UNMANNED AIR VEHICLE (UAV), CONTROL SYSTEM AND METHOD

• US 20120199698A1
• Filed: 09/06/2011
• Published: 08/09/2012
• Est. Priority Date: 03/05/2009
• Status: Abandoned Application

• Current Assignee: Cranfield Aerospace Ltd.
• Original Assignee: Cranfield Aerospace Ltd.
• Inventors: THOMASSON, Peter Geoffrey, JONES, Robert Idris, POLL, David Ian Alistair
• Application Number:
  US13/226,179
• Publication Number:
  US 20120199698A1
• Time in Patent Office: Days
• US Class Current: 244/175
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/25 Fixed-wing aircraft VTOL aircraft B64U10/20
• CPC Class Codes: B64U 2101/30 for imaging, photography or videography
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: B64U 2201/20 Remote controls
• CPC Class Codes: B64U 50/13 using external fans or propellers
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: G05D 1/0094 involving pointing a payload, e.g. camera, weapon, sensor, towards a fixed or moving target
• CPC Class Codes: G05D 1/0825 using mathematical models

Abstract

A gust-insensitive unmanned air vehicle (UAV) for imaging the ground, comprising a substantially neutrally stable air frame having a fuselage and at least three wings which include control surfaces. The wings are arranged in symmetrical relation about the fuselage and confer the UAV with a roll stability about a longitudinal axis of the fuselage for any roll angle. The UAV also includes a propulsion device for propelling the UAV in flight, an image sensor for imaging the ground, and a flight control system for controlling the in-flight operation of the UAV. The flight control system includes flight control sensors and is operative to render the UAV gust insensitive in response to inputs from the flight control sensors.

Claims

1. A gust-insensitive unmanned air vehicle (UAV) for imaging the ground, the UAV comprising:

an airframe which is substantially neutrally stable and comprises a fuselage and at least three wings which include control surfaces, wherein the wings are arranged in symmetrical relation about the fuselage and confer the UAV with a roll stability about the longitudinal axis of the fuselage for any roll angle, thereby allowing the roll angle of the UAV to be set to any required angle independent of the heading and pitch angle of the UAV;

a propulsion device for propelling the UAV in flight;

an image sensor for imaging the ground, wherein the image sensor has a footprint, the position of which is determined by the roll angle of the UAV; and

a flight control system for controlling the in-flight operation of the UAV, wherein the flight control system includes flight control sensors and is operative to render the UAV gust insensitive in response to inputs from the flight control sensors, whereby the UAV exhibits substantially only linear displacements in response to wind gusts, and control the roll angle of the UAV to determine the position of the sensor footprint.

2. The UAV of claim 1, wherein the airframe comprises four wings which are arranged in cross (X) formation, wherein the wings are forwardly swept in the direction of flight of the UAV.

4. The UAV claim 1, wherein the propulsion device is operative to generate a propulsion air flow, which acts to propel the UAV in flight, and wherein the propulsion device is located forwardly of at least part of the wings in the direction of flight of the UAV, such that the propulsion air flow is directed over the control surfaces of the wings, and wherein the propulsion device comprises a propeller and a drive motor which drives the propeller, or a jet.

7. The UAV of claim 1, wherein the image sensor has a fixed position in relation to the airframe, and wherein the image sensor includes one or more sensor elements.

10. The UAV of claim 1, wherein the image sensor is movable only in a single axis in relation to the airframe.

12. The UAV of claim 1, wherein the flight control system comprises a motion sensor for sensing motion of the UAV, preferably the motion sensor provides orientation measurements, including pitch angle, roll angle and heading of the UAV, and inertial measurements, including acceleration and angular rate of the UAV.

13. The UAV of claim 1, wherein the flight control system comprises an air speed sensor for sensing the speed of the UAV.

14. The UAV of claim 1, wherein the flight control system comprises a position sensor for sensing the latitude, longitude and height of the UAV, preferably the position sensor comprises a GPS receiver.

15. The UAV of claim 1, wherein the flight control system comprises a proximity sensor for sensing proximity of physical structures, through or around which the UAV is to be navigated, and the flight control system is operative automatically to navigate the UAV utilizing control inputs from the proximity sensor, at a fixed height, and wherein the proximity sensor comprises one or more sensor units, one or more radar sensor units, one or more infra-red sensor units, one or more laser sensor units or one or more acoustic sensor units.

18. An unmanned air vehicle (UAV) control system for imaging the ground, the UAV control system comprising:

the UAV of claim 1, further comprising;

a communications module for communicating with a ground station; and

a ground station for controlling operation of the UAV, wherein the ground station comprises;

a communications module for communicating with the UAV; and

a ground control system for controlling operation of the UAV.

20. The UAV control system of claim 18, wherein the communications module of the UAV comprises a transmitter for transmitting video signals and telemetry data to the ground station and a receiver for receiving telemetry data from the ground station, and the communications module of the ground station comprises a transmitter for transmitting telemetry data to the UAV and a receiver for receiving video signals and telemetry data from the UAV, and wherein the transmitter of the communications module of the UAV includes an encoder which receives a video signal from the image sensor and telemetry data from the flight control sensors, and encodes the telemetry data into blanking lines of the video signal to provide a combined signal, and the receiver of the communications module of the ground station includes a decoder which separates the telemetry data from the combined signal, and separately provides the telemetry data and a video signal, and wherein the encoder comprises an encoder card which generates video timing signals and a data stream, and a mixer unit which receives the video timing signals and data stream, converts the same into video levels and mixes the same into the combined signal.

