Railway Signal and Communication DX Frontline: Improving Work Efficiency and Reducing Costs by Utilizing Point Cloud Scanning

Railway signaling equipment and communication infrastructure across Japan are aging, and the aging and shortage of technicians who support them are becoming serious. While the need for equipment renewal and maintenance is growing to maintain safe transportation, the burden on site work only increases due to time constraints on work and staff shortages. For example, inspection and repair work on signals and cables along the track is often carried out during the limited nighttime period from the last train to the first train to avoid affecting train operations, so precise work must be completed in a short time. In addition, the maintenance of extensive railway equipment (signals, level crossing equipment, communication cables, etc.) requires tremendous effort, and relying on traditional manual methods poses a major efficiency challenge.

Against this backdrop, the railway industry is strongly demanding on-site DX (digital transformation) to revolutionize field operations. In particular, recent attention has focused on infrastructure inspection and automation technologies using 3D scanners, AI, and IoT. This article introduces how a new solution that combines point cloud scanning (3D laser scanning), high-precision positioning, and AR (augmented reality) can achieve work efficiency and cost reduction in the railway signal and communication infrastructure field. From on-site challenges to specific use cases, let’s look at the latest DX initiatives.

Challenges faced by railway signal and communication infrastructure sites

First, let’s organize the current challenges at sites involved in the design, construction, and maintenance of railway signal and communication infrastructure (signals and signal poles, level crossing control equipment, along-track communication cables and conduits, etc.).

• Responding to aging equipment and design burden: When planning renewal works for aging signaling equipment or planning new installations, a detailed understanding of the site’s conditions is required. Traditionally, engineers would go to the site to survey, using measurements to determine positions on drawings or with a scale. However, during nighttime work or short windows when train radios are off, there may not be enough time to measure the current situation as desired. It is also difficult at the design stage to accurately grasp positional and height relationships with surrounding structures, and relying only on paper drawings or two-dimensional materials often leaves much to intuition and experience.

• Position layout work during construction and labor shortages: During construction stages where signal poles or communication equipment are installed, the on-site task of accurately marking the drawing positions—“setting out installation positions”—is indispensable. Typically, this pile-driving/setting-out work is performed by surveying specialists in pairs using total stations or carefully using surveying instruments and marking work. However, chronic staff shortages make it difficult to secure experienced surveyors, and carrying heavy surveying equipment lowers work efficiency. On site, crews are racing against time, and the burden of performing accurate setting-out with limited personnel is significant, with safety considerations also required.

• Maintenance and difficulty grasping buried objects: There are also challenges in maintenance after equipment is installed. The exact positions of buried communication conduits (ducts for cables) and wiring routes tend to rely on drawings and records from the time of construction, but over the years these can become outdated and inaccurate, or sites can end up in a state of “not knowing what is buried where.” There is also the risk of damaging existing cables when excavating for new work, so it is important to reliably ascertain the positions of buried objects in advance. Additionally, when equipment conditions are understood based on the knowledge and experience of veteran workers, there is the problem that knowledge transfer becomes difficult with generational change.

• Inefficient information sharing and rework: Poor information sharing of construction plans and site conditions also hampers on-site DX. Even if designers consider the best placement on CAD drawings, it is not easy for on-site workers to visualize it. Conversely, when on-site problems (for example, the presence of an obstacle) are reported to headquarters or the design team, drawings and photos alone may not convey the situation accurately, causing misalignment in understanding among stakeholders. As a result, rework such as “it’s different from the design intent” or “it’s offset from the expected location” can occur after construction, leading to increased man-hours and higher costs.

As described above, railway signal and communication infrastructure sites face multiple challenges such as the burden of precise surveying, constraints due to nighttime work, lack of experienced personnel, and insufficient information sharing. To solve and streamline these issues, digitizing and smartening on-site operations is an effective approach. The key to this is the solution using point cloud scanning × high-precision positioning × AR introduced next.

