Development trend: Digital twins accelerate the construction and upgrading of smart cities
(i) Promoted by national policies, many provinces and cities have accelerated the pilot construction
Many ministries and commissions issued policy documents to accelerate the development of digital twin technology, application and industry. "Exploring the construction of digital Twin Cities" was incorporated into the 14th five year plan for national economic and social development and the outline of long-term objectives in 2035 for the first time, providing national strategic guidance for the construction of digital twin cities. The Ministry of housing and urban rural development, the Ministry of industry and information technology The central network information office and other ministries and commissions accelerated the pilot application of the urban information model (CIM) platform and issued a series of standards to guide the construction of CIM infrastructure platforms in various regions. The Ministry of natural resources made great efforts to build a real three-dimensional China and issued the overall plan for the construction of three-dimensional space-time database of natural resources and the technical outline for the construction of real three-dimensional China (version 2021) , clarify the construction task and technical route of real 3D China, and provide a unified space for economic and social development and informatization of various industries.
Shanghai, Zhejiang and other places carried out pilot demonstration to promote the construction of digital Twin Cities Based on CIM. Shanghai has proposed "positioning the urban function in the digital age, strengthening the digital public supply of software and hardware coordination, and accelerating the evolution of urban form to digital twin", and the construction of a pilot digital twin city in Lingang New Area to build a demonstration area of Shanghai's digital transformation. Zhejiang Province released the first pilot list of digital twin construction and applied digital twin technology to ten fields, such as subway safety management and large-scale transportation hub safety management. Shenzhen builds a visual urban space digital platform to explore the "digital twin city". Tianjin proposes to speed up the construction of urban information model (CIM) platform and promote the wide application of CIM platform in urban physical examination, urban safety, engineering management and housing management. Guangzhou speeds up the CIM platform to enable ecological environment, public safety, public transportation, government affairs and justice, so as to realize urban fine and intelligent management.
（2） The formulation of standards has been comprehensively accelerated, and standardization organizations urgently need to strengthen cooperation
Digital twin working groups have been established one after another to become the "main position" leading the standardization of digital twin. Internationally, in November 2020, Digital twins working group of Internet of things and digital twins sub Technical Committee of international organization for Standardization / International Electrotechnical Commission first joint technical committee (ISO / iecjtc1) (sc41 / wg6) was officially established to take charge of promoting the international standardization of digital twins. From China's perspective, the main centralized units for the preparation of National Smart City standards have successively set up new digital twins working groups to lead the construction and development of digital twin cities. The national beacon Commission has established a special group on Urban Digital twins, organized all sectors of industry, University, research and application to carry out basic research and launched urban digital twins standards System framework design. The national general standard committee established a digital twin working group to promote the planning of digital twin technical standard system, the development and application of key standards from the application scenarios and practical needs. The national intelligent Standards Committee has established a BIM / CIM standards working group, which is responsible for developing standards in the BIM / CIM field and organizing research on relevant topics. In addition, the China Institute of information and communications has led the establishment of the digital twin technology application working committee in the China Internet association, jointly with many member units to carry out the formulation of group standards in the field of digital twin, which has become an important force to promote the standardization of digital twin technology application.
The preparation of digital twin standards has entered the first year of development, and a number of key standards have been officially launched. Internationally, sc41 / wg6 is working on two standards: application cases of digital twins and concepts and terms of digital twins, and launched the pre research project of digital twin reference architecture. In China, the National General Standard Committee initiated the project approval of industry standards such as unified identification and coding system of digital twin cities, reference architecture of digital twin cities, technical requirements of urban object model and road digital twin. The national beacon Committee incorporated the urban digital twin standard into a series of information technology standards, and initiated the project approval of standards such as general requirements for digital twin and reference framework for urban digital twin technology. The Ministry of housing and urban rural development and the national intellectual standard committee have promoted the first CIM industry standard in China, the technical standard for urban information model basic platform, which has passed the draft for review. The national landmarks Commission is promoting the project establishment of the basic requirements for real 3D China and the achievement specification of basic geographic entity data. In addition, social organizations such as China Internet association and Beijing Centergate Technologies (Holding) Co.Ltd(000931) smart city industrial technology innovation strategic alliance are actively carrying out research on digital twin city group standards.
