Quality assurance of digital twins based on mathematical abstraction and tangle-based blockchain architectures

自上个世纪末以来，数字孪生概念已经成熟为许多工程学科的重要基石。然而，由于土木工程结构的独特特性，土木工程中的数字孪生兄弟通常是针对特定的用例或特定的结构子系统(如结构子系统、机械子系统)量身定做的。由于数字双胞胎在土木工程中的独特性、复杂的通信网络以及组成数字双胞胎的接口和模型的异构性，导致缺乏互操作性和客观的质量保证策略。为了提高数字双胞胎的质量，充分挖掘数字双胞胎在土木工程中的潜力，需要对数字双胞胎的语义结构有清晰的数学理解，这将为数字双胞胎的质量保证(包括一致性检查、验证和确认)提供正式的概念。拟议的项目旨在提供一种方法，在所有设计阶段以及设计阶段将经过的所有抽象级别--从创建抽象的概念模型到实施具体的实际应用--实现数字双胞胎的可靠质量保证。在拟议的项目中，重点放在基础设施的数字双胞胎上，尽管该项目提出的所有方法都将普遍适用。首先，将对数字双胞胎的分类表示进行领域分析，以适当地描述与数字双胞胎相关的概念和实体。接下来，工作计划致力于三个层次的抽象。在每个层面上，将提出(I)建模概念和(Ii)这些建模概念的质量保证方法。建模概念将结合基于关系代数、分类本体协议和类型理论的抽象数学方法(“元-元建模”)、工程师容易理解的图解语义(“元建模”)以及在数值分析和建筑信息建模中建立的工程模型(“建模”)。质量保证的方法本质上是基于抽象的数学描述、基于效用的指标和基于纠缠的区块链架构，引入这些架构是为了在数字双胞胎的生命周期内验证它们。预计对数字双胞胎的语义结构的数学理解将被形式化。在此基础上，进一步期望为土木工程中的数字孪生兄弟提供客观可验证和普遍适用的语义建模概念，作为各级抽象的质量保证的基础。在早期设计阶段将避免建模错误，数字孪生兄弟的实施将是有效和独立于技术的，为提高民用基础设施数字孪生兄弟的质量提供了可行的基础。

The digital twin concept has matured into a crucial cornerstone of many engineering disciplines since the end of the last century. Digital twins in civil engineering, however, are usually tailored to specific use cases, due to the unique character of civil engineering structures, or to specific subsystems of structures (e.g. structural subsystem, mechanical subsystem). The uniqueness of digital twins in civil engineering, the complex communication networks, and the heterogeneity of interfaces and models comprising the digital twins result in a lack of interoperability and objective quality assurance strategies. To improve quality and fully exploit the potential of digital twins in civil engineering, a clear mathematical understanding of the semantic structure of digital twins is required, which will provide formal concepts for quality assurance (including consistency checks, verification, and validation) of digital twins. The proposed project aims to provide a methodology to enable reliable quality assurance of digital twins in all design phases and at all levels of abstraction from which the design phases will pass – from creating abstract, conceptual models to implementing specific, practical applications. In the proposed project, the focus is placed on digital twins for infrastructure, although all approaches proposed in this project will be generally applicable. First, a domain analysis for taxonomic representation of digital twins will be performed to appropriately describe concepts and entities relevant to digital twins. Next, the work program is devoted to three levels of abstraction. On each level, (i) modeling concepts and (ii) approaches towards quality assurance of these modeling concepts will be proposed. The modeling concepts will couple abstract mathematical approaches based on relational algebra, categorical ontology protocols, and type theory ("meta-metamodeling"), diagrammatic semantics that are easily comprehensible by engineers ("metamodeling"), and engineering models established in numerical analysis and building information modeling ("modeling"). The approaches towards quality assurance are essentially based on an abstract mathematical description, utility-based metrics, and a tangle-based blockchain architecture, introduced to validate the digital twins during their lifetime. It is expected that a mathematical understanding of the semantic structure of digital twins will be formalized. On this basis, it is further expected that objectively verifiable and generally applicable semantic modeling concepts for digital twins in civil engineering will be provided, serving as a basis for quality assurance at all levels of abstraction. Modeling errors will be avoided in early design phases, the digital twin implementation will be efficient and technology-independent, entailing a viable basis for increasing the quality of digital twins for civil infrastructure.