Self-testing method for angle of attack detector, method for checking airflow velocity provided by a group of related pitot tube detectors, angle of attack detector

Abstract

The present invention relates to a self-testing method (100) for an angle of attack detector, comprising the following steps: (110) controlling the angular excitation of a rotating element around its equilibrium position according to known excitation characteristics; (120) obtaining an angular measurement value relative to the rotation of the rotating element; (130) determining a parasitic torque applied to the rotating element according to the angular measurement value and the excitation characteristics; (160) comparing at least one component of the parasitic torque with at least one predetermined threshold; (170) indicating that an operational fault of the detector has been detected when the component exceeds the predetermined threshold.

Description

Technical Field

[0001] The invention relates to a self-testing method of an angle of attack detector.

[0002] The invention also relates to a method for checking the airflow velocity provided by a set of related pitot tube probes, and an angle of attack probe.

[0003] The angle of attack detector of the present invention can measure the angle of attack of an aircraft. Background Art

[0004] In the prior art, there are many techniques for locally measuring the angle of attack of an aircraft. This local angle measurement is usually different from the global angle measurement, which allows the corresponding avionics system to extrapolate the angle of attack of the entire aircraft upstream without restriction.

[0005] Of the known art, the most common are rotating probes. There are basically two main types of rotating probes: "vane" probes, ie probes with paddles, and probes with differential pressure equalization between two areas.

[0006] Despite appearances, all types of rotating probes share the same basic principle: the probe's axis of symmetry is aligned with the relative wind axis.

[0007] For a vane probe, due to the aerodynamic balance on both sides of the rotating element with the blade, it is possible to return towards a balance position, in which the profile of the blade is symmetrical. Since the thrust center of the blade is arranged behind the axis of rotation, the blade finds its balance on the axis relative to the wind. The angle sensor converts the information into a signal that can be used by the system and the pilot.

[0008] For the differential pressure equalization probe, the part exposed to the airflow has an aerodynamic profile which is symmetrical in the equilibrium position with respect to the relative wind axis, but also with respect to the axis of rotation. The differential pressure equalization probe is therefore a cone, not a paddle as in the previous case.

[0009] Due to this symmetry, the cone is not affected by any rotational aerodynamic forces, whatever the angle of rotation relative to the relative wind axis. There are no aerodynamic return forces. The two slots are arranged on either side of the cone generatrix. A differential sensor measures the pressure deviation between the two openings, or more simply, the inner partition finds its equilibrium position when the pressure values ​​on both sides of the inner partition are equal.

[0010] For example, the inner partition has a rotation element, the rotation angle of which can be determined by a sensor provided for this purpose. This rotation angle then characterizes the pressure and is used to locally determine the angle of attack of the aircraft.

[0011] Given the importance of the angle of attack measured by angle of attack probes, these probes are usually associated with test rigs that allow their failure to be detected.

[0012] These faults may be caused by parasitic torques applied to rotating elements of the probe, for example after it has been de-iced.

[0013] Thus, for example, document FR2626375 is known, which describes an angle of attack probe in which the damping function is performed electromagnetically so as to present a minimum of dry friction and / or parasitic torques. The same device can be positioned in a predetermined position for testing purposes. This function allows the probe to be tested statically while the aircraft is on the ground.

[0014] However, this solution does not allow checking the integrity of the values ​​provided by the in-flight probes.

[0015] Other solutions used in the art are basically based on the merging of data from other sensors to determine the plausibility of the angle of attack data.

[0016] In particular reference is made to the use of velocity measurements along the axis of the aircraft in relation to the vertical acceleration relative to the aircraft. If the configuration of the wings and flaps and the approximate mass of the aircraft are known, calculations can be used to return to the range of possible angles of attack using inertia, aircraft aerodynamic configuration and engine thrust parameters.

[0017] However, a disadvantage of this solution is that it is not sufficient to ensure the required degree of integrity.

[0018] First, the scheme is based on the complete synchronization of several other systems. Therefore, if just one of these systems fails or is simply inaccurate, a false alarm will occur. This could cast doubt on the angle measurement, leading to incorrect decisions for the rest of the flight.

[0019] Secondly, the accumulated uncertainty of other parameters leads to uncertainty in the estimated angle of attack value. Now, in some flight phases, the angle deviation between normal flight and stall is very small. Also, false alarms may lead to the erroneous removal of the probe's measurements without a reliable backup.

