05.1 - Flight Dynamics and Control (Control & Modelling)
FLIGHT CONTROL LAW CLEARANCE USING WORST-CASE INPUTS
J. Diepolder¹, J.Z. Ben-Asher, Faculty of Aerospace Engineering - Technion, Israel; A. Gabrys¹, S. Schatz¹, M. Bittner¹, M. Rieck¹, B. Grüter¹, F. Holzapfel¹; ¹Institute of Flight System Dynamics - TUM, Germany
This study explores the effectiveness of applying optimal control techniques to the flight control law clearance problem, which is the challenge of ensuring the safety of an aircraft’s flight control system for all allowable inputs. The specific criteria chosen were the angle-of-attack limit exceeding criterion in the longitudinal plane, and the angle-of-sideslip limit exceeding criterion in the lateral plane. Using a general double-engine airplane aero data to obtain realistic aerodynamic coefficients, longitudinal and lateral linear models were developed. The flight control system developed by the Institute of Flight System Dynamics of TUM for this aircraft was used for the clearance task. The input signals in this study were pilot commands (stick and pedal) and/or wind disturbances in the form of gusts. It is shown that limited elevator/rudder/aileron deflection and rate of elevator/rudder/aileron can lead to extreme worst case performance.