摘要：This paper deals with a robustly stable adaptive
pole-placement-based controller for time-delay linear systems with
unknown point delays within known intervals of sufficiently small
lengths under unmodeled dynamics and bounded disturbances. A
multiestimation scheme is used to improve the identification error
and then to deal with possible errors between the true
basic delays compared to that used in the regressor of the
adaptive scheme. Each estimation scheme possess a relative dead
zone for each estimation scheme which freezes the adaptation for
small sizes of the adaptation error compared with the estimated
size of the contribution of the uncertainties to the filtered
output. All the estimation schemes run in parallel but only that,
which is currently in operation, parameterizes the adaptive
controller to generate the plant input at each time. A supervisory
scheme chooses in real time the appropriate estimator subject to a
minimum residence time which is the tool to ensure closed-loop
stability under switching between the estimators in the estimation
scheme. The dead zone adaptation mechanism prevents the
closed-loop system against potential instability caused by
uncertainties.
