Control Systems · Digital lecture note
Lecture 12 – Positive feedback root locus, lead/lag compensators
Kontrol Sistemleri – Positive feedback root locus, lead/lag compensators
- Course
- Control Systems (ELEC322)
- Semester
- Semester 6 · Spring 2023–24
- Format
- PDF · 13 pages · 0.5 MB · handwriting-style LaTeX
- Language
- Turkish
- Original note
- Control-Systems-lecture-12.pdf
Open the PDF (0.5 MB)LaTeX source (.tex)Original handwritten note

What is in this note?
Section headings of the note (in Turkish):
- Positive Feedback architecture
- Compensator design
- Adding poles
- Lead compensator: zero is closer to jω axis
- Lead lag compensator
Text of the note
Show as plain text (Turkish; formulas and drawings are not included)
Positive Feedback architecture
(2) Departure angles from complex poles
arrival '' to complex zero
departure angle = 360 +Σ phase of c.c pole w.r.t. other poles
-Σ phase of c.c pole w.r.t. other zeros
Positive feedback system
To find characteristic equation
if its negative feedback
specific `` k '' which renders the system unstable
4 seperate roots of ch.e.q.
Its unuseless itself so we have to add a pole
by adding poles the locus plot move to right, systems get more unstable. (lag compensator)
System get more unstable - slower! ( t_s )
More accurate by adding integrator
lag compensation, The output angle is less than input
pulls the root locus plot to the left
more sensitive to noise
The output angle is more than the input angle
its leading output
lead laging compensator
Series/parallel compensation
Lead compensator: zero is closer to jω axis
if α>1 ⇒ lag compensator
Lead lag compensator
Dominant pole =-3+2j → lead compensator
Steady state error =10% (step input) → lag compensator
k give dominant pole