What You Need to Know About AR Inspection! Key Points to Consider Before Adoption

Table of Contents

• Introduction

• What is AR Inspection?

• Background: Why AR Inspection Is Attracting Attention

• Benefits of AR Inspection

• Main Use Cases of AR Inspection

• Key Points to Consider Before Implementing AR Inspection

• Future and Potential of AR Inspection

• Recommendations for Simplified Surveying with LRTK

• FAQ

Introduction

In recent years, in the construction industry and at infrastructure maintenance sites, "AR inspections" using AR (augmented reality) technology have been drawing significant attention. Surveyors, site supervisors, municipal infrastructure personnel, field staff, and engineers at general contractors — many stakeholders are placing high expectations on this new technology. Behind this are challenges such as severe labor shortages and the aging of experienced technicians, making it urgent to improve work efficiency and promote DX (digital transformation).

In this article, we explain in detail what AR inspection is and the key points to grasp before implementation, focusing on the benefits of AR technology, concrete use cases, and its future prospects. We clearly organize the points readers want to know—what changes will occur on-site when AR inspection is introduced, and what preparations and precautions are necessary in advance. At the end of the article, we also touch on the latest smartphone-based solution, simple surveying using LRTK, and provide information useful for considering the adoption of AR technology.

What is AR inspection?

AR inspection is a method of applying Augmented Reality (augmented reality) technology to inspection operations. When viewing the real scene through a camera or smart glasses, it overlays digital information such as blueprints, 3D models, and measurement data onto that real space, allowing intuitive inspection and verification by visual observation. For example, if you view a structure under construction through a smartphone camera, the screen will display the planned final model and design lines, enabling you to grasp on the spot the discrepancy between the "actual object" and the "design".

In conventional inspections, measurements were taken on-site with a tape measure or surveying instruments while holding the drawings, and then later checked against the drawings. By contrast, a major feature of AR inspections is that they allow checks to be made on-site in real time while comparing against digital information (現場でリアルタイムにデジタル情報と照らし合わせながらチェックできる). Following guides displayed on AR glasses or a smartphone enables less experienced personnel to perform verification tasks with accuracy approaching that of seasoned workers. AR is often confused with VR (virtual reality), but whereas VR operates entirely within a virtual world, AR differs in that it overlays necessary information on top of the real-world view. In other words, AR inspection leverages digital information within the on-site "real" environment to enable more efficient and reliable inspections.

Background for the growing attention to AR inspections

The background to AR inspections attracting this level of attention includes various changes and challenges surrounding worksites. First, in construction and civil engineering sites, a deepening labor shortage and the aging of skilled workers are advancing, requiring high-quality construction and maintenance management to be carried out by a limited number of people. For example, tasks such as surveying and as-built (finished-quality) inspections, which originally would be performed by multiple people over several days, increasingly need to be completed in a shorter time by fewer staff. Also, due to the overtime work regulations applied to the construction industry from 2024 (the so-called "2024 problem"), there is pressure to move away from conventional methods that relied on long overtime hours. Under these labor-environment constraints, AR is expected as a technology that leads to labor savings and productivity improvement.

Furthermore, the promotion of DX at the national and industry-wide levels is also helping. The Ministry of Land, Infrastructure, Transport and Tourism, as part of its "i-Construction" initiative, is promoting the use of ICT and three-dimensional data and has set a goal of improving on-site productivity by 20%. In recent years, the introduction of new technologies such as remote on-site presence (trial of remote site inspections) has advanced, and inspections and checks using AR are attracting attention as part of that. For example, attempts have begun in bridge inspections to use drones and camera footage to perform close-up visual checks from remote locations, and scenarios are envisioned in which deterioration information of structures is confirmed through AR glasses in the future. Construction equipment manufacturers and major general contractors are also independently advancing R&D on AR technology, and it can be said that the cross-industry trend toward AR utilization is accelerating.

Thus, the field's pressing need to 'complete work efficiently and safely with fewer personnel' and the tailwind to 'transform worksites with digital technologies' have come together, increasing interest in AR inspection.

