US 5,716,032 AGranted

Unmanned aerial vehicle automatic landing system

AssigneeThe United States of America as represented by the Secretary of the Army

InventorPat H. McIngvale

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Abstract

An automatic landing system for guiding an unmanned aerial vehicle along a predetermined path to a predetermined point on the ground. The system includes an image processing means resident in the motion compensation processor that computes aerial vehicle parameters. The computed parameters are altitude, changes in altitude, changes in pitch and yaw angles, roll angle and changes thereto, and changes in cross range and down range position. These computations are based on the movement of elements in the video of an imaging sensor onboard the aerial vehicle. The motion compensation processor also measures the distance (in pixels or picture elements) between two beacons placed a known distance apart on either side of the apparent touchdown point. A recovery control processor uses these parameters to compute both desired and actual altitude as a function of range from the vehicle to the apparent point of touchdown and to provide offset error in azimuth from the desired flight path to the landing area. The recovery control processor also computes commands for the automatic pilot on the unmanned aerial vehicle which corrects the aerial vehicle's flight path. The recovery control processor will normally be located with the motion compensation processor, either on the ground or on the aerial vehicle. The video image can either be brought to the ground over a data link or the image processing can be performed onboard the aerial vehicle.

Claims5

Dependent claims

A landing system for directing a remotely piloted aerial vehicle to a predetermined point in a landing zone comprising:

an autopilot for controlling the flight path of a remotely piloted aerial vehicle;
a data terminal coupled to said autopilot for receiving and sending signals both to and from said autopilot, beacons disposed on the ground adjacent said predetermined point in said landing zone, said beacons consisting of first and second beacons, said first and second beacons being spaced a predetermined distance apart in a plane substantially normal to the plane of the line of sight path from an aerial vehicle imaging sensor when said vehicle is on a desired glide path, said first and second beacons and said predetermined point in the landing zone lying on a common line within said plane, and said first and second beacons generating signals aimed in the direction of said vehicle said imaging sensor being disposed in said aerial vehicle and aligned with the longitudinal axis of said vehicle for generating an image of the landing zone which contains said first and second beacons, said sensor receiving said signals generated by the first and second beacons and including the signals in said image of the landing zone;
a ground based motion compensation processor for calculating actual vehicle flight parameters and for generating output signals corresponding to said calculated parameters;
and a ground based recovery control processor coupled to receive said output signals generated by said motion compensation processor and for comparing said output signals corresponding to the calculated parameters to predetermined flight parameters necessary to land said vehicle at said predetermined point;
and said recovery control processor generating correction output signals for transmission to said autopilot data terminal for adjusting the actual vehicle flight parameters to bring said vehicle to a landing within said landing zone.

2 more elements

A landing system for directing a remotely piloted aerial vehicle to a predetermined point in a landing zone, comprising:

an autopilot for controlling the flight path of a remotely piloted aerial vehicle;
a data terminal coupled to said autopilot for receiving and sending signals both to and from said autopilot;
beacons disposed on the ground adjacent said predetermined point in said landing zone, said beacons consisting of first and second beacons defining a line therebetween, wherein said predetermined point is centered between said beacons on said line, said beacons being spaced a predetermined distance apart in a plane substantially normal to the plane of the line of sight path from an aerial vehicle imaging sensor when said vehicle is on a desired glide path, and said beacons generating signals aimed in the direction of said vehicle;
said imaging sensor being disposed in said aerial vehicle and aligned with the longitudinal axis of said vehicle for generating an image of the landing zone which contains said beacons, said sensor receiving said beacon generated signals and including the signals in said image of the landing zone;
a motion compensation processor for calculating actual vehicle flight parameters, and for generating output signals corresponding to said calculated parameters;
said motion compensation processor taking sequential video images from the imaging sensor, evaluating the movement of individual pixels, and calculating the overall movement of the imaging sensor during the elapsed time between the sequential video images;
and
a recovery control processor coupled to receive said output signals generated by said motion compensation processor and for comparing said output signals corresponding to the calculated parameters to predetermined flight parameters necessary to land said vehicle at said predetermined point;
and said recovery control processor generating correction output signals for coupling to said autopilot for adjusting the actual vehicle flight parameters to bring said vehicle to a landing within said landing zone, and wherein said auto adjusts the actual vehicle flight parameters to bring said vehicle to a landing by reducing engine speed to an idle and by stalling the vehicle by raising the nose to an attitude whereby the vehicle altitude begins to decrease independently of any control movement by the autopilot.

6 more elements

Dependencies are inferred from the claim text.