Constant CURRENT_LIMIT_VIOLATIONs

Support
1

Hi, I have a new micro ODrive on a FingerTech FT1806 motor and an external SPI encoder. I keep getting CURRENT_LIMIT_VIOLATION errors even though I’ve put the current limits up really high. I’ve tried increasing the current_control_bandwidth and other items I’ve read about on the forum but no luck. I could really use some help.

I captured a triggering event using the webgui, I’ll see if I can post it here.
odrive_current_limit

I’ll also attach my current config - I have tried various settings changes but this is my latest. It doesn’t look like the current actually goes over my limits so I’m not sure why the error is triggered.

{
“axis0.commutation_mapper.config.approx_init_pos”: 0.0,
“axis0.commutation_mapper.config.approx_init_pos_valid”: false,
“axis0.commutation_mapper.config.circular_output_range”: 1.0,
“axis0.commutation_mapper.config.circular”: true,
“axis0.commutation_mapper.config.index_gpio”: 4,
“axis0.commutation_mapper.config.index_offset”: 0.0,
“axis0.commutation_mapper.config.index_offset_valid”: false,
“axis0.commutation_mapper.config.offset”: -2.5144221782684326,
“axis0.commutation_mapper.config.offset_valid”: true,
“axis0.commutation_mapper.config.passive_index_search”: false,
“axis0.commutation_mapper.config.scale”: 7.0,
“axis0.commutation_mapper.config.use_endstop”: false,
“axis0.commutation_mapper.config.use_index_gpio”: false,
“axis0.config.I_bus_hard_max”: Infinity,
“axis0.config.I_bus_hard_min”: -Infinity,
“axis0.config.I_bus_soft_max”: Infinity,
“axis0.config.I_bus_soft_min”: -Infinity,
“axis0.config.P_bus_soft_max”: Infinity,
“axis0.config.P_bus_soft_min”: -Infinity,
“axis0.config.calib_range”: 0.019999999552965164,
“axis0.config.calib_scan_distance”: 8.0,
“axis0.config.calib_scan_vel”: 2.0,
“axis0.config.commutation_encoder_bandwidth”: NaN,
“axis0.config.commutation_encoder”: 5,
“axis0.config.dir_gpio_pin”: 11,
“axis0.config.enable_error_gpio”: false,
“axis0.config.enable_step_dir”: false,
“axis0.config.enable_watchdog”: false,
“axis0.config.encoder_bandwidth”: 1000.0,
“axis0.config.error_gpio_pin”: 8,
“axis0.config.index_search_at_target_vel_only”: false,
“axis0.config.init_pos”: NaN,
“axis0.config.init_torque”: 0.0,
“axis0.config.init_vel”: 0.0,
“axis0.config.load_encoder”: 5,
“axis0.config.startup_closed_loop_control”: false,
“axis0.config.startup_encoder_index_search”: false,
“axis0.config.startup_encoder_offset_calibration”: false,
“axis0.config.startup_homing”: false,
“axis0.config.startup_max_wait_for_ready”: 3.0,
“axis0.config.startup_motor_calibration”: false,
“axis0.config.step_dir_always_on”: false,
“axis0.config.step_gpio_pin”: 10,
“axis0.config.torque_soft_max”: Infinity,
“axis0.config.torque_soft_min”: -Infinity,
“axis0.config.watchdog_timeout”: 0.0,
“axis0.config.anticogging.calib_bidirectional”: true,
“axis0.config.anticogging.calib_coarse_integrator_gain”: 10.0,
“axis0.config.anticogging.calib_coarse_tuning_duration”: 60.0,
“axis0.config.anticogging.calib_end_vel”: 0.15000000596046448,
“axis0.config.anticogging.calib_fine_dist_scale”: 1.0,
“axis0.config.anticogging.calib_fine_tuning_duration”: 120.0,
“axis0.config.anticogging.calib_start_vel”: 1.0,
