OVER_REGEN_CURRENT problem

1

Hi, I got some error after motor and encoder calibration. two 2804 motors with odrive V3.6 firmware 0.5.1. Please help to solve the errors.Thanks a lot.
Is there any configration mistake? BTW, I use a 12V mingwell power supply.

In [173]: odrv0.config.max_regen_current
Out[173]: 5.0

In [174]: odrv0.config.dc_max_negative_current
Out[174]: 0.0

In [175]: odrv0.config.brake_resistance
Out[175]: 0.4699999988079071

In [135]: odrv0.axis1.controller.config.control_mode = CONTROL_MODE_POSITION_CONTROL

In [136]: odrv0.axis0.controller.config.control_mode = CONTROL_MODE_POSITION_CONTROL

In [137]: odrv0.axis1.controller.config.vel_limit = 2

In [138]: odrv0.axis0.controller.config.vel_limit = 2

In [139]: odrv0.axis1.controller.config.pos_gain = 15

In [140]: odrv0.axis0.controller.config.pos_gain = 15

In [141]: odrv0.axis1.controller.config.vel_gain = 0.01

In [142]: odrv0.axis0.controller.config.vel_gain = 0.01

In [143]: odrv0.axis1.controller.config.vel_integrator_gain = 0.1

In [144]: odrv0.axis0.controller.config.vel_integrator_gain = 0.1

In [145]: odrv0.axis1.controller.config.input_mode = INPUT_MODE_TRAP_TRAJ

In [146]: odrv0.axis0.controller.config.input_mode = INPUT_MODE_TRAP_TRAJ

In [147]: odrv0.axis1.trap_traj.config.vel_limit = 2

In [148]: odrv0.axis0.trap_traj.config.vel_limit = 5

In [149]: odrv0.axis1.trap_traj.config.accel_limit = 2

In [150]: odrv0.axis0.trap_traj.config.accel_limit = 2

In [151]: odrv0.axis1.trap_traj.config.vel_limit = 5

In [152]: odrv0.axis1.trap_traj.config.decel_limit = 2

In [153]: odrv0.axis0.trap_traj.config.decel_limit = 2

In [154]: odrv0.save_configuration()

In [155]: odrv0.reboot()
Reconnected to ODrive 358A387A3335 as odrv0

In [156]: dump_errors(odrv0)
axis0
axis: no error
motor: no error
fet_thermistor: no error
motor_thermistor: no error
encoder: no error
controller: no error
axis1
axis: no error
motor: no error
fet_thermistor: no error
motor_thermistor: no error
encoder: no error
controller: no error

In [157]: odrv0.axis1.requested_state = AXIS_STATE_MOTOR_CALIBRATION

In [159]: odrv0.axis0.requested_state = AXIS_STATE_MOTOR_CALIBRATION

In [160]: odrv0.axis1.motor.config.phase_resistance
Out[160]: 4.987849712371826

In [161]: odrv0.axis0.motor.config.phase_resistance
Out[161]: 3.382427215576172

In [162]: odrv0.axis1.motor.config.phase_inductance
Out[162]: 0.0013441413175314665

In [163]: odrv0.axis0.motor.config.phase_inductance
Out[163]: 0.0009417851106263697

In [164]: odrv0.axis1.requested_state = AXIS_STATE_ENCODER_OFFSET_CALIBRATION

In [165]: odrv0.axis0.requested_state = AXIS_STATE_ENCODER_OFFSET_CALIBRATION

In [166]: odrv0.axis1.config.startup_encoder_offset_calibration = True

In [167]: odrv0.axis0.config.startup_encoder_offset_calibration = True

In [168]: odrv0.axis1.config.startup_closed_loop_control = True

In [169]: odrv0.axis0.config.startup_closed_loop_control = True

In [170]: odrv0.save_configuration()

In [171]: odrv0.reboot()
Reconnected to ODrive 358A387A3335 as odrv0

In [172]: dump_errors(odrv0)
axis0
axis: Error(s):
AXIS_ERROR_BRAKE_RESISTOR_DISARMED
AXIS_ERROR_MOTOR_DISARMED
motor: Error(s):
MOTOR_ERROR_DC_BUS_OVER_REGEN_CURRENT
fet_thermistor: no error
motor_thermistor: no error
encoder: no error
controller: no error
axis1
axis: Error(s):
AXIS_ERROR_INVALID_STATE
AXIS_ERROR_BRAKE_RESISTOR_DISARMED
motor: Error(s):
MOTOR_ERROR_DC_BUS_OVER_REGEN_CURRENT
fet_thermistor: no error
motor_thermistor: no error
encoder: no error
controller: no error

In [178]: odrv0.axis1.motor.error
Out[178]: 16384

In [179]: odrv0.axis1.error
Out[179]: 17

In [180]: odrv0.axis1.encoder.error
Out[180]: 0

In [181]: odrv0.axis1.motor.error
Out[181]: 16384

In [182]: odrv0.axis0.error
Out[182]: 304

In [183]: odrv0.axis0.encoder.error
Out[183]: 128

In [184]: odrv0.axis0.motor.error
Out[184]: 16384

2

The key error is BRAKE_RESISTOR_DISARMED – as of firmware 0.5.1 the brake resistor has to be explicitly enabled, so right now the current regenerated when the motors decelerate during calibration has nowhere to go. And dc_max_negative_current = 0.0 means the ODrive trips the instant any current flows back towards the supply.

Assuming you have the brake resistor physically connected, ensure you have:

odrv0.config.enable_brake_resistor = True
odrv0.config.max_regen_current = 0
odrv0.config.dc_max_negative_current = -0.01
odrv0.save_configuration()
odrv0.reboot()

Note max_regen_current = 5 was telling the ODrive it’s allowed to push 5A back into your Meanwell before using the resistor – those supplies can’t sink current, so leave it at 0 and let the resistor take everything.

Also, your last dump shows axis0 encoder error 128 = ABS_SPI_COM_FAIL – what encoders are you using, and how long are the SPI wires?

3

Thanks for reply, it is very helpful!
I try “odrv0.config.enable_brake_resistor = True”,but get below error info.
I use MT6701 encoder, add a STM32f103C8T6 as encoderbrige to transfer position reading (MT6701 can not be use directly with odrive?). SPI wires are 20cm long.

In [22]: odrv0.config.enable_brake_resistor = True

AttributeError Traceback (most recent call last)
File :1
----> 1 odrv0.config.enable_brake_resistor = True

File c:\users\thinkpad\appdata\local\programs\python\python39\lib\site-packages\fibre\remote_object.py:258, in RemoteObject.setattr(self, name, value)
256 object.getattribute(self, “dict”)[name] = value
257 else:
→ 258 raise AttributeError(“Attribute {} not found”.format(name))

AttributeError: Attribute enable_brake_resistor not found