Scalar Reference Governor for Constrained Maneuver and Shape Control of Nonlinear Multibody Aircraft

Abstract

A control system for constrained control of a nonlinear multibody aircraft is described which exploits a combination of a scalar reference governor and a Linear Quadratic Integral (LQ-I) controller for maneuver load alleviation, trajectory control and shape control. A nonlinear multibody aircraft model for longitudinal flight is used to develop and validate the control system performance. The scalar reference governor is designed based on the linearized model and ensures that the imposed state and control constraints are satisfied. The mismatch between the linearized model used by the reference governor for prediction and the nonlinear dynamics of the multibody aircraft is accounted for in the reference governor design. The paper demonstrates the feasibility of the adopted control approach, including constraint enforcement, based on the nonlinear model simulations of pitching maneuvers.