Liliput

Hi, i'm new to system identification area. That's why please look at the frequency response and tell me what do you see? I'm concerned beacuse the phase is jumping so rapidly, which let me think that there are several D-parts in the process. My gues is 4 Then several I-parts 2. Right? How can i filter out all small Magnitudes let say bellow 20 (Graph not in DB). The Bode plot from the parametric estimation model is on the second screenshot. What i'm willing to do is to become a system that detects the peaks in the frequency after applied to the input signal. How can i do it? Every help is appreciated!