Formulation of the Stability Margins Clearance Criterion As a Convex Optimization Problem
2009 (English)Report (Other academic)
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 bPCover variations in real uncertain parameters.
Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2009. , 9 p.
LiTH-ISY-R, ISSN 1400-3902 ; 2920
Robust Stability and Performance, Computational Methods, LMI and Convex Optimization
National CategoryControl Engineering
IdentifiersURN: urn:nbn:se:liu:diva-56212ISRN: LiTH-ISY-R-2920OAI: oai:DiVA.org:liu-56212DiVA: diva2:317019