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Abstract:
A non-linear modification to PI control has been developed
which is appropriate for plants requiring exact set-point matching
and disturbance attenuation in the presence of infrequent step
changes in load disturbances or set-point. This control algorithm,
labeled PII (proportional with intermittent integral), is motivated
by a model of a signal transduction pathway active in mammalian
blood pressure regulation. The proportional aspect of the
controller is independently designed to be a disturbance attenuator
and set-point matching will be achieved by ntermittently invoking
an integral controller. The mechanisms observed in the biological
control model are used to tie these controllers together. Improved
performance over PI control is shown on a model of cyclopentenol
production. PI control fails at the peak operating point as a sign
change in plant gain results in an unstable closed-loop system.
Application of this new approach to this problem results in stable
exact set-point matching for achievable set-points.
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