Fuzzy guidance of the shuttle orbiter during atmospheric reentry

The guidance law for the Space Shuttle Orbiter is required to track a refer ence state trajectory satisfying a given drag-acceleration versus velocity profile. Newly available nonlinear guidance laws will require complicated m ulti-dimensional interpolation. In this paper, Sugeno approximators (hybrid fuzzy-crisp inference systems) trained by example are used to conduct this interpolation. Moreover, the concept of surface-tracking guidance is intro duced in which the reference trajectory itself is updated when severe distu rbances warrants it. Surface tracking requires an "on-line optimizer" which is implemented using a constellation of a few blocks, two of which are mul ti-input/multi-output Sugeno approximators. The different approximators and guidance laws have been studied and simulated. (C) 1999 Elsevier Science L td. All rights reserved.