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Comment by beambot | Hacker News Reader

Not only that... Classic controls (including PID, Routh-Hurwitz, root-locus, etc) are NOT taught in many graduate PhD controls programs!

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Those are undergrad courses. PhD should already know those by heart.

Not even for Masters in control programs. It's state space all day!

State-space is less relevant to regulatory and servo control loops (which is the majority of loops out there), and more of interest in advanced control systems.

Of course, in Masters programs, you are already expected to know basic PID control.

Graduate courses that cover PID control tend to focus on intricacies like loop pairing, RGA, etc. PID control is an eminently practical field of study, and has many interesting facets like bump transfers, split range control, etc. There's a lot to learn about PID control that is non-theoretical.

Are those topics no longer relevant to today's state of the art research?

It's possible that you're just expected to know them at that point.

Agreed. Many state of the art control strategies nowadays are based on optimization techniques (e.g. Model Predictive Control, MPC, optimizes a convex cost function of the state, setpoint and input to your system over a certain time horizon). This has become a viable control strategy for fast (>1kHz) processes only in the past 15 years, since the optimization can be computationally intensive.

Or be able to derive them. PID was never explicitly taught on my course, but all the theory behind it was.

Research? Largely no, although they crop up now and then in clever ways. They are still very relevant in industry, however.

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