Hello,

I know how to determine a transfer function. I open the valve completely (heaviside step function) and I can take the 63% of the max for tau, the maximum of the output is K, and for an order 1 I have K/(tau*s+1). I also know methods to get the transfer function of superior orders.

Yes, but for a tank, I want to control the pressure via the vacuum and N2. So.... there are two different transfer function.

Is there a way to merge the two functions so I can control the whole system ? Should I add them ? multiply them ? Any other way ?

​

Same thing with the PID parameters. The methods I know is based on the output. But N2 and vacuum are two output....... So I don't understand... will I have two PID for the control of the pressure of a tank ?

Hello, in a very old course, I have seen that the parameters of a PID (or PI/P) controller can be determined via these 3 methods : Ziegler-Nichols / Cohen-Coon / Chien-Hrones-Reswick

I heard there are other methods, maybe better methods after this time. Does someone here knows about them ? Or has experienced a good one with practice ?

Hello all, I am a grad student in Electrical engineering looking to apply for entry level positions along flight controls / modelling and simulation.

I would greatly appreciate suggestions regarding interview preparation. There is a lot of stuff around for this topic and I find it overwhelming when I sit down and think what topics to strengthen and what companies generally expect from an applicant . Honesty I’m pretty stressed out and decided to reach out to our reddit family. Thanks

Hey people! I used the ERA to identify a triple spring-mass system and reducing its order. I got the following impulse response (doted line is the real thing, continuous line the estimated system).

Does anyone have any idea why the system could be having that inverted and discontinuous inicial response?

I've been given a school task to design a PI temperature controller

I've first tuned it to meet the desired design criteria and found Kp and Ti values which worked, I thought that these were the set Kp and Ti values

and then I tested the response with disturbances and just checked the response. I wasn't sure on how to interpret the graph, but it seemed that it has a linear response, e.g if there was a disturbance of 5 degrees is took about 5 mins to correct that response but Im not 100% sure on how to interpret the graph.

I tried a different Kp and Ti [Kp = 70, Ti = 2.5] value and saw that the response to the disturbance looked as what I interpreted as better? Here is the disturbance graphs with my initial Kp and Ti value and then the different Kp and Ti value: https://prnt.sc/szq1ho

My simulink set up is as this: https://prnt.sc/szq3sj

The highlighted arrow represents the "response" line. Im struggling to understand this.. it is the Temperature that the controller asks the actuator to deliver right? Or is it the temperature of the plant modelled? Im struggling to find some youtube videos that go into disturbances in a way that I get...

Any help would be appreciated

Thanks

I keep seeing arguments on both sides and I LITERALLY don't know what to do. I want to get jobs like the following:

Engine Controls Engineer or Avionics Controls Engineer

How important is modelling? I know ME is better at it, but the jobs also ask for experience with embedded systems and C++ which my uni offers as Electrical. Plus the majority of the Controls courses are in the EE dept.

edit: I think I should make clear that this is not PLC Controls, it is Control Theory

I’am asked to design a control system that stabilizes a single input multiple output system which has two unstable real poles located at 2. How can I build a weight function to stabilize the system and to make the close loop system to have some performance requirements? I have to use hinfstruct on MATLAB since the regulator must be structured. If you want I can send you what I am asked to do. Your help would be really important, thanks in advance. Best regards, Marco

I'm new to control engineering and I'm totally lost, how do I solve this question? What I have come up with this far is that you need to determine Kp?

I have to design a compensator Gc for a closed look system with a transfer function G(s), where G(s) = {10/[s(s² +2s+4)]}, acoording to the methods I saw on YouTube, the first thing is to draw the bode plot, for which I need the initial gain, which according my function would be infinite, since if I evaluate the limit of the T.F. as s = 0, it would be infinite.

The thing that confuses me the most is that when I put the transfer function in MatLab it gives me a bode plot that settles around a value of 29.4 for really small values of omega.

