AUTOMATED SAFETY SYSTEM FOR AIRCRAFT

Abstract

The invention is a self-contained, anti-collision safety system controller for high altitude, solar powered, unmanned aircraft. The controller acts as a backup to the primary safety system on the aircraft. It automatically turns on safety system equipment, such as a Mode S transponder and anti-collision lights when the aircraft descends below a pre-set pressure altitude. The pre-set altitude is chosen so that exceeds the altitude where other aircraft are operating and where collisions might occur. The controller measures the external air pressure to determine the aircrafts pressure altitude and activates/deactivates an internal switch between the power supply and the safety system equipment depending on whether the measured altitude exceeds the pre-set altitude level or not. The controller can be integrated into the exterior surface of an aircraft or internally within the airframe.

Claims

1. A safety system controller for an aircraft, the safety system controller comprising: a safety means; a power source for powering the safety means; a pressure detector for detecting air pressure; and a switch for activating the safety means, wherein the pressure detector is arranged to close the switch to activate the safety means when the air pressure exceeds a value indicative of a pre-set altitude.

2. The safety system controller according to claim 1, wherein the pressure detector is arranged to open the switch to deactivate the safety means when the air pressure decreases below a value indicative of the operating altitude of the aircraft being reached.

3. The safety system controller according to claim 2, wherein the switch is arranged electrically between the power source and the safety means.

4. The safety system controller according to claim 1, wherein the safety means comprises a transponder, a light source and a means for determining the location of the safety system controller.

5. The safety system controller according to claim 4, wherein the means for determining the location comprises a Global Navigation Satellite System (GNSS) receiver and antenna.

6. The safety system controller according to claim 4, wherein the safety system controller comprises a housing, wherein the housing comprises the power source, pressure detector, transponder and switch.

7. The safety system controller according to claim 6, wherein the light source, GNSS receiver and antenna, and a transponder antenna are connected to the power source and the transponder through an aperture in the housing.

8. The safety system controller according to claim 5, wherein the housing further comprises the light source, GNSS receiver and antenna and a transponder antenna.

9. The safety system controller according to claim 5, wherein the housing is permanently attached to an airframe of the aircraft using a low temperature adhesive.

10. The safety system controller according to claim 1, wherein the power source is a battery.

11. An aircraft comprising the safety system controller according to claim 1.

12. The aircraft according to claim 11, wherein the aircraft is configured to descend when a failure in a safety system is detected.

13. The aircraft according to claim 11, comprising a pressure detector tube extending to a point on the exterior surface of an airframe of the aircraft to allow the external air pressure to be sensed, the pressure detector tube being attached to the pressure detector and the switch.

14. The aircraft according to claim 11, wherein the aircraft is an unmanned solar-powered aircraft.

15. A method of activating a safety device for an aircraft, the method comprising: detecting air pressure external to the aircraft; closing a switch to activate a safety means if the air pressure is exceeds a value indicative of a pre-set altitude; and opening the switch to deactivate the safety means when the air pressure decreases below a value indicative of the operating altitude of the aircraft being reached.

16. The safety system controller according to claim 2, wherein the safety means comprises a transponder, a light source and a means for determining the location of the safety system controller.

17. The safety system controller according to claim 3, wherein the safety means comprises a transponder, a light source and a means for determining the location of the safety system controller.

18. The safety system controller according to claim 5, wherein the safety system controller comprises a housing, wherein the housing comprises the power source, pressure detector, transponder and switch.

19. The safety system controller according to claim 6, wherein the housing is permanently attached to an airframe of the aircraft using a low temperature adhesive.

20. The safety system controller according to claim 7, wherein the housing is permanently attached to an airframe of the aircraft using a low temperature adhesive.

Description

[0062] The invention is described by reference to two embodiments and the accompanying drawings in which:

[0063] FIG. 1 A safety system controller in an external pod

[0064] FIG. 2 A safety system controller adapted to fit internally within the aircraft

[0065] FIG. 3 A simple schematic of the safety system controller showing the pressure detector and switch.

