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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 ...

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Meaning of transfer function in s evaluated at a complex number

From the pole-zero plot, you can compute the system frequency response by assuming a locus of test points along the \$j\omega\$ axis. Figure from: http://web.mit.edu/2.14/www/Handouts/PoleZero.pdf \...
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Nyquist Stability Criteria

Find the stability where: Find the stability: \$ G(s)= \frac{(s+3)(s+5)}{(s-2)(s-4)}; \$ \$ H(s)= 1; \$ I run this code in matlab: ...
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Normalization of Pid Output

New to using PIDs. When normalizing a range, we would need to know the maximum and minimum of that range. Since a PID is summing the error in the I portion wouldn't the range be potentially infinite? ...
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45 views

Designing of a PID Controller

First of all, I am new to this Q/A site. If I am doing anything wrong, please forgive me. I am having some trouble solving this problem: Given the system of Figure(1), design a PID controller so that ...
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52 views

How do integrator circuits serve as memory devices in continuous time system?

I didn't understand the yellow-marked sentence clearly, and even I did, what does it have to do with the conclusion that follows it? (marked in green). Thanks in advance.. Source: Modern control ...
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How to find a design parameter of backstepping controller for boost converter?

I have done project on control of boost converter using a backstepping controller. For that I use the PDF below: http://docsdrive.com/pdfs/medwelljournals/ijepe/2007/479-485.pdf But in paper I don't ...
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29 views

Control issues: Simulation of PMSM in FOC Model

I have been designing a model of an already existing actuator which is run in FOC with an SVPWM inverter and cascade speed-current control. Losses like eddy current or hysteresis, or switching losses ...
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Principle and generalization of proportional-resonance controller

simulate this circuit – Schematic created using CircuitLab We can introduce the model of \$u(s)\$ into the controller \$K(s)\$ to realize high accuracy control. \$u(t) = 1\$, i.e. \$u(s) = 1/...
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Finding PID parameters .. How?

As in the picture , how can I determine ki , kp , kd I tried (using provided data) by finding ζ and ωn But I end up with third order transfer function could not subsitute my results to find PID ...
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214 views

What is the relationship between a step input and an integrator?

While trying to understand control engineering from first principles I came across the following which I cannot yet explain intuitively or mathematically. What is the relationship, between a step ...
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31 views

Replacing Electrical System with a Gain?

I have a system containing both a mechanical and an electrical part, as shown in the block diagram below. I am interested in simplifying this block diagram by eliminating the electrical part and ...
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1answer
34 views

Pole placement to create a full-state feedback controller?

I am learning about control theory by going through Oagata's Modern Control Engineering. As part of a practice exercise I am trying to design a full-state feedback controller that satisfies my ...
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28 views

Determine the impulse response of the following discrete system

I'm not sure how they got the answer (provided below) for the following discrete system y[n] = x[n]- 2x[n-2]+ x[n-3]- 3x[n-4] the answer is given as .... h[n] = [1 0 -2 1 -3] why is this? any help ...
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What's a Singular point and an Ordinary point in relation to the Transfer Function of a Control System?

I am trying to Understand what an Ordinary point and a Singular point means with regards to the Transfer Function of Control Systems. I have not been able to see anything on the Web with an in depth ...
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45 views

Using Routh-Hurwitz Criterion to verify the feasibility of a system's design requirement?

The problem in question is as follows: Compute k, such that the roots of the equation s^3 + 10s^2 + ks + k = 0 have real part between -2 and -1.5. Justify your response using root locus AND the ...
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State Space Control of 3 DOF SISO MBK system

As part of a control systems course I have to implement control for a 3 DOF SISO mass spring damper model of a robotic cutter arm. The arm is to follow a 5Hz triangle wave reference which is ...
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1answer
79 views

Reducing the order of transfer function while maintaining same response

Scenario: I have been going through Ogata Modern Control Engineering book and working through several exercises to improve my understanding of basic control principles. I came across the following ...
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Clarke transformation for delta wiring

I find the transform to get alpha,beta and zero for Y wiring(image below), but didn`t find the transformation for delta wiring(Vab,Vbc,Vca). Someone know the tranformation for delta case?
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What is the meaning of the first gain in the block diagram?

I have do design a circuit based on the block diagram below. I know how to design the PID part but I don't understand what the K=2 is. For the PID I have made the following:
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38 views

Wire Single E-Stop To Multiple Safety Controllers

I have an E-Stop with 2NC contacts. Can I wire each contact in parallel to the redundant inputs of two different Safety Controllers? Does this reduce the Performance level or safety category as ...
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1answer
386 views

Finding the Transfer Function of Spring Mass Damper System

I have been going through Ogata Modern Control Engineering book and working through several exercises to improve my understanding of basic control principles. I came across the following example which ...
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25 views

Control system for matching purpose

Is there any best practice or model to design a control system aimed at verfying an input against a predefined answer?
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26 views

PID tuning for 2nd order system with zero pole

I have the following 2nd order system: I would like to add PID controller and to tune it. I read about Ziegler-Nichols tuning however I get weird results due to the zero pole since the result is ...
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1answer
51 views

Dynamic Compensator in Control Loop

Sorry if this has been asked previously, but I couldn't find anything here or elsewhere on Google (but maybe I'm searching the wrong terms). I'm trying to design a Type 2 compensator for a PWM chip I'...
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2answers
98 views

Source of poles and zeros in a physical system?

