I've been working with Simulink for quite a while already, but now encountered a
seemingly simple and common kind of problem, which I still can't seem to find a
general solution for. That is, how do you utilize the not-the-very-elementary
Simulink blocks for creating time-variant systems?
For example, say you want to simulate the output of a 2nd order linear system by
using the Transfer Fcn block. The coefficients for the numerator and denominator
polynomials are given as coefficient vectors in the block input dialog. Is there
any means to input these coefficients as a function of time? (The Simulink-time
Of course one can always transform the simulated function back to time-domain
and build the system from scratch (multipliers, integrators/derivatives etc.) -
i.e. workarounds may exist - but that's not the point here. (Imagine you
So, is there a way, e.g. by using the Matlab workspace or by using some nice
variable definitions in Simulink or by some other means I'm not aware of to
generally utilize time-variant parameters in Simulink blocks.
-Antti Pohjoranta, Helsinki