A system that may be electronic circuits or even software that uses control theory (principally differential equations) to control an output by monitoring various aspects of the system under control and varying inputs all towards meeting a defined goal. Some famous examples are controlling a ...

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49 views

Practical Implementation of Smith predictor

I am now dealing with Smith predictor and I understand that it's based on model of the controlled plant. This model I can get by some identification method, but such a model will never be absolutely ...
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1answer
34 views

what type of modification can i use in my MCU in conjunction with my SSC32?

Hello there guys im looking for a way to connect and use a DC motor with a Servo controller such as the SSC32? now given the fact that a Servo controller or driver has 3 pins, PWR GND SIG/PULSE now ...
-3
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0answers
17 views

I am looking for a delay switch with a momentary contact to delay the extinguishing of 2 LED's running on 3-4.5v [on hold]

I am looking for a delay with a momentary contact switch, to delay the extinguishing of 2 LED's running on 3-4.5v. The parameters are: The LED's need to glow for about 2 minutes; The device is to be ...
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1answer
47 views

Lead Compensator for double integrator

I am an autodidact in control engineering and I have been trying to design a lead compensator for double integrator system so that the closed loop poles have damping $$\zeta=0.5$$ and natural ...
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1answer
52 views

Input/output for buck-boost converter controller implemented with FPGA

I am trying to implement a voltage controller for a buck-boost converter using FPGA. The control method I'm trying to use is in this paper: www.engr.iupui.edu/~aizadian/index_files/Papers/C-28.pdf ...
3
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2answers
53 views

How to determine sinusoidal steady state response from bode plot

I'm given a problem by the following: Find the sinusoidal steady state response (in the time domain) of the following systems modeled by transfer function, P(s), to the input u(t). Use the Bode plot ...
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1answer
28 views

Feedback Control: Unexpected result for block diagram simplifications using matlab

I made some simple calculations regarding block diagram algebra. The problem is that I don't get the same result using matlab. Here is the system with it's corresponding blocks: $$H_1 = z+2$$ $$H_2 ...
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1answer
45 views

designing PID controller using Ziegler Nichols algorithm

I'm trying to use Ziegler Nichols algorithm to design PID controller for the following transfer function: G=w^2/(2*xws+w^2), w=1 , x=0.2. so since the step response for this function is a second ...
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2answers
54 views

Root locus of discrete time system

I have a question about a probably easy task, but I can't find the right K. I have the loop with an adjustable gain element given: $$Q(z) = \frac{H(z)}{1+ K\cdot G(z)H(z)} $$ I have given: $$H(z) ...
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3answers
58 views

Can 3-phase FOC control be done without current measurement?

Can a FOC control scheme be done using a rotary encoder to measure the position, speed and acceleration directly, or is measuring current necessary? FOC is a motor control scheme as described in ...
4
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3answers
126 views

How to measure temperature of a syrofoam cutter hot wire?

I would like to create a hot wire foam cutter device. The wire material is nichrome, diameter 0.9mm, resistance is about 1.7 Ohm/meter. For best cutting results, I would like to control the ...
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2answers
69 views

Control system stability with respect to gain margin and phase margin

I have learn from control system that for a stable system gain margin and phase margin both must be positive. That is the truth. But I have a doubt about this simple third order type 2 open loop ...
0
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2answers
69 views

Stability of a differentiator

I'm a bit confused regarding the stability of a differentiator and an integrator. When an integrator is added to the system it decreases the stability as it adds a pole at origin and bends the root ...
0
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3answers
122 views

How actually an integral transformation(Fourier and Laplace) works?

After seeing a question on one of the posts I got this confusion in my mind. Here I'm not much interested in just mathematical explanation but I would like to know how a transformation actually turns ...
3
votes
5answers
94 views

Laplace transform and the idea of frequency domain analysis

I have studied control theory in depth in my undergrad and still continue to use it on many occasions in my PhD work, but i still don't fully understand why we call Laplace transformation of system a ...
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2answers
54 views

How to perform a \$\dfrac{1}{s+a}\$ type integration in MATLAB?

Currently, I am integrating an ODE of the form \$\dot x = f(x,t)\$ in MATLAB using the function ode45 This is equivalent (in block diagram form) as passing \$\dot x\$ through an integrator ...
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1answer
51 views

Control theory - how to represent these transfer functions?