“axis0.config.anticogging.enabled”: false,
“axis0.config.anticogging.max_torque”: 0.15000000596046448,
“axis0.config.calibration_lockin.accel”: 3.183098793029785,
“axis0.config.calibration_lockin.current”: 5.0,
“axis0.config.calibration_lockin.ramp_distance”: 0.5,
“axis0.config.calibration_lockin.ramp_time”: 0.4000000059604645,
“axis0.config.calibration_lockin.vel”: 6.36619758605957,
“axis0.config.can.bus_voltage_msg_rate_ms”: 0,
“axis0.config.can.encoder_msg_rate_ms”: 0,
“axis0.config.can.error_msg_rate_ms”: 0,
“axis0.config.can.heartbeat_msg_rate_ms”: 100,
“axis0.config.can.input_torque_scale”: 1000,
“axis0.config.can.input_vel_scale”: 1000,
“axis0.config.can.iq_msg_rate_ms”: 0,
“axis0.config.can.node_id”: 16,
“axis0.config.can.powers_msg_rate_ms”: 0,
“axis0.config.can.temperature_msg_rate_ms”: 0,
“axis0.config.can.torques_msg_rate_ms”: 0,
“axis0.config.can.version_msg_rate_ms”: 0,
“axis0.config.general_lockin.accel”: 20.0,
“axis0.config.general_lockin.current”: 3.0,
“axis0.config.general_lockin.finish_distance”: 100.0,
“axis0.config.general_lockin.finish_on_distance”: false,
“axis0.config.general_lockin.finish_on_vel”: false,
“axis0.config.general_lockin.initial_pos”: 0.0,
“axis0.config.general_lockin.ramp_distance”: 3.1415927410125732,
“axis0.config.general_lockin.ramp_time”: 0.4000000059604645,
“axis0.config.general_lockin.vel”: 40.0,
“axis0.config.motor.acim_autoflux_attack_gain”: 10.0,
“axis0.config.motor.acim_autoflux_decay_gain”: 1.0,
“axis0.config.motor.acim_autoflux_enable”: false,
“axis0.config.motor.acim_autoflux_min_Id”: 10.0,
“axis0.config.motor.acim_gain_min_flux”: 10.0,
“axis0.config.motor.acim_nominal_slip_vel”: 2.3399999141693115,
“axis0.config.motor.bEMF_FF_enable”: false,
“axis0.config.motor.calibration_current”: 3.0,
“axis0.config.motor.current_control_bandwidth”: 1500.0,
“axis0.config.motor.current_hard_max”: 100.0,
“axis0.config.motor.current_slew_rate_limit”: 10000.0,
“axis0.config.motor.current_soft_max”: 10.0,
“axis0.config.motor.direction”: 1.0,
“axis0.config.motor.ff_pm_flux_linkage”: 0.0,
“axis0.config.motor.ff_pm_flux_linkage_valid”: false,
“axis0.config.motor.fw_enable”: false,
“axis0.config.motor.fw_fb_bandwidth”: 500.0,
“axis0.config.motor.fw_mod_setpoint”: 0.6103333234786987,
“axis0.config.motor.motor_model_l_d”: 0.0,
“axis0.config.motor.motor_model_l_dq_valid”: false,
“axis0.config.motor.motor_model_l_q”: 0.0,
“axis0.config.motor.motor_type”: 0,
“axis0.config.motor.phase_inductance”: 2.354069692955818e-05,
“axis0.config.motor.phase_inductance_valid”: true,
“axis0.config.motor.phase_resistance”: 0.08217086642980576,
“axis0.config.motor.phase_resistance_valid”: true,
“axis0.config.motor.pole_pairs”: 7,
“axis0.config.motor.power_torque_report_filter_bandwidth”: 8000.0,
“axis0.config.motor.resistance_calib_max_voltage”: 1.0,
“axis0.config.motor.sensorless_observer_gain”: 1000.0,
“axis0.config.motor.sensorless_pll_bandwidth”: 1000.0,
“axis0.config.motor.sensorless_pm_flux_linkage”: 0.0,
“axis0.config.motor.sensorless_pm_flux_linkage_valid”: false,
“axis0.config.motor.torque_constant”: 0.0035956520587205887,
“axis0.config.motor.wL_FF_enable”: false,
“axis0.config.sensorless_ramp.accel”: 31.83098793029785,
“axis0.config.sensorless_ramp.current”: 3.0,
