Questions tagged [control-system]
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 rockets thrust angle to ensure directional control.
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How can I use MC1489?
I would like to use the interface on link below. I tried to do exactly same except output because to test first, I gave output to LED from microcontroller.
My question is with MC1489. When i connected ...
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1answer
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System architecture for varying number of peripherals [closed]
I have a hardware system, which I need to control/monitor through the PC. There are multiple peripherals which are known, but some might be added in future, and some might be modified later. To be ...
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How to learn PID Control?
I want to learn PID (Proportional–Integral–Derivative) control mainly for temperature.
I would like to learn preferably through an easy project to do.
Could you please recommend something which ...
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330 views
Control System: DC Gain
Mostly, whenever it is asked to find the DC gain of A system; in the solutions provided, they find the steady state error coefficient (corresponding to the Type of the system).
But I figured out that ...
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Help needed using convolution to calculate a system's impulse response
I have a circuit with the transfer function \$G(s) = \frac{1}{(s+1)^2}\$ and I'm asked to calculate the impulse response of the circuit. After looking into it I know that I need to use convolution ...
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What is the mathematical difference between a transfer function and a state transition matrix?
I do know what the difference in meaning is between a transfer function (output over the input) and a state transition matrix $\Phi$ (describes the unforced response of the system). Yet when looking ...
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Gain of an experimental first order step response
I have a pwm driven DC motor control system with magnetic encoder that measures the output shaft speed and outputs the RPM values every 50ms over serial comms to plot a graph of RPM vs Time. The ...
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201 views
Control Loop Stability - Crossover frequency
I am testing the control loop stability of a DC-DC Converter.
One of the Pass-criteria of the DC-DC Converter states, "Cross over frequency should not be higher than 1/8th of switching frequency"
...
Tony Stewart Sunnyskyguy EE75
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1answer
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Relationship between switching frequency and controller's crossover frequency in buck SMPS
Context: tuning the control loop of a buck SMPS. I specicifally have a TI TPS40200-based circuit in mind, but I think this applies to SMPS design in general.
Quoting from Type 2 compensation network:
...
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How to estimate settling time of an overdamped system?
I've been trying to figure out how to estimate the settling time of a second order system in response to a step input of magnitude 5.
The systems transfer function is $$G(s) = \frac{1}{(s+2)(s+4)}$$ ...
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1answer
296 views
How to plot root loci in z plane
How to plot root loci of loop gain G(z)= k/(z-0.5)(z-0.5)(z-0.5) in z plane?
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Advice needed for a final year project on wheelchair automation and control
My project partners and I have been trying to design a wheelchair for people with neuro-degenerative diseases. I know this has been done in the past, however we are using a different approach. We are ...
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Regarding PLC and several input/ output modules
I have to use more than 40 servo motors and 20+ load cells using PLC. But the problem is that I have to use many I/o modules ( that is costly and hectic). Can I reduce the no of I/o modules by any ...
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761 views
how to find frequency of oscillations if a order three system given
Frequency of oscillation in rad/sec of a unity feedback system having open loop transfer function G(s)=K/s^3+3s^2+4s+3 is
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Stability of Differentiator Circuit
let's consider a generic differentiator circuit, i.e. a circuit whose transfer function is \$\text{constant}\cdot j\omega\$. For instance, you may consider this circuit with Op-Amp:
I was reading ...
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158 views
Linearizing hall effect sensors outputs
I'm trying to find a robust solution to linearize four hall effect sensors outout to obtain a signal that I can use in a PID control scheme.
The output data is collect via 4 ADC channels on an ...
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doubt on application of stability criteria
I have only seen systems with this transfer function treated in stability criteria with this general form:$$\frac{KG(s)}{1\pm KG(s)}$$ so the $$\lvert H(s)\rvert =1$$
is it possible to apply criteria ...
