CONEXPO-CON/AGG Accelerates Construction DX: Spotlight on LRTK’s High-Precision AR Solution

Table of Contents

• Acceleration of construction DX seen at CONEXPO-CON/AGG

• What is LRTK’s high-precision AR solution?

• Intuitive on-site construction with AR navigation

• Single-person pile-driving guidance

• As-built verification and point cloud overlay with AR

• Sharing site data via the cloud

• How construction DX solves on-site challenges

• Conclusion

• FAQ

Acceleration of construction DX seen at CONEXPO-CON/AGG

In recent years, digital transformation (DX) has rapidly spread across the construction industry, and this trend is now sweeping through construction sites. At the international large-scale construction exhibition CONEXPO-CON/AGG, many advanced technologies that dramatically boost on-site productivity were showcased, drawing significant attention to the acceleration of construction DX. Solutions related to construction DX—such as ICT-equipped construction machinery, drone surveying, autonomous heavy equipment, and 3D as-built management—were all on display. Backed by the Ministry of Land, Infrastructure, Transport and Tourism’s promotion of “i-Construction” and “3D as-built management,” interest in these areas has been growing year by year. At one of the world’s largest construction shows, CONEXPO-CON/AGG, visitors were drawn to numerous digital technologies that contribute to efficiency, labor reduction, and improved safety.

Among these, especially notable was the construction support technology that combines high-precision GNSS positioning with AR (augmented reality). For example, LRTK’s high-precision AR solution—which can deliver centimeter-level positioning, 3D scanning, and AR navigation using just a smartphone—attracted international interest as an innovative approach that directly improves on-site productivity.

What is LRTK’s high-precision AR solution?

LRTK is a solution consisting of a pocket-sized high-precision GNSS device that attaches to a smartphone and a dedicated app. True to its slogan, “Turn your smartphone into an all-purpose centimeter-level surveying instrument!”, simply attach the compact device to your smartphone and launch the app to perform surveying and as-built management tasks that previously required specialized equipment and skilled personnel. The LRTK device supports real-time GNSS positioning augmentation services (RTK) and is compatible in Japan with CLAS signals provided by the Quasi-Zenith Satellite System (Michibiki). As a result, it can provide stable, high-precision positioning with errors of only a few centimeters even in mountainous areas where communications coverage is limited. Errors that were on the order of several meters with a smartphone’s GPS are drastically reduced with LRTK, enabling continuous centimeter-level awareness of the device’s position.

The LRTK app integrates a variety of on-site useful functions that leverage high-precision positioning. The main features are as follows.

• Point surveying: Measure an arbitrary point with one touch and instantly record accurate coordinate values.

• Point cloud scanning: Generate detailed 3D point cloud data simply by walking around while capturing the surroundings with the smartphone’s built-in LiDAR or camera.

• AR display: Overlay lines and shapes from drawings or design models onto the real-world view on the smartphone screen so you can intuitively confirm positions and dimensions on-site.

• Automatic generation of as-built record book (photo log): When a photo is taken, the capture location (latitude, longitude, altitude) and camera orientation are recorded simultaneously, and a photo log is automatically created in the cloud.

These functions greatly reduce tedious manual work and recording errors. In the following sections, we will look concretely at representative LRTK features and the benefits they bring to on-site construction.

Intuitive on-site construction with AR navigation

One of LRTK’s innovative functions is AR navigation for construction support. By displaying the real-world scene on a smartphone screen and overlaying CG of structural positions and reference lines based on design drawings, the system intuitively navigates workers to the prescribed locations. For example, if an underground pipe route is displayed on the floor via AR, you can perceive the positions of buried utilities as if seeing through the ground. You can also display the shape and position of a foundation to be installed as a virtual model on the ground, making it immediately clear “where the structure should be built.”

What deserves special mention is the accuracy and stability of that AR display. With conventional simple AR on a standalone smartphone, the overlay could gradually drift when the user moved. LRTK, however, continuously corrects the device’s position and orientation with centimeter-level GNSS and high-performance inertial sensors, so virtual objects remain firmly fixed in the real world even while walking around. At the exhibition demo, staff moved around holding a smartphone, yet the virtual pipe lines and foundation outlines displayed under the floor did not shift from their real-world positions, prompting visitors to exclaim, “It really doesn’t drift!” and “This could be used on-site right away.”

