This paper aims to investigate theoretically and experimentally the dynamic behaviors of the pitch and roll motions of a small-scale unmanned air vehicle in loitering flight. Two fourth-order ARX (AutoRegressive with eXogenous input) models are successfully identified, and the performance analysis is carried out based on the flight test data. The validity of the identified model is verified by both time domain model prediction and frequency domain spectral analysis. With the proposed ARX models, two compensators are further designed using a frequency technique to improve the transient performance of the pitch and roll control channels. Simulations and experiments demonstrate that the proposed ARX model-based compensation control design strategy can improve the flight performance.

This paper presents the development of an electrically powered micro air vehicle (MAV) with a wingspan of 360 mm. A miniature flight control system including a self-made micro video image system especially suitable for MAV is developed. The aerodynamic performance of several airfoil sections at low chords Reynolds number is analyzed in order to find an optimum airfoil section for the MAV prototype. A small-sized propulsion testing setup is built to measure the performance of the motor-gear-propeller-battery combination so that an efficient propulsion system can be obtained. The TH360 MAV with a payload of a self-made micro color video image system has been successfully tested in the real-time flight, where the real-time images of the ground target can be transmitted from the onboard video camera to the ground.