Longitudinal motion control of air-breathing hypersonic vehicles based on time-varying models

The non-standard dynamic characteristics of air-breathing hypersonic flight vehicles together with the aerodynamic effects of hypersonic flight make the flight control of such systems highly challenging. Moreover the wide range of speed during operation and the lack of a broad flight dynamics database add significant plant parameter variations and uncertainties to the problem of controlling air-breathing hypersonic flight. In this paper, we present a general approach to this challenging problem based on linear time-varying plant models. This approach lets employment of some recent techniques developed for adaptive and non-adaptive control of systems with fast varying parameters via exploitation of a priori information about parameter variations. We discuss application of this approach to a generic analytical hypersonic flight vehicle model that is widely used in the literature as well as a detailed generic hypersonic vehicle concept model developed at the California State University - Los Angeles. The paper is concluded with some remarks on validations and extensions of the presented approach.