Seeing digital double

The concept of using pairing technology is not new. The National Aeronautics and Space Administration (NASA) used a mirrored system to rescue the troubled Apollo 13 lunar mission in 1970, and now uses digital twins to create, build and test equipment. American professor and manufacturing expert Dr Michael Grieves coined the term digital twin two decades ago.

Engineering consultancy Beca describes a digital twin as “a high-fidelity representation of the real world that looks like, behaves like and is connected to the real world, to improve understanding for decision making”. One of the most widely used digital twins is Google Maps, a simulation of the built and natural environment that can give users real-time updates, for example on traffic and transport.

Opportunities for engineers

Digital twin technology is taking engineering to another level, resulting in better infrastructure outcomes that are more rapidly delivered, says Beca’s Chief Digital Officer Dr Thomas Hyde CMEngNZ.

“It provides a much more effective means of helping people visualise and understand something that’s being proposed. It’s also about breaking down silos – digital twins allow many different stakeholders to work on something simultaneously. It’s a platform you can bring everyone in on, work together, and hopefully make better decisions.”

In addition, he says, digital twins represent a chance to improve productivity in the general construction sector.

“There’s an opportunity to build a lot more automation and standardisation into that process and tackle some broader sustainability challenges.”

To date, Beca has developed digital twins for Fonterra, Bay of Plenty District Health Board and Watercare, as well as global multinationals including pharmaceutical companies. Thomas believes a national digital strategy, including a digital twin of the entire country, is needed “quite urgently” to pull together New Zealand’s fragmented building plans.

The Government’s Covid-19 infrastructure stimulus plans provide the greatest opportunity since the Great Depression in the 1930s to truly improve the built environment, he says.

“A digitally built New Zealand that brings all the digital information together in a national way would better inform decision making.”

It could incorporate all proposed projects and look at, for instance, land-use strategies across forestry, farming, urban intensification and transport. The initiative would tie in with the Government’s aim of stimulating the digital economy and also represent a crucial chance to consider carbon reduction.

Thomas unveiled his proposal at the ReBuilding Nations 2020 infrastructure conference in Auckland last November, where Beca also ran an industry survey.

The highest scored response was to the question: “Is a national digital twin an important thing to have, to support infrastructure?”, whereby 90 percent of survey participants said “yes”.

Around 40 percent thought the Infrastructure Commission would be the best entity to oversee it. Building a national digital twin would not mean starting from scratch.

“There’s a lot happening in the digital space in the various agencies already; it’s about creating a framework that allows everyone to share information and build up a combined picture.

“It will be complex but it’s quite achievable,” Thomas says, adding the country’s engineering industry has “a lot of capability”. New Zealand could also look offshore for resources – such as to the United Kingdom, where the Centre for Digital Built Britain plans to build a British national digital twin over 30 years.

“The technology is there now, it’s more about the will and the organisational framework. But if you leave it too long, the opportunity to inform decisions will be lost.”

Solving backlog

One of Kawerau sawmill Sequal’s mantras is “every millimetre counts”.

As part of its custom-cut service, it aims to eliminate all waste. In 2018, the Tauranga-headquartered company implemented a digital twin that significantly helped reduce loss of raw material.

The product digital twin scans each radiata pine log and generates a 3D model. It then combines that with real-time data from the ordering system to identify the most efficient way to produce its cut-toorder boards.

Sequal also needed to solve an issue with the temporary storage of various-sized boards. There are just 18 bins available, which can result in bottlenecks, says automation engineer Elizabeth Kulasingham.

“Every day is different, so deciding which bins are dropped and stacked is important in order to achieve a continuous flow. If the bins are full we have to stop the entire sawmill and this can lead to substantial financial losses.”

In 2020, Elizabeth, then a fourth-year mechatronics engineering student, decided to create a digital twin that would provide Sequal with a decision-making tool to solve the bottleneck issue.