Benefits of AR Inspection

By introducing AR inspection, you can gain various benefits that conventional methods do not offer. Here are the main advantages.

• Because AR allows design data to be overlaid on the actual object for verification, millimeter-level deviations (mm / in) can be detected without being overlooked. Slight surface unevenness or insufficient dimensions that are hard to notice with the naked eye also become immediately obvious when color-coded on the screen. Even without relying on the intuition or experience of skilled workers, anyone can perform high-precision inspections.

• Dramatic improvement in work efficiency: Because you can scan wide areas at once and display multiple checkpoints simultaneously, inspection times are greatly reduced. For example, there are cases where as-built measurement work that used to take half a day was completed in about 30 minutes when using an AR-enabled tablet. Because automatic analysis and pass/fail judgment can be performed in real time, inspection cycles are accelerated, leading to shorter construction schedules.

• Smoother communication and consensus building: AR visuals are intuitive and easy to understand, so explanations to clients and supervisors and information sharing among workers become easier. Simply standing on site and looking at a tablet screen together enables the completed image and problem areas that were hard to convey with paper drawings to be shared by everyone. As a result, rework is prevented and consensus among stakeholders is reached more smoothly, reducing unnecessary rework and misunderstandings.

• Digitization of records and reporting: In AR inspections, the items checked can be saved directly as digital data. Because you can save images that overlay design information on photos and inspection notes tied to locations, report creation is also simplified. Leaving inspection results as a digital audit trail increases their reliability as quality assurance documentation. It also reduces the time spent handwriting on paper drawings and organizing photo logs, easing the burden on personnel.

• Enhanced Safety: Inspections in dangerous high places or confined spaces can be conducted safely when AR technology is combined with remote assistance. For example, if on-site workers share video using helmet-mounted AR devices or smartphones, experienced personnel located remotely can provide guidance by annotating the screen. Workers can perform appropriate inspections simply by following the instructions on their local screen, which in some cases eliminates the need for experienced staff to travel to hazardous sites. In addition, by overlaying no-entry areas and warning markers on live site footage, this approach can also help reduce near-miss incidents during operations.

As described above, AR inspection offers a wide range of benefits, from improvements in quality and productivity to strengthened safety management. By enabling high-level inspections with limited personnel and streamlining recording and communication, it is becoming an indispensable technology for worksites going forward.

Main use cases of AR inspection

The technology of AR inspection is increasingly being applied in a variety of contexts, from construction and civil engineering to equipment maintenance. Here we introduce several representative use cases.

• Quality checks during construction: During intermediate stages of construction work, overlay the design model on site and verify the as-built condition (quality of finish). Because you can check on the spot with AR whether the shape after concrete placement or the finished surface of a developed site matches the design, you can prevent later rework such as "It was different from the drawings!". For example, by displaying the road subgrade elevation as a color map in AR so deviations from the design elevation are obvious at a glance, you can immediately decide to add fill or to cut.

• Rebar placement inspection: AR is also proving useful in inspections that check rebar arrangements in concrete structures. A tablet’s LiDAR sensor, such as on an iPad Pro, can scan the positions of rebar and automatically measure whether the spacing and number match the design. Rebar inspections that used to be done by two people using a tape measure and check sheets can now be completed by one person simply holding up a tablet. On one site, it was reported that introducing this AR system reduced rebar inspection time by 50–70%. It can even measure rebar diameter and concrete cover thickness, and the inspection results are converted directly into electronic reports, achieving both quality assurance and efficiency.

• Visualization of buried assets: Efforts are also underway to visualize the locations of pipes and cables buried underground using visualized with AR. In underground infrastructure work, pipes become buried and invisible after construction, but if their positions are measured in 3D and converted into data beforehand, that information can be checked via AR display after completion. During road repairs, if the routes of sewer and gas pipes are shown on a smartphone screen, locations that must not be excavated become immediately obvious, leading to reduced risk of accidental excavation. In municipal infrastructure inspections, displaying AR on site as well as relying on drawings allows inspectors to intuitively understand "what is buried here" as they proceed.

