An Approach to Develop Collaborative Virtual Labs in Modelica

Virtual labs are valuable educational resources in control education, and are widely used in the process industry as tools for operator training and decision aid. In these application domains, virtual labs typically rely on the interactive simulation of large-scale hybrid-DAE models with components of different engineering domains, whose description can be greatly simplified by the use of the Modelica language. Existing free and commercial Modelica libraries of different domains can be used to describe these models. The Interactive Modelica library facilitates developing virtual labs based on Modelica models, using only Modelica. A new major release of the Interactive Modelica library is presented in this paper, whose most relevant feature is to facilitate the implementation of collaborative virtual labs written using only the Modelica language. This library can be used with the environment OpenModelica, facilitating the implementation of cooperative virtual labs using only open software. This type of virtual lab, which allows several students to interact cooperatively with the same model simulation run, is an effective tool in the context of collaborative learning methods. The efficient communication among the graphical user interfaces and the simulation model is a key issue. We developed a new communication protocol, a synchronization algorithm, and redesigned the Modelica classes of the library to make the communication completely transparent to virtual lab developers. The implementation of a collaborative virtual lab for process control education, based on a simplified version of the Tennessee Eastman process, is discussed. The Interactive Modelica library is freely distributed under Modelica License 2 and can be downloaded from http://www.euclides.dia.uned.es/Interactive