The RobMoSys project makes available a baseline of already existing metamodels. They sufficiently conform to the RobMoSys composition structures. For example, the SmartMARS metamodel form the The SmartSoft World and also metamodels in the Papyrus4Robotics World.
In the course of the project, RobMoSys is going to provide an Ecore implementation of the RobMoSys structures. RobMoSys Structures: Realization Alternatives describes this in more detail and also lists alternatives.