The application and development of digital twin in the marine domain

Abstract

With the gradual shift of marine resource development towards large-scale and deep-sea exploration, traditional analytical and simulation techniques are no longer able to meet the growing demands of users. Digital twin (DT) technology offers a potential solution to address these challenges in the marine domain. This study focuses on DT technology for marine applications, providing a detailed discussion on the concept, application framework, key technologies, and future developments in the marine DT (MDT) field. A systematic review of relevant literature on MDT was conducted using the Web of Science database, analyzing the research focuses within this field. This study proposes a definition for MDT and presents a five-layer application framework, including the perception layer, data layer, model layer, fusion layer, and application layer. Key technologies for MDT are summarized, with a particular emphasis on data collection and transmission, data storage and management, modeling and simulation, and monitoring analysis and evaluation techniques, along with their applications in the marine domain. The future prospects of MDT are discussed, and the construction and application of a DT platform are demonstrated using marine engineering as an example. Furthermore, potential challenges in the development of MDT are analyzed, and possible solutions are proposed. The ocean covers approximately 360 million km 2 , accounting for 71% of the Earth's surface [1]. It contains about 1.33 billion km 3 of water, harboring more than 80 chemical elements and 200,000 marine species [2]. With its abundant resources, including minerals, biology, water, energy, and space, the ocean has become a vital area for economic development and scientific advancements. Utilization of the ocean encompasses activities such as marine resource exploitation, marine spatial utilization, marine energy utilization, coastal protection, marine construction, and exploration. Taking marine engineering as an example, it can be broadly divided into two main components: resource development techniques and infrastructure facilities. Marine engineering can be categorized into coastal engineering, offshore engineering, and deep-water offshore engineering based on the areas of utilization. Marine engineering must withstand various natural elements such as seawater corrosion, marine organism attachment, earthquakes, typhoons, waves, tides, currents, and sea ice. Shallow coastal areas also require addressing beach evolution and sediment transport. As marine-related technologies advance, marine engineering is evolving towards larger-scale and deep-sea exploration. For instance, in 2017, China International Marine Containers (Group) Co., Ltd. constructed the Blue Whale I, a semi-submersible drilling platform. The platform measures 117 m in length, 92.7 m in width, 118 m in height, weighs 44,000 t, and has a maximum operating water depth of 3658 m and a maximum drilling depth of 15,250 m. In 2023, China State Shipbuilding Corporation Limited developed the H260-18MW offshore wind turbine, setting records for power and rotor diameter. The rotor sweep area is approximately 53,000 m 2 , equivalent to the size of seven standard football fields. Consequently, the construction challenges of such projects have increased, along with management risks related to costs, safety, and operation and maintenance. The complex and difficult-to-describe nature of the marine environment poses challenges to the further development and utilization of the oceans. The concept of "transparent ocean", proposed by Academician Lixin Wu, refers to the real-time or near-real-time acquisition and assessment of marine environmental information at different spatial scales in specific marine areas. It aims to study the multi-scale changes and climate resource effect mechanisms and, based on this, predict the spatiotemporal variations of marine environment, climate, and resources within a specific period, making the ocean "transparent". The concept of "transparent ocean" encompasses transparency of state, processes, and changes, and its realization involves integrated research in observation, cognition, and prediction. However, challenges arise in high-precision monitoring of marine environmental information and the inconsistent format, structure, spatial division, time intervals, and accuracy of numerous marine environmental datasets. This hinders data correlation, coordination, and deep-level application of data-driven analytical models. Therefore, integrating