DE102019114463B4 - Overload and breakage monitoring method and system for an aircraft high-lift system - Google Patents

Abstract

Overload and breakage monitoring method for a high-lift system (1) of an aircraft (3), 1.2 wherein at two spaced locations (17, 18) of a drive train (7) of the high-lift system (1) measured values for rotation angle (φ1, φ2) by rotation angle sensors (11, 12). (28)1.5 is determined as an indicator for the loads present between the points at the time of twisting, characterized in that1.6 the computer calculates the twisting of an actuator (8) of the drive train (7) branching off from the main transmission train (28) or1.7 the computer (10) calculates the torsion over several elements (31, 34) of the branching off drive train (7).

Description

The invention relates to an overload and breakage monitoring method and system for a high-lift system of an aircraft according to the preamble of claim 1.

The high-lift system usually includes two subsystems, namely a landing flap system (flap system) with its landing flaps, which are also referred to as flaps, and a slat system (slat system) with its slat flaps, also referred to as slats. The landing flaps and the slat flaps are therefore parts of the aircraft structure and are therefore usually subject to the strict national and international approval regulations associated with aircraft construction, in particular the various strict national and international approval regulations associated with large aircraft construction. The high-lift system, which contains and moves the aforementioned flaps, is also subject to strict approval regulations. In large aircraft construction, the aircraft structure or the structural elements of an aircraft and systems, which can contain different structural elements, are subject to separate approval regulations.

Various approval authorities stipulate, among other things, that the following faults in particular must be recognized in the high-lift systems mentioned and that the system part affected by the fault be switched off and the high-lift system thereby switched to the so-called fail-safe state.

One of these error cases is the case of overload. "overload". The causes of this error are mostly cases of jamming, in which, for example, a foreign object is jammed in a drive train, in particular a rotary drive train of the high-lift system. This error can be caused in particular by jamming cases in which an object that was forgotten during maintenance work, for example, jams in a kinematic device of the drive train, for example in a rack and pinion system or in a lever system, which, for example, connects an actuator to one of the flaps mentioned above, such as a landing flap. An incorrectly adjusted high-lift system which, when actuated, reaches a stop, e.g. a stop of one of the actuators, can also lead to the above-mentioned case of overload.

Another of the error cases mentioned above is the breakage case. Disconnect, which can occur, for example, in the kinematics or in one of the kinematic devices between an actuator and a flap or also within an actuator, in particular within a drive path branching off from the main transmission to the flaps. Such a fracture can in particular result in a skew of the affected flap and can lead to a loss of this flap if the high-lift system is further actuated. One reason for this can be the comparatively high load within the remaining intact drive train section. In particular, the flap could be ripped off the aircraft, causing further serious damage to the aircraft and other catastrophic effects.

BACKGROUND OF THE INVENTION

It is known from the prior art that the above-mentioned two error cases, the case of overload and the case of breakage. to detect, although so far more than a single method and monitoring system has to be used.

From the WO 2013/002 874 A2 a so-called torque limiter is known, which is located in the actuators or the branching gears of the rotary drive train of the high-lift system. By means of a prestressed spring, this torque limiter can detect an overload and the drive train connected to the flaps can be decoupled from the landing flap or flaps or the slat flap or flaps. Torque limiters can thus protect the affected flaps and the associated structure of the aircraft.

Various systems for detecting fractures in the high-lift system are also known. A break in the main transmission is detected, for example, with a suitable sensor system, which is preferably attached to both outer ends of the main transmission. If such a break is detected, the safety brakes of the high-lift system are activated, i.e. the system is locked.

Systems for detecting breaks in the kinematics between the actuators and the flaps or in the branching drive path within the actuators from the main transmission to the flaps are also known. Most of these systems are based on a comparative travel measurement of the drive trains of the two driving actuators of a flap. A detection of the fracture can therefore only take place after a misalignment has occurred through further actuation of the high-lift system. However, a misalignment in turn causes very high loads in the remaining intact drive train of an actuator.

In the case of the earlier right named EP 3 549 859 A1 it is simply a matter of detecting and eliminating from within the transmission box tensioned moments of a drive unit (PDU). For this purpose, measurements of angles of rotation or angular speeds of rotation are carried out at at least three different points of the drive train and the sensors used for this purpose are arranged on the transmission shafts of the drive train. This publication only deals with the "jam" error (jamming that leads to overloading) within the main transmission starting from the drive unit (PCU or PDU). Also discussed is the relaxation of an overload through the PDU. However, the sensors used can neither detect an overload nor a break in the branching off drive trains from the gearboxes to the flaps.

