Paper Info
Title
A convex characterization of gain-scheduled H/sub /spl infin// controllers
Abstract
An important class of linear time-varying systems consists of plants where the state-space matrices are fixed functions of some time-varying physical parameters /spl theta/. Small gain techniques can be applied to such systems to derive robust time-invariant controllers. Yet, this approach is often overly conservative when the parameters /spl theta/ undergo large variations during system operation. In general, higher performance can be achieved by control laws that incorporate available measurements of /spl theta/ and therefore "adjust" to the current plant dynamics. This paper discusses extensions of H/sub /spl infin// synthesis techniques to allow for controller dependence on time-varying but measured parameters. When this dependence is linear fractional, the existence of such gain-scheduled H/sub /spl infin// controllers is fully characterized in terms of linear matrix inequalities. The underlying synthesis problem is therefore a convex program for which efficient optimization techniques are available. The formalism and derivation techniques developed here apply to both the continuous- and discrete-time problems. Existence conditions for robust time-invariant controllers are recovered as a special case, and extensions to gain-scheduling in the face of parametric uncertainty are discussed. In particular, simple heuristics are proposed to compute such controllers.
Year
DOI
Venue
1995
10.1109/9.384219
IEEE Transactions on Automatic Control
Keywords
DocType
Volume
Uncertainty,Robust control,Control systems,Time varying systems,Switches,Robust stability,Current measurement,Control system synthesis,Linear matrix inequalities,Processor scheduling
Journal
40
Issue
ISSN
Citations 
5
0018-9286
61
PageRank 
References 
Authors
15.32
2
2
Name
Order
Citations
PageRank
Pierre Apkarian1635108.90
Pascal Gahinet222977.15