Speaker: Michael Jenewein
This talk presents a method for on-site adjustment of constructional deviations using
Augmented Reality (AR) and parametric Building Information Modeling (BIM). The construction
of industrial facilities often deviates from the original planning model due to
changes during construction phase. These changes have to be updated to maintain a
consistent as-built BIM as digital twin of a physical facility. Surveying for building reconstruction
is normally done using total stations, laser scanners or photogrammetry. Updating of existing
BIMs is then performed later, in office. Possible errors in this process can be introduced during
data acquisition, data transfer and 3D modeling. To streamline this process, we propose a new
real-time method based on AR. The basic approach is that recognizable geometric differences in
AR view will indicate potential constructional deviations from the original BIM. Required AR
corrections of the planning model to the existing constructional structure are performed using a
wireless connected handheld tablet. Conventional BIM software is not adequate for AR. The
prototype implementation was therefore created using Unity as parametric developer
environment and Vuforia as AR extension. Tracking is enabled through a cuboid multi target
with QR code images. The method is validated through a scale model and an industrial use case
in the environment of a cement loading facility. The on-site AR view showed significant
geometric changes in height and construction of the upper filter. These dimensional discrepancies
could be updated directly in AR. The results show that on-site AR is sensitive to subtle changes
of environmental conditions such as lighting, viewing angles and positioning of targets but the
proposed method also demonstrates that AR adjustment of constructional deviations is possible.