Virtual meets reality

When you rush through the construction of a new machine without thorough testing, you risk letting fundamental flaws in the design go unnoticed until commissioning. At that point, any changes to the finished machine are extremely costly and time consuming. That's why a growing number of machine builders are using simulated models – digital twins – to test and implement new machine designs quickly and cost effectively.

When designing a new machine, one of an OEM's primary concerns is getting it built and on the market as quickly as possible. Delays, complications and failed prototypes can quickly threaten a project's economic viability. Conventional approaches to machine development and deployment are no longer up to the task. That's where digital twins come into play.

A digital twin accompanies a machine throughout its entire lifecycle – from conceptual planning to after sales service. Parallel to the real machine, it is developed, adapted, improved and tested. Any design flaws or necessary changes are brought to light through simulation before going to the expense of building a physical prototype.

In addition to simulating the machine's hardware and software, the digital twin must also provide a realistic real-time representation of production processes. Simulating the movement of products on a conveyor belt, for example, helps identify potential collisions early on. "A simulation tool needs to visualize high-speed processes in conjunction with the real controller," notes Isabella Laasch, product manager for simulation and digital twin technology at B&R. "So, in addition to being very powerful, it must also offer real-time capability."

These are two criteria that industrialPhysics satisfies perfectly. With an integrated real-time physics engine, the software simulates dynamic machine behavior in 3D. All the dynamic forces that impact the flow of materials can be tested using the digital twin. The machine developer gets instant visual feedback about how behavior is affected by different combinations of machine components. Unnecessary downtime can also be quickly identified and eliminated.

industrialPhysics generates digital twins using the machine's CAD data. The developer simply imports this data in STEP format, and can then quickly and easily create a digital twin. The digital twin can then be used to test how different kinematic arrangements, component configurations and code changes will affect the machine.

B&R has integrated industrialPhysics into its Automation Studio engineering environment. "The direct link between the simulation tool and Automation Studio means that developers are able to run the virtual model of the machine right on the PC – in a hardware-in-the-loop or software-in-the-loop configuration – and connect with the controller," says Laasch.

In order for developers to interact directly with the simulated machine without outside distractions, the model needs to be available in three dimensions. industrialPhysics offers the option of viewing the digital twin in a virtual reality or augmented reality headset. Developers can experience the planned machine in three-dimensional space – and with simulated movements even in four dimensions. "With a VR headset, the developer can evaluate production processes with the simulation running. It's also possible to connect to a real controller or test handling," says Laasch.

Unlike a VR headset, an AR headset superimposes the digital twin over the machine's real environment. This makes it possible to test what-if scenarios when planning and developing machines with moving objects. Information can be obtained from the controller in real time and viewed along with the simulation. The VR and AR systems can easily be integrated in the software in a matter of minutes. industrialPhysics simulation models are then displayed directly in the VR or AR headset rather than on the PC screen.

After a machine's hardware and software have been developed and the production processes have been tested, it is time for virtual commissioning. Thanks to the digital twin, the commissioning process can be repeated over and over until everything is working optimally. Only when things go perfectly smoothly in virtual commissioning is the first physical prototype built. "Virtual commissioning is extremely inexpensive compared to the real thing. So you use the digital twin to eliminate as many errors as possible and run through as many prototype iterations as necessary before building and commissioning the real machine," explains Laasch. That has a positive impact on the return on investment.

The benefits of a digital twin don't end with commissioning, however. The connected factories of the Industrial IoT generate and process enormous volumes of operating data. A digital twin can put this data to good use. "Supplied with the machine's real-time data, the digital twin runs like a virtual copy of the machine in the control cabinet," explains Laasch. If the behavior of the real machine deviates from that of the digital twin – because of a worn out bearing, for example – the difference is detected immediately. The collected data can be used for predictive maintenance, fault reporting or remote maintenance systems.

A digital twin also helps when it comes time to upgrade or expand the machine. Insight gained during operation can be fed back into the development process. The machine builder is able to use the simulation model to test the planned modifications. This minimizes the amount of time the machine needs to be down to implement the changes.