Apologies, not sure where to tag this but If one were to look at a graph and see a response to a step input change, how does one know the difference between a 1st order response and a 2nd order response? one can easily spot an underdamped response straight away, but 1st order response, critically damped and overdamped response all look so similar, is there a key to determining this from a graph?
1st order response
2nd order response
Best Answer
If the curve has an inflection point, then the system is second order. Otherwise, I am afraid that there is little you can do.