Courtesy, Bentley Systems   

A virtual "hole" showing underground utility lines is overlaid onto a photograph of a city street in an example of augmented reality.

Imagine a world where you can “see” the real world around you as it is, but with an added “virtual” overlay. For example, view a restaurant through the lens of your smartphone and its menu and latest reviews appear; or aim your phone at a storefront and instantly download a coupon.

And it’s not just for consumers.

Now imagine you have a work order to replace a light fixture on the side of the highway. Aim your phone at the poles in a general area and the one you need to repair is highlighted. Aim your phone at a circuit board and information such as which circuits have been replaced, when and by whom instantly appears.

This is “augmented reality” technology, an extension of virtual reality modeling (VRM). Augmented reality has actually been around for awhile, particularly for marketing purposes, but other applications are on the horizon.

A recent report released by construction industry group Fiatech, in conjunction with the United Kingdom-based organization COMIT (Construction Opportunities in Mobile IT), explores the promise of using augmented reality to enhance interpretations of modeling data.

The publication “Advancing Asset Knowledge through the Use of Augmented Reality Technologies” covers the first two phases of a three-phase study. Phase I dealt with an actual highway construction project in the U.K., where the contractor was installing live-streaming cameras for security and construction overview purposes.

Phase II centered around the Bond Street Underground Railway Station project in London, an underground location that simulates conditions in which fixed, live-stream cameras would prove ineffective and other real-time location systems such as GPS would be impossible. The third phase of the project is now in design.

The objective is to demonstrate the potential applications of augmented reality, how it can enhance processes, business value and the exchange of information. 

Augmented reality is intended to help people more efficiently interpret digital information. This technology, coupled with the use of 3D models and handheld devices, can help construction site operators, engineers and maintenance technicians to better understand advanced modeling data and work in a more intuitive way than they might with written instructions or electronic manuals.

Other Fiatech and COMIT members involved in the project include Bechtel, Bentley Systems, Bosch, Costain, Crossrail, Korec and Network Rail.

“Engineers use tons of digital information in various forms. To access information, you might have to browse through a stack of (specifications) sheets or several databases,” said Stéphane Côté of Bentley Systems, who has provided technical expertise on phases of the project. “With augmented reality technology, the world around you becomes the database.”

Take an object in the physical world like a manhole, for example. Augmented reality allows you to “touch” the manhole by filming it with your smartphone or tablet camera, and the system would then automatically display information about that manhole.

Côté said that some of this remains science fiction for the time being. Aligning physical data to virtual data requires extremely accurate positioning, which is very difficult to achieve.

“In order for this to work, you must be able to identify the exact position and orientation of the iPhone or tablet being used,” said Côté. “If you have this position within 3½ millimeters, augmented reality is much easier to implement.”

Though augmented reality is not readily accessible in the engineering world, the technology is being developed for smartphones and tablets and has found several applications in various fields for which accurate positioning is not a big issue.

An app created by acrossair for the iPhone points Londoners to the closest subway station based on their phone’s video function. Users load the app and all 13 lines of the London Underground are displayed by different “floating” colored arrows. By tilting the phone skyward, people can see the nearest stations and the direction they would take to get there, among other data.

“In a construction setting, let’s say an architect has to visit a building site every day to make sure the work is within specs and is not late,” said Côté. “He has specs on 2D drawings and has to compare these to the 3D building to make sure everything is accurate to specifications. With augmented reality, the 3D model could be displayed overlaid with the building being built, making it very easy to compare without having to make physical measurements.”

Sounds great, right? So, what is the hold-up?

“At the moment, the main hurdle is accuracy,” said Côté. “Let’s say there are 160 lightposts along a highway and you need to fix No. 24. If you aim at the road to see which one to fix and your position is not accurate, you might fix the wrong one. There will have to be a way to visually indicate the level of accuracy to the user so that he can make the right decision.”

Obtaining the level of accuracy required for augmentation in the engineering world is difficult, as such applications require positioning of the phone or tablet being used to within millimeter accuracy.

“Researchers are looking now at how to use the camera image to help pinpoint the camera’s position with higher accuracy,” said Côté. “We are making progress and getting close, to within a few centimeters, but we’re not there yet.”