So I did a full maintenance on my drivetrain and decided to also update my VESC’s to the newest FW at the same time. Also discovered that one of my phase wires was broken internally on my other motor, so I’m rolling single for the time being.
The FW update was something like from 3.x to 5.1, so a big update. I was very interested in testing the HFI to get my starts to be smoother and they are now in fact, excellent, so the HFI works great.
The only thing I haven’t been able to configure back in is the behavior of the full brake (short-circuit motor brake). The ERPM limit for full braking was nowhere to be found in the VESC tool, but I was able to configure it through the metr app, but the behavior is still a bit weird. When coming down to low speeds, it feels like the full brake gets applied for a moment, but as the speed lowers a bit more and HFI starts to run, it feels like the full brake gets released. So you slow down, get a little boost at a very slow speed and it then releases once fully stopped and I feel there should be a bit more resistance to rolling if the full brake was still applied.
So has anyone else come across this behavior or what settings to fiddle around with? Is it still possible to use full brake with HFI or is it just incompatible with it? Also why, if I don’t have reverse enabled, does HFI run if I’m at standstill and braking, I think/feel the HFI running essentially disables the full brake?
EDIT: Actually why is HFI even running, if my control mode is Current Control No Reverse Brake and I’m braking below the full brake ERPM limit, if it interferes with it. I understand that it would run if I wanted to drive the motors, but not during braking. I think this would be a good feature request.
Not sure why people really struggle with controlling their power in reverse, they manage fine when going forwards but for some reason the thought of having to manually control throttle in reverse shits them up.
@SimosMCmuffin current mode is super simple. forward throttle gives you forward acceleration, reverse throttle gives you backwards acceleration. This is always the same at any positive or negative speed. Anyonewho started on a boosted will be familiar with this.
It’s odd getting used to controlling your reverse power rather than just slamming on the breaks but once it clicks it feels very natural and obvious.
Current with hyst is basically the same but once you break you must come to a stop, release the break and reapply to get into reverse.
Just came to work on Current hyst, but even in the braking phase it still releases the brake once you are almost standstill, so you will start to roll up- or downhill faster than you were before when you were holding with the short-circuit brake.
I really liked the gummed up braking feel that you got with the short-circuit brake. Made it easier to stabilize the back-end, use it as a stable tilting point and hop the front to new direction. Now it’s more difficult if you try the same as the back-end will roll out from under you.
After testing that current mode, I suppose if I can’t have my full brake back with HFI, then this is the next best thing.
Need to tune the HFI settings a little bit. When going back and forth just constantly, it felt like sometimes the HFI lost tracking when starting to go forwards and the motor seemed to suddenly lock up or stuttered very strongly. Will test with lowered motor current first, in case it was the high motor current causing the HFI voltage to not be enough to keep tracking.
BTW, do the forward and reverse drive in Current Mode use the max motor current for both directions? Just feels like I have much less torque in the reverse direction, but it might just be my imagination.
AKA if i’m 100% acceleration in either forward or reverse direction (driving, not braking), will the motor get the max motor current (assuming not limited by battery current)?
