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) : Kobylarz, Thomas J.

PDF Url : ADA305852

Report Date : SEP 1995

Pagination or Media Count : 210

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 controller's 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 system's 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 controller's 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, Voronoi/Delaunay 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)

Descriptors :   *NONLINEAR SYSTEMS, *CONTROL THEORY, *STRUCTURED PROGRAMMING, DATA BASES, COMPUTER PROGRAM DOCUMENTATION, MATHEMATICAL MODELS, ALGORITHMS, COMPUTERIZED SIMULATION, UNCERTAINTY, OPTIMIZATION, ADAPTIVE CONTROL SYSTEMS, FLIGHT CONTROL SYSTEMS, COMPUTER AIDED DESIGN, TIME DEPENDENCE, PARAMETERS, MULTIVARIATE ANALYSIS, MATHEMATICAL LOGIC, THESES, INPUT OUTPUT PROCESSING, PARALLEL PROCESSING, SCHEDULING, APPROXIMATION(MATHEMATICS), FEEDBACK, POLYNOMIALS, HEURISTIC METHODS, FUZZY SETS, SYSTEMS ANALYSIS, NONLINEAR ANALYSIS, SUBROUTINES, DESIGN CRITERIA, DYNAMIC PROGRAMMING, AIRCRAFT MODELS, NONLINEAR PROGRAMMING, CONVEX SETS, AIRCRAFT DESIGN.

Subject Categories : Computer Programming and Software
      Cybernetics
      Operations Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE