Patent ID: 8200421
Filing Date: 2012-06-12
Classification: G01C,G05D,G08G

Abstract:
1. A terrain avoidance method for an aircraft equipped with a collision alert device which monitors the flight of said aircraft with respect to the surrounding terrain and which is able to emit at least one alert, when said aircraft is at risk of colliding with the terrain while maintaining its current flight characteristics, according to which method a terrain avoidance maneuver is engaged when said collision alert device emits such an alert, the method comprising: (a) establishing an altitude profile representative of said terrain overflown by said aircraft on the basis of at least one database characteristic of said terrain; (b) measuring a plurality of parameters of said aircraft; (c) on the basis of at least some of said measured parameters, determining at least one altitude limit curve which belongs to a vertical plane passing through the longitudinal axis of said aircraft and which lies, at least partially, in front of said aircraft, wherein said limit curve comprises at least one intersection with said terrain altitude profile at least upon the engagement of said terrain avoidance maneuver, and wherein said at least one altitude limit curve consists of a series of segments comprising at least one horizontal segment, and said series of segments comprises an upward inclined segment, whose bottom end is connected to one of the ends of said horizontal segment and whose top end is oriented toward the sky; (d) determining the inclination of said upward inclined segment, during step (c), as a function of the current climb capability of said aircraft; (e) determining the length of said horizontal segment, during step (c), as a function of a terrain detection criterion which makes it possible to ensure that, when said avoidance maneuver is interrupted, said aircraft is at a minimum altitude allowing it to cross over the terrain situated in front of said aircraft; (f) monitoring said intersection of the limit curve with the altitude profile; (g) interrupting said terrain avoidance maneuver in the case where there is no intersection of said limit curve with said altitude profile; and carrying out steps (b), (c), (d), (e), (f) and (g) in a successive and repetitive manner until said avoidance maneuver is interrupted.