LRTK solution using point cloud scanning × high-precision positioning × AR

In light of the above issues, LRTK is expected as a trump card for on-site DX. LRTK (pronounced “L-R-T-K”) is a solution that enables “centimeter-class (cm level accuracy (half-inch accuracy)) high-precision positioning,” “3D point cloud scanning,” and “AR display (augmented reality)” with a single smartphone. By combining a dedicated compact high-precision GNSS receiver with an app, surveying and 3D measurement—tasks that previously required specialized equipment—can be performed easily. In other words, it is a revolutionary tool that turns a smartphone into an all-purpose surveying instrument, bringing many benefits to the railway signal and communication infrastructure field.

LRTK’s main features and functions are as follows:

• cm-level high-precision positioning: Ordinary GPS positioning has errors on the order of several meters, but LRTK uses RTK technology (real-time kinematic) to pinpoint the current position with extremely high accuracy—approximately 1-2 cm horizontally and about 3 cm vertically (1-2 cm (0.4-0.8 in) horizontally, about 3 cm (1.2 in) vertically). This allows for accurate acquisition and specification of coordinates for signal pole installation positions and buried cables in a map coordinate system. Positioning is completed with just a smartphone and a pocket-sized receiver, eliminating the need for heavy tripods or large equipment. Because it can be carried and surveyed by a single person, rapid setting-out and measurement tasks can be performed even at sites with staff shortages.

• On-site digitization through 3D point cloud scanning: By utilizing LiDAR sensors (laser distance measurement) and cameras built into smartphones, the site can be recorded directly as three-dimensional point cloud data. For example, by walking the trackside for just a few minutes, you can scan terrain and existing structures (such as bridge piers and sign locations) and obtain high-precision 3D data consisting of millions of points. The acquired point cloud data is georeferenced (latitude, longitude, elevation), so it can be overlaid precisely on drawings and maps. This point cloud scanning effectively creates a digital twin of the site, allowing designers to perform precise measurements and assessments from the office. This can reduce the number of nighttime site surveys and help discover interference points that paper drawings might miss.

• AR display to visualize design data on site: LRTK also includes AR (augmented reality) features that overlay design drawings and 3D models on the real-world view through the smartphone screen. Thanks to high-precision positioning, there is no misalignment in positioning, so models are projected on site at the same coordinates as on the drawings. This makes it easy to, for example, place a virtual pole at a planned signal pole installation point to check sightlines and positional relationships with surrounding objects, or display the route of underground cables from above to check for clashes with obstacles. AR is intuitive and easy to understand, making it useful not only for on-site workers but also for explanations to clients and stakeholders. What used to require building a 3D image in one’s head from drawings can now be shared as a full-scale completed image using AR.

• Cloud integration and data sharing: Point cloud data, coordinate information, and photo records acquired with LRTK can be uploaded to the cloud and shared with stakeholders. Even those without dedicated software can view and measure 3D point clouds via a web browser, enabling real-time sharing of detailed on-site information with office designers and other departments. This makes it dramatically easier to “accurately convey site conditions” and reduces communication loss between design and construction. Also, by storing data in the cloud, past as-built data can be reused for future maintenance planning or other construction, preventing repeat surveys.

Through these functions, LRTK digitizes surveying, measurement, and information sharing across the workflow. The ease of not requiring heavy machinery or specialized surveying instruments is a major advantage in railway construction sites. In the next chapter, we will look at specific scenes where LRTK can be applied in railway signal and communication infrastructure operations.

LRTK use cases in railway signal and communication infrastructure

Considering LRTK’s features, there are many scenarios where it can be applied in the railway signal and communication field. As representative examples, here we present three scenes: “setting out installation positions for signal poles,” “identifying underground communication conduits,” and “information sharing with the field,” and introduce their effects.

Application to setting out installation positions for signal poles

For new signal pole installation work or replacement of aging signals, it is necessary to accurately position poles according to the design drawings. LRTK greatly contributes to the efficiency of setting-out work (pile-driving work).

Traditionally, survey teams would go to the site to measure distances and angles from reference points and mark positions. With LRTK, you can preload the signal pole coordinate data obtained from design drawings to the smartphone via the cloud, and on site the installation position is immediately clear by simply displaying that point in AR. A “virtual pole” or marker appears on the smartphone screen, so workers can intuitively understand where to dig the hole on the actual ground. Also, using LRTK’s coordinate guidance function, the smartphone guides the user to the target coordinate like a navigation device, enabling accurate pile-driving even by non-experts.

