3 ms·
He stresses regularly spaced sampling. I don't see why high-precision timestamps wouldn't work just as well, though that would complicate the computation of th
by wnoise 9y ago
He stresses regularly spaced sampling. I don't see why high-precision timestamps wouldn't work just as well, though that would complicate the computation of the I and D signals.
Actually, throughout he doesn't seem to acknowledge the different units between the P, the I, and the D, instead implicitly treating the whole system as discrete time for many purposes, in e.g. the recommendations for 100:1 ratios between P, and I; and D and P.
- ebrewste 9y agoRegarding equal spacing: the sample rate determines a part of the system latency, and therefore performance and stability limitations. Eliminatating the stability of sample rate eliminates the decades of work basic controls analysis relies on. Or said another way, slow your sample rate and pay with your phase margin. Not to say it’s impossible to deal with (small) changes in sample rate, but in a text where he is already wildly simplifying things, this sounds like the wrong place to innovate.