cause the accuracy of this Capsural boost sensor to go outside the intrinsic precision limits of its size. This is shown by the vertical dotted line coming out from the bottom of the Capsural boost pressure sensor template.

The figure 2 shows that by keeping the same readjustment compensation for all temperatures, the accuracy of the pressure measurement is degraded by a specific sensor, which can lead to unacceptable situations for example of non-starting or loss of engine performance with internal combustion, for example by the false determination of a torque of the target engine.

The document US-B-7 668 687 describes a system which makes it possible to carry out corrections on pressure sensors by comparing the pressures of the sensors with one another, with the engine stopped. This corresponds to the readjustment of the sensors with respect to each other. On the other hand, this document gives no indication as to a possible compensation for a readjustment of a sensor or of pressure sensors taking account of the temperature variation near the sensors.

Other systems which allow correction of pressure sensors using a corrective term are known from the documents EP1193385A2 , DE10261382A1 and WO2010004152A1 .

It is necessary to have a function which makes it possible to provide at least the same pressure precision in the air intake line while reducing the intrinsic precision of the sensor, and therefore its cost.

It is also necessary, in the case of several sensors present in the air intake line, to readjust the sensors with respect to each other so that their measurements are consistent with each other. This also applies when a single sensor is present so that its measurements correspond to the pressure then actually existing, this under all operating conditions.

Consequently, the problem underlying the invention is for an air intake line in an internal combustion engine comprising at least one sensor pressure, to readjust the pressure sensor measurements by adding a readjustment compensation which is updated according to the operating conditions of the engine implying a temperature change in the vicinity of the sensor (s).

C_r(T1) étant la compensation de recalage initiale à la température initiale et moteur arrêté, P_cap(T1) étant la mesure de pression par ledit au moins un capteur de pression, P_ref(T1) la pression de référence qui est la pression atmosphérique et T1 la température initiale, la mesure dudit au moins un capteur de pression étant recalée par la compensation de recalage initiale ainsi calculée, caractérisé en ce qu'en fonctionnement du moteur, à une température donnée, la compensation de recalage est ajustée à partir de cette compensation de recalage initiale en fonction de la température dudit au moins un capteur de pression par un facteur correctif multiplicatif.To achieve this objective, there is provided according to the invention a method for readjusting at least one pressure sensor positioned in an air intake line of an internal combustion engine, for which said at least one pressure is readjusted with the engine stopped at an initial temperature by an initial readjustment compensation being the difference between a measurement of said at least one pressure sensor and the atmospheric pressure then corresponding to a reference pressure actually prevailing in the intake line to this initial temperature according to the following equation: $${\mathrm{VS}}_{\mathrm{r}}\left(\mathrm{T}1\right)={\mathrm{P}}_{\mathrm{cape}}\left(\mathrm{T}1\right)-{\mathrm{P}}_{\mathrm{ref}}\left(\mathrm{T}1\right)$$

C _r (T1) being the initial readjustment compensation at the initial temperature and engine stopped, P _cap (T1) being the pressure measurement by said at least one pressure sensor, P _ref (T1) the reference pressure which is the atmospheric pressure and T1 the initial temperature, the measurement of said at least one pressure sensor being adjusted by the initial adjustment compensation thus calculated, characterized in that in operation of the engine, at a given temperature, the adjustment compensation is adjusted to starting from this initial registration compensation as a function of the temperature of said at least one pressure sensor by a multiplicative corrective factor.

The technical effect is to obtain measurements from at least one pressure sensor present in the air intake line of an internal combustion engine which are always corrected as a function of the temperature.

The error characteristics of the sensor (s) being known, a multiplicative factor is calculated depending on the temperature of the sensor which corrects the compensation for adjustment determined before start-up and called initial, in order to adapt the adjustment whatever the temperature of the sensor. , given that during operation, the temperature in the vicinity of the sensors varies, therefore the accuracy of the sensors as well as the compensation compensation previously calculated for an initial temperature.