I'm learning control theory. Block diagram for transfer function: is: What would be block diagram for these two transfer functions: $$H(s)=\frac{1}{s^{2}+1}$$ and $$H(s)=s\frac{1}{s+1}$$?
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3answers
62 views

Finding Open/closed loop transfer function

I plan to determine the open/close loop transfer function of the attached motor. I have been able to combine K(s) to 1/s in series but am not too sure of how to add up 12/pi outside the summing ...
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1answer
37 views

Design a P-Controller given the root locus ?

I used to have the transfer function given but here the root locus instead ... Can one help with the start...
0
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1answer
58 views

problem : find the coefficients of linear system used to build a digital oscillator ..?

Please can one explain to me I having difficulty on how to start Thank you all *** can anyone correct me if anything is wrong !
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0answers
27 views

How to determine the stability from Nyquist plot for Minimum and Non-Minimum Phase system?

For a non-minimum phase system there are some zeros that are in the RHP of S_plane and since the Nyquist plot Does't encircle the origin there Must #of pole in the RHP that equal to # of zeros In ...
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0answers
50 views

Why are digital systems guaranteed to be unstable for some gain while continuous ones aren't?

I was reading a book on digital systems and it said that all systems (I assume it meant only digital) will eventually become unstable for some gain and it got me thinking. I know that in continuous ...
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0answers
52 views

Nyquist criterion and the gain/phase margin of transfer function?

Now to determine gain/phase margin I need the bode plot. and to find the value of k such that the system is stable I have to do Nyquist criterion for the closed loop transfer function. (Question: ...
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1answer
40 views

Determine unhampered natural frequency and motor constants from graph?

I can find zeta from the PO given in the graph but I don't know any rule relate wn with tp and I don't have value of the of ts and tr For part b and c I don't know where to start please help me ...
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1answer
51 views

System response with initial condition

I have a small problem figuring out how to properly solve that. I could use help. Say a system with a transfer function \$ H(s) = \frac{100}{0.4s + 1} \$ is excited with an excitation \$u(t) = 8V\$ ...
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1answer
50 views

Quick question about a closed loop control system

Using above loop, we see that \$ \dfrac{y(s)}{r(s)} = \dfrac{p(s)c(s)}{1+p(s)c(s)} \$ and \$ \dfrac{e(s)}{r(s)} = \dfrac{1}{1+p(s)c(s)} \$ (well known results) Why is that: If the close loop ...
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4answers
117 views

How can i extract transfer function an unknown nonlinear system?

I am trying to do PID control for my electroservo motor system by using nichols ziegler tuning method. My system has SSI encoder output for motor feedback mechanism. I will use this knowledge for ...
1
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1answer
43 views

Does movement along the imaginary axis of a root locus change the natural frequency?

I have two root locus plots (x-real, y-imaginary) of the same oscillating mode: (1) for a base case system and (2) a system with added feedback. They are so similar, almost identical that I am having ...
2
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3answers
97 views

Automatic calibration of a zero cross detector latency

I have a circuit similar to this one (different component values, different uC): I expect a large phase error in the ZCD. The load is purely resistive and of unknown value between 100W and 1000W. ...
3
votes
2answers
101 views

Systems stability with zero poles

I have a rather simple question I would say. I know that systems having real poles to the right side of the plane will inevitably be instable (for LTI systems at least). But I'm confused with ...
3
votes
5answers
143 views

Explanation of 2nd order transfer function

I am reading about the 2nd order transfer function of a 2nd order system (like the mass-spring-damper system). I am constantly seeing the following form as the standard one: \begin{equation} H(s) = ...
0
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1answer
64 views

CONTROL CIRCUIT : Question Regarding Voltage and Resistance

I was wondering, whether my explanation was correct or not. I checked with online sources and they say I was incorrect, but I cannot understand how I am incorrect. As the resistance increases, ...
2
votes
2answers
58 views

Is it possible for two different systems to have the same step response, and vice-versa?

