New methods for aerospace control system design using linear-adaptive and subspace-stabilization techniques.

摘要

In this dissertation the techniques of Linear-Adaptive and Subspace-Stabilization Control are used to develop new approaches to, and solutions 4 some important aerospace control problems. In the study of aircraft flight mechanics, one learns that the controlling of an aircraft's flight trajectory is achieved by strategically positioning the aircraft's attitude relative to the airflow, thereby producing the required aerodynamic forces. The associated Inversion-Problem is concerned with real-time calculation of the attitude rate profiles that must be followed in order to achieve a prescribed flight trajectory. In this dissertation the Linear-Adaptive Control technique is used to develop an elegant, simple and robust solution to the inversion problem. Moreover, the technique of Subspace-Stabilization is used to develop an effective control-law for actuating the control surfaces to achieve the required attitude rate profiles as calculated by the inversion-procedure. A reusable Launch Vehicle (RLV) model is used to demonstrate application of the results.; The generic flight control problem is a naturally layered problem, and me of the factors limiting flight performance is the phenomenon of incidence-lag which is characterized by a first-order dynamic response of an aircraft's trajectory to attitude changes. In this dissertation, the technique of Subspace-Stabilization is used to develop a novel dual-control strategy whereby “smart” coordinated actuation of redundant control surfaces, such as canards and elevons, is used to control an aircraft's attitude and normal motions to effectively circumvent the effects of incidence-lag.