LPV Control Design for Over-actuated Hypersonic Vehicles Models

A typical control objective for a hypersonic vehicle model is to track a velocity and altitude reference while maintaining physical feasibility of the control input and the state. The control design presented in this work relies on a linear parameter varying (LPV) model of the longitudinal dynamics and exploits the presence of redundant actuation to enforce a desired feasible behavior in steady-state. A novel LPV regulator design methodology is developed, which explicitly addresses the case of over-actuated models (i.e., models with more inputs than performance outputs). This is a non-trivial extension of the analysis and design of output regulators for LTI systems. The LPV regulator separates the control problem into a steady-state controller and a stabilizing controller. The steady-state controller produces a non-unique approximate steady-state using receding horizon constrained optimization, while the stabilizer renders the steady-state attractive. The steady-state controller represents an approach to addressing over-actuated LPV systems, alternative to static or dynamic control allocation, or standard optimal control. The stabilizer design utilizes the LPV separation principle to decompose the problem into state feedback and LPV reduced order observer design. This control methodology is applied to a high-delity control-evaluation model in simulation and its merits and drawbacks are discussed.