Without a doubt, the digital twin is going to be one of the most important technological trends of 2018. Which is reason enough to explain why the cyber sibling of a production plant, product, component or process is far more than just a simple modelling. Find out what the digital clone can do, and what potential it harbours for engineering and plant operation, here.
Digitalisation, digital data, digital twin – while these terms are often mentioned in the same breath, they need somewhat more differentiated consideration in practice. The relationship between them can be illustrated with the help of an analogy. If someone takes an aerial shot of the centre of Manhattan with a digital camera, the resultant photo may be nice to look at – and the data is certainly available in digital form. Even streets and intersections are clearly visible in the image. But if you try to run your navigation system using this data, all you’ll get from the device is an error message.
Complex data texture
The reason for this is that, while human beings can interpret the mere digital image alone, it doesn’t contain any data that the navigation device can use. For the navigation device to be able to calculate a route and steer passengers reliably, it needs to know where the streets run, how they connect with one another, and where dead ends and one-way streets are situated. By linking together pieces of information, streets that are represented in the photo only by single pixels forming straight lines, become a logical connection between point A and point B. The navigation device calculates a complex model that can also react flexibly to a constant stream of information – for example, regarding the present traffic speeds, current street closures or a wrong turn.
Intelligent facility planning
The digital twin is far more than just a digital carbon copy of its physical counterpart. It draws upon vast amounts of complex data and information that is constantly being supplemented by the industrial internet of things (IIoT). Based on this, the digital twin allows engineering systems to provide intelligent, predictive support for planning facilities. For example, if the information that a pipe has to carry a particular material is stored in the system, it can suggest sealings (e.g. that resist corrosive substances) for further construction or maintenance.
The digital twin as single source of truth
Problems arise when the data are not all sent to a central model of the plant, but to various models. This procedure carries a greater potential for error, since no unified basis can be created for interdisciplinary operations. In this case, instead of working with a twin of the installation, the staff are working with a cousin twice removed owing to the faulty information. The engineering 4.0 required for implementation of Industry 4.0 demands that the digital twin must function as the ‘single source of truth’ for all the disciplines involved. In this way the digital twin is permanently supplied with new information throughout the entire life cycle of its physical counterpart – from initial conception to engineering and maintenance.
Predictive maintenance (PdM) – the traffic report system for plant operation
Whereas the digital photo provides a static image of the status quo, the sat-nav helps drivers to bypass traffic jams in real time. The digital twin, too, helps to avoid standstills, i.e. downtime. In combination with up-to-date data from the real-life plant, it creates a model that enables it to make intelligent predictions about upcoming outages and hence predict when maintenance will be necessary. In this way, cost-intensive repairs and unproductive periods are effectively avoided. This is made possible by recording the plant’s target values in a central database. Thanks to the digital twin, deviations from these values can be identified and plant operators can initiate maintenance measures at an early stage. Navigation devices behave in the same way when they react directly to deviations from the programmed route before – for example – the driver ends up in the Hudson River (‘Where possible, turn round’).
Working across multiple sites
The huge volumes of data must not only be centralised but also managed. To achieve this, a powerful database management system is essential. A multi-tier architecture, with a high level of scalability and multi-user capacity, permits all parties involved to access the same model, the same digital twin, regardless of their location. Particularly where big interdisciplinary teams are at work, and complex process and sequences have to be coordinated, the digital twin is of incalculable value.