Method for maintaining the operation of an aircraft engine in the event of a pressure measurement failure

Abstract

Method for maintaining the operation of an aircraft engine in the event of a failure of a pressure measurement One aspect of the invention relates to a method for compensating for a failure of pressure measurement in an aircraft engine. Figure to be published with the abstract: Figure 4

Description

Title of the invention: Method for maintaining the operation of an aircraft engine in the event of failure of a pressure measurement TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of controlling the speed of an aircraft.

[0002] The present invention relates to a method for compensating for a failure of measurement of pressure in an aircraft engine. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] In an aircraft, the piloting instructions given by the pilot during the flight are transmitted to a computer, called FADEC for "Full Authority Digital Engine Control" in English, responsible for transcribing these instructions into commands to the various operating components of the aircraft. In this computer, these instructions are, in particular, compared with navigation instructions and parameters specific to each aircraft. These navigation instructions and parameters, such as maximum and / or minimum fuel consumption, are, for example, evaluated based on data from measurements in the engine.

[0004] In particular, the operating speed of the engine, i.e. its rotational speed, is limited by safety instructions relating to a maximum flow rate and a minimum flow rate of fuel that can be supplied to the engine. These maximum and minimum flow rates are calculated from measurements of physical properties, including the pressure downstream of the high-pressure compressor. The pressure at this location is conventionally obtained by calculating a static pressure, by the computer, in a thin tube, called a "capillary", one end of which is connected to the measurement location and the other to the computer.

[0005] The measurement of this pressure is however altered by the extreme environmental conditions of the device, for example in the event of the presence of water or frost in the tube, which distort the pressure calculated by the computer. Devices to protect the tubes from these extreme conditions, for example for defrosting, exist but remain insufficient and may not detect a measurement anomaly for this pressure, risking loss of control of the device.

[0006] There is therefore a need to improve the control of an aircraft in the event of an anomaly in the measurement of the pressure at the outlet of the high pressure compressor. Summary of the invention

[0007] The invention provides a solution to the problems mentioned above, by making it possible to detect a measurement failure not avoided or compensated for by the approaches of the art and which makes it possible to implement a mechanism for maintaining control of the device.

[0008] A first aspect of the invention relates to a method for compensating for a pressure measurement failure in an aircraft engine, the method comprising: • Detecting a pressure measurement failure by: • Detection of a pressure measurement anomaly by comparing the pressure measured at the outlet of a high-pressure compressor of the engine with a pressure model; and • Detection of an inconsistency in the operating speed of the aircraft engine with an instruction; • Compensate for measurement failure by: • Substitution of the pressure measurement by a pressure obtained by the pressure model; • Determination of a pumping protection limit and a shutdown protection limit from a time derivative of the operating regime, the pumping and shutdown protection limits replacing erroneous protection limits due to the pressure measurement anomaly; • Determination of a low power extinguishing limit from an idle speed of a high pressure body of the engine and / or a predefined limit of the pressure at the outlet of the high pressure compressor, the low power extinguishing limit being added to the pumping and extinguishing protection limits.

[0009] “Compensation” means a mechanism or logic, for example implemented in the form of instructions in a computer, which makes it possible to replace erroneous information, in this case a pressure measurement, by supplanting this information with one or more alternative data (the pressure modeled by the pressure model, the surge protection limit, the shutdown protection limit and the low power shutdown limit). These alternative data are then used to correct the piloting instructions for the aircraft components produced by the computer, in particular concerning the engine speed.

[0010] A "failure" in the pressure measurement is understood to mean an error in the calculation of the pressure by the computer due to a disturbance in the measurement device, thus producing an erroneous pressure value compared to the actual pressure at the measurement point, i.e. the pressure at the outlet of the high pressure (HP) compressor. In this case, the error in the calculation of the pressure by the computer may be the consequence of an obstruction in the capillary carrying the pressure from the outlet of the HP compressor to the computer, for example due to the presence of water or frost in this capillary.

[0011] A "measurement anomaly" means a contradiction between the measured pressure and the pressure estimated by the pressure model. In particular, there is an anomaly when a distance between the measurement and the model is significant.

[0012] An "inconsistency" in the operating speed is understood to mean a contradiction between the speed at which the engine operates and the instruction sent to it by the computer. This inconsistency is linked to the measurement anomaly mentioned above. That is to say, the behavior of the engine is not consistent with the instruction determined by the computer to respond to the pilot's instruction because this instruction is constructed on an erroneous measurement of the pressure downstream of the HP compressor. An instruction is therefore one or more commands issued by the computer to indicate to the engine components how they must operate or modify their operating mode to satisfy the instruction provided by the pilot.

