Patent ID: 6061612
Filing Date: 2000-05-09
Classification: G01C,G05D

Abstract:
A process for managing air speed in compliance with a time constraint of an aerodyne traveling a path in an unsettled meteorological environment, comprising:determining a point of the path, onwards of which it becomes materially impossible to comply with the time constraint requested by following a previously scheduled speed profile, and where it becomes necessary to alter said previously speed profile over a remaining portion of the path remaining to be traveled; anddetermining a new speed profile for the remaining portion of the path complying with the constraint, by dividing the remaining portion of the path in segments and determining segment-by-segment speed corrections starting from said point and up to a last modifiable segment, a speed variation in each of the segments being limited to a maximum value so as to avoid overly large variations in speed with respect to an optimal speed,wherein determining the new speed profile comprises determining a new speed over a given segment by:a) approximating a curve, giving the time of flight t as a function of speed V, with an equation with three coefficients c.sub.1, c.sub.2 and c.sub.3 :V=c.sub.1 /t+c.sub.2 /t.sup.2 +c.sub.3 /t.sup.3,b) determining the coefficients c.sub.1, c.sub.2 and c.sub.3, such that the curve passes through three points of support,c) calculating an approximate value Vapp.sub.1, of the new speed, satisfying the constrained time of flight tcstr, with:(Vapp.sub.1 =c.sub.1 /tcstr+c.sub.2 /tcstr.sup.2 +c.sub.3 /tcstr.sup.3),d) determining a new time of flight tapp.sub.1 by computing the path for the approximate value of the new speed,e) incorporating the approximate value of the new speed as the new speed if the new time of flight tapp.sub.1 determined is sufficiently close to the constrained time tcstr, andf) repeating b) through e), each time using the three points of support closest to the constrained time tcstr for as long as the new time of flight tapp.sub.1 determined is too far from the constrained time tcstr.