Exploring Augmented Reality for Construction

Infrastructure is inherently 3-dimensional. Designers propose a 3D building concept, and ultimately builders create the 3D object that corresponds to the designer’s idea. Yet, the only design document that is legally approved for construction is the 2D drawing. Of course, 2D drawings are essential documents for construction, as they represent an efficient way of looking at and understanding the complex 3D model information. But the process forces designers, architects and engineers to take one dimension out of their 3D design.  Therefore, drafting consists of a complex set of tasks aimed at accurately representing 3D objects with 2D representations. The process is complex and must be done with great care, to ensure that when the builders read the 2D drawings, they will be in a position to build the 3D building exactly as it was designed.

Plans must be followed carefully. Unfortunately, construction workers cannot work with drawings in their hands – as they need their hands to do the construction work. They cannot constantly look at the drawings either. So drawings are often put on a table on the site, and workers frequently come to look at it, understand it, and to take measurements. In the process, errors may be made. A builder may take the wrong measurement. Or he may be looking at the wrong drawing. Or even just not looking at the drawing at all, basing his work on what he remembers from what he saw previously on the drawing. This happened when our family house was built: the builder had put the fireplace at the wrong depth with respect to the surface of the wall. When I showed him that the drawing clearly indicated it should be off the wall by 6 inches, he said: “You're right!... I had not seen it I guess...”  We really need to find better ways to look at drawings. Actually, we need to find better ways to look at the information conveyed by drawings.

Drawings contain lots of information about a building – one problem is that workers do not have the drawing constantly before their eyes. The fact that they sometimes have to manually measure distances on the drawings, make calculations, and hold figures in memory, may lead to error. They should carry the drawing with them, all the time. Even better: the drawing should be displayed on a tablet, which would display only the parts of the drawing that are appropriate for a given task (for instance: it would display just one of the 4 sections that appear on a given sheet, the one that matters to the worker at that specific time). But the drawing, on its own, is not the solution. A drawing is a representation of what should be built in the physical world - however that representation is very abstract... To fully understand it, one could lower the level of abstraction by displaying the drawing within a context.  Although drawings are 2D, they actually each represent a specific location in the 3D building. For instance, a section drawing represents a section of the wall at a specific (authored) location. Then why not display it right there? I mean display the drawing in the physical building, at the exact location it represents? Displaying the drawing in combination with the physical world may provide the context required to help understand the drawing better. Such a combined display could be achieved using Augmented Reality.

Our team has done quite some work in the Augmented Reality (AR) field. AR displays digital data in the context of the physical world. This helps interpreting the digital data (as it is then displayed in a context). It also helps interpreting the physical world, as it then comes with supplementary data. With augmented reality, the whole really is greater than the sum of its parts.  We have already explored the possibility of displaying 2D drawings in the context of the physical world, as represented by pre-recorded panoramic images (see our blog post), in a static augmentation experience.  We wanted to go one step further and let the augmentation be more dynamic.

In this project, we wanted to see what it would be like to build a building using a live AR system. How could we render (or present) the digital data in such a way that would be useful for the worker? Would the builder really benefit from it? What issues would need to be solved, to be in a position to make such a system operational?

So we developed a basic AR system for construction, that consists of:

  • a set of 3D video eyewear equipped with video cameras, 
  • an orientation sensor (for measuring the head orientation),
  • a set of 3D game controllers (for measuring the head position).

Our results are shown in the video below.