Section: New Results

Multi-modeling and co-simulation

Participants : Laurent Ciarletta [contact] , Olivier Festor, Ye-Qiong Song, Yannick Presse, Victorien Elvinger, Julien Vaubourg, Alexandre Tan, Benjamin Segault, Emmanuel Nataf.

Vincent Chevrier (former Maia team, Dep 5, LORIA) is a collaborator and the correspondant for the MS4SG project, Benjamin Camus, and Christine Bourjot (former MAIA team, Dep 5, LORIA) are collaborators for AA4MM/MECSYCO. Julien Vaubourg's PhD is under the co-direction of V. Chevrier and L. Ciarletta.

In Pervasive or Ubiquitous Computing, a growing number of communicating/computing devices are collaborating to provide users with enhanced and ubiquitous services in a seamless way.

These systems, embedded in the fabric of our daily lives, are complex: numerous interconnected and heterogeneous entities are exhibiting a global behavior impossible to forecast by merely observing individual properties. Firstly, users physical interactions and behaviors have to be considered. They are influenced and influence the environment. Secondly, the potential multiplicity and heterogeneity of devices, services, communication protocols, and the constant mobility and reorganization also need to be addressed. Our research on this field is going towards both closing the loop between humans and systems, physical and computing systems, and taming the complexity, using multi-modeling (to combine the best of each domain specific model) and co-simulation (to design, develop and evaluate) as part of a global conceptual and practical toolbox.

We proposed the AA4MM meta-model [76] that solves the core challenges of multimodeling and simulation coupling in an homogeneous perspective. In AA4MM, we chose a multi-agent point of view: a multi-model is a society of models; each model corresponds to an agent and coupling relationships correspond to interaction between agents. In the MS4SG (Multi Simulation for Smart Grids) projet which involves some members of the former MAIA team, Madynes and EDF R&D on smart-grid simulation, we developed a proof of concepts for a smart-appartment case that serves as a basis for building up use cases.

In 2015 we worked on the following research topics:

• Assessment and evaluation of complex systems.

• Cyber Physical Systems

  We have led the design and implementation of the Aetournos platform at Loria. The collective movements of a flock of flying communicating robots / UAVs, evolving in potentially perturbed environment constitute a good example of a Cyber Physical System. Applying co-simulation technique we plan to develop a hybrid "network-aware flocking behavior" / "behavior aware routing protocol".

  We have provided a working set of tools: multi-simulation behavior / network / physics and generic software development using ROS (Robot Operating System). The UAVs carry a set of sensors for location awareness, their own computing capabilities and several wireless networks.

  The effort put in the UAVs gathers academic and research ressources from the Aetournos platform, the R2D2 ADT and the 6PO project, while applied, industrial and more R&D projects have been pursued this year (Outback Joe Search and Rescue Challenge, Alerion, Hydradrone) .

• MS4SG to link multi-simulations tools such as HLA (High Level Architecture) and FMI (Functional Mockup Interface) thanks to our AA4MM framework. We have so far successfully applied our solution to the simulation of smart apartment complex and to combine the electrical and networking part of a Smart Grid. The AA4MM software has seen major improvements in 2015 thanks to the ressources provided by the MS4SG project and a Carnot engineer financed thanks to Inria. It has been renamed as MECSYCO (http://www.mecsyco.com ).

  Starting from domain specific and heterogenous models and simulators, the MECSYCO suite allows for multi *systems* integration at several levels: conceptual, formal and software. A couple of visualization tools have been developed as proof of concepts both at run-time and post-mortem.

  We have developed software components and plugins that interconnects within MECSYCO heterogeneous simulators from different domains: FMU (working with the 1.0 and 2.0 FMI standard for CoSimulation) ou non-FMU such as NS3 or Omnet++.

  Several EDF oriented use cases have demonstrated multi-simulations.

In additon to technical reports, several publications have been accepted in 2015 on these subjects [51] , [49] and [48] .