This paper addresses the issue of determining the most desirable “nominal closed-loop matrix” structure in linear state space systems, from stability robustness point of view, by combining the concepts of “quantitative robustness” and “qualitative robustness.” The qualitative robustness measure is based on the nature of interactions and interconnections of the system. The quantitative robustness is based on the nature of eigenvalue/eigenvector structure of the system. This type of analysis from both viewpoints sheds considerable insight on the desirable nominal system in engineering applications. Using these concepts, it is shown that three classes of quantitative matrices labeled “target sign stable (TSS) matrices,” “target pseudosymmetric (TPS) matrices,” and finally “quantitative ecological stable (QES) matrices” have features which qualify them as the most desirable nominal closed-loop system matrices. In this paper, we elaborate on the special features of these sets of matrices and justify why these classes of matrices are well suited to be the most desirable nominal closed-loop matrices in the linear state space framework. Establishment of this most desirable nominal closed-loop system matrix structure paves the way for designing controllers which qualify as robust controllers for linear systems with real parameter uncertainty. The proposed concepts are illustrated with many useful examples.
Determination of Most Desirable Nominal Closed-Loop State Space System Via Qualitative Ecological Principles
Contributed by the Dynamic Systems Division of ASME for publication in the JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL. Manuscript received December 22, 2014; final manuscript received October 27, 2015; published online December 4, 2015. Assoc. Editor: Srinivasa M. Salapaka.
Devarakonda, N., and Yedavalli, R. K. (December 4, 2015). "Determination of Most Desirable Nominal Closed-Loop State Space System Via Qualitative Ecological Principles." ASME. J. Dyn. Sys., Meas., Control. February 2016; 138(2): 021001. https://doi.org/10.1115/1.4031957
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