Science topic

# Control Systems Engineering - Science topic

Control engineering or control systems engineering is the engineering discipline that applies control theory to design systems with desired behaviors.

Questions related to Control Systems Engineering

Hello, I have a PWM signal having a variable frequency. I need to remove high frequencies from PWM. For example, I want to stop frequencies above 20kHz and can pass frequencies below 20kHz. Any idea how to design this technique in MATLAB Simulink?

Thank

**Background:**

In control theory we often develop new methods for analysis or controller/observer/filter design and usually evaluate them with numerical simulations. In many papers only a few selected examples are considered.

I think it would be desirable, if there was a catalogue of potential example systems which contains a variety of system models from one could select those which are suitable for a specific use case. A colleague and I are working on such a catalogue (see https://ackrep.org for more information).

After establishing the framework, a basic ontology ("Ontology of Control Systems Engineering") and some preliminary examples (e.g. cart pole system, Brockett integrator, some PDEs and DAEs), we now look for more content. Another colleague recommended http://www.compleib.de/ which contains > 100 linear state space systems.

I am also aware of some other small collections of nonlinear/mechanical systems (available only as PDF file) such as :

Differential Flatness of Mechanical Control Systems: A Catalog of Prototype Systems, 1995 Murray, Rathinam, Sluis

**Question:**

Are you aware of other catalogues or collections of dynamical systems? Preferably, the equations (and potential metadata) are available in a machine actionable format, but this is optional.

I hope this message finds you'll well. My name is Onyero Walter Ofuzim. I am reaching out to express my interest in collaborating in the field of Electrical/Electronic Engineering mainly in Control Systems Engineering, Dynamic Networks, Machine Learning, IoT, and/or Robotics.

I am deeply passionate about these areas and have been actively involved in research and projects related to them. I firmly believe that collaborating with others in this field will not only increase my chances of getting into a foreign-funded Masters or Ph.D. program, which is my ultimate goal but also help drive innovation and advancements in the field.

I am eager to share my ideas and knowledge and learn from others to contribute to the growth and development of these cutting-edge technologies. I am confident that my skills and experience will be a valuable asset to any team, and I look forward to the opportunity to work with anyone who will be nice to have me.

Thank you for considering my request for collaboration. I look forward to hearing about a possible invitation.

Feel free to explore my profile as I am optimizing it to make my chances high.

**I admitted as an undergraduate to multiple universities in Arizona and Colorado!**I have been actively looking for admission to the university to continuously prepare me as an investigator/innovation scientist in mineral exploration by building my foundational knowledge in metallurgy, chemistry, control systems engineering, geochemistry, geophysics, etc. These might be included in my coursework. My focus may be on "control system engineering" compared to "geoscience," as I want to spend my effort investigating sensor innovation using metallurgy, geophysics, chemistry, etc. for mineral exploration. Precisely, investigative research will be on creating "detection technology for purposing of Mining exploration and extraction" So, I'm confused with two queries: 1. Which university would be the best option based on my research interests? 2. Which major and region for internship/ real time research job corresponds to what I'm actually looking for?

Hope you already understand I’ve applied many universities with getting rejection that didn’t also find exact research team yet I’m looking. Thank you so much.

With this question, I want to know that proper systems exist? or they are just theoretical systems?

How long does it take to a journal indexed in the "Emerging Sources Citation Index" get an Impact Factor? What is the future of journals indexed in Emerging Sources Citation Index?

In his name is the judge

Hi everyone

In order to use controller for structure with absorber, have to connect matlab and opensees in real time :

it means in each loop in opensees data must send to matlab and then matlab do some prossess with controller like fuzzy then send back data to opensees

Relying on researching and consulting the only way is use hybrid simulation (like openfresco),

do you have any other idea or way to connect these two programs without using openfresco?

Translation results

star_border

Consult

Wish you best.

Take refuge in the right.

I already saw some examples of GA (genetic algorithm) applications to tune PID parameters, but I (until now) don't know a way to define the bounds. The bounds are always presented in manuscripts, but they appear without great explanations. I suspect that they are obtained in empirical methods.

