u/airconditioner26

Hi everyone,
I am working on a control system implemented on FPGA and trying to find resources regarding the topics in title.

Especially, I face some problems with defining data types and sizes. As an example, after discretizing a first order filter, I am confused which length of data types I have to use after a multiplication and summation inside the filter, as those are not necessarily physical variables that can be measured or interpreted. They are values between two stages of arithmetic operation inside the filter.

So I would like to learn more about basics on this. Also in general I want to learn more about registers, pipelining and resource allocation in control systems. So if you have learned and worked with such a system and know some resources (books, papers, youtube videos etc.) please let me know.
Thanks!

Note: Because of confidentiality I cannot tell more about the system to be controlled. You can imagine it as a spring damper with active damping implemented on fpga.

I just want to vent out a bit.

I go on social media (Insta, YouTube etc.) almost everyone is faking to be happy. Videos are fake, feelings are fake. There is nothing genuinely done. Everyone needs to post sth to get attention. Apart from that there are videos everywhere regarding immigrants and fights over who is native here and who came later. There is a rising extremisim around the world, even in the countries you would think of being democratic and humanist.

There is a rising economic crisis everywhere. You do not know if your pension will be enough when you get older.

Idk. It is just to much at once. Nothing excites me in life any more. Nothing is worth doing or interesting.I haven't imagined being adult like this.

Hallo in die Runde,
ich möchte kurz mal ein Realitätscheck über meine finanzielle Lage machen. Nämlich, ich bin 27M und arbeite als Ingenieur in Bayern. Ich habe irgendwie nur 10k Sparungen mit 65k Gehalt. Ich arbeite seit 2 Jahren und habe dazwischen meinen Job und meine Stadt gewechselt, wodurch enorme Kosten entstanden sind (bis zu 4k: Möbelkauf, Doppelmiete etc). Ich liebe meinen Job und gehe zur Arbeit mit Leidenschaft jeden Tag. Allerdings wenn ich mit anderen Personen spreche, kommt es immer so vor, als ob sie sehr viel mehr verdienen würden als ich und irgendwie immer in irgendwelchem Land im Urlaub sind. Ich höre auch von Arbeitskollegen, die eigenes Haus kaufen.

Bin ich wirklich in einem schlechten finanziellen Lage mit dem Profil oder ist bei euch auch ungefähr so?

Ich will natürlich auch mal mein eigenes Haus kaufen, wie das passieren wird weiß ich noch nicht. Bin von meiner Familie finanziell nie so gut unterstützt und habe bisher alles auf eigenen Beinen durchgezogen (Stipendien etc.). Wenn ich mal ein Auto kaufen will, wie das mit Sparung noch gehen wird weiß ich nicht.

Wegen meiner Erziehung, habe ich auch keine Luxus-Ausgaben tatsächlich. (Ich rauche nicht und trinke kein Alkohol, wodurch auch keine extra Kosten entstehen )

As the title says I think I am a people pleaser and a perfectionist. My perfectionism helped in ways and sometimes it is so exhausting but I think I can live with it.

But trying to please everyone while sacrificing my own worth is sth I cannot get rid of and also live with. As an example, I find it rude/unacceptable to ask for others to help me at work but when someone asks for my help or support I find it totally normal and be happy to be able to helpfull. It is like feeling your existence is 7/24 a burden for others. I do not suppose my brain has any benefit plans doing this (to be promoted, to get financial benefits etc.). I dont care about these things.

My understanding is I am seeking acknowledgment from surrounding. So being a likeable person guarantees that. To be likeable you are always there for others. So I basically do not love myself and care about my own ideas but others' view of me.

This insecurity also dramatically affects my romantic relationships.

Idk what I expect writing this. Maybe there is someone among you who got through same phases in life and got through it and can share how.

Hi!
If my open loop transfer functions passes through the 0 dB several times, which frequency is more important?

From my understanding in ideal case, we should consider WORST CASE scenario. That means, if at one crossover frequency the system has 5 degrees of Phase Margin and at another frequency 30 degrees, we take 5 degrees as PM.

BUT what if my system is not supposed to be driven with high frequency excitation where because of a resonance the open loop crosses the 0 dB again and thus the system becomes unstable?

I can ask LLMs and research in internet (have been doing already), but as usual, I am interested in views of different people here working in industry on real systems. Is my approach somewhat acceptable? At least for a first design phase of a controller for a mechanical system.

Have you ever dealt with nonminimum phase unstable systems? Especially in practice.
If so, what was your aproach to deal with such a problem?

I know that nonminum phase systems (without instability) has the restriction on the controller gain, as a high gain will eventuell drag the stable poles from the LHP to the instable zero positions on the RHP according to the Root Locus of the open loop transfer function.

More problematic is when the system is additionally unstable. And even more problematic when the RHP pole lies right to the RHP zeros. So untill you place a zero/pole after the RHP pole, that path remains within root locus path and thus instability is not compensated.

Is it sound, to draw such conclusions based on Root Locus only? Can a output feedback controller stabilize such a system somehow?

I personally see no other way than using a state feedback controller to shape the dynamics of the whole system by placing the eigenvalues in desired locations. Am I overseeing something minor maybe?

Would like to hear your experience with such systems.

As a phd student how do you deal with the anxiety "what if my idea is bullshit?". I am not talking about the idea of the whole dissertation, but rather small parts of it.

Speaking in a mathematical/modeling/CS concept, what are your steps dealing with a situation where you see this algorithm does not work as you expect. It is very interesting for me to see how different people approach this differently.

This was actually one of the reasons I did not want to do a phd's. This anxiety.

How do you get motivated to study, do sports or hobbies in the current phase of our world?
The older I got (30m), the more I realised how bad everyone is, how bad the politics is etc. I was a very motivated person back then and very successful in my education. But now nothing makes sense.
I think about doing sports or going after a hobby, and then realize at the end of the day, the world is such bad place, why does it matter. Idk, i am a bit overwhelmed to keep up with the flow and fake being motivated to live, work, study etc.

Hallo Zusammen,

seit einem Monat bin ich in meinem neuen Job. Es war quasi mein Traumjob und endlich fühle ich mich hier zugehörig. Allerdings, fast jeden Tag oder jeden zweiten Tag komme ich nach Hause mit einem negativen Gefühl von Unzufriedenheit (mit sich selbst).

Ich bekomme ein technisches Problem/Aufgabe auf der Arbeit, die ich lösen muss und bis ich diese löse fühle ich mich einfach dumm/wertlos. Am Ende löse ich das Problem irgendwie und ich und Kollegen werden zufrieden damit. Aber dann bekomme ich wieder eine technisch herausfordernde Aufgabe (weil das mein Job ist halt) und wieder fühle ich mich schlecht/dumm. Irgendwie denke ich je mehr Zeit ich für eine Aufgabe brauche desto dummer bin ich.

An sich beschwert sich niemand noch darüber, dass ich keine Leistungen bringe.

Liegt es daran, dass ich meine Fähigkeiten in der Probezeit nachweisen will oder an was anderem?

Wird es irgendwann stagnieren und man wird seine Ruhe haben wenn man nach Hause fährt?

Wenn einer meiner Kollegen etwas Zeit brauchen um eine Aufgabe zu lösen, denke ich persönlich nie negativ darüber und halte das für normal. Ich denke auch nicht dass diese Person dumm ist.

Ich habe generell durch das Leben immer wie ein Imposter gefühlt, der dies nicht verdient was er erzielt hatte.

Info: Mir ist Firma usw. egal. Es geht nur um meine innere Zufriedenheit mit mir selbst als Arbeitnehmer.