A generalized mixed-sensitivity convex approach to hierarchical multivariable inner-outer loop control design subject to simultaneous input and output loop breaking specifications

Karan Puttannaiah, Armando Rodriguez, Kaustav Mondal, Justin A. Echols, Daniel G. Cartagena

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations

Abstract

In this paper, we present a generalized mixed-sensitivity multivariable framework for designing hierarchical inner-outer loop control systems for linear time invariant (LTI) plants subject to simultaneous input and output convex specifications. The methodology presented can handle a broad class of closed loop (e.g. H∞, H2, frequency- and time-domain) objectives. This is accomplished by exploiting the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization, the resulting convexification, and state-of-the-art polynomial-time convex solvers that can be applied to smooth and non-differentiable problems. It is well known that ill-conditioned plants (with large relative gain array entries (RGA)) can be particularly troublesome when specifications must be met at multiple loop breaking points (e.g. inputs/controls, outputs/errors). The associated tradeoffs can be quite severe for such systems. A hierarchical control architecture can exploit the additional feedback information in order to significantly help in making reasonable tradeoffs between properties at these loop-breaking points. The utility of the framework is illustrated by designing a control system for the longitudinal dynamics of a 3-DOF scramjet-powered hypersonic vehicle model - one that is unstable, non-minimum phase and flexible. For such a challenging vehicle, the method is shown to generate very good designs - designs that would be difficult to obtain without the new framework presented. Comparisons to other methods are made to further illustrate its power and transparency. While the focus of the paper is on finite-dimensional LTI multivariable plants and frequency domain specifications, the methods presented can also be applied to infinite-dimensional plants subject to time-domain specifications. In short, the paper provides a systematic approach to a large class of important control design problems.

Original languageEnglish (US)
Title of host publication2016 American Control Conference, ACC 2016
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages5632-5637
Number of pages6
Volume2016-July
ISBN (Electronic)9781467386821
DOIs
StatePublished - Jul 28 2016
Event2016 American Control Conference, ACC 2016 - Boston, United States
Duration: Jul 6 2016Jul 8 2016

Other

Other2016 American Control Conference, ACC 2016
CountryUnited States
CityBoston
Period7/6/167/8/16

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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    Puttannaiah, K., Rodriguez, A., Mondal, K., Echols, J. A., & Cartagena, D. G. (2016). A generalized mixed-sensitivity convex approach to hierarchical multivariable inner-outer loop control design subject to simultaneous input and output loop breaking specifications. In 2016 American Control Conference, ACC 2016 (Vol. 2016-July, pp. 5632-5637). [7526553] Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ACC.2016.7526553