“axis0.config.sensorless_ramp.finish_distance”: 15.915493965148926,
“axis0.config.sensorless_ramp.finish_on_distance”: false,
“axis0.config.sensorless_ramp.finish_on_vel”: true,
“axis0.config.sensorless_ramp.initial_pos”: 0.0,
“axis0.config.sensorless_ramp.ramp_distance”: 0.5,
“axis0.config.sensorless_ramp.ramp_time”: 0.4000000059604645,
“axis0.config.sensorless_ramp.vel”: 63.6619758605957,
“axis0.controller.config.absolute_setpoints”: false,
“axis0.controller.config.circular_setpoint_range”: 1.0,
“axis0.controller.config.circular_setpoints”: false,
“axis0.controller.config.commutation_vel_scale”: 1.0,
“axis0.controller.config.control_mode”: 2,
“axis0.controller.config.enable_gain_scheduling”: false,
“axis0.controller.config.enable_overspeed_error”: true,
“axis0.controller.config.enable_torque_mode_vel_limit”: true,
“axis0.controller.config.enable_vel_limit”: true,
“axis0.controller.config.gain_scheduling_width”: 0.0010000000474974513,
“axis0.controller.config.homing_speed”: 0.25,
“axis0.controller.config.inertia”: 0.0,
“axis0.controller.config.input_filter_bandwidth”: 20.0,
“axis0.controller.config.input_mode”: 2,
“axis0.controller.config.pos_gain”: 20.0,
“axis0.controller.config.spinout_electrical_power_bandwidth”: 20.0,
“axis0.controller.config.spinout_electrical_power_threshold”: 10.0,
“axis0.controller.config.spinout_mechanical_power_bandwidth”: 20.0,
“axis0.controller.config.spinout_mechanical_power_threshold”: -10.0,
“axis0.controller.config.steps_per_circular_range”: 1024,
“axis0.controller.config.torque_ramp_rate”: 0.009999999776482582,
“axis0.controller.config.use_commutation_vel”: false,
“axis0.controller.config.use_load_encoder_for_commutation_vel”: false,
“axis0.controller.config.vel_gain”: 0.0010000000474974513,
“axis0.controller.config.vel_integrator_gain”: 0.0,
“axis0.controller.config.vel_integrator_limit”: Infinity,
“axis0.controller.config.vel_limit”: 50.0,
“axis0.controller.config.vel_limit_tolerance”: 10.0,
“axis0.controller.config.vel_ramp_rate”: 75.0,
“axis0.enable_pin.config.debounce_ms”: 50,
“axis0.enable_pin.config.enabled”: false,
“axis0.enable_pin.config.gpio_num”: 65535,
“axis0.enable_pin.config.is_active_high”: false,
“axis0.enable_pin.config.offset”: 0.0,
“axis0.interpolator.config.dynamic”: true,
“axis0.max_endstop.config.debounce_ms”: 50,
“axis0.max_endstop.config.enabled”: false,
“axis0.max_endstop.config.gpio_num”: 0,
“axis0.max_endstop.config.is_active_high”: false,
“axis0.max_endstop.config.offset”: 0.0,
“axis0.mechanical_brake.config.gpio_num”: 0,
“axis0.mechanical_brake.config.is_active_low”: true,
“axis0.min_endstop.config.debounce_ms”: 50,
“axis0.min_endstop.config.enabled”: false,
“axis0.min_endstop.config.gpio_num”: 0,
“axis0.min_endstop.config.is_active_high”: false,
“axis0.min_endstop.config.offset”: 0.0,
“axis0.motor.motor_thermistor.config.beta”: 0.0,
“axis0.motor.motor_thermistor.config.enabled”: false,
“axis0.motor.motor_thermistor.config.gpio_pin”: 1,
“axis0.motor.motor_thermistor.config.r_ref”: 0.0,
“axis0.motor.motor_thermistor.config.t_ref”: 25.0,
“axis0.motor.motor_thermistor.config.temp_limit_lower”: 100.0,
“axis0.motor.motor_thermistor.config.temp_limit_upper”: 120.0,
“axis0.pos_vel_mapper.config.approx_init_pos”: 0.0,
