A systematic review of digital twin about physical entities, virtual models, twin data, and applications.

• The definition, characteristics, and application areas of the digital twin are clarified. • The types and methods of physical information acquisition are summarized. • The general steps of virtual model construction based on the virtual model paradigm are presented. • The methods of twin data acquisition and data exchange protocols are summarized. • The application areas of digital twins are divided into three phases. The digital twin is a crucial technology for realizing smart manufacturing and industrial digital transformation, which has received extensive attention and research from industry and academia. After 20 years of development, the application area of digital twins has been pervasive. Due to the diversity of application areas, various reference models and research methods have been presented for the components of the digital twin. Therefore, this paper provides systematic research of current studies on the basic components of the digital twin. This paper analyzed 117 articles from 2017 to 2022. By clarifying the relationship between the digital twin and the cyber-physical system, it first clarified the definition, characteristics, and application areas of the digital twin. On this basis, the research methodology of the core components of the digital twin (physical entities, virtual models, and twin data) is analyzed. At the same time, the application areas of digital twins are analyzed and delineated, and the application potential of the digital twin is explored. Finally, the research results and future research recommendations are presented. [ABSTRACT FROM AUTHOR]