Accession Number:

ADA305852

Title:

Full Envelope Control of Nonlinear Plants with Parameter Uncertainty by Fuzzy Controller Scheduling.

Descriptive Note:

Doctoral thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1995-09-01

Pagination or Media Count:

210.0

Abstract:

A full envelope controller synthesis technique is developed for multiple-input single-output MISO nonlinear systems with structured parameter uncertainty. The technique maximizes the controllers valid region of operation, while guaranteeing pre-specified transient performance. The resulting controller does not require on-line adaptation, estimation, prediction or model identification. Fuzzy Logic FL is used to smoothly schedule independently designed point controllers over the operational envelope and parameter space of the systems model. These point controllers are synthesized using techniques chosen by the designer, thus allowing an unprecedented amount of design freedom. By using established control theory for the point controllers, the resulting nonlinear dynamic controller is able to handle the dynamics of complex systems which can not otherwise be addressed by Fuzzy Logic Control. An analytical solution for parameters describing the membership functions allows the optimization to yield the location of point designs both quantifying the controllers coverage, and eliminating the need of extensive hand tuning of these parameters. The net result is a decrease in the number of point designs required. Geometric primitives used in the solution all have multi-dimensional interpretations convex hull, ellipsoid, VoronoiDelaunay diagrams which allow for scheduling on n-dimensions, including uncertainty due to nonlinearities and parameter variation. Since many multiple-input multiple-output MIMO controller design techniques are accomplished by solving several MISO problems, this work bridges the gap to full envelope control of MIMO nonlinear systems with parameter variation. AN

Subject Categories:

  • Computer Programming and Software
  • Cybernetics
  • Operations Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE