You are here

Adding Openloop Com Comand and Temp. Measurement via Resistance

1 post / 0 new
JulianT
Offline
Last seen: 1 month 4 weeks ago
Joined: 2020-01-14 16:25
Posts: 6
Adding Openloop Com Comand and Temp. Measurement via Resistance

Hi.

This is a post from 2 Years ago in the general discussion but maybe it is better to post it here:

Is it possible to add a open loop comm command in the commands.c ? Like COMM_SET_OPEN_LOOP (Current, RPM)

As far as i know the open loop is already implemented and could be used in the new firmware in sensorless mode but i need it in sensored mode and i need to change the current value while running. To do this a UART command would be great.

I am building a 6 wheel car with 6 hub motors and the 6 esc s are controlled via uart / microcontroller. Turning at a point needs very high currents at low speed so it does not work with COMM_SET_RPM.  COMM_SET_POS works better but the movement is not smooth.

Temperature measurement via the internal DC resistance.
Advantage: You don't have to retrofit a temp sensor.
Disadvantage: only works when the engine is not running.
Because nearly every Motor has Copper windings and the change in resistance over temperature is more or less constant you just have to measure the resistance when you switch the ESC on or when you make the Setup. So when the motor is not turning the ESC can make a measurement again and than calculate the temperature. Of course it is not so accurate than a thermal probe but better than nothing.

Thx alot for an answer in advance and thx for this great project.

Kind regards

Julian Tacke