Intro to AR for Civil Engineering: Augmented Reality Technologies Supporting Construction DX

Table of Contents

• Introduction

• What is AR?

• The Role of AR in Construction DX

• Benefits of Implementing AR

• Use Cases of AR in Civil Engineering

• Challenges of AR Adoption

• Conclusion: Accelerating Construction DX with Smartphone Surveying (LRTK)

• FAQ

Introduction

In Japan's civil engineering and construction industry, digital transformation (DX) to improve productivity has become urgent due to labor shortages caused by population aging and a decline in birthrate, as well as issues such as the "3Ks" of on-site work (kitsui—tough, kitanai—dirty, kiken—dangerous). Starting with the Ministry of Land, Infrastructure, Transport and Tourism's proposal of "i-Construction" in 2016, the adoption of ICT to streamline operations and the use of 3D data have been promoted, and from fiscal 2023 the principle application of BIM/CIM (3D models) in national-government-led projects began, accelerating the digitalization of construction sites dramatically.

Among the trends in construction DX, one technology that has attracted particular attention in recent years is AR (Augmented Reality). AR, which overlays digital information such as drawings and 3D models onto live camera views from smartphones or tablets, has the potential to significantly change construction management and surveying methods that previously relied on craftsmen’s intuition and experience. However, many people may wonder, "I've heard the name, but what is AR? What can it do on civil engineering sites?" This article explains in an easy-to-understand way for beginners the basic mechanisms of AR and how it differs from VR, AR's role in construction DX, concrete benefits and use cases, and the challenges and points to consider when implementing it. Please read to the end as an introductory guide to imagining the world of AR in civil engineering even if you're new to it.

What is AR?

AR (short for Augmented Reality) is a technology that overlays digital information onto real-world scenes. Using cameras and sensors to recognize the surrounding situation, virtual objects such as text, shapes, and 3D CG are placed so they appear to overlap with the real environment. While VR (Virtual Reality) immerses users entirely in a virtual world, AR is characterized by adding information to images of the real world.

Familiar examples include smartphone games that make characters appear in real streets, or camera apps that let you place virtual furniture in a room to try it out. More recently, using filters on social media to apply effects to faces has become common, and AR is beginning to penetrate widely from entertainment to business.

In construction, AR is mainly implemented by overlaying site footage and 3D data through the cameras of smartphones and tablets. Using dedicated AR glasses (transparent smart glasses) allows workers to view AR displays while keeping both hands free behind goggles. However, because device costs are high at present, many sites mainly use smartphone- and tablet-based AR apps that are easy to use.

There are broadly two methods to realize AR. One is vision-based (image-recognition) AR, which aligns based on the device’s camera images. Specifically, there is marker-based AR, where pre-installed markers (QR codes or drawings, etc.) are read by the camera to display information, and markerless AR, which recognizes landscapes or objects themselves by feature points and overlays content. The other is location-based AR, which displays information according to the current position obtained from positioning systems such as GPS or GNSS. For outdoor construction sites that require alignment over wide areas, location-based AR using satellite positioning data is suitable.

The Role of AR in Construction DX

ICT utilization across the entire construction process—from surveying to design, construction, and maintenance—is indispensable when discussing construction DX. The Ministry of Land, Infrastructure, Transport and Tourism’s "i-Construction" initiative set goals such as 3D surveying using drone aerial photography and 3D laser scanners, consistent use of 3D models through BIM/CIM, and improved efficiency of as-built management by measuring completed shapes with point cloud data, aiming to increase site productivity by 20% by fiscal 2025. In fact, from fiscal 2023 the use of 3D models (BIM/CIM) became a principle in nearly all national-government-led projects, rapidly advancing the digitalization and sophistication of data in the civil engineering industry.

AR is a key technology positioned as an extension of this trend. Even when 3D design models and survey data are created, until now they could only be checked on paper drawings or on screens, limiting their onsite use. By using AR to bring digital data directly into the real site and visualize it, the gap between the office and the field can be bridged. For example, showing a three-dimensional image of the finished product onsite—something difficult to convey with drawings alone—lets owners and contractors share the same image for discussion. As a result, mistakes in reading drawings and miscommunication of design intent that cause rework can be prevented, and consensus formation is accelerated.

Moreover, AR is expected as an intuitive way to utilize point cloud data and CIM models obtained through ICT construction directly at the site. Intuitive features that relied on veteran intuition can be visualized based on data with AR, making it easier for younger staff to accurately understand and judge site conditions. AR, which provides digital technology in a form that anyone on site can use, can be said to be the final piece of construction DX that will support the civil engineering industry going forward.

