Many of our readers are familiar with the general concept of virtual commissioning, and have an understanding of its applications across industries. However, in the pursuit of understanding virtual commissioning in all of its facets, a brief primer in history is worth reading – a history that started more than 20 years ago.
Understand Virtual Commissioning: The Beginning
Since its inception, the intention of virtual commissioning (VC) has been to help solve a variety of problems that can arise when manufacturing systems are brought together for integration and operation with a programmable logic controller (PLC). The automation industry has long acknowledged the potential benefits of using virtual models to simulate the performance of physical systems, where integration issues could be spotted before entering into the expensive process of physical integration. For a successful VC, however, the virtual plant model must be an accurate representation of the system in question, and while these kinds of models had some prominence in the aerospace and automotive industry, their implementation was lacking in the automation market. To achieve implementation, companies needed plant models that could be integrated with their PLC design methods – something unavailable by the early standards of plant modeling.
As early as 1999, researchers were hard at work trying to define and propose VC strategies (Auinger et al. 1999) that could realize these expected benefits. A technique called “soft-commissioning” was described that could pair simulation tools with hardware PLCs, and help debug a portion of the expected behavior of the physical system. Although the technology was still severely lacking, the researchers were able to demonstrate success. Since that time, VC development has been organized into four categories of general control development (Auinger et al. 1999).
The Four Categories of Control Development
Understanding virtual commissioning in today’s market would leave you without the historical framework for VC-based control development. The four general categories of control development were initially outlined to differentiate how different parts of the system were made virtual.
- Traditional Commissioning involves testing the physical system (plant) against the hardware controllers without the assistance of virtual modeling techniques.
- Soft Commissioning (or Hardware-in-the-Loop (HIL) testing), employs a virtual plant model that is used to test the hardware controllers.
- Reality-in-the-Loop, alternatively, tests simulated hardware controllers against a constructed, physical system.
- Virtual Commissioning is the process of testing that uses both a virtual plant model and a virtual control system for simulation.
Each of these four strategies requires different technologies in order to be successful. By 2010, researchers were still working on improved ways to facilitate a user-friendly approach to the VC process (Hoffmann et al. 2010). They described the major challenges as 1) the easy creation of sufficient plant models, and 2) the ability for these plant models to work in tandem with PLC development software. In light of these challenges, practical implementation of VC techniques was deemed out of reach by the standards of 2010.
2010-Present: Virtual Commissioning Takes Off
Despite these challenges, technologies have now been developed that make VC implementation possible for the majority of automation companies. As far back as 2006, it was demonstrated that VC techniques stood to save up to 75% of the time required for traditional commissioning when studying German machine tool builders (Zah et al. 2005). Today, new technologies and software integrations are significantly reducing the historical barriers associated with virtual commissioning.
It’s easy to believe that virtual commissioning is a brand new technology, and perhaps it seems as if VC has only really hit mainstream understanding in the last couple years. By understanding virtual commissioning and a bit of the history associated with the technology, it’s clear that people have been eyeing VC for almost 2 decades. The practical applications only started to gain real traction in the last decade, but you can see how the growth curve of VC technology looks more exponential than anything. In just the last few years, we’ve seen even small companies adopt the technology to great results.
Stay tuned for the coming weeks where we dive into the details of a few other details of virtual commissioning fundamentals, including system-level modeling in general, and how these models came to be categorized under the umbrella of digital twins.