It is also known to detect a load on an actuator at the input or at the output of the drive train, and thus to detect a break.

From the non-generic publication EP 3 404 395 A1 a test apparatus for testing a sensor arrangement outside the aircraft as part of maintenance work can be seen. The main load path of an actuator should be checked in a test environment.

The object of the invention is to provide an overload and break monitoring method in which breaks and overload situations can be detected in the drive train branching off either from the actuators or from the branching gears to the flaps.

A method and system according to independent claims 1 and 7 are proposed to solve the stated tasks.

Accordingly, as a first embodiment of the invention, an overload and breakage monitoring method for a high-lift system of an aircraft is proposed, wherein measured values are recorded by rotation angle sensors at two spaced-apart points of a drive train of the high-lift system, and a deviation of the measured values recorded at the first point from the simultaneously recorded measured values at the second point is determined by a computer.

According to the invention, the material- and shape-dependent torsional softness of at least one of the elements of the drive train is used to reliably detect the aforementioned errors. This is because the measured values recorded by means of the rotation angle sensors are rotational measured values which change in particular proportionally or in another connection known to those skilled in the art with the torsion between the two aforementioned points based on torsional softness. In particular, according to the invention, the torsional softness of a single element of the drive train, such as an actuator, can be measured.

In particular, the invention advantageously uses the fact that both in the event of an overload and in the event of a break, the loads that are transmitted to the various stages of the drive train change significantly and, in particular, abruptly.

Advantageously, both errors can be determined using a single method, in particular without any significant delay. As a further advantage of the invention, the above-mentioned torque limiters can be omitted and cost savings can thus be achieved.

Both error scenarios mentioned above can be recognized very quickly according to the invention. Possible catastrophic effects can be avoided, in particular when a fracture is detected which is associated with a flap misalignment (skew). Compared to the path measurement known in the prior art, the breakage can advantageously be reliably detected and avoided according to the invention even if the actuator remains intact.

If a warning signal is to be generated before a fracture and/or an overload occurs, a further embodiment of the invention can provide for the signals of the angle of rotation sensors to be evaluated even more thoroughly, for example by means of an in particular continuous FFT (Fast Fourier Transformation) signal analysis. Such a signal evaluation would be part of a currently discussed "health monitoring"; further increase safety during flight operations.

In a further embodiment, a relative torsion of the drive train is determined from the measured values as an indicator for the loads present between the points at the time of the torsion.

In a further embodiment, the torsion or the relevant measured value is based on the torsional softness of at least one element of the drive train from the following group: actuator, element of a transmission device, element of a branch transmission device.

In a further embodiment, the torsion or the relevant measured value is based on a combined torsional softness of two or more of the above group.

In a further embodiment, an overload signal is output when the deviation exceeds a predefined threshold value.

In a further embodiment, a breakage signal is output if a first derivative of the torsion over time (d/dt) exceeds a threshold value in terms of its magnitude (degrees/second).

In addition to the relative deviation of the recorded measured values, in a further aspect of the invention, their time profile and thus a load increase can also be recorded. In particular, a rapid increase in load can be reliably recognized as an overload situation when the threshold value is exceeded.

In a further embodiment of the invention, a signal for a break or an impending break is output when the deviation is greater than a second threshold value. It goes without saying that the first and the second threshold value can be identical. Even in the event of a break, the time recording mentioned above will lead to a reliable detection of this error case. In the event of a break, the increase or decrease in the measured deviation occurs comparatively quickly or abruptly. Expressed mathematically, the 1 derivation can be formed and evaluated from the recorded measured values.

If a break occurs, the first derivative mentioned makes a jump in the course of the measurement. This jump in turn can be detected by a threshold value.

The signal output can be used directly for an automatic shutdown of the affected system part or can be transmitted to a member of the flight crew, in particular a pilot, via an acoustic or visual display device.

The measured values recorded by the sensors are preferably measured values for angles of rotation.

