In Stay Sharp Episode 87, Digital Twin Use Cases, co-hosts Jonathan Scott and Juliann Grant are back with a new topic in Razorleaf’s series on digital twins. This time, they’re discussing concrete examples of twins of all kinds in physical, virtual, and even cinematic form. Their returning guest is Dr. Patrick Hillberg, who has decades of experience in PLM digitalization and advanced manufacturing. The trio cover real-life situations and explain the twins behind them.
Front-Running Simulation Twins
Possibly the most accessible example of what a twin is and why it’s useful comes from the movie “Apollo 13” (1995). In a particular scene, pilots and engineers on the ground in Houston use a physical replica of Apollo 13’s command module and lunar module to determine how the pilots in space could restore power to the command module after an oxygen tank explosion crippled the spacecraft. “They had a physical twin,” Patrick says. “They had this physical thing that could emulate what was going on up in the capsule.” That’s one of the drivers of digital twins, Jonathan notes, “a low-risk environment to try things out.” Patrick describes the Apollo 13 twin as a “front-running simulation,” doing the simulation before the action needs to occur in real life. Originally built for training, the “aha” moment, Jonathan says, was realizing it could be used to fix an emergent problem they weren’t prepared for.
Another example of twins that enable testing ahead of time is an incident involving a harbor crane that collapsed from trying to lift too much weight. Patrick says, “a front-running simulation could have guided the people on board in terms of the lift that they were actually making. The Apollo 13 case is let’s simulate this whole thing in advance … the Atlantic Giant [crane] was, let’s simulate this a few seconds in advance, so we can recognize and we can throw up warning flags or potentially stop.” A real-time simulation can provide situational awareness of the system and potentially also prevent disaster.
Digital Twins With Feedback
Other digital front-running simulation twins could involve feedback from the physical to the digital, based on sensors or strain gauges attached to a structure. That twin could predict or warn of a bridge crack growing and endangering the structure’s integrity. Especially if the strain gauge is tied to a finite element analysis (FEA) model, based on original 3D geometry, Patrick says, “We could recognize in advance that the bridge either needs to be closed or the bridge needs to be repaired.” With the same sensors providing feedback to a digital model, the eventual collapse of a Florida apartment building might have been predicted years or months in advance—or at the very least, detected a few minutes prior so a fire alarm could be sounded to get residents out in time.
An example of a full digital twin with information flowing bidirectionally between the virtual and the physical is a phone application that allows you to control aspects of your car—such as locking it remotely when Patrick recently forgot to do so. “It’s a sparse model. I mean, it only gives me six or seven pieces of information, but that was a really important piece of information,” Patrick admits.
The Relationship of Threads and Twins
In 2011, Dr. Michael Grieves defined six characteristics of PLM in Virtually Perfect. Pat sees those as accurate, but for describing digital threads and twins. Two of them describe digital twins, he feels, “But the foundation of all this is the other four, which is the digital thread. The digital thread becomes the real technological thing. If our goal is to have a virtual model of anything that exists in the real space, what is that technology that gets us there?” Juliann summarizes, “The thread is really the feeder of data into a twin.”
People tend to think about what they need digital twins for. To get it, you might have to work backward to design a digital thread, that is, to assemble your underlying set of connected data that will enable the twin. Patrick concurs, “If you begin with a concept that the information is actually to some extent more important than the product—they have to work together, but every bit as important as the product—you begin by designing and developing your digital thread and then come back and start building the product on top of that.”
Learn More About Where Digital Twins Can Help Your Organization
The full podcast contains more discussion and details on a variety of topics, including more details on the six characteristics of PLM/threads/twins, how digital twins can help us prevent airline crashes and loss of lives, what the Swiss cheese model of safety is about, and more.
Be sure to check out Stay Sharp Episode 87: Digital Twin Use Cases and join us each week for a new podcast.
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