“axis0.pos_vel_mapper.config.approx_init_pos_valid”: false,
“axis0.pos_vel_mapper.config.circular_output_range”: 1.0,
“axis0.pos_vel_mapper.config.circular”: false,
“axis0.pos_vel_mapper.config.index_gpio”: 4,
“axis0.pos_vel_mapper.config.index_offset”: 0.0,
“axis0.pos_vel_mapper.config.index_offset_valid”: false,
“axis0.pos_vel_mapper.config.offset”: 0.0,
“axis0.pos_vel_mapper.config.offset_valid”: false,
“axis0.pos_vel_mapper.config.passive_index_search”: false,
“axis0.pos_vel_mapper.config.scale”: 1.0,
“axis0.pos_vel_mapper.config.use_endstop”: false,
“axis0.pos_vel_mapper.config.use_index_gpio”: false,
“axis0.trap_traj.config.accel_limit”: 75.0,
“axis0.trap_traj.config.decel_limit”: 0.5,
“axis0.trap_traj.config.vel_limit”: 2.0,
“can.config.baud_rate”: 250000,
“can.config.data_baud_rate”: 10000000,
“can.config.protocol”: 1,
“can.config.tx_brs”: 0,
“config.dc_bus_overvoltage_trip_level”: 15.0,
“config.dc_bus_undervoltage_trip_level”: 6.0,
“config.dc_max_negative_current”: -Infinity,
“config.dc_max_positive_current”: Infinity,
“config.enable_uart_a”: false,
“config.gpio0_mode”: 17,
“config.gpio1_mode”: 17,
“config.gpio2_mode”: 17,
“config.gpio3_mode”: 17,
“config.gpio4_mode”: 17,
“config.gpio5_mode”: 17,
“config.gpio6_mode”: 17,
“config.gpio7_mode”: 17,
“config.max_regen_current”: 0.0,
“config.uart0_protocol”: 3,
“config.uart_a_baudrate”: 115200,
“config.usb_cdc_protocol”: 3,
“config.user_config_0”: 0,
“config.user_config_1”: 0,
“config.user_config_2”: 0,
“config.user_config_3”: 0,
“config.user_config_4”: 0,
“config.user_config_5”: 0,
“config.user_config_6”: 0,
“config.user_config_7”: 0,
“config.gpio5_analog_mapping.endpoint”: null,
“config.gpio5_analog_mapping.max”: 0.0,
“config.gpio5_analog_mapping.min”: 0.0,
“config.gpio6_analog_mapping.endpoint”: null,
“config.gpio6_analog_mapping.max”: 0.0,
“config.gpio6_analog_mapping.min”: 0.0,
“config.inverter0.current_hard_max”: 7.900000095367432,
“config.inverter0.current_soft_max”: 7.0,
“config.inverter0.drv_config”: 5913173802956800,
“config.inverter0.mod_magn_max”: 0.6781481504440308,
“config.inverter0.shunt_conductance”: 1.0,
“config.inverter0.temp_limit_lower”: 135.0,
“config.inverter0.temp_limit_upper”: 145.0,
“hall_encoder0.config.edge0”: NaN,
“hall_encoder0.config.edge1”: NaN,
“hall_encoder0.config.edge2”: NaN,
“hall_encoder0.config.edge3”: NaN,
“hall_encoder0.config.edge4”: NaN,
“hall_encoder0.config.edge5”: NaN,
“hall_encoder0.config.edges_calibrated”: false,
“hall_encoder0.config.enabled”: false,
“hall_encoder0.config.hall_polarity_calibrated”: false,
“hall_encoder0.config.hall_polarity”: 0,
“hall_encoder0.config.ignore_illegal_hall_state”: false,
“inc_encoder0.config.cpr”: 8192,
“inc_encoder0.config.enabled”: false,
“spi_encoder0.config.baudrate”: 1687500,
“spi_encoder0.config.biss_c_bits”: 18,
“spi_encoder0.config.delay”: 0.0,
“spi_encoder0.config.max_error_rate”: 0.004999999888241291,
“spi_encoder0.config.mode”: 5,
“spi_encoder0.config.ncs_gpio”: 0,
“spi_encoder1.config.baudrate”: 1687500,
“spi_encoder1.config.biss_c_bits”: 18,
“spi_encoder1.config.delay”: 0.0,
“spi_encoder1.config.max_error_rate”: 0.004999999888241291,
“spi_encoder1.config.mode”: 0,
“spi_encoder1.config.ncs_gpio”: 0
}

