摘要

An accurate and robust altitude controller is critical for vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAVs) in achieving quasi-stationary flight. Most UAV altitude control designs neglect the rotor dynamics. Therefore, they cannot be used for a tail-sitter UAV equipped with turbine engines because of the complicated engine dynamics with an apparent time delay. In this paper, we develop an integrated altitude controller that considers the engine dynamics. The new controller consists of a proportional-derivative (PD) control term and an acceleration feedback term. The stability region in the parameter space is analyzed and the controller is designed to achieve specific gain and phase margins. A UAV hover flight experiment is conducted and the results are presented to demonstrate the effectiveness of the proposed altitude controller.