Formulation of the Stability Margins Clearance Criterion As a Convex Optimization Problem
2009 (English)In: Proceedings of the 6th IFAC Symposium on Robust Control Design, 2009, 325-330 p.Conference paper (Refereed)
This paper presents the formulation of a flight clearance criterion as a convex optimization problem. The criterion is the stability margins criterion which is specified as an allowable phase and gain margin of a certain loop transfer function. The satisfaction of the criterion amounts to the Nichols plot of the loop transfer function being outside a specified trapezoidal region. It was shown previously that the exclusion condition from an ellipsoidal region is implied by using the generalized stability margin bPC and its calculation was performed frequency-wise by solving a sequence of convex optimization problems. In this paper we formulate the calculation of a lower bound on bPC as a convex optimization problem using Integral Quadratic Constraints (IQCs) and avoid the gridding procedure in the frequency domain. Furthermore, we formulate the problem of obtaining a lower bound on the perturbed stability margin, which is defined as the worst-case bPC over variations in real uncertain parameters.
Place, publisher, year, edition, pages
2009. 325-330 p.
Robust Stability and Performance, Computational Methods, LMI and Convex Optimization
Computational Mathematics Engineering and Technology Control Engineering
IdentifiersURN: urn:nbn:se:liu:diva-21938DOI: 10.3182/20090616-3-IL-2002.00056ISBN: 978-3-902661-45-6OAI: oai:DiVA.org:liu-21938DiVA: diva2:242268
6th IFAC Symposium on Robust Control Design, Haifa, Israel, June, 2009