Nonlinear controller design for a highly coupled VSTOL aircraft

A nonlinear longitudinal multivariable controller has been designed for a vertical take-off and landing (VSTOL) aircraft model using the robust inverse dynamic estimation (RIDE) control theory to improve aircraft performance and reduce pilot workload throughout the jet to wing-borne transition phase. This paper discusses the design procedure of the RIDE controller for the speed envelope of hover to 200 knots throughout which the aircraft undergoes significant nonlinear changes in dynamics. Controller design issues such as the choice of feedback variables, the selection of pilot inceptor configurations and functionalities, and integrator anti-windup techniques in the presence of actuator saturation are discussed. The presentation of pilot-in-the-loop nonlinear simulation studies the performance of the controller