• Remote presence / remote inspection: AR is also used in methods that allow inspections and on-site attendance to be performed remotely without visiting the site. The on-site personnel stream video using a smartphone or an AR-capable camera, and a remote inspector writes markings and instructions on that video, enabling inspection from a remote location that feels as if you were on site. For example, when conducting a remote mid-term inspection of a highway bridge, if check items are displayed in AR on the on-site video and shared with the remote supervisor, both parties can proceed with the inspection without missing any checks. Since the COVID-19 pandemic, remote presence has attracted attention as a way of working that reduces travel, and AR contributes as a technology that enhances its accuracy and realism.

• Maintenance and Equipment Inspection: AR is also being applied to routine inspections of buildings and plant equipment. Designated inspection items for equipment can be displayed on-site with AR so that workers can check them in order, and digital sticky notes (pins) can be attached to deteriorated areas for recording and sharing. For example, there is a case in a factory where a system was introduced that guides inspectors, through AR glasses, with arrow indicators to the "valve to inspect next." This helped achieve prevention of missed inspections and shorter inspection times. Also, if inspection histories are accumulated in AR space, information such as "the same location was repaired three years ago" can be referenced on the spot, contributing to longer infrastructure lifespan and supporting preventive maintenance.

These are just a few examples, but AR inspection is beginning to produce results across a wide range of areas, from construction quality control to infrastructure maintenance. Devices vary depending on the type of site and purpose—tablets, smartphones, and dedicated AR glasses, among others—but they all share the common feature that AR's strength of "directly linking the site and digital information" is being leveraged.

Key points to address before introducing AR inspection

To successfully implement AR inspection, it's not enough to randomly buy equipment and use it on-site. There are several key points to keep in mind before implementation. Below, we have organized the important matters to consider during the preparation stage.

• Clarify the Purpose of Implementation and Scope of Application: First, be clear about what you are introducing AR inspections for. Is it to streamline quality inspections, for remote assistance, or for safety management? The equipment, apps, and operational workflows required will vary depending on the purpose. Also clearly define the applicable trades and processes where it will be used, and it is advisable to plan to start with a small-scale pilot and gradually expand.

• Required digital data preparation: To overlay information in AR, underlying digital data is indispensable. Ideally you will have 3D design data for buildings and civil engineering structures (BIM/CIM models), but if not, there are methods such as converting 2D drawings into simplified 3D models or scanning the site to obtain point cloud data. Verify the accuracy and coordinate system of the drawings and models you'll be using beforehand, and prepare data that can support AR visualization. If the data is outdated or inaccurate, using AR could lead to incorrect decisions.

• Equipment and App Selection / Environment Preparation: Devices available for AR inspections range from smartphones and tablets to high-performance AR glasses. At first, it is recommended to start with easily obtainable smartphones and tablets. Recent iPhones and iPads are equipped with AR capabilities and LiDAR scanners, allowing sufficient AR use even without dedicated glasses. Also, because GPS does not provide sufficient accuracy for precise outdoor alignment, consider using RTK-GNSS (high-precision positioning) receivers as needed. Check whether the app or system you introduce can integrate with your company's other business systems (for example BIM software or construction management software). In addition, prepare items for field use such as tablet waterproof cases and mobile routers, and don’t forget to arrange the preparation of the operating environment.

• Notifying and Training On-site Staff: When introducing new technology, the understanding and cooperation of the on-site personnel who will actually use it are indispensable. Of course, provide training on how to operate it, and carefully explain "why it is being introduced" and "what effects it will have," proceeding while incorporating on-site opinions. At first you may encounter resistance from veteran employees who are not comfortable with IT, but in many cases demonstrating it will convince them of its usefulness. By establishing operational rules while reflecting on-site feedback, you will achieve smooth adoption and continued use.

