Adaptive sliding mode control of a hypersonic flight vehicle

A Multi Input Multi Output (MIMO) adaptive sliding controller is designed and analyzed for the longitudinal dynamics of a generic hypersonic air vehicle, This vehicle model is highly nonlinear, multivariable, unstable and includes 6 uncertainty parameters. Simulation studies were conducted for trimmed cruise conditions of I 10,000 ft and Mach 15 where the responses of the vehicle to a step change in altitude and airspeed were evaluated. The commands were 100ft/s step-velocity and 2000ft step-altitude. The controller is evaluated for robustness with respect to parameter uncertainties using simulations. These simulation studies demonstrate that the proposed controller meets the performance requirements with relatively low amplitude control inputs despite parameter uncertainties.