EP3411580A1

EP3411580A1 - Method for resetting two pressure sensors in an air-intake line of an engine with sensor fault prevention

Info

Publication number: EP3411580A1
Application number: EP17706560.4A
Authority: EP
Inventors: Philippe Quie; Julien LEMIERE; Jean Louis CHARRIER
Original assignee: PSA Automobiles SA
Current assignee: PSA Automobiles SA
Priority date: 2016-02-04
Filing date: 2017-01-24
Publication date: 2018-12-12
Anticipated expiration: 2037-01-24
Also published as: EP3411580B1; WO2017134363A1; CN108474314B; CN108474314A; FR3047518A1; FR3047518B1

Abstract

The invention concerns a method for resetting at least two pressure sensors (Capatm, Capsural, Capadmi) positioned in an air-intake line of an internal combustion engine, the resetting compensation being calculated for at least one second sensor (Capsural, Capadmi) with respect to a first pressure sensor (Capatm) acting as a reference sensor between the respective pressure measurements of same at a so-called initial temperature of the sensors when the engine is stopped. Before applying the resetting compensation to said at least one second sensor (Capsural, Capadmi), an internal diagnostic step is carried out based on the value of the resetting compensation, consisting or determining whether the resetting compensation exceeds a maximum compensation value, in which case it is diagnosed that one of said at least two sensors is faulty. In this case, application of the resetting compensation is suspended.

Description

METHOD FOR REPLACING TWO PRESSURE SENSORS IN AN AIR INTAKE LINE OF AN ENGINE WITH PREVENTION OF A SENSOR FAULT

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.

It is therefore necessary to reset these pressure sensors before use, this adjustment being done during a stop of the engine before starting the vehicle. 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.

Currently, it is known a method of resetting the pressure sensors of the air intake line. The steps of this registration process are as follows. At the engine stop, the three sensors measure the same pressure: the atmospheric pressure. We therefore take advantage of this phase of life to make the registration. For this registration, a reference sensor is chosen by calibration. It is in relation to the measurement of this sensor that the other sensors will be recaled. This reference sensor must be the most accurate sensor. This is frequently the case for an atmospheric pressure sensor which is most often preferred as a reference sensor. At the initialization of an on-board computer in the motor vehicle and carrying out control of the powertrain and its auxiliary elements, a timer is started. 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.

At the end of this delay, these differences are then added to the values of the sensors to be reset to compensate for the offset. In order to ensure that the resetting is carried out in most starting cases, even fast starts for which the motor has only been briefly stopped, the delay time is calibrated in a very short time. Its order of magnitude is 300 milliseconds.

If the actuation of the engine takes place before the end of the delay, then 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.

[001 1] 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.

In Figures 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. From the establishment of an electrical contact triggering the awakening I of an on-board computer in the motor vehicle, 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. In Figure 2, it was estimated that the sensors could not be recalibrated in time, which does not necessarily correspond to reality. It is then emitted by a Pancap control element a failure notice which indicates a failure Def which prevents the start, the non-starting being referenced nD in Figure 2 which illustrates this case. In Figure 2, poor management of a detection of a sensor fault is illustrated, this mismanagement can lead to a situation where the engine can not start. When the diagnosis of the sensors of the air intake line is made, it takes a certain time before the confirmation and recovery of a failure Def, this rise may occur after the actual registration R sensors. Def fault recovery can be done by issuing a reconfiguration flag, also known as the Anglo-Saxon flag. The reconfiguration flag is a Boolean variable of the engine control software representing the state of a diagnosis. When a diagnosis is made, if a fault is detected and confirmed, then the reconfiguration flag associated with this diagnosis is 1. If there is no confirmed fault, then it is 0.

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. Thus, in the event of 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.

In addition, in the closest state of the art, there is no consideration of the temperature of the pressure sensors for calculating the registration. This can bring to a significant degradation of the accuracy of the sensor. The driving performance of the vehicle is then degraded and even there may be an impossibility of starting.

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.

For each sensor, 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.

For example, 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. The same is true for an air intake pressure sensor positioned in an air distributor as for a Capsural boost pressure sensor, without the gauge of this intake pressure sensor being shown at the same time. FIG. 2. 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. For example, taking as a reference sensor the Capatm atmospheric pressure sensor, when the maximum resetting compensation Crmax (T1), previously taken for the temperature T1, is applied in the central zone of Sensor accuracy for the Capsural Supercharging Sensor, for example at temperature T, can result in the accuracy of this Capsural Supercharging Sensor being exceeded outside the intrinsically accurate terminals of its gauge.

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.

