by Kip Hanson
After questioning the hype over Industry 4.0 in last month’s column, I figured I should take a more positive spin this time around by explaining one of the building blocks of smart manufacturing. It’s called the digital twin (or, depending on the software vendor promoting its use, the virtual twin), and as you might suspect from the name, it is a “virtual representation of real-world entities and processes, synchronized at a specified frequency and fidelity.”
That’s according to the Digital Twin Consortium, a group of people who spend their days thinking about these virtual objects and their wide-ranging applications. And although I’ve never spoken with them, I’m certain they would offer a purist definition of the term if asked—one that describes immense benefit to OEMs, less to their Tier suppliers, and virtually none to job shops and contract manufacturers that don’t participate in product design or aftermarket service. Sorry about that.
But what is a digital twin? Consider any piece of capital equipment. It could be a car, tractor, windmill, or CNC machine tool (more on this last example shortly). As one might expect, the digital twin is conceived on a computer that runs the appropriate software platform, be it Siemens’ NX CAD or Dassault Systèmes’ 3DEXPERIENCE or perhaps the Ansys Twin Builder.
Simply put, the digital twin takes the place of a physical prototype or series of prototypes. Every aspect of a product’s design is (or can be) modeled, optimized, tested, manufactured, and applied in a virtual environment. Once the design is approved and its various components put into production, the digital twin will (or can) continue to play a role as information from the manufacturing process is gathered and collected within the twin. And once deployed to the field or sold to the customer, the digital twin might continue to gather real-world usage data from sensors embedded within the actual product, which can then be used for predictive maintenance, failure analyses, and to look for continuous improvement opportunities.
That’s it in a nutshell. If your Haas VF-0 machining centre or Okuma Multus U3000 multitasker has a digital twin—and assuming your shop allows Internet access—the machine builder could easily monitor that equipment from Oxnard, Calif, or Charlotte, NC, respectively, and use the information to give you a heads-up that the spindle bearings are about to fail. They could then update the digital twin accordingly and gain an understanding of how to improve their products. Of course, they might also use the data to determine that the spindle failure was due to a crash or improper machine usage, then tell you the warranty is void. Same goes for your car, tractor, or windmill. Again, sorry about that.
Of course, the use of digital twins extends well beyond the manufacturing space. The Digital Twin Consortium has working groups in infrastructure (think digital bridges, roads, and cities), natural resources (twins of oil wells and solar farms), and even the life sciences (as in digital you and me). And they’re not alone. Check out the websites of the software companies mentioned earlier and you’ll see all manner of digital twin case studies and industry-specific solutions.
As for the job shops and contract manufacturers with “little or nothing to gain” from a digital twin deployment, that’s not especially true. There’s already toolpath simulation (a form of digital twinning), and as Industry 4.0 and the IIoT gain steam, additional opportunities will present themselves. So stay tuned; it’s going to be a wild (albeit virtual) ride. SMT
Technical Editor Kip Hanson has more than 40 years experience in the manufacturing industry. He is the author of Machining for Dummies and Fabricating for Dummies, and has written over 1500 articles (and counting) on a diverse range of topics, among them machining, sheet metal fabrication, 3D printing, automation, software systems, Industry 4.0, and the Industrial Internet of Things
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