The value of Digital Twin technology
Digital twin technology has been trending in the past decade because the use thereof has resulted in technological and business insights across various industries. It is one of the top 10 strategic technological trends identified by Gartner in 20191 and is becoming the focus of innovation leaders in the modern, digital, and connected world.
As an engineer, I have helped businesses create and maintain digital twins of their systems. I’ve been part of a team using digital twin technology to simulate water, ventilation, and electrical reticulation systems for the South African underground gold mining industry. I’ve even worked as part of an Industrial Internet of Things (IIoT) business called “Digital Twin”. Currently, I’m a Senior Software Engineer at CIMSOLUTIONS where I work on simulation software in the aviation industry.
In this post, I will elaborate on this subject matter and show the value thereof through discussing the need for digital twins, what digital twins are and show an example of how a digital twin is used in the aviation industry.
The need for Digital Twins
Before we dive into what digital twins are, let us look at why digital versions of physical assets are needed. Physical assets can be anything from airplanes, airports, ships, trains, manufacturing plants, mining operations and the list goes on. A digital asset is a functional and virtual model of such a physical asset, it’s natural behavior and surroundings.
The value of a digital asset, especially for industrial uses, lies in the understanding of the monitoring and control process (M&C) of a physical asset as illustrated below.
Figure 1: M&C Process
The M&C process requires measurement of performance and environmental data parameters through using automated (real-time) and/or manual data capturing methods. The input data is submitted to a process model where valuable key-performance indicators (KPIs) and control parameters are computed. The KPIs are usually displayed on a dashboard and the control parameters are sent back to the physical asset.
This entire process is also one of the reasons why Internet of Things (IoT) is another rapid growing technology with real business benefits2. IoT enables cost-effective data capturing using edge devices. This provides businesses with valuable data points of their operations. These data points were previously only available to industrial applications with the right sensor infrastructure.
The result of the increased data availability and the operational insights created by them, are better understanding of the physical assets. This enables businesses to create better improvement strategies. However, these improvement solutions still come at a great time and cost to implement, with limited assurance of the actual outcome thereof.
What if you could implement an improvement strategy in an almost exact replica of the operational environment? This is the exact point where digital twins show their potential.
What is a Digital Twin?
A digital twin is a digital representation of a physical asset3. It allows one to utilize a digitalized physical asset in ways that generally has a lower cost than performing such operations on the real system. Examples include, but are not limited to:
- Strategic development of new business opportunities
- Training through simulations
- R&D of improved control strategies
- Incident analyses and earlier fault detection
The use of a digital twin in the M&C Process is achieved through replacing the physical asset with the digital asset as seen below.
Figure 2: Physical [Left] and Digital [Right] assets in the M&C Process
This Figure shows a general setup of a Monitoring & Control (M&C) system connected to a physical and digital asset to the left and the right-side respectively. The physical asset interacts with the M&C system, sampled data (temperatures, pressure, speed, quantities, location, etc.) flows from the asset and is processed. The processed data is then displayed on a user interface (dashboard). This provides an operator with some level of insight into the actual status of the asset. The M&C system also returns control data and actions (valve positions, start/stop, speed adjustments, etc.) back to the physical asset.
A digital asset must be calibrated to represent the physical asset. This means that the digital asset must be able to provide the same input data to the M&C system when supplied with the same control feedback as with the physical asset. It is done in various ways of which the discussion thereof falls outside the scope of this article. Though, this part is very important in the digital twin development process and probably the most time-consuming.
Once you have a calibrated digital model of the physical asset, you can also use the digital asset on the same M&C infrastructure. This means that a proposal for an improvement strategy to the M&C system can be backed up with simulation results, possibly resulting in cost-avoidance or better trade-off analyses between different strategies. Additional advantages can be faster time to market as well as risk mitigation. This also provides another great opportunity, not always possible on an operational system, which is the training of system operators. Here is a hypothetical scenario providing a practical example of the benefits.
Your company provides baggage sorting services at an airport. The airport has indicated that they will be increasing the number of flights handled, which means you need to increase the baggage handling capacity of your system. A team of consultants have proposed either to upgrade the motors driving the conveyor belts or to buy a state-of-the-art software solution, which promises to deliver increased performance.
A digital twin of your environment could allow you to test the performance of both solutions. In the first option you keep the current M&C system (same software) but change the environment (new “digital” motors). In the second option, you adjust the M&C system (new software) and keep the environment (same “digital” motors) the same. For both these solutions you can now run various tests before choosing which solution to purchase.
The tests have shown that the software solution (adjustment to the M&C system) will provide the best performance and you decide to buy the software. Although, you now need to train the system operators to use the new software. Once again you can use your digital twin for this purpose.
This hypothetical scenario is one of many, which highlights the practical use and benefits of utilizing digital twin technology. Next, we look at a non-hypothetical example of how such a system looks and the value it creates in the real world.
A Digital Twin in the aviation industry
The aviation industry was the first to adopt the use of a non-operational system to train people for the real thing. Edwin Link created the first known commercial flight simulator back in 1929 called the Link Trainer4. The flight simulators today have improved to almost an exact replica of what one would experience on a real flight. The safety and reduced cost of operating a simulated aircraft makes it the likely choice for training operational personnel.
This is also true for other parts of the aviation sector such as air traffic control. Air Traffic Control the Netherlands (LVNL) also uses such training simulators. This increases their training capacity for new air traffic controllers and enables development of improved systems for their operational environment.
The picture below shows the view from inside the air traffic control tower at Amsterdam Schiphol airport. This is where air traffic controllers provide ground personnel, the airport, and pilots with the necessary information to safely navigate aircraft in and out of the airport area. The M&C equipment is essential for safe and reliable handling of air traffic, and even more important during low visibility conditions. The M&C systems provide each of the air traffic controllers with the exact information required for them to carry out their tasks.
Figure 3: Inside LVNL Schiphol Air Traffic Control Tower
Figure 2 showed that a digital asset should be able to replace the physical asset in the same M&C environment. This is exactly what LVNL has also done. LVNL created a digital twin of their environment (airport, aircraft, buildings, ground vehicles, etc.) through using simulation software, exact 3D models of their environment and flight data. This digital asset is used in their training environment, while using the same M&C equipment air traffic controllers use in the physical tower.
Figure 4 shows the view from the digital Schiphol air traffic control tower. This is one of the 360-degree simulators, while Figure 5 shows one of the smaller airports’ 180-degree simulators. The key requirement for these simulators is that it should be an almost-exact replica of the operational environment.
Such a simulator enables high quality training programs. It also allows one to develop new features for the operational tower’s M&C equipment and test it in the digital tower first. This shows the versatility of such a digital asset. It allows changing of either the environment (for training purposes) and keeping the M&C equipment the same or changing the M&C equipment (for development and testing purposes) in a similar environment to the physical tower. You can thus test and experience new innovations in a production like environment.
Figure 4: LVNL Schiphol (Amsterdam) 360-degree simulator