Setting <neutrally_buoyant> to 1 sinks the model gradually

[Gowresh7]

I am simulating lauv model in gazebo 9. When I set the tag <neutrally_buoyant>1</neutrally_buoyant>, the lauv model gradually sinks to ground.

[loguna123]

You may have to change the mass, the inertial and the volume tag such that the vehicle is in a state near to neutral buoyant. A PID maybe needed so that the thruster in the simulator will keep the vehicle in position.

[zippyzoo77]

Actually I think this is related to the sensors being attached to the robot having their own mass elements, so even though the robot model is neutrally buoyant, the sensor models are not and thus apply small forces to the robot causing it to sink. I also have this problem with my UUV in the simulator. (I have tested this by commenting out all the sensors, which causes the robot not to sink, but that is not a workable solution, just verification of the problem.)