Tried FOC today, overall it felt very good, super smooth acceleration, here’s the log:
This is the first time I try it on dual and on hubs. I tried foc in the past with a single sensored and it was super good but I’ve never played with its settings much. On this one I seem to have a small intermittent issue with one of the two motors stuttering a bit when accelerating and braking hard.This issue at the motor (maybe phase wires, internal or probably related to the vesc) doesn’t affects BLDC and only a little bit FOC (it’s totally ridable as you can see) and I’ll probably spend some time and recheck everything soon: connections, VESC and motor wires, but for now I’ll just try to change the vesc settings and ride :D.
That’s how I configured the vescs - 2 attempts: first:
Detection succeeded smoothly, I tried to start the board from a stop with the default value of Observer gain (13.46) but I felt that it wasn’t very good, I used light stuttering of the motor as a test factor.
Second attempt, changed 1 value): I looked at the forum but then checked jacobbloy 's instructions for the VESC configuration in foc. On those there’s a suggestion by Ben to set Observer gain to 100. The board started much nicely with that. I checked the forum and I guess that I should try to up the motor max amps a bit because it feels a bit low for FOC (60A currenly)
I will switch from 60A to 75A/80A motor max and add 5A to brakes (motor min) as well, I’m also curious to try crazy values like 110A motor max because as I’ll probably never reach them and they should help against the current acceleration curve - I would like to try Ackmaniac’s firmware too soon so I can delegate this “fix” to the watt control mode instead of just brutally changing the max motor amp.
I would like to have more acceleration for starting quickly from a stop (after a push ofc), I missed that a bit on my first ride (good feature to have in urban environments), I believe that if the hubs were sensored this was not a problem.
Also I would like to change other foc related values (the one located in “FOC - General”, “FOC - Sensorless Startup” for example to improve the situation)
I also lowered the cutoffs which were pretty conservatives (32/30) to 30V start 28V even if I always fully charge my board before riding but this should prevent any cutoffs
Overall I can see/feel straight away that the acceleration is super smooth, hubs are silent, energy consumption seems less but I don’t know how much.
You can see from the log that I had a problem when testing hard braking on this one at 10:47 - https://metr.at/r/IcoKh - there’s a spike down during the deceleration even if I wasn’t braking 100%.
btw I love foc for now, hopefully I will have a video up soon, oops I wrote too much ^^