Our ROV is experiencing a propulsion issue, and I would appreciate any advice or insights.
During a test dive, the ROV is able to rotate clockwise and counterclockwise, and it can also perform lateral (sideways) movements normally. However, it is unable to move forward or backward.
The forward/backward thrusters are new and correctly installed, and we have confirmed that they do rotate when forward/backward commands are given via the joystick. Despite this, there is no noticeable forward or backward movement of the ROV.
What could be the possible causes of this issue? Any suggestions for troubleshooting would be greatly appreciated.
Have you confirmed the thrusters are all facing and rotating the direction they should? I suspect you may have a setup where the front thrusters are pushing opposite to the back thrusters, so they cancel each other out and there’s no net movement.
If you’re using our standard or heavy BlueROV2 frame (Vectored / Vectored_6DOF) then you can try running the automatic motor reversal detection feature from the BlueOS Vehicle Setup / PWM Outputs page, or the QGroundControl Motors page. If that doesn’t help you can try manually changing the motor reversals individually on one of those pages, or flip the relevant MOTn_REVERSED parameters from a parameter editor.
I’ve experienced a related issue that may be relevant.
On a heavy vectored configuration with four horizontal thrusters, we mounted all horizontal thrusters physically facing the same direction to prioritize forward thrust. All thrusters were verified to behave correctly in Manual mode, including forward and backward movement.
However, when switching to Stabilize mode, the ROV immediately flipped/rolled. We eventually resolved the issue by reinstalling the horizontal thrusters in the physical orientation intended for the selected frame. After doing so, the vehicle behaved normally in all modes.
Sharing this in case physical thruster orientation differs from the standard frame setup.
Hi @SDI -
What you describe should have worked fine, as long as the thruster directions were configured correctly…
A better way to get a speed boost is to install the horizontal thrusters in the holes that angle them at 30 instead of 45 degrees, increasing the component of the thrust in the forwards direction!
Generally any “crazy in stabilize mode” is due to thruster directions being incorrect or thrusters not at the correct location in the frame for the channel number they are connected too…