Anti-Windup Compensators for Multivariable
European Control Conference,
Brussels, July 1-4, 1997.
The aim of anti-windup compensation is to modify the dynamics of a
control loop when control signals saturate, so that a good transient
behaviour is attained after desaturation, while avoiding limit cycle
oscillations and repeated saturations.
We develop a design technique for
model-based anti-windup compensation of multiple-input
multiple-output (MIMO) systems.
It is of advantage if windup
effects can be controlled separately, while leaving the nominal
dynamics unchanged when no actuators saturate.
A controller structure
with three degrees of freedom, with feedback from saturated control
signals, is therefore proposed. The transfer function
of this controller corresponds to
that of a nominal controller, with two degree of freedom, as long as
none of the actuators saturate.
The structure of the controller is selected such that the loop gain
around the bank of saturations is made diagonal. The properties of the
loop around each saturation can then be tuned separately. We propose
one way of doing this, by means
of solving a set of separate scalar H2-optimization problems.
The proposed approach is applicable to continuous-time as
well as discrete-time systems. Although it is here
presented for systems in
input-output form, it can be used in state-space designs just as well.
- Related publications:
PhD Thesis by Jonas Öhr, 2003.
Reglermöte 97 ,
a shorter version.
with details and examples.
described in a report by Rönnbäck and
Postscript, 500K ;
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