AR navigation, which can project drawing information directly into real space, is therefore a powerful tool for construction DX. Because workers no longer have to rely on paper drawings or manual layout work, they can follow on-screen guides to grasp correct positions and shapes intuitively—even less experienced staff. This reduces communication loss and construction errors and helps prevent rework. On construction sites, rework often occurs due to misreading drawings or misunderstanding positions, but AR enables accurate visualization from the start, eliminating such waste.

Single-person pile-driving guidance

Traditionally, for foundation work and layout setting (pile-driving), surveying-experienced personnel worked in pairs operating a total station to place piles on-site based on drawing dimensions. LRTK shows the potential to handle this pile-driving guidance with just a smartphone. Using the LRTK app’s “coordinate navigation” function, the smartphone guides the user toward a preset target coordinate with arrows and distance, so the worker can locate the target point simply by following the directions like using a car navigation system.

Specifically, guidance such as “North ○.○ m, East ○.○ m” is shown in real time on the smartphone screen, making the deviation between the current position and the target point immediately apparent. When the distance readout approaches zero and the phone issues a notification, that location is the exact point to drive the pile. In the exhibition demo, staff followed this coordinate navigation and stopped where instructed, and the mark placed there matched perfectly. Visitors applauded and marveled at how “anyone holding a smartphone can do pile layout now,” impressed by its simplicity.

This single-person pile-driving guidance contributes significantly to on-site productivity and labor saving. On sites lacking experienced surveyors or on small-scale projects, LRTK enables high-precision layout without extensive manpower. It also reduces surveying errors because workers no longer need to cross-check dimensions among themselves to establish survey points. This represents a new work style that construction DX brings to the field.

As-built verification and point cloud overlay with AR

In construction, verifying that structures and terrain have been completed according to design—known as as-built management—is important. LRTK streamlines this verification process. Using a smartphone’s LiDAR scanner or camera to walk around and scan the completed object yields on-site 3D point cloud data in just a few minutes. Point clouds obtained with LRTK are aligned to a surveying coordinate system from the start and thus have absolute coordinates, allowing immediate comparison with design data without positional adjustment.

For example, in an embankment project, you can overlay the scanned as-built point cloud and the design model in the LRTK cloud and instantly calculate numerical differences. Information such as whether the embankment is higher or lower than the design elevation and whether the earthwork volume is insufficient or excessive is instantly visualized as a heat map (color-coded map). In the demo at the exhibition, point clouds were uploaded to the cloud on-site and a difference heat map against the design data was generated in a short time. Remarkably, this heat map result was also sent to the smartphone and could be checked with AR display on location. In other words, you can visually see—through your smartphone and right where you stand—whether the spot is “X cm higher” or “Y cm lower” than the design, color-coded for quick interpretation.

This workflow dramatically shortens the time required for as-built verification. Normally, survey teams would measure the site after construction, take the data back to the office, and compare it with drawings in CAD or spreadsheets—a multi-step process. With LRTK, the workflow becomes scan on-site → immediate difference check → on-the-spot correction, reducing instances where as-built errors are pointed out later and cause rework. The combination of point cloud data and AR is a powerful tool to support field adoption of the Ministry of Land, Infrastructure, Transport and Tourism’s “3D as-built management.”

Sharing site data via the cloud

LRTK also offers robust mechanisms for data sharing via cloud integration. Coordinates of measured points, photos, and point cloud data can be uploaded from the smartphone to the dedicated LRTK cloud on the spot. Uploaded data can be immediately viewed and used from office PCs or stakeholders’ devices. There is no need to install specialized software—issuing a shareable web URL allows partner companies or clients without licenses to easily view 3D data, which is a major advantage. For example, if a site supervisor uploads the point cloud obtained from surveying to the cloud, design staff and the main contractor can check the data from the office and immediately discuss whether the construction quality is acceptable or additional embankment is needed.

Furthermore, the LRTK cloud is more than simple shared storage: it includes a viewer that can render point clouds and 3D design models in the browser and measure distances, areas, and volumes. This facilitates office-side detailed analysis and drawing creation based on on-site data. Of course, cloud data is securely managed, with access rights and password-protected sharing links available as needed. Seamless data linkage between site and office streamlines administrative tasks such as report generation and enables real-time sharing of site conditions for timely decision-making.

