I have been given this step response graph and asked to determine the second order transfer function of the system. I completed the question, using a lot of help from this post and got the answers below:
- steady state gain = 2.5
- un-damped natural frequency = 3.18 rad/s
- damping factor = 0.16
I then decided to use ServoCad to produce a graph of my transfer function, to compare against the original and check my answers. This is the graph below. The two graphs look very similar, but on my graph each oscillation appears to take double the time it should on the original graph.
I feel like this is a relatively simple mistake but I'm new to this so if anyone can point out where I've gone wrong I'd be grateful! Thanks!