High current at hall sensor calibrating

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1

Hello all,

High current flowing in motor when i want to calibrate hall sensor or motor calibration state.(20W - 14 pole - 2000rpm)
I tried several small motors for calibrating and they almost burned out.
If current_lim and current_lim_margin are low level then odrive can’t calibrate motor.

How can i calculate to current_lim and calib_max_voltage parameters ?

Thanks.

Odrive V3.6 - 0.5.4

2

Hi Selman,

You need to change calibration_current, resistance_calib_max_voltage, and calibration_lockin.current.

Here are the requirements:
calibration_current * 2 * motor’s phase resistance < resistance_calib_max_voltage
resistance_calib_max_voltage cannot be higher than 1/2 the supply voltage
resistance_calib_max_voltage should be as low as possible to ensure inductance calibration is successful (while still being greater than the calibration_current*2*motor_phase_resistance number)
calibration_lockin.current must be high enough to move the motor.

Can you please share the datasheet or part number of the motor?

3

It works . Thanks a lot.
phase resistance 1.34 ohm and inductance 1.34mH. 85kV. My design.

I have a another question. Cw and ccw currents are different(0.45A - 0.92 A) how can i set sensor angle ?
I changed to all sensor sequence but did not work (ABC-ACB, etc).

4

What exact calibrations are you running?

For hall sensors, you need to run:
AXIS_STATE_MOTOR_CALIBRATION
AXIS_STATE_ENCODER_HALL_POLARITY_CALIBRATION
AXIS_STATE_ENCODER_HALL_PHASE_CALIBRATION
AXIS_STATE_ENCODER_OFFSET_CALIBRATION

All in order. You can set relevant is_calibrated flags to true and save_configuration() to save the config for next power up.

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