Still some issue with zero throttle before RTH failsafe in 1.8

[rb1205]

Condition: SP3 EVO board, fully functional quadcopter with RTH failsafe procedure

Test Take props away, power on the quad and the TX, arm the quad, raise thrust to about 50%, then engage Failsafe either by aux command or by switching off the radio. Observe how motors behave. Disengage failsafe (make sure it is in fact disengaged), zero the thrust, engage Failsafe again. Observe how motors behave.

What happens When the failsafe is engaged with some throttle, during failsafe the motors will change their overall RPM, and if you move the quad up and down the overall RPM will change to attempt to compensate the movement (increase when falling, decrease when rising). However, if the throttle was idle when the failsafe engaged, then the motors are kept overall idle as well, even if you move the quad up and down.

What should happen Failsafe behavior shouldn't be affected by throttle position at all (except for failsafe_throttle, which has nothing to do with this). Controller should definitely increase overall RPM if the quad is losing altitude.

Hypotesis If you try to move around the quad while it's in failsafe, you can see how the attitude PIDs (both rate and angle) seem to work correctly with and without RC throttle, albeit with much different range of intervention on the actual RPM of the motors. IMHO the problem lies with the althold which, if failsafe was engaged with zero throttle command, is not working and thus forcing the overall thrust to be zero and is disabling the PIDs I-terms, similarly to what an idle thrust RC command would do.

NOTE: I don't know if it's relevant, but i use nav_use_midthr_for_althold.

[digitalentity]

Please provide your settings. We can't guess how your machine is configured.

[rb1205]

version

INAV/SPRACINGF3EVO 1.8.0 Oct 24 2017 / 06:58:38 (0f1975ce)

resources

mixer

mixer QUADX

mmix reset

servo

servo 0 1000 2000 1500 100 -1 servo 1 1000 2000 1500 100 -1 servo 2 1000 2000 1500 100 -1 servo 3 1000 2000 1500 100 -1 servo 4 1000 2000 1500 100 -1 servo 5 1000 2000 1500 100 -1 servo 6 1000 2000 1500 100 -1 servo 7 1000 2000 1500 100 -1

servo mix

smix reset

feature

feature -RX_PPM feature -VBAT feature -RX_UIB feature -RX_SERIAL feature -MOTOR_STOP feature -SERVO_TILT feature -SOFTSERIAL feature -GPS feature -TELEMETRY feature -CURRENT_METER feature -3D feature -RX_PARALLEL_PWM feature -RX_MSP feature -RSSI_ADC feature -LED_STRIP feature -DASHBOARD feature -BLACKBOX feature -CHANNEL_FORWARDING feature -TRANSPONDER feature -AIRMODE feature -SUPEREXPO feature -VTX feature -RX_SPI feature -SOFTSPI feature -PWM_SERVO_DRIVER feature -PWM_OUTPUT_ENABLE feature -OSD feature VBAT feature SOFTSERIAL feature GPS feature TELEMETRY feature CURRENT_METER feature LED_STRIP feature BLACKBOX feature PWM_OUTPUT_ENABLE

beeper

beeper RUNTIME_CALIBRATION beeper HW_FAILURE beeper RX_LOST beeper RX_LOST_LANDING beeper DISARMING beeper ARMING beeper ARMING_GPS_FIX beeper BAT_CRIT_LOW beeper BAT_LOW beeper GPS_STATUS beeper RX_SET beeper ACTION_SUCCESS beeper ACTION_FAIL beeper READY_BEEP beeper MULTI_BEEPS beeper DISARM_REPEAT beeper ARMED beeper SYSTEM_INIT beeper ON_USB beeper LAUNCH_MODE beeper CAM_CONNECTION_OPEN beeper CAM_CONNECTION_CLOSED

map

map AETR5678

name

name -

serial

serial 20 1 115200 38400 0 115200 serial 0 2 115200 38400 0 115200 serial 1 64 115200 38400 0 115200 serial 2 32 115200 38400 0 115200 serial 30 1 19200 38400 0 115200 serial 31 1 19200 38400 0 115200

