Imaging method and apparatus

• US 10,203,691 B2
• Filed: 12/04/2014
• Issued: 02/12/2019
• Est. Priority Date: 12/06/2013
• Status: Active Grant

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Tebay, Andrew Christopher
• Primary Examiner(s): Tissot, Adam D
• Assistant Examiner(s): Smith, Aaron C
• Application Number:
  US15/100,528
• Publication Number:
  US 20160306356A1
• Time in Patent Office: 1,531 Days
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 2101/30 for imaging, photography or videography
• CPC Class Codes: B64U 2101/31 for surveillance
• 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 50/30 Supply or distribution of electrical power
• CPC Class Codes: B64U 50/33 generated by combustion engines
• CPC Class Codes: G05D 1/0094 involving pointing a payload, e.g. camera, weapon, sensor, towards a fixed or moving target
• CPC Class Codes: G08G 5/003 Flight plan management
• CPC Class Codes: G08G 5/0069 specially adapted for an unmanned aircraft

Abstract

Disclosed is an imaging method for imaging terrain using a sensor on an unmanned aircraft. The method comprises: acquiring a range of motion of the sensor; acquiring positional information of the terrain; acquiring parameter values relating to aircraft maneuverability; using the acquired information, determining a procedure; performing, by the aircraft, the procedure and simultaneously capturing, by the sensor, a set of images of only parts of the terrain. The procedure comprises the aircraft moving with respect to the area of terrain and the sensor moving with respect to the aircraft such that each point in the area of terrain is coincident with a footprint of the sensor on the ground for at least some time. Also, every point in the area of terrain is present within at least one of the captured images.

Claims

1. An imaging method for imaging an area of terrain using a sensor mounted on an unmanned aircraft, the method comprising:

acquiring, by one or more processors, a specification of possible positions and orientations relative to the aircraft to which the sensor may be moved;

acquiring, by the one or more processors, positional information of the area of terrain;

acquiring, by the one or more processors, a specification of the manoeuvrability of the aircraft;

using the acquired specification of the possible positions and orientations of the sensor relative to the aircraft, the acquired positional information of the area of terrain, and the acquired specification of the manoeuvrability of the aircraft, determining, by the one or more processors, a first procedure and a second procedure;

performing, by the aircraft via one or more aircraft subsystems and the one or more processors, the first procedure, the first procedure comprising the aircraft moving with respect to the area of terrain along a first route and the sensor moving with respect to the aircraft such that, for each point in the area of terrain, each point is coincident with a footprint of the sensor on the ground for at least some time during the first procedure;

whilst the aircraft performs the first procedure, capturing, by the sensor, a first set of images, each image in the first set being of only part of the area of terrain, the first set of images being such that, for every point in the area of terrain, one of the points is present within at least one of the images in the first set;

processing the first set of images to detect, within at least one of the first images, a first target; and

acquiring, by the one or more processors, a position on the ground of the detected first target;

thereafter, performing, by the aircraft via said one or more aircraft subsystems and the one or more processors, the second procedure, the second procedure comprising the aircraft moving with respect to the area of terrain along a second route and the sensor moving with respect to the aircraft such that, for each point in the area of terrain, each point is coincident with a footprint of the sensor on the ground for at least some time during the second procedure, wherein the second procedure is determined using the position on the ground of the first target, such that a direction in which the aircraft flies when the first target is imaged during the second procedure is perpendicular to a direction in which the aircraft was flying during the first procedure when an image of the first target was captured; and

whilst the aircraft performs the second procedure, capturing, by the sensor, a second set of images, each image in the second set being of only part of the area of terrain, the second set of images being such that, for every point in the area of terrain, one of the points is present within at least one of the images in the second set.

2. A method according to claim 1, further comprising registering the first set of images with the second set of images.

3. A method according to claim 1, wherein determining the second procedure comprises minimising overlap between the first route and the second route.

4. A method according to claim 1, wherein the one or more processors are located on-board the aircraft.

5. A method according to claim 1, wherein

the method further comprises acquiring, by the one or more processors, a specification of a volume of airspace;

the step of determining the first procedure comprises, using the specification of the volume of airspace, determining the first procedure such that the aircraft remains with the volume of airspace during the first procedure.

