Unity Prevent Objects from Intersecting

Okay I have a robot arm in which the rotations are controlled by a joystick inputs. One issue is The arm can currently intersect (go through) with other parts of itself. What might be the best approach to prevent this intersection?

For example of how it is set up, I have a base which can rotate around the z axis and the other pieces of the arms are children of the base respectively. Each piece rotates as needed by the controller...whats happening is there are other pieces to the robot that the arms intersect with or rotate right through....I want to be able to prevent the base from rotating when it detects this object, but I still want to rotation to be live so I can rotate the opposite directions.

I've tried rigid bodies, but this stops the arm from going through, but the base still keeps rotating and the arm goes out of position.

Any help/insight is appreciated.