Vehicle for, and a method of, detecting foreign object debris disposed on a runway or taxiway
A vehicle for detecting foreign object debris (FOD) disposed on a runway or taxiway, the vehicle comprising an array of forward-facing cameras configured to capture images of the runway or taxiway and transmit the images to FOD detection circuitry, each forwarding-facing camera being a camera oriented such that a respective dot product arising between the camera's optical axis and the forward direction is greater than zero, the array being arranged such that, when in use: a respective azimuthal angle arising between each forward-facing camera's optical axis and the forward direction does not exceed a limiting value, the azimuthal angle between an extremal forward-facing camera's optical axis and the forward direction being equal to the limiting value, and each forward-facing camera's imaging plane is positioned such that its displacement along the forward direction is at least a threshold distance away from its respective forward-facing camera.
1 . A vehicle for detecting foreign object debris (FOD) disposed on a surface of a runway or taxiway, the vehicle being configured to travel along the runway or taxiway in a forward direction and comprising an array of forward-facing cameras configured to capture images of the runway or taxiway and transmit the images to FOD detection circuitry, each forwarding-facing camera being a camera oriented such that a respective dot product arising between a camera's optical axis and the forward direction is greater than zero, the array being arranged such that, when in use:
a forward-facing cameras' fields of view combine to form a cumulative field of view which spans a width of a to-be-imaged part of the runway or taxiway,
a respective azimuthal angle arising between each forward-facing camera's optical axis and the forward direction does not exceed a limiting value, the azimuthal angle between an extremal forward-facing camera's optical axis and the forward direction being equal to the limiting value,
each forward-facing camera's imaging plane is positioned such that its displacement along the forward direction is at least a threshold distance away from its respective forward-facing camera, the threshold distance being determined based on the width of the to-be-imaged part of the runway or taxiway, and the limiting value,
the limiting value being determined based on an extremal forward-facing camera's exposure time, a length scale of the FOD to be detected by the extremal forward-facing camera, a maximum tolerable amount of captured motion blur, and a velocity of the vehicle.
2 . The vehicle according to claim 1 , wherein the limiting value is determined based on the extremal forward-facing camera's field of view.
3 . The vehicle according to claim 1 , wherein the threshold distance is determined based on the extremal forward-facing camera's field of view.
4 . The vehicle according to claim 1 , wherein the limiting value is determined based on an extremal forward-facing camera's aperture size, and an illuminance of the FOD to be detected by the extremal forward-facing camera, and wherein the limiting value is determined based on the illuminance of the runway or taxiway.
5 . The vehicle according to claim 1 , wherein the array is arranged such that, when in use, a respective height of each forward-facing camera's principal point from the runway or taxiway is substantially half of a height of the forward-facing camera's imaging plane.
6 . The vehicle according to claim 1 , wherein each forward-facing camera is mounted to the vehicle such that the forward-facing camera's orientation with respect to the vehicle is rigidly fixed.
7 . The vehicle according to claim 6 , comprising one or more damping pads disposed between the forward-facing cameras and the vehicle.
8 . The vehicle according to claim 1 , wherein each forward-facing camera is a high-speed camera, and wherein an exposure time of at least one of the high-speed cameras is configurable within a predefined range of exposure times, and wherein a minimum exposure time of each high-speed camera does not exceed 0.001 seconds.
9 . The vehicle according to claim 1 , wherein a frame rate of at least one of the forward-facing cameras is configurable within a predefined range of frame rates, and wherein the frame rate of the at least one forward-facing camera is configured such that, while the foreign object debris lies within the forward-facing camera's field of view, the forward-facing camera captures at least three consecutive image frames depicting the foreign object debris.
10 . The vehicle according to claim 1 , wherein the length scale of the foreign object debris to be detected by the extremal forward-facing camera is greater than or equal to one centimetre.
11 . The vehicle according to claim 1 , wherein the maximum tolerable amount of captured motion blur represents a ratio of a maximum allowable intra-frame displacement of the foreign object debris and an intra-frame length scale of the foreign object debris, and wherein the ratio does not exceed 0.2.
12 . The vehicle according to claim 1 , wherein the width of the to-be-imaged part of the runway or taxiway is greater than or equal to half of the width of the runway or taxiway.
13 . The vehicle according to claim 1 , wherein, when in use, the vehicle's velocity is greater than or equal to 40 kilometres per hour.
14 . The vehicle according to claim 1 , wherein the threshold distance is greater than or equal to 10 metres.
15 . The vehicle according to claim 1 , comprising:
a set of driving cameras configured to capture images for unmanned driving of the vehicle; and
one or more suspension systems coupled between the set of driving cameras and the vehicle.
16 . The vehicle according to claim 1 , wherein the vehicle is remotely operated or is autonomous.
17 . The vehicle according to claim 1 , comprising a set of forward-facing light emitting elements.
18 . The vehicle according to claim 1 , comprising the FOD detection circuitry.
19 . A method of detecting foreign object debris (FOD) disposed on a runway or taxiway, comprising the steps of:
obtaining a vehicle according to claim 1 ;
obtaining FOD detection circuitry;
controlling the vehicle to travel along the runway or taxiway in a first forward direction from a first location to a second location;
while the vehicle is travelling in the first forward direction, controlling each of the forward-facing cameras to capture images of the runway or taxiway and transmit the images to the FOD detection circuitry;
controlling the vehicle to travel along the runway or taxiway in a second forward direction from a third location to a fourth location, the second forward direction being substantially opposite the first forward direction; and
while the vehicle is travelling in the second forward direction, controlling each of the forward-facing cameras to capture images of the runway or taxiway and transmit the images to the FOD detection circuitry.
20 . The method according to claim 19 , wherein the vehicle's velocity is greater than or equal to 40 kilometres per hour when travelling from the first location to the second location and when travelling from the third location to the fourth location.