Where does the formula for calculating torque come from?


I was wondering where the formula :arrow_down:️ comes from.


Cheers Stijn

The full formula is:

T = \frac{3}{2} \frac{1}{\sqrt{3}} \frac{60}{2\pi} \; \frac{I}{K_v}
  • Factor \frac{3}{2} is from the brushless motor torque equation (eqn 2.30 of this paper).
  • Factor \frac{1}{\sqrt{3}} is from converting line-line voltage (which is what is commonly used by hobby motor manufacturers in the determination of the Kv) to phase voltage (see here).
  • Factor \frac{2\pi}{60} is to convert from rpm to rad/s, which we need to do to get the torque constant from the voltage constant, due to the voltage constant being specified in units of RPM/V. (See here).

Thanks for the info

Cheers Stijn

Is the current I is Iq_measured in ODrive??