Technologies
The construction industry is continuously getting more digitalised. New software and technologies are introduced, some to greater success than others. These technologies might provide favourable conditions for stigmergy. Other technologies might even have stigmergy as the basis of its development.
Augmented Reality
Augmented reality (AR) combines the real world with computer-generated objects. Virtual objects are aligned to the real objects; thus, it appears as if they belong in the real world. It is mostly experienced through the vision, but other sensory input like auditory might be included (Krevelen, 2007). Augmented reality should not be confused with virtual reality where a simulated environment completely replaces the real one. AR only modifies the perceived environment.
Augmented reality can be experienced through several different devices. Commonly, AR is part of an application on phones or tablets. A very well-known AR example is from the application Pokémon Go. The mobile game became very popular soon after the release. The game uses a video see-through to present virtual objects. The mobile device uses the camera to record a video where it overlays the AR onto the digital image. Video overlay is one of the cheaper ways of presenting AR but has limitations in the field of view. The mobile device has to be moved around manually by the viewer to explore all of the environment (Krevelen, 2007).
Another common way of displaying AR is through head-worn devices. One of the first products on the market was Google glasses, which was designed to resemble eyeglasses. A similar, and now more commonly used, head-worn AR device is Microsoft HoloLens. The HoloLens has briefly been used to project construction models directly on a site. A 3D model might be imported to HoloLens and displayed in real-time and -scale, on-site. AR in construction offers a new way to communicate options of model design. It can display supplementary information about real components seen through the lens. Another use case is clash detection on-site, where the lens detects a mismatch between what is on the physical site and the digital model (Shyu et al., 2018).
HoloLens used to display a structural model with AR
3D Scanning
From 3D scanning of a construction site, a digital 3D model can be made. Regular scans can help in keeping track of the project progress and show the current status of the project. Project tracking allows for monitoring which parts are moving fast and where delays occur. It will also be easier to predict when subsequent tasks can be performed.
A scanned model can be compared to the original design model. From the comparison, deviations and errors in the construction might be discovered earlier and more efficiently (Bosché, 2010). Another aspect is the prevention of mistakes that are about to happen in the construction work. Early detection of problems means they can be handled as they arise. Model comparison is a useful tool in quality assurance by verifying that the construction is built as planned. Discrepancies between the model and the physical reality might act like stigmergic marks. They will stimulate actions of model changes or construction changes on site.
Video showing how a 3D scan can be imported to BIM
A digital model of the physical site might be scanned with 3D laser scanners placed at various location around the site. However, 3D scanning can also be done more easily through handheld mobile devices Spets (2018). A future option might be to equip industrial robots with a scanner. These robots can scan the construction site while surveying it, as illustrated in figure 9, leaving human efforts out of the equation.
Figure 9 The robotic dog Spot developed by Boston Dynamics could potentially be used for 3D scanning.
Robotics
Swarm intelligence and stigmergy have inspired researchers within robotics for some time. The robots have been programmed to move into shapes or perform other tasks. Recently robotics even tried to resemble the building behaviour of insects such as termites, in order to obtain self-organising construction. Some robots can interact with building blocks, avoid obstacles on the ground, and construct in a three-dimensional space. Robots are programmed in such a way that different marks in the environment trigger different actions. The marks indicate where to add or remove components in order to build. The virtual agents are coordinating their construction efforts themselves (Edenhofer et al., 2016). This robotic behaviour, where actions depend on environmental marks, is evidence of stigmergy.
Organising construction in such a way will be different from today’s situation. Should, at one point, this way of constructing be common practice, BIM will no longer be necessary. There will not be any workers to organise or need for scheduling work tasks. Realistically speaking, self-organised construction will not likely be the typical way of constructing for many years to come. First, there might potentially be a transition towards introducing stigmergy in human coordination of construction. Then the next step could be self-organised construction.
Today the robots are mostly prototypes, even though some have been released and introduced on-site (Edenhofer et al., 2016). Development is still in an early phase, and robots are not yet a big part of the construction work on site. However, time will show, maybe some of these robots might become a usual way of constructing in the future. In that case, stigmergy will be a more significant part of the construction industry.