Hi,
I am reading about Nyquist stability criterion, and in order to get better understanding I decided to tey a test function of my own. My test function is 1/(s+1)(s-2).
Lets say GH = 1/(s+1)(s-2). Also, I am interested in finding the stability of GH alone and not 1+GH (which is usually done with nyquist criterion). Hence I am concerned about the encirclements only about the origin and not about -1.
Plotting the test function in matlab, I get the attached plot. Since, my test function contains a pole in the right half plane, these should be on counter clockwise rotation about origin. But the figure shows no such rotation. Kindly explain.
Matlab code:
sys = tf([1],poly([-1 2]))
nyquist(sys)
I am reading about Nyquist stability criterion, and in order to get better understanding I decided to tey a test function of my own. My test function is 1/(s+1)(s-2).
Lets say GH = 1/(s+1)(s-2). Also, I am interested in finding the stability of GH alone and not 1+GH (which is usually done with nyquist criterion). Hence I am concerned about the encirclements only about the origin and not about -1.
Plotting the test function in matlab, I get the attached plot. Since, my test function contains a pole in the right half plane, these should be on counter clockwise rotation about origin. But the figure shows no such rotation. Kindly explain.
Matlab code:
sys = tf([1],poly([-1 2]))
nyquist(sys)
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