In perfect harmony

"The whole is greater than the sum of its parts." – What Aristotle knew in ancient Greece is truer than ever in the age of smart factories and Industry 4.0. After all, a machine is much more than just a pile of hardware and software components. Only when the parts work together in perfect harmony can the whole reach its true potential. Achieving and maintaining that harmony is where simulation can make all the difference.

What role does simulation play in building plants and machinery? "The answer is simple," says B&R's product manager for simulation, Isabella Laasch. "It's a key that unlocks efficiency at every phase in a machine's lifecycle."

As machines grow increasingly complex, the interplay between their mechanical, electrical and automation components becomes increasingly difficult to orchestrate. Throughout development and commissioning and during operation, the behavior of the machine needs to be tested and adapted. Doing that on a real physical system can be costly, time consuming or, in many cases, simply impossible.

Even during the first phase of its lifecycle – development – the machine goes through multiple stages. Serious defects can creep in at any point along the way. The "Rule of Ten" states that the cost of correcting these defects increases by a factor of 10 for each stage of development they pass undetected. In other words: the sooner you are able to correct defects, the faster and cheaper it becomes to develop the machine.

Any flaws that don't get caught during development will become evident when it comes time to commission the prototype. "If you get all the way to commissioning and problems start popping up one after another, that's a nightmare," says Laasch. "Not only have you already gone to the expense of building a prototype, you now have to devote valuable development resources to troubleshooting." If the hardware is damaged, there will also be additional expenses and potential delays waiting for replacement parts. In the worst case, contractual penalties may even be incurred if the new machine can't be delivered on time.

"So what we need is a way to work with a digital model of the machine at every phase in its lifecycle," says Laasch. "And the way to do that is through simulation." When you replicate every aspect of the machine in a virtual simulation environment, you create a digital twin. With the help of the digital twin, it becomes easy to see during development how different components will interact later on – or even validate the behavior of the entire machine with virtual commissioning.

Machine builders have a wide variety of simulation tools to choose from. Some specialize in modeling machine hardware, while others simulate physical processes. B&R has integrated a full selection of tools into its automation system through many years of cooperation with companies that specialize in simulation.

"Thanks to partners like MathWorks, Maplesoft, machineering and ISG, we're able to offer an array of simulation options and have the right solution for each application," explains Laasch. "The main thing here is that our customers are free to choose the simulation tool that best suits their machine. And whatever they choose, they know it will work seamlessly with the central B&R development environment."

The simulation software from Maplesoft and MathWorks, for example, makes it easy to create detailed models of machine components and simulate torque and other forces needed for design and sizing. It's easy to simulate all types of different load conditions and perform testing that, on a physical system, would take many hours and tie up extensive resources. With physical testing, there's also the risk of overloading and damaging valuable hardware. In the simulation, on the other hand, you can see at a glance whether or not the machine can handle a given load.

When it comes to simulation of processes, that's where the tools from machineering and ISG come into play. They show the dynamic behavior of an entire machine in 3D. All the dynamic factors that influence the flow of material can be tested in real time using the digital twin. The machine builder gets instant visual feedback about how the behavior of the system is affected by different combinations of machine components. It also becomes possible to detect issues early that could otherwise result in downtime.

Even after the machine has been developed and deployed, the digital twin is not done adding value. In the control cabinet it continues to run as a virtual copy of the machine, using real-time operating data to make accurate forecasts about the health and remaining service life of the machine's components. "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," Laasch explains. The collected data is used for predictive maintenance, fault documentation, remote maintenance systems and more.

Having a digital replica of the machine also opens up new possibilities for training machine operators and service technicians. The ability to work with the HMI or the machine itself before it actually arrives on site dramatically shortens their learning curve.

Another increasingly popular use for digital twins is in digital showrooms, where OEMs can present new machines to potential customers at any time, even outside of events and trade fairs. With the help of augmented reality headsets, the audience can experience the digital machine in a realistic environment. All types of "what-if" scenarios can be explored during planning and development – delivering all the insight with none of the risk.

"The digital twin accompanies a machine for its entire life," says Laasch. "But it also spans machine generations – by serving as the basis for future upgrades and improvements." A machine builder can apply insight gained during operation to optimize the system, using the simulation model to safely test any planned modifications. This minimizes downtime when implementing upgrades and accelerates development of the next machine generation.

Forfatter: Carola Schwankner, Corporate Communications Editor, B&R