[0020] Thus, in a configuration comprising, for example, only two sets of angle of attack measurements, it may happen that only one set of measurements is erroneous, regardless of the cause of the error, even if it is a software cause. Summary of the invention

[0021] The present invention proposes a self-testing function of an angle of attack detector, which can be realized in flight without using data from other similar detectors.

[0022] To this end, the present invention relates to a self-testing method for an angle of attack detector, which is capable of measuring the angle of attack of an airflow within a measuring area and includes a rotating element, which is rotatable around a rotation axis that is basically perpendicular to the direction of the airflow under the influence of the airflow, and the rotating element defines an equilibrium position, in which the rotation of the rotating element around the rotation axis is stabilized by the airflow.

[0023] The method comprises the following steps:

[0024] - controlling the angular excitation of the rotating element about its equilibrium position according to known excitation characteristics;

[0025] - obtaining an angular measurement relative to the rotation of the rotating element;

[0026] - determining a parasitic torque applied to the rotating element based on the angle measurement and the excitation characteristics;

[0027] - comparing at least one component of said parasitic torque with at least one predetermined threshold value;

[0028] - When said component exceeds said predetermined threshold, an indication is given of a detection of an operational fault of said detector.

[0029] According to further advantageous aspects of the invention, the self-testing method of the invention comprises one or more characteristics considered individually or in all technically possible combinations:

[0030] - determining the parasitic torque using a transfer function describing the rotation of the rotating element in the presence of the parasitic torque, the parasitic torque being defined by an inertial component such as an abnormal moment of inertia, a damping component, a proportional component such as an abnormal aerodynamic torque, and a friction or unbalance component of the mass;

[0031] - determining said inertia component, said damping component and said friction and imbalance components by identifying the parasitic torque portion corresponding to each respective component by subtracting a predetermined portion of the maximum normal torque in its likelihood domain;

[0032] - obtaining at least one value of the modulus of the velocity of the air flow, said at least one value being called coincident velocity, coming from a measuring device substantially separate from said probe;

[0033] The measuring device is another angle of attack probe or a velocity measurement group preferably comprising one or more pitot tube probes and / or one or more lidars;

[0034] - determining the proportional component and the pressure velocity of the gas flow relative to each other using the first mechanized operation or the second mechanized operation;

[0035] According to the first mechanized operation, substituting the uniform speed into the transfer function, and determining the proportional component using other components of the parasitic torque;

[0036] According to the second mechanization operation, the proportional component is determined by a predetermined value, and a pressure velocity value called an extrapolation velocity is determined using a set of components of the parasitic torque;

[0037] In one aspect, comparing a consistent speed according to the first mechanized operation with an extrapolated speed according to the second mechanized operation,

[0038] On the other hand, the proportional component according to the first mechanized operation is compared with the proportional component according to the second mechanized operation,

[0039] If the comparison is within a predetermined likelihood domain, establishing an appropriate operating criterion;

[0040] - the excitation characteristic defines a sinusoidal excitation of the rotating element, preferably with a pseudo-random frequency;

[0041] - Acquire data related to aerodynamic noise;

[0042] - adjusting the excitation characteristics according to the acquired data related to aerodynamic noise.

[0043] The present invention also relates to a method for checking the air flow velocity provided by a group of Pitot tube detectors, wherein the group of Pitot tube detectors includes multiple Pitot tube detectors and multiple static pressure detectors, and the group of Pitot tube detectors can provide air flow pressure velocity values, which are called first velocity values ​​and can be determined using the values ​​from the Pitot tube detectors and the static pressure detectors.

[0044] The inspection method is implemented using a group of angle of attack detectors, which include a plurality of angle of attack detectors, each of which is capable of measuring the angle of attack of the airflow, and includes a rotating element and a processing module, wherein the rotating element rotates around a rotation axis under the influence of the airflow, and the processing module is capable of executing the self-test method as described above.

[0045] When no operation failure of the angle of attack detector is detected after the processing module of each angle of attack detector executes the self-test method, the inspection method is executed.

