I encountered a similar issue and would be curious to know if this helps anyone else.
- Changing to depth hold mode caused the vehicle to engage the vertical (I’m assuming Z axis) thrusters at maximum speed and cause the vehicle to dive and continue diving until it reached the bottom.
- Changing to stablize mode caused the vehicle to attempt to roll 360 degrees in the pitch/roll axes.
Environment:
Board name: Navigator
Manufacturer: Blue Robotics
Mavlink platform: navigator
Firmware version: 4.1.0 (STABLE)
Vehicle type: Submarine
After taking some time to debug the issue, I discovered that this behaviour occurs for me when performing the following steps:
- Open QGroundControl and connect to the vehicle
- Change flight mode to manual
- Arm vehicle
- Pilot vehicle around normally with joystick
- Change flight mode to depth hold
- Vehicle immediately dives with maximum Z thrusters
- Change flight mode to manual
- Pilot vehicle around normally
- Change flight mode to stabilize
- Vehicle immediately attempts to pitch/roll 360 degrees
The behaviour does not occur, however, if the following steps are performed:
- Open QGroundControl and connect to the vehicle
- Change flight mode to depth hold
- Arm vehicle
- Pilot vehicle around normally with depth hold
- Change flight mode to manual
- Pilot vehicle around normally with joystick
- Change flight mode to stabilize
- Pilot vehicle around normally with stabilize
- Repeat
Thus, from my limited experience: it appears to be an issue with selecting manual mode as the first mode, arming, and then attempting to transition to other flight modes. As long as selected depth hold first and then armed, everything worked as expected, and I could freely transition between manual/stabilize/depth hold.