6. A method according to claim 1, wherein the first procedure is determined such that the number of turns performed by the aircraft whilst performing the first procedure is minimised.

7. A method according to claim 1, the method further comprising:

processing the captured images to detect, within at least one image, a second target;

acquiring, by the one or more processors, a position on the ground of the detected second target;

using the acquired specification of possible positions and orientations relative to the aircraft to which the sensor may be moved, the acquired position of the second target, and the specification of the manoeuvrability of the aircraft, determining, by the one or more processors, a third procedure to be performed by the aircraft;

performing, by the aircraft via said one or more aircraft subsystems and the one or more processors, the third procedure; and

whilst the aircraft performs the third procedure, capturing, by the sensor, a third set of images;

wherein

the third procedure comprises the aircraft moving with respect to the second target and the sensor moving with respect to the aircraft such that the second target is coincident with a footprint of the sensor on the ground for the entire duration of the third procedure; and

capturing the third set of images is performed such that the whole of the second target is present within each image in the third set.

8. A method according to claim 1, the method further comprising:

processing the captured images to detect, within at least one image, a third target;

acquiring, by the one or more processors, a position on the ground of the detected third target;

acquiring, by the one or more processors, a specification of a direction relative to the aircraft in which an exhaust of the aircraft points; and

using the acquired position of the third target, the specification of the manoeuvrability of the aircraft, and the acquired specification of the direction, determining by the one or more processors, a third route for the aircraft; and

following, by the aircraft, the third route;

wherein

the determination of the third route comprises minimising a duration for which the exhaust of the aircraft is directed towards the third target.

9. A method according to claim 1, wherein

the aircraft comprises a payload releasably attached to an aircraft;

and

the method further comprises;

processing the captured images to detect, within at least one image, a fourth target;

acquiring, by the one or more processors, a position on the ground of the detected fourth target;

acquiring, by the one or more processors, parameter values relating to properties of the payload;

acquiring, by the one or more processors, parameter values relating to environmental conditions in which the aircraft is flying;

using the acquired position of the fourth target, the acquired parameter values relating to properties of the payload, and the acquired parameter values relating to environmental conditions, determining, by the one or more processors, a position and a velocity for the aircraft;

using the determined position and velocity for the aircraft, determining, by the one or more processors, a fourth procedure for the aircraft;

performing, by the aircraft via said one or more aircraft subsystems and the one or more processors, the fourth procedure; and

at a point in the fourth procedure that the aircraft has the determined position and velocity, releasing, by the aircraft, the payload;

the determined position and a velocity for the aircraft are such that, were the aircraft to release the payload whilst located at the determined position and travelling at the determined velocity, the payload would land on the ground within a predetermined distance of the fourth target; and

the fourth procedure is such that, were the aircraft to perform the fourth procedure, at at least one instance during the fourth procedure, the aircraft would be located at the determined position and travelling at the determined velocity.

10. A method according to claim 1, the step of capturing the set of images comprises, for each image:

acquiring, by one or more processors, a specification of a region on the ground to be imaged;

measuring, by a position sensor fixedly mounted to a rigid support structure, a position of the position sensor;

measuring, by an orientation sensor fixedly mounted to the rigid support structure, an orientation of the orientation sensor;

using the measured position and orientation and using the acquired region specification, determining a position and orientation for the sensor, the sensor being mounted to the rigid support structure;

controlling the aircraft and the orientation of the sensor on-board the aircraft such that the sensor has the determined position and orientation, thereby providing that a footprint of the sensor on the ground is coincident with the region on the ground to be imaged; and

when the sensor has the determined position and orientation, capturing, by the sensor, one or more images of the area of the ground within the sensor footprint;

wherein

the rigid support structure is releasably coupled to the aircraft of the aircraft.