In normal operation, a small amount of rotation between the two measuring points can be expected along the drive train, so comparatively small differences in the angle of rotation or deviations can be expected. When operating the flaps, for example when extending the flaps before landing or retracting the flaps after take-off, loads in a certain range are expected, depending on the flap position, flight speed and wind conditions. If these loads increased suddenly while the flaps were being extended, an overload situation can be assumed, caused, for example, by ice accretion or a broken and jammed metal object. The increase in load leads directly to a material- and shape-dependent torsion, with a certain torsional flexibility of the part of the drive train for the flaps located between the measuring points. This rotation detected by the rotation sensors can be detected in a computer with suitable, known algorithms and the system can be switched off and thus transferred to the so-called fail-safe state.

Likewise, the load profile can change relative to the loads that can be expected in normal operation in the event of a break. This change can be recognized as a fault using the invention and is reflected in abrupt changes in the torsion. This error case can be detected in particular with suitable algorithms and the system can then be transferred to the fail-safe state.

In a further exemplary embodiment, the pilot is clearly informed by a signal output device whether the error is due to a breakage or an overload.

In a further embodiment, a monitoring system for a high-lift system of an aircraft is proposed, the high-lift system having a plurality of flaps and at least one drive train that drives at least one of the flaps in rotation, the monitoring system having a first sensor and a second sensor, the first sensor at a first point in the drive train detecting a first measured value for a rotary adjustment at this point as a measure for load transfer, the second sensor at a second point on the high-lift system recording a second measured value for a rotary adjustment at this point Point recorded as a measure of a load transfer, with a deviation of the two recorded measured values from each other can be determined by a computer system.

The stated measured values of the sensors or angle of rotation sensors are sent to a suitable computer and evaluated there continuously or, in the case of digital computers, quasi-continuously, ie with a suitably high sampling rate. The computer preferably calculates the torsion of the branching drive path of an actuator or the torsion over several elements of the branching drive path. In a further aspect of the invention, any transmission ratios of transmission parts can be taken into account. The algorithms already mentioned above collect and store this continuously generated twist data in one or more memories and then evaluate them and switch off the system if threshold values or other comparative monitors are exceeded, thus putting it into a so-called fail-safe state.

In a preferred embodiment of the invention, the pilot is informed of a preferably automatic shutdown of the high-lift system and of the type of error detected by the system as an acoustic and/or visual signal.

• 1 eine schematische Ansicht eines Hochauftriebssystems,
• 2 eine schematische Anordnung eines Aktuators mit zwei Sensoren,
• 3 eine schematische Anordnung der Sensoren über mehrere Elemente eines abzweigenden Antriebspfades.
• 4 ein Blockschaltbild für einen Überlastfall für ein erfindungsgemäßes Überlast- und Bruch-Überwachungsverfahren und
• 5 ein Blockschaltbild für einen Bruchfall für ein erfindungsgemäßes Überlast- und Bruch-Überwachungsverfahren.

Further details and advantages of the invention become clear from the exemplary embodiments illustrated in the drawings. Show it

• 1 a schematic view of a high-lift system,
• 2 a schematic arrangement of an actuator with two sensors,
• 3 a schematic arrangement of the sensors over several elements of a branching drive path.
• 4 a block diagram for an overload case for an overload and breakage monitoring method according to the invention and
• 5 a block diagram for a breakage for an inventive overload and breakage monitoring method.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

1 shows schematically a high-lift system 1 for a right wing 2 of a large passenger aircraft 3.

The high-lift system 1 has a plurality of flaps 6 . At the wing leading edge of each wing 2 there are seven slat or leading edge flaps 4, so-called slats. Furthermore, each wing 2 has an outer and an inner landing flap 5, or flaps.

There are a total of four drive trains 7 for the flaps 6 in the aircraft 3, of which only the two drive trains 7 for the right wing 2 are shown schematically for reasons of clarity. 18 actuators 8 are also shown, which each adjust a flap 6 in pairs. The combination of an actuator and the connecting parts to form a flap is also referred to as a drive station.

Furthermore, braking systems are also present within the drive trains 7, of which a safety brake 23 of the right slat system and a safety brake 24 of the right landing flap system are shown. Part of a monitoring system 9 in the form of a computer 10 for control and monitoring is also shown. Supply lines and bus lines for the sensors in the form of angle of rotation sensors and the angle of rotation sensors themselves are not shown here. The actuators 8 shown are connected to drive motors in the form of drive units 26, for example in the form of electric motors and/or hydraulic motors, via further elements of the respective drive train, namely via gears 25 in the form of adjusting gears, branch and deflection gears. A total of four drive trains 7 with four drive units 26 are present for an aircraft according to this embodiment.

