I am troubleshooting an issue that led to a crash while in Loiter mode. The drone in question is a heavier drone (~6-7 kg).
Before this test, we had flown the same drone successfully at 100m altitude, traveling 150-200m forward without any issues. As we were testing the impact of setting:
- LOIT_SPEED = 3500 cm/s (35 m/s)
- LOIT_ANG_MAX = 10°
Later during the next flight after changing the battery and re-flying, when we were specifically testing the impact of setting:
- LOIT_SPEED = 3500 cm/s (35 m/s)
- LOIT_ANG_MAX = 5°
We observed a motor failure when reversing yaw direction.
Critical Issue Observed:
- When the pilot yaws the drone anticlockwise and then applies a small clockwise yaw command,
→ Motor (C4) suddenly loses power, causing the drone to fall.
This can be seen in log using ATT>YAW and RCOU>C1, C2, C3, C4 and RCIN>C2
Additionally you can also plot the GPS>ALT to see when the altitude drops.
Observed Logs & Parameter Settings:
1. Yaw Instability (ATT Log)
2. High Vibrations (VIBE Log)
3. Motor Output Imbalance (RCOU Log)
4. Pilot Command for YAW (RCIN Log)
Current Parameter Settings:
Yaw PID Tuning (ATC_RAT_YAW)
| Parameter | Current Value | Default Value |
|---|---|---|
| ATC_RAT_YAW_P | 0.462 | 0.18 |
| ATC_RAT_YAW_I | 0.0462 | 0.018 |
| ATC_RAT_YAW_D | 0.0024 | 0 |
Other setting for YAW can be seen using the log.
Loiter Mode Parameters
| Parameter | Current Value | Default Value |
|---|---|---|
| LOIT_ACC_MAX | 300 cm/s² | 500 cm/s² |
| LOIT_ANG_MAX | 5° | N/A |
| LOIT_SPEED | 3500 cm/s | 1250 cm/s |
Acceleration and Jerk Limits
| Parameter | Current Value | Default Value |
|---|---|---|
| ATC_ACCEL_Y_MAX | 6500 cdeg/s² | 27000 cdeg/s² |
Request for Help:
- How should I further refine my Yaw PID tuning?
- Could my ESC/motor combination be causing desync in yaw transitions?
- Would increasing ATC_ACCEL_Y_MAX significantly improve yaw response?
- Are there any known firmware issues or flight controller settings that could cause this behavior?
I have attached log files with parameter settings for reference. Any recommendations would be greatly appreciated!
LINK - 2025-01-17 14-41-53 (1).bin - Google Drive
3 posts - 3 participants