Document US Pat. No. 7,668,687 describes a system that makes it possible to carry out corrections on pressure sensors by comparing the pressures of the sensors between them, with the engine stopped. This corresponds to the registration of the sensors relative to each other. By cons, this document gives no indication as to a prevention of a defect in a sensor, the detection of such a defect resulting in the suspension of the implementation of the registration process. The same goes for a possible compensation of a sensor registration or pressure sensors taking into account the temperature variation near the sensors.

Therefore, 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.

To achieve this objective, there is provided according to the invention 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.

If the internal diagnosis finds a failure, then 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.

Advantageously, 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.

Thus, it can easily be determined which sensor of the three sensors present is faulty, the probability that two sensors are simultaneously failing being very small.

Advantageously, 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. Advantageously, 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.

Advantageously, it is performed, prior to the resetting compensation, a temperature measurement step at said at least two sensors and if the temperature is not within a predetermined temperature range, 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.

This makes it possible to work with recalibrated sensors in an area of optimum accuracy of the sensors. Outside this precision zone, there would be a possibility of degradation of the accuracy of the sensors due to too much compensation of maximum registration. By taking into account the temperature of the sensors, the situations of no starting or loss of performance caused by the method according to the state of the closest technique are completely eliminated.

Advantageously, after 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. Thus, after 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. For this reason, 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.

Indeed, if this verification indicates a failure of one or sensors, the registration process is canceled because it is considered to distort the accuracy of the sensors. The registration process will then have been applied only for a reduced period of time which has little or no effect on the optimal operation of the engine.

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.

Advantageously, 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.

[0046] Advantageously, the first sensor is the atmospheric pressure sensor.

[0047] Advantageously, the engine is spark ignition. Other features, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the accompanying drawings given by way of non-limiting examples and in which:

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.

It is to be borne in mind that the figures are given by way of examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the 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 reference numerals.

Figures 1 to 3 have already been detailed in the introductory part of this application.

Referring to the figures, and in particular to FIG. 5, 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.

In this method, 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.

If 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.

Advantageously, 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. Advantageously, 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.

After applying the reset compensation Cr (T1) or Cr (T) on said at least one second Capsural sensor, Capadmi, it can be expected a predetermined time interval sufficient to perform a verification that the state of said At least two Capatm, Capsural and Capadmi sensors enable them to perform a coherent pressure measurement.

If it is found that a Capatm, Capsural, Capadmi sensor is not in a position to carry out a coherent pressure measurement, the application of the Cr (T1) or Cr (T) resetting compensation may be canceled. The predetermined time interval may be about two seconds. 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. In this powertrain, 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.

As generally present in an air intake line to a turbocharged internal combustion engine with an intake air distributor, the first capatm and said at least one second Capsural sensor, 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.

For example, it 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. Then, if a failure is detected, in the next step referenced 4, it is proceeded to the suspension of the engine start or if no failure is detected, it is proceeded to start the engine. No updating of the resetting compensation with respect to the temperature of the sensors that can vary is provided in this method of registration according to the state of the art.

Referring to the figures and in particular to Figure 5, 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. As for the state of the art shown in FIG. 4, 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.

During this delay, it is proceeded to the step referenced 2 in FIG. 5 with calculation of the compensation compensations Cr (T1) or Cr (T) between the pressure sensors, this step being also part of the method of registration according to the state of the art. 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.

To do this, we use the offset compensation values Cr (T1) or Cr (T) previously calculated and are compared to a threshold. If these values are beyond a threshold then this means that one of the sensors has failed. This step is done with a motor stopped.

Thus, prior to applying the resetting compensation on a pressure sensor, 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.

In this case, it is diagnosed that the sensor has failed and, in this case, the application of the resetting compensation is suspended. This makes it possible not to reset the sensors to incoherent values.

In the preferred embodiment of the present invention, there may be three pressure sensors in the air intake line to the engine. 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. Conversely, if 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.

It can indeed be observed with regard to FIG. 3 that below and above this interval, the precision interval of 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.

However, a variable of a complete diagnosis for each Capatm, Capsural, Capadmi sensor is expected for a period of time following the registration. referenced 3 in Figure 5. Despite the internal diagnostic step referenced 5, it is important to take into account the sensor diagnosis. Indeed, the internal diagnosis is effective to avoid inconsistent readings on erroneous values, but it is much less complete than this complete and external diagnosis for each sensor. The complete diagnosis time D for each sensor starts on powering up the computer and continues longer than the timer T by exceeding for example two seconds.

As a result, failures may not have been diagnosed during the internal diagnostic step 5 while these failures can be signaled by a complete sensor diagnosis. Thus, during a period after registration, of approximately two seconds, 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.

In FIG. 5, the cancellation step or the confirmation of the resetting step is referenced 7. After the cancellation step, the sensors retain their original value while the registration is confirmed if no fault on the sensors is found.

The invention is not limited to the described and illustrated embodiments which have been given only as examples.

