Lifting Body Flight Controller Design Using Gain Scheduled Classical Control

The application of gain scheduled classical control to the design of a flight controller for atmospheric reentry is discussed. Gain scheduling is used for large flight envelope of reentry glide of lifting body vehicle. The reentry vehicle is unpowered, and aerodynamic control surfaces modify the vehicle flight path angle based on the lateral acceleration com-mands from guidance. The control design is divided into two phases: linearizing of nonlinear vehicle model with altitude, adaptive gain scheduling as a function of dynamic pressure and aerodynamic parameters. The correctness and performance of the controller, during skip and glide phases, are evaluated in pitch plane with actuator and sensor dynamics. The controller efficiency, is validated in high-fidelity nonlinear six-degree-of-freedom dynamic model with guidance and navigation. Ro-bustness is evaluated with numerical simulations considering the uncertainties in the aerodynamics, mass, and reentry initial conditions.