The main advantage is an improvement in the accuracy of pressure measurements. Taking into account the effects of temperature on the sensors reduces the measurement error of the sensors. The engine air intake line sensors are readjusted whatever the temperature. The implementation is purely software, does not require the addition of new components in the air intake line and therefore does not entail any additional cost.

Advantageously, an initial registration compensation is carried out for at least one second pressure sensor with respect to a first pressure sensor between their respective pressure measurements at an initial temperature with, in operation of the engine and at a given temperature, adjustment of adjustment compensation from this initial compensation compensation as a function of the temperature, said at least one second sensor and the first sensor being positioned in the intake line, a respective error template as a function of the temperature of the sensor being developed for each sensor, each error template defining a specific error range at successive temperatures, the compensation compensation being carried out between pressure measurements of the first and said at least one second sensor at successive temperatures.

C_r(T) étant la compensation de recalage entre les deux capteurs à un instant donné pour une température donnée T, C_r(T1) la compensation de recalage initiale à la température initiale T1 à moteur arrêté et k(T) le facteur correctif multiplicatif pour la température donnée T, ce facteur étant calculé en fonction des compensations de recalage maximales entre les plages d'erreur respectives du premier capteur et dudit au moins un deuxième capteur pour la température donnée et pour la température initiale selon l'équation suivante : $$\mathrm{k}\left(\mathrm{T}\right)={\mathrm{C}}_{\mathrm{rmax}}\left(\mathrm{T}\right)/{\mathrm{C}}_{\mathrm{rmax}}\left(\mathrm{T}1\right)$$

k(T) étant le facteur correctif multiplicatif pour la température donnée T, C_rmax(T) et C_rmax(T1) les compensations de recalage maximales entre les plages d'erreur respectives du premier capteur et dudit au moins un deuxième capteur respectivement pour la température donnée et pour la température initiale T1 avec moteur arrêté.Advantageously, the compensation compensation for a given temperature T is obtained according to the following equation: $${\mathrm{VS}}_{\mathrm{r}}\left(\mathrm{T}\right)=\mathrm{k}\left(\mathrm{T}\right).{\mathrm{VS}}_{\mathrm{r}}\left(\mathrm{T}1\right)$$

C _r (T) being the adjustment compensation between the two sensors at a given time for a given temperature T, C _r (T1) the initial adjustment compensation at the initial temperature T1 with the engine stopped and k (T) the corrective factor multiplicative for the given temperature T, this factor being calculated as a function of the maximum readjustment compensations between the respective error ranges of the first sensor and of said at least one second sensor for the given temperature and for the initial temperature according to the following equation: $$\mathrm{k}\left(\mathrm{T}\right)={\mathrm{VS}}_{\mathrm{rmax}}\left(\mathrm{T}\right)/{\mathrm{VS}}_{\mathrm{rmax}}\left(\mathrm{T}1\right)$$

k (T) being the multiplicative corrective factor for the given temperature T, C _rmax (T) and C _rmax (T1) the maximum compensation compensations between the respective error ranges of the first sensor and said at least one second sensor respectively for the given temperature and for the initial temperature T1 with the engine stopped.

Advantageously, each template is made up of two curves delimiting a margin of error, the margin of error remaining constant in a temperature range from 0 to 85 ° C. and increasing for temperatures outside this range the more these temperatures move away from 0 ° C or 85 ° C.

Advantageously, on the basis of the respective error templates, a table is produced giving the compensation for maximum registration as a function of the temperature.

The invention also relates to a powertrain comprising an internal combustion engine with an air intake line to the engine, the line comprising at least one pressure sensor, characterized in that said at least one pressure sensor is readjusted in accordance to a registration process as above.

The invention also 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 sensor pressure is reset in operation of the engine relative to the first pressure sensor in accordance with a registration process as described above.

Advantageously, the first sensor and said at least one second sensor are selected from an atmospheric pressure sensor, a boost sensor positioned downstream of a turbocharger compressor of a supercharged internal combustion engine and an intake pressure sensor positioned in an intake air distributor.

