Patent ID: 8165729

Claim:
A method for estimating forces exerted on at least one aircraft control surface comprising the successive steps of: a) generating current aircraft flight data; b) determining, from the generated aircraft flight data, a value Bl based on current deflection data and geometrical characteristics of a lever arm actuator of the at least one aircraft control surface; c) calculating, by a processor, from the determined value Bl based on the current deflection data and the geometrical characteristics, at least one hinge moment, wherein the at least one hinge moment is selected from the following hinge moments; c1) an aerodynamic hinge moment M 1 which depends on current values of dynamic pressure, local incidence of the at least one aircraft control surface, and deflection of said at least one aircraft control surface; c2) a hinge moment M 2 generated by mass of the at least one aircraft control surface, which based on the current depends on a current value of load factor; and c3) an internal hinge moment M 3 ; d) summing each hinge moment calculated in step c); and e) dividing the sum obtained in step d) by the value Bl determined in step b) to obtain an estimate of the forces exerted on said at least one aircraft control surface, wherein in step b), said value Bl is determined according to the following expression: Bl=R . sin(α cos [( R−L . cos( BO+δx ))/√{square root over ( L 2 +R 2 −2 .L.R . cos( BO+δx ))}]) in which: δx is a value of the current deflection data of the at least one aircraft control surface; R represents distance between a hinge line and a point of attachment of a rod of the lever arm actuator to the at least one aircraft control surface; L represents distance between a point of attachment of the lever arm actuator to a structure of the aircraft and said hinge line; and BO represents an angle between segments defining the distances R and L, when the at least one aircraft control surface is not deflected.