How to get an object to return to a "resting" orientation?

Hello, I beleive I have a simple question: I am making an underwater robot simulator, when the player hits an object, the robot is pitched. Is there a relatively easy way to make it so that the robot "self rights" back to floating level when it is no longer forced against the object?

Long story short, I need a way to get an object to constantly try to go to a certain orientation, but still allow objects to bump it off.

Or if their is a way to read the current orientation of an object, that will work for me too. :)

Thank you, and have a wonderful day! -Gloop