Multi-Model Decoupled Generic Model Control
Authors
James B. Riggs
Peter L. Lee
ABSTRACT
The control performance of GMC (Generic Model Control) using
steady-state models parameter systems can be significantly undermined
by the lack of appropriate dynamic information. A decoupling strategy
has been integrated into the GMC framework in order to compensate for
dynamic mismatch. The approach (Multi-Model Decoupler, MMD) is based
upon using a separate model inverse for the calculation of each
manipulated variable. The additional model inputs provide the extra
degrees of freedom that allow for dynamic compensation. Because the
same model inverse is used for the calculation of each manipulated
variable, the model inverse must be evaluated more often than
conventional GMC would require. MMD-GMC has the advantage over
conventional decouplers since the MMD decoupling elements have unity
gain and thus take full advantage of the nonlinear prediction
capability of the model controller model. An alternative approach
using more traditional External Decouplers (ED-GMC) is developed and
compared to MMD-GMC.
Both approaches are demonstrated on a simulation of a high
relative volatility binary column. MMD-GMC is shown to offer
significant control performance advantages over both ED-GMC and GMC
based on steady-state models and no dynamic compensation.
Publication Information:
Submitted to Journal of Process Control
June 1995
Corresponding Author:
James
B. Riggs
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