[0013] The terms "pumping protection limit" and "extinguishing protection limit" are understood to mean two maximum and minimum limit values ​​for the fuel flow rate supplied to the engine to prevent pumping or extinguishing of the engine. These values ​​are used to replace the limits conventionally calculated by the computer since the latter are erroneous due to the pressure measurement anomaly.

[0014] "Low power shutdown limit" means a limit value to prevent the engine from shutting down when it is in a low power operating mode. This value ensures that the engine will not shut down even if the engine enters a low power operating mode and despite the failure of the pressure measurement.

[0015] Thanks to the invention, it is thus possible to detect a failure in the pressure measurement and then to trigger logic making it possible to maintain control of the aircraft.

[0016] The measurement failure is detected by determining two indicators: a significant difference between the measured pressure and the pressure model, this model making it possible to theoretically evaluate the temperature at the outlet of the HP compressor; and an inconsistency between the behavior of the engine and the instruction sent to it by the computer, which is determined as a function of the pressure measurement which is erroneous.

[0017] Compensation is then implemented to compensate for the failure of the pressure measurement. The compensation includes replacing the pressure measurement with the theoretical pressure calculated by the pressure model, which ensures that the computer constructs its engine control commands in accordance with the effective pressure of the HP compressor outlet, i.e. the actual pressure downstream of said compressor and not the abnormal pressure. The compensation also includes determining three stops in order to replace those conventionally calculated by the calculator and used to define the engine operating limits. In fact, the conventionally calculated limits are incorrect here since the pressure measurement does not correspond to the actual pressure in the engine. The compensation therefore replaces these values ​​with values ​​that ensure that the engine operates without major malfunctions, in particular without the risk of pumping and / or flameout.

[0018] In other words, compensation makes it possible to reconfigure the control of the engine via operating logic to ensure that the pilot retains control of the device even though the measurement of the pressure at the compressor outlet is faulty.

[0019] Thus, the pilot retains control of his aircraft even though there is a failure in the measurement of the pressure at the outlet of the HP compressor. Compensation can continue until the failure is resolved, for example by a capillary protection device or until the aircraft is stopped, once its flight is over.

[0020] Furthermore, the proposed method makes it possible not to be sensitive to a common mode failure. Indeed, a redundancy of the pressure measurement can be implemented and also be faulty due to the fact that the pressure is conveyed by the same capillary which is duplicated at the level of the redundant computers.

[0021] Finally, and in the case of measurement redundancy, the proposed method makes it possible to compensate for the failure and to maintain control of the aircraft even though a double sensor failure occurs, i.e. the respective pressure-sensitive sensors of the two redundant computers are both faulty due to an anomaly other than a fault in the capillary.

[0022] In addition to the characteristics which have just been mentioned, the method according to the first aspect of the invention may have one or more complementary characteristics among the following, considered individually or according to all technically possible combinations.

[0023] In one embodiment, the method according to the invention comprises: • Change the engine speed from the pressure obtained by the pressure model, the surge protection limit, the flameout protection limit and the low power flameout limit.

[0024] The engine operating speed is then corrected to comply with the instruction provided by the pilot, following new instructions or corrected instructions produced by the computer.

[0025] In one embodiment, the measurement anomaly is detected when a deviation of a measured value of the pressure with a theoretical value determined by the pressure model is greater than a predefined threshold.

[0026] In one embodiment, a measured value is obtained by measuring the pressure and a theoretical value is determined by the pressure model, and the substitution of the pressure measurement is implemented by replacing the value measured by the theoretical value.

[0027] In one embodiment, the setpoint is a fuel flow rate and the inconsistency is detected when: • the engine operating speed corresponds to deceleration or steady state while the fuel flow rate is equal to a maximum flow rate; or • the engine operating speed corresponds to acceleration while the fuel flow is equal to a minimum flow.

[0028] In other words, the engine operating speed inconsistency is detected when: • Although the computer issues a command to reach the maximum fuel flow, i.e. the engine speed is expected to accelerate, the engine speed remains unchanged or decelerates; or • Although the computer issues an instruction to reach the minimum fuel flow, i.e. the engine speed is expected to decelerate, the engine speed accelerates.

[0029] A second aspect of the invention relates to a device configured to implement the method according to the first aspect.

