Future infrastructure lifecycle management systems have several
requirements, such as integrating lifecycle data and providing access
to databases, supporting 4D visualization and interaction, representing
virtual spaces and different scales of space and time, adapting
construction related standards, and providing support for
spatio-temporal analysis. Using these systems in mobile situations will
allow on-site infrastructure field workers, such as construction
superintendents and bridge inspectors, to use mobile and wearable
computers to interact with geo-referenced spatial models of the
infrastructure and to automatically retrieve the necessary information
in real time based on their location, orientation, and specific task
context using Virtual Reality (VR) or Augmented Reality (AR)
techniques. AR allows interaction with 3D virtual objects and other
types of information (e.g. text) superimposed over 3D real objects in
real time. The augmentation can be realized by looking at the real
world through a see-through head-mounted display equipped with sensors
that accurately track head movements to register the virtual objects
with the real objects in real time. In these systems, field workers
will be able to access and update information related to their tasks in
the field with minimum efforts spent on the interaction with the
system, which results in increasing their efficiency and potentially
their safety. VR and AR environments can be considered as two cases of
the concept of Mixed Reality (MR) introduced by Milgram et al. (1994)
where different combinations of the virtual and real components are
possible along a virtuality continuum. In order to realize the virtual
components, information about the objects’ shapes and locations is
organized in a database using a geospatial model so that augmenting of
the 3D real scene with data extracted from the database is possible. 3D
models of urban and infrastructure environments can be used as VR
models or added as augmentation to the real environment in order to
analyze different scenarios, such as urban planning, emergency response
simulation, or virtual reconstruction of sites. Virtual Environment
Real Environment Mixed Reality Augmented Reality (AR) Augmented
Virtuality (AV).This paper discusses several issues related to
interaction models for infrastructure management systems using virtual
and augmented realities. The paper focuses on new VR and AR interaction
models that have been developed especially to suit the requirements of
mobile infrastructure management systems. These models will be
discussed within a larger framework called Location-Based Computing for
Infrastructure field tasks (LBC-Infra). LBC-Infra facilitates
collecting inspection data by allowing field workers to interact with
geo-referenced infrastructure models and automatically retrieve the
necessary information in real time based on their location and
orientation, and the task context (Hammad et al., 1999; Hammad et al.,
2004).