May 2023 Volume 5

AUTOMATION

Digital Twins A New Tool in the Forger’s Kit By Dean M. Peters

A decades-long digital twin technology is making headway into a millennia-long industry. A digital twin can be a virtual model of an existing process, or a design tool to help design a new process or production line. Through real- or near-time communications with an actual process, the digital twin can help regulate production, control quality, prompt maintenance activities, and generally improve manufacturing efficiency. The concepts of Metamorphic Manufacturing and Robotic Blacksmithing are also discussed.

In 1991, David Galernter, a professor of computer science at Yale, published a book called Mirror Worlds in which the concept of digital twins was foreshadowed. It took another eleven years before the concept and model of digital twins was presented at a Society of Manufacturing Engineers meeting by Michael Grieves, then a faculty member of the University of Michigan. Still, it would be eight more years before the term “digital twin” would be introduced by NASA’s John Vickers in 2010. Thusly, the digital twin concept was born and named. Since

then, the concepts and technological interrelationships, aided by the evolution of the Internet of Things (IoT) and refinements in computer simulation technology, have enabled the digital modeling of real-life systems. The full digital modeling of physical systems can yield performance data in real time, which offers the ability to immediately respond to changes in the environment in which the systemoperates. Conversely, by using digital twin technology, better physical systems can be designed by using the predictive nature of digital models, within which various input parameter values can be ‘tried out’ before building a physical system.

First published figure to illustrate a Digital Twin Model. Courtesy of Creative Commons Attribution-Share Alike 4.0 International

There are many ‘definitions’ of digital twins, depending on which sources you consult, but for the purposes of this article we use a simple one, upon which there are variants: A digital twin is a virtual representation of an actual physical product, system, or process. In this article, our primary interest is how digital twins can apply to manufactured products or in manufacturing settings. As a matter of scale, digital twin technology can be applied to the manufacture of a single forged part for a wind turbine, a single operational wind turbine or a the operation of an entire wind farm. In an irony that would make the zodiacal Gemini twins Castor and Pollux grimace, the digitization of an existing system using digital twin technology has three components. These include the physical system and its environment that are being modeled, the digital

twin itself, and the communications (sometimes in real-time) that exist between the actual system and the digital twin. This two-way flow of information is called the digital thread. As the digital twin receives information from sensors on the physical system, the data can be used to study the system’s performance and devise ways in which it can be improved. Any promising improvements can be ‘tried’ digitally on the twin and then be implemented. In a different context, the term digital thread can also describe the complete history of a part or product through its lifecycle. According to the Boston-based Digital Twin Consortium (DTC), on their manufacturing web page, “Digital Twins are being used to manage the performance, effectiveness, and quality of manufacturers' fixed assets such as manufacturing machines, lines,

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