11. Apparatus for imaging an area of terrain the apparatus comprising:

a sensor mounted on-board an aircraft;

one or more processors configured to;

acquire a specification of possible positions and orientations relative to the aircraft to which the sensor may be moved;

acquire positional information of the area of terrain;

acquire a specification of the manoeuvrability of the aircraft;

using the acquired specification of possible positions and orientations relative to the aircraft to which the sensor may be moved, the acquired positional information of the area of terrain and the acquired specification of the manoeuvrability of the aircraft, determine a first procedure and a second procedure; and

one or more aircraft subsystems and the one or more processors for controlling the aircraft to perform the first procedure and, thereafter, the second procedure;

wherein

the first procedure comprises the aircraft moving with respect to the area of terrain along a first route and the sensor moving with respect to the aircraft such that, for each point in the area of terrain, each point is coincident with a footprint of the sensor on the ground for at least some time during the first procedure;

the second procedure comprises the aircraft moving with respect to the area of terrain along a second route and the sensor moving with respect to the aircraft such that, for each point in the area of terrain that point is coincident with a footprint of the sensor on the ground for at least some time during the second procedure;

and

the sensor is configured to;

whilst the aircraft performs the first procedure, capture a first set of images, each image in the first set being of only part of the area of terrain, the first set of images being such that, for every point in the area of terrain, one of the points is present within at least one of the images in the first set;

process the first set of images to detect, within at least one of the first images, a first target;

acquire a position on the ground of the detected first target,

determine the second procedure by using the position on the ground of the first target, such that a direction in which the aircraft flies when the first target is imaged during the second procedure is perpendicular to a direction in which the aircraft was flying during the first procedure when an image of the first target was captured; and

whilst the aircraft performs the second procedure, capture a second set of images, each image in the first set being of only part of the area of terrain, the second set of images being such that, for every point in the area of terrain, that point is present within at least one of the images in the second set.

12. A non-transitory program or plurality of non-transitory programs such that when executed by a computer system or one or more processors mounted on an unmanned aircraft it/they cause the computer system or the one or more processors to:

acquire, by one or more processors, a specification of possible positions and orientations relative to the aircraft to which the sensor may be moved;

acquire, by the one or more processors, positional information of the area of terrain;

acquiring, by the one or more processors, a specification of the manoeuvrability of the aircraft

use the acquired specification of the possible positions and orientations of the sensor relative to the aircraft, the acquired positional information of the area of terrain, and the acquired specification of the manoeuvrability of the aircraft, determining, by the one or more processors, a first procedure and a second procedure;

perform, by the aircraft via one or more aircraft subsystems and the one or more processors, the first procedure, the first procedure comprising the aircraft moving with respect to the area of terrain along a first route and the sensor moving with respect to the aircraft such that, for each point in the area of terrain, each point is coincident with a footprint of the sensor on the ground for at least some time during the first procedure;

whilst the aircraft performs the first procedure, capture, by the sensor, a first set of images, each image in the first set being of only part of the area of terrain, the first set of images being such that, for every point in the area of terrain, one of the points is present within at least one of the images in the first set;

process the first set of images to detect, within at least one of the first images, a first target; and

acquire, by the one or more processors, a position on the ground of the detected first target;

thereafter, perform, by the aircraft via said one or more aircraft subsystems and the one or more processors, the second procedure, the second procedure comprising the aircraft moving with respect to the area of terrain along a second route and the sensor moving with respect to the aircraft such that, for each point in the area of terrain, each point is coincident with a footprint of the sensor on the ground for at least some time during the second procedure, wherein the second procedure is determined using the position on the ground of the first target, such that a direction in which the aircraft flies when the first target is imaged during the second procedure is perpendicular to a direction in which the aircraft was flying during the first procedure when an image of the first target was captured; and

whilst the aircraft performs the second procedure, capture, by the sensor, a second set of images, each image in the second set being of only part of the area of terrain, the second set of images being such that, for every point in the area of terrain, one of the points is present within at least one of the images in the second set.

13. The non-transitory program or plurality of non-transitory programs according to claim 12 wherein said non-transitory program or plurality of non-transitory programs are disposed on a non-transitory machine readable storage medium.