Could Anyone recommend me research?

As IEC 61131-3 standard for PLC programming languages defines a few of them, it will be useful to learn what our colleagues apply for PLC programming.

Does anyone know if I can connect the attached DAQ (CASSY type) to MATLAB real time simulink for controlling purposes?

Hi

How can i correct this error?? I think it's about matrix dimensions for port e.

Error in default port dimensions function of S-function 'FeedbackLinearization/Controller'. This function does not fully set the dimensions of output port 2

I'm running a simulation based on feedback linearization control method that comes from a paper attached below.

the model is also attached.

Anyone help me, helps a poor student. (if it makes sense lol)

Assuming that no motion in the normal direction, how would you propose a system of hardware and interconnection as well as the control strategy that will drive the system?

Suppose we have a lipschitz nonlinear system with a disturbance input. The disturbance is of decaying exponential like nature with an upper bound known.

System: x_dot = f(x) + g(x)u(t) + d(t)

where, x:state; u(t): control input; d(t): Disturbance input

How can we design nonlinear observer for such system?

Hi!

I have started working on a project "floating sensor networks (FSN) for continuous water quality monitoring". For which I need simulator to measure Like, pH, Turbidity, Salinity, Temperature, DO, EC, etc. Rather than going with real time deployment of FSN for measuring water quality sensors.

Objectives of the Project:

A. Water Quality Measurement

B. Reliable Data Transform

C. Congestion Control

D. Deployment Strategy

E. Energy Harvesting

All objectives should be carried out simulation based. Kindly suggest whether this work will done via simulation design (either partially or whole)

Thanks in Advance.

Hello everyone,

I'm looking for some short courses (not online) in the field of CE (more interested in Automotive control) in Europe.

My field of interests are,

- Robotic Control Systems

- Vehicular Dynamics Control

- Motion Control

- Data-Driven Control

- Optimal Control

- System Identification

- Reinforcement Learning Control Design.

I can participate by Self-Fund but I will be happier if there will be a scholarship or something,

please help me in this area if you have any experience,

Thanks a lot for reading,

Yours cordially,

A. M.

**We can avoid dq transformation by using PR controller. Why don't we use PR controller in industry? Why do we prefer PI controller?**

it means the oil pump to be sometimes able to turn off during the driving cycle, and if it is possible, how efficient would it be? (more particularly in heavy vehicles like a bus).

I am designing a flight controller for a quadrotor.

At first I am designing a nested/cascaded controller consisting of only proportional controllers K

_{p . }Now, if i tune the rate controller for 10 rad/s cross-over frequency, what should be the cross-over frequency for the angle, velocity and then the position loops. Also, what else do i need to know while designing a flight controller for practical implementation purposes?Secondly, How do we implement a own flight controller such as observer based via arducopter?

I am trying to discretize a continuous time state space model using the following code

s=tf('s');

G=1/(Iyy*(s^2))

Gs=ss(G)

Gd=c2d(Gs,0.01,'zoh');

Now, when i use this discretized model 'Discrete State-space Model' in simulink, my close loop system goes unstable. Same is happening with observer, like discretized observer is making close loop system unstable. Can someone help me here?

Optimal control and nonlinear control system.

Consider a system with relative degree two with respect to a chosen sliding output function s. If twisting controller is applied for control, what are the expected drawbacks in control performance and steady state behaviour? You may consider that $s$ and $\dot{s}$ is available.

PID controller is reportedly widely built and used in control systems engineering for industrial applications. The PID-controller has a transfer function as: (Kd*s^2+Kp*s+Ki)/s.

Therefore, it seems such a transfer function box, could be built in terms of an electronic circuit component.

Meanwhile, the order of an observer-based controller is higher than a PID-controller, as for example you see in the snap-shot from Ogata control engineering book, attached. Since Ogata is a practical engineering text-book, therefore I guess such an observer-based controller could be practically built as an electronic circuit and then embedded as a controller.