led

led 0 0,0::AOW:10 led 1 1,0::AOW:1 led 2 2,0::AOW:1 led 3 3,0::AOW:1 led 4 4,0::AOW:1 led 5 5,0::AOW:10 led 6 0,0::C:0 led 7 0,0::C:0 led 8 0,0::C:0 led 9 0,0::C:0 led 10 0,0::C:0 led 11 0,0::C:0 led 12 0,0::C:0 led 13 0,0::C:0 led 14 0,0::C:0 led 15 0,0::C:0 led 16 0,0::C:0 led 17 0,0::C:0 led 18 0,0::C:0 led 19 0,0::C:0 led 20 0,0::C:0 led 21 0,0::C:0 led 22 0,0::C:0 led 23 0,0::C:0 led 24 0,0::C:0 led 25 0,0::C:0 led 26 0,0::C:0 led 27 0,0::C:0 led 28 0,0::C:0 led 29 0,0::C:0 led 30 0,0::C:0 led 31 0,0::C:0

color

color 0 0,0,0 color 1 0,255,255 color 2 0,0,255 color 3 30,0,255 color 4 60,0,255 color 5 90,0,255 color 6 120,0,255 color 7 150,0,255 color 8 180,0,255 color 9 210,0,255 color 10 240,0,255 color 11 270,0,255 color 12 300,0,255 color 13 330,0,255 color 14 0,0,0 color 15 0,0,0

mode_color

mode_color 0 0 1 mode_color 0 1 11 mode_color 0 2 2 mode_color 0 3 13 mode_color 0 4 10 mode_color 0 5 3 mode_color 1 0 5 mode_color 1 1 11 mode_color 1 2 3 mode_color 1 3 13 mode_color 1 4 10 mode_color 1 5 3 mode_color 2 0 10 mode_color 2 1 11 mode_color 2 2 4 mode_color 2 3 13 mode_color 2 4 10 mode_color 2 5 3 mode_color 3 0 8 mode_color 3 1 11 mode_color 3 2 4 mode_color 3 3 13 mode_color 3 4 10 mode_color 3 5 3 mode_color 4 0 7 mode_color 4 1 11 mode_color 4 2 3 mode_color 4 3 13 mode_color 4 4 10 mode_color 4 5 3 mode_color 5 0 9 mode_color 5 1 11 mode_color 5 2 2 mode_color 5 3 13 mode_color 5 4 10 mode_color 5 5 3 mode_color 6 0 2 mode_color 6 1 6 mode_color 6 2 1 mode_color 6 3 0 mode_color 6 4 0 mode_color 6 5 2 mode_color 6 6 3 mode_color 6 7 6 mode_color 6 8 0 mode_color 6 9 0 mode_color 6 10 0

aux

aux 0 0 0 1350 2100 aux 1 1 2 1800 2100 aux 2 2 2 1350 1650 aux 3 20 0 1800 2100 aux 4 4 1 1350 1650 aux 5 5 1 1800 2100 aux 6 6 8 900 1200 aux 7 3 4 1350 2100 aux 8 9 4 1800 2100 aux 9 8 3 1350 1650 aux 10 21 8 1800 2100 aux 11 11 10 1800 2100 aux 12 12 10 900 1200 aux 13 15 6 1800 2100 aux 14 18 3 1800 2100 aux 15 0 0 900 900 aux 16 0 0 900 900 aux 17 0 0 900 900 aux 18 0 0 900 900 aux 19 0 0 900 900

adjrange

adjrange 0 0 0 900 900 0 0 adjrange 1 0 0 900 900 0 0 adjrange 2 0 0 900 900 0 0 adjrange 3 0 0 900 900 0 0 adjrange 4 0 0 900 900 0 0 adjrange 5 0 0 900 900 0 0 adjrange 6 0 0 900 900 0 0 adjrange 7 0 0 900 900 0 0 adjrange 8 0 0 900 900 0 0 adjrange 9 0 0 900 900 0 0 adjrange 10 0 0 900 900 0 0 adjrange 11 0 0 900 900 0 0

