Issue
Tuning Resolution
My aircraft climbs or
descends too
quickly/slowly in altitude
and position mode
Adjust MPC_Z_VEL_MAX_DN and MPC_Z_VEL_MAX_UP. They
control the maximum speed
My aircraft accelerates
too slowly or quickly in
position mode
Adjust parameter MPC_ACC_HOR to increase or decrease the
acceleration used to reach the desired velocity. Value is m/s^2
Adjust parameters MPC_ACC_UP/DOWN_MAX to control how
fast the aircraft accelerates vertically.
{% hint style="info" %} Loading the defaults or known-good presets will allow you to quickly
return functional ALTA X if there is ever uncertainty about changes to the tuning properties.
{% endhint %}
Sensor Calibration
ALTA X features redundant, highly sensitive 3-axis magnetometers, gyroscopes, and
accelerometers that measure specific force, angular rate, and earth’s magnetic field to infer
heading and maintain stability. Occasionally, the sensors will require re-calibration.
{% hint style="info" %} ALTA X’s compass may require calibration if locations have changed.
For best results, it is recommended to perform manual compass calibrations away from
ferrous objects, buildings and vehicles. In addition, concrete can contain steel rebar which
may influence compass calibrations. {% endhint %}
{% hint style="info" %} Perform calibration without a payload attached and all motor
booms extended and latched. Folded booms will cause an inaccurate calibration.
It is recommended to use two people to perform the compass calibration as it requires
handling and rotating ALTA X. {% endhint %}
{% hint style="info" %} Alta X has 4 magnetometers, one in the GPS mast, and 3 internally
used as backups. In cases where a payload is mounted that affects the onboard
magnetometers more than the external one, QGroundControl will notify the user that
