M
1
M
3
M
3
’
M
4
J
J
J
J
J
F
1
F
2
M
2
RewinderUnwinder
Driven Rollers
Pendulum Dancers
Figure 6: Scheme of the system under study.
web tension errors smaller than 20 N, as expected (six
sigma design).
5 CONCLUSIONS
A new robust controller synthesis method is devel-
oped using six sigma constraint to tackle with para-
metric uncertainties. A set of values of the uncertain
parameter is computed and statical tools are used in
order to build a set of robust design. This set allows to
build the time domain Pareto in order to ﬁx six sigma
constraint in time domain. The Pareto in closed-loop
frequency domain is also calculated. The two Pareto
curves enable to select the best design.
The methodology is applied on a complex large
scale roll-to-roll model of an experimental plant. The
results are compared with advanced commercial ro-
bust controller synthesis (hinfstruct Robust control
toolbox in Matlab software environment). The sim-
ulations show that the proposed methodology leads to
more robust closed loop system performances regard-
ing the uncertain parameter variations.
Future work consist in integrating other parame-
ters in the optimization process, for example mechan-
ical parameters.
ACKNOWLEDGEMENTS
The authors thank Enginsoft France support, specially
A. Poisson, for the help supplied during the imple-
mentation of the proposed method in the modeFRON-
TIER environment.
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