rxrange

rxrange 0 1000 2000 rxrange 1 1000 2000 rxrange 2 1000 2000 rxrange 3 1000 2000

master

set looptime = 1000 set gyro_sync = ON set gyro_sync_denom = 1 set align_gyro = DEFAULT set gyro_hardware_lpf = 42HZ set gyro_lpf_hz = 60 set moron_threshold = 32 set gyro_notch1_hz = 160 set gyro_notch1_cutoff = 120 set gyro_notch2_hz = 0 set gyro_notch2_cutoff = 60 set vbat_adc_channel = 1 set rssi_adc_channel = 3 set current_adc_channel = 2 set airspeed_adc_channel = 0 set acc_notch_hz = 0 set acc_notch_cutoff = 1 set align_acc = DEFAULT set acc_hardware = MPU6500 set acc_lpf_hz = 15 set acczero_x = 557 set acczero_y = 127 set acczero_z = -442 set accgain_x = 4096 set accgain_y = 4084 set accgain_z = 4042 set rangefinder_hardware = NONE set align_mag = DEFAULT set mag_hardware = AK8963 set mag_declination = 0 set magzero_x = 13 set magzero_y = -20 set magzero_z = -139 set mag_calibration_time = 30 set baro_hardware = BMP280 set baro_use_median_filter = ON set pitot_hardware = NONE set pitot_use_median_filter = ON set pitot_noise_lpf = 0.600 set pitot_scale = 1.000 set receiver_type = SERIAL set mid_rc = 1500 set min_check = 1100 set max_check = 1900 set rssi_channel = 16 set rssi_scale = 100 set rssi_invert = OFF set rc_smoothing = ON set serialrx_provider = SBUS set sbus_inversion = ON set rx_spi_rf_channel_count = 0 set spektrum_sat_bind = 0 set rx_min_usec = 885 set rx_max_usec = 2115 set blackbox_rate_num = 1 set blackbox_rate_denom = 1 set blackbox_device = SDCARD set sdcard_detect_inverted = ON set min_throttle = 1050 set max_throttle = 1850 set min_command = 940 set motor_pwm_rate = 1000 set motor_pwm_protocol = ONESHOT125 set failsafe_delay = 5 set failsafe_recovery_delay = 5 set failsafe_off_delay = 200 set failsafe_throttle = 1300 set failsafe_throttle_low_delay = 100 set failsafe_procedure = RTH set failsafe_stick_threshold = 50 set failsafe_fw_roll_angle = -200 set failsafe_fw_pitch_angle = 100 set failsafe_fw_yaw_rate = -45 set failsafe_min_distance = 0 set failsafe_min_distance_procedure = DROP set align_board_roll = 12 set align_board_pitch = -24 set align_board_yaw = 900 set gimbal_mode = NORMAL set battery_capacity = 3300 set vbat_scale = 108 set vbat_max_cell_voltage = 43 set vbat_min_cell_voltage = 35 set vbat_warning_cell_voltage = 35 set current_meter_scale = 448 set current_meter_offset = 64 set multiwii_current_meter_output = OFF set current_meter_type = VIRTUAL set yaw_motor_direction = 1 set yaw_jump_prevention_limit = 200 set 3d_deadband_low = 1406 set 3d_deadband_high = 1514 set 3d_neutral = 1460 set servo_center_pulse = 1500 set servo_pwm_rate = 50 set servo_lpf_hz = 20 set flaperon_throw_offset = 200 set tri_unarmed_servo = ON set reboot_character = 82 set imu_dcm_kp = 2500 set imu_dcm_ki = 50 set imu_dcm_kp_mag = 10000 set imu_dcm_ki_mag = 0 set small_angle = 25 set fixed_wing_auto_arm = OFF set disarm_kill_switch = ON set auto_disarm_delay = 5 set gps_provider = UBLOX7 set gps_sbas_mode = EGNOS set gps_dyn_model = AIR_4G set gps_auto_config = ON set