Moreover, we usually build transfer function blocks, simply in Matlab Simulink. But is it possible, practical, simple, and convenient to build such blocks as an integrated electronic element in a circuit, while they are of high order?

**My main question:**

There is a controller, with a transfer-function:

H_controller(s)=N(s)/D(s),

Where:

N(s)=b0*s^m+b1*s^(m-1)+b2*s^(m-2)+…+bm,

And:

D(s)=a0*s^n+a1*s^(n-1)+a2*s^(n-2)+…+an.

Moreover, m=10, n=10, or, n=11.

**The digested question:**

Is it possible, and practical to design an electronic circuitry for a box, with the transfer function: H_box=H_controller(s)=N(s)/D(s)

**?****Warning:**I have no experience to build a real electronic circuitry, and my question is only the possibility and practicality of designing a circuit for such a transfer function box. Do not mind about the performance of the controller or any other stability concern with regard to that. Only the possibility and practicality of designing an electronic box which has an equivalent transfer function: H_box=H_controller(s)=N(s)/D(s).

The box is in feed-forward path.

I want to know that we have a real system with fractional order state space model

I'm studying digital control by myself, and I would like to know if has available on the internet the solutions manual of "Digital Control of Dynamic System 3rd edition"?

For example, the first order Laplacian measures the difference between the local and average values of a quantity in an infinitesimal neighborhood of the point in question. So, for a flexible string, the acceleration is proportional to the Laplacian (wave equation).

For plates, the acceleration is proportional to the double Laplacian. Also, the double Laplacian occurs in the modification of the wave equation for a stiff string. Therefore, what is the double Laplacian a measure of? Thanks.

I only have acces to historical data recorded over the course of a few years. However the data is of a closedloop proces that has already been tuned with PID. The values of P, I and D are known.

How can I determine the openloop transferfunction usign only this data?

Why the results are not optimal?

difficult to infer all performance values? why

Is it theoretically possible, that after discretization by using Talyor Series Expansion, a non-observable nonlinear system will became an observable?

It was proved, that used continuous model of PMSM is non-observable (see attached). I want to know, if resulting discrete system is observable or not. Any comment appreciated. Thanks.

the dc-dc converters has two transfer functions , control to output and line to output TF. which one is used when design a controller? and which one is used to test step response?

How can I implant ANFIS as a controller in MATLAB/SIMULINK simulation for sit to stand movement supported with functional electrical stimulation in paraplegics. I think it will be inverse dynamic model and I should use model base controller

I'm a beginner in control engineer, what books or websites you could recommend?

Suppose a six degree of freedom simulation of an aircraft, which some aerodynamic parameters (e.g: stability derivatives), mass configuration (e.g center of mass) and etc, are randomly choose within known bounds. From the Monte Carlo sample those simulations are split in two groups: with instability (any time during the simulation) and without instability during the flight.

My question is, How could I find the more important combination of random parameters the caused the instability in flight?

I have already done a sensitivity analysis, so I have an idea how each one influence individually. What I really one to find is how the combination of parameter is causing the instability.

Hi every one,

here I have a problem in MATLAB, when I want to solve the following equation, relative to PI in the photo, or tau in the code, MATLAB will send me this error:

**Warning: Unable to find explicit solution. For options, see help**.I attached the question and the code below (in code, I rewrite pi in the photo with tau).

If you have any idea to solve this problem, analytically or numerically, I will be happy to hear it out.

*NOTE:*

*> PI_0.1(X,t) = tau*

*> X = [x(t),y(t),psi(t)]^T;*

**** PROBLEM: Find tau in terms of X and t in which solve the mentioned equation.**

Thanks in advance,

Arash.

