Altitude mode not work

GT92 · March 12, 2024, 10:48am

Good morning all,
During indoor test, when we try to activate the altitude mode, QGROUNDCONTROL STATION, reports the error not valid altitude estimate
My configuration is:
-Pixhawk 6X

Lidar TF MINI PLUS
For EKF2 setup i followed the indication reported in the table below (Indoor Flat Terrain)
The LIDAR is working, in fact when I read the altitude from MAVLINK Ispector the altitude reported is correct )
i’ll attach a log file
https://review.px4.io/plot_app?log=700a0b35-2834-4e1a-9397-f4f1947d0d4a
Kind regards,
Giuseppe

Igor_Misic · March 12, 2024, 1:49pm

It seems you never entered here:

github.com

PX4/PX4-Autopilot/blob/9f4ae0a85d48c6c5f189d6c2ffe99173d8171a8f/src/modules/commander/HealthAndArmingChecks/checks/estimatorCheck.cpp#L831


      
          	failsafe_flags.local_position_invalid_relaxed =
          		!checkPosVelValidity(now, xy_valid, lpos.eph, lpos_eph_threshold_relaxed, lpos.timestamp,
          				     _last_lpos_relaxed_fail_time_us, !failsafe_flags.local_position_invalid_relaxed);
          
          	failsafe_flags.local_velocity_invalid =
          		!checkPosVelValidity(now, v_xy_valid, lpos.evh, _param_com_vel_fs_evh.get(), lpos.timestamp,
          				     _last_lvel_fail_time_us, !failsafe_flags.local_velocity_invalid);
          
          
          	// altitude
          	failsafe_flags.local_altitude_invalid = !lpos.z_valid || (now > lpos.timestamp + (_param_com_pos_fs_delay.get() * 1_s));
          
          
          	// attitude
          	vehicle_attitude_s attitude;
          
          	if (_vehicle_attitude_sub.copy(&attitude)) {
          		const matrix::Quatf q{attitude.q};
          		const float eps = 1e-5f;
          		const bool no_element_larger_than_one = (fabsf(q(0)) <= 1.f + eps)
          							&& (fabsf(q(1)) <= 1.f + eps)

local_altitude_invalid is invalid all the time even z_valid is valid.

GT92 · March 12, 2024, 2:16pm

Hi Igor,
Firstly I want to thank you for the fast reply.
Unfortunaly I’m pretty new to PX4 firmware, what action I had to take in order to solve the problems?
Looking forward to hear from you I wish you an happy days

Igor_Misic · March 12, 2024, 2:51pm

It is hard to tell without a debugger hooked. It could be a bug. Have you maybe disabled some preflight checks?

local_altitude_invalid is by default true

GT92 · March 12, 2024, 4:08pm

Hi Igor,
I found that COM_POS_FS_DELAY was set to 0, i changed it to 1 second and it seem to work, it’s possible that this is the issue?

Igor_Misic · March 12, 2024, 4:24pm

Doesn’t make sense since value 1 shall only delay this for 1 second to be true.
(now > lpos.timestamp + (_param_com_pos_fs_delay.get() * 1_s))

coolvision · March 12, 2024, 4:38pm

in your altitude estimate in the log, you only have the barometer. so you need to put barometer as EKF2_HGT_REF.

also check if SYS_HAS_GPS is disabled, and all other relevant parameters that allow using GPS.

Igor_Misic · March 12, 2024, 5:07pm

he has a distance sensor and EKF_HGT_REF set to 2 (for distance sensor).
That looks correct.