gps_auto_baud = ON set gps_min_sats = 6 set deadband = 3 set yaw_deadband = 3 set pos_hold_deadband = 20 set alt_hold_deadband = 50 set 3d_deadband_throttle = 50 set fw_autotune_overshoot_time = 100 set fw_autotune_undershoot_time = 200 set fw_autotune_threshold = 50 set fw_autotune_ff_to_p_gain = 10 set fw_autotune_ff_to_i_tc = 600 set inav_auto_mag_decl = ON set inav_gravity_cal_tolerance = 5 set inav_use_gps_velned = ON set inav_gps_delay = 200 set inav_reset_altitude = FIRST_ARM set inav_max_surface_altitude = 200 set inav_w_z_surface_p = 3.500 set inav_w_z_surface_v = 6.100 set inav_w_z_baro_p = 0.350 set inav_w_z_gps_p = 0.200 set inav_w_z_gps_v = 0.500 set inav_w_xy_gps_p = 1.000 set inav_w_xy_gps_v = 2.000 set inav_w_z_res_v = 0.500 set inav_w_xy_res_v = 0.500 set inav_w_acc_bias = 0.010 set inav_max_eph_epv = 1000.000 set inav_baro_epv = 100.000 set nav_disarm_on_landing = ON set nav_use_midthr_for_althold = ON set nav_extra_arming_safety = OFF set nav_user_control_mode = CRUISE set nav_position_timeout = 5 set nav_wp_radius = 100 set nav_wp_safe_distance = 10000 set nav_auto_speed = 500 set nav_auto_climb_rate = 400 set nav_manual_speed = 400 set nav_manual_climb_rate = 200 set nav_landing_speed = 200 set nav_land_slowdown_minalt = 500 set nav_land_slowdown_maxalt = 1500 set nav_emerg_landing_speed = 300 set nav_min_rth_distance = 500 set nav_rth_climb_first = ON set nav_rth_climb_ignore_emerg = OFF set nav_rth_tail_first = OFF set nav_rth_allow_landing = ALWAYS set nav_rth_alt_mode = AT_LEAST set nav_rth_abort_threshold = 10000 set nav_rth_altitude = 2000 set nav_mc_bank_angle = 45 set nav_mc_hover_thr = 1400 set nav_mc_auto_disarm_delay = 2000 set nav_fw_cruise_thr = 1400 set nav_fw_min_thr = 1200 set nav_fw_max_thr = 1700 set nav_fw_bank_angle = 20 set nav_fw_climb_angle = 20 set nav_fw_dive_angle = 15 set nav_fw_pitch2thr = 10 set nav_fw_loiter_radius = 5000 set nav_fw_land_dive_angle = 2 set nav_fw_launch_velocity = 300 set nav_fw_launch_accel = 1863 set nav_fw_launch_max_angle = 45 set nav_fw_launch_detect_time = 40 set nav_fw_launch_thr = 1700 set nav_fw_launch_idle_thr = 1000 set nav_fw_launch_motor_delay = 500 set nav_fw_launch_spinup_time = 100 set nav_fw_launch_timeout = 5000 set nav_fw_launch_climb_angle = 18 set telemetry_switch = OFF set telemetry_inversion = ON set frsky_default_latitude = 0.000 set frsky_default_longitude = 0.000 set frsky_coordinates_format = 0 set frsky_unit = METRIC set frsky_vfas_precision = 0 set frsky_vfas_cell_voltage = OFF set hott_alarm_sound_interval = 5 set smartport_uart_unidir = OFF set smartport_fuel_percent = OFF set ibus_telemetry_type = 0 set ltm_update_rate = NORMAL set ledstrip_visual_beeper = ON set i2c_speed = 400KHZ set cpu_underclock = OFF set debug_mode = NONE set acc_task_frequency = 500 set attitude_task_frequency = 250 set async_mode = NONE set throttle_tilt_comp_str = 30 set input_filtering_mode = OFF set mode_range_logic_operator = OR set stats = OFF set stats_total_time = 0 set stats_total_dist = 0 set tz_offset = 0

