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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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3answers
13k views

What should be DC gain of the system?

Step response of system is \$c(t) = 5 - 0.5e^{-2t} + 8e^{-t}\$ then find steady state gain. Answer is -7.5 Now in book solution is given as : Since this is step response we will find impulse ...
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How does control theory apply to my real-world processor-controlled boost converter?

I have a limited understanding of control theory. I dealt with poles and zeroes and transfer functions in school. I've implemented several microprocessor-based control schemes for DC/DC converters. ...
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2answers
89k views

What is a “dry contact input”?

I'm a PC software guy, a newbie to electronics. Recently, I've got a project in which I need to source for a DAQ that can provide dry contact inputs to an interfacing digital output controller. The ...
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1answer
141 views

Signal flow simplification

I've looked at the various simplifications that can be made for signal flaw diagrams to combine branches; however, I can't work out how one can apply a transformation to simplify the following ...
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2answers
1k views

Can you control a 12V Solenoid Valve using motor dev kit MCLV-2?

The MCLV-2 is a motor driver development board, of 24 volt and up to 15Amp (in total). Aside driving a motor, I'm also interested in testing to see if these circuitries are suitable to run a 12 volt ...
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31k views

Undamped natural frequency

What's the definition of the undamped natural frequency? I've looked and I cannot find it. A second order system has the following transfer function $$ H(s) = \frac{A_o \omega_n^2}{s^2 + 2 \zeta \...
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1answer
8k views

What are the major advantages of using a closed-loop over an open-loop and vice versa?

I'm trying to gain a better understanding on the pros and cons using closed-loop or open-loop motor control. Also trying to better learn when it's more sensible to apply each one
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Conditional stability

I'm learning about op-amps and feedback and how feedback affects their stability. I've been reading about gain and phase margin and their uses when I came across this: I don't quite understand how ...
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1answer
409 views

PID controller, tuning and creation

I have been having some good success with my first PID controller. It seems it needs just a little bit more work. Below is a picture of a sample run with my controller implemented. Currently I only ...
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2answers
4k views

Does gain affect stability of a Transfer Function?

I have a control system that we are working on with a forward transfer function of:- \$ \dfrac{K(2s+3)}{s^2(s^4+2s^3+4s^2+2s+7)}\$ So I've set up the routh table for this, I've found there are 2 ...
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1answer
14k views

The open loop transfer function of a unity feedback control system is given as \$G(s) = \frac{as+1}{s^2}\$

The open loop transfer function of a unity feedback control system is given as \$G(s) = \frac{as+1}{s^2}\$. What value of 'a' will give a phase margin of 45° ? \$G(s) = \frac{as+1}{s^2}\$ \$Transfer\...
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1answer
2k views

Rise time for second order RC filter?

Can somebody help me in deriving the expression for rise-time for second order RC filter. simulate this circuit – Schematic created using CircuitLab
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3answers
657 views

I need help Building A Solid state Electro magnetic Mixer

I'm just getting into electronics, and I would like to build an electromagnetic mixer. See here. Most of the tutorials I have found have magnets stuck to a motor spinning under a non magnetic material ...
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2answers
1k views

Determining whether a system is LTI given response to a rectangle box input

Given a system, it is possible to determine whether the system is LTI given the response to input to the system, other than the unit impulse? Specifically, my input to the system is $$x(t)=\begin{...
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2answers
96 views

Definition of a System

A mathematical operator is generaly a mapping between a domain set of functions and a range set of functions.One example is the derivative operator L ( L[f] = f' ) for example. Can i say every ...
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1answer
3k views

bldc motor torque controller

I have a working custom motor controller for three phase sensorless bldc motors. I've implemented open loop speed control, where the duty cycle is changed to change speed. I've also implemented a ...
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1answer
78 views

LTI Response Help

A system is known to be LTI. The response of the system to a step function u[n] is δ[n] + δ[n-1]. a.) Find the response of the system to 2u[n] + u[n-1] b.) Find the response to the unit impulse δ[n]....
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3answers
4k views