• Understanding accuracy and errors: In AR inspections, the accuracy of alignment between the digital and the real world is important. Alignment using a standard smartphone alone can have errors on the order of tens of centimeters (several to tens of inches), but accuracy can be improved by using calibration markers or by using RTK-GNSS for centimeter-level (inch-level) position information. Before deployment, determine the level of accuracy required for your objectives and choose a technical configuration that meets it. "How much deviation can be tolerated?" — if you make this clear, you can perform appropriate adjustments during on-site verification. Conversely, if the accuracy requirements are extremely high, you may need to decide to use traditional surveying instruments in combination rather than relying solely on AR.

• Consider the balance of cost and effectiveness: Estimate in advance the balance between the cost of AR hardware and software and the benefits you will obtain. Equipping everyone with expensive AR glasses like HoloLens can be a major investment, but a smartphone-based approach lets you start at a comparatively low cost. With an increasing number of services available for rental or subscription, you can introduce solutions within a manageable budget. After implementation, quantitatively estimating exactly how much time can be saved and the economic effects from reduced labor costs and fewer quality-related incidents will make your case more persuasive. When explaining to management or securing a budget, presenting these estimated effects will make it easier to gain their understanding.

• Safety and regulatory checks: When conducting AR inspections, attention to safety during work is also required. To avoid risks such as neglecting one’s footing or failing to notice nearby heavy machinery because of focusing on the screen, be sure to provide training that thoroughly enforces checking the surroundings for safety. Also, when utilizing remote on-site presence, investigate the regulatory requirements in advance—such as obtaining consent from the client and supervisors, and complying with guidelines for government/public projects. Although there are currently cases where combined use with conventional methods is required, the government has begun trials, so rules are expected to be developed in the near future. By keeping up with the latest technical standards and official notices and practicing AR inspections in accordance with the rules, you can introduce them smoothly.

Taking the above points into account, if you prepare and plan thoroughly, implementing AR inspections is by no means difficult. There may be some trial and error at first, but if you start small, confirm the benefits, and scale up gradually, it will become established in a form suited to the workplace.

The Future and Potential of AR Inspection

AR inspection is still a new field, but it is expected to evolve further and become more widespread in the future. Let's take a brief look at technology trends and future possibilities.

First, on the hardware side, the improvement in performance and miniaturization of AR glasses and smart glasses is advancing. Currently usage is centered on smartphones and tablets, but in the future AR devices integrated into safety helmets and lightweight, eyeglass-style glasses may become commonplace, allowing AR information to be checked continuously without getting in the way of work. In the late 2020s, companies have begun introducing new models of industrial AR glasses, and the day when workers can more easily perform tasks using "see-through drawings" on site may not be far off.

Also, collaboration with AI (artificial intelligence) holds great potential. If a system can be realized in which AI automatically detects abnormalities and defects from footage captured by a camera and points them out via AR displays, the automation and labor savings of inspections will advance dramatically. AI technologies in the inspection field, such as crack-detection AI and rebar-inspection AI, are already advancing, and by feeding these back to the field through an AR interface, real-time and automated "smart inspection" becomes possible. A future is also envisioned in which humans and AI collaborate to carry out quality control with zero oversights.

Moreover, combined with the cloud and IoT, real-time sharing and storage of inspection data becomes even more convenient. If workflows in which data recorded by AR devices are sent to the cloud on the spot and headquarters and stakeholders can view and approve them in real time become widespread, a speedy inspection and approval process that transcends geographical boundaries will be established. As DX advances, the inspection work itself may transform into a form where "data is collected on site using an app, cloud AI evaluates it, and the results are shared."

Finally, the impact on human resource development and ways of working should not be overlooked. If AR inspection becomes widespread, the parts that have until now relied on skilled workers' intuition and experience can be covered by digital tools even by younger employees. The way skills transfer is handled will also change, and it will become possible to accumulate veterans' knowledge as AR content. Moreover, if inspection work—which used to be physically demanding—is streamlined and the physical and mental burden reduced, it will also contribute to creating a more comfortable working environment. Digital transformation (DX) at the workplace is also one of the measures to address labor shortages, and AR inspection is expected to be an important piece of that.

