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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6
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4answers
235 views

Gain margin and Phase Margin Physical Meaning

I have been trying to understand the physical concept of Gain and Phase Margin.From what I understand it a relative comparison around the critical point (-1,0) which when converted to magnitude and ...
2
votes
3answers
53 views

Is time-invariant system taking system initial state account?

The time-invariant system is defined as following: If y(t) = (H(x))(t) and y(t − τ ) = (H(x))(t− τ ) Then H is a time-invariant system. Has this definition taken system initial stats account? At t=0 ...
1
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3answers
112 views

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 – ...
0
votes
1answer
55 views

speed control loop for line following Robot

I am working to control the speed in my line following Robot (using arduino uno),by using proportional constant Kp in a closed loop, in my code I calculate the RPM from The Right Motor and the Left ...
2
votes
8answers
195 views

Why are there only PID controllers, no PIIIDDD (higher order) controllers?

Transfer function of a PID controller is: \$I\cdot s + P+\dfrac{D}{s}\$ Are there controllers like: \$A\cdot s^2 + B\cdot s + C+\dfrac{D}{s} + \dfrac{E}{s^2}\$ ? If so, are they common? Why do ...
0
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2answers
51 views

Control: what is the proper justification that you can't just make the output equal to the input if the system produces unstable output

Suppose we have a signal, it goes into the plant and generates an unstable response, a common question then arise at that point is why can't we just set our output to a "hard-coded" input. Think of ...
0
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1answer
32 views

Solenoid Valve for Selecting Between 2 Outputs

I'm looking for a solenoid (like) valve which will have 1 flow input, and which depending on the applied signal, will switch between 1 of 2 flow outputs. The electronic equivalent of what I'm ...
1
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2answers
30 views

Cascade Control System - Multi-Stage Temperature Control

I am new to the forum, hopefully you can help :) I am a software engineer trying to put together a control system. My controls background is not strong, I have really only tuned PID loops via trial ...
0
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2answers
60 views

how to map a pid controller to a process

How do you "map" the output of a PID controller to a process? Say you have a resistor, a thermometer, and a PID controller. The thermometer provides feedback, and the PID controller can control the ...
0
votes
1answer
67 views

So how do control engineers control nonlinear plant with exponential output?

Say that a system (circuit, pump, population model, etc.) has a exponential output of the type $$y = ae^{bx}$$ What do control engineers do in order to achieve control objectives such as tracking and ...
0
votes
1answer
48 views

Frequency dependency vs. memory effects [closed]

Is this the same? I would say no. On the other hand: Frequency dependent components (capacitors, inductors) store energy/information and hence introduce the memory. Also, smearing out of signals ...
1
vote
3answers
481 views

Exact definition of overshoot

I am a computational biologist and am working on some aspects of control theory in biological systems. Since control theory concepts are not well known among biologists, I need a good standard ...
0
votes
1answer
43 views

Sliding mode control

Please explain how sliding mode control algorithm works. I am working on fault tolerant controllers and I have been asked to implement SMC. I have tough time understanding it.
0
votes
2answers
57 views

control 2 outputs with a single input and pid

Overview I'm trying to levitate a constrained permanent magnet with 2 electromagnets. I'm having trouble conceptualizing the control system for such an operation. Setup The permanent magnet is ...
0
votes
1answer
38 views

Design Project via State Space

Design a state-variable feedback controller to yield a 20.8% overshoot and settling time of 4 seconds for a plant $$G(s) = \frac{(s+4)}{(s+1)(s+2)(s+5)}$$ I am studying Design Project via State ...
0
votes
0answers
18 views

What is pulse train filter in the context of a control system?

I have recently seen some code written in modelling tool like Simulink, ASCET which uses PT1 filter? Why do we use a pulse train filter? What is the difference between FIR, IIR, Chebyschev, ...
0
votes
0answers
45 views

Tuning rules for IT1 System

currently i am working on my Bachelor's Thesis. Its topic deals with finding the optimal parameters for a certain PID-Controler, which is used to control an IT1-System (to be more specific: a ship's ...
1
vote
2answers
74 views

Find system behavior: P or I type?

