Patent ID: 8515636

Claim:
A method of controlling a system for automatically landing an aircraft using image signals, comprising: an altitude measurement step of a Flight Control Computer (FCC) of the aircraft receiving altitude information of the aircraft from an altimeter; a landing mark recognition step of a camera installed in the aircraft and oriented toward a front of the aircraft capturing a landing mark at a landing location and transmitting it to the FCC; a landing mark measurement step of the FCC measuring horizontal and vertical lengths of the landing mark captured by the camera; a flight information calculation step performed by the FCC of the aircraft, calculating an angle between the aircraft and a ground, a ground range between the aircraft and the landing location and an slant range between the aircraft and the landing location using the altitude information, the horizontal and vertical lengths of the landing mark measured at the landing mark measurement step, angle information composed of pitch, roll and yaw angles of the aircraft and an angle of entry to a landing runway; and a flight control step performed by the FCC of the aircraft, of controlling flight and attitude of the aircraft using the calculated flight information, wherein: the angle θ between the aircraft and the ground is calculated using Equation 1, the ground range GR between the aircraft and the landing location is calculated using Equation 2, and the slant range SR between the aircraft and the landing location is calculated using Equations 3 or 4: θ=tan −1 ( y ″ cos(δ)cos(α)/( x ′ cos(β))) (1) GR= h*x ′ cos(β)/( y ″ cos(δ)cos(α)) (2) SR= h /sin(tan −1 ( y ″ cos(δ)cos(α)/( x ′ cos(β)))) (3) SR=GR/cos(tan −1 ( y ″ cos(δ)cos(α)/( x ′ cos(β)))) (4) where α: the pitch angle, β: the roll angle, δ: the yaw angle, x: the horizontal length of the landing mark measured from the image information recognized by the camera, x′=x /cos(β), y: the vertical length of the landing mark measured from the image information recognized by the camera, y′=y /cos(α), y″=y ′/cos(δ), and h: the altitude information measured by the altimeter.