Every time I have had to tune a controller (PID, usually) to a process, I have first matched an equivalent first order or second order model by doing some curve fitting on the step responses; and then ...
4
votes
1answer
75 views

Interpreting bode plot of type 3 compensation network for buck regulator

I'm struggling to design the type 3 compensation network for a simple buck PWM controller. The controller is a Richtek RT8110B. According to the datasheet, half of the type 3 network is in-built and ...
0
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1answer
59 views

Step response of feedback system

We have a feedback system F(s) as in this figure: and this is the step response of G(s): and H=10. F(s): We got the root locus of the system F(s) as this: then we determined the gain ...
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2answers
148 views

Why are linear systems poor oscillators?

Given a linear system with initial conditions. If you have conjugate poles in D(s) that lie right on the jw axis, you should, in theory, be able to get sustained oscillations that do not grow unbound ...
6
votes
3answers
369 views

How to tune a PID controller to a nonlinear process

I have a nonlinear thermal process (nonlinear radiation becomes more and more present as temperature goes up) that I would like to tune a PID controller to. I'd like to control the temperature as ...
0
votes
1answer
51 views

evaluate number of poles lying on the right,left side of s-plane and on the jw-axis? [closed]

the transfer function is \$\ T(s)= \dfrac {1} {2s^5+3s^4+2s^3+3s^2+2s+1} \$ I solved it using RH criterion by evaluating the columns but results are different when i solved it with by matlab they ...
3
votes
2answers
52 views

Equilibrium points of a circuit with a diode

The given circuit is shown in the first picture, whereas the characteristic curve of the diode in the second one. I want to calculate a model in the form of $$\frac{d\textbf{x}}{dt}=f(x,u) \\ ...
0
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2answers
68 views

What supplies ATS control circuit when the mains fail?

In a church, I've seen a large generator and ATS panel (automatic transfer switch) so that the generator turns on when there is a failure in the mains. If there is no power in the mains, How does the ...
0
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2answers
57 views

root locus of \$t(s)=\frac{K(s+2)}{(s+3)(s^2+2s+2)}\$?

I calculated the breakaway points. They come out to be Root 1: -2.481 Root 2: -0.689 Root 3: 1.17 because of root locus properties only the -2.481 will fall on root locus . But when I saw the ...
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vote
2answers
76 views

Bode plot of poles that are close to each other

I have a transfer function of the following form: \$\ T(jw)= a0 / (1+ s/w1) (1+ s/w2) (1+ s/w3) \$ where a0 = 3600 w1= 1MHz w2= 4MHz w3= 40MHz I drew the the bode plot and double checked with ...
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2answers
76 views

Block Diagram Reduction

Could anyone help me with the start, I don't how to begin?
2
votes
2answers
96 views

Why is this second order system difficult to control?

Why is system of the type $$T = 1/(s^2 - 1)$$ Difficult to control using standard control methods? When I look at frequency plots, it doesn't seem to give me any important information as to why ...
11
votes
2answers
328 views

How do I size the output capacitor for a DC bench power supply?

I'm designing a DC bench power supply and have come to the matter of choosing the output capacitor. I've identified a number of related design criteria, but I'm finding my reasoning still going a bit ...
2
votes
0answers
97 views

Deriving PI controller transfer function when input is reversed

I'm developing the compensator for the linear DC Bench Power Supply I'm designing. As I've come to deriving the transfer function for the op amp-based compensator, I realize I've been depending on a ...
5
votes
2answers
99 views

Control theory: is there any actual application for D in ABCD matrix?

Recall that a LTI state space of a dynamical system is given as: Is there any actual purpose for D in the output equation? If D was not zero, it would mean that the output is "directly" ...
2
votes
2answers
131 views

Is a Type 2a PID(ish) controller just an example of an augmenting integrator?

In a previous question I finally cracked the code on deriving for myself the transfer function for a Type 2(a) compensator like this one, built around an op amp. As it turns out, for AC analysis ...
5
votes
2answers
183 views

What is this RC local feedback configuration?

I'm studying power converter control loops using Christophe Basso's book Designing Control Loops for Linear and Switching Power Supplies. A very common pattern in the compensator circuits is a ...
2
votes
4answers
72 views

Getting transfer function from block diagram

I am having trouble figuring out this step in an example question I've been given. I'm supposed to be finding the 'transfer function in the forward path'. This image shows the block diagram (top) ...