Variable liquid flow rate control

I'm not an Engineer by trade, rather a programmer looking to put together a micro controller project that alters the water flow rate of a cooling system to maintain a specific operating temperature ...
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1answer
1k views

Working of ac servo drive in position control mode and algos for position control

I have started working with a Panasonic AC servo drive of capacity 400W (manual). While trying to understand how a ac servo works in position control mode. After experimenting I have come to the ...
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2answers
159 views

Control system to minimize a parameter [duplicate]

This is a pretty vague question so please bear with me. I can add further information if required; just let me know in the comments. So here is the problem that I want to solve. There is a system ...
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1answer
656 views

Designing a PI controller for my power system

I have a power system which is given as: Using MATLAB, I found the system's response to be: As you can see, the system is not stable. So, I need to design a PI controller, so that, the transient ...
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1k views

PID Control Loops with large and unpredictable anomalies

Short Question Is there a common way to handle very large anomalies (order of magnitude) within an otherwise uniform control region? Background I am working on a control algorithm that drives a ...
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1answer
877 views

How can I model this linear power system in MATLAB?

For my power system, let us suppose it has the following dynamic model: \$\ x ' = f(x,u)\$. This dynamic model consists of four first order differential equations (see below). Then, I linearized ...
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4answers
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PID regulator steady state error problem

I'm working with a PI controller that regulates temperature through a pwm duty cycle. It generally controls well. However, the system requires a certain minimum duty cycle to balance the heat loss. ...
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3answers
11k views

Detecting dry-running of water pump

What are some reasonably reliable ways of detecting that a water pump (electrical motor based) is "dry running", i.e. no water is passing through the pump either because there is no water available at ...
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1answer
114 views

Reticulation Controller [closed]

I'm thinking of building my own reticulation controller to drive an automatic watering system. Does anyone out there have a good circuit diagram? A simple 6 or 8 station control with adjustable timer ...
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3answers
1k views

Can a DC motor with obstructed movement be damaged?

I am trying to build shades, which should roll up or down, controlled by a DC motor. This motor can only be turned on or off (1/0 to turn it on/off). Also, it should be noted that the microcontroller ...
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3answers
438 views

Closed loop plant-control system

I have the next system, and I want to find the transfer function from d to y. So I've got the next equations $$v = Ce = C(r-y)$$ $$e = r - y$$ $$u = d + v$$ $$y = Pu = Pd + PCr - PCy$$ Now I know ...
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1answer
192 views

How to Design a State Feedback Controller using an algorithm

I'm studying for an exam and am having a great amount of difficulty wrapping my head around this as I have minimal electrical engineering background, and my notes are confusing. I have read a few ...
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5answers
14k views

How to implement a self tuning PID-like Controller

I am trying to write a micro-controller program for controlling temperature in a system with the following characteristics: output can only be On or Off, with fixed cycle frequencies (~2-10 per hour) ...
3
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1answer
2k views

Controling a regular residential 110V/15A circuit switch (or relay) from a PC

I am a software engineer by trade and also a rather skilled and well rounded (residential) builder with a special interest in wiring. I have rewired my entire two-unit house, panels included and seen ...
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1answer
675 views

Using Matlab to draw a step response graph

I've got the next transfer function: $$ \frac{\hat{\alpha}}{\hat{\alpha_{ref}}} =\frac{w_n^2}{s^2+2w_n \xi s+ w_n^2} $$ Now I want to draw a step response input at height of \$\alpha_{ref}\$, where \...
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1answer
359 views

Meaning of an arrow in the control scheme

I cannot understand what the arrow that goes through "internal model" block mean? how can I interpret what does it do? What is the difference from any other "normal" arrow? (source: cam.ac.uk)
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1answer
190 views

I want to find \$\frac{\hat{\theta}}{\hat{T}}\$

I have the following block diagram, and I want to find the transfer function \$\frac{\hat{\theta}}{\hat{T}}\$. I am not sure how to do this, I've got the rules of connection in a series or parallel, ...
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2answers
3k views