Advantageously, the first sensor is the atmospheric pressure sensor.

Advantageously, the engine is with spark ignition.

• la figure 1 est une représentation schématique d'une courbe donnant le multiplicateur d'erreur d'un capteur de pression en fonction de la température, une gamme médiane de température donnant un multiplicateur d'erreur constant alors que hors de cette gamme, le multiplicateur d'erreur diverge, le capteur de pression étant conforme à l'état de la technique mais pouvant être corrigé conformément à un procédé de recalage selon la présente invention,
• la figure 2 est une représentation schématique de deux gabarits d'erreur pour respectivement un capteur de pression atmosphérique et un capteur de suralimentation, la compensation de recalage étant ajustée en fonction de la température conformément à un procédé de recalage selon la présente invention,
• la figure 3 est une représentation schématique d'un chronogramme du procédé de recalage selon la présente invention,
• la figure 4 est une représentation schématique d'un logigramme montrant les étapes du procédé de recalage selon la présente invention.

Other characteristics, aims and advantages of the present invention will appear on reading the detailed description which follows and with regard to the appended drawings given by way of nonlimiting examples and in which:

• the figure 1 is a schematic representation of a curve giving the error multiplier of a pressure sensor as a function of temperature, a median temperature range giving a constant error multiplier while outside this range, the error multiplier diverges, the pressure sensor being in accordance with the state of the art but can be corrected in accordance with a registration process according to the present invention,
• the figure 2 is a schematic representation of two error templates for an atmospheric pressure sensor and a supercharging sensor respectively, the adjustment compensation being adjusted as a function of the temperature in accordance with a registration method according to the present invention,
• the figure 3 is a schematic representation of a timing diagram of the registration process according to the present invention,
• the figure 4 is a schematic representation of a flowchart showing the steps of the registration process according to the present invention.

It should be borne in mind that the figures are given by way of examples and are not limitative of the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention.

In what follows, reference is made to all the figures taken in combination. When reference is made to one or more specific figures, these figures are to be taken in combination with the other figures for the recognition of the designated numerical references.

The present invention relates to a method of readjusting at least one pressure sensor positioned in an air intake line of an internal combustion engine. The present invention can be applied to a powertrain comprising an internal combustion engine with an air intake line to the engine, the line comprising at least one pressure sensor. The engine can preferably be with spark ignition.

In the case of a single pressure sensor, the pressure sensor can be readjusted in accordance with the registration process which will be described.

In the case of several pressure sensors present in an air intake line to the engine, one of the pressure sensors serves as a reference sensor and the other sensor or sensors are readjusted in operation of the engine relative to the pressure sensor of reference in accordance with a registration process which will be described.

As nonlimiting examples, the reference pressure sensor and the remaining pressure sensor (s) can be selected from an atmospheric pressure sensor, a supercharging sensor positioned downstream of a supercharged internal combustion engine turbocharger compressor and a intake pressure sensor positioned in an intake air distributor. The reference pressure sensor can be the atmospheric pressure sensor, this sensor being the most precise.

The figure 3 shows a timing diagram of the implementation of the registration process according to the present invention. The offset compensation is calculated on awakening of an Rcal computer on board the motor vehicle for which it is desired reset at least one pressure sensor positioned in an air intake line of an internal combustion engine fitted to the vehicle.

The Rcal computer can be awakened as soon as the driver has switched on the ignition, but without having started the engine. A period of keeping the engine stopped MA begins with the awakening of the computer Rcal and ends with the starting of the engine D.

During this period of maintaining the engine stopped MA, an initial registration compensation referenced below C _r (T1) is compared with the figure 2 serving as a basis for future adjustment of a pressure sensor present in the engine air intake line. The initial registration compensation C _r (T1) is the difference between a measurement of the pressure sensor and the atmospheric pressure. The atmospheric pressure then corresponds to a reference pressure actually prevailing in the intake line at this initial temperature T1, the engine being stopped.

