I have a 900kv motor (Scorpion HK-3014-900KV) tracking a velocity setpoint in sensorless mode using v3.5 of the ODrive hardware. I have release v0.4.1 of the firmware that I have added to ability to set the pm_flux_linkage Post. The motor spins up and regulates velocity great until I get to a high enough requested velocity (around 3000 rad/s electrical). The motor then begins to shutter as if it is bouncing off a limit or going unstable. When the motor shutters both the resistor and motor start to get warm/hot. If I keep increasing velocity the driver eventual shuts down with an error code 0x31:
ERROR_INVALID_STATE
ERROR_BRAKE_RESISTOR_DISARMED
ERROR_MOTOR_DISARMED
I have tried replacing my 24V 10 A power supply with a LiPo battery, setting the brake resistance to zero so that the battery is the sink for braking, increasing the current_lim, and tuning the velocity controller. I think the instability may be coming from the current controller and I was going to decrease the gains to see if there is any improvement. I wanted to get a second pair of eyes on my setup to make sure I have not missed anything obvious, or if there are any additional suggestions.
Below is a print out of the axis state after a failure resulting in an error code of 0x31.
motor:
gate_driver: ...
armed_state = 0 (int)
current_meas_phB = -0.038694679737091064 (float)
DC_calib_phC = -1.7575383186340332 (float)
current_control:
v_current_control_integral_q = 0.0 (float)
i_gain = 43.920989990234375 (float)
p_gain = 0.010267496109008789 (float)
Iq_measured = -71.01968383789062 (float)
v_current_control_integral_d = 0.0 (float)
Iq_setpoint = 1.8226861953735352 (float)
final_v_alpha = -6.225567817687988 (float)
max_allowed_current = 71.99999237060547 (float)
final_v_beta = -5.765687942504883 (float)
Ibus = -53.85747146606445 (float)
DC_calib_phB = -0.8072223663330078 (float)
current_meas_phC = -0.0551450252532959 (float)
phase_current_rev_gain = 0.02500000037252903 (float)
config:
current_lim = 10.0 (float)
resistance_calib_max_voltage = 1.0 (float)
direction = 1 (int)
phase_resistance = 0.04392099007964134 (float)
pre_calibrated = True (bool)
phase_inductance = 1.0267495781590696e-05 (float)
requested_current_range = 70.0 (float)
motor_type = 0 (int)
pole_pairs = 5 (int)
calibration_current = 10.0 (float)
timing_log: ...
is_calibrated = True (bool)
error = 0x0000 (int)
current_state = 1 (int)
controller:
set_current_setpoint(current_setpoint: float)
current_setpoint = 0.0 (float)
pos_setpoint = 0.0 (float)
vel_integrator_current = 0.0 (float)
vel_setpoint = 0.0 (float)
config:
vel_limit = 7500.0 (float)
pos_gain = 20.0 (float)
control_mode = 2 (int)
vel_integrator_gain = 0.0010000000474974513 (float)
vel_gain = 0.0024999999441206455 (float)
set_vel_setpoint(vel_setpoint: float, current_feed_forward: float)
set_pos_setpoint(pos_setpoint: float, vel_feed_forward: float, current_feed_forward: float)
start_anticogging_calibration()
encoder: …
requested_state = 0 (int)
loop_counter = 360370 (int)
sensorless_estimator:
phase = 2.0527780055999756 (float)
pm_flux_linkage = 0.0012251753360033035 (float)
pll_pos = 1.9686251878738403 (float)
pll_vel = 4027.0927734375 (float)
pll_ki = 1000000.0 (float)
error = 0x0000 (int)
pll_kp = 2000.0 (float)
enable_step_dir = False (bool)
error = 0x0031 (int)
config:
ramp_up_distance = 12.566370964050293 (float)
counts_per_step = 2.0 (float)
spin_up_target_vel = 1500.0 (float)
spin_up_acceleration = 800.0 (float)
startup_encoder_offset_calibration = False (bool)
startup_encoder_index_search = False (bool)
spin_up_current = 10.0 (float)
ramp_up_time = 0.4000000059604645 (float)
startup_closed_loop_control = False (bool)
startup_sensorless_control = False (bool)
enable_step_dir = False (bool)
startup_motor_calibration = False (bool)