Title :
The Zames-Falb IQC for critically stable systems
Author :
Jonsson, U. ; Megretski, A.
Author_Institution :
Lab. for Inf. & Decision Syst., MIT, Cambridge, MA, USA
Abstract :
A feedback interconnection of a neutrally stable linear time-invariant system and a nonlinearity with 0⩽ xφ(x)⩽kx 2 is called critical since the worst case linearization is at best neutrally stable. This makes the stability analysis of such systems particularly hard. It will be shown that an integrator and a sector bounded nonlinearity can be encapsulated in a bounded operator that satisfies several useful integral quadratic constraints. This gives powerful tools for stability analysis of critically stable systems
Keywords :
control nonlinearities; control system analysis; feedback; linearisation techniques; stability; LTI system; Zames-Falb IQC; bounded operator; critically stable systems; feedback interconnection; integral quadratic constraints; neutral stability; neutrally stable linear time-invariant system; nonlinearity; stability analysis; worst case linearization; Actuators; Control systems; Ear; Feedback; Integral equations; Laboratories; Pi control; Robust control; Stability analysis; Transfer functions;
Conference_Titel :
American Control Conference, 1998. Proceedings of the 1998
Conference_Location :
Philadelphia, PA
Print_ISBN :
0-7803-4530-4
DOI :
10.1109/ACC.1998.703286