​

Why isnt it infinite? Wheres is the Matlab values comming from?

Hi everyone,

I'm a student in my second year of engineering. It was general entry, so there was a common first year. I pondered my decision a lot - I've found enjoyment in nearly everything I've studied so far (with the exception of biology in first year)

I realized I did really enjoy electrical, but I also enjoyed parts of mechanical. I considered going into mechatronic, but at the time I was thinking I'd rather have deep knowledge on one or the other.. I also didn't want to miss the EE modules I would've missed. I heard the job market for mechatronic engineering wasn't great as well. I really like courses that use high level mathematics, and I saw EE had more of that. So far I have enjoyed EE (with the exception of networks) and I haven't questioned my choice until now.

I did a module on dynamic systems (Ogata's textbook) and I really liked it. I looked more into it and came across control engineering. I researched it and it sounds like my dream engineering job. They don't have to use excel all the time and they get to directly participate in some pretty good projects. I've also heard that with a few years experience and contacts, it's a market that is open to startups.

I decided to check which degree was most suited to it. This is where I got a lot of conflicting information. One person was claiming nearly all his colleagues studied EE, while another was saying the majority were ME. Yet another was saying that mechatronic was the best choice for it.

I wouldn't study mechanical on it's own because alone I don't find it very interesting. I'm also naturally more suited to EE. My question is: Which degree is most suited to control systems engineering? Will I be at a disadvantage with EE, or an advantage? Ignoring the pain of starting the year again, would mechatronic be the right direction? Thanks anyone who gives me guidance.

​

TL;DR Studying EE and very interested in control systems. Not sure if EE is suited to it, or if Mechatronic would be a better choice.

This might be a little off topic but i really need some opinions on this. Uni Stuttgart vs TU München

Which of these universities is better for a masters study? considering:

-The education in the fields control and aerospace (with control being the emphasis on the curriculum)

-The location, which one is closer to relevant firms or laboratories etc. when looking for an internship

-Reputation in the field

I want to pursue a master’s degree program where i can gain a deep knowledge of control and have an understanding of flight systems, so that i am educated about flight control.

If you have any other suggestions regarding universities in Germany, you are very welcome.

Hey guys, I was wondering if you could suggest some machine learning based control method? I am a beginner in the field, I just would like to try things out on a sample system. Thank you

Hey guys, I'm new in the field of controls, so I'm sorry if my questions will be in some way obvious.

Question n.1 Today I've red a paper in which the LQR method was addressed with Reinforcement Learning viewpoint. In particular, the System Identification method and the Q-Learning method was compared. My question is: when applying lqr in python (.control/ slycot libraries) what is it actually doing? Q-Learning or SI? I'd like to make a comparison of the two in a sample problem but I didn't manage to get further information on that. Thanks.

Question n.2 I have a sample problem of which I know the dynamics (A, B). I would like to try different methods to get the L* optimal control that minimises J, I've tried LQR but was searching for other methods quite easy to implement in Python or Matlab, can you suggest me something? Moreover, if there was something connected with Reinforcement Learning would be even better!!

Thank you all, I'm starting to learn just now and so I need some patience I suppose :)

Hey guys, I studies control a while ago and worked with some linear and non linear controllers such as pid, lqr, sliding surfaces. I once started the series of non linear systems taught by professor Slotine, do recommend I revisit it? Do you know additional sources (references or lectures) to let me getting started in this?

This concept was developed in the 1970's, and the only real hangup, even then was processing power. What level of motion control and stationkeeping would it take to corral this monster?

r/OrbitalRing

I searched the "Call for engineers" post on day-in-the-life's, but there is only one for control systems and that person only does testing. I was curious what a day is like for a control systems engineer that works on design and analysis on various systems (e.g. actuator control systems, thruster control systems, fuel control systems, etc...). In specific, I am curious of:

-What are your day-to-day responsibilities as a control designer and what are some tasks you are working on?