[0046] The inspection method comprises the following steps:

[0047] - obtaining pressure velocity values ​​determined by a processing module of a set of angle of attack sensors, each of said values ​​being referred to as a second velocity value;

[0048] - comparing the second velocity value with the first velocity value and determining among these values ​​a velocity value representing the pressure velocity of the air flow;

[0049] -The speed value to be transmitted and its accuracy.

[0050] According to further advantageous aspects of the invention, the inspection method of the invention comprises one or more characteristics considered individually or in all technically possible combinations:

[0051] -When performing the comparison step:

[0052] - using the set of first velocity values ​​and the set of second velocity values ​​with a nominal accuracy if all first velocity values ​​and second velocity values ​​agree with each other;

[0053] - if one of the first velocity values ​​is inconsistent with the other first velocity values ​​and the second velocity values, and the second velocity values ​​are consistent with each other and with respect to the other first velocity values, then the other first velocity values ​​and all the second velocity values ​​are used with nominal accuracy;

[0054] - if the first velocity values ​​are inconsistent with each other and none of them are consistent with second velocity values ​​that are consistent with each other, using the first velocity values ​​with decreasing precision and the second velocity values ​​with nominal precision;

[0055] - if all first velocity values ​​agree with one another but do not agree with second velocity values ​​that agree with one another, using the set of first velocity values ​​and the set of second velocity values ​​with nominal accuracy, while indicating doubt about the provided values;

[0056] The speed value is not used in other cases.

[0057] The present invention also relates to an angle of attack detector capable of measuring the angle of attack of an airflow within a measuring area, and comprising a rotating element, which can be rotated around a rotation axis substantially perpendicular to the direction of the airflow under the influence of the airflow, and the rotating element defines an equilibrium position, in which the rotation of the rotating element around the rotation axis is stabilized by the airflow.

[0058] According to other advantageous aspects of the invention, the angle of attack sensor of the invention comprises one or more characteristics considered individually or in all technically possible combinations:

[0059] - an excitation motor capable of exciting the rotating element about its equilibrium position according to excitation characteristics, preferably, the excitation motor is an electric motor connected to a flywheel;

[0060] - stabilizing means, which stabilize the rotating element in its equilibrium position, the stabilizing means being mechanical or electrical in nature;

[0061] - The excitation motor has an electrical stabilization device;

[0062] - a sensor capable of generating angular measurements relative to the rotation of said rotating element;

[0063] - the rotating elements are blades directly exposed to the air flow;

[0064] The rotating element is comprised in a cone exposed to the air flow and symmetrical with respect to the rotation axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] These characteristics and advantages of the invention will become more apparent on reading the following description, which is provided by way of limiting example only and which is made with reference to the accompanying drawings, in which:

[0066] Figure 1 is a schematic diagram of an angle of attack detector according to the present invention;

[0067] Figure 2 According to the present invention Figure 1 A flowchart of a self-test method performed by an angle of attack detector;

[0068] Figure 3 is a set of Pitot tube detectors and a set of multiple similar Figure 1 A schematic diagram of an angle of attack detector of the angle of attack detector in FIG.

[0069] Figure 4 According to the present invention, the Figure 3 Flow chart of a method for inspecting a set of Pitot tube detectors. DETAILED DESCRIPTION

[0070] Figure 1 An angle of attack probe 10 according to the invention is shown.

[0071] The probe 10 is integrated, for example, in the front part of an aircraft fuselage 12 and allows the angle of attack of the aircraft to be measured locally.

[0072] In other words, the probe 10 allows the angle of attack to be measured in a measurement zone that is adjacent to the point of integration of the probe 10 on the aircraft fuselage 12 .

[0073] refer to Figure 1 The probe 10 comprises a fixed part having a support 15 which is immovably integrated in the fuselage 12 of the aircraft, and a movable part 16 which is rotatably mounted in the support 15 relative to an axis of rotation Z.

[0074] The axis Z is, for example, substantially perpendicular to the outer surface of the fuselage 12 and therefore perpendicular to the incident airflow during flight of the aircraft. Figure 1Indicated by the reference symbol F.

[0075] The movable part 16 includes a rotating element 21 , an excitation motor 22 , a stabilizing device 23 , and a sensor 24 .

[0076] The rotating element 21 is able to rotate the movable part 16 about the axis of rotation Z under the influence of the air flow F.

[0077] The rotating element 21 also defines an equilibrium position in which the rotation of the rotating element 21 about the axis of rotation Z is stabilized by the air flow F.