In the 1 a branching drive train is shown highlighted by an ellipse 27, which leads from the main transmission train 28 via a gearbox 25 in the form of a branch gearbox and the actuator 8 with a connecting element 29 to a flap 6, here the left side of the inner landing flap 5.

Overall, the rotations, in particular the angle of rotation positions, are detected at all drive stations, and consequently there are 36 angle of rotation sensors for the flaps of a wing in this exemplary embodiment. In a further embodiment, further angle of rotation sensors can additionally or alternatively also be provided for the gears.

Based on 2 can be explained by way of example where the sensors can be arranged. An actuator 8 with two sensors 11, 12 is shown schematically. Essentially, the actuator shown is divided into three stages, namely an input stage 13, a preliminary gear stage 14 and a main gear stage 15.

A through drive 19 is also shown, as well as a gear ratio 20 and a branch 21 of the main transmission level to the flap drive 20' in the form of a pinion 21.

A torsion V can be determined using two measurements, namely the angle of rotation φ1 at the input stage 13 and the angle of rotation φ2 at the output, where the following applies: $$\text{V}=\mathrm{\varphi }1-\mathrm{<figure-callout\; id="2"\; label="\phi "\; filenames="DE102019114463B4\_0004.png"\; state="\{\{state\}\}">\varphi </figure-callout>}2$$

It goes without saying that gear ratios lying between the measuring points can also be taken into account, for example as an additional factor.

In each of the three stages, the respective representative mass and stiffness is represented in particular by a spring symbol. The entrance level 13 has a first point 17 at which the sensor 11 detects an angle of rotation, and therefore a rotational measured value. The main transmission stage 15 has a second point 18 at which the sensor 12 detects an angle of rotation, and therefore a second rotational measured value.

The 3 shows a schematic arrangement of rotation angle sensors 11, 12 over several elements of a from in 1 Main transmission train 28 shown branching off drive train 7. Here is a rotation angle sensor 11 within a surrounded by a square 30 symbolically represented branch transmission 31 present and specifically still in the area of the drive train 7 of the main transmission. The torsional flexibility of this branch transmission 31 is represented by a spring symbol 32 . The branch transmission 31 is non-rotatably connected to an input transmission 34 by means of a branch transmission line 33 . More precisely, a gear wheel 35 of the branch transmission 31 and a gear wheel 36 of the input gear 34 are arranged in a rotationally fixed manner with respect to one another. Another rotation angle sensor 12 is present between the input gear 34 and the actuator 8 . In this arrangement, the sum of the torsional softness of branch transmission 31 and the torsional softness of input transmission 34, represented by spring symbol 32, is recorded and evaluated.

This in 4 The block diagram shown schematically represents the monitoring for the case of overload or jamming within the overload and breakage monitoring method according to the invention 2 and 3 Rotation angle sensor 11 shown schematically detected. At the same time, a second measured value φ2 of a rotation angle sensor of a second measuring point, such as that in 2 and 3 Rotation angle sensor 12 shown schematically detected and block 42 supplied. In a calculation unit, the torsion V is determined from the two measured values with V= ϕ1-ϕ2 and the amount with |V| = |ϕ1 - ϕ2| educated. Optionally, gear ratios for both measured values can also be used to calculate the twist, as is shown schematically using blocks 40 and 41, and the calculated twist V can thus be adjusted if necessary.

The absolute value of the torsion is then formed in block 43 and compared in a comparator block 44 with a predefined threshold value a. The comparison with the threshold value is carried out by a binary output from block 44, the binary value "0" being set or remaining for the status "no exceeding" and the binary value "1" being set for the event that the threshold value is exceeded.

The aforementioned binary values are output to a counter block 45, with an overload situation or a jam situation being assumed after a previously determined number of consecutive exceedances. The number mentioned depends in particular on the signal rate or the measuring frequency of the rotation angle sensors used.

The 5 shows a block diagram for a breakage within the overload and breakage monitoring method according to the invention. It goes without saying that both the breakage and, in particular, in 4 overload case outlined with the block diagram can be detected by means of the same hardware of the invention.

In contrast to the in 4 The block diagram shown is used to detect a fracture, the first derivative of twists calculated in block 42. The calculated values for at least two consecutive rotations over a period of time, for example the measurement interval, are considered, for example with (V2-VI/t2-tl), with a memory unit (not shown here) for storing the intermediate values, which can be stored in the unit degrees/second, for example, being used. The function obtained therefrom corresponds to the first derivation of the torsion over time (d/dt) and is formed in block 50, with a signal filter optionally being able to be used, which is shown as block 51. The absolute value of the first derivative is then formed in block 43 and compared in a comparator block 44 with a predefined threshold value b. The comparison with the threshold value b is again carried out by a binary output from block 44, the binary value “0” being set or remaining for the status “no exceeding” and the binary value “1” being set for the case when the threshold value is exceeded.

