Advancements in simulations render it more and more unnecessary to build physical
prototypes of new development. Nevertheless, after extensive simulation, a point
is reached where the simulation results have to be verified using physical
prototypes. Comparing the experimental results with those of a simulation can be
tricky, though. Augmented Reality techniques can help here by overlaying the
real experimental data like a smoke trail in a wind channel with the
visualisation of simulation results like trace lines, creating a “hybrid”
prototype. This enables an expert to directly compare the experiment with the
simulation. As those experts are normally scattered around the globe within
distributed teams and virtual organisations, means have to be found to consult
them without introducing a large overhead like travelling costs and time. This
setup will be used in IRMOS as a scenario. At one side, a development team with
virtual and hybrid prototypes wants to discuss the outcome of a simulation and
the experiments on a car within a wind tunnel with a remote expert.
The local team itself is distributed, as the wind tunnel is situated in another
hall, a few hundreds of meters from the virtual environment the local team is
using. The wind tunnel contains a car body; the experiment will involve the
production of stream lines with a smoke probe. Some of the engineers, using a
head mounted display device, will do a local analysis of the experiment,
overlaying it with the visualisation of the simulated data. The image, together
with a set of other images captured by fixed cameras arranged around the
physical prototype, will be transferred to a local CAVE and to the remote
expert, situated in another location. Also, the simulation results will be
distributed to all partners. The expert can select from multiple perspectives,
including the perspectives of the local engineers, or automatically receive an
image of the position closest to his actual position, thus enabling him to
virtually walk around the car and perform his analysis. An audio-/video
conference is used in the discussion by all partners. The connection will be
routed via the IRMOS network. An initial bandwidth is reserved that allows the
smooth transmission of all simulation data, video and audio streams.
The simulation data itself will be generated by a continuously running simulation
that is directly connected to the visualisation. The current setup of the wind
channel like angle of attack and air speed will be fed into the boundary
conditions of the simulation, thus the same parameters for both will be used
while the experiment is running. This enables a virtual test bed over a wide
area network, making it possible to verify a full series of experiments. As
post-processing of the simulation data can be quite complex and resource
intensive, resources have to be found that are able to cope with this task.
Thus, IRMOS platform will be used to locate the required resources, deploy a
COVISE installation there and connect it to the existing COVISE session, running
the CPU-intensive modules on the new nodes.
Interactions with the shared prototypes can be manifold. The engineers in the
wind tunnel can move around the car, changing their and the remote team’s
perspective on the real experimental data. Those new views are transmitted into
the connected virtual environments and desktop workspaces, displaying the
current view and the current position of the observer. All partners can
influence the visualisation of the simulation results. They can collaboratively
change the virtual streamlines, add isosurfaces, place markers and annotations
to the data set in question, take snapshots for later reviews, etc. Of course,
also physical and virtual parameters affecting the running simulation can be
manipulated. Adding a real-time distribution of data, streams and feedback would
give distributed teams a perfect workspace for carrying out collaborative
sessions as if they were sitting together in the same room performing the same
task, without the usual lag and noticeable inconsistencies in transmission. This
has the potential to render unnecessary many physical meetings, enabling faster
and higher quality development cycle using distributed teams.
The scenario will show how data needing a consistent data rate and low latency
can be improved using the IRMOS infrastructure, running at top of a real, wide
area network link. As mentioned earlier, the quality of every visualisation
session is highly dependent on the speed and also reliability as when new data
is available. IRMOS flow control and path monitoring tools will be exploited for
ensuring a smooth and reliable frame rate.
- Intensive real time processing for performing the simulations – usage of
distributed nodes, parallel processing – for guaranteeing the perfect
synchronisation of the experiment with the simulation.
- Integration of real time multimedia applications and collaborative tools – some
application to share the results of a simulation/experiment and also for the
communication of the different actors.
- Real time integration of real and virtual images. Allocation of requested nodes
for CPU-intensive processing for the integration of real images and simulation
results into the virtual environment, which requires a tight synchronisation of
the pictures streamed into the virtual environment.