[0078] exist Figure 1 In the example of FIG. 1 , the rotating element 21 is directly exposed to the air flow F and therefore takes the form of a blade. Thus, in the example of the figure, the probe 10 is a vane probe.

[0079] According to another exemplary embodiment (not shown), the detector 10 is a detector with pressure difference equalization between two zones. In this case, the detector also comprises a symmetrical cone exposed to the air flow F and provided with slots in each zone. The cone comprises an inner partition rotatable according to the pressure difference in the zones. In this way, the rotating partition has a rotating element 21 within the meaning of the invention.

[0080] Excitation of the motor 22 allows causing rotation of the rotating element 21 according to a control signal.

[0081] In a preferred embodiment of the present invention, the excitation motor 22 is an electric motor connected to a flywheel, and is therefore an inertia motor.

[0082] According to another exemplary embodiment, the electric motor 22 is a torque motor comprising a rotor in the movable part 16 and a stator in the fixed part 15 .

[0083] However, using an inertia motor can avoid failure modes such as blocking or braking for a torque motor.

[0084] The stabilizing device 23 can stabilize the rotating element 21 about its equilibrium position.

[0085] These stabilizing devices may be mechanical or electrical in nature.

[0086] In a preferred embodiment of the invention, the stabilizing device 23 is essentially an electrical device, formed by the excitation motor 22. Thus, according to this exemplary embodiment, the inertial motor 22 can not only cause the rotation of the rotating element 21, but also stabilize it around its equilibrium position.

[0087] In a variant, the stabilizing device 23 is also an electrical device in nature, but is formed as a separate device from the excitation motor 22 .

[0088] The sensor 24 allows a measurement signal comprising the angle of rotation of the movable part 16 about the axis of rotation Z to be generated.

[0089] The sensor 24 may be mechanical in nature, such as an inertial gyroscope, or may be an electrical or optical sensor.

[0090] According to the present invention, the detector 10 further includes a processing module 30 connected to the motor 22 and the sensor 24 .

[0091] The processing module 30 allows the generation of control signals for the electric machine 22 and the reception of measurement signals generated by the sensor 24 .

[0092] In general, the processing module 30 allows for the execution of a self-test method 100 of the detector 10 , which will be described in more detail below.

[0093] To this end, the processing module 30 takes at least partly the form of software and / or a programmable logic circuit of the Field Programmable Gate Array (FPGA) type.

[0094] In the first case, the software is implemented using a processor and a memory, such as an existing on-board computer. The software is thus connected to the motor 22 and the sensor 24 via transmission means known per se.

[0095] In the second case, the software circuit may be arranged near the fixed part 15 of the detector, or may be arranged remote from the fixed part 15 .

[0096] Now refer to Figure 2 A self-test method 100 of the detector 10 is described. Figure 2 A flowchart showing its steps is shown.

[0097] For example, the method 100 is performed periodically or continuously during the flight of the aircraft. According to another example embodiment, the method is performed when explicitly requested by the pilot and the avionics system.

[0098] When executing step 110 of method 100, processing module 30 processes the excitation signal at different times t1, . . . , t n An angular excitation command of the rotating element 21 about its equilibrium position is generated.

[0099] For example, the excitation characteristics have the current value sent to the motor 22 at the corresponding moment. Therefore, these characteristics are, for example, in the form of an excitation vector Te, which has the following form:

[0100]

[0101] Advantageously, the excitation characteristic Te defines a sinusoidal excitation of the rotating element, preferably pseudo-random.

[0102] When executing step 120, the processing module 30 obtains the n An angular measurement relative to the rotation of the rotating element 21 and measured by the sensor 24 .

[0103] Then, the processing module 30 determines the first and second order time derivatives of these angle measurements to obtain the following measurement value matrix M:

[0104]

[0105] Then, when executing step 130 , the processing module 30 determines the parasitic torque applied to the rotating element 21 according to the values ​​obtained in steps 110 and 120 .

[0106] The parasitic torque comprises, for example, four components in the following form:

[0107]

[0108] in:

[0109] Tq3 is a third-order component called inertia component and corresponds to the abnormal moment of inertia, for example;

[0110] Tq2 is the second-order component called the damping component;

[0111] Tq1 is a first-order component called a proportional component and corresponds to, for example, a lift anomaly; and

[0112] Tq0 is a zero-order component called mechanical friction and unbalance component.

