A digital twin-based approach for the management of geometrical deviations during assembly processes

Abstract

The recent transformation in the aeronautical industry gives new prospects in the field of product geometry assurance. These include, in particular the creation of sophisticated virtual models, or digital twins, which can reflect the as-built geometry of physical products and optimize the assembly operations consequently. One of the current obstacles to the implementation of such digital twins is linked to the difficult transition from a conceptual model to a usable virtual representation. In this article, we present the hybrid representation of a product which is capable of integrating the different states of the components at each step of the assembly process. We propose a method to update the virtual representation of already assembled components, in order to include the position and orientation deviations of their surfaces. The B-Rep model of each component is updated from data acquired during the assembly of the product. The various steps of this update, and its associated tools are discussed in the article. Based on the knowledge of the as-built component geometry, the geometry of the yet-to-be-assembled components is adapted so that the final product complies with the functional requirements. To this end, we also discuss a formalism to model the product's functional information and to translate it at a geometrical level thanks to an assembly skeleton.

A Data-Driven Methodology to Improve Tolerance Allocation Using Product Usage Data

“…Since the tolerance reflects the variation of geometric constraint between two features, based on the above definition, the tolerance in assembly is classified into three classes [13]. The first is selfreference tolerance.…”

“…It could handle different types of variation and contribute to robust design. Grégorio et al [13] proposed a digital twin based method of geometrical deviation management, which updates the virtual representation of parts during assembly. The present work focuses on the tolerance allocation improvement under the cyber-physical system (CPS) background.…”

“…They could be seen as a random variable with a normal distribution. After knowing their lower and higher limits (intervals), 3 σ criterion is used to calculate its mean value and variance [13].…”

“…We assume deviations have a normal distribution. After knowing the intervals of FRs, 3σ criterion is used to calculate its mean value and variance [13]. Then the missing labels are predicted by feeding the actual measured data in this HGAT model.…”

Research Status, Key Technology and Its Application Prospect of Complex Products Assembly Quality Control and Prediction Based on Digital Twin

“…With the development of computer aided design and computer aided manufacturing technology, the assembly tolerance analysis method based on skin model shape has been widely used in the eld of product assembly tolerance analysis [31][32][33][34], and has achieved satisfactory results. In recent years, with the rapid development of digital twin technology, many scholars and researchers have proposed a geometric deviation management method based on digital twin in the product assembly process [35,36], this method of simulating the whole assembly process has achieve accurate analysis and prediction of assembly errors through the interactive fusion of real physical model and high-delity virtual model, and provided a theoretical basis for improving the stability and quality of product assembly. In assembly stress analysis, the generated stress by the assembly process not only seriously affects the structural stability of the mechanical system, but also plays a crucial role in the assembly accuracy and reliability of the mechanical system.…”