Shades of Digital Twinning
Standards for software versioning and life-
cycle management are few, but OSGi 2 stands
out as a well-defined standard modular
framework for this. When used with real-
time Java, OSGi could also be used for
control applications. It is already an element
of some gateway and home automation
systems. Since communication can be
modularized, it also reduces the cost of
switching protocols. This might be a good
standard for the device shell.
monitor them. Connectivity brings the ability
to compare and contrast what a model
would predict with the actual physical
behavior of the device. This increases both
the value and accuracy of simulation models.
But digital twinning is defined more broadly
than just a simulation model. Even within
simulation, there is more than one way to
simulate something.
Devices and their twins are largely
recognized as the workhorses that have
simplified the creation of an IoT system 3 ;
however, the definition of digital twin is not
very precise. Digital twin has become the
popular, widespread catchall for the digital
representation of a physical asset. This
ambiguity has been compounded by the
intertwining
of
the
term
“Asset
Administration Shell” 4 with that of “Digital
Twin.” While digital twin has simplified
complex parts of the IoT, the myriad
interpretations and definitions of very
distinct architectures are compounding
ambiguity of the term. There is a need to
refine the meaning of both terms, or at least
subdivide them into more useful categories
for reasoning about edge or fog computing.
The goal is to provide a better definition for
bridging the gap between OT and IT.
Data exchange standards for CAD models
could help produce a digital twin, especially
with the correct data reduction methods to
remove unnecessary data. Automatically
identifying articulation points from a CAD
model can be challenging, but this approach
speeds up building functional models of the
machines being controlled. The more data
that can be reused rather than recreated,
the better.
The most important places to standardize
are protocols for data exchange and device
control, as well as CAD models. The
protocols are needed for the device shell to
communicate with its proxy. CAD models are
needed to produce twins that can provide
visual feedback as well as to interact with a
simulation environment.
What is Digital Twin?
In some sense, digital twin is not a new
concept. Simulation models have been used
for decades. In the past, these models were
only used to develop systems but not
Why may there be confusion? If one looks at
definitions by trade and standards
organizations, what is being called digital
2 https://osgi.org/specification/osgi.core/7.0.0/framework.lifecycle.html
3 https://www.gartner.com/smarterwithgartner/how-digital-twins-simplify-the-iot/
4
https://www.plattform-i40.de/I40/Redaktion/EN/Downloads/Publikation/vws-in-detail-
presentation.pdf?__blob=publicationFile&v=7
- 86 -
November 2019