diff --git a/docs/assets/config/fw/autotune.png b/docs/assets/config/fw/autotune.png new file mode 100644 index 0000000000..768d26787d Binary files /dev/null and b/docs/assets/config/fw/autotune.png differ diff --git a/docs/en/config/_autotune.md b/docs/en/config/_autotune.md index 0a87201c7a..9bf06a4f88 100644 --- a/docs/en/config/_autotune.md +++ b/docs/en/config/_autotune.md @@ -91,9 +91,17 @@ The test steps are: 3. Ensure that the **Autotune enabled** button is enabled (this will display the **Autotune** button and remove the manual tuning selectors). 4. Read the warning popup and click on **OK** to start tuning. +
+ 4. The drone will first start to perform quick roll motions followed by pitch and yaw motions. The progress is shown in the progress bar, next to the _Autotune_ button. +
+ +4. The drone will first start to perform quick roll motions followed by pitch and yaw motions. When [`FW_AT_SYSID_TYPE`](../advanced_config/parameter_reference.md#FW_AT_SYSID_TYPE) is set to linear/logarithmic sine sweep (recommended), the max rates are approximately 45 deg/s for roll and 30 deg/s for pitch and yaw. + The progress is shown in the progress bar, next to the _Autotune_ button. + +
5. Manually land and disarm to apply the new tuning parameters. @@ -104,6 +112,13 @@ The test steps are: 5. The tuning will be immediately/automatically be applied and tested in flight (by default). PX4 will then run a 4 second test and revert the new tuning if a problem is detected. +The figure below shows how steps 4 and 5 might look in flight on the pitch axis. +The pitch rate gradually increases up until it reaches the target. +This amplitude is then held while the signal frequency is increased. +You can then see how the tuned system is able to follow the setpoint in the test signal. + + +
::: warning @@ -170,9 +185,23 @@ Fast oscillations (more than 1 oscillation per second): this is because the gain ### The auto-tuning sequence fails +
+ If the drone was not moving enough during auto-tuning, the system identification algorithm might have issues to find the correct coefficients. -Increase the
[MC_AT_SYSID_AMP](../advanced_config/parameter_reference.md#MC_AT_SYSID_AMP)
[FW_AT_SYSID_AMP](../advanced_config/parameter_reference.md#FW_AT_SYSID_AMP)
parameter by steps of 1 and trigger the auto-tune again. +Increase the [MC_AT_SYSID_AMP](../advanced_config/parameter_reference.md#MC_AT_SYSID_AMP) parameter by steps of 1 and trigger the auto-tune again. + +
+
+ +By default, the autotune maneuvers ensure that a sufficient angular rate is reached for system identification. The target rates are approximately 45 deg/s for roll and 30 deg/s for pitch and yaw. + +If the signal-to-noise ratio of the vehicle is low, the system identification algorithm might have issues finding the correct coefficients. Ensure that there is no excessive noise and/or platform vibration. + + + +
+ ### The drone oscillates after auto-tuning