Dimmer to bulb control

I need to control a bulb of 220V, with different intensity light levels. I've an Arduino Uno Board, which receives a variable voltage from a Light-to-voltage converter (TSL12S) (Like a photoresistance)...
5
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1answer
467 views

Using impulse response to control the system

This post by Olin Lathrop is rather inspiring. The system response is the convolution of the control input with this impulse response, computed every control sample, which is every 500 ms in ...
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5answers
451 views

M.S. Math to Engineering Ph.D : Mathematics in Electrical Engineering [closed]

I have two Bachelor's degrees. One is electrical engineering and the other one is mathematics. I am studying mathematics (partial differential equations) in the graduate school (Master course) now. ...
2
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2answers
321 views

Block Diagrams with offset in control theory

I have an equation in the form $$y = mx+b$$. In block diagram form, I could draw this with a proportional gain block and a summer. I was wondering if there are some clever tricks where I can make ...
2
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1answer
305 views

Controlling temperature of a water bath with induction plate

I am thinking of building a sous-vide cooker using some kind of prebuild heater, controled via an AVR and temperature sensor like the LM35. There are a lot of references around using rice cookers, ...
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1answer
2k views

Conversion of PID controller components with state feedback into single transfer function and discrete state-space form

I've been wrestling with this problem for about a week now, as a part of a year-long project. We're designing a controller for a specific reactor based on a model. After looking at this for a while, I ...
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1answer
502 views

Self Balancing Robot using Computer Vision

I'm planning to implement a Self Balancing Robot which is usually implemented using a gyroscope sensor which gives feedback to the micro-controller to adjust the position with wheels. I'm looking into ...
5
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3answers
647 views

Help finding transfer function for root locus using Matlab

I'd like to pick \$k_d\$ using root locus method, but have problems deriving the necessary transfer function of the system presented below. Assume \$k_p\$ is fixed. The question originates from Randal ...
2
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1answer
1k views

Brushless motor controlled via current source math model

I'd like to model a brushless motor's (BLDC) dynamic response using Matlab. I'm controlling the motor by an Elesctonic Speed Controller (ESC). I'd like to derive a transfer function of such a circuit ...
3
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2answers
373 views

What are common control strategies for dosing pumps?

Dosing pumps means pumps that dose a specific amount with a high accuracy. In many process control scenarios, level gauges or flow meters are used (with low accuracy, at least in some cases), what ...
3
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2answers
2k views

digital PID controller implementation

I am trying to implement a PID controller in the z-domain. What I have done so far is found some values of \$K_p\$, \$K_i\$, and \$K_d\$ that work in the time domain. I have found some information ...
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1answer
673 views

Controlling a Motor for test bench

This is my 1st question here and I'm stumped... I spent all my EE classes on programming and ICs. When it comes to AC and motors, I feel worse than ignorant and spent all day trying to research where ...
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3answers
1k views

How to build a precise voltage controlled resistive heater?

I have been tasked to build a heater for an industrial application. The heater uses resistance to heat the liquid and the application needs very precise control of temperature (+/- 1 degree). Existing ...
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2answers
6k views

Measuring tiny voltage variation with Arduino ADC handing the rapid changes in control algo

I'm hoping I can get some advice, I have an industrial laser position sensor from SICK that outputs 0 to 10 volts. I used a voltage divider to scale it down to 0 to 5 volt range, and feeding that into ...
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1answer
3k views

How to realize these transfer functions as a circuit?

While I am well aware of some of the technique about implementing transfer functions I wanted some input about how can i realize this transfer function with active filters (OpAmps are preferred): 1) $...
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1answer
4k views

How I can set up a transfer function of y = mx+c?

I have a system governed by the following relationship: \$V_{OUT} = m * I_{IN} + 5\$ I need to write a transfer function for the equation. Would anyone please give me some suggestion of how to ...