**code:**

______________________________________

______________________________________

clc;clear;

syms x y psi tau t

c1 = 1;c2 = 1.5;lambda = 0.1;

x_r(tau) = 0.8486*tau - 0.6949;

y_r(tau) = 5.866*sin(0.1257*tau + pi);

psi_r(tau) = 0.7958*sin(0.1257*tau - pi/2);

x_r_dot = 0.8486;

y_r_dot(tau) = 0.7374*cos(0.1257*tau + pi);

psi_r_dot(tau) = 0.1*cos(0.1257*tau - pi/2);

phrase1 = c1/2*(cos(psi)*(x - x_r) + sin(psi)*(y - y_r))*(cos(psi)*x_r_dot + sin(psi)*y_r_dot);

phrase2 = c1/2*(-sin(psi)*(x - x_r) + cos(psi)*(y - y_r))*(-sin(psi)*x_r_dot+cos(psi)*y_r_dot);

phrase3 = 0.5*(psi - psi_r)*psi_r_dot;

eq = -2*(1-lambda)^2*(phrase1 + phrase2 + phrase3) - 2*lambda^2*(t - tau)

sol = solve(eq == 0 , tau , 'IgnoreAnalyticConstraints',1)

______________________________________

______________________________________

I want to know the exact definition of these four tests and I am wondering which of them could work in real time?

I have the nonlinear systems of Khalil, however some definitions are no so clear, is there a newer book with Matlab examples

Hello everybody

Despite a few TMD cost models available in the literature, I am searching for more accurate initial and lifetime cost models of translational TMDs for Life Cycle Cost Analysis (LCCA) of TMD-equipped structures.

In fact, the provided cost model affiliated with one of the companies designs and manufactures transitional TMD (such as LeMessurier CO.), which this model consists TMD initial cost (construction and installation of the TMD) and TMD damage cost (maintenance and repair losses of TMD before structural collapse)

I design feedback close loop system with a robust static feedback controller using Hinf approach where control low is u(t)=Kx(t). What is the good method to show robustness for this type of system? What plots we can make to show robustness for designed system?

Regards

Dear community,

I am trying to build a model of a Furuta pendulum in Simulink/Simscape. Unfortunately, when I try to linearize my model with the integrated Model Linearizer, I get an unexpected result. The evaluation of the linearized system shows, that it is only poorly controllable, although a classic Furuta pendulum should be fully controllable according to literature. Therefore I assume, that there must be something wrong with my model or the way I linearized it but I can´t figure out what it is....
I´d highly appreciate any help on that, as this is bothing me for quite some time now. The model is attached to this post. Furthermore I have attached a screenshot of the linearized system.

My controllability matrix (ctrb(A,B)) then looks like this with rank = 1, which I believe can´t be right...

Controllability matrix =

1.0e+26 *

0 0.0000 0.0000 -0.0000 0.0000

0.0000 0.0000 -0.0000 0.0000 -0.0007

0 0.0000 0.0000 -0.0000 0.0000

0.0000 0.0000 -0.0000 0.0000 -0.0015

0.0000 -0.0000 0.0000 -0.0000 9.2972

Thank you and best regards,
Joo

Hello everyone, I hope you have a good day,

As we all know, the lateral dynamic system of vehicles has two output, lateral error and heading error, and we have one input, which is steering angle, I always have one big problem:

**How to Design a Controller to have zero steady-state error, when I have XY reference path?**

I designed a controller to track the heading, but when the vehicle gets departed from the path, as it does not have any sense of lateral error, it will not come back to the path, it will just follow the heading with some offset.

I read a lot of papers in this area, but none of them talked about XY reference paths.

I add a photo to clear up some points, please check the attached file.

Thanks in advanced,

Arash

I'm writing my thesis and I am searching for good software to draw control block diagrams!

Any suggestion?

Thank you!

I want to find PID parameters to regulate my system.

I want to know all the things related and necessary which help me in control system field.

Hello everybody

I would like to link two topics, LCCA and BIM, each of which deals with "structural and earthquake engineering" and "construction management" in civil engineering, respectively.

I am trying to investigate on LCCA of a structure equipped with Tuned Mass Dampers (TMDs) based on principles of Performance Based Earthquake Engineering (PBDE) for different seismic hazard levels (this issue is related to structural engineering). So I intend to use BIM to create a more realistic cost model including other costs are related to this topic.

In order to get a better conditioned A matrix, the absolute mean of the eigenvalues of the A matrix should be one (all eigenvalues are between -1 and 1, so within the unit circle and the absolute mean is 0.4389). This could be done by scaling the time.

