An education and training tool that utilizes MR and digital twin technologies to improve engineer skills to ensure expressway safety

Initiated MR tool development toward improvement and standardization of trainees' levels of understanding

Since about 10 years ago, the NEXCO EAST group has projected the aging of expressways and maintenance and management labor shortage and promoted the Smart Maintenance Highway (SMH) project to match the existing expressway maintenance and management technologies that the group has acquired with ICT technologies. Through the project, operational DX has been advanced with proactive application of digital capacities to the field operations, e.g. conversion of paper-based drawing preparation into tablet-based tasks and analysis and utilization of accumulated data with Microsoft PowerBI. Assigned with the project, Mr. Tetsuo Hideshima, the Managing Director and General Planning Manager of Nexco-East Engineering said with regard to the project policies,

"We at Nexco-East Engineering ensure that drivers can safely use expressways by providing inspections and troubleshooting all day, all year. For continuous maintenance and management of expressways, it is critical to conduct thorough inspections and diagnoses without overlooking any tiny changes in facilities and structures. To that end, streamlining and labor saving based on ICTs are imperative."

The company also opened TTC in 2012 as a training facility to enhance performance of expressway inspection engineers. For practical training, TTC offers a training environment equipped with real power receiving and distribution equipment, ETC (automatic toll payment system) equipment, and component samples that are exactly the same as those used on expressways.
With regard to the roles of TTC, Mr. Masayuki Namiki, the General Manager of TTC said,

"At TTC, over 1,000 of our engineers participate in training programs every year. They go through training to enhance skills based on the internal skill check system to become experts of expressway inspection and maintenance, called 'highway doctors.'"

Meanwhile, highway structures and facilities have become more and more complex along with the technological advancement and, despite the hands-on learning with such training materials, levels of understanding of the mechanisms and internal structures varied among trainees. This hindered standardization of trainees' technical levels, constituting an issue for TTC.

The issue was particularly conspicuous in education on ETC equipment. "ETC equipment is composed of multiple devices and how ETC equipment operates was explained with extensive materials such as paper-based radio communication and control signal flow charts, PowerPoint slides, and chalk talks of instructors and then tested with actual ETC devices," said Mr. Yoshitaka Nakamura, the Manager, Facilities Construction Work Division, Facilities Construction Work Department of Nexco-East Engineering.

"However, it requires considerable time to gain understanding of associations among the training materials. Also, radio communication and control signal flows are impossible to see, so we had to rely on trainees' imaginations. This resulted in gaps in understanding."

In response, the company focused attention on the MR (mixed reality) and digital twin technologies. Then a project to develop an "MR for ETC equipment training" was launched out of an idea of combining a 3D model of ETC equipment as well as infrared sensors, radio communication, and data communication routes (which are invisible in reality) with the ETC practice lanes to foster better intuitive understanding.

Endeavor to develop training materials that are easy-to-use for every trainee with no example available as a model

It was DataMesh that contracted with Nexco-East Engineering for its extensive achievements and experiences in the field of digital twins and XR. Mr. Kensho Kashimada, the Director, Marketing and Sales of DataMesh Japan Co., Ltd. looked back, "At that time, there had been no similar attempts at least in Japan. The point was how we could build up MR materials that are easy-to-understand for every trainee while there was no correct answer about what the outcome should be like."

The first step they took to that end was employment the agile development approach based on a quick PDCA cycles, rather than waterfall-model development that relies on detailed specifications from the beginning. "We carefully proceeded with the development through repeated hearing sessions with the project leading department and TTC instructors who would actually use the tool in practice," said Mr. Kashimada.
They also received the same courses that TTC actually provides to trainees to gain knowledge of ETC equipment mechanisms and applied it to the system.

"By receiving lectures with oral explanations and 2D materials, we witnessed how difficult it is to understand the ETC mechanisms firsthand. We could also appreciate the potential value of the tool we were trying to create. So I think it was a very valuable process," said Mr. Kashimada.

Thus, after the development period of about six months, accurate 3D models of ETC devices were made and the MR for ETC equipment training using 3D animation superimposed on ETC equipment that is visible via a tablet device or Microsoft MR device "HoloLens 2" was completed.

"Normally, accuracy of SLAM (Simultaneous Localization and Mapping) in positioning of MR superimposition depends on hardware performance. However, for this MR for ETC equipment training, SLAM features of DataMesh’s proprietary digital twin platform (FactVerse) were used to make SLAM accuracy levels of multiple devices uniform," explained Mr. Kashimada. Ingenuities are made to realize superimposition of massive 3D data without dependence on device performance by using a technology to load necessary portions of data only.
Mr. Kashimada said those features provides trainees immersive experiences in the MR world without stressful events such as misalignment or freezing of 3D animation.

