Calculating Settling time in Matlab, different from stepinfo

I would like to compute the settling time of a signal y in Matlab. It should give the amount of time required before the signal reaches a steady state error y(t)-y_{ss} which is smaller than some absolute value x and stays smaller than x for all future times.

I already tried to use the Matlab function stepinfo, but this defines the value x as "a fraction 2% of their peak value for all future times" and that is not what i want.

Is there any way that i could adjust the Matlab function stepinfo, that i could code this myself or perhaps there is another function available that calculates the settling time in this way?

Answer 1

[Greg Dionne]

Are you analyzing a step or a series of steps? Try settlingtime() if you have the Signal Processing Toolbox. That defines the termination condition as being within a given tolerance of the final state level over a specified minimum duration.

[Bart Nijman]

no i'm not analyzing a step change, it is not a SISO system. I have now already written my own code for it, thank you.

[Bart Nijman]

this is the code for anyone interested:

SettlingTime = tspan(find(y>error,1,'last')).

turned out to be quite simple.