S F Graebe and
In WS Levine , ed:
CRC Control Handbook , CRC Press, 1996.
Also: Internal Report UPTEC 96070R, Dept. of Technology,
This chapter discusses the problem of bumpless
transfer, which is concerned with smooth switching between
alternative dynamical systems.
A number of situations are highlighted in which this problem
arises, including switching from manual to automatic control, on-line
re-tuning of filter or controller parameters and tentative
evaluation of new controllers during normal plant operation.
If it is possible to manipulate the states of the controller directly, there
are several techniques to compute the value of the state vector that
will give the desired output. If it is not possible to manipulate the
states directly, such as in an analogue controller, then
the input to the controller can be used instead. Viewed in this way,
bumpless transfer becomes a tracking problem, in which the inputs
to the controller are manipulated so that its output will track
an alternative control signal.
Once bumpless transfer is recognised as a tracking problem, systematic
design techniques can be applied to design appropriate tracking
controllers.Advantages with this approach are outlined
and its relation to some other known techniques is discussed.
- Related publications:
Paper in IEEE Trans. CST 1996 on
the above theme.
Report on a systematic technique
for scalar anti-windup design.
Conference paper (Reglermöte 96)
on multivariable antiwindup design.