Equipment
Haptic Equipment
PHANTOM 3.0 by Sensable
Technologies
Our Phantom haptic simulation devices allow the haptic rendering of
virtual scenes, i.e. you can touch and feel objects that are not really
there. This allows for an unprecedented feeling of immersion in a
virtual reality environment and allows the study of visuo-haptic
coordination, adaptation, and learning in psychophysical experiments.
Our instrument allows us to produce artificial environments with subtle
or gross discordances between visual and haptic information which are
not attainable in the real world.
Description
The haptic setup consists of two PHANToM 3.0 force feedback devices by
SensAble Technologies, Inc. Each device is mounted on a specially made
epoxy block. We aligned the two devices with high precision and reduced
the mismatch between them below 1mm across the central area of our
workspace. The haptic simulation is done on a SGI
Onyx 2 or SGI Onyx workstation and runs at a
rate of 1 kHz. A graphical user interface allows for quick and easy
generation of visuo-haptic scences and design of experiments. The two
PHANToM force feedback devices are used in one workspace in order to
perform easy one-hand precision grips or two handed pointing tasks. The
GUI allows all object properties to be changed on the fly.
Phantom Tutorial and Documentation (UNDER CONSTRUCTION)
Position Sensing Equipment
Hi-Ball Precision Tracker by 3rdTech
The development of the 6 degrees of freedom Hi Ball tracking system
allows subjects to walk in a virtual environment with relative ease.
The HiBall tracker is a recent development based on the Wide-Area
Tracking research project of the Department of Computer Science of the
University of North Carolina at Chapel Hill.
Description
HiBall is an analog/optical tracking system that can track the linear
and angular motion of a receiver at sub-millimeter spatial and
near-millisecond temporal resolution over a large field, making it
ideal for measuring movements of VR HMDs. No other device can provide
comparable speed and accuracy over a wide area. The system triangulates
position using multiple analog sensor/lens pairs to image a number of
IREDs on the ceiling. The device can :
- Provide 2 rooms with 622 sq.ft. and 240 sq.ft of
tracking space
- Maintain extraordinary precision throughout the
tracking space
- Deliver precision unaffected by metal, magnetic
fields, noise
- Built in redundancy overcomes most line-of-sight
obstructions
- Provide very high update rate and low latency -
solid tracking even at high-speed motion
Fastrack by Polhemus
The Fastrack is a 6 degrees of freedom magnetic tracking device. The
device runs at 120hz with 4ms latency. The primary limitations of this
system are its range of 30 inches (without a significant loss in
accuracy and its susceptibility to electromagnetic interference.)
Eye Tracking Equipment
ASL 201 Eye Tracker by Applied Science
Laboratories
The most recent extension to our eye tracking capability is the
inclusion of a separate limbus tracker. Despite it's poor spacial
resolution, the superior temporal resolution of the limbus tracker
allows for updating the display based on saccadic eye movements.
Description
The limbus tracker is mounted on a goggle-like frame with an elastic
strap. Subjects first don the limbus tracker then put on the HMD for
use in virtual environments. The limbus tracker's 1000hz sampling rate
provides 8 millisecond temporal latency. We are currently integrating
it into the experimental control software.
ASL 501 Eye Tracker by Applied Science Laboratories
ASL 501 Online Tutorial
and Documentation
This eyetracker is the centerpiece of our psychophysical
instrumentation. The VR Lab was the first laboratory worldwide to
install eye-trackers into an head-mounted display (HMD) providing the
capability to track the eyes in a virtual environment.
Description
The ASL 501 was recently upgraded to the 5000 series. The tracker,
which is mounted within the optics of our V8 HMD,
runs at 120hz. In addition to the HMD system, we are also able to use
the ASL to track real world tasks. We have developed a system for
recording the image of the observer's eye and overlaying this on the
video record containing the location of gaze. This allows better
evaluation of small eye movements and allows us to minimize the effects
of tracker noise in our data.
ASL 501 Mobile Eye Tracker by
Rochester Institute of Technology
The mobile eyetracker allows exploration of eye movements in real world
tasks and environments. This tracker was built by Rochester Institute
of Technology in collaboration with ASL.
Head Mounted Displays
V8 Helmet by Virtual Research
The V8 Helmet is a stereo display used to visualize our virtual
environments. It contains an ASL 501 eye tracker
and can be used with the limbus tracker at the
same time. Head position is monitored by either the HiBall
or Fastrack devices.
Description
Each of the V8's 1.3 inch LCDs runs at true VGA (640x480) resolution
with 921,600 color elements. The active matrix displays, which are
driven by an external control box, refresh at a rate of 60hz. Field of
view is 60 degrees diagonal. The helmet allows for adjustment of
interpupilary distance. Sound is provided by a pair of Sennheiser
headphones. Each V8 weighs approximately 1kg.
Computing Hardware
Onyx 2 Visualization System by SGI
The Onyx 2 is now the primary system used for running experiments. It
is equipped with 4 MIPS R10000 processors running at 300MHz. Graphics
are rendered by an Infinite Reality 2 graphics engine. Video for the
HMD is output at 60Hz.
Onyx Visualization System by SGI
Other Computers
G3 by Apple
G4 by Apple
O2 by SGI
Athlon by AMD
Pentium 3 by Intel
Pentium 3 Xeon Dual Processor Dell Workstation by Dell
Driving Simulation
Motion Platform by McFadden Systems
The motion platform is a hydraulic system capable of 6 degrees of
freedom. The platform is controlled by a dedicated PC running software
from the manufacturer.
Driving Console by Simulator Systems Int., Inc.
The driving console contains the accelerator, brake and steering inputs
from the driving simulator. Inputs are converted from analog to digital
in an a2d converter before being processed. The console is equipped
with subwoofer-like tactile sensation devices to produce vibrations in
the driver's seat.
3D Digitizing
Vivid 900 by Minolta
This high-resolution 3D scanner from Minolta uses LASER triangulation
to form 3D models of objects. Multiple exposures can be merged together
to form complete 3D representations.
Description
The Vivid 900 uses a 1/3" 340,000 pixel CCD for image capture. Internal
automatically-switched color filters are used to apply textures to 3D
models. Scanning takes 2.5 seconds to capture 307,000 points and an
additional .5 seconds for capturing color information with resolutions
up to 0.039 mm. Software on a Dell Dual P3 Xeon workstation is used to
merge multiple exposures for more complete 3D models. 3D models can be
output to VRML files.
Video Equipment
Hi-8 VCR by Sony
Hi-8 VCRs have been the workhorses for video recording in the lab.
Mini-DV VCR by JVC
The addition of a DV VCR has brought the lab up to a new level of
high-resolution digital video recording. The new format offers the
digital benefits of lossless dubbing along with an IEEE 1394 Firewire
port. Firewire allows easy video transfers to our PCs and G3/G4 systems
for simple editing and distribution.
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