Suggested Citation:
Sarigul-Klijn, Nesrin and Jonathan Huber (2006) In-Flight Reconfigurable Autopilot for Unmanned Aircraft: Hardware Development and Flight Test Results. Proceedings of the AIAA Atmospheric Flight Mechanics Conference and Exhibit

An in-flight reconfigurable autopilot control system test bed is designed, developed and tested. The need for such a test bed arises in control system research and development to verify performance and operability of the design. The test vehicle model, electronic hardware, and basic control algorithms are developed. The test vehicle is a 1/10th scaled Decathlon fixed-wing airplane. The airplane is chosen based on parts availability, ease of component replacement, available cargo space and its empty weight fraction that is representative of a full scale UAV. A mathematical model of the airplane is first developed for the design of flight control systems and for computer simulation. Longitudinal and lateral equations of motion are obtained to capture the motion associated with the vehicle. The numerical values are found using specialized computer programs developed for such tasks. Both Linear Quadratic Regular and Multi-Loop controllers are designed and compared for longitudinal and lateral control of the airplane. The hardware required to fly the test vehicle includes sensors, a microprocessor, and various support circuits. The hardware and support circuits are designed to measure angular rates, linear accelerations, pressure differences, and relative altitude. The measurements are gathered, analyzed, and acted upon by the processor to fulfill the requirements of the control algorithm. Finally, the longitudinal motion control system is tested in an in-house test bed. A hardware testing mechanism is provided to confirm algorithm simulation in a realistic scaled environment.