[0066] FIG. 1 shows the preferred embodiment of the present invention which is a safety system controller which can be mounted on the external surface of a solar powered high altitude unmanned aircraft. The safety system controller consists of an outer aerodynamically shaped housing 7 containing a battery 1 power source, a pressure detector & switch 2, a pair of anti-collision lights 3, a Mode S ADS-B transponder with integrated Global Navigation Satellite System (GNSS) receiver 5, a transponder antenna 6 and a GNSS antenna 4. Further, the safety system controller comprises an outer aerodynamically shaped housing 7 containing a battery 1 power source, a pressure detector & switch 2, a pair of anti-collision lights 3, a Mode S ADS-B transponder with integrated Global Navigation Satellite System (GNSS) receiver 5, a transponder antenna 6 and a GNSS antenna 4. In other words, the safety system controller can have other components including for example wires.

[0067] The housing 7 is permanently attached to the airframe using a suitable low temperature adhesive and remains in place between flights. The housing is not air tight as the pressure detector 2 must be able to sense the external air pressure.

[0068] In the preferred embodiment the pressure detector 2 is a mechanical device which detects changes in the external air pressure and thereby measures the pressure altitude for the aircraft. Alternative implementation of the pressure detector would be a piezoelectric, solid state or a barometric pressure switch. Whichever implementation is chosen the detector reacts to the increase in air pressure by closing the switch at a pre-set altitude. The pressure detector is calibrated before flight so that the pre-set altitude corresponds to the upper flight level attainable by passenger carrying aircraft flying in controlled airspace.

[0069] During ascent, the altitude is less than the pre-set value for the detector it automatically closes the switch 2 that completes the electrical circuit show in FIG. 3 thereby connecting the of anti-collision lights 3, GNSS receiver 4 and the transponder 5 to the battery 1. These components of the safety system are themselves automatically activated when power from the battery 1 is applied causing the anti-collision lights 3 to be turn on, the transponder's GNSS receiver 4 to acquire locational information using its antenna and the transponder 5 to broadcast the aircraft's identity, position and altitude via it's dedicated antenna 6.

[0070] In the preferred embodiment, the GNSS receiver is a GPS receiver integrated into the transponder. Other GNSS that could be used include Europe's Galileo system or the Russian Federation's Global Orbiting Navigation Satellite System (GLONASS). When the operating altitude is reached the external air pressure decreases, the pressure detector opens the switch disconnecting the battery from the other components of the safety system. This turns off the safety system when the altitude exceeds the pre-set value.

[0071] Should a failure condition occur and the aircraft adopts its automated failure response it will, at some point, start to descend. When it descends to a level where the external air pressure is at or above the pressure for the pre-set altitude (e.g. when the aircraft descends into the normal operating altitude of civilian aircraft, which is between 30,000 and 42,000 feet) the switch closes completing the circuit and automatically turning on the anti-collision lights 3, the transponder & its GNSS receiver 4.

[0072] The design of the controller and the calibration of the spring in the pressure detector are all that are needed to allow the safety system to be turned on at the set altitude. Since the system is self-contained with no connection to any other aircraft system so it cannot be overridden from outside the safety system controller.

[0073] The second embodiment shown in FIG. 2 is a distributed safety system controller which consists of a core unit and a number of connectors. The core unit can be integrated into the internal structure of an unmanned high altitude aircraft.

[0074] In a comparable manner to the first embodiment the battery 1, pressure detector and switch 2 and a transponder 5 are contained within a housing 9, together they make up the core unit. The housing itself does not have any special aerodynamic qualities and can be constructed to fit the space within which it is to be positioned within the airframe as it merely acts as a container for the components within it.

[0075] Unlike the first embodiment the anti-collision lights 3, GNSS receiver & antenna 4 and transponder antenna 6 are integrated into other parts of the aircraft but are connected to the battery 1 and transponder 5 by connectors entering the housing though an aperture. Though these components are outside the housing 9 they are still powered from the battery 1 within the housing and control by the pressure detector & switch 2. This allows the anti-collision lights and antennas to be positioned optimally for the airframe.

[0076] In addition, a pressure detector tube is attached to the pressure detector & switch 2 and extends to a point on the exterior surface of the airframe to allow the external air pressure to be sensed.

[0077] The distributed safety system controller in FIG. 2 operates in the same way as described in the first embodiment.