Claims

Method for adjusting at least two pressure sensors (Capatm, Capsural, Capadmi) positioned in an air intake line of an internal combustion engine, in which said at least two sensors (Capatm, Capsural, Capadmi) pressure are readjusted by a readjustment compensation (Cr(T1) or Cr(T)) calculated for at least a second sensor (Capsural, Capadmi) in relation to a first pressure sensor (Capatm) serving as a reference sensor between their respective pressure measurements at a so-called initial temperature of the sensors when the engine stops, this resetting compensation (Cr(T1) or Cr(T)) then being applied to said at least one second sensor (Capsural, Capadmi) to correction of its pressure measurements, characterized in that it is carried out, prior to the application of the adjustment compensation (Cr(T1) or Cr(T)) on said at least one second sensor (Capsural, Capadmi), an internal diagnostic step based on the value of the reset compensation (Cr(T1) or Cr(T)) consisting of determining whether the reset compensation (Cr(T1) or Cr(T)) exceeds a maximum compensation value (Crmax(T), Crmax(T1)), in which case it is diagnosed that one of said at least two sensors (Capatm, Capsural, Capadmi) is faulty and in that, in this case, the application of the compensation of resetting (Cr(T1) or Cr(T)) is suspended.

Method according to claim 1, in which the registration is carried out on at least three pressure sensors (Capatm, Capsural, Capadmi) with a first reference sensor (Capatm) among said at least three sensors (Capatm, Capsural, Capadmi) and, if the adjustment compensations between the first sensor (Capatm) and respectively the second and third sensors (Capsural, Capadmi) both exceed the maximum compensation value (Crmax(T), Crmax(T1)), it is diagnosed that the first sensor (Capatm) is faulty, while, if the adjustment compensation (Cr(T1) or Cr(T)) of the first sensor (Capatm) exceeds the maximum compensation value (Crmax(T), Crmax(T1)) with one of the second and third sensors (Capsural, Capadmi) while it does not exceed the maximum value with the other of the second or third sensors (Capsural, Capadmi), it is diagnosed that the second or third sensor ( Capsural, Capadmi) associated with a reset compensation (Cr(T1) or Cr(T)) exceeding the maximum compensation value (Crmax(T), Crmax(T1)) is faulty. Method according to any one of claims 1 or 2, in which the maximum compensation value (Crmax(T), Crmax(T1)) is specific to a pair or to each pair formed by said at least two sensors (Capatm, Capsural , Capadmi), the maximum compensation value (Crmax(T), Crmax(T1)) being greater than 20 or 30 millibars.

Method according to any one of the preceding claims, in which a respective error template as a function of the temperature of the sensor (Capatm, Capsural, Capadmi) is developed for each sensor (Capatm, Capsural, Capadmi), the error template of each sensor (Capatm, Capsural, Capadmi) defining an error range for each temperature, the adjustment compensation (Cr(T1) or Cr(T)) being calculated from the difference in the respective pressure measurements of said at least two sensors (Capatm, Capsural, Capadmi) at the initial temperature.

Method according to any one of the preceding claims, in which a step of measuring the temperature is carried out, prior to the adjustment compensation (Cr), at said at least two sensors (Capatm, Capsural, Capadmi) and if the temperature is not within a predetermined temperature interval, the reset compensation (Cr(T1) or Cr(T)) is suspended, this interval being from 0 to 85°C.

Registration method according to any one of the preceding claims, in which, after application of the registration compensation (Cr(T1) or Cr(T)) on said at least one second sensor (Capsural, Capadmi), it is waited for a predetermined time interval sufficient to verify that the state of said at least two sensors (Capatm, Capsural, Capadmi) allows them to carry out a coherent pressure measurement and that if it is found that a sensor (Capatm, Capsural , Capadmi) is not able to carry out a coherent pressure measurement, the application of the adjustment compensation (Cr(T1) or Cr(T)) is canceled, this time interval being approximately two seconds.

Powertrain comprising an internal combustion engine with an air intake line to the engine, the line comprising a first (Capatm) and at least one second pressure sensor (Capsural, Capadmi), characterized in that said at least one second pressure sensor (Capsural, Capadmi) is realigned relative to the first pressure sensor (Capatm) in accordance with a registration method according to any one of the preceding claims.

8. Powertrain according to claim 7, in which the first (Capatm) and said at least one second pressure sensor (Capsural, Capadmi) are selected from an atmospheric pressure sensor (Capatm), a boost sensor (Capsural) positioned downstream of a supercharged internal combustion engine turbocharger compressor and an intake pressure sensor (Capadmi) positioned in an intake air distributor.

9. Powertrain according to any one of claims 7 or 8, wherein the first sensor is the atmospheric pressure sensor (Capatm).

10. Powertrain according to any one of claims 7 to 9, wherein the engine is spark ignition.