Investigation of suitable flight test inputs for system identification of low frequency dynamics for the mini MUTT

Abstract

The purpose of this document is to investigate suitable excitations for flight test to identify rigid body dynamic characteristics. It is understood that the stiff wing mini MUTT (Fenrir) will be flown soon for identification of rigid body dynamic characteristic. The flight test data will further be used to identify unknown system parameters offline. The model system considered in this study is the BFF model at 40 kts as this is the lowest flight condition available and displays the least amount of coupling between rigid body and flexible dynamics. It is noted that this model still displays coupling between the pitch dynamics and the 1st symmetric wing bending mode. The objective is to focus on low frequency dynamics as it is expected that the stiff wing mini MUTT (Fenrir) should display similar low frequency dynamics. Different input sequences for the elevator and aileron control inputs, are investigated. The sensors investigated are the roll and pitch rates at the aircraft center body IMU.