Interval observers for uncertain biological systems

We present a technique for the dynamic estimation of bounds on unmeasured v ariables (or parameters) of an uncertain dynamical system. Our approach is purely deterministic and relies on interval observers: from (possibly time varying) intervals on the uncertainty and measurements, we compute guarante ed intervals for the unmeasured variables. This method is applicable for a class of non-linear systems met in several biological modellings: two examp les are shown, one model of a three stages structured population, and one o f biological water treatment. (C) 2000 Elsevier Science B.V. All rights res erved.