Benefits of Implementing AR

Introducing AR technology to construction sites offers various benefits that traditional methods do not provide. The main advantages are summarized below.

• Productivity improvements through labor savings and efficiency gains By using AR, tasks that previously depended on manual work or experience can be digitized, automated, and sped up. For example, layout work that relied on reading drawings can be simplified by displaying virtual markers at installation points in AR, making positioning obvious at a glance and reducing surveying and layout effort. Early detection of mistakes reduces rework and shortens schedules, leading to overall cost reduction effects.

• Smooth information sharing and consensus building Visualizing expected completion or construction processes onsite with AR enables all stakeholders—owners, designers, and contractors—to share the same image. Things that were hard to convey by words or drawings alone can be intuitively understood by showing life-size 3D models onsite, reducing communication loss. Consequently, discussions on design changes and inspections of workmanship become smoother, preventing unnecessary rework or conflicts.

• Improved quality control and safety If you can overlay design models with the built object using AR, you can immediately detect and correct finishing errors or deficiencies on the spot. This reduces human error and prevents quality defects and rework. Also, visualizing the locations of buried objects and restricted areas in AR allows workers to easily recognize points that require caution, contributing to safety measures.

• Contribution to skills transfer and securing human resources Tasks that required the instincts and know-how of skilled workers become easier for less experienced staff when visualized in AR. Sharing veteran knowledge as digital information can break away from person-dependent work and standardize procedures. In addition, adopting advanced technologies attracts younger talent, which helps address labor shortages and contributes positively to work-style reform.

Use Cases of AR in Civil Engineering

So how can AR actually be utilized at civil engineering and construction sites? Here are some representative use cases.

• Quality checks by overlaying as-built and design models By overlaying as-built structures or terrain with design models in AR onsite, deviations in the finished shape can be identified immediately. For example, after concrete placement, 3D scanning the structure and overlaying that point cloud data with the design’s 3D model on a tablet can visualize differences in height and dimensions as a color-coded heat map. Because discrepancies are emphasized on the actual object through AR, it becomes obvious at a glance what needs to be corrected, greatly improving the efficiency and accuracy of quality inspections.

• AR visualization of construction progress (schedule management) Visualizing the progress and upcoming work in AR can help with site management. Project milestones’ "expected completed forms" can be projected onsite as 3D models and compared with current conditions to intuitively grasp deviations from the plan. For example, in excavation work, overlaying the excavated cross-section with the design excavation line in AR makes it obvious whether the required depth and shape have been reached. You can confirm onsite whether work is proceeding as scheduled or if there are delays or errors, improving the precision of construction management.

• Visualization of buried objects and work navigation Displaying the positions of pipes and cables buried underground on the ground surface in AR reduces the risk of accidentally damaging them during excavation. By showing pre-acquired 3D data or drawing information of buried objects in AR onsite, the "invisible" becomes visible, enabling safe and accurate work. During construction, workers can also be guided by displaying AR markers or arrows on the ground indicating the position and elevation of the next structure to be installed. This reduces the need to measure while holding drawings and allows layout tasks such as pile driving and pipe installation to be performed efficiently by a single person.

• Presentations to owners and local residents AR is also effective as a presentation tool to convey the finished image to stakeholders. For example, in new road or bridge construction, showing the post-completion appearance via AR onsite to owners and local residents in advance allows sharing of the expected outcome. What was previously explained with CG perspectives or models becomes an AR image overlaid on the real scenery, increasing persuasiveness and helping obtain residents’ understanding. In meetings with owners, considering options using AR overlaid on real views instead of drawings reduces image gaps and leads to smoother consensus building.

• Remote support and training AR technology is also attracting attention as a tool to support sites remotely. By streaming footage shot by a worker’s smartphone or AR glasses over the internet, and having office-based technicians write AR instructions or markers onto that footage, precise remote support becomes possible. Even without skilled personnel onsite, remote experts can guide in real time through AR, helping alleviate labor shortages and supporting training. There are cases where trainees learn by following procedure guides displayed in AR, using it for training purposes.

Challenges of AR Adoption

Despite many benefits, there are several challenges to overcome when introducing AR onsite. Here are the main points to note.

• Positional accuracy and technical challenges To accurately overlay information in AR, high positional accuracy and stable tracking technology are required. The GPS accuracy of a smartphone alone has errors on the order of 5–10 m (16.4–32.8 ft), which is insufficient for precise civil engineering alignment as-is. Also, GPS reception may be unavailable indoors or near high-rise buildings. Nowadays, using GNSS augmentation signals and RTK technology, centimeter-class positioning on smartphones (half-inch accuracy) is becoming possible, and combining such high-precision technologies is key to AR utilization.

