This paper presents a method to estimate attitudes for the rolling and
pitching attitude control of an unmanned helicopter in the hovering flight
mode. The required observations for the proposed method are offered by
only one single antenna Global Positioning System (GPS) receiver and
three-axis rate gyroscopes. The attitude of the helicopter was estimated
using GPS velocity measurements and then complemented with integrated
attitudes of gyros’ angular rates. This velocity-based attitude is called
pseudo attitude (PA). The estimation results of PA were compared with true
attitudes given by an attitude and heading reference system (AHRS).
Furthermore, flight experiments were conducted to gather necessary data for analyzing the feasibility of autonomous hovering by fuzzy logic control (FLC) using the PA method. The FLC generating output followed the pilot’sreal-time control signal for hovering flight and the usability of the FLC was verified. Finally, the complemented PA was demonstrated to be capable of being utilized to control for rolling and pitching in hovering.