2

I should mention I get the error both when doing velocity control and torque control.

3

Thanks for the comprehensive info! Looks like the current soft max is set to above the ODrive’s internal current limit – it’ll self-limit to a safe point of 7A, but there’s likely not enough margin to catch current spikes before they exceed the absolute maximum trip current limit of 7.9A. I’d recommend setting axis0.config.motor.current_soft_max to 5A or so and seeing if that helps.

4

Thanks for the quick reply. Turning current_soft_max down helped a lot.

There’s a bit of a balance I have to make between turning it down to avoid the current limit error and making the system under powered, maybe I’m near the limit of what the setup can handle. I think I’m close to an acceptable configuration now.

This is a great product by the way, nice work!

5

Totally understood - you should be able to slim down the margins with those feedforwards and the current / encoder bandwidths.

Glad to hear it’s working out for you :slight_smile: very curious what you’re using it with?

6

Hi again, unfortunately I’m still struggling with this and decided I should ask for some clarification.

When you mentioned “feedforwards” did you mean wL_FF_enable and bEMF_FF_enable?

Also, you mentioned the current / encoder bandwidths and the tuning webpage also mentions those but after reading as much as I can in the documents, forum and code, I’m not sure what to do with those values other than randomly try different numbers but that is getting me nowhere.

Is there a tuning procedure I can try for the bandwidths or a good explanation of what they should be somewhere?

My symptoms are sometimes the motor seems underpowered and sometimes it doesn’t. And sometimes I get CURRENT_LIMIT_VIOLATION when there isn’t a load and sometimes, I get MISSING_ESTIMATE errors. This is all during tuning different parameters so none of these are happening consistently - I’ve been kind of aimlessly trying different things.

It’s kind of like a simple arm on a rover

7

I also get a DRV_FAULT every now and then. I have a few other boards here; I’ll try some other ones and see if they behave the same.

It may be nothing, but one thing I’ve wondered about is this graph:

image
image1302×896 65.9 KB

My vel_limit is 70 and current limit (I assume that is current_soft_max) is 5 and when I tune my vel_gain I get around 0.001. With these numbers the parallelogram there leans over all the way to almost flat:

image

Maybe there’s something inherit about this motor/setup that doesn’t jive well with the assumptions made in the controller?

I have tried setting the torque_constant to 1, in which case the vel_gain is around 0.65 and the parallelogram is standing up, but didn’t notice any improvement in the issues I’m having.

8

I tested a few other controllers - none of them threw DRV_FAULT errors but I can’t get enough power out of them for what I need before throwing the CURRENT_LIMT_VIOLATION.

I tried bumping my input voltage up from 12 to 18V to see if that would help but no luck. I noticed my power supply is only giving about 9W when I’m getting the CURRENT_LIMIT_VIOLATION.