[0030] A third aspect of the invention relates to an aircraft comprising the device according to the second aspect of the invention.

[0031] A fourth aspect of the invention relates to a computer program product comprising instructions which, when the program is executed on a computer, cause the latter to implement the steps of the method according to the first aspect.

[0032] A fifth aspect of the invention relates to a computer-readable recording medium comprising instructions which, when executed by a computer, cause the computer to implement the steps of the method according to the first aspect.

[0033] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0034] The figures are presented for information purposes only and in no way limit the invention. • [Fig.l] is a block diagram illustrating the sequence of steps of a method for compensating for a pressure measurement failure in an aircraft engine, according to one embodiment. • [Fig.2] is a schematic representation of a device configured to implement a method of compensating for a failure to measure pressure in an aircraft engine, according to one embodiment. • [Fig.3] is a diagram illustrating the determination of a pressure estimate by a theoretical model according to one embodiment. • [Fig.4] is a block diagram illustrating the implementation according to one embodiment of the method for compensating for a pressure measurement failure in an aircraft engine. DETAILED DESCRIPTION

[0035] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0036] As described below, the invention proposes a method for compensating for a pressure measurement failure in an aircraft engine. This method makes it possible to substitute erroneous data processed by a computer with corrected or alternative data. The computer, also known as FADEC for "Full Authority Digital Engine Control" in English, is responsible for translating the pilot's piloting instructions into instructions for the components of the aircraft engine. The method comprises two main steps: the first is used to detect the pressure measurement failure and the second to compensate for the failure.

[0037] The sequence of steps of the method 100 is illustrated in [Fig.l].

[0038] Step 110 of detecting a pressure measurement failure is first implemented. This detection is based on the evaluation of two indicators representative of this failure, namely a comparison of the measured pressure with a theoretical model, and the identification of inconsistency between the actual operation of the engine and the instruction emitted by the computer.

[0039] Step 110 therefore comprises a step 111 of comparing the measured pressure with the pressure model.

[0040] The pressure is measured at the outlet of the high pressure (HP) compressor of the aircraft engine. The measurement is carried out by conventionally used techniques, for example via a capillary connecting the measurement location to the computer. The measured pressure is a static or quasi-static pressure.

[0041] The measurement is here subject to a malfunction, for example due to the presence of frost or water in the capillary or due to a malfunction of the element of the computer which is sensitive to pressure and connected to said capillary.

[0042] The pressure model is a predefined theoretical model, for example a model known per se or a model established by an operator. The model can therefore be any model which makes it possible to estimate a theoretical pressure which the computer should detect via its sensitive element. Advantageously, the pressure model can be a simplified or approximate model, with a margin of error less than or equal to 30%.

[0043] The measurement anomaly is therefore detected when a difference between the measured pressure and the pressure estimated by the model is greater than a predefined threshold. The predefined threshold is, for example, established by an operator according to the type and model of the aircraft, the characteristics of the computer and / or the engine components, and / or his professional knowledge.

[0044] In particular, a pressure value, called the "measured value", is obtained from the pressure measurement. Similarly, an estimated pressure value, called the "theoretical value", is obtained from the pressure model. Thus, the measurement anomaly is detected when a difference between the measured value and the theoretical value is greater than the predefined threshold. The difference between these two values ​​is, for example, equal to the absolute value of a difference between these two values. Other types of difference may be used, such as an absolute value of a difference of the squares of the values, a summation of the values, a summation of the square of the values, etc.

[0045] Step 110 also comprises a step 112 for detecting the inconsistency between the actual operation of the engine and the instruction sent by the computer. In particular, this step is used to detect an inconsistency between the operating speed of the engine and the instruction. The operating speed of the engine is here the rotation speed of the shafts N1 and / or N2.

[0046] An inconsistency may be detected when the engine speed decelerates or maintains a steady speed while the setpoint indicates that the engine speed should accelerate. Alternatively, an inconsistency may be detected when the engine speed accelerates while the setpoint indicates that the engine speed should decelerate.

[0047] In particular, the instruction issued by the computer relates to a fuel flow rate that must be supplied to the engine to satisfy the instruction given by the pilot. The fuel flow rate indicated by the instruction and determined by the computer is limited by a maximum threshold and by a minimum threshold, preventing the engine from entering surge or flameout. Consequently, when the fuel flow rate indicated in the instruction is equal to the maximum threshold or the minimum threshold, it is expected that the engine speed will accelerate or decelerate, respectively.

