emerge/dive cause rotation

[19gearloose97]

Hi guys

I successfully build my ROV, reaching 100m depth.
My ROV has 3 motors, two horizontal and one vertical
When use vertical for dive\emerge the ROV rotates.
Does anyone experience that problem?
I did an internet search and I didn't found anything, like no one has deal with that problem
I'm thinking addind a tail (vertical) to somehow create a resistance.

[Kale]

I had the same problem. Now I'm rebuilding my rov with two vertical thrusters. One right and one left propeller.

/Kale

[FJM]

My ROV is still in the conceptual phase, so I not talking from underwater experience. However, helicopters have the same issue which I know a bit about.

When the rotor/vertical prop turns one direction the copter/ROV will tend to turn the opposite. Copters have a tail rotor to counteract this rotation. If you have speed control over each motor, you might be able to add a bit of thrust to one motor to counteract the rotation when the vertical prop is turning. You'd need to add a bit to the other thruster instead when the prop turns in the opposite direction. This would be easy to do if your motors are controlled by a microprocessor that you can program.

The amount you need to add would depend on the torque of the vertical thruster.

Since the prop may perform better when going forward over reverse, the amount you need to add may be different as well when ascending vs descending.

Fred

[19gearloose97]

Thanks for your answers, I'm using openrov hard/software. So its a bid difficult to intervieen the code or add thruster. I'm trying hardware methods for the begining.
I'm thinking putting the vertical thruster in the back of the frame and add a small piece of metal to change the fault direction, or give some decrease the thruster it self to the left.
But the better solution is to make changes by software if use a microcontroller.
Fred I can help you with the frame, just pm me when you are at this point.