I am using the ODrive to control a hubmotor to drive a snow racer, just for fun. I’ve done some testing and see that I get the error DC_bus_overvoltage error. The ODrive is in torque mode.
As a user I don’t care if the torque is 5Nm or 5.5Nm. For any robotics application this is essential, but not for me, running around being silly on a way too small snow racer. When i push the accelerator I just want to increase the total power.
Is it possible to run the ODrive as a normal “ESC”? I have never seen a brake resistor on any other ESC. Also, I use the battery from an electric bike, and do not want to feed current back into it.
Any help is appreciated!
The energy has to go somewhere. Either it gets burned off in the resistor or it gets dumped back to the battery. It’s just physics, it has nothing to do with precision of torque commands.
What battery voltage and which ODrive are you using?
I’m using v3.6, 56v with the latest firmware. ESC’s for cars, planes etc do not have a brake resistor (afaik) so it shold be possible. If i command current equal to 5Nm and the current increases above this limit the controller in the ODrive would like to get rid of the energy to get to the desired setpoint. But for me it doesn’t matter. This is equivalent to a RC-plane with a spinning motor/propeller even if the input is zero. Some ESC’s feed the current back into the motor to brake the propeller and some just let the propeller spin freely. So instead of controlling the current/torque I guess I would like to control the duty-cycle (?). Does that make sense?
Again, the energy stored has to go somewhere. If a cheap ESC is just over-volting your battery, it doesn’t care and you probably don’t notice. ODrive both notices and cares
In electric cars (full size), you get reduced regen braking when your vehicle is charged near max because of this. Their “brake resistor” is a brake pad