Applications of augmented reality during construction stage

Abstract

With the rapid development of virtual reality (VR) technologies during past two decades, building information modeling (BIM) tools have been improved quickly and applied extensively in architecture, engineering and construction (AEC) industries. In the basis of BIM, technologies of four-dimension (4D), five-dimension (5D) or incorporation of all possible dimensions have been developed in recent years. These technologies have been utilized for architecture design, construction planning, facility management, and building demolishment. Project managers could share and exchange virtual data of BIM, 4D or 5D, send feedback to each other, and improve the original data. According to the literature review, in the respect of real-time share and exchange of virtual data, the practical construction phase has not fully benefited from VR technologies. Namely, a break of continuous utilization of digital data in the building life cycle has been existed. This problem may be caused by the complexity and dynamics of the construction site. Even though the construction planning could be tested and improved by related software tools before practical building, the implemented scenarios have been probably different on site. In other words, virtual data created by BIM and multidimensional tools have not released the full potentials during construction stage. This research attempts to fill this gap with an emerging technology called augmented reality (AR). AR can display virtual data in physical real-word environment in real time. ARToolKit software library was used for creating AR applications. In order to achieve high-performance rendering effect of virtual data, a rendering engine of 3D scene graph was introduced, which is called OpenSceneGraph (OSG). An integrated library framework of ARToolKit and OSG termed OSGART was also used, in which more flexible and free AR technologies can be supported. In this research, augmented reality-aided construction system (ARAC) was built with ARToolKit, OSG and OSGART. By using computer with a camera, ARAC was implemented with virtual data of SHUI CHUEN O project in Shatin Area, Hong Kong. The study found that, ARAC users on site could intuitively checked the digital data of geometry, spatial relationship, quantities and properties of building components. The virtual operation guides shown in real environment would assist users in finishing tasks more quickly and accurately. Users also could refer the virtual construction simulation and other dynamical operation. Moreover, actual finished building components could be compared with designed virtual 3D models in real time. If there were differences between finished components and designed BIM models, it could be identified directly by AR technology. Users on site could feedback these differences to the designers and planners, then get updated construction scheme which improved by BIM or multidimensional software tools. This feedback loop could improve the construction process, enhance operation efficiency, and update original virtual data which could be utilized after construction stage. In terms of continuous utilization and improvement of virtual data, ARAC bridged the break between construction implementation phase and other phases in the building life cycle.