I’m a phD student in Control Theory working with quadcopters.
I’ve been testing the Navio2 board on my quadcopter in Stabilized mode, and it works just perfect, but when I switch to AltitudeHold, the quad doesn’t control the altitude and starts to fall down.
Also, when I see the readings of the barometer on MissionPlanner, it starts from 0.0m and then keeps decreasing until -7.5m without even touch the quad, completely still.
Is there a problem with the barometer? Do I need to calibrate it or something?
I really need the sensor to work in order to make some developments of altitude and position low-level control .
Another idea: I had a look at parameters evolution while checking my navio2 configuration.
Displayed altitude in GCS is from GPS calculation. If you want an accurate baro altitude (or baro variation), check press_abs (hectoPascal) or raw_press (hPa x 100).
Displayed altitude is reset to zero when arming (we do not expect large change in GPS calculated altitude between take-off and landing).
On the bench, press_abs variation is less than ± 0.01hectoPascal (8cm).
In order to maintain altitude in Altitude Hold mode, Power lever had to be in the middle. If it is below, aircraft descend, above it climb (out of the dead zone THR_DZ).
In order to have throttle at the middle in stabilise mode, you have to adjust MOT_THST_HOVER
I was checking the values of press_abs and raw_press and they maintain pretty stable, also the values from the Barometer example program.
But the altitude itself keeps varing a lot, and I haven’t done a decent flight on AltHold mode yet. It keeps falling down when I change from Stabilize to AltHold, throttle at 50%, and when I try to get it up increasing the throttle it keeps ascending without any control.
