Hey! Post author here.
I appreciate the insight from someone who's worked on this kind of thing formally, thanks.
> Most likely what’s happening is that the creep torque is applying a constant small torque and the wheel sensors are reading 0 continuously, so it continues to apply a constant small torque.
This was also my hypothesis at the time of the post. Turned out it's less constrained than this, a fully operational car with the drive wheels off the ground will also run away to high rpm (even in Neutral): https://www.projectgus.com/2024/04/unremarkable/#on-car-test...
There's still minimal torque, as you say, so a small press on the car's brake pedal is all it takes to stop. However I think if a driveshaft broke on a real car then it'd be spinning fast for a minute or two... It kind of makes sense that the control loop is tuned for a heavy car with a fixed drive ratio, though.
I am still hopeful there will be a way to stop this behaviour via a control signal (rather than pulling the safety interlock and slamming the contactors open). Have left the problem aside until I have a mechanical brake to use for testing! If that doesn't work out then it's still usable I think, provided any EV conversion is single speed fixed gear just like the Kona.
If you have any other insights on this then I'd be very interested to hear them, though.
I appreciate the insight from someone who's worked on this kind of thing formally, thanks.
> Most likely what’s happening is that the creep torque is applying a constant small torque and the wheel sensors are reading 0 continuously, so it continues to apply a constant small torque.
This was also my hypothesis at the time of the post. Turned out it's less constrained than this, a fully operational car with the drive wheels off the ground will also run away to high rpm (even in Neutral): https://www.projectgus.com/2024/04/unremarkable/#on-car-test...
There's still minimal torque, as you say, so a small press on the car's brake pedal is all it takes to stop. However I think if a driveshaft broke on a real car then it'd be spinning fast for a minute or two... It kind of makes sense that the control loop is tuned for a heavy car with a fixed drive ratio, though.
I am still hopeful there will be a way to stop this behaviour via a control signal (rather than pulling the safety interlock and slamming the contactors open). Have left the problem aside until I have a mechanical brake to use for testing! If that doesn't work out then it's still usable I think, provided any EV conversion is single speed fixed gear just like the Kona.
If you have any other insights on this then I'd be very interested to hear them, though.