GB2540799A

GB2540799A - Method of indicating a status of a device on an aircraft

Info

Publication number: GB2540799A
Application number: GB1513296.2A
Authority: GB
Inventors: Pavaskar Anand; J Wood Christopher; Cipullo Alessio; Barad Kayvon
Original assignee: Airbus Operations Ltd
Current assignee: Airbus Operations Ltd
Priority date: 2015-07-28
Filing date: 2015-07-28
Publication date: 2017-02-01
Also published as: GB201513296D0

Abstract

A device on an aircraft is monitored to detect a fault or other change of status of the device 2 in response to which a light source 32 is operated to provide a telltale status indication which can be discerned by a human, status information related to the change of status is also generated, a portable receiver 40 is moved into proximity with the light source 32, and the light source 32 is operated to transmit the status information to the portable receiver 40 via free space by means of modulated light which is modulated with the status information. The change in status may indicate a fault, itself indicated by the signal from a sensor 7-11. The receiver 40 include a photodiode 41 and may de-modulate the light and store or display the status information. The modulated light may form the telltale indication or may be in a different part of the spectrum from the telltale indication. The light source 32 may a light emitting diode. Light guides such as optical fibres 60, 61 may be provided. A further light source 50 and receiver photodiode 51 may provide a return communication channel.

Description

METHOD OF INDICATING A STATUS OF A DEVICE ON AN

AIRCRAFT

FIELD OF THE INVENTION

[0001] The present invention relates to method of indicating a status of a device on an aircraft, and related apparatus.

BACKGROUND OF THE INVENTION

[0002] A telltale light is a known method of indicating a status of a device on an aircraft. An example is described in US8466788. A computer comprises a BITE (Built In Test Equipment) automatic test system, meeting avionics standards which is integrated into the avionics computers, and is suitable for transmitting an error message in the event of failure of said computer so as to turn on an error telltale light at cockpit level.

[0003] US6483865 discloses a wireless communication system for transmitting and receiving radio frequency (RF) signals inside an enclosure such as a hull of a torpedo, autonomous underwater vehicle, or aircraft, an automotive body, or a test equipment enclosure.

[0004] The use of optical communications in an aircraft cabin is known - for instance in: [1] S. Dimitrov , H. Haas , M. Cappitelli and M. Olbert "On the throughput of an OFDM-based cellular optical wireless system for an aircraft cabin", Proc. Eur. Conf. Antennas and Propagation (EuCAP 2011), 2011; and [2] N. Schmitt, "Wireless optical NLOS Communication in Aircraft Cabin for In-flight Entertainment," in Proc. of ESA 1st Optical Wireless Onboard Communications Workshop, Noordwijk, Netherlands, 29-30 Sep. 2004.

[0005] An aircraft data transmission network employing optical wireless communication is disclosed in US2012/0134679.

SUMMARY OF THE INVENTION

[0006] A first aspect of the invention provides a method of indicating a status of a device on an aircraft, the method comprising: in response to a change of status of the device, operating a light source to provide a telltale status indication which can be discerned by a human; generating status information related to the change of status; moving a portable receiver into proximity with the light source; and operating the light source to transmit the status information to the portable receiver via free space by means of modulated light which is modulated with the status information.

[0007] The invention uses a single light source to provide two functions - providing a telltale status indication, and also acting as a carrier for status information to provide further information about the device to a portable receiver. The use of only a single light source provides a light and compact system. The transmission via free space enables the status information to be acquired easily without having to make a physical connection to the portable receiver. This may be important if the device is at an inaccessible location. The use of light rather than radio frequency (RF) radiation makes the method less likely to interfere with other aircraft systems.

[0008] The change of status may be determined without monitoring the device. For instance the change of status may be triggered by a timer which automatically indicates that the device is due for a service. However more typically the method further comprises monitoring the device to detect the change of status of the device. For instance the device may be monitored to detect a number of operation cycles performed by the device, and after a preset number of cycles have been performed then the status of the device is changed to indicate that it is due for a service. Alternatively the change of status of the device may be indicative of a fault in the device. In this case monitoring the device to detect the change of status typically comprises operating a sensor to generate a sensing signal; and monitoring the sensing signal to detect the fault in the device. The sensing signal may be indicative of an operating condition of the device, such as temperature, voltage, torque or humidity. The fault may be a hardware fault or a software fault.

[0009] The device may be an actuator, fuel pump, valve or wing concentrator for example.

[0010] Typically the modulated light is demodulated at the portable receiver to extract the status information. The status information can then optionally be stored or displayed at the portable receiver. Alternatively the modulated light may be forwarded by the portable receiver without being demodulated.

