Sensorless Mode

A project log for ODrive - High performance motor control

Hobby brushless motors are incredibly cheap and powerful. However we need a way to make robots out of them. ODrive is that way.

Oskar WeiglOskar Weigl 08/04/2017 at 23:500 Comments

Quite a few of you have requested sensor-less operation: running the motor without an encoder. This is now a reality:

Video shows open-loop startup speed-ramp followed by switching to closed loop FOC velocity control.

The main limitation of this mode is that it's not able to provide precise control at very low speeds (it can however spin up to speed using not-so-precise control). Therefore, this mode is great for applications where the primary operational regime is at speed. So not great for CNC machines or polargraphs, but great for electric skateboards and conveyor belts.

If you are interested in the technical details, or have an ODrive and want to try this out, please see the Sensorless mode post on the forum for more detail.