Multi-objective switching tracking control for a flexible air-breathing hypersonic vehicle

This article proposes a multi-objective switching tracking control scheme for the longitudinal motion of a flexible air-breathing hypersonic vehicle (FAHV). First, the linear parameter varying (LPV) model of the FAHV can be obtained by using Jacobian linearization approach. Second, for less conservative controller design purpose, the flight envelope is divided into smaller subregions, a family of mixed H₂/LQR controllers are designed, and each of them is suitable for a specific parameter subspace, the mixed H₂/LQR controllers are then switched in order to guarantee the closed-loop FAHV system to be asymptotically stable and satisfy specified performance indexes. The resulting multi-objective controller is found by solving a convex constraint problem which can be efficiently solved using available linear matrix inequality (LMI) techniques. In this method, we also take the gain variation of the controller into account due to parametric uncertainties of flight condition and the errors which existed in modeling. Finally, numerical simulations based on hypersonic vehicle nonlinear system have demonstrated the effectiveness of the proposed approach.