[0113] The physical meaning of these components comes from the rotation model of the rotating element 21, which takes the following form:

[0114]

[0115] in:

[0116] J,b is a coefficient that changes relatively little during the use of the detector;

[0117] K is a coefficient proportional to the square of the velocity of the air flow F; and

[0118] noise(t) is a type of aerodynamic noise.

[0119] Based on the above concepts, the last relation can also be written in matrix form as follows:

[0120] c=(M T M) -1 M T Te,

[0121] in:

[0122]

[0123] To determine the components Tq3 and Tq2 , it is assumed that the coefficients J and b are known or can be determined by calibration and do not vary significantly during operation of the detector 10 .

[0124] Therefore, using the values ​​obtained in the previous steps, the components Tq3 and Tq2 can be determined directly.

[0125] The component Tq0 is determined by minimizing the aerodynamic noise.

[0126] To this end, when executing step 140 , the processing module 30 acquires data related to aerodynamic noise, for example from an external sensor (such as an inertial unit of the aircraft).

[0127] Then, when executing step 145 , the processing module 30 adjusts the excitation characteristic Te to reduce noise, thereby executing steps 110 and 120 again.

[0128] To determine the component Tq1 , the processing module 30 performs a first mechanized operation or a second mechanized operation.

[0129] According to a first mechanization operation, the component Tq1 is determined using at least one consistent speed value.

[0130] In this case, the processing module 30 executes step 150 , during which the processing module 30 acquires at least one value of the velocity modulus of the airflow F, called the coincident velocity, from a measuring device substantially separated from the detector.

[0131] Preferably, the measuring device is another angle of attack probe or a set of pitot tube probes, preferably the set of pitot tube probes comprises a plurality of pitot tube probes and a plurality of static pressure probes whose measured values ​​are consistent with each other. Therefore, in this case, the consistent speed is determined as the pressure speed determined by the set of pitot tube probes.

[0132] If multiple sources are present, the consensus velocity is preferably described by its mean, variance, number of sources and expected accuracy.

[0133] Then, using the consistent speed, the processing module 30 determines the coefficient K and determines the component Tq1 based on the coefficient.

[0134] According to a second mechanized operation, the processing module 30 sets a value Tq1 and determines, from this value Tq1 , a value of the velocity modulus of the airflow F known as the extrapolated velocity.

[0135] Advantageously, the first mechanized operation and the second mechanized operation may be repeated multiple times.

[0136] In this case, at the end of step 150 , the processing module 30 compares the coincident speed according to the first mechanized operation with the extrapolated speed according to the second mechanized operation and compares the value of the component Tq1 obtained according to the first mechanized operation with the value of the component Tq1 for the second mechanized operation.

[0137] If these comparisons are within a predetermined likelihood range, the processing module 30 establishes appropriate operating criteria to use these values ​​and the consistent speed. Otherwise, the processing module 30 repeats the first mechanized operation and the second mechanized operation.

[0138] When executing step 160 , the processing module 30 compares at least one component of the parasitic torque Tq with at least one predetermined threshold value.

[0139] Preferably, when performing this step, the processing module 30 compares each component of the parasitic torque Tq with at least one predetermined threshold.

[0140] Then, when executing step 170 , the processing module 30 diagnoses a fault of the detector when at least one component of the parasitic torque Tq exceeds a corresponding threshold value during the execution of step 160 .

[0141] When a fault is diagnosed, the processing module 30 issues an alert, for example, to the pilot or any other avionics system.

[0142] Advantageously, according to the invention, by identifying the component of the parasitic torque Tq that has exceeded a corresponding threshold value, the nature of the fault can be determined.

[0143] In particular, when it comes to the component Tq0, the fault may be due to friction or imbalance of the corresponding detector mass.

[0144] When it concerns the component Tq1 , the fault may correspond to an anomaly in the aerodynamic lift of the blade: the blade is broken or deformed, or it is covered with ice.

[0145] Ice and cracking conditions can also be detected by the inertial component Tq3.

[0146] For a given detector, since typically two detectors cannot deform in the same way, the deformation can be easily diagnosed using data from other detectors.

