Robust μ-synthesis Loop Shaping for Altitude Flight Dynamics of a Flying-Wing Airframe

• Published in: Journal of intelligent & robotic systems 2015-08, Vol.79 (2), p.259-273
• Main Authors: Santoso, Fendy, Liu, Ming, Egan, Gregory K.
• Format: Article
• Language: English
• Subjects: Artificial Intelligence; Automatic pilots; Control; Dynamical systems; Dynamics; Electrical Engineering; Elevons; Engineering; Mechanical Engineering; Mechatronics; Partitioning; Robotics; Throttles; Uncertainty; Unmanned aerial vehicles
• ISSN: 0921-0296; 1573-0409
• DOI: 10.1007/s10846-014-0059-0

In this paper we present a centralised flight-by-wire system based on μ -synthesis approach to the longitudinal flight motion of our experimental flying wing unmanned aerial vehicle (UAV), P15035 series. The challenge associated with our UAV is related to the fact that all motions of our UAV are controlled by two independently-actuated-ailerons namely elevons, together with its throttle. The scope of this research, nonetheless, falls within the area of elevon control based on the trimmed linear longitudinal flight modes obtained experimentally while throttle was set constant. The reason for considering μ -synthesis autopilot is to minimise the effects of uncertainty in modelling by maximising the amount of tolerable uncertainty within our system’s bandwidth as we aim to minimise the structure singular value μ of the corresponding robust performance associated with the uncertain systems. Second, it also provides flexibility in tunning due to the absence of partitioning model of MIMO system. Hence the entire autopilot was designed by keeping the system model as a whole. We also perform a comparative study with respect to well-known H ∞ mixed sensitivity autopilot. Our study indicates that the μ synthesis autopilot designed possesses better performances both in time and frequency domain as indicated by reasonably quick settling time in the absence of overshoot while still maintaining better robust stability margin.