ROBUST POLE-PLACEMENT TECHNIQUE FOR PLANTS WITH ELLIPSOIDALLY UNCERTAIN PARAMETERS

A technique is proposed for synthesizing pole-placement controllers ca pable of assigning the closed-loop poles of a family of plants inside a specified design region. The design is applicable to plants characte rized by uncertain parameters that are known to lie inside an ellipsoi d. Ellipsoidal parametric uncertainty descriptions are particularly us eful because they arise naturally in the context of parameter estimati on, and hence have the advantage of being quantifiable using experimen tal input-output data. The control-design problem is posed as a minima x program that is shown to be convex, and that can be solved using num erical techniques with global convergence guarantees. Two reliable tec hniques for relating regions of stable poles to regions of allowed var iability for the coefficients of the characteristic polynomial are dis cussed. The robust pole-placement design technique is illustrated with an example. Copyright (C) 1996 Elsevier Science Ltd.