#robotics Logs

Jan 09 2021

02:30 AM sorki is now known as srk
08:00 AM sorki is now known as srk
06:26 PM rue_mohr: ok I have a servo, with a slew rate
06:26 PM rue_mohr: the slew rate determines the maximum bandwidth
06:27 PM rue_mohr: the idea is to hold the loop gain at 1 right up to that
06:27 PM rue_mohr: and its low-pass
06:27 PM rue_mohr: its first order (not quite sure how, but seems to be close enough, bit of overshoot)
06:31 PM rue_mohr: https://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Linkwitz_vs_Butterworth.svg/410px-Linkwitz_vs_Butterworth.svg.png
06:32 PM rue_mohr: https://en.wikipedia.org/wiki/Audio_crossover
06:35 PM rue_mohr: ok matching up the -3b points makes sense
06:38 PM rue_mohr: if I can simulate both high and low pass, I can play with it
06:39 PM rue_mohr: but if the sum of both the high and low pass are 50%, then the total should be 100
06:39 PM rue_mohr: I dont know if it would wiggle in the middle
06:39 PM rue_mohr: I need to get a working high pass simulation
06:40 PM rue_mohr: so, PID is actaully quite a mess
06:41 PM rue_mohr: its just a /\ gain factor you can apply to the system somewhere
06:41 PM rue_mohr: tho
06:41 PM rue_mohr: I suppose they cancel out
06:42 PM rue_mohr: there is no corner freq for a differentiator or integreator
06:42 PM rue_mohr: so the only control you have over the peak is by adjusting the gain
06:48 PM rue_mohr: I'm not sure how to code an integrator when there is no error signal
06:48 PM rue_mohr: maybe if you use the diff?
06:53 PM rue_mohr: wtf, no, thats a low pass with a pole
06:56 PM rue_mohr: I suppose an integrator natrually has a lot of gain