[moved] Root Locus Sketch (which locus will choose which path)

[Eshal]

Hi all,

I have a question to sketch the root locus of the below given figure.


I sketched its root locus in MATLAB and found this locus.


From this MATLAB's figure we can see the locus coming from pole at 0 is going downward and ends to zero at -2. Similarly, locus coming from pole at -1 is going upward and ends to zero at -3. We can see which locus is following which path. But when I see this figure in book then I don't know locus from pole at 0 is going upward path or downward path. Similarly, locus from pole at -1 is going upward path or downward path. see below book image of the sketch.


Is there any technique to know which locus will take which path upward half circle or downward half circle? If there is any calculation to know this then tell me.

Thank you very much.

Regards,
Princess

 

[D.A.(Tony)Stewart]

Re: Root Locus Sketch (which locus will choose which path)

use s= 0 and see resuly and check polarity and check polarity of s starting near 0.
then IF you quick differentiate product terms and do same.