The role of surrogate models in the development of digital twins of dynamic systems

• Published in: Applied Mathematical Modelling Vol. 90; pp. 662 - 681
• Main Authors: Chakraborty, S., Adhikari, S., Ganguli, R.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Inc 01-02-2021; Elsevier BV
• Subjects: Aerospace industry; Digital twin; Digital twins; Dynamical systems; Emulators; Frequency; Gaussian process; Mathematical models; Response; Stiffness; Surrogate; Vibration; Response; Frequency; Vibration; Digital twin; Surrogate
• ISSN: 0307-904X; 1088-8691; 0307-904X
• DOI: 10.1016/j.apm.2020.09.037

•A Gaussian process surrogate of a digital twin of a discrete damped dynamic system model is proposed.•The concept of “slow time” is proposed to differentiate the evolution of the digital twin from its “real time” dynamics.•Functional variation of stiffness and mass in the discrete system is considered.•Sensor errors are modeled in the update process of the digital twin surrogate.•Effect of data quality and sampling rate on the Gaussian process surrogate is evaluated.
Digital twin technology has significant promise, relevance and potential of widespread applicability in various industrial sectors such as aerospace, infrastructure and automotive. However, the adoption of this technology has been slower due to the lack of clarity for specific applications. A discrete damped dynamic system is used in this paper to explore the concept of a digital twin. As digital twins are also expected to exploit data and computational methods, there is a compelling case for the use of surrogate models in this context. Motivated by this synergy, we have explored the possibility of using surrogate models within the digital twin technology. In particular, the use of Gaussian process (GP) emulator within the digital twin technology is explored. GP has the inherent capability of addressing noisy and sparse data and hence, makes a compelling case to be used within the digital twin framework. Cases involving stiffness variation and mass variation are considered, individually and jointly, along with different levels of noise and sparsity in data. Our numerical simulation results clearly demonstrate that surrogate models, such as GP emulators, have the potential to be an effective tool for the development of digital twins. Aspects related to data quality and sampling rate are analysed. Key concepts introduced in this paper are summarised and ideas for urgent future research needs are proposed.