Observer-Based Optimal Control of a Quadplane with Active Wind Disturbance and Actuator Fault Rejection

Area of Science:

• Aerospace Engineering
• Control Systems
• Robotics

Background:

• Hybrid aircraft offer versatile capabilities for unmanned and urban air mobility.
• Ensuring safety and autonomy requires addressing control challenges like fault tolerance and wind disturbances.

Purpose of the Study:

• To develop an observer-based optimal control strategy for active fault and wind disturbance rejection in quadplane UAVs.
• To enhance trajectory tracking accuracy and system robustness under combined fault and wind conditions.

Main Methods:

• Linearization of the quadplane model for longitudinal, VTOL, and transition phases.
• Development of an unknown input observer for wind disturbance estimation using an auxiliary variable.
• Extension of the observer for simultaneous rejection of intermittent elevator faults and wind velocities.
• Mathematical proof of estimation error convergence.

Main Results:

• The observer-based approach significantly improves trajectory tracking accuracy compared to LQR and H-infinity controllers.
• The proposed observer outperforms alternative observers in disturbance and fault rejection.
• The method demonstrates efficient active rejection of actuator faults in windy conditions.

Conclusions:

• Observer-based optimal control provides a robust solution for hybrid aircraft control under disturbances and faults.
• The developed method enhances the safety and autonomy of unmanned aerial vehicles and urban air mobility platforms.