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Laplace vs Fourier Transforms in Transmission Lines
Consider an electric transmission line with transient equations
$$\frac{\partial v}{\partial x} =-Ri -L\frac{\partial i}{\partial t}, \qquad
\frac{\partial i}{\partial x} =-Gv -C\frac{\partial v}{\...
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Find the total gain from the following Signal Flow Graph
The signal flow graph for a system is given in the figure. Find resultant gain.
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A current controller by regulating the voltage
I need some idea of what type of controller I should use. But, I am thinking of a PID controller.
Here is my problem:
I have a simple circuit like this one:
simulate this circuit – Schematic ...
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1answer
162 views
Find transfer function and step function for this circuit
Can someone help me to find the transfer function of
this circuit (i want to have the tension through the capacitor I think)
and the step response in order to get the voltage in the function of the ...
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3answers
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How to do the bode plot for this function without Matlab?
I want to plot the bode diagram without any software for
$$G(s)=\frac{(s-2)}{(s^2+4s+15)(s+2)}$$
I do not know how to deal with the factor of \$s-2\$
I will be appreciate if someone can show me your ...
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2answers
114 views
Multiple output Flyback - Stacked transformer - Cross regulation - TL431
Suppose I have the following output stage of a flyback:
simulate this circuit – Schematic created using CircuitLab
The schematic is a bit simplified but the idea is here. Do not pay attetion to ...
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Control software for three phase induction motor
I have been writing a control software for field oriented control of three phase induction motor.
As far as the platform I have been using the FreeRTOS real time operating system. My plan is to
...
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2answers
626 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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design of compensator type 2 for current mode control of boost converter?
I have designed boost converter with Peak current mode control in PLECS. I have used the method of k factor approach to design the compensator. the bode plot transfer function of the power stage is ...
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114 views
How to find the time constant of a water tank control system?
I've come across a scenario where I have a vertical cylindrical tank filled with water, that has an inlet flow valve and outlet flow valve.
Known values:
Resistance or gain R = 1.5 m^3/min
Area of ...
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1answer
181 views
Simple current regulator transfer function
I did simple op amp MOSFET current source. It was not working correctly, it had oscillations as per picture, so RC circuit was was added and problem was resolved. What I am wondering is transfer ...
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2answers
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zero of spring-mass system
I was reading this PDF which tries to explain the concept of poles and zeros of Laplace transform. I started with second paragraph on page #590 and read it up to page #592 before the new section "...
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1answer
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how the area is exactly zero?
I was reading this PDF which tries to explain the concept of poles and zeros of Laplace transform.
My question is about FIGURE 32-5(b) on page #591.
I don't understand why the area is said to be zero ...
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Finding roots of undamped and damped time domain response of a 4th order characteristic equation
A fourth order system is expressed in terms of the characteristic equation as
\$s^4 + 8s^3 + 24s^2 + 32s + k = 0\$
Using the Routh’s array criterion determines the value of the gain parameter k and ...
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1answer
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STEP7 MICROWIN PLC Ladder Diagram
I draw like the first figure in the program, but when I save the program it automatically becomes the second shape. Do the two mean the same thing?
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Matlab transfer functions
I used the "c2d" to discretize a transfer function initially but MATLAB automatically took it as zero order hold because I didn't specify any kind of hold. The result for the zero order hold is ...
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How can a system reach its steady-state if the I-action of a PID controller, u(t), doesn't go to zero as the system approaches its desired value?
The I-action of a PID controller, which integrates the error over time, results in the control signal:
$$u(t) = \int_0^{t}e(T)\text{d}T$$
This means that, when the system reaches its desired value ...
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1answer
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Bode plot display in matlab
I would like to display a bode plot of a buck-boost converter using Matlab, so I got the figure shown below, If we look closer to the phase plot, we see that it starts from 360°.
My wish is to make ...
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Does a circuit graph say anything about controllability of its currents?
Graph of an exemplary circuit can be found below.
