Questions tagged [root-locus]

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How to find the gain K at break-in and breakaway points of a Root Locus Plot on MATLAB

I would like to know how to find the break-in and breakaway points of a transfer function using root locus on MATLAB. MATLAB Code: ...
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1answer
53 views

Digital Root Locus in Scilab

I have the following digital plant: \$G(z)=\cfrac{z+1}{(z-0.3)(z-1)}\$ I want to use root locus to design a system with: (1) position error=0; (2) overshoot \$\leq 10\%\$ (3) settling time \$\...
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1answer
60 views

Design a digital controller for minimize the settling time

I have a system of digital control with unitary feedback, with the following transfer function: $$G(z)=2\frac{(z-0.5)(z-2)}{(z+0.2)(z+1.5)}$$ I need to use a digital controller: $$C(z)=K\frac{z-\...
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1answer
70 views

Root Locus in a feedback loop

I'm trying to draw Root Locus by hand from the following block diagram and confirm the result I got from Routh Hurwitz's table: The table of Routh Hurwitz that I got is the following: And from the ...
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1answer
54 views

Given desired overshoot graphically find k from the root locus (Scilab)

I want to find \$k_1\$ that leads to the feedbakc system having poles in the 53º line (to have overshoot \$\leq 10\%\$). From the root locus, the poles move along the vertical asymptote centered on -1....
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1answer
211 views

find a point on root locus for specific damping ratio?

I have faced many type of root locus which some of them have curved behavior. I cannot find the poles for my system that has damping ration without using MATLAB. I need somehow to find the ...
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0answers
19 views

Break away points

If there are two break away points between two poles, then what will be the nature of root locus? How to deal with them, and same question in case of 2 break-in points between two zeros.
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1answer
133 views

Does this Root Locus analysis contradict my understanding of Nyquist stability criteria?

I have been trying to theoretically analyse the operation of a 741 op-amp from a stability point of view by firstly deriving its open-loop transfer function. Here is the magnitude plot of a 741 op-...
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2answers
61 views

Confusion regarding root locus. Open loop or close loop?

Which transfer function ,open loop or close loop do we use/need as a pre req to perform root locus analysis? I have also attached a snapshot of the relevant webpage of university of Michigan. I have ...
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0answers
18 views

Root locus vs routh hurwitz criteria?

What is the difference between root locus and routh hurwitz criteria? As according to layman knowledge, both techniques are used somehow to determine
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2answers
49 views

How to identify branches of root locus from figure/plot?

How can we identify the branches in a root locus For example How many branches do we have in this below root locus(i feel from its appearance to have one branch) And how many branches in this below ...
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1answer
66 views

How can I prove that for any control system root locus plot starts from poles of OLTF and ends at zeroes of OLTF?

simulate this circuit – Schematic created using CircuitLab G(s)H(s)=N/D T(s)=KN/(D+KN) Proof: ] But For K=0 T=0 For K=infinity T=infinity then how can K=0 {condition where forward path ...
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0answers
73 views

Gain margin using Root locus plot

How can I find Gain margin of any control system given its polar plot In schaum's series I have read that Gain Margin=Ku/Ki but in given figure the system never becomes unstable so shouldn't Gain ...
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2answers
418 views

Relationship Between Root Locus Pole and Percent Overshoot and Gain in MATLAB

I have a peculiar confusion regarding the relationship between a closed-loop pole on a root locus plot and its gain and percent overshoot. I have found a point on the root locus plot that MATLAB ...
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1answer
66 views

Steady error control system sinusoidal disturbance

Consider the control system closed-loop represented such a block diagram below: Given that: \$G_C(s) = K\$ and \$G(s) = 1/s\$ a) Determine the values of \$ K\$ which the closed-system loop is stable....
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3answers
297 views

Root Locus, Gain in Feedback Loop. Need help

So this is the system for which I have to draw a root locus if 'K' changes from 0 to infinity. The problem for me is that root locus is drawn for open loop transfer function but 'K' is in the feedback ...
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1answer
389 views

Pole Zero Cancellation on a Root Locus

Question: ...design a controller in the feedforward path to minimise the effects of the two pairs of dominant poles. Use a pole-zero cancellation technique on a root locus diagram.... I have a 5th ...
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2answers
178 views

Root Locus and Imaginary Axis

I’m having some serious issues finding the point at which the root loci cross the imaginary axis for the following Open Loop Transfer Function (OLTF) ; We have been taught to substitute s = jw and ...
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1answer
152 views

How to calculate roots using root locus method? [closed]

Find the roots of the following polynomial by use of the root locus method. 3s⁴ + 10s³ + 21s² + 24s + 30 = 0 (The root locus plot has not been given.) Can you please help me with this? This ...
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2answers
104 views

Root locus, where do they leave the line parallel to imaginary axis

I know how to sketch by hand root locus of simpler systems. Consider the root locus which Matlab gives for: $$G(s) = \frac{1}{(s+4)(s+6)(s^2 + 10s + 100)}$$ I've marked the points of interest P1 and ...
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1answer
307 views

Root locus for an open loop transfer function?

The function, rlocus(), in MATLAB is used for closed loop system roots for variation in gain K. However, I am curious if there is a similar function for variation ...
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0answers
484 views

Designing PID controller for 2 servo motor synchronization

I am trying to use a PID controller to synchronize wheel speeds in an arduino-bot so that I can get it to drive straight. I am unsure how to approach this problem without knowing the physical ...
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2answers
2k views

How to find the intersection point in rootlocus diagram?

Question: Sketch the root locus for the open loop transfer function of a unity feedback control sytem given below and determine the value of K for \$\xi=0.5\$ \$G(s)=\frac{K}{s(s+1)(s+3)}\$ --...
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0answers
102 views

Question about the transfer function found from state space model

I'll make up a problem to explain what I'm having trouble with. $$\dot x=\begin{bmatrix}0&1\\-5&-6\end{bmatrix}x+\begin{bmatrix}0\\1\end{bmatrix}u=Ax+Bu\\\\y=\begin{bmatrix}0&1\end{bmatrix}...
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3answers
8k views

Determining imaginary axis crossing of a root locus

I have an equation \begin{equation}{\text{L}\left(s\right)=\frac{K}{s(s+4)(s^2+6s+64)}} \end{equation} and I am trying to determine it's root locus by hand.When I try plotting it with matlab, the ...