Mr. Namiki said, "It was really a tremendous work to explain invisible things verbally. But now data and radio waves are visible and this increased the level of understanding dramatically."
Once getting used to the operational feeling of HoloLens 2, trainees can adjust the position just by reading a QR code on the display without taking any complex procedure. It was reported that instructors could acquire basic operation methods only though a one-day lecture provided by DataMesh.

The MR for ETC equipment training, which is well recognized by field operators, too, has been further improved based on feedback from instructors. Currently, additional features such as repeated playback of individual work steps and animation speed adjustment for in-depth explanation make the tool even more effective.

MR for tunnel emergency facilities training making full use of HoloLens 2 characteristics

Out of its confidence in the success of MR for ETC equipment training, Nexco-East Engineering promptly commenced next training MR development, which is the "MR for tunnel emergency facilities training."

"The internal structure of automatic water sprinkler system for tunnel emergencies cannot be seen from the outside, so we superimposed a CG simulation of the internal water flow and developed training materials for visualizing internals and operating status," said Mr. Nakamura.

Mr. Namiki said, "In the past, we presented pipe samples from real equipment and illustrations to teach their structures and operations, but we couldn't actually let water through them to demonstrate the mechanism. Also, explanations somewhat varied among instructors. As with ETC equipment, the gap in levels of understanding among trainees was recognized as an issue."

As a measure to resolve the issue, DataMesh reproduced the equipment movements from an onset of vehicle fire to watering and visualized the internal structures based on its know-how acquired through development of the MR for ETC equipment training.
Furthermore, a feature to adjust transparency of 3D animation of water flowing inside the pipe was added give trainees freedom to observe how water flows and stops inside. Implementation of realistic 3D effects of fire also give realistic experiences to enhance understanding.

Finally, quality of this MR for tunnel emergency facilities training is surprisingly high and precise even to experienced engineers including Mr. Hideshima. "From water flow and the valve opening mechanism to things going on behind pipes are all comprehensible at a glance. I sensed the poser of MR anew," said Mr. Hideshima.

As the MR for tunnel emergency facilities training is equipped with the "pseudo reproduction feature" to learn points to check in the event of any malfunction and restoration methods, the MR system has a possibility to be applied to a future remote maintenance system.
Plus, linking tablets and other devices has enabled remote training, creating an environment where a greater number of trainees can take part.

Above all, the MR for tunnel emergency facilities training fully taps HoloLens 2 potential compared with the MR for ETC equipment training.
In fact, for training using the MR for ETC equipment training with outdoor ETC equipment, tablets are mainly used as output devices because visibility of HoloLens 2 can be deteriorated depending on sunlight intensity. On the other hand, tunnel emergency facilities are indoor equipment and not subject to sunlight. This is where HoloLens 2 comes in.

Mr. Namiki said, "While a tablet needs to be held with both hands, HoloLens 2 is a head-mounted display, which sets both hands free. So trainees can touch devices while going through MR training. It also allows individual trainees to rewind, pause, and adjust the transparency level, giving an advantage in tailoring training sessions to individual levels of understanding."

Toward even more effective ICTs through professional collaborations

After realizing the quality training tools by using the digital twin and MR technologies, Nexco-East Engineering has a plan to further promote use of ICTs to address the issues of facilities aging and labor shortage, which are expected to be further accelerated.

Exploring possibilities of ICT usages in various scenes, Mr. Nakamura said, "We have an ambition to expand our use of ICTs beyond TTC hands-on training to online training, OJT training, establishment of hands-on safety education system to improve field safety management skills, and remote maintenance, etc."

With a view to establishment of a system for effective use of ICTs, Mr. Namiki struggling in the field of training said, "In recent years, equipment and facilities have become more and more sophisticated and suffered less failures. It may appear to be a good thing, but on the other side of the coin, most engineers in the future could be inexperienced in failure responses. We would like to establish a system to support engineers with the power of ICTs rather than relying on experienced engineers when the time comes."

On the other hand, Mr. Hideshima is hopeful about professional partnerships. He said, "Although we have excellent expertise in expressway technologies, we admit we cannot fully catch up with ever-improving ICT seeds and technological innovations. In that regard, we are really hopeful about continuation of partnerships with ICT professionals such as DataMesh and Microsoft Japan."

Based on ideal partnerships in which expressway professionals and ICT professionals work together to resolve issues and mutually give valuable input to technologies and knowledge, Nexco-East Engineering will continue maintaining and advancing safety on expressways, one of the essentials of our modern lives.