Active Disturbance Rejection Control for Pitch Angle of UAVs

To deal with the complicated nonlinear flight system of an unmanned aerial vehicle (UAV) and various random disturbances and uncertain error presented during the flying, we develop an active-disturbance-rejection control (ADRC) law to achieve high performance control for pitch angle of longitudinal attitude, the controller includes three modules: a tracking-differentiator (TD), an extended state observer (ESO) and a nonlinear state error feedback law (NLSEF). Compared with fuzzy control by simulation, the results validate that the ADRC strategy is more advantageous in disturbance rejection, with faster response speed, higher control accuracy, stronger robustness, easier law and so on. Therefore, for an unmanned aerial vehicle, the proposed ADRC control law is suitable for the longitudinal attitude control of unmanned flight.