Autopilot Tuning

Controller tuning can be tricky. In this section we'll provide some general guidelines to help.

Longitudinal Autopilot Tuning

We recommend tuning the gains one at a time in the following order. All gains are assumed to start at 0.

Inner Loop: Pitch Attitude Hold

1. Increase k_{d_\theta} until the vehicle becomes unstable and then back of 20%.
2. Increase k_{p_\theta} to get acceptable responsiveness.

Outer Loop: Altitude Hold

1. Increase k_{p_z} to get acceptable responsiveness.
2. Increase k_{i_z} to eliminate steady state errors.

Outer Loop: Pitch Control of Airspeed

1. Increase k_{p_{V_2}} to get acceptable responsiveness.
2. Increase k_{i_{V_2}} to eliminate steady state errors.

Inner Loop: Throttle Control of Airspeed

1. Increase k_{p_V} to get acceptable responsiveness.
2. Increase k_{i_V} to eliminate steady state errors.

Lateral Autopilot Tuning

Inner Loop: Roll Attitude Hold

1. Increase k_{d_\phi} until the vehicle becomes unstable and then back of 20%.
2. Increase k_{p_\phi} to get acceptable responsiveness.

Outer Loop: Course Hold

1. Increase k_{p_\chi} to get acceptable responsiveness.
2. Increase k_{i_\chi} to eliminate steady state errors.

Inner Loop: Sideslip Hold

1. Increase k_{p_\beta} to get acceptable responsiveness.
2. Increase k_{i_\beta} to eliminate steady state errors.