Development of a generic GUI-based software environment for aircraft trimming

Abstract

Clearance criteria of flight control laws are based on analysis of a complex nonlinear model of the aircraft type under consideration. Both nonlinear simulation of this model, as well as linearisation for subsequent analysis, require consistent definition and accurate computation of (quasi-) equilibrium conditions, also referred to as trimming. Well-known aircraft equilibrium conditions are straight and level flight, level turns, constant angle of attack, constant angle of side slip, etc. These conditions are characterised by specific sets of flight parameters and aircraft states. Unfortunately, each new aircraft model implementation requires manual marking of these parameters and states in the software, as well as manual programming of scripts to perform the actual trim computations. The objective of this Sub-Task is to automate these tasks. To this end, a Matlab-based graphical user interface (GUI) has been developed that allows easy definition of trimming conditions for new aircraft model implementations. Selections made in the GUI may be exported into trimming scripts for use in batch model analyses, as for example performed in the COFCLUO project.