• Cost and equipment challenges Equipping dedicated AR glasses and high-performance surveying instruments can require significant investment. However, in recent years solutions have emerged that realize AR with commercially available smartphones or tablets and inexpensive peripheral devices, making introduction relatively low-cost. To use AR onsite, it is necessary to prepare devices with sufficient performance and communication environments, but with the spread of mobile devices this hurdle has been lowering.

• Data preparation and security challenges Preparing and properly managing 3D models and drawing data to be displayed in AR is also important. If a BIM/CIM environment is not in place, you need to start by converting design data into 3D. Moreover, when sharing drawings and models via the cloud, security measures such as information leakage prevention and permission management are required. Data volumes tend to be large, so attention should be paid to communication capacity and device storage.

• Operational and human resource challenges To make new technology take root onsite, training for site staff and establishment of operational workflows are essential. Initially, older engineers may show resistance, but gradually introducing the technology through user training and demonstrations that show tangible benefits is important. Depending on site conditions, AR should not be relied on exclusively and may need to be used in combination with conventional methods. By continuously improving while incorporating feedback from the field after introduction, AR can be established and its effects realized.

Conclusion: Accelerating Construction DX with Smartphone Surveying (LRTK)

With the advancement of DX, AR will become an indispensable technology at civil engineering sites. Especially the recently emerged field called smartphone surveying is making AR use even more accessible. By using a high-precision GNSS receiver for smartphones called "LRTK," a palm-sized smartphone can quickly transform into both a surveying instrument and an AR device. The LRTK series conforms to the Ministry of Land, Infrastructure, Transport and Tourism’s ICT construction requirements, and is already being used at many sites as a solution that allows "anyone with a smartphone to perform surveying and AR display with centimeter-level accuracy (half-inch accuracy)."

By attaching LRTK to a smartphone, you can utilize high-precision positioning information delivered from Japan’s Quasi-Zenith Satellite System and others, making centimeter-class positioning—previously requiring surveying instruments costing several million yen—easily achievable. This greatly reduces the labor involved in alignment work that was a challenge onsite, and allows point cloud data and CIM models to be displayed and used in AR at the correct positions immediately. Smartphone surveying that combines high-precision positioning and the cloud brings the era where anyone can practice cutting-edge AR construction management within reach.

By quickly adopting such latest technologies onsite, your construction sites can evolve to the next stage. If you are interested in introducing AR technology to your sites, please also check details about the smartphone RTK device "LRTK." Harness the latest digital technologies and realize productivity improvements through construction DX.

FAQ

Q: What is the difference between AR and VR? A: AR (Augmented Reality) overlays virtual information onto the real environment. VR (Virtual Reality), on the other hand, immerses the user completely in a virtual space and does not display the real scenery. Simply put, AR provides an experience of "the real world + digital information," while VR is an experience of a "world of digital information only."

Q: What are the benefits of using AR in construction? A: There are many benefits such as improved construction efficiency, reduced mistakes, and better communication among stakeholders. AR makes it possible to intuitively share site conditions, reducing rework caused by misreading drawings and leading to improvements in quality and safety. Also, tasks that relied on veteran intuition can be done by anyone based on data, contributing to training younger staff and addressing labor shortages.

Q: What is needed to use AR at construction sites? A: Basically three elements are required: device, data, and an app. Specifically, a terminal such as a smartphone or tablet for AR display, digital data such as drawings and 3D models, and a dedicated application (software) to perform AR display are needed. If the smartphone or tablet is compatible, additional devices are not always necessary, but if higher positioning accuracy is required, combining with RTK-capable GNSS receivers and other equipment may be used. For outdoor use, also check radio and communication conditions.

Q: Can AR be used without specialized knowledge? A: Yes. AR apps are designed to be intuitively operable by site workers. Some training and practice are needed, but those accustomed to smartphone camera use or games should be able to handle them relatively smoothly. You may feel unsure at first, but once you learn how to use them, even older personnel can utilize them effectively. Onsite, it’s important to prepare easy-to-understand manuals and support systems so the whole team can gradually get accustomed.

Q: Is high-precision surveying and AR display possible with only a smartphone? A: Yes, it is possible. In recent years, small GNSS receivers (RTK-capable) that attach to smartphones have appeared, enabling centimeter-level positioning with a smartphone. For example, using devices like LRTK, you can perform high-precision surveying with a single smartphone and then display AR with accurate positioning. Also, the latest smartphones come with LiDAR scanners in some models, allowing on-site 3D scanning to obtain point cloud data and immediately overlay it in AR. Advanced surveying and AR that once required dedicated equipment are becoming achievable with just a smartphone.