[0147] Finally, the component Tq2 exceeding the corresponding threshold value means that the damping of the blade is abnormal.

[0148] It can be seen that the self-test method according to the invention allows the self-test function of the detector 10 to be implemented during flight of the aircraft, without using data from other angle of attack detectors.

[0149] This allows diagnostics to be performed without using majority voting, providing the required level of safety while maintaining a structure with two detectors. The device also strengthens the integrity and availability of structures with more than two detectors, since the fault localization it allows greatly enhances the location of majority voting.

[0150] This device allows checking information from other probes used by the aircraft, in particular from a Pitot tube probe that allows measuring the pressure velocity of the air flow F.

[0151] In fact, typically, an aircraft includes a measurement group consisting of a plurality of angle of attack probes and a measurement group consisting of a pitot tube probe.

[0152] Figure 3 A group of multiple angle of attack detectors A1, ..., A N An angle of attack detector VI and a group of multiple Pitot tube detectors P1, ..., P M The set of Pitot tube probes VP also includes a plurality of static pressure probes (not shown) capable of measuring a pressure called static pressure.

[0153] This set of Pitot tube probes thus allows the pressure velocity of the air flow F to be measured using total pressure values ​​and static pressure values.

[0154] Because it allows to carry out the self-test method as described above, each angle of attack sensor A1, ..., A n Similar to the angle of attack probe 10 described previously.

[0155] Figure 3 Also shown is a check module 190 which is at least partially in the form of software and / or a programmable logic circuit of the FPGA type.

[0156] The checking module 190 allows checking the integrity of the data provided by the two sets of detectors VI and VP. For this purpose, the following steps are performed: Figure 4 Description of the inspection method 200, Figure 4 A flow chart showing the steps of the inspection method 200 is shown.

[0157] When the processing module 30 of each angle of attack detector does not detect the angle of attack detectors A1, ..., A2 after executing the self-test method, n This inspection method is performed when an operation failure occurs.

[0158] Furthermore, it was initially considered that the components of the wind speed measuring device, namely the pitot tube probes P1, ..., P associated with the static pressure probes M and pressure measuring means associated or not with the lidar, indicating a velocity value of the “pressure-velocity” type for the air flow F, which is hereinafter referred to as the first velocity value.

[0159] In this article, the term "air velocity" or "air speed" refers to the "pressure velocity" calculated solely from the values ​​provided by the pitot tube probe and the static pressure probe.

[0160] By itself, pressure velocity may also be referred to as conventional velocity or "conventional air speed" or "CAS." In particular, this pressure velocity should not be confused with true velocity or "true air speed" or "TAS," which indicates the average speed of air molecules.

[0161] When executing the initial step 210, the inspection module 190 obtains the Pitot tube detectors P1, ..., P M and / or all first speed values ​​indicated by the lidar.

[0162] When executing the same step, the checking module 190 also obtains the angle of attack detectors A1, ..., A2 generated by the group of angle of attack detectors A1, ..., A3 in step 130. N The processing module 30 determines the velocity value of the airflow F.

[0163] Each velocity value is hereinafter referred to as a second velocity value.

[0164] When step 220 is subsequently executed, the checking module 190 compares the second speed value with the first speed value, and after the comparison, uses the speed value to indicate the speed of the airflow F.

[0165] In this comparison, there are a number of possible scenarios.

[0166] In particular, when all of the first velocity values ​​and the second velocity values ​​are consistent with each other, the checking module 190 maintains the set of first velocity values ​​and the set of second velocity values ​​at the nominal accuracy.

[0167] When one of the first speed values ​​is inconsistent with the other first speed values ​​and the second speed values, and the second speed values ​​are consistent with each other and with respect to the other first speed values, the checking module 190 maintains the other first speed values ​​and all the second speed values ​​at the nominal accuracy.

[0168] When the first speed values ​​are inconsistent with each other and the first speed values ​​are inconsistent with the second speed values ​​that are consistent with each other, the checking module 190 keeps using the first speed values ​​with degraded precision and uses the second speed values ​​with nominal precision.

[0169] When all first velocity values ​​are consistent with each other, but inconsistent with second velocity values ​​that are consistent with each other, the review module 190 maintains the set of first velocity values ​​and the set of second velocity values ​​at a nominal accuracy, while indicating a question about the provided values.