In this way, AR inspections have a bright future ahead. With technological advancements and improvements in the surrounding environment, the day when "using AR on-site becomes the norm" may not be far off. It may still seem like an advanced initiative now, but in 5 to 10 years the points introduced here could very well be taken for granted.

Recommendation for Simple Surveying with LRTK

One concrete solution for applying AR technology on-site is LRTK (LRTK). LRTK is a combination of a smartphone and high-precision GNSS (RTK method) — a smartphone RTK×AR solution — that enables anyone to easily perform centimeter-level surveying and positioning (half-inch-level).

Traditionally, surveying and as-built verification were tasks carried out using expensive total stations or GPS equipment and handled by experienced surveyors. However, by leveraging LRTK, a palm-sized smartphone becomes a "universal surveying instrument", allowing even less experienced technicians to perform accurate surveys and inspections.

For example, with LRTK, high-precision positioning can be performed in real time using a small GNSS antenna attached to a smartphone and a dedicated app. By combining this with AR display functionality, a single person can visualize positions on the design drawings on site and mark pile-driving locations or scan the terrain and instantly convert the as-built into point cloud data and drawings. In actual field cases there have been many reports of dramatic improvements in productivity and accuracy, such as an operator scanning the ground while walking with an LRTK-compatible iPad completing surveying that used to take 5 hours in about 30 minutes, and examples where staking that previously required multiple people was safely handled by one person. This is the new approach called LRTK "simple surveying", and it is spreading to sites as a surveying method that does not require specialized equipment or skills.

For those who want to introduce AR inspections but don't know where to start, a smartphone-based solution like LRTK is an accessible option to adopt. With simple equipment and intuitive operation, while also achieving high-precision positioning and AR display, it enables 「simple yet professional」 surveying and inspection. By utilizing simplified surveying with LRTK, even sites suffering from a shortage of surveyors can have non-survey technicians take on quality checks and as-built management, accelerating digital transformation (DX) across the organization. If you're interested, why not try it on a small scale at your own sites to experience its effects? By skillfully adopting the latest technologies, you should be able to feel that 「AR inspections will transform the job site!」

FAQ

Q: What exactly is an AR inspection? A: An AR inspection is an inspection method that uses a smartphone, tablet, or dedicated AR glasses to overlay digital information such as drawings or models onto real-world imagery. Because you can compare the actual object and the digital information simultaneously on site, it enables intuitive, high-precision quality checks and surveying confirmations that were traditionally done with drawings and a tape measure. For example, you can verify the dimensions of a concrete structure on the spot against the design model, or inspect the flatness of a finished ground surface by displaying it as a color-coded deviation map.

Q: Do you need expensive, dedicated equipment to implement AR inspections? A: Not necessarily. Expensive dedicated equipment is not always required. Recent smartphones and tablets (e.g., iPhone or iPad) come with advanced AR capabilities, and by leveraging them you can readily start AR inspections. If you need ruggedness or hands-free operation on site, industrial AR glasses or helmet-integrated devices are available, but initial deployment can be done with familiar mobile devices. In some cases external GNSS receivers (RTK-capable) are combined to improve accuracy, and these have also become very compact and affordable in recent years. In short, you can get started with just a smartphone in the current AR inspection environment.

Q: Can AR inspections be used outdoors in strong sunlight or bad weather? A: AR inspections can be used outdoors with some adjustments. However, under strong direct sunlight, smartphone screens and AR glasses displays can become difficult to see, so measures such as using a hood (shading hood) or setting the screen brightness to maximum are effective. In rainy weather, it is necessary to use a waterproof case and take care to prevent water droplets from getting on the lens. Also pay attention to device temperature rise. If used for long periods under direct summer sunlight, the device may become hot and its performance may slow down. While these environmental conditions need to be addressed, you can use AR without problems by making simple adjustments, such as taking measurements temporarily in the shade or working during the cooler times of morning and evening. There are real-world examples of using tablet AR for as-built verification during midsummer road construction, so with basic countermeasures in place, outdoor use is fully feasible.

