Modeling and control for longitudinal attitude of a twin-rotor tail-sitter unmanned aerial vehicle

In this paper, the modeling and model reference adaptive control (MRAC) for longitudinal attitude of a twin-rotor tail-sitter unmanned aerial vehicle (UAV), which is highly unstable during flight, are presented. First, the attitude dynamic models are established. Linearized model for longitudinal attitude in vertical flight mode is given that is used in later derivation of controller as well as for testing the algorithms in simulation. Then, a control law based on the MRAC technique is utilized to stabilize the longitudinal attitude control system with uncertainty. Simulation results show that the MRAC of pitch angle has good trajectory tracking and the designed control law has strong adaptive ability and anti-jamming ability.