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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Digital Control Engineering book recommendations [closed]

What are good books on digital control engineering specifically? I'm a third year electrical/computer engineering student who will be doing a course on digital control next semester, but would like to ...
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Step response to feedback loop with disturbance

When using step response to a feedback loop with disturbance. Why do we analyze the step response of the disturbance D and the step response of the input R separately. Instead of considering them ...
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677 views

Derive transfer function from block diagram

I have this block diagram which I already reduced pretty much: Now I want to derive the transfer function from phi_o1 to q. ...
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209 views

How can we find transfer function of this n/w

How can we find the transfer function $$\frac{E_0(s)}{E_1(s)}$$ of this RC network simulate this circuit – Schematic created using CircuitLab
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873 views

transfer function and error gain function

simulate this circuit – Schematic created using CircuitLab I know the difference between those two functions , but i want to see the relation between them , i think that the error gain function ...
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Is there any correlation between eigen functions and eigen vectors of an LTI system?

Eigen functions are the origin for Laplace transform while eigen vectors is for state space representation.Can we relate the eigen concept in these two? The complex exponential functions, are eigen ...
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677 views

Interfacing Matlab with a NI real time target (cRIO 9073)

I currently have a control system implemented in Matlab that controls a vehicle. The tracking is performed using an overhead camera, and commands are sent to the vehicle via xbee. I have now added a ...
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Control and transfer functions

I would like to determine the following transfer functions: $$T_1=\frac{y^\wedge}{d^\wedge}$$ $$T_2=\frac{y^\wedge}{r^\wedge}$$ $$T_3=\frac{e^\wedge}{d^\wedge}$$ $$T_4=\frac{e^\wedge}{r^\wedge}$$ In ...
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Controlling LEDs with multiple controllers [closed]

I have three black boxes each controlling an LED output. Each black box takes an input voltage and provides an output voltage (ranging from 0-12V) to illuminate the LED. Is it possible to alternate ...
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Switched Mode Power Supply : Voltage Mode Control and Error Amplifier Output

I am trying to understand how regulation happens on Cycle-Cycle basis in the case of Voltage Mode Control (VMC) and Current Mode Control (CMC). I understand that in the case of VMC, an error ...
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461 views

Overshoot control

Suppose I have the following step response: $$y_{step}(t)=\frac{kP}{1+kP}(1-e^{\frac{-t}{\tau}})$$ where k is constant and P is the plant. How may I determine the values of k for which there would be ...
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Pole-zero cancellation Paradox

Suppose we have an open-loop transfer function $$G(s) = \frac{1}{s(s+a)(s+b)}$$ If we plot the root locus for the closed-loop system we will get roughly something like this : Now the question is ...
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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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Does the use of PID controller require knowledge of plant's Transfer Function

As simple as that. I assume that you use PID when you do not know the Transfer Function of the system, otherwise you use it and plug it directly in the closed-loop control.
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PID gains from the transfer function of a plant

I am trying to calculate gains ( Kp, Ki, Kd ) of a PID controller. I have to improve the response of a plant. I already have the Transfer function of the plant. I was wondering if matlab has some ...
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What is Stiff Load?

In Control systems, when it comes to governer control, I came across with a term Stiff Load. Can someone please explain what it means?
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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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Can you implement a control algorithm and send the inputs via xbee?

I know this question is little bit vague, but let's say that I have a robot or a quadrotor to control. I want to implement the control algorithm (PID, robust, or LQR) in the PC not in the robot/quad, ...
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Affine Non Autonomous State Space system

Normally We all know the state space model of the the form der(x) = F*x(t)+G*u(t) y = H*x(t)+J*u(t). However I came across a state space model which has the following form der(x) = F*x(t)+G*u(t) + ...
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When is a programmable logical controller the best choice? [duplicate]

I am studying PLCs as a part of my Elements of Industrial Automation class. Trouble is, I can't imagine why would anyone use such a thing. For complex tasks, microcontrollers are available. The vast ...
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PD control (PID without I) - Homework help

I've been given a system - x" = bx′ + kx + ru and I've been asked to rewrite it in the canonical form x' = AX + BU. I've got -- ...
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133 views

Linearity and time invariance

If the input of an unknown system is shown by: \$x(t)= u(t)-u(t-1)\$ which results in the following output: \$y(t)=u(t)-u(t-3/2)\$ then what can be said about the linearity and time invariance of ...
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Difference between online PID and offline PID tuning?

I've been reading about PID control on the internet lately (Wikipedia). I came across the words 'online' and 'offline' in PID tuning. I googled it but couldn't find anything. What does this mean in ...
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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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1answer
886 views

how to make a system respond to IR laser? [closed]

Lets say i have 2 separate systems called Box A and Box B. Box A has an IR laser beam attached to it. What equipment can i use to make Box A make a certain action ONLY when the IR laser attached to ...
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Open loop vs closed loop in control theory

I have two questions: Why we study stability in open loop rather than closed loop (which is the system that will be implemented). and is there a relation between response time in closed loop & ...
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Control System - Changing damping on-the-fly?

I'm trying to implement a PID algorithm on a microcontroller that controls an actuator with a hard physical limit. In MATLAB, there's no consequence to large overshoots/hitting saturation at high ...
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Describing step response in terms of poles and zeros of transfer function?

me and a friend are stuck describing something, we're both coming to terms with using matlab and we're trying to understand the design of a simple control system for controlling the steady-state error ...
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Exclusive control over actuators

I feel kind of stupid asking this question, but after unsuccessfully searching for papers and then starting to draw my own solution with a lot of XORs to the following problem, I started wondering ...
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External programing of an mcu without Hex

We need to change a controller code from the out side as they do with industrial MCU. So that you have an MCU, with a program on it, and someone can program some "words" to it, that will determine how ...
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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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How should sampling frequency, switching frequency, control loop update frequency, and anti-aliasing filter corner frequency relate?

Suppose one is designing a processor-controlled switching supply. In general, how does one properly select switching frequency vs. control loop update frequency vs. feedback sampling frequency vs. ...
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375 views

Is impulse response always differentiation of unit step response of a system?

I was trying to solve a question in which the transfer function of a system was asked, its unit step response being given: $$ c(t) = 1 - 10^{-t} $$ The method that the book followed was to first ...
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Any open tool for graph plotting for determining PID tuning parameters?

I have gone through several PID implementations and its tuning tutorials, documents and all. The Best tuning tutorial was PID-without-a-PhD.pdf . But has not been of much help. I can say it works some....
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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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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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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)...
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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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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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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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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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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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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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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
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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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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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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
675 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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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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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 ...