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Robust modular control system design using an inner‐loop reference model and μ synthesis techniques
Author(s) -
Vermillion Chris,
Sun Jing,
Butts Ken
Publication year - 2013
Publication title -
international journal of robust and nonlinear control
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.361
H-Index - 106
eISSN - 1099-1239
pISSN - 1049-8923
DOI - 10.1002/rnc.2822
Subject(s) - modular design , inner loop , control theory (sociology) , compensation (psychology) , loop (graph theory) , loop fission , computer science , control engineering , process (computing) , feedback loop , control (management) , controller (irrigation) , engineering , mathematics , artificial intelligence , psychology , computer security , combinatorics , psychoanalysis , compiler , agronomy , biology , programming language , operating system
SUMMARY For complex dynamic systems, a modular control design process is often employed, wherein the overall design is partitioned into smaller modules. This paper considers a particular inner‐loop/outer‐loop modular control strategy in which the designer of the outer‐loop module does not know the specifics of the inner loop but instead possesses a reference model that captures the ideal inner‐loop input–output behavior. In the first part of this paper, we establish analytical properties of the modular reference‐model‐based design. In the second part, we introduce a novel mechanism, referred to as the modular control error compensation, which mitigates the performance loss that arises when the inner‐loop reference model is not matched. We propose an iterative algorithm, using μ synthesis, to design this compensator to reduce performance loss on the basis of two concrete worst‐case performance metrics. The effectiveness of the modular control strategy with the modular control error compensation is demonstrated through experimental results on an automotive system. Copyright © 2012 John Wiley & Sons, Ltd.