The Birth of the Digital Twin
Giving machines an identity
“Smart” Products
We hear a lot of talk about “smart products” in Industry 4.0.
But how does one start giving “intelligence” to a machine or asset?
Give it an identity!
The basis for every”thing” in the Internet of Things is the working connection to a common network. But as of today, many machines have no possibility to communicate their identity. This is one of the main hurdles to bring Industry 4.0 to be productive.
So, one of the first actions in making products „smart“ is giving them a digital identity. The common industry term is the “digital twin”. A virtual counterpart to a physical object.
“Things will be represented by digital twins, a dynamic software model of a physical thing or system.” (Gartner)
But, a lot of effort has to flow into the “birth” of the digital twin. Good thing, there are steps you can take to take your product from “zero to twin”.
This post gives an overview of these steps to connect physical and virtual world. Plus, short examples how the real application could look like.
1) Digital fingerprint
A human fingerprint contains information. Not a lot, but enough to identify the person behind it.
A machine’s digital fingerprint also conveys only one small piece of information. This information is static and immutable. And it allows for a unique identification of the asset.
As a first step, the asset gets an identifier (ID) as it leaves assembly.
The ID and asset information gets logged in the manufacturer database. It can include basic product information as well.
Examples include the name of manufacturer and assembly date.
Application example
The operator in front of the machine uses his cell phone to scan the attached QR code.
His browser leads to a unique website, hosted by the equipment manufacturer.
It shows all the information about the real asset.
The list includes the unique serial number and manufacturing date. Also, the exact bill of materials and spare parts are listed. Attached PDF files contain the operating manual and repair instructions.
Benefits
- No need to investigate paper manuals or the manufacturer website.
- The operator has access to the basic asset information.
- Asset identification and information about basic properties.
- Tasks and spare part information for the maintenance crew.
2) Digital snapshot
A snapshot, in the common sense, is a static piece of information. It shows detailed information about the real object at a certain moment. Pushing the shutter button updates the information.
The digital snapshot of an asset allows manual updates to the online asset information.
An operator can do this during the complete lifetime of the machine.
Application example
The scan of the QR code opens the web page for the individual asset. The maintenance expert can now update the asset information.
The updates can feed the individual service history. The maintenance job archive can contain relevant information, such as:
- Date, timestamp
- Cycles run (like total kilometer/miles run of a car)
- Maintenance job performed
- Spare parts used
- Time for maintenance
Benefits
- Shows the complete service history.
- Up to date asset information accessible online.
- Closes the communication gap between maintenance professionals.
- Effectively reduces their time to plan and carry out machine servicing.
! But it requires discipline of the users to update the information in a flawless format.
3) Digital shadow
The next level aims to rule out human influence in the collection and update of information.
A shadow shows an always current 2-dimensional projection of the object. Its shape and behavior are bound to the real movements of the physical counterpart.
The digital fingerprint and digital snapshot can only convey static information. But a digital shadow sends the information about the product automatically to the database.
Information can include:
- Design
- Configuration
- Condition or status
- Location
- Statistics
So the user can access the most current information about the object properties.
A first use is already the manufacturing of the physical IoT product itself. An asset's digital shadow is created in product design. It can then guide and steer the assembly workflow.
Application example
A connected machine automatically uploads every tooling change, all production data and every parameter change. So the operator can exactly understand the current state and history of the machine.
Benefits
- No extra effort for the operator.
- No risk of false or incomplete entries in the asset information.
- Easier asset assembly planning
4) Digital twin
Now we’re talking the full blown solution — the “exact” digital copy of an object (“exact” is as vague as it is utopic). And what is regularly listed in the Industry 4.0 vision.
The asset information now contains with the underlying machine behavior as well. It describes how the object is expected to behave based on a set of input parameters.
This enables:
- Virtual planning and analysis
- Simulation of outcomes without interfering with the ongoing production
Application example
A virtual tooling change shows whether the cutting tool needs replacement. This ensures a high quality production output. It also shows how much longer the current cutting tool can be used.
Benefits
- Production simulations are possible.
- This reduction of trial and error activities.
- Less effort to set up and optimize the process.
- Better planning of maintenance jobs.
Final considerations
- What would be the value to an application of any of these steps to your product and organization (Value first, people!)? Less complex IoT products might not be worth the effort of fully digitizing. Also, the convenience of the solution for the user needs to be considered.
- For complicated machines, it might not be clear what the individual object is. So what gets treated as an individual object and assigned an ID?
- If you decided what to achieve, you will determine which kind of architecture is suitable. Options include Cloud, private Cloud, on-premise, on-asset. Also how will the user get to the digital counterpart of the asset (RFID, QR)?
- High value information needs high security data transportation and storage. The digital fingerprint could point towards an open web page (uncritical information). The high-end digital twin needs to be fully access controlled (mission critical information).
Daniel Sontag connects the bots: As Industry 4.0 lead and manager for connected products, he does what he loves — tying business to tech, and theory to practice.
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