[0170] In all other cases, the speed value is not used by the checking module 190 .

[0171] When step 230 is subsequently executed, the checking module 190 transmits the maintained speed value (and optionally its accuracy) to the pilot or any other avionics system.

[0172] It can therefore be seen that the inspection method 200 of the present invention allows all Pitot tube probes to be inspected, because of all the components of the wind speed measurement system typically mounted on an aircraft, the Pitot tube probe is the most difficult component to establish integrity in flight given its environment, which reflects the unique advantages of the present invention.

Claims

1. A self-testing method (100) for an angle of attack probe (10), the angle of attack probe (10) being capable of measuring the angle of attack of an airflow (F) within a measurement region and comprising a rotating element (21), the rotating element (21) being rotatable under the influence of an airflow about a rotation axis (Z) substantially perpendicular to the direction of the airflow (F), the rotating element (21) defining an equilibrium position, in which the rotation of the rotating element (21) about the rotation axis (Z) is stabilized by the airflow (F); The method (100) comprises the following steps: - (110) controlling the angular excitation of the rotating element (21) about its equilibrium position according to a known excitation characteristic (Te), the excitation characteristic (Te) defining a sinusoidal excitation of the rotating element; - (120) obtaining an angular measurement relative to the rotation of the rotating element (21); - (130) determining a parasitic torque applied to the rotating element based on the angle measurement and the excitation characteristic (Te); - (160) comparing at least one component of the parasitic torque to at least one predetermined threshold; - (170) when said component exceeds said predetermined threshold, indicating that a fault in the operation of said angle of attack sensor (10) has been detected.

2. The self-test method (100) according to claim 1, characterized in that: The parasitic torque is determined using a transfer function describing the rotation of the rotating element (21) in the presence of a parasitic torque, the parasitic torque being defined by an inertia component (Tq3) such as an abnormal moment of inertia, a damping component (Tq2), a proportional component (Tq1) such as an abnormal aerodynamic torque, and a component (Tq0) selected from a friction component and an unbalance component of the mass.

3. The self-test method (100) according to claim 2, characterized in that: The inertia component (Tq3), the damping component (Tq2), the proportional component (Tq1) and one component (Tq0) selected from the friction component and the imbalance component are determined by subtracting a predetermined portion of the maximum normal torque in its likelihood domain and identifying the parasitic torque portion corresponding to each respective component.

4. The self-test method (100) according to claim 1, characterized in that: The method further comprises the step (150): obtaining at least one value of the air flow velocity modulus, the at least one value being referred to as the consistent velocity, from a measuring device substantially separated from the angle of attack probe (10); The measuring device is another angle of attack probe or a speed measurement group including one or more pitot tube probes and / or one or more lidars.

5. The self-test method (100) according to claim 4, characterized in that: determining the parasitic torque using a transfer function describing the rotation of the rotating element (21) in the presence of the parasitic torque, the parasitic torque being defined by an inertia component (Tq3) such as an abnormal moment of inertia, a damping component (Tq2), a proportional component (Tq1) such as an abnormal aerodynamic torque, and a component (Tq0) selected from a friction component and an unbalance component of the mass, and determining the proportional component (Tq1) and the pressure velocity of the airflow relative to each other using a first mechanized operation or a second mechanized operation; According to the first mechanized operation, substituting the uniform speed into the transfer function, determining the proportional component (Tq1) with the other components of the parasitic torque; According to the second mechanization operation, the proportional component (Tq1) is determined by a predetermined value, and a pressure speed value called extrapolation speed is determined using a set of components of the parasitic torque; In one aspect, comparing a consistent speed according to the first mechanized operation with an extrapolated speed according to the second mechanized operation, On the other hand, the proportional component (Tq1) according to the first mechanized operation is compared with the proportional component (Tq1) according to the second mechanized operation, If the comparison is within a predetermined likelihood region, appropriate operating criteria are established.

6. The self-test method (100) according to claim 1, characterized in that: The frequency of the sinusoidal excitation is a pseudo-random frequency.

7. The self-test method (100) according to claim 1, characterized in that: The following steps are also included: -(140) acquiring data related to aerodynamic noise; -(150) adjusting the excitation characteristics according to the acquired data related to aerodynamic noise.

