Advanced parameters tuning for evaluating the control performance

Definition:

The PX4 position controller consists of an outer P position-control loop and an inner PID velocity-control loop as shown in the following figure. 

Usually in PX4,  position-control represents the case where both loops are active while velocity-control refers to the case when only the velocity control loop is in use.

Multicopter position controller [1]

Here are some parameters you can set for realizing better control performance [3]. Make sure you have finished the basic PID tuning before tuning the parameters mentioned in this article.

1. MPC_HOLD_DZ: Deadzone of sticks where position hold is enabled.
2. MPC_ACC_HOR_MAX: Maximum horizontal acceleration for auto mode and for manual mode.
3. MPC_ACC_HOR: Acceleration for auto and for manual.
4. MPC_DEC_HOR_SLOW: Slow horizontal manual deceleration for manual mode.
5. MPC_ACC_UP_MAX: Maximum vertical acceleration in velocity controlled modes upward.
6. MPC_ACC_DOWN_MAX: Maximum vertical acceleration in velocity controlled modes down.

***The lag will be more significant the larger the value of MPC_ACC_HOR.***

Reference:
[1] https://dev.px4.io/en/flight_stack/controller_diagrams.html#multicopter-position-controller
[2] https://docs.px4.io/en/config_mc/advanced_mc_position_tuning.html
[3] https://docs.px4.io/en/advanced_config/parameter_reference.html#MPC_ACC_HOR