The aforementioned binary values are output to a counter block 45, a break being assumed after a previously determined number of consecutive exceedances. Here, too, the number mentioned depends in particular on the signal rate or the measuring frequency of the rotation angle sensors used.

The reference numbers used are for convenience only and should not be taken as limiting in any way, the scope of the invention being indicated by the claims.

Reference List

1

high lift system

2

wing

3

Airplane

4

slat flaps

5

flaps

6

Succeed

7

powertrain

8th

actuator

9

surveillance system

10

computer

11

angle of rotation sensor

12

angle of rotation sensor

13

entry level

14

gear precursor

15

gear main stage

16

feather icon

17

Job

18

Job

19

through drive

20

gear ratio

20'

damper drive

21

junction

21'

pinion

23

safety brake

24

safety brake

25

transmission

26

drive unit

27

ellipse

28

main transmission line

29

fastener

31

branch gearbox

32

feather icon

33

branch transmission line

34

input gear

35

gear

36

gear

40

block

41

block

42

block

43

block

44

comparator block

45

counter block

50

block

51

block

V

twist

ϕ1

angle of rotation

ϕ2

angle of rotation

a

threshold

b

threshold

Claims (12)

Overload and breakage monitoring method for a high-lift system (1) of an aircraft (3), 1.2 measured values for the angle of rotation (φ1, φ2) being recorded by angle of rotation sensors (11, 12) at two spaced-apart points (17, 18) of a drive train (7) of the high-lift system (1). 1.3 and a deviation V of the recorded measured values of the first point (17) from the simultaneously recorded measured values of the second point (18) is determined by a computer, 1.4 whereby a relative twisting of the main transmission line (28) is determined from the measured values 1.5 is determined as an indicator of loads applied between the points at the time of twisting,characterized, that 1.6 the computer calculates the rotation of an actuator (8) of the drive train (7) branching off from the main transmission train (28) or 1.7 the computer (10) calculates the torsion over several elements (31, 34) of the branching off drive train (7). Overload and Breakage Monitoring Procedures claim 1 , characterized in that the transmission ratios of transmission parts (25, 31, 34) are also taken into account. Overload and Breakage Monitoring Procedures claim 1 or 2 , The torsion being based on the torsional softness of at least one element of the drive train (28) from the following group: actuator (8), transmission device, branch transmission device. Overload and Breakage Monitoring Procedures claim 3 , where the twist is based on a combined torsional softness of two or more members of the group. Overload and breakage monitoring method according to any one of the preceding claims, wherein an overload signal is output if the deviation exceeds a predefined threshold value a. Overload and breakage monitoring method according to one of the preceding claims, wherein a breakage signal is output when a first derivative of the torsion V over time exceeds a threshold value b in terms of its magnitude. Monitoring system (9) for a high-lift system of an aircraft, the high-lift system having a plurality of flaps (6) and at least one drive train (7, 28) driving at least one of the flaps (6) in rotation, the monitoring system having a first sensor (11) and a second sensor (12), the first sensor (11) at a first point on the drive train (7, 28) detecting a first measured value for a rotary adjustment at this point as a measure of load transfer, wherein the second sensor (12) at a second point in the high-lift system records a second measured value for a rotational adjustment at this point as a measure of load transfer, it being possible for a computer system to determine a deviation between the two measured values recorded,characterizedthat the computer (10) calculates the twisting of an actuator (8) in the drive train (7) branching off from the main transmission train (28) or the twisting over several elements of the branching off drive train (7). surveillance system claim 7 , characterized in that the main transmission line (28) branching drive train (7) consists of a gear (25), the actuator (8) and a connecting element (29) to a flap (6) of the inner landing flap (5). surveillance system claim 7 or 8th , characterized in that the rotational angle positions are detected at all drive stations. surveillance system claim 7 , wherein the flaps (6) of the high-lift system are landing flaps (5) and/or slat flaps (4). Aircraft (2), having a monitoring system according to claim 9 . Computer program suitable for carrying out a monitoring method according to one of claims 1 until 6 .

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