Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
In this thesis, a digitalization method with nite word-length (resolu-
) of a given stable analog controller guaranteeing the minimum
dierence in terms of frequency responses is treated. The challenge
has consisted in nding a relevant frequency responses mismatch met-
ric and in relating it to the word niteness issue. The analog con-
troller is represented in modal state-space form and digitalized with
a stability-maintaining approximation (ramp invariance) for dierent
sampling periods. It results in digital controllers with block diago-
nal transition matrices whose coecients (poles) are inside the unit
circle. The format is chosen to match the poles dynamical range.
The matrix is then coded and the mismatch measure allows for the
selection of the "best" poles coded controllers. The remaining ma-
trices are then scaled and coded for these selected controllers. The
measure is computed for each of them. The procedure nally gives
the "optimal" coded controller. This algorithm is shown to perform
well and better that a simple rounding after the analog controller
2012. , 91 p.
Dimarogonas, Dimos V.