Research on multi-scale modeling method for digital twin workshop with considering multi-levels, domains and dimensions

Digital twin(DT) has been widely recognized as the key technology for the fusion of virtual-real space to promote the digitalization and intelligence of manufacturing industry. As a typical sophistication production system, the workshop involves multilevel, multi-domain and multi-dimension scales, reflecting the spatial assembly constraints, domains interaction coupling, and the function and structure characteristics of all elements. However, most research about workshop digital twin modeling involves various types of models and tools, resulting in model problems such as high complexity, low integration and manageability, and the most of current model only focuses on a single scale, ignoring its multi-scale features and the corresponding association relationships between different scale models. To solve the above issues, this paper proposes a multi-scale modeling method for digital twin workshop integrating the multi-level, multi-domain, and multi-dimension scales. Firstly, the multi-scale model framework is proposed, and the hierarchical model tree is represented, showing the multi-scale compositions of the workshop and the relationships between different scales. Then, the multi-level, multi-domain and multi-dimension modeling methods, mainly based on the unified modeling languages, are studied respectively. Finally, a gearbox production workshop is chosen as the case to validate our proposed methodology. In conclusion, this paper provides a clear, logical, and procedural approach to guide the construction of multi-scale digital twin model for highly complex production system in a unified and standardized way.