[0011] The light source may emit telltale light to provide the telltale status indication. The telltale status indication may be provided by the presence of such telltale light, by a change of colour in light emitted by the light source (for instance a change from a green light to a red light) or by a change of intensity of light emitted by the light source (for instance a change from a constant light to a flashing light). Alternatively, a change from a presence of light to an absence of light from the light source may act as the telltale status indication.

[0012] In one embodiment the modulated light is the telltale light. In another embodiment the telltale light is in a different part of the spectrum to the modulated light, or transmitted at a different time to the modulated light. For instance the telltale light may be in a visible part of the spectrum and the modulated light may be in an invisible part of the spectrum.

[0013] The light source may comprise a light generator which is located at a position where telltale light from the light generator can be directly seen by a human. Alternatively the light source comprises a light generator for generating telltale light, the light generator is located at a position where the telltale light cannot be seen by a human, and the method further comprises guiding the telltale light from the light generator with a light guide, such as an optical fibre or mirror, to a position where the telltale light can be seen by a human.

[0014] The light source may be viewed directly, or it may be viewed via a window for example.

[0015] Preferably the modulated light is incoherent light (for instance from a light emitting diode) rather than coherent light (for instance from a laser). This makes damage to the human eye unlikely.

[0016] The aircraft may be a manned aircraft or an un-manned aircraft.

[0017] A further aspect of the invention provides apparatus for indicating a status of a device on an aircraft, the apparatus comprising: a light source; a portable receiver; and a control system configured to: in response to a detection of a change of status of the device, operate the light source to emit a telltale status indication which can be discerned by a human; generate status information related to the change of status; and operate the light source to transmit the status information to the portable receiver via free space by means of modulated light which is modulated with the status information.

[0018] Typically the portable receiver comprises a demodulator for demodulating the modulated light to obtain the status information.

[0019] Optionally the portable receiver further comprises apparatus for storing or displaying the status information.

[0020] Optionally the light source is a light emitting diode.

[0021] Preferably the light source is an incoherent light source such as a light emitting diode, rather than a coherent light source such as a laser. This makes damage to the human eye unlikely.

[0022] Optionally the light source comprises a light generator for generating telltale light, the light generator is located at a position where the telltale light cannot be seen by a human, and the apparatus further comprises a light guide, such as an optical fibre, for guiding the telltale light from the light generator to a position where the telltale light can be seen by a human.

[0023] Optionally the portable receiver is part of a portable device which further comprises a return light source which can communicate data via free space.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the invention will now be described with reference to the accompanying drawings, in which: [0025] Figure 1 shows an aircraft; [0026] Figure 2 shows apparatus according to a first embodiment of the invention; and [0027] Figure 3 shows apparatus according to a second embodiment of the invention. DETAILED DESCRIPTION OF EMBODIMENT(S) [0028] An aircraft 1 shown in Figure 1 comprises a valve actuator system 2 on a wing 3 of the aircraft. The valve actuator system 2, shown in detail in Figure 2, comprises a motor 4 which drives an output shaft 5. The motor 4 and output shaft 5 are housed in a casing 6. The system 2 has sensors 7, 8 for measuring speed and torque of the output shaft 5, sensors 9, 10 for measuring temperature and voltage of the motor 4, and a sensor 11 for measuring humidity within the casing 6. Further sensors may be provided if required.

[0029] The motor 4 is controlled by a controller 20 via a control line 21. The sensors 7-11 generate sensing signals which are input to the controller 20. The controller 20 runs "Built In Test Equipment" (BITE) logic which analyses the sensing signals and determines a status of the motor 4, shaft 5 and housing 6 (which will collectively be referred to below as "the device"). The status of the device may be OK, but a change in the sensing signals may lead to detection of a fault in the device such as: over temperature, jammed motor, illegal commands, short circuit, open circuit, software fault etc.

[0030] A memory 22 stores various information such as number of hours operated, time since last maintenance, part number etc. When a fault is detected by the controller 20, then fault information about the fault is stored in the memory 22. The fault information indicates the nature of the fault and provides further information about the fault. For instance if the fault is an "over temperature" fault, then the fault information may be: "Fault: over temperature; Max temperature reading: 100°C; Date and Time of Max temperature reading: 10/07/2015; 12.45".