[0048] Therefore, the inconsistency between the engine operating speed and the setpoint is detected when: • The engine operating speed corresponds to deceleration or steady state while the engine fuel flow rate is equal to the maximum threshold; or • The engine operating speed corresponds to acceleration while the fuel flow is equal to the minimum threshold.

[0049] The maximum and minimum thresholds are determined by the calculator, in a manner known per se.

[0050] Therefore, when the measurement anomaly and the operating regime inconsistency are detected, then the measurement failure is detected.

[0051] Step 120 of compensating for the failure is then implemented. This step comprises three steps described below and relating to the substitution of the data necessary for the computer to determine the instructions by alternative or replacement data.

[0052] Step 120 thus comprises a step 121 of substituting the measured pressure with the pressure estimated by the pressure model. In other words, the measured value of the pressure is replaced, at the computer level, by the theoretical value. The computer can thus use a pressure value representative of the actual pressure at the outlet of the HP compressor to construct the setpoints, in particular to indicate the fuel flow rate to be supplied to the engine to satisfy the pilot's instruction.

[0053] Step 120 also includes a step 122 for determining a pumping protection limit and a shutdown protection limit. These limits are used to condition the computer so that the fuel flow rate that it calculates and indicates in its setpoint does not exceed the pumping protection limit and is not less than the shutdown protection limit. When there is no failure, these limits are calculated by the computer using techniques known per se. However, in the event of a failure, the conventional approaches fail and cause the inconsistency mentioned above. Consequently, the two determined limits are substituted for the conventionally determined limits, at the computer level. The computer therefore takes these determined limits into account and no longer the conventionally determined limits, to construct its setpoint and calculate the related fuel flow rate.

[0054] The pumping protection and extinction protection limits are determined from the operating regime, in particular from a time derivative of the operating regime. For example, the time derivative is that of the rotation speed of the shaft N1 or the shaft N2.

[0055] These limits are more restrictive than the limits conventionally calculated. They therefore ensure that the engine does not surge or flame out and that the pilot retains control of his aircraft.

[0056] Step 120 finally comprises a step 123 for determining a low power extinction limit. This limit indicates a value at which the fuel flow rate must not be lower than the risk of causing the engine to flame out while it is in low power mode. This limit is therefore added to the limits calculated in step 122 to constrain the computer in its determination of the setpoint and the calculation of the related fuel flow rate.

[0057] The low power extinction limit is determined from a body regime high pressure of the engine, i.e. the rotational speed of said body. The low power extinction limit can, alternatively or jointly, be calculated from a predefined limit of the pressure at the outlet of the high pressure compressor. This predefined limit is defined by the pressure model and / or by the operator depending on the type and model of the aircraft, the characteristics of the computer and / or the engine components, and / or his professional knowledge.

[0058] The method 100 may also comprise a step 130 of modifying the operating speed of the engine. During this step, the computer determines a new setpoint, or a corrected setpoint, and therefore a new fuel flow rate taking into account the replacement data determined in step 120.

[0059] The engine speed is therefore modified from the pressure obtained by the pressure model, the pumping protection limit, the shutdown protection limit and the low power shutdown limit.

[0060] The method 100 can be implemented by a device for compensating for a failure to measure pressure in an aircraft engine. Said device is therefore configured to implement said method 100. Such a device 10 comprises, for example and as shown diagrammatically in [Fig.2], a circuit comprising a processor 11, a volatile or non-volatile memory 12. The memory 12 is capable of storing instructions which, when implemented by the processor 11, lead the processor 11 to implement the steps of the method 100. The device 10 is, for example, a computer.

[0061] The circuit may alternatively comprise an electronic card whose steps of the method of the invention are described in the silicon, or even a programmable electronic chip such as an FPGA chip (for “Field-Programmable Gate Array” in English).

[0062] The device 10 also comprises an input interface 13 and an output interface 14. The input interface 13 is, for example, capable of receiving the measurement of the pressure to be compared to the model. More particularly, the input interface 13 is capable of receiving the measured value of the pressure. The input interface 12 is also capable of receiving the instruction emitted by the computer and the operating speed in which the engine is located. In particular, the input interface 12 is capable of receiving data indicating the operating speed of said engine.

[0063] The output interface 14 is capable of the theoretical value of the pressure obtained by the pressure model, the pumping protection limit, the extinction protection limit and the low power extinction limit determined via the implementation of the method 100.