Based on this graph, can anything be said about controllability of the edge currents ED, AN, BN and CN if the edges DA, DB, DC, AE, BE and CE ...
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How do i go about finding the transfer function of this system with two inputs?
This was how i tried to formulate the answer but ive been told its incorrect.
$$R(t)=u(t)$$
$$D(t)=u(t)=1/s$$
$$K=10$$
$$H=1$$
$$G=\frac{K}{s(s+1)(s+2)}
=\frac{K}{s^3+3s^2+2s}
$$
If someone could ...
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1answer
259 views
What is difference between natural response and zero-input response of a system and how to find natural response?
In most books it is said that natural response is another name to zero-input response while in some resources is is mentioned that the classification is based on poles of transfer function and input....
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1answer
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Centroid from calculated root locus is different to the one from MATLAB
Hi all hope someone can help me here.
My problem involves the transfer function
G(s)=(s+32.8)/((s+2.8)(s+5)(s+27.8) )
As far as im concerned the centroid is ...
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1answer
139 views
How to find the gain K at break-in and breakaway points of a Root Locus Plot on MATLAB
I would like to know how to find the break-in and breakaway points of a transfer function using root locus on MATLAB.
MATLAB Code:
...
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0answers
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Problem understanding transfer functions of second order filters
The transfer function of any second order filter can be found by analyzing the circuit using the Laplace transform.
For example the transfer function of a second order low pass passive RLC filter ...
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3answers
697 views
State Space model for three-loop circuit
How do I choose the least number of state variables for the following circuit? I started out by assuming currents $$i_{1}, i_{2}, i_{3}$$ in each of the loops and applied KVL, which fetched me three ...
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1answer
61 views
draw a block diagram for the system
A system is represented by the following equation:
$$\frac{𝑑^2𝑥}{𝑑𝑡^2} + 8\frac{𝑑𝑥}{𝑑𝑡} + 9𝑥 = 1$$
By taking the initial conditions, 𝑥(0) = 1, 𝑥̇(0) = −1, draw a block diagram for the
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1answer
265 views
Tuning PID coefficients for stationary stability of brushless DC motors
I'm using a commercial off-the-shelf brushless DC motor controller. It combines a PID controller and an absolute encoder to regulate position. When my motor reaches its target state, it generates a ...
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1answer
180 views
Calculating discrete-time transfer function
I have a continuous function
\begin{equation}G_p(s) = {1\over s^2} \end{equation}
which I am trying to combine with a zero order hold (with a sampling time of 1 second) to produce a discrete function....
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2answers
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Zero in a basic RC high pass filter
If I write the transfer function I can clearly see a zero at zero frequency and a pole at 1/2πRC frequency. But If I simply look at this circuit I would say that there is one pole and no zero(as there ...
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2answers
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Proof for Peak Time for an Underdamped Second-Order System
I've been attempting to prove the taught result that:
$$T_p=\frac{\pi}{\omega_n\sqrt{1-\zeta^2}}\textrm{.}$$
From the time-domain form of an underdamped response, we have
$$c(t)=K_1e^{-\sigma_dt}\cos(...
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1answer
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What is the gain margin of the system, when the phase crossover frequency does not exist?
I have a simple questions
I have a system in which the system will never reach -180 degrees for any frequency.
Does that make the gain margin infinite ?
If yes, does that mean that the system will ...
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0answers
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Desing a PI controller for process with complex conjugate poles
I have a dual-loop control system. In the inner loop, the process is represented by a first-order transfer function. For control I use PI controller. Open loop transfer function is:
$$
G_\text{co}(s) =...
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2answers
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Phase margin vs. damping ratio (non-unity feedback)
So there is a well known condition which relates the phase margin with the damping ratio for a unity feedback system:
$$\Phi_m = \tan^{-1} \frac{2 \zeta}{\sqrt{-2 \zeta^2 + \sqrt{1+4\zeta^4}}}$$
...