Post-installation verification of signal poles is also easy. By overlaying a pole model in AR you can instantly check for misalignment, and if there are no issues you can scan the as-built condition in 3D for records. Reporting to clients or internal teams that the installation was completed “according to design” with 3D data and AR images provides highly persuasive evidence. LRTK implementation not only shortens setting-out time but also brings secondary benefits such as smooth information sharing with stakeholders and simplified deliverable reporting.

Identifying and visualizing underground communication conduits

Communication cables for signal control and inter-station communication are buried along railway lines. LRTK is also powerful for accurately identifying underground communication conduits.

For example, when relocating communication cables in a section, you first need to know the exact position of existing buried conduits. With LRTK, when trial excavations expose underground cable ducts, you can perform 3D point cloud scanning of the surrounding area and record the conduit route in detail. Since the acquired point cloud data includes absolute coordinates, the conduit position can be reproduced accurately later. Even after backfilling, AR display can virtually visualize the conduits from above ground, making it immediately clear that “previously scanned cables are located just beneath here.” This is extremely useful for preventing excavation accidents and for planning future maintenance or other construction.

Furthermore, underground conduit data scanned with LRTK can be shared via the cloud, enabling the design department at headquarters and other construction teams to work with the same information. Routing that was omitted from paper drawings due to update lapses can be stored and shared as accurate, up-to-date digital point cloud data, contributing to organizational knowledge accumulation. As a result, unexpected troubles can be avoided, shortening lead times and reducing costs.

AR-based on-site information sharing and consensus building

LRTK’s AR function and cloud sharing dramatically streamline information sharing between the site and stakeholders. Railway signal and communication works involve many parties—contractors, railway operators (clients), and designers—and it is key that everyone shares the same completed image.

Consider a case of installing a new signal near a level crossing. Whereas explanations were traditionally given using design drawings and perspective images to say “equipment like this will be installed here,” with LRTK’s AR you can show an on-site life-size completed prediction right there. When explaining to clients or local residents, showing the post-completion landscape and equipment placement through the smartphone screen enables intuitive understanding of points that paper materials alone cannot convey. This smooths pre-construction consensus building and helps prevent later disputes such as “it’s different from what we were told.”

Also, as construction progresses on site, performing periodic LRTK as-built checks and sharing that data allows designers and managers located remotely to provide immediate feedback. By reviewing cloud-based point cloud data and photos during meetings, stakeholders can grasp detailed conditions without visiting the site, speeding decision-making. Such real-time information sharing is effective for the tight schedules typical of railway construction, helping prevent rework and ensuring quality control.

Moreover, data acquired with LRTK has value as an asset for the future. By preserving point clouds and positional information as a “digital archive” after construction, it can be referenced for efficient planning during the next maintenance cycle, and new engineers can learn past conditions in 3D. In this way, LRTK functions as a platform that bridges the field and the office, the present and the future with data, contributing to smarter railway infrastructure management.

Conclusion: Take the first step in on-site DX with LRTK

DX (digital transformation) in the railway signal and communication infrastructure realm is an urgent challenge. To efficiently renew and maintain aging equipment and continue safe, reliable work with limited personnel, smartening on-site operations is unavoidable. The LRTK introduced in this article is an easy-to-introduce solution that can serve as the first step to promote such on-site DX.

LRTK, which enables high-precision surveying and 3D scanning with only a smartphone and a small device, is easy to use even without specialized knowledge and can be applied intuitively by anyone on site. Surveying, drawing creation, and verification work that used to take days with conventional methods can be completed on the spot with LRTK, directly contributing to work efficiency and cost reduction. Above all, by using data so that all stakeholders share the same “reality,” waste and mistakes are reduced, leading to improved safety and quality.

Why not start by introducing LRTK in part of your routine construction? Visualize the site with point cloud scanning and make future equipment viewable with AR. The accumulation of such initiatives will steadily advance DX in railway signal and communication infrastructure management. Embrace digital technology to make next-generation railway infrastructure maintenance and construction more efficient and sustainable. The door to on-site DX is already open. As a leading-edge tool, LRTK will support your teams’ activities in the field.