[0064] The device 10 may, furthermore, be configured to implement calculations of the pressure model used by the method 100 and mentioned above. The device 10 therefore includes, in its memory 12, instructions which, when implemented by the processor 11, lead the latter to implement calculations of the pressure model. Alternatively, the calculations of the pressure model are implemented by an additional module dedicated to these calculations. This module is thus configured to provide the device 10 with the pressure estimated by the model, i.e. the theoretical value, in which case the input interface 13 of the device 10 is also capable of receiving this estimated pressure.

[0065] In some embodiments, the device 10 is attached to the computer. In other embodiments, the device 10 is included in the computer.

[0066] When two computers are used in redundancy, the device 10 may be a single device 10 for both computers or also be in redundancy, that is to say that there is a device 10 for or in each computer.

[0067] For the purpose of illustration, an example of implementation of the method 100, in particular step 110, is detailed below with reference to FIGS. 3 and 4.

[0068] The pressure measurement is carried out using a capillary connected on one side to the outlet of the HP compressor and on the other side to a pressure sensor in the aircraft's computer or FADEC.

[0069] The method 100 is implemented on a device 10 such as that presented above.

[0070] The device 10 obtains the measured pressure value from the calculator and compares it to the theoretical value estimated via the following pressure model. This model is an example of simplified modeling of pressure in a turbomachine and has the advantage of being simple and quick to implement. This model is suitable for double-spool dual-flow turbojets.

[0071] As illustrated in [Fig.3], obtaining the theoretical pressure value is determined by multiplying data from two different sub-models: • The first sub-model M1 is configured to determine a first pressure as a function of the speed of the low-pressure compressor of the engine; and • The second sub-model M2 is configured to determine a second pressure based on the high pressure compressor speed.

[0072] The first sub-model M1 takes as input a value of the speed of the low pressure compressor, i.e. its rotation speed, expressed as a percentage of the maximum speed of the high pressure compressor, and denoted PCNX2R. In the model, the speed of the low pressure compressor, denoted X„12, is used to determine X„12R such that 127? = ^12 ' °where -^12 is the estimated or measured temperature at the outlet of the low pressure compressor. The value of PCN12R is expressed as a function of X„12 / ?, for example in the form of a ratio with the maximum speed of the high pressure compressor denoted Xn25MAX.

[0073] The second model M2 takes as input a value of the speed of the high pressure compressor, i.e. its rotation speed, expressed as a percentage of the maximum speed of this high pressure compressor, and denoted PCN25R. In the model, the speed of the low pressure compressor, denoted X„25 is used to determine Xn25R such that Xn25R = ^;25, °where T25 is the estimated or measured temperature at the outlet of the low pressure compressor. The value of PCN25R is expressed as a function of Xn25R, for example in the form of a ratio with Xtl25MAX.

[0074] The sub-models M1 and M2 are known per se and are, for example, obtained by analyses and measurements carried out during engine tests according to approaches known to those skilled in the art.

[0075] The first pressure calculated by the first model M1 is multiplied by an estimate, or a measurement, of the total pressure PT2 upstream of the rotor of the low pressure compressor. This multiplication produces an intermediate pressure value. This intermediate value is then multiplied by the second calculated pressure. At the end of the second multiplication, the theoretical value PS3th of the pressure estimated by the pressure model is produced.

[0076] The theoretical value PS3th is then compared, in step 111 and as illustrated in FIG. 4, to the measured value, which is noted PS3. It is considered that the accuracy of this model is equal to 30% and is noted e30. The measurement anomaly is thus determined when: • PS3 £ PS3d 1 - g); or when • PS3> PS3th(l + e)-

[0077] The error e is the approximation error of the pressure model. For the model presented, the error here is 30%.

[0078] In the proposed example, at step 112 and as illustrated in [Fig.4], the inconsistency is detected when: • WF32c.,w / = WF32„U1X and that dNi < q; or when dï “ WF32^ = WF32„î / n and that £5 » n-dt '

[0079] The fuel flow rate indicated in the computer instruction is denoted WF32cmd. The maximum fuel flow rate authorized for the engine, also determined by the computer, is denoted WF3%nax. The minimum fuel flow rate authorized for the engine, also determined by the computer, is denoted WF32min. The time derivative of the rotational speed of the shaft N2 is denoted , where r is time. dt

[0080] It is noted that the inconsistency could be indifferently detected by using the time derivative of the speed of the NI shaft instead of that of the N2 shaft.