This initial engine temperature is very likely to be around ambient temperature, unless the vehicle has just stopped and is ready to restart, in which case the engine is still warm. The initial temperature will probably be in the optimal measurement area of the pressure sensor, for example between 0 ° C and 50 ° C unless the outside temperature is very cold.

To the figure 2 , for clarity of the figure and also to explain an extreme case, the temperature T1 has been indicated as being less than 0 ° C to be well spaced from the temperature T in engine operation which is greater than 0 ° C. This is by no means limiting and it should be borne in mind that the initial temperature T1 is in the most frequent cases greater than 0 ° C., cbnc within the optimum operating range of most pressure sensors.

C_r(T1) étant la compensation de recalage initiale à la température initiale T1 et moteur arrêté, P_cap(T1) étant la mesure de pression par ledit au moins un capteur de pression et P_ref(T1) la pression de référence qui est la pression atmosphérique, ces mesures étant prises à la température initiale T1.This compensation is done according to the following equation: $${\mathrm{VS}}_{\mathrm{r}}\left(\mathrm{T}1\right)={\mathrm{P}}_{\mathrm{cape}}\left(\mathrm{T}1\right)-{\mathrm{P}}_{\mathrm{ref}}\left(\mathrm{T}1\right)$$

C _r (T1) being the initial readjustment compensation at the initial temperature T1 and engine stopped, P _cap (T1) being the pressure measurement by said at least one pressure sensor and P _ref (T1) the reference pressure which is atmospheric pressure, these measurements being taken at the initial temperature T1.

The measurement of the pressure sensor and the following measurements of the sensor are readjusted by the compensation compensation C _r (T1) thus calculated which is readjusted successively as a function of the prevailing temperatures in the engine.

The registration process thus comprises a step of adjusting the initial registration compensation C _r (T1) during engine operation as a function of the temperature of the pressure sensor by a multiplicative corrective factor.

This can be done for a pressure sensor relative to atmospheric pressure, the compensation for resetting the pressure sensor to an initial temperature with the engine stopped between its measurement which was to be atmospheric pressure and atmospheric pressure being updated by depending on temperatures.

However, this is preferably carried out between two or more pressure sensors, including a reference sensor, the pressure sensors being positioned in the air intake line of the engine.

In the latter case, an initial registration compensation is carried out for at least a second pressure sensor with respect to a first pressure sensor between their respective pressure measurements at an initial temperature. Then, in operation of the engine and at a given temperature T, an adjustment of registration compensation C _r (T) is made from this initial compensation compensation C _r (T1) as a function of the prevailing temperature T at this measurement.

A respective error template or equivalent model depending on the temperature of the sensor is developed for each sensor, each error template defining a specific error range at successive temperatures.

The readjustment compensations C _r (T1) or C _r (T) are carried out between pressure measurements of the first and of the second sensor or of other temperatures for successive temperatures. This is done with the MT engine running. In fact, the initial registration compensation C _r (T1) was firstly calculated on awakening of the RCal computer, engine stopped at temperature T1. During the operation of the engine, in particular the rolling vehicle, the temperature varies and therefore the precision of the sensor (s) and the compensation for registration C _r (T1) or C _r (T) also vary.

C_r(T) étant la compensation de recalage entre les deux capteurs à un instant donné pour une température donnée T, C_r(T1) la compensation de recalage initiale à la température initiale T1 à moteur arrêté et k(T) le facteur correctif multiplicatif pour la température donnée T.In the preferred embodiment of the invention, the compensation for registration or C _r (T) at a given temperature T is obtained according to the following equation: $${\mathrm{VS}}_{\mathrm{r}}\left(\mathrm{T}\right)=\mathrm{k}\left(\mathrm{T}\right).{\mathrm{VS}}_{\mathrm{r}}\left(\mathrm{T}1\right)$$

C _r (T) being the compensation compensation between the two sensors at a given time for a given temperature T, C _r (T1) the compensation of initial adjustment at the temperature initial T1 with the engine stopped and k (T) the multiplicative corrective factor for the given temperature T.

