Fault Tolerant Control Using .MU.-synthesis for the Elevon Fault of the Reusable Launch Vehicle

Abstract

Reusable launch vehicles (RLV) return to earth by gliding without thrust. In the return phase, one of the most likely and important faults to occur in the airframe is a jamming of an elevon. To tolerate this fault, the flight control system must maintain stability and performance during such a jam. Since this kind of fault can be modeled as a structured parameter deviation from a robust control point of view, this paper uses the μ-synthesis to present new methods to achieve a fault tolerant flight control system. ALFLEX (Automatic Landing FLight EXperiment), the automatic landing experimental vehicle being developed for RLV, is studied as an example. Some simulations are shown to verify the usefulness of the proposed method.