Skip to main content
Log in

Root locations of an entire polytope of polynomials: It suffices to check the edges

  • Published:
Mathematics of Control, Signals and Systems Aims and scope Submit manuscript

Abstract

The presence of uncertain parameters in a state space or frequency domain description of a linear, time-invariant system manifests itself as variability in the coefficients of the characteristic polynomial. If the family of all such polynomials is polytopic in coefficient space, we show that the root locations of the entire family can be completely determined by examining only the roots of the polynomials contained in the exposed edges of the polytope. These procedures are computationally tractable, and this criterion improves upon the presently available stability tests for uncertain systems, being less conservative and explicitly determining all root locations. Equally important is the fact that the results are also applicable to discrete-time systems.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • [A1] J. Ackermann, Parameter space design of robust control systems,IEEE Trans. Automat. Control,25 (1980), 1058–1072.

    Article  Google Scholar 

  • J. Ackermann, Design of robust controllers by multi-model methods,Proceedings of the Seventh International Symposium on Mathematical Theory of Networks and Systems, Stockholm, 1985.

  • [B1] B. R. Barmish, Invariance of the strict Hurwitz property for polynomials with perturbed coefficients,IEEE Trans. Automat. Control,29 (1984), 935–936.

    Article  MathSciNet  Google Scholar 

  • [BG] S. Bialas and J. Garloff, Convex combinations of stable polynomials,J. Franklin Inst.,319 (1985), 373–377.

    Article  MathSciNet  Google Scholar 

  • [B2] N. K. Bose, A system-theoretic approach to stability of sets of polynomials,Contemp. Math.,47 (1985), 25–34.

    Google Scholar 

  • [C] P. L. Chebyshev,Complete Collected Works, Vol. 3. pp. 307–362, Izd. AN SSSR, Moscow, 1948.

    Google Scholar 

  • [FM] A. T. Fam and J. S. Meditch, A canonical parameter space for linear system design,IEEE Trans. Automat. Control,23 (1978), 454–458.

    Article  MathSciNet  Google Scholar 

  • [G1] F. R. Gantmacher,The Theory of Matrices, Chelsea, New York, 1960.

    Google Scholar 

  • [G2] B. K. Ghosh, Some new results on the simultaneous stabilizability of a family of single input, single output systems,Systems Control Lett.,6 (1985), 39–45.

    Article  MathSciNet  Google Scholar 

  • [HB] C. V. Hollot and A. C. Bartlett, Some discrete-time counterparts to Kharitonov's stability criterion for uncertain systems,IEEE Trans. Automat. Control,31 (1986), 355–356.

    Article  Google Scholar 

  • [HHB] L. Huang, C. V. Hollot, and A. C. Bartlett, Stability of families of polynomials: considerations in coefficient space,Internat. J. Control,45 (1987), 649–660.

    MathSciNet  Google Scholar 

  • [K] V. L. Kharitonov, Asymptotic stability of an equilibrium position of a family of systems of linear differential equations,Differentsial'nye Uravneniya,14 (1978), 2086–2088.

    MathSciNet  Google Scholar 

  • [M] A. A. Markov,Collected Works, pp. 78–105, Nauka, Moscow, 1948.

    Google Scholar 

  • [N] Y. I. Naimark,Stability of Linearized Systems, Leningrad Aeronautical Engineering Academy, Leningrad, 1949.

    Google Scholar 

  • [R] R. T. Rockafellar,Convex Analysis, Princeton University Press, Princeton, 1972.

    Google Scholar 

  • [S] D. D. Siljak,Nonlinear Systems, The Parameter Analysis and Design, Wiley, New York, 1969.

    MATH  Google Scholar 

  • [SBD] C. B. Soh, C. S. Berger, and K. P. Dabke, On the stability of polynomials with perturbed coefficients,IEEE Trans. Automat. Control,30 (1985), 1033–1036.

    Article  MathSciNet  Google Scholar 

  • K. H. Wei and B. R. Barmish, On making a polynomial Hurwitz invariant by choice of feedback gains,Proceedings of the 24th IEEE Conference on Decision and Control, Fort Lauderdale, FL, 1985.

Download references

Author information

Authors and Affiliations

Authors

Additional information

A. C. Bartlett was with the Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York. 12180, U.S.A. He is now with the Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, Massachusetts 01003, U.S.A.

The work of this author was supported by the National Science Foundation under Grant No. ECS-8609790.

The work of this author was supported by the Chinese Academy of Sciences and the State Education Commission of China.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bartlett, A.C., Hollot, C.V. & Lin, H. Root locations of an entire polytope of polynomials: It suffices to check the edges. Math. Control Signal Systems 1, 61–71 (1988). https://doi.org/10.1007/BF02551236

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02551236

Key words

Navigation