摘要

Fast response for turboshaft engine plays an important role in shaping sound helicopter maneuver ability during some typical violent maneuvers like autorotation power recovery. An engine NMPC (nonlinear model predictive control), integrated with flight predictive information, is proposed to obtains better engine response speed and reduces the rotor transient droop during autorotation power recovery. The on-board nonlinear predictive model consists of two parts: one is load" model - a main rotor torque model, the other is a turboshaft engine model. A suitable objective function is specified for the NMPC algorithm, being related to the deviation between the torque provided by the power turbine and that demanded by helicopter. The smaller torque deviation when its clutch being connected is, the less main rotor speed droop is. Finally, comparison simulations with a popular H-2/H-infinity robust control are demonstrated. It shows that by using the NMPC control law proposed here, the main rotor speed droop is only 0.36% with respect to reference speed, whereas it is 2.3% when using the robust control. Moreover, the designed control law is able to shorten the stable time a lot during the process, as the stable time is about 5 s when employing the new scheme, while it is about 20 s for the robust control.