Q: How should we think about the cost-effectiveness of introducing AR inspections? A: When judging cost-effectiveness, compare the costs of equipment and software with the benefits from improved operational efficiency and quality. On the cost side, if you can repurpose smartphones or tablets, additional investment can be minimal; if you introduce dedicated AR glasses, budget from around a few hundred thousand yen per unit. Software often comes with monthly subscription fees, commonly on the order of several tens of thousands of yen per month. On the benefits side, significant reductions in the time required for inspections and surveys can lead to labor cost savings and shorter project schedules. You can also expect reduced material waste from preventing rework and lower repair costs due to fewer quality issues. For example, if on-site inspections that had been conducted several times a month take half the time after AR introduction, that saves the corresponding labor costs, and if interruptions due to waiting for inspections are reduced, there is an economic effect from shortened schedules. Depending on the scale of the site, if used well, the benefits can easily exceed the introduction cost. We recommend first conducting a pilot implementation to measure the effects and calculate ROI (return on investment) for your company's case.

Q: Can AR inspections be used effectively by both beginners and veterans? A: Yes — with proper training and design, they can be used by everyone from beginners to seasoned professionals. The operation of AR apps is often intuitive, such as using a smartphone camera or tapping to select menu items, and most people who are not familiar with digital devices get used to it after a few uses. In fact, veteran craftsmen are often skeptical at first, but once they try it they frequently say, "It's much easier to understand when you can check the actual object rather than just the drawings!" However, follow-up support is important during the early stages of implementation. It helps to ensure that users can ask questions on site and to provide simple manuals and instructional videos. The key is to customize by incorporating field feedback. For example, if someone says "this display is hard to see," change the screen colors; if there is a request to "simplify this operation," consult the developer — such responses make the system more user-friendly. By doing so, the tool will grow into one that anyone can use effectively on site, regardless of age or experience.

Q: What is LRTK simplified surveying? A: LRTK simplified surveying is a method that, using a solution combining a smartphone and a compact high-precision GNSS device, enables easy high-precision surveying without using specialized surveying equipment. For example, by attaching a dedicated antenna to an iPhone and simply pressing a button in an app, you can record the latitude, longitude, and elevation of a point with centimeter-level accuracy (half-inch accuracy), or obtain point-cloud data of terrain just by walking around. Because the acquired data can be checked in real time with an AR display, staking out survey points and performing as-built checks can be completed on site. What is revolutionary is that tasks that traditionally relied on experienced surveyors can, with LRTK, be performed by anyone in a short time. Though called "simplified surveying," its accuracy rivals professional-grade equipment, and its effectiveness has been proven on many sites. In short, LRTK simplified surveying is a next-generation surveying method that achieves "easy operation with high precision", and it is a powerful tool that can be directly applied to the field of AR inspections.

Q: In the future, will AR inspections completely replace traditional inspections? A: AR inspections strongly complement and improve traditional inspection methods, but for the time being they are expected to be adopted gradually while used in conjunction with conventional methods. Even now, the use of ICT is being promoted in national and municipal construction projects, and AR-based as-built management and remote on-site inspections are being trialed, but a complete transition will require time for rulemaking and for all stakeholders to fully understand and accept it. However, technology advances rapidly, and if its usefulness on site is proven, adoption could accelerate quickly. In the future, inspectors may routinely use tablets or smart glasses, and sites without paper drawings may become the norm. That said, it does not mean human judgment and experience will become unnecessary; AR is, at best, a tool to support them. Ideally, inspections would be carried out efficiently with AR in routine cases, with human visual checks and traditional methods used at key points for double-checking, achieving both safety and efficiency. While future technological developments may replace a significant portion of work with AR-centered processes, it will be important to skillfully integrate them while preserving the strengths of conventional methods.