For the following continuous-time state-space model:

dx/dt = Ax(t) + Bu(t)

y = Cx(t)

the state-space model will look like:

dx/dtau = (1/lambda_avg)*Ax(tau/lambda_avg) + (1/lambda_avg)*Bu(tau/lambda_avg)

y = Cx(tau/lambda_avg)

with

lambda_avg, the absolute mean of the eigenvalues of the A matrix

tau, the new timescale

tau = lambda_avg*t

However, I want to scale the time of a discrete-time state-space model in order to get a better conditioned A matrix:

xi+1|k = Axi|k + Bui|k

yk = Cxk

How could I do that in the same way as for the continuous model?

Hello everybody,

I have observed a bit confusing behavior of my system response (or may be I am missing something).

I have a transfer function in S domain converted to Z domain with a 1kHz sampling frequency at the time of conversion using matlab, When I embed this discrete version of the transfer function to my system which is also sampling on the same frequency of 1kHz. The system works the way as expected (i.e. the step response is the same as that of the s-domain analogue controller).

But if I increase the sampling frequency of my system while using the

**SAME**discrete transfer function that i just converted from s to z domain with a SAME conversion sampling frequency of 1kHz , the step response gets further faster.My question is that, why the discrete system gets faster response than the analogue one, despite the transfer functions of the analogue controller and the discrete controller are the same.

What I understand, the step response of any transfer function should remain the same in either case (i.e. either the function is in s-domain or in z-domain) the response should be the same ?

Does this mean the digital controllers have the ability to fast the response of the same transfer function by changing the sampling frequency of the system?

**It is important, not to confuse the system sampling frequency of my u-controller at which the u-controller is collecting the samples from ADC, with the sampling frequency that I used as a parameter required to convert the s-domain transfer function to z-domain transfer function.**

I thank you all for your time.

Regards,

Iftikhar Abid

Would anyone help me to understand the difference between energy signals and power signals (with examples to each of them), and what is the physical intuition behind the relation between the auto-correlation function of a signal and its power spectrum density?

Thank you in advance.

I want to start to work on some stepper motors bipolar with arduino mega and ramps 1.4 but I don't know how to do it. Can anyone explain how to do this?

The specifications are in term of R, L, B, J, kv, kt

The max output force of electromechanical braking system is 3500N

What is the typical pitching speed of modern MW turbine blades and do this blades pitch fast enough compared to changing wind speeds?

I have a brushless gimbal motor (with 12N14P windings) whose rotor shaft position is measured by means of a high-resolution absolute optical encoder. (The motor has no hall-sensors)

The amount of current fed through the three field windings are independently controlled by 16-bit DACs. (i.e. not just PWM)

What control algorithm should be used to implement precise position control of this closed-loop system, and what auto-tuning technique should be employed?

I "think" that the 12N14P winding scheme means that one full rotation of the field winding signal produces one 1/14 of a mechanical rotation. (but I could be mistaken).

It is not known what the physical angular offset relationship is between the field windings inside the motor and the zero-datum of the absolute optical encoder attached to the rotor shaft. I suspect that the auto-tuning technique will need to perform an experiment to determine this angular offset if the control algorithm is to be able to produce a field vector that leads the desired position by 90 degrees to achieve maximum torque.

On what parameters the selection of continuation method depends ?

To design a controller for multi-degrees of freedom actuators which type of controller is better (Sliding Mode Controller or Backstepping Controller)?

Where can one get measurement data for ieee 34 bus radial distribution system ?

I am making a small prototype, that consist of small compact size aerostatic bearing with active compensation. I have to control eccentricity of shaft by using active compensation. For this purpose I need a laser sensor to measure shaft eccentricity that varies from 0 to 100um. one possible suggestion is to use laser sensor of omron company but problem is that my current location is china and omron company said it will take you 5 month to receive it. Please suggest me some other possible ways so that I can finish it before time

the coefficient of the plant should satisfy what kind of requirement ? and can you give some exampled?