23. The UAV control system of claim 18, wherein the UAV is operable in a plurality of different flight modes, wherein the UAV is operable in an orbit mode, in which the UAV is held in an orbit about an object on the ground, such that the sensor footprint is maintained over the object, and wherein the UAV is operable in a waypoint mode, in which the UAV is navigated around a set of waypoints, such that the sensor footprint is maintained on an object, and wherein the UAV is operable in an over-fly mode, in which the UAV is repeatedly navigated to over-fly an object, such that the sensor footprint is, where possible, maintained on the object, and wherein the UAV is operable in a search mode, in which the UAV is navigated to maintain the sensor footprint along a given line of search.

28. The UAV control system of claim 18, wherein the ground control system includes a user interface, which allows a user to identify an object in the image displayed on a display, and determine the position thereof, including the latitude, longitude and height, wherein the ground control system is operative to determine the position, including height, of the identified object, without the use of digital terrain data, and wherein the ground control system, in determining the position of the identified object, fixes the position of the identified object from a plurality of different positions of the UAV based on a reference height, and determines the position of the identified object relative to the reference height for the UAV from the plurality of object fixes, and wherein the ground control system determines the position of the identified object from the intersection of imaginary lines, for each object fix, from the UAV to the object.

32. The UAV control system of claim 18, wherein the UAV further comprises:

a second, forward-looking image sensor for imaging air space ahead of the UAV in flight, wherein the second image sensor is movable in only a single axis, and wherein the ground control system is operable, through control of the roll angle of the UAV and movement of the second image sensor, to scan the air space ahead of the UAV.

3. (canceled)

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16. (canceled)

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24-27. -27. (canceled)

29-31. -31. (canceled)

33-53. -53. (canceled)

54. A gust-insensitive unmanned air vehicle (UAV) for imaging the ground, the UAV comprising:

an airframe which is neutrally stable and comprises a fuselage and wings which include control surfaces;

a propulsion device for propelling the UAV in flight;

an image sensor for imaging the ground, wherein the image sensor has a footprint, the position of which is determined by the orientation of the UAV; and

a flight control system for controlling the in-flight operation of the UAV, wherein the flight control system includes flight control sensors and is operative to render the UAV gust insensitive in response to inputs from the flight control sensors, whereby the UAV exhibits substantially only linear displacements in response to wind gusts.

55. The UAV of claim 54, wherein the airframe comprises four wings which are arranged in cross (X) formation, wherein the wings are forwardly swept in the direction of flight of the UAV.

56-70. -70. (canceled)

71. An unmanned air vehicle (UAV) control system for imaging the ground, the UAV control system comprising:

an unmanned air vehicle (UAV) including an image sensor for imaging the ground, the image sensor having a footprint, the position of which is determined by the orientation of the UAV, and a communications module for communicating with a ground station; and

a ground station for controlling operation of the UAV, the ground station comprising a communications module for communicating with the UAV, and a ground control system for controlling operation of the UAV.

73. The UAV control system of claim 71, wherein the communications module of the UAV comprises a transmitter for transmitting video signals and telemetry data to the ground station and a receiver for receiving telemetry data from the ground station, and the communications module of the ground station comprises a transmitter for transmitting telemetry data to the UAV and a receiver for receiving video signals and telemetry data from the UAV, and the transmitter of the communications module of the UAV includes an encoder which receives a video signal from the image sensor and telemetry data from flight control sensors, and encodes the telemetry data into blanking lines of the video signal to provide a combined signal, and the receiver of the communications module of the ground station includes a decoder which separates the telemetry data from the combined signal, and separately provides the telemetry data and a video signal.

75. The UAV control system of claim 73, wherein the encoder comprises an encoder card which generates video timing signals and a data stream, and a mixer unit which receives the video timing signals and data stream, converts the same into video levels and mixes the same into the combined signal.

72. (canceled)

74. (canceled)

76-96. -96. (canceled)

97. A method of operating an unmanned air vehicle (UAV), the method comprising the steps of:

providing an unmanned air vehicle (UAV), wherein the UAV has an airframe which is substantially neutrally stable and comprises a fuselage and at least three wings which include control surfaces, wherein the wings are arranged in symmetrical relation about the fuselage and confer the UAV with a roll stability about the longitudinal axis of the fuselage for any roll angle, thereby allowing the roll angle of the UAV to be set to any required angle independent of the heading and pitch angle of the UAV, and comprising a flight control system for controlling the in-flight operation of the UAV, wherein the flight control system includes flight control sensors and a proximity sensor for sensing proximity of physical structures, through or around which the UAV is to be navigated; and

automatically navigating the UAV utilizing control inputs from the flight control sensors and the proximity sensor, preferably at a fixed height, and rendering the UAV gust insensitive in response to inputs from the flight control sensors, whereby the UAV exhibits substantially only linear displacements in response to wind gusts.