8. A method (200) for checking the pressure velocity of an air flow (F) provided by a set of Pitot tube probes (VP), the set of Pitot tube probes comprising a plurality of Pitot tube probes (P1, ..., P M ) and a plurality of static pressure detectors, wherein the group of Pitot tube detectors (VP) is capable of providing airflow pressure velocity values, which are referred to as first velocity values, and can be obtained by using the pressure values ​​from the Pitot tube detectors (P1, ..., P M ) and the value of the static pressure detector; The inspection method (200) is implemented by using a group of angle of attack detectors (VI), wherein the group of angle of attack detectors (VI) comprises a plurality of angle of attack detectors (A1, ..., A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A N ), each angle of attack detector (A1, ..., A N ) is capable of measuring the angle of attack of the airflow (F), and comprises a rotating element (21) and a processing module (30), the rotating element (21) rotating around a rotation axis (Z) under the influence of the airflow (F), the processing module (30) being capable of executing the self-test method (100) according to claim 5; When each angle of attack detector (A1, ..., A N ) processing module (30) performs the self-test method (100) and then fails to detect the angle of attack detector (A1, ..., A N ) when an operation failure occurs, executing the inspection method (200); The inspection method (200) comprises the following steps: -(210) obtains the angle of attack detectors (A1, ..., A N ) processing module (30) determines the pressure velocity value, each of which is referred to as a second velocity value; -(220) comparing the second velocity value with the first velocity value and determining from these values ​​a velocity value representing a pressure velocity of the airflow; -(230) Transmit the speed value used and its accuracy.

9. The inspection method (200) according to claim 8, characterized in that: When performing the comparison step (220): - using the set of first velocity values ​​and the set of second velocity values ​​with a nominal accuracy if all first velocity values ​​and second velocity values ​​agree with each other; - if one of the first velocity values ​​is inconsistent with the other first velocity values ​​and the second velocity values, and the second velocity values ​​are consistent with each other and with respect to the other first velocity values, then the other first velocity values ​​and all the second velocity values ​​are used with nominal accuracy; - if the first velocity values ​​are inconsistent with each other and none of them are consistent with second velocity values ​​that are consistent with each other, using the first velocity values ​​with decreasing precision and the second velocity values ​​with nominal precision; - if all first velocity values ​​agree with one another but do not agree with second velocity values ​​that agree with one another, using the set of first velocity values ​​and the set of second velocity values ​​with nominal accuracy, while indicating doubt about the provided values; The speed value is not used in other cases.

10. An angle of attack probe (10) capable of measuring the angle of attack of an airflow (F) in a measurement area, and comprising a rotating element (21), the rotating element (21) being rotatable under the influence of the airflow (F) about a rotation axis (Z) substantially perpendicular to the direction of the airflow (F), the rotating element (21) defining an equilibrium position, in which the rotation of the rotating element (21) about the rotation axis (Z) is stabilized by the airflow (F); The angle of attack detector (10) is characterized in that it also includes a processing module (30) capable of implementing the self-test method (100) according to claim 1.

11. The angle of attack detector (10) according to claim 10, characterized in that: The invention also comprises an excitation motor (22), wherein the excitation motor (22) can excite the rotating element (21) around its equilibrium position according to an excitation characteristic (Te), and the excitation motor (22) is an electric motor connected to a flywheel.

12. The angle of attack detector (10) according to claim 10, characterized in that: Also included is a stabilizing device (23) for stabilizing the rotating element (21) in its equilibrium position, the stabilizing device (23) being mechanical or electrical in nature.

13. The angle of attack detector (10) according to claim 12, characterized in that: It also includes an excitation motor (22), which can excite the rotating element (21) around its equilibrium position according to an excitation characteristic (Te), and the excitation motor (22) is an electric motor connected to a flywheel, and the excitation motor (22) has an electric stabilization device (23).

14. The angle of attack detector (10) according to claim 10, characterized in that: Also included is a sensor (24) capable of generating an angular measurement relative to the rotation of the rotating element (21).

15. The angle of attack detector (10) according to claim 10, characterized in that: The rotating element (21) is a blade directly exposed to the air flow (F).

16. The angle of attack detector (10) according to claim 10, characterized in that: The rotating element (21) is contained in a cone exposed to the air flow (F) and symmetrical with respect to the rotation axis (Z).

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