Hi,

Does someone have any experience of using PSVM for fault detection?

Thank you for the information

Hello,

hoping that you will be in good health,

i have a 7-DOF independent wheel drive electric car model can be linear/nonlinear with longitudinal velocity, lateral velocity, yaw rate and angular rotation of the four wheels as the states of the system. the input to the system is the torque of each wheel .

i already designed a controller linear(LQR)/ nonlinear(SMC) which will turn the car with 90 degree yaw angle.

i want to find the trajectories/conditions that will achieve the control objective in minimum possible time/distance and minimum possible yaw rate, its kind of optimization "i think" can you please suggest any method or technique for doing this problem, or any starting point, i am using MATLAB/SIMULINK for my simulation ....

actually i am following the work done in this paper but they used some other tools for there work.

Dear all;

1: I used SVM to fault detection, now I want to figure out effect of fault in 10 seconds time slot of 60 seconds such that I have a window of data with 10 seconds length like 0-10 seconds,0.005s-10.005 s, 0.01s -10.01s ...60s. and I want to use SVM for each 10 s window of data.

I have some data in excel file which is divided to two parts; upper section is normal data and lower section is fault data and I have 6 features. Entirely I have 24002 data. I wrote a piece of code but I'm not sure if it is correct or not and I want to know how can I correct it? 2:I would like to know how can I divide my data to train and test in for loop for each window?

clc;clear;close all;

T=2001; %length of data in 10s (Window Size)

X=xlsread('Book4');

K=(0.5*length(X))-T+1 % Number of repetitions

window=zeros(2*T,6);

for i=1:K

window=[X(i:i+T-1);X(i+12001:i+12001+T-1,:)];

%% Data Normalaization

m=length(window);

Mean_data=repmat(mean(window),m,1);

Std_data=repmat(std(window),m,1);

data_norm=(window-Mean_data)./(Std_data);

end

I'll appreciate your help.

Sir,

I am unable to solve second ramp response. I need the derivation with partial fraction.

Thank you

OpenDSS is a wonderful package, but it is not suitable for simulating some special features of railway traction network, it would be fantastic to have something similar related to Railway power systems. What do you think?

I have designed a controller using Integrator backstepping method and that controller is based on Lyapunov Theory. I have a question How I can check stability of resulting controller?

I want to know if there is any system that needs to operate on different variants (combinations of the P, I, D constants) of PID controller; like it operates on P-only controller first; then switches to PI and then may be to PD or PID alternatively or simultaneously or may be cascaded? Is there any need to have such a system? If yes where and if not why not?

I want to ascertain the level of interaction in a MIMO process and I am looking at various ways of doing that. I came across the SVD method in the book by Seborg and I would like to know how efficient it is. Is the relative gain array (RGA) method better than this ?

P.S. - I am asking the question strictly from a control system perspective.

IMC BASED FRACTIONAL ORDER PID

all pole of the system are in left hand side of s -plane . But i m getting GM negative and phase margin(PM) as positive. Step response is also stable with 20 % overshoot and settling time as 6 sec. I m not able to conclude stability with tjhis results.

Please read this two pictures in File, It is in Chinese I took it from a paper but the symbol and expression is worldwide and international. For a system, select sliding mode valuable as S=c1e1+c2e2......en.

What if I want to know the value of S' (dot(s)) ? In this paper, It gives the expression of S'. It derives from the error state space by letting en'=xn'-dot^n(yd)=f(x)+bu-dot^n(yd), But can I get it in an easier way?

Let see, e1=x1-yd| yd is the reference signal and x1 is the output of the system,y=x1. e2=dot(e1),e3=dot(e2)=dot(dot(e1))......So, in this way, we can get the value of S and its higher order time differentiates. I think it may work and the final value we get should be the same numerically.

What's your opioions? Thank you very much!

If you agree with me, I have another doubt.

In the simulink model of that paper, It calculated dot(s) by that expression it gave, Why didn't it use differentiator to get dot(s)? It seems it doesn't want to introduce more differentiators into its system.

why every passive system can be considered as stable system.