[0031] A data line 12 from the controller 20 leads to a modem 30. The modem 30 leads to a power controller 31 which drives a light source 32 such as a light-emitting diode (LED). The power controller 31 and modem 30 are connected to a power source 35 via a power line 33 and an AND gate 36. When the status of the device is OK, then the controller 20 opens a switch 34 in a control line 37 to an open position shown in Figure 2 so that the signal on the control line 37 goes low and the AND gate 36 disconnects the modem 30 and power controller 31 from the power source 35, causing the power controller 31 to power-down. Therefore when the status of the device is OK, no light is emitted by the light source 32.

[0032] When the controller 20 detects a fault, then the switch 34 is closed and the light source 32 is energised by the power controller 31 to emit visible telltale light. In this example, the light source 32 is an LED which emits white light over a range of wavelengths which can be discerned by a human, and hence acts as a telltale fault indication. Note that in this example, the light source 32 is off when there is no fault, and turned on when there is a fault.

[0033] At the same time as the light source 32 is turned on to emit the telltale light, the fault information stored in the memory 22 is also output on the data line 12 and transmitted by modulating the telltale light with the fault information. In other words, the light emitted by the light source 32 acts simultaneously as a telltale fault indication that there has been a fault, and as a modulated carrier for the fault information.

[0034] Optionally the telltale light may flash on and off slowly - at a rate which is sufficiently slow to be discerned by a human. This may be more prominent than a constant intensity telltale light. Optionally the light may be on with constant intensity (i.e. not flashing) when the status of the device is OK, but switched to a slowly flashing light to provide a telltale fault indication.

[0035] The modulation of the light, to transmit the fault information, is typically at a rate which is higher than can be discerned by a human.

[0036] When the light source 32 is emitting telltale light, then this will be visible to aircraft maintenance crew, and prompts the crew to move a portable hand-held reader 40 into proximity with the light source as shown in Figure 2. The reader 40 has a photodiode 41 and a modem 42. The light source 32 is repeatedly transmitting the fault information, and once the reader 40 is sufficiently close, the photodiode 41 detects the modulated telltale light via free space 44 to provide a detection signal which is demodulated by the modem 42 to extract the fault information which is displayed to the maintenance crew on a screen 43.

[0037] The telltale light provides a visual indication, discernible by a human, that there is some kind of fault in the device, but does not distinguish between different types of fault. So for example if the fault is an over temperature fault, or a jammed motor, there is no difference in the nature of the telltale fault indication (i.e. it is provided by a constant intensity white light). On the other hand the fault information which is transmitted by modulation of the telltale light provides further information about the fault. So for instance the fault information may simply indicate the nature of the fault (for instance "over temperature" or "jammed motor") or it may provide further information about the fault (such as time, temperature, voltage etc).

[0038] The reader 40 can also communicate data to the controller 20 by means of a light source 50 on the reader 40 and a photodiode 51 on the system 2 which also communicate via free space 44. By way of example, this return communication channel may be used by the reader 40 to request certain data from the memory 22, or to upload software updates to the controller 20.

[0039] In the example above, the light source 32 is turned off when there is no fault, and turned on when there is a fault. In another example, the light source 32 may be always turned on, but its colour changed depending on the status of the device. For example if the status is OK, then the light is green and if a fault is detected then the light becomes red - the red colour acting as a telltale fault indication of the fault.

[0040] In the above examples the visible telltale light is modulated in accordance with the fault information. In other words the same visible light (white or red, constant or flashing) is used to provide a telltale fault indication and also as a carrier for the fault information. In another example the fault information may be carried by modulated light in one part of the spectrum (which may be visible or non-visible) and the telltale light provided by light in a different (visible) part of the spectrum. So, for example, if a fault is detected then the light source 32 may emit visible telltale light (white or red, constant or flashing) to provide a telltale fault indication of the fault, and the same light source simultaneously emits infra-red light which is modulated with the fault information. So in this example the two types of information (the telltale fault indication and the fault information) are transmitted by the light source 32 simultaneously by frequency-division multiplexing.

[0041] In the above examples, the light source 32 emits visible light (white or red, constant or flashing) to provide the telltale fault indication. In another example, when the status of the device is OK then the light source emits visible light, and when a fault is detected then the light source 32 is turned off. So in this example, the telltale fault indication is provided by an absence of visible light, and the fault information is transmitted by modulated infra-red light.

[0042] In the example of Figure 2 it is assumed that the LED 32 is mounted at a position where the LED 32 is visible so the telltale light can be seen directly. However this may not be possible - in other words the LED 32 may be hidden within the aircraft wing behind a skin panel, or in some other position where the telltale light cannot be seen directly. In the example of Figure 3 an optical fibre 60 is provided to act as a light guide for guiding telltale light from the LED 32 through a skin panel 61 to a position on an exterior of the aircraft where the light can be seen by the maintenance crew, and received by the portable reader 40 over the air gap 44. Similarly the return path comprises an optical fibre 62.