From where does the poles and zeros come into the transfer function of any system? And I am not looking for an answer in terms of mathematics but want to know what is there in any physical system that ...
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Calculating State Transition Matrix from CCF State Space Model

Given the state coefficient matrices for the state equation $$ \dot{x} = Ax + Bu $$ $$ A = \begin{bmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ -1 & -3 & -3 \\ \end{bmatrix} B = \...
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1answer
55 views

Calculating the transfer function of this op-amp circuit

The first op-amp is a differential, second one is a follower and third one is a second order low pass filter. I've been struggling with the low pass and the final output of the circuit and I am not ...
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1answer
60 views

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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1answer
149 views

Degenerate circuit concept and its theoretical and practical implications

I came across with the term "degenerate circuit" when I was studying solving linear differential equations with Laplace transform. I have learned that a system is called degenerate when the ...
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2answers
70 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
57 views

Control Theorie: Drawing Transition Matrix Trajectories

Given a transition matrix like e.g. $$ \phi(t)=\begin{bmatrix} e^{-3t} & 0 \\ 0 & e^{-3t} \end{bmatrix} $$ What is the analytical way of drawing x(t) for two given starting points? I only ...
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3answers
174 views

why do most sensors have an electrical output, regardless of the physical nature of the variable being measured [closed]

I have been trying to figure out a explanation to this question, can someone explain this ?
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1answer
61 views

Feedback Error Equation

I am currently digging into some amplifier feedback analysis tools papers and literature. I found some "term" right at beginning of this topic that I don't quite understand. That is "Error equation of ...
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28 views

Lag/Lead Compensation in CMFB for LVDS Driver

The question is regarding using the Lead/Lag compensation (RC circuit) in an LVDS Driver. In the circuit given in the picture, I have considered the Bond pad load to be the dominant pole. But now ...
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1answer
48 views

Method for selecting unique resistor values in all combinations

I do controls, and sometimes I want to monitor more dry contacts than I have digital inputs for. I'm cheap, and don't want to pay for more points, so sometimes I'll put some resistors in parallel ...
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47 views

Issues to create a current control transfer function for a DCDC Converter

I'm trying to reproduce a work I've seen in an article, but I'm encountering some issues. I used the data provided and the transfer functions placed by the author, but I did not get the same result, ...
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1answer
115 views

Field Oriented Control Feed Forward Term

I implemented a Field Oriented Control (FOC) controller for a synchronous motor, which works already pretty good. Now the I-part of the PI controllers is necessary to achieve a good reference tracking,...
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37 views

Using two motor drivers to control a single stepper motor

For this project, I am running a single, small (6mm di.) stepper motor. I require the full power available from the first driver to provide enough torque to rotate the motor’s gear. The problem is ...
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40 views

initial position detection in BLDC compressor

We have designed an inverter board to control BLDC compressor(air conditioner).The board is up and running.we are controlling(trapezoidal control) the compressor in open loop (without considering back ...
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1answer
51 views

Relationship between eigen values and state feedback

so lets suppose we have a state space model x[k+1] = Ax[k] + Bu[k] y[k] = Cx[k] + Bu[k] and we want to design a state feedback, assuming that the system is ...
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1answer
95 views

Discretizing a PID controller

I am discretizing the PID equation so we have this equation Now if we separate the integral term we get Applying backward euler method Now as we already have a differentiation , by applying ...
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1answer
45 views

Relation between dash pot and spring in forces when extracting a transfer function [closed]

If a spring load some energy and use it for opposing other forces, and a dash pot has a friction, physically the both shouldn't have the same force-displacement equation ? In most of dash pots, we ...
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2answers
323 views

Using mesh analysis to get the transfer function of electrical system

I am studying the book: Control system engineering for Norman S Nise. I left the college few years ago, and I forgot lots of thing about Kirchhof's laws (Voltage and current). I tried to solve the ...
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1answer
44 views

How to I go from generalized Transfer Function to generalized State Space, and back?

Question: How can I transform a generalized Transfer Function a generalized state space form (preferable with the First Companion Form), and back? For the sake of presenting an example, let us say ...
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2answers
293 views

How to determine the phase margin and transfer function of this bode plot?

I have some struggles to find the transfer function of this plot. We got the hint, that the "breaks" of slope can be assumed to be on vertical and horizontal lines. Also we should pay attention on the ...
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2answers
73 views

Meaning of the “pole” of a transfer function with time delay

I learned in basic control theory that we can determine the stability of an LTI system by the signs of the real part of the poles of its transfer function \$H(s)=\frac{N(s)}{D(s)}\$. For a rational ...
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4answers
173 views

PID Tuning Issue

I'm having issues tuning a PID controller - specifically the I-term. First - here's a little info about my system: I'm heating a coil (R ~= 1.8 Ohms) to 750°F. My power delivery system is working ...
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1answer
127 views

Solving the differential equation in control system engineering

While I am continuing my studies of the Norman S. Nise book about Control System Engineering, and while trying to solve exercises of chapter 1, I noticed that I am out of the scope of solving ...
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3answers
454 views

Block diagrams can be different and still works for the same system?

I am an telecommunications engineer who is working now as a programmer. At university we took a class on digital filters, Laplace transformation and working in the frequency and time domain. At the ...
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1answer
104 views

PID tuning without plant model

My aim is to keep temperature constant at a certain place. I don't have a mathematical model of the plant. Currently, PID is used with some fixed Kp, Ki, and Kd, and I want to optimize these ...