数字孪生及其在航空航天中的应用

数字孪生已引起国内外的广泛重视，可看作是连接物理世界和数字世界的纽带。其通过建立物理系统的数字模型、实时监测系统状态并驱动模型动态更新实现系统行为更准确的描述与预报，从而在线优化决策与反馈控制。本文分析表明数字孪生体相比一般的模拟模型，具有集中性、动态性和完整性的突出特点。数字孪生的发展需要复杂系统建模、传感与监测、大数据、动态数据驱动分析与决策和数字孪生软件平台技术的支撑。在航空航天领域，数字孪生可应用于飞行器的设计研发、制造装配和运行维护。重点讨论了应用机身数字孪生进行寿命预测与维护决策的案例，相比于周期性维护，具有检修次数更少、维护成本更低的优势。最后，给出了数字孪生在空间站、可重复使用飞船的地面伴飞系统中的初步应用框架。

Digital twin and its aerospace applications

Digital twin, the link between the physical and digital worlds, has currently attracted extensive attention both at home and abroad. Through establishment of a digital model of a physical system, real-time monitoring of the system status, and driving of the dynamic model update to describe and forecast system behaviors more accurately, the online decision optimization and feedback control are realized. In this paper, analyses show that compared with a general simulation model, the digital twin has outstanding characteristics of being centralized, dynamic, and integral. The development of the digital twin requires the support of complex system modeling, sensing and monitoring, big data, dynamic data-driven analysis and decision, and software platform technology. In the field of aerospace, digital twin can be applied to the design, development, manufacturing, assembly, operation and maintenance of aircraft. This article focuses on a case of application of the airframe digital twin to life prediction and maintenance decision, which exhibits advantages of lower maintenance frequencies and maintenance costs compared with the periodic maintenance. Finally, a preliminary application framework of a ground accompanying flight system established for space stations and reusable spacecraft is demonstrated.