Dynamic Tailstrike Avoidance Controller for Takeoff and Landing
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Systems, control and mechatronics (MPSYS), MSc
Publicerad
2023
Författare
Ahlström, Jonathan
Ingemarsson, Gabriel
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Abstract
In this thesis a dynamic controller has been designed for the use of preventing tailstrikes during takeoff and landing. A linear quadratic regulator has been used due to the ease of incorporating reference commands with state control, allowing the controller to be designed for tailstrike prevention without overridering the pilot completely. Different tuning configurations have been explored and evaluated on
their response times, tailstrike preventive abilities, wind turbulence mitigation and pilot handling qualities. A single state feedback gain shows promising robustness results and tailstrike preventive abilities but has difficulties fulfilling conflicting handling quality objectives with a single tuning. Gain scheduling allows for a responsive aircraft at low risk for tailstrikes while mitigating excessive pitch attitudes at a high
risk for tailstrike. The controller is able to reduce the risk of tailstrikes at takeoff with aggressive tunings, but because of modeling difficulties on ground level a takeoff could not be performed reliably in flight simulator testing. For a full verification of the controller the model needs to be improved for ground level and able to trim for zero velocity. The scheduled gain controller is able to prevent tailstrikes for landing
but requires a larger scope of gains at low and high airspeeds to avoid a conservative tuning schedule. Further robustness analysis and flight testing is required to guarantee the safety of the function.