[0043] In summary, the apparatus described above provides an improved system for indicating a status of a device 4-6 on an aircraft. The sensors 7-11, controller 20, data line 12, modem 30 and power controller 31 collectively provide a monitoring and control system configured to provide a number of functions. Firstly, the monitoring and control system monitors the device to detect a fault using BITE logic. Secondly, the monitoring and control system operates the light source 32 to emit visible telltale light which can be discerned by a human in response to a detection of a fault. Thirdly, the monitoring and control system generates fault information about the fault, which is optionally stored in the memory 22. Fourthly, the monitoring and control system operates the light source 32 to transmit the fault information to the portable reader 40 via free space by means of light which is modulated with the fault information.

[0044] In the example given above, the monitoring and control system monitors the device to detect a fault in the device, and this triggers the generation of a telltale fault indication. In an alternative embodiment of the invention, the apparatus may instead be used to indicate that the device is due for a routine service rather than to indicate the presence of a fault. For instance a timer may measure the time since the last service of the device, and a change of status (to a status of "SERVICE DUE") is triggered automatically when the timer indicates that a certain period of time has elapsed since the last routine service. Alternatively the number of operational cycles of the actuator may be monitored, and after a preset number of cycles have been performed then a similar change of status (to a status of "SERVICE DUE") is triggered automatically.

[0045] When the status of the device changes to indicate that the device is due for a routine service, then the monitoring and control system operates the light source 32 to emit visible telltale light which can be discerned by a human and prompts maintenance crew to service the device. The monitoring and control system also generates status information related to the change of status - for instance an indication of the number of operational cycles since the last service, the date of the last service, the maximum temperature of the device since its last service etc. The monitoring and control system then operates the light source 32 to transmit the status information to the portable reader 40 via free space by means of light which is modulated with the status information. This assists the maintenance crew in the servicing of the device.

[0046] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A method of indicating a status of a device on an aircraft, the method comprising: in response to a change of status of the device, operating a light source to provide a telltale status indication which can be discerned by a human; generating status information related to the change of status; moving a portable receiver into proximity with the light source; and operating the light source to transmit the status information to the portable receiver via free space by means of modulated light which is modulated with the status information.

2. The method of claim 1, further comprising monitoring the device to detect the change of status of the device.

3. The method of claim 2, wherein the change of status of the device is indicative of a fault in the device.

4. The method of claim 3, wherein monitoring the device to detect the change of status comprises operating a sensor to generate a sensing signal; and monitoring the sensing signal to detect the fault in the device.

5. The method of any preceding claim, further comprising demodulating the modulated light at the portable receiver to extract the status information.

6. The method of claim 5, further comprising storing or displaying the status information at the portable receiver.

7. The method of any preceding claim, wherein the light source emits telltale light to provide the telltale status indication.

8. The method of claim 7, wherein the modulated light is the telltale light.

9. The method of claim 7, wherein the telltale light is in a different part of the spectrum to the modulated light.

10. The method of any preceding claim, wherein the light source comprises a light generator for generating telltale light, the light generator is located at a position where the telltale light cannot be seen by a human, and the method further comprises guiding the telltale light from the light generator with a light guide to a position where the telltale light can be seen by a human.

11. Apparatus for indicating a status of a device on an aircraft, the apparatus comprising: a light source; a portable receiver; and a control system configured to: in response to a change of status of the device, operate the light source to emit a telltale status indication which can be discerned by a human; generate status information related to the change of status; and operate the light source to transmit the status information to the portable receiver via free space by means of modulated light which is modulated with the status information.

12. The apparatus of claim 11, wherein the portable receiver comprises a demodulator for demodulating the modulated light to obtain the status information.

13. The apparatus of claim 12, wherein the portable receiver further comprises apparatus for storing or displaying the status information.

14. The apparatus of any of claims 11 to 13, wherein the light source is a light emitting diode.

15. The apparatus of any of claims 11 to 14, wherein the light source is an incoherent light source.

16. The apparatus of any of claims 11 to 15, wherein the light source comprises a light generator for generating telltale light, the light generator is located at a position where the telltale light cannot be seen by a human, and the apparatus further comprises a light guide for guiding the telltale light from the light generator to a position where the telltale light can be seen by a human.

17. The apparatus of claim 16, wherein the light guide comprises an optical fibre.