k(T) étant le facteur correctif multiplicatif pour la température donnée T, C_rmax(T) et C_rmax(T1) les compensations de recalage maximales entre les plages d'erreur respectives du premier capteur et dudit au moins un deuxième capteur respectivement pour la température donnée T et pour la température initiale T1 avec moteur arrêté.The factor k (T) is calculated as a function of the maximum adjustment compensation C _rmax (T1) or C _rmax (T) between the respective error ranges of the first sensor and of said at least one second sensor for the given temperature (T ) and for the initial temperature (T1) according to the following equation: $$\mathrm{k}\left(\mathrm{T}\right)={\mathrm{VS}}_{\mathrm{rmax}}\left(\mathrm{T}\right)/{\mathrm{VS}}_{\mathrm{rmax}}\left(\mathrm{T}1\right)$$

k (T) being the multiplicative corrective factor for the given temperature T, C _rmax (T) and C _rmax (T1) the maximum compensation compensations between the respective error ranges of the first sensor and said at least one second sensor respectively for the given temperature T and for the initial temperature T1 with the engine stopped.

As the error templates of the sensors are known, it is possible to produce a table of maximum registration compensations, this table being indexed in temperature. As shown in the figure 2 . The table can then be refined by tests, for a more precise determination than that based on the characteristic of a theoretical error.

Each template can consist of two curves delimiting a margin of error, the margin of error remaining constant in a temperature range from 0 to 85 ° C and increasing for temperatures outside this range the more these temperatures move away from 0 ° C or 85 ° C.

The figure 4 illustrates the various stages of the registration process according to the present invention. MA references the engine stopped, Pcap the measurement of a pressure sensor and Pref the reference pressure measurement, in particular atmospheric pressure, at an initial temperature T1 which is the reference temperature. These parameters are introduced into a first calculation module 1.

The first calculation module 1 sends the registration compensation C _r which corresponds to the registration compensation at temperature T1 to a correction module 5 calculating a corrected registration compensation Crcorrig.

At the same time, the first calculation module 1 sends the temperature value T1 to a second calculation module for the maximum registration compensation C _rmax (T1) for the initial temperature T1, this second module being referenced 2. A third module calculates the maximum registration compensation C _rmax (T) for a temperature T according to the temperature measurement sent to its input, this third module being referenced 3. This is done when the engine is running, therefore with a MT running engine. The calculations of the third module 3 are made continuously on a succession of temperatures at the level of the sensors.

The initial maximum registration compensation C _rmax (T1) for the initial temperature T1 can be calculated by the second module 2 via a table indexed in temperature. This table is calculated from the sensor error templates.

At each calculation step of the third module, the maximum registration compensation C _rmax (T) can be calculated for the temperature then in force T thanks to a table indexed in temperature. This table is the same as that used to calculate the initial maximum registration compensation C _rmax (T1) at the initial temperature T1.

The second module 2 and the third module 3 send the respective calculated maximum registration compensations C _rmax (T1) and C _rmax (T) to a fourth module 4 for calculating the coefficient k. The fourth calculation module 4 transmits to the correction module 5 forming the fifth module calculating the corrected registration compensation Crcorrig.

Claims (10)

1. A method for calibrating at least one pressure sensor positioned in an air intake line of an internal combustion engine, for which said at least one pressure sensor is calibrated with the engine stopped at an initial temperature (T1) by initial calibration compensation (C_r(T1)) being the difference between a measurement (Pcap) of said at least one pressure sensor and the atmospheric pressure then corresponding to a reference pressure (Pref) prevailing effectively in the intake line at this initial temperature (T1) according to the following equation: $${\mathrm{C}}_{\mathrm{r}}\left(\mathrm{T}1\right)={\mathrm{P}}_{\mathrm{cap}}\left(\mathrm{T}1\right)-{\mathrm{P}}_{\mathrm{ref}}\left(\mathrm{T}1\right)$$

   