For their final-year project, supervised by the University of Auckland's Dr Jan Polzer, Elizabeth and research partner Yeeteng Lo developed a simulation model of the production flow.

Their process digital twin interacts with the product digital twin and predicts throughput, based on real-time data related to the individual boards that are arriving on the shop floor.

The new digital twin is already helping Sequal operators in their decision making, says Elizabeth, resulting in a higher production flow. Sequal aims to fully implement the technology later this year, making it an automated process that should have big benefits.

“We hope to decrease downtime and increase productivity. As a result, company revenue could increase by $1 million a year.”

Working smarter

Classical simulation models of production processes have been used by engineers for some time, says Dr Jan Polzer, a senior lecturer in mechanical engineering at the University of Auckland.

Known as digital siblings, these can be handy to identify “what if” scenarios. Even real-time simulations of processes “have been out there for a while now” he says, adding it’s the real-time connectivity and processing of data streams that defines a digital twin. “Feeding real-time measurements, using sensors, into your model is what makes your digital twin an alive, real-time version of your product or process.”

Meanwhile New Zealand cities, including Auckland, Wellington and Christchurch, are exploring ways to make their centres function more efficiently using real-time technology and interconnectivity.

They include everyday uses such as safe swimming advice based on live updates, and rubbish bins that use sensors to alert the council when they’re full, to allow better city planning. Smart cities offer a range of benefits for entire metropolises, says Jan.

“Smart cities make more efficient use of physical infrastructure like roads or public transport and provide sophisticated simulation tools and better opportunities for planning. A digital twin of public transport, with real-time data of bus positions, can dynamically determine the best possible travel route/interchange options, taking into account current traffic jams and delays.”

In terms of manufacturing, using digital twins leads to greater opportunities for improving productivity, Jan says.

“It gives you a deeper insight, leading to better decisions and faster decisions.”

A digital twin enables businesses to do a throughput optimisation in a more systematic way. It also provides a more efficient way to make a root cause analysis. Traditionally, Jan says, quality issues are measured at the end of the production line. Faulty products analysis could take weeks while all the process data was assembled.

“With a digital twin, you press a button and straightaway you get all the process signals. You can start your root cause analysis immediately.”

Embracing Industry 4.0

Originally from Germany, Jan’s background is in automation and throughput optimisation in steel production. Prior to moving to New Zealand in 2018, he led research and development teams working on digital twins in Düsseldorf.

As a project manager he developed and implemented digital twins for factories “to solve realworld problems”. Digital twins are used a lot in Europe, particularly Germany, and in China, he says. By contrast, the uptake in New Zealand has been slow. Meanwhile it is “alarming”, he says, that Gross Domestic Product per capita in New Zealand is 30 percent under the average of the OECD’s top half.

To survive long-term on the global market, it is essential we improve productivity. It is particularly crucial in the era of the Fourth Industrial Revolution or Industry 4.0. This has “transformed traditional shop floors into smart factories and is overcoming the shortcomings of current manufacturing systems”, Jan says.

So, could digital twins be the gamechanger Kiwi companies need? With recent advances in sensing and communication technologies, the Internet of Things has made digital twins more cost effective.

Using the data collected by sensors and building a computer model of a product or process will enable the creation of a digital twin. This gives businesses real-time status updates on products and processes – bottlenecks can be identified, for example.

It also helps with scheduling and predictive maintenance, without putting any assets at risk. One challenge can be a lack of skillset among IT people and engineers.

The University of Auckland’s engineering faculty is aiming to change that, by incorporating Industry 4.0 topics into lectures, and establishing the Laboratory for Industry 4.0 Smart Manufacturing Systems.

Meanwhile, Callaghan Innovation is working with Beca and the Employers’ and Manufacturers’ Association to roll out a mobile showcase of Industry 4.0 nationwide.

Jan acknowledges a big challenge for many Kiwi businesses, certainly small- to medium-sized businesses, is a lack of digitisation. “But all of the companies who have started their digitalisation journey have demonstrated it’s worth the effort.”