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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1answer
104 views

Circuit stable in the Bode diagram, unstable in step-response

I am designing a simple current control circuit and trying to simulate it in LT Spice. The circuit is not optimized for some real-world application, it's more a learning method for me to get grip on ...
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1answer
135 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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153 views

Mixed sensitivity controller design

I am defining a controller using the mixed sensitivity approach, and I have the following specifications: a low frequency attenuation of 60 dB a maximum resonance peak of 2 and I have chosen to use ...
2
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1answer
113 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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77 views

tracking error state space, linear control example

I am trying to understand a detail from an example, from the control textbook Slotine and Li (1991) "Applied Nonlinear Control", Prentice-Hall, Example 6.4, pag. 220. A linear system is given: $$\...
2
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1answer
250 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 ...
2
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0answers
68 views

Designing PID to reject load disturbances of dead-time process

I am using the PID Tuner for the PID Controller Block in Simulink. I am particularly interested in the output disturbance BODE plot. I am trying to achieve an acceptable output disturbance with the ...
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0answers
721 views

Deriving PI controller transfer function when input is reversed

I'm developing the compensator for the linear DC Bench Power Supply I'm designing. As I've come to deriving the transfer function for the op amp-based compensator, I realize I've been depending on a ...
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0answers
61 views

Closed-loop system with two cascaded P-controllers produces error increasing with time

The task: I control desired angle \$\theta_{d}\$ with two cascaded \$P\$-controllers, the outer is for desired angular velocity \$\omega_{d}\$ and the inner is for desired angular acceleration \$\dot{...
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1answer
72 views

Stability of SMPS designed for a motherboard

Many books have covered the stability of many configurations of switch mode power supplies and they have given details on how to set the poles and the zeros of the compensator to make the the power ...
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0answers
32 views

What is the meaning of the singular values?

I am studying MIMO control systems, and I have seen that the Bode plot of these systems is composed by the various singular values. But I have not clear the meaning of these sigular values. What I ...
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30 views

limitations on control effort

I am looking at loop shaping design of a control system, and I'm focusing my attention of the control effort. I have seen that it can be identified with a function called control sensitivity function ...
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0answers
70 views

Need help in designing control system

I tried to design the circuit but it doesn't give out the result that I was expecting and hope for and I am not sure why. Any idea on how to fix it? Original Transfer Function ^ Block Diagram ...
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0answers
35 views

Problem with performances of a control scheme

I am trying to prove with Matlab that if I have an improper system and I place poles at higher and higher frequencies the performances of the system improves. In particular I am considering the ...
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1answer
34 views

Layman explanation of “dynamics” or “dynamic behaviour”

I often read the term dynamics or dynamic behaviour in electrical engineering especially in control systems course What is meant by it? Is it means that the system whose internal state/properties ...
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0answers
57 views

Transient Response and s-plane root location

A second-order system has the closed-loop transfer function T(s)=Y(s)/R(s). The system specifications for a unit step input is as follows: I managed to solve the problem until this step. But I am ...
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0answers
43 views

Nonlinear Observer Question for BLDC

I'm looking at the article posted here, and I'm trying to figure out what it is that they're controlling and how. Specifically, Dave Wilson from TI gave a presentation called "Teaching Old Motors New ...
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35 views

Transfer function using signal flow graph problem

Determine the system transfer function for the following signal-flow diagram of figure I have shown my attempt of solving this problem. Can anyone tell me whether I did this problem properly?
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44 views

Stability of Buck Converter when output capacitance is variable

I am designing a buck converter for an application that has several different loads. Depending on what devices are connected, the capacitance seen at the output of the buck converter can vary ...
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0answers
24 views

Is it possible to predict the operating state of a power system (using MATLAB) if I have calculated the voltages at all nodes by state estimation?

If I have calculated all the node voltages by state estimation, is it possible to predict which operating state my system is at? By operating state, I mean any of the following: ...
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0answers
48 views

Controller for RC Filter

My class was asked to implement in MATLAB, a controller for an RC filter configuration with output response: 4/(s+3) The controller should give an output response whose steady state is 1 to unit ...
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0answers
125 views

CANopen SYNC object and synchronous window length

In CANopen specification there is an object called Communication Cycle Priod [1006h]. This is the time interval between two consecutive SYNC objects. There is also another object called Synchronous ...
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0answers
141 views

design a modular system, choosing bus and backplane

Our team has developed a several controller boards for our current Projects for over three years. With little modifications we have used this board in several projects so far. Its structure is as ...
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0answers
51 views

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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1answer
200 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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2answers
366 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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2answers
535 views

Transfer function of phase change controlled with capacitance

We have an RLC series circuit with sinusoidal voltage source of frequency \$\omega\$. The normal transfer function of current to voltage is: $$ G(s) = \frac{I(s)}{V(s)} = \frac{1}{R+s L+ \frac{1}{s C}}...
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63 views

Nonlinear system general representation

I am fairly new with non linear systems. I understand that a general representation of a nonlinear system is: $$ \dot{x} = f(x) + g(x)\cdot u $$ where \$x\$ is the state variable, and \$u\$ the input....
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1answer
62 views

The system is not completely reachable, Is state x1 reachable from x0?

