Robust Adaptive Multiple Model Controller Design for an Airbreathing Hypersonic Vehicle Model

between the aerodynamics, propulsion, and structures result in a challenging control model. Capturing these uncertainties as real and complex uncertainties motivates the use of mixed-µ synthesis techniques to generate a controller. However, because the uncertainties limit achievable performance, adaptation is needed to achieve precise trajectory tracking. A new multiple model adaptive control (MMAC) approach, adaptive mixing control (AMC), is applied to achieve superior velocity and altitude tracking. The AMC approach, by combining mixed-µ synthesis and adaptive control approaches, incorporates robust-stability and -performance objectives into the control design. Discontinuous switching between candidate controllers is avoided by mixing. Stability issues of mixing multiple stabilizing controllers is addressed using a mixing strategy based on the Youla parameterization of all stabilizing controllers. An AMC scheme and a nonadaptive robust scheme (i.e. mixed-µ compensator) are designed for the uncertain AHFV model at hypersonic cruise (Mach 10, 98,425 ft altitude). A comparison of the two approaches is conducted, and simulation results demonstrate the eectiveness of the AMC approach.