In control theory, how do I find out of which type a system is? P-type or I-type (P = proportional and I = integral) Consider the following nonlinear system with x as output: $$ \dot{x} = A(x) + Bu ...
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votes
1answer
42 views

Control systems Engineering [closed]

I am a third year student in Electrical Engineering, and I would like to get into Control systems. I was reading about the job ads and I noticed that I need to know PLC and HMI. I don't know if they ...
0
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0answers
22 views

Time independent sampled data systems

The following discussion I'm assuming that the plant has no dynamic component and is just a constant gain, with perhaps a one or two sample delay. The closed loop system can therefore be completely ...
14
votes
6answers
966 views

PID algorithm: how to account for fast input value changes after a long delay

I am trying to implement a basic PID algorithm on an Arduino Leonardo to mix hot and cold tap water using servo-controlled valves. The goal is to hold the temperature as close to a setpoint as ...
0
votes
1answer
50 views

Control Engineering: Model parameter estimation for a motor which will be under various loads

I am creating a closed loop controller for a motor which is part of a robotic arm. I give it a required angle, the controller calculates a control input, the motor moves, a pot feedbacks the angle, ...
1
vote
1answer
65 views

Design of PID control for a vibration exciter (shaker) without having the plant model

I want to design a PID controller for a shaker. But I don't have the system's differential equation or transfer function. I find the system identification algorithms complicated. Can I design a ...
1
vote
2answers
27 views

System identification on a non linear system

I am trying to estimate a transfer function for a pan - tilt unit. It's input parameter is a velocity, but it is constrained to move from 0∘ - 359∘ and the other way around. Saying in another way, it ...
0
votes
1answer
110 views

Remotely control power supply with adjustable voltage

I have a power supply unit with adjustable output voltage. The output voltage is adjusted using a potentiometer. However, I need to change output voltage remotely and dynamically. What kind of ...
1
vote
1answer
60 views

Control Engineering: Why are the Equation Error and Output Error different?

When modelling a system you must first estimate the form of the transfer function (order, time delay etc.), and then estimate the parameters (coefficients for the transfer function). A common way to ...
0
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0answers
27 views

Stablization of a $w$-system

I have the following system to be stabilized: \begin{equation} \begin{aligned}\dot{w}=Aw+Bv \\& A=\left( \begin{array}{ccc} 1 & 1 & 2 \\ 1 & 2 & 3 \\ 1 & 2 & 0 \\ ...
2
votes
1answer
169 views

State space modeling with disturbances using Matlab

I am doing a project which involves modeling a quadcopter in state space form using matlab. I first had to linearize the quadcopter equations of motion, and now have to implement them in a matlab ...
0
votes
1answer
183 views

MATLAB error: “acker” function not returning the same thing as ackermann's formula

I have a discrete time system Suppose I have the following AB matrix of my system $$A = \begin{bmatrix} 0 & 1 \\ 1 & 1.5 \\ \end{bmatrix} $$ $$B = \begin{bmatrix} 0 \\ 1 \\ ...
0
votes
1answer
110 views

Classic control theory - Negative gain required for a finite velocity error?

I have an assignment to design a control system with 2 degrees of freedom (Prefilter + Controller) to control a plant with the following transfer function: $$P(s)= \frac{2}{s(s-3)}$$ I am required to ...
0
votes
1answer
69 views

How to design a PID controller with no additional i) gain margin, ii) phase margin?

Given a system G(s), how do I design a controller C(s) such that no additional phase or gain margin is incurred? I would like to do this analytically Surely I could go through the step of drawing a ...
0
votes
1answer
98 views

Why does Nyquist plot only need loop gain but not the entire closed loop transfer function?

I was trying to compare a Bode plot and a Nyquist plot of the same system and realized that I was probably comparing apples to oranges Bode plot is plotting the entire closed loop transfer function, ...
0
votes
1answer
140 views

Help with building a 3 Phase DC Motor Controller

I'm looking to design the power stage of a 3 Phase DC Motor Controller for use with the Emrax 268 motor. The maximum input battery voltage would be no higher than 300VDC and the maximum continuous ...
0
votes
1answer
47 views

What is this process called: Analog input, with a analog output with setpoint

What is this process called: In my example the analog input represents line current. The analog output represents voltage. this is a closed loop with a target set point. The behavior would be that ...
2
votes
2answers
153 views

Why would Z/P cancellation with real part > 0 between the plant and the controller make the system unstable?