[0081] It is possible to perform the inconsistency detection redundantly, by example a second time at a time following the first inconsistency detection to confirm this detection.

[0082] The measurement failure is then detected in two cases: • When the inconsistency is due to the fact that the N2 shaft speed indicates deceleration or stagnation while the control fuel flow is equal to the maximum fuel flow and the measured pressure value is less than the theoretical pressure value less the error; or • When the inconsistency is due to the fact that the N2 shaft speed indicates acceleration while the control fuel flow is equal to the minimum fuel flow and the measured pressure value is greater than the theoretical pressure value plus the error.

[0083] In addition to the conditions of these two cases, the failure can be detected provided that the engine is not stalled, that is to say that the engine is not pumping, and provided that said engine is switched on.

[0084] Step 120 is then implemented by the device and, in step 121, the theoretical pressure value is used by the computer to determine the setpoints instead of the measured value.

[0085] In step 122, the pumping protection limit and the flameout protection limit are calculated and replace the maximum and minimum fuel flow rates conventionally calculated by the computer such that: = ( 1 + e'i.ClP,,,.,., PS^nsjb ; "WF32 ml "=(the).ClP m „„ PS3^T25 / b■

[0086] The value of the coefficient b is determined by the operator and is, for example, b = 288.15. C / Pma* is a high stop which limits the fuel flow to protect the HP compressor from pumping due to overconsumption of pumping margin linked to thermal throttling created by the fuel level. The value of C / Pmax can be determined by any method known in the state of the art.

[0087] In addition, control loops are implemented and serve to limit the acceleration rate and the deceleration rate of the HP body. The acceleration rate is thus limited by a maximum value noted dN2 and a minimum value noted ^3. These dl max dt min control loops, known in themselves, allow the application of more restrictive protection but nevertheless allow acceleration and deceleration to be ensured in the event of a pressure measurement failure.

[0088] Accordingly, the engine is doubly protected from surge or flameout by overriding the maximum and minimum fuel flow rates and by limiting the acceleration and deceleration rates.

[0089] The device can then transmit this data to the computer which can construct, according to step 130, then send to the devices of the device a new instruction based on this data to respond to the piloting instruction required by the pilot.

Claims

Claims

1. Method (100) for compensating for a pressure measurement failure in an aircraft engine, the method comprising: - Detecting (110) a pressure measurement failure by: • Detecting a pressure measurement anomaly by comparing (111) the pressure measured at the outlet of a high-pressure compressor of the engine with a pressure model; and • Detecting (112) an inconsistency in the operating speed of the aircraft engine with a setpoint; - Compensating (120) for the measurement failure by: • Substituting (121) the pressure measurement with a pressure obtained by the pressure model; • Determination (122) of a pumping protection limit and a shutdown protection limit from a time derivative of the operating regime, the pumping and shutdown protection limits replacing erroneous protection limits due to the pressure measurement anomaly;• Determination (123) of a low power extinction limit from an idle speed of a high pressure body of the engine and / or a predefined limit of the pressure at the outlet of the high pressure compressor, the low power extinction limit being added to the pumping and extinction protection limits.;

2. Method according to the preceding claim, comprising: - Modifying (130) the engine speed from the pressure obtained by the pressure model, the surge protection limit, the shutdown protection limit and the low power shutdown limit.

3. Method according to one of the preceding claims, wherein the measurement anomaly is detected when a deviation of a measured value of pressure with a theoretical value determined by the pressure model is greater than a predefined threshold.

4. Method according to one of the preceding claims, a measured value being obtained by measuring the pressure and a theoretical value being determined by the pressure model, wherein the substitution of the pressure measurement is implemented by replacing the measured value with the theoretical value.

5. Method according to one of the preceding claims, in which the setpoint is a fuel flow rate and in which the inconsistency is detected when: - The operating speed of the engine corresponds to a deceleration or to a stationary speed while the fuel flow rate is equal to a maximum threshold; or - The operating speed of the engine corresponds to an acceleration while the fuel flow rate is equal to a minimum threshold.

6. Device (10) for compensating for a failure to measure a pressure in an aircraft engine configured to implement the method (100) according to one of the preceding claims.

7.

8. Aircraft comprising the device (10) according to the preceding claim. Computer program product comprising instructions which, when the program is executed on a computer, cause the latter to implement the steps of the method (100) according to one of claims 1 to "

9. J. A computer-readable recording medium comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the method (100) according to one of claims 1 to 5.

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