   C_r(T1) being the initial calibration compensation at the initial temperature (T1) and with the engine stopped, P_cap(T1) being the pressure measurement by said at least one pressure sensor, P_ref(T) the reference pressure which is the atmospheric pressure and T1 the initial temperature,

   the measurement of said at least one pressure sensor being calibrated by the initial calibration compensation (C_r(T1)) thus calculated,

   characterized in that in operation of the engine, at a given temperature (T), the calibration compensation (C_r(T)) is adjusted from this initial calibration compensation (C_r(T1)) as a function of the temperature (T) of said at least one pressure sensor by a multiplying correction factor.
2. The calibration method according to Claim 1, in which an initial calibration compensation is carried out for at least one second pressure sensor with respect to a first pressure sensor between their respective pressure measurements at an initial temperature with, in operation of the engine and at a given temperature (T), adjustment of a calibration compensation (C_r(T)) from this initial calibration compensation (C_r(T)) as a function of the given temperature (T), said at least one second sensor and the first sensor being positioned in the intake line, a respective error template as a function of the temperature of the sensor being developed for each sensor, each error template defining a specific error range at successive temperatures, the calibration compensations (C_r(T1) or C_r(T)) being carried out between pressure measurements of the first and of said at least one second sensor at successive temperatures.
3. The calibration method according to Claim 2, in which the calibration compensation C_r(T) at a given temperature (T) is obtained according to the following equation: $${\mathrm{C}}_{\mathrm{r}}\left(\mathrm{T}\right)=\mathrm{k}\left(\mathrm{T}\right).{\mathrm{C}}_{\mathrm{r}}\left(\mathrm{T}1\right)$$

   

   C_r(T) being the calibration compensation between the two sensors at a given moment for a given temperature T, C_r(T1) the initial calibration compensation at an initial temperature T1 with the engine stopped, and k(T) the multiplying correction factor for the given temperature T, this factor being calculated as a function of the maximum calibration compensations (C_rmax(T1) or C_rmax(T)) between the respective ranges of error of the first sensor and of said at least one second sensor for the given temperature (T) and for the initial temperature (T1) according to the following equation: $$\mathrm{k}\left(\mathrm{T}\right)={\mathrm{C}}_{\mathrm{rmax}}\left(\mathrm{T}\right)/{\mathrm{C}}_{\mathrm{rmax}}\left(\mathrm{T}1\right)$$

   

   k(T) being the multiplying correction factor for the given temperature T, C_rmax(T) and C_rmax(T1) the maximum calibration compensations between the respective ranges of error of the first sensor and of said at least one second sensor respectively for the given temperature (T) and for the initial temperature (T1) with the engine stopped.
4. The calibration method according to Claim 2 or 3, in which each template is composed of two curves delimiting a margin of error, the margin of error remaining constant in a temperature range of 0 to 85 °C and increasing for temperatures outside this range, the more these temperatures move away from 0 °C or from 85 °C.
5. The calibration method according to any one of Claims 2 to 4, in which, from respective error templates, a table is developed giving the maximum calibration compensation (C_rmax(T1) or C_rmax(T)) as a function of the temperature.
6. A powertrain including an internal combustion engine with an air intake line to the engine, the line including at least one pressure sensor, characterized in that said at least one pressure sensor is calibrated in accordance with a calibration method according to Claim 1.
7. A powertrain including an internal combustion engine with an air intake line to the engine, the line including a first and at least one second pressure sensor, characterized in that said at least one second pressure sensor is calibrated in operation of the engine with respect to the first pressure sensor in accordance with a calibration method according to any one of Claims 2 to 5.
8. The powertrain according to any one of Claims 6 or 7, in which the first sensor and said at least one second sensor are selected from an atmospheric pressure sensor, a supercharging sensor positioned downstream of a turbocharger compressor of a supercharged internal combustion engine, and an intake pressure sensor positioned in an intake air distributor.
9. The powertrain according to any one of Claims 6 to 8, in which the first sensor is the atmospheric pressure sensor.
10. The powertrain according to any one of Claims 6 to 9, in which the engine is a spark ignition engine.

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