Enhanced eigenstructure assignment for aeroelastic control application

Abstract

A sophisticated robust controller design method for regulation of weakly damped aeroelastic structures using the primary flight controls (PFC) is presented. The approach is based on eigenvalue eigenvector assignment, and is capable of taking into account potentially competing objective specifications in either time or frequency domains, as well as parametric constraints. The infinite set of flight conditions and fuel load distributions lead us to represent the underlying aeroservoelastic plant as a linear multivariable multi-model system, for which a robust output feedback controller is sought in line with technical feasibility, parametric and dynamic uncertainty, architectural and sensor layout constraints. While the method of eigenvalue eigenvector assignment is well known in the fields of flight control design and modal decoupling, here the primary objective is to apply it to constrained simultaneous robust eigenvalue stabilisation. Since the intrinsic controller calculation is implemented as an multiobjective optimisation problem, aeroservoelastic performance specifications can be specified in the problem formulation. The suitability of the resulting low-order static output controller is demonstrated via real-time simulation of a real PFC hardware-in-the loop actuation system, both for normal and degraded configurations.