Accession Number:

ADA464794

Title:

Robust Stability Under Mixed Time Varying, Time Invariant and Parametric Uncertainty

Descriptive Note:

Technical rept.

Corporate Author:

CALIFORNIA INST OF TECH PASADENA CONTROL AND DYNAMICAL SYSTEMS

Personal Author(s):

Report Date:

1995-09-01

Pagination or Media Count:

35.0

Abstract:

Robustness analysis is considered for systems with structured uncertainty involving a combination of linear time-invariant and linear time-varying perturbations, and parametric uncertainty. A necessary and sufficient condition for robust stability in terms of the structured singular value p is obtained, based on a finite augmentation of the original problem. The augmentation corresponds to considering the system at a fixed number of frequencies. Sufficient conditions based on scaled small-gain are also considered and characterized. A substantial amount of research in recent years has been devoted to analysis and synthesis of control systems o achieve robust stability and performance in the presence of structured uncertainty. This implies a decentralized nature of the uncertain perturbation, which is a reasonable modeling choice for complex systems, where uncertainty may be introduced at the subsystem level see Safonov 17 and Doyle 5 for early treatments of this. In addition t o this spatial structure, different assumptions can be made on the dynamic properties of the uncertainty real parametric, linear time invariant LTI, linear time varying LTV or nonlinear perturbations. All these uncertainty classes arise naturally in modeling. Parametric uncertainty appears frequently in first principles models LTI perturbations are well suited when

Subject Categories:

  • Numerical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE