Any Control Design Expert specifically Digital Control and PID Controllers using Nyquist Plots??.

I have been given a assignment on PID Controllers tuning. I need to investigate Nyquist plot with different values of Kp and Ki and write 4 to 5 lines description of comparison.

I am attaching the Matlab file if you scroll down you will see one assignment.

What I have to do in the assignment I have done and put all the screenshots by varying the values in a word document that I am attaching with this Question.

The only thing you have to do is to write 4 to 5 lines description by analyzing the Nyquist plot that whether the system is stable, unstable, etc. I will be thankful to you for this act of kindness. Reply as soon as possible need urgently.

[vivek rathi]

Walter Roberson Need your help again can you help me in this question. Your help will be appreciated.