A method for the 3D identification of the center of gravity of an aircraft

The aircraft weight and balance are a consequence of the own mass and the payload distribution, resulting in a position of the Centre of Gravity (CoG) that affect the behavior of the aircraft, its stability and the control effectiveness.The aircraft weight is normally measured statically using ground scales or sensors in the landing gear axles or struts, driving to 2D measurements of the CoG in longitudinal and lateral directions. Sometimes the 3D measurement is relevant because the aircraft architecture can involve weight shifts, i.e., the tiltrotor case.This paper studies the fast 3D measurement of the CoG in a tiltrotor type aircraft using photogrammetry and scales without previous levelling the aircraft. The system is modelled using multibody simulations to obtain data for the validation of the proposed methods. Finally, the expected uncertainty of the measurement is evaluated using Montecarlo method, analyzing the results statistically.