Control Design for a Non-Minimum Phase Hypersonic Vehicle Model

Abstract

Air-breathing hypersonic vehicles are emerging as a method for cost-efficient access to space. Great strides have recently been made in the field of hypersonic vehicles, however the unique dynamics of the vehicles present challenges for control design. In this thesis, a nonlinear controller for a hypersonic vehicle model is designed using the Indirect Manifold Construction approach. The high fidelity hypersonic vehicle model considered in this thesis includes many of the challenging effects of hypersonic flight. The main challenge to control design is the vehicle's unstable internal dynamics. This non-minimum phase behavior prevents the use of many standard forms of nonlinear control techniques. The nonlinear controller developed in this thesis following the Indirect Manifold Construction approach uses a hierarchical control design to force outputs to commanded values while ensuring the internal dynamics of the system remain stable. The nonlinear controller is shown to be effective in simulation. The closed loop system is also shown to be stable through a Lyapunov based stability analysis.