profile

profile 1

set mc_p_pitch = 38 set mc_i_pitch = 31 set mc_d_pitch = 55 set mc_p_roll = 34 set mc_i_roll = 20 set mc_d_roll = 50 set mc_p_yaw = 55 set mc_i_yaw = 30 set mc_d_yaw = 30 set mc_p_level = 20 set mc_i_level = 15 set mc_d_level = 75 set fw_p_pitch = 20 set fw_i_pitch = 35 set fw_ff_pitch = 10 set fw_p_roll = 25 set fw_i_roll = 35 set fw_ff_roll = 10 set fw_p_yaw = 50 set fw_i_yaw = 45 set fw_ff_yaw = 0 set fw_p_level = 20 set fw_i_level = 15 set fw_d_level = 75 set max_angle_inclination_rll = 450 set max_angle_inclination_pit = 450 set dterm_lpf_hz = 40 set yaw_lpf_hz = 30 set dterm_setpoint_weight = 0.000 set fw_iterm_throw_limit = 165 set fw_reference_airspeed = 1000.000 set fw_turn_assist_yaw_gain = 1.000 set dterm_notch_hz = 160 set dterm_notch_cutoff = 105 set pidsum_limit = 500 set yaw_p_limit = 300 set iterm_ignore_threshold = 200 set yaw_iterm_ignore_threshold = 50 set rate_accel_limit_roll_pitch = 2000 set rate_accel_limit_yaw = 2000 set heading_hold_rate_limit = 90 set nav_mc_pos_z_p = 50 set nav_mc_pos_z_i = 0 set nav_mc_pos_z_d = 0 set nav_mc_vel_z_p = 100 set nav_mc_vel_z_i = 50 set nav_mc_vel_z_d = 10 set nav_mc_pos_xy_p = 65 set nav_mc_pos_xy_i = 120 set nav_mc_pos_xy_d = 10 set nav_mc_vel_xy_p = 180 set nav_mc_vel_xy_i = 15 set nav_mc_vel_xy_d = 100 set nav_fw_pos_z_p = 50 set nav_fw_pos_z_i = 0 set nav_fw_pos_z_d = 0 set nav_fw_pos_xy_p = 75 set nav_fw_pos_xy_i = 5 set nav_fw_pos_xy_d = 8 set rc_expo = 0 set rc_yaw_expo = 0 set thr_mid = 50 set thr_expo = 0 set roll_rate = 36 set pitch_rate = 36 set yaw_rate = 26 set tpa_rate = 30 set tpa_breakpoint = 1600

[digitalentity]

@rb1205 thanks! I assume you test at home without GPS fix, right? Blackbox logs of your described scenarious would also be very helpful.

[rb1205]

Tested both with and without GPS fix*, same results.

Sure, I will make a blackbox log in the afternoon.

EDIT: I didn't move the quad when I tested it with the GPS fix, so it went straight to landing mode.

[rb1205]

Here you go, blackbox with 50% throttle and with no throttle . Notice how the roll PID I term is building up in the 50% throttle log, and is forced to 0 in the no throttle one. It's like the I term cutoff is retained in the failsafe.

I also set nav_use_midthr_for_althold to OFF, got same results.

[rb1205]

Here's an even clearer log of the bug: I arm, trigger failsafe mode with some throttle, let the I-terms slowly build up then, at t=37.88 seconds still in failsafe mode I zero the throttle on the radio. The PIDs I-terms are immediately zeroed. I also tried this with airmode enabled, got same results.

Am I wrong in assuming that failsafe should completely ignore rcCommand values?

Oh, in the meanwhile I upgraded to inav 1.8, I updated the title

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