A Study on Longitudinal Attitude Control of Tilt Rotor Aircraft against Gyro Effect by Tilting Rotor Nacelles

In this study a synthesis of longitudinal attitude control system when Tilt Rotor Aircraft makes the rotor nacelles tilt at the translation from helicopter mode to airplane mode is proposed. First in order to keep the stable pitch motion, pitch rate feedback is used as a stability augmentation method. There the control surface is the small forward angle variation of thrust vectors of both rotors. Next in order to eliminate the counter moment around the center of gravity generated by tilting the rotor nacelles, that is Gyro Effect, and to keep the constant pitch angle P control is used as a controllability augmentation method. There control surface is the elevator angle.