How construction DX solves on-site challenges

As shown above, LRTK’s high-precision AR solution, which drew attention at CONEXPO-CON/AGG, contributes to solving various on-site challenges. First, regarding issues such as labor shortages and an aging workforce, the fact that the tool can be used by anyone without a specialist operator is a major solution. AR navigation enables even inexperienced workers to identify construction positions without hesitation, and the pile-driving guidance feature allows single-person operation, enabling construction that does not rely on veteran know-how. This makes it easier to maintain consistent quality even on sites with labor shortages.

Second, there are significant effects on shortening schedules and reducing costs. Faster point surveying and point cloud scanning and immediate as-built verification mean that tasks that previously took days can be completed on-site. For example, if earthwork volume calculations can be surveyed and verified the same day, timely revision of construction plans and optimal resource allocation become possible. Early detection of errors and mistakes reduces rework and material waste, leading to cost savings.

Moreover, DX is powerful for safety management and information sharing. Visualizing the locations of buried utilities with AR reduces the risk of accidentally damaging pipes, and immediate cloud sharing of as-built data ensures all stakeholders work with a common set of up-to-date information. These benefits help prevent human errors and facilitate smooth consensus-building. The true value of construction DX lies in reducing waste, unevenness, and inefficiency on sites while improving both quality and safety and increasing productivity.

Conclusion

The movement of construction DX that will shape the industry’s future is gaining momentum at exhibitions both domestic and international. The reason LRTK’s high-precision AR solution attracted attention at international events such as CONEXPO-CON/AGG is that its practicality and innovativeness meet on-site needs. LRTK, capable of surveying, construction support, and as-built management using just a smartphone and a small device, is truly an “all-purpose tool” for the DX era. Going forward, construction sites will require everyone to work efficiently and accurately using digital technologies rather than relying on paper drawings and intuition. LRTK’s demonstrated potential as a solution to support that realization is significant.

By leveraging simplified surveying with LRTK, it is expected that high-precision on-site measurement and recordkeeping that do not depend on experience or specialized knowledge will become commonplace. To avoid falling behind in the wave of construction DX, proactively adopting such cutting-edge technologies is important. As the global construction industry undergoes major changes driven by DX, Japan must also accelerate on-site DX to achieve a productivity revolution. It would not be an overstatement to say that the adoption of advanced technologies will determine future competitiveness.

FAQ

Q. What is LRTK? I heard it was a hot topic at CONEXPO-CON/AGG. A. LRTK is a high-precision positioning and AR solution consisting of a small device that attaches to a smartphone and a dedicated app. It was showcased at international exhibitions such as CONEXPO-CON/AGG in 2026, drawing attention as an innovative tool that enables surveying, 3D scanning, and AR-based construction support on-site.

Q. Can you really achieve centimeter-level positioning with just a smartphone? A. Yes. Using the LRTK device and app makes this possible. By integrating signals from multiple GNSS satellites and using a correction technique called RTK, the system dramatically improves smartphone GPS accuracy. In Japan, it also supports the Michibiki CLAS augmentation signal, allowing stable centimeter-level accuracy even in areas with poor communications.

Q. In what situations is AR-based construction support useful? A. AR construction support is useful for many tasks, including pile-driving, layout marking, confirming buried pipe locations, and checking finished shapes. For example, displaying lines from drawings on the ground via AR enables less experienced workers to install equipment in the correct positions. It is also effective for sharing completion imagery on-site so stakeholders align their expectations before and after construction.

Q. How are acquired point cloud and survey data shared? A. Data obtained with LRTK can be easily shared via the cloud. Uploading from the smartphone to the LRTK cloud allows office staff and other parties to view and use the data over the internet. You can compare point clouds with design models in the dedicated viewer or share a URL so recipients can view the data without special software.

Q. Is introduction and operation difficult? Can people without expertise use it? A. Operation is very simple, and it can be used without specialized training. Attach the LRTK device to your smartphone and launch the app, then follow on-screen instructions to perform surveying and acquire point clouds. The intuitive UI guides the user, so anyone familiar with basic smartphone operation can start using it immediately. There is no need for complex preparations such as setting up a tripod or adjusting instruments, making it easy to adopt for small sites or those who perform surveying as a secondary task.

Q. What are the benefits of promoting construction DX? A. Promoting construction DX offers many benefits, including addressing labor shortages, improving operational efficiency, enhancing quality, and strengthening safety management. By using digital technologies, accurate construction can be achieved in less time with fewer personnel, reducing mistakes and rework. Additionally, direct data linkage between site and office smooths communication, allowing everyone to proceed with the project based on the latest information, ultimately reducing costs and strengthening competitiveness.