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I'd definitely read a series about control theory. The first time round was very badly presented at my university. A lot of math, motivation hidden. Stuff like

I'd definitely read a series about control theory. The first time round was very badly presented at my university. A lot of math, motivation hidden. Stuff like Nyquist criterion just sort of appears out of nowhere as functions. I guess the big one is feedback being the magic, and then the complex plane tells you where that blows up.

pid-1 4y ago
I went down this rabbit hole in grad and my opinion is that Control Theory is good for writing academic papers, but has few applications besides the classical ones (mostly in mechanics). Techniques often need very strong assumptions about the systems being modeled, which severely limits their usefulness. In fact, CT is sort of the antitheses of the currently most hyped way of modeling systems: Machine Learning.
- jbay808 4y ago
  I hope I will be able to change your mind!
- alanbernstein 4y ago
  I think you're sweeping a ton of valuable applications under the rug by saying "few applications besides the classical ones" ?
- lagrange77 4y ago
  Interesting username for such an opinion. Also systems modeling is not the same as control theory. You could indeed utilize machine learning to model a system, which you could then control by classical controllers. On the other hand, control algorithms that use machine learning are a thing.
  - metaphor 4y ago
    > Interesting username for such an opinion. Perhaps just a coincidental namespace collision: Process ID, not Proportional-Integral-Derivative.
    - lagrange77 4y ago
      Yes, probably.
metaphor 4y ago
> Stuff like Nyquist criterion just sort of appears out of nowhere as functions. Black's canonical 1934 paper[1] Stabilized Feedback Amplifiers, which had an outsized influence on EE classical control theory, may have something to do with that: Results of experiments, however, seemed to indicate something more was involved and these matters were described to Mr. H. Nyquist, who developed a more general criterion for freedom from instability applicable to an amplifier having linear positive constants. ...which directly cites Nyquist's canonical 1932 paper[2] Regeneration Theory. [1] http://archive.org/details/bstj13-1-1 http://archive.org/details/bstj13-1-1 [2] http://archive.org/details/bstj11-1-126 http://archive.org/details/bstj11-1-126

pid-1 4y ago

I went down this rabbit hole in grad and my opinion is that Control Theory is good for writing academic papers, but has few applications besides the classical ones (mostly in mechanics). Techniques often need very strong assumptions about the systems being modeled, which severely limits their usefulness. In fact, CT is sort of the antitheses of the currently most hyped way of modeling systems: Machine Learning.

jbay808 4y ago
I hope I will be able to change your mind!
alanbernstein 4y ago
I think you're sweeping a ton of valuable applications under the rug by saying "few applications besides the classical ones" ?
lagrange77 4y ago
Interesting username for such an opinion. Also systems modeling is not the same as control theory. You could indeed utilize machine learning to model a system, which you could then control by classical controllers. On the other hand, control algorithms that use machine learning are a thing.
- metaphor 4y ago
  > Interesting username for such an opinion. Perhaps just a coincidental namespace collision: Process ID, not Proportional-Integral-Derivative.
  - lagrange77 4y ago
    Yes, probably.

metaphor 4y ago

> Stuff like Nyquist criterion just sort of appears out of nowhere as functions. Black's canonical 1934 paper[1] Stabilized Feedback Amplifiers, which had an outsized influence on EE classical control theory, may have something to do with that: Results of experiments, however, seemed to indicate something more was involved and these matters were described to Mr. H. Nyquist, who developed a more general criterion for freedom from instability applicable to an amplifier having linear positive constants. ...which directly cites Nyquist's canonical 1932 paper[2] Regeneration Theory. [1] http://archive.org/details/bstj13-1-1 http://archive.org/details/bstj13-1-1 [2] http://archive.org/details/bstj11-1-126 http://archive.org/details/bstj11-1-126