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greenmachine11235 t1_j3rmb49 wrote

To emphasize this is not a new physical type of motor rather it's a new mathematical control model applied to the electronic control system controlling a DC motor.

The second point I question with this is the 22% stat. Given the emphasis on PID control I'm thinking they're 'typical' electric motor is one with a control system where they just give full continuous power which is not realistic, I don't think I've ever encountered a motor in any application without some form of control on it. Motors always slowly step up their voltage using PID or another control scheme, not doing so add huge stresses to parts and wastes energy so they're 22% is likely much much less when compared to real applications.

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ialsoagree t1_j3tac7l wrote

Further clarifying this is not a new control model.

PIDs were invented in the 1910s and implemented in the 1920s.

Today, VFD and servo controllers (what control most motors) come with PID controllers built in, and many can tune themselves.

This reminds me of the biologists that published a paper reinventing calculus.

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Lucky_Dragonfruit881 t1_j3tfcmi wrote

Out of curiosity, are you reading the headline, the news article written by an undergraduate Spanish major, the abstract of the paper, or the paper itself?

'Cause I'm looking at the guy's CV and it looks like he definitely knows his way around control systems

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ialsoagree t1_j3tjmip wrote

This is what the paper says in the abstract:

"A proportional-integral-differential (PID) controller converges the characteristically linear FV relationship of a DC motor to nonlinear Hill-type force outputs."

There doesn't seem to be anything new here. PIDs have existed for over a century. I've programmed PIDs and even more complicated control loops myself.

There's even more complex forms of PIDs like cascade controllers, where the output of one PID sets the setpoint for a second PID:

Inputs -> PID1 -> PID2 -> Output

Modern PLCs autotune PID loops for you. I've never seen an industrial motor controlled without an integrated PID loop, ever, in over a decade in the industry. Not one.

Edit:

Here's the Wikipedia link.

https://en.m.wikipedia.org/wiki/PID_controller

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Lucky_Dragonfruit881 t1_j3tlxhy wrote

I read the abstract. It also says

>In this study, we first construct an easily amendable, bioinspired electromagnetic motor which produces FV curves that mimic the Hill model of muscle with a high degree of accuracy.

It sounds like they built something, but motors are admittedly outside my area and I can't be bothered to log in for the full article.

Anyway, my point is that if you read the PIs publication list, there's a lot connected to control systems, so it seems premature to say "lol MDs discover the trapezoid rule," is more likely than "student journalist fails to write in-depth review of highly technical work. "

Edit: even if they're just demonstrating the relative optimality of the Hill curves, that's still publication worthy

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ialsoagree t1_j3tn59n wrote

What I quoted, follows what you quoted. It explains how they did it.

I'm not saying it is or isn't publication worthy, I'm saying it's not some new technology that you're going to see rolled out in the coming years. It's how DC motors have achieved over 90% efficiency decades ago.

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jenkinsleroi t1_j3th5v9 wrote

They're not claiming that they invented anything new about PID.

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thebeefbaron t1_j3sxay7 wrote

Came for this, thanks for vocalizing my frustration! It seems like they're cherry picking the worst case scenario for energy usage as a baseline to compare against.

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iLikeFunToo t1_j3tfwfd wrote

Yeah I’m still trying to understand what’s different about it. I get the power rate is adjusted to run in the most efficient range, I guess it does this by itself by slowing the speed when current is higher for heavier objects? Then you reduce BEMF while pushing higher current? Not sure what’s game changing about this or how it relates to muscles at all.

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BalrogPoop t1_j40dm04 wrote

This isn't even a new mathematical control model, I learnt to use PID control in my first year engineering papers and used it on literally this exact thing (driving DC motors).

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