Can someone help me verify the claim if there is a zero pole cancellation with real part > 0 between controller Gc and plant Gp, then the system is not stable? I can't find any literature that ...
0
votes
2answers
67 views

What are some of the real life example of the so called “tracking and regulation” problem in control theory?

Given a plant, we need to design a controller that takes in an input r and then ensure that steady state error between the output and input goes to zero while the system remains stable. What is a ...
0
votes
2answers
192 views

Designing a PI controller for a first order system

I have a first order plant $$ b/(s + a) $$ That I'm trying to control using a PI controller $$ \frac{(K_ps + K_I)}{s} $$ I closed the loop with unity feedback to get this Transfer function ...
1
vote
1answer
183 views

Mathematical model of the temperature of resistors/heatsinks?

I want to model the transfer function of a resistor mathematically, and am after some resources / tips on if it's possible to do so. For example, if I put 1V into a 1 Ohm resistor, I want to know how ...
-1
votes
1answer
78 views

Lag compensator Design

I have system having unity feedback gain. Use a lag compensator to get 10% overshoot. settling time of 1sec. $$g(s) =\frac{0.1 s^2 + 0.7 s + 1}{s^3 + 6.98 s^2 + 9.86 s + 19.8}$$ Continuous-time ...
2
votes
2answers
250 views

How do electrical engineers actually apply control theory in real life?

I am currently taking a course in control theory. In control theory the system or impulse response is usually an algebraic expression in Laplace domain. Much of the work done in school is to find ...
1
vote
2answers
287 views

What does it mean to have a pole or zero at infinity?

what does it signify ? At pole/zero frequencies the response of a system goes to infinity/zero, so I think same is the case with poles/zeros at infinity, but how do these poles/zeros affect the design ...
1
vote
1answer
161 views

current control via microcontroller

I have a micro-controller which calculates and decides about the current each minute. Then for one minute the circuit must hold that current constant. Then it should control the current via a buck ...
0
votes
0answers
26 views

Averaging of state space equations for a multi input dc-dc converter

If I have a converter with one switch, then I can find the average state space matrices as A= kA1 + (1-k)A2 where A1 is matrix when switch is off and A2 when switch is off, k is duty cycle of the ...
2
votes
2answers
140 views

Stability of an unstable system using nonlinear element. Is it possible or not?

Say there is an system with open-loop transfer function $$G(s)=\frac{1}{s-1}$$ The system is definitely unstable. If I put an any nonlinear system in cascade with \$G(s)\$ & from the output, a ...
0
votes
0answers
34 views

Averaging of state space equations for a multi input dc-dc converter

If I have a converter with one switch, then I can find the average state space matrices as A= kA1 + (1-k)A2 where A1 is matrix when switch is off and A2 when switch is off, k is duty cycle of the ...
0
votes
2answers
286 views

Obtaining stability information from Bode plots

I am trying to understand the theory behind gain and phase margins from Bode Plots for systems with negative feedback, specifically this one: The transfer function for this system is: $$ ...
0
votes
1answer
97 views

Control theory: What is the physical interpretation of asymptotic stability

For Bounded Input, Bounded Output stability (BIBO), there is a very nice interpretation. All it means is that if for any finite signal the system produces a finite output signal, then the system ...
0
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0answers
89 views

Brushless DC motor or stepper motor for specific application

The specific application is for moving (or traversing) a carriage up and down a lead screw. The lead screw is rotated by a motor. Here is a rough idea: - Since 1996 a stepper motor has been used ...
1
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2answers
61 views

Control theory: What is the relationship between the number of elements in your system, and your diff'eq IO model and the dimension ABCD Matrix?

From my understanding, the order of your system is directly proportional to the number of elements in your system. Suppose I have a circuit containing 6 capitors/inductors Then the order of my ...
0
votes
0answers
54 views

implemented feedback loop to count pulses but loop doesn't work

I am implementing feedback loop which count number of pulses from optical encoder and convert it to rpm(speed). But i noticed that number of pulse count remains same irrrespect of the motor speed. I ...