Biblio

Digital-Twins simulate physical world objects by creating 'as-is' virtual images in a cyberspace. In order to create a well synchronized digital-twin simulator in manufacturing, information and activities of a physical machine need to be virtualized. Many existing digital-twins stream read-only data of machine sensors and do not incorporate operations of manufacturing machines through Internet. In this paper, a new method of virtualization is proposed to integrate machining data and operations into the digital-twins using Internet scale machine tool communication method. A fully functional digital-twin is implemented in CPMC testbed using MTComm and several manufacturing application scenarios are developed to evaluate the proposed method and system. Performance analysis shows that it is capable of providing data-driven visual monitoring of a manufacturing process and performing manufacturing operations through digital twins over the Internet. Results of the experiments also shows that the MTComm based digital twins have an excellent efficiency.

In the development process of critical systems, one of the main challenges is to provide early system validation and verification against vulnerabilities in order to reduce cost caused by late error detection. We propose in this paper an approach that, firstly allows formally describe system security specifications, thanks to our suggested extended attack tree. Secondly, static and dynamic system modeling by using a SysML connectivity profile to model error propagation is introduced. Finally, a model checker has been used in order to validate system specifications.