# Identification of the system with zeros

I need to identify two systems. Those are their Unit Step responses:

I don't know, what order of the system that is. It could be second order system with zero in 0. Lecturer told me it was third order system, but then told me to solve it as second order system, so I'm a bit confused. More over we don't have materials for those systems, which would show us how to idnetify them. Lecturer told me to search it on the internet.

So I wonder whether anyone could give me some hint or better, if anyone could explain how to solve this or what kind of system those systems are.

I would welcome some good materials for this task.

• Looks more like a system with a pole in the LHP rather than a system with a zero. Commented Mar 10, 2014 at 19:04
• ok. If that is 1st order system with pole in LHP, it wouldn't oscilate. If that is 2nd order system with no zeros, only poles in LHP, it would have non zero signal in infinity. I didn't find any system, that would have value in infinity equal 0 and wouldn't have zero in 0. But then again, I didn't see much systems. So which for example would behave like that? Commented Mar 10, 2014 at 21:32
• I think a voltage regulator or any DC-DC converter can produce those signals. Try 3 poles and 1 zero first.
– user23972
Commented Sep 30, 2016 at 8:48