The system is $$ x(k+1)=\begin{bmatrix} 1 & 1 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{bmatrix} x(k)+\begin{bmatrix} 0 \\ 1 \\ 1\end{bmatrix} u(k) \\ y(k) =\begin{...
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113 views

How to calculate the value of compensation network of DC DC converter

I am designing a circuit to boost voltage from 5V to 9V.I came across various kind of Switch regulator from TI. I don't know how to calculate the R-C value of compensation network. Thanks in Advance.
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197 views

Closed-loop systems - discrepancy between Simulink and Arduino

I am trying to figure out how to reproduce closed-loop systems in Arduino that were designed initially designed in Simulink. Take the following closed-loop system with unity feedback and gain: Where ...
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3answers
76 views

Does higher power wiring go higher in a control cabinet?

In looking for a image to answer an Industrial electronics layout and design question, I noticed that: within the cabinets, the higher power wiring seems to be at the top of the cabinet. Simply, the ...
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0answers
5k views

Determining closed loop transfer function from an open loop transfer function

I have an open loop transfer function given by \begin{equation} \frac{(s+3)}{s(s+1)(s+5)} \end{equation} I'm trying to convert it to a closed loop system with a gain of 0.987 and damping ratio of 0....
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0answers
83 views

Circuit diagram of the Full Order Observer

I am a novice in the field of control system and electronics per se. I am trying to implement the Full-order observer in an electrical circuit made of R, C and Op-amps. I understand the block ...
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0answers
157 views

LQR for inverted pendulum

I'm studying an optimal control for the inverted pendulum in the following figure the state and the output of the system are defined as $$x=\begin{bmatrix}r & \theta & \dot{r} & \dot{\...
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0answers
84 views

PI controller to drive a constant power source

So I have a load that needs constant power to maintain a specific temperature and this load changes over time. For this, I am using the design outlined in the following article: https://www....
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194 views

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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28 views

When do the positive sequence negative sequence, and zero sequence apprea?

I have analyzed three phases current in different cases, but I am still confused about some cases. Positive and Negative sequences are appeared but not the zero. Zero sequences is appeared, while ...
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1answer
40 views

Eddy current damping compensation

I have a magnetically permeable element (98% pure iron) vibrating at 3-5Hz between two electromagnets (with iron cores) which is experiencing too much damping, presumably due to eddy current losses. ...
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0answers
34 views

op amp stability theory

A little stuck and could use some help. This TI stability App Note on page 15 calculates the Thevenin equivalent circuit of a capacitively loaded op-amp and I can't figure out how they get that form ...
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0answers
188 views
+50

Problem in defining a generalized plant

I am trying to partially replicate this paper: Stability‐and performance‐robustness tradeoffs: MIMO mixed‐µ vs complex‐µ design I have to do a robustness analysis, and to do so I am first of all ...
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0answers
27 views

How to find the frequency responses for the below conditions in the eye model?

In the above image it says to calculate the steady state responses for a unit step response. But i need to find calculate the frequency response for the same model.
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38 views

use of DSP ICs in control systems

I'm doing a project on dc motor control. I heard somewhere DSP ICs are widely used in the aforementioned area. My question is about the advantage of using a DSP IC for implementing a PID loop for dc ...
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0answers
20 views

What does a peak in the complementary sensitivity function means?

I am studying control systems, and I am focusing on the concept of Sensitivity function and Complementary sensitivity function. I have seen that the sensitivity function is related to disturbance ...
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1answer
51 views

Digital Root Locus in Scilab

I have the following digital plant: \$G(z)=\cfrac{z+1}{(z-0.3)(z-1)}\$ I want to use root locus to design a system with: (1) position error=0; (2) overshoot \$\leq 10\%\$ (3) settling time \$\...
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1answer
22 views

Static and dynamic behaviour of a sensor

On a slide, i read that i can model the static behaviour of a sensor as: whereas it's dynamic behaviour as: Is correct to say that the static behaviour is the steady-state behaviour, while the ...
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0answers
21 views

Parameter range to ensure stability using Routh Criterion

I have a question regarding Routh Stability for a characteristic equation of the form, $$ 2S^4 + 2S^3 + 4S^2 + (k+1)S + 4 = 0 $$ I need to find the range of K for which the system will be stable. ...
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1answer
47 views

Obtain the matrix in a control system with tandem/cascade representation

I'm trying to find tandem/cascade and parallel realization for the following transfer function: $$G(s)=\frac{(s+6)^2}{(s+2)^2(s^2+4s+6)}$$ For Tandem/cascade realization, I draw the following block ...
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1answer
71 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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2answers
88 views

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 ...