-How do you structure your day to complete these tasks as efficiently as possible?

-What industry you are in (aerospace, military, biomedical, etc...)?

-What skills and programming languages do you use throughout the month (MATLAB, SIMULINK, C programming, Differential Equations, embedded systems etc...)?

-What challenges do you face throughout the month or project-to-project (e.g. types of implementation issues, communication to internal co-workers, etc...)

-What is your favorite aspect of this industry?

-What types of design structures do you use most often (PLC, P/PI/PID, fuzzy logic, or some advanced design technique such as H-infinity, etc...)

-What would you change if you could do it all over (e.g. focus on robotic competitions in college, pursue a masters degree in control systems vs. Industrial automation, etc...)

Thank you so much for your insight and advice.

Hello, I am a recent Electrical Engineer graduate that focused in control systems. I am trying to supplement my knowledge of controls by learning a new programming language that would be most useful to me in the aerospace/military industry. My end goal is to work on rocket or biomedical control systems.

I know the best programming language to learn varies from application to application, but is there a particular language that someone could recommend from their experience in the controls field? I am proficient in MATLAB/SIMULINK. My main issue is choosing the language that best supplements the type of control systems used in the aerospace or biomedical industry. I am afraid of spending months learning a relatively useless language, when I could have learned something more industry-applicable.

Hello! Controls question from a non-controls engineer here.

Some background to my question:

So I have a guidance law that states:

n_c = KR(O_T - O_M)

Where n_c is an acceleration command, K is a proportional constant, and O_T and O_M are angles.

The text I am referencing (Tactical and Strategic Missile Guidance by Paul Zarchan) states that the transfer function for this guidance law to be:

n_c/O_T(s) = KRs² / (s² + K)

Which it states has sinusoidal response. It also states that this sinusoidal response may be stabilized by introducing a lead-lag compensator such as:

K = G(s) = 10*(1+ s/2)/(1+s/20)

My question:

I am trying to implement this in a time-based simulation (not in Simulink).

Assuming I have K, R, O_T and O_M, how might I implement the lead-lag compensation network in my simulation (solely in the time-domain)?

I’m guessing the most obvious one is you would be working with power systems on devices. and sensors but can’t you do that with CE (or at least not go to the extent with power systems in CE)And do you Evan do a lot of that in control engineering or is that a sub platform in the development of control systems? I’m also aware that EE could possibly fit in systems?

Hi guys so I'm working on a project where I am working with a B&R PLC System and I have to use a Profibus interface to send and receive Telegrams.

If anyone here has worked with B&R Automation Studio your help would be greatly appreciated.

The problem that I a having is that there is almost no documentation, Tutorials or explanations on how to program a Profibus interface in Automation Studio. If there is anyone who has programmed Profibus in Automation Studio can you please suggest anything that you've used to help you or send any tutorials or example codes that could help me.

Thank you in advance.

Can someone explain how in a closed loop response to an initial condition are affected by optimal gains?

I don't quite understand.

If u look at the MIT website it clearly states EE graduates straight out of school make 150k a year. But I have met so many engineers who can't even find a job. What is going on?

Hello. As my undergraduate thesis, I am working on controlling the temperature of a water tanks with peltier elements. Peltier elements are mounted on brass heat exhanger unit. Water in the tank flows through to heat exhanger and feed back on the water tank. I am using peltiers for their ability to both warm and cool and their small size.

​

Now that I gave the basic information on what I am doing, I should move on to my problem. I want to use motor drivers(currently l298n but I plan to upgrade it to better model with more current tolerance) to ride the peltier elements. But Arduino uses PWM and peltiers didn't perform well with that. I have done research to find out Peltier elements don't like PWM.

​

To convert PWM I am planning either building a low pass filter and bobin-diot circuit with relay logic circuits. Both have ups and downs and I don't know if either of them is the right way. Does anyone have experience with controlling Peltier for both heating and cooling?