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Laser
Scanning, Rangefinding and Flash Profiling
Acuity
Technologies has 2 types of active (projected light) shape capture
technology. One is based on scanning laser rangefinding (LADAR),
the other on projective geometry and structured light photogrammetry.
Our scanners work at ranges up to 600 meters. The stuctured light
projection systems have ranges up to 10 meters and can capture several
million 3D points in a single laser flash.


SRI-500
Scanning Rangefinding Imager

      Acuity's SRI-500 imaging laser rangefinder
uses a unique single-mirror scanning system to obtain scans up to
360 degrees by 130 degrees in less than a second. Sample rates are
up to 800,000 points per second with range to 150 meters, or 200,000
samples per second to 600 meters. Short range systems have an accuracy
of 50 mm, while the longer range systems are accurate to 100 mm.
Additional
product information.

      Above, a 360 degree scan of a simulated
crime scene was scanned with an Acuity AR4000 and scanner. Below,
the points obtained are reduced to a triangular mesh. The data is
then overlaid with a color photo taken from the same viewpoint as
the depth map scan. Below right, a new virtual viewpoint has been
generated and rendered from the combined depth map and image data.
Photos courtesy of 3rdTech.
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Polygon
Mesh from Scan |
Mesh with Color Image Data |
A
Synthetic Perspective |
Laser
Flash 3D Imaging - Structured Light Photogrammetry
      By projecting a pattern of light on an
object and imaging it from multiple directions, many points on the
object can be identified and resolved in 3-space. This approach
can be used to resolve over 1 million 3D points on objects ranging
in size from a few millimeters to 10 meters across from a single
photograph with exposure times down to 1 microsecond. This enables
real-time 3D capture of complex transient and vibratory deflections
and motion. The high accuracy of conventional photogrammetry can
be attained without targets, at unprecedented point densities. A
white paper describing an aircraft suface mapping application can
be found here.
Snapshot
Surface Mapping

      Acuity has developed a capture system for
field and industrial capture of surface contours and discontinuous
shapes. The system has accuracy of 0.01 inch or better at over 1
million points distributed over a region 100 inches across from
two or more images obtained with a high resolution handheld digital
camera. A tripod or permanently mounted projector projects a pattern
onto the surface from which the point positions can be derived.
This can be moved to allow capture of different overlapping areas
which can be combined into a single surface representation. The
working envelope of the system is from less than 10 inches to beyond
500 inches, with accuracy proportional to the distance from the
camera to the surface.

Gasifier
Furnace Profilometry
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      Acuity Technologoes is prototyping
a profiler for gasification furnaces under a Dept. of
Energy contract won by Process
Metrix, a developer of equipment for the steel and
chemical industries. Process Metrix has contracted with
Acuity to develop components of a system capable of
obtaining fast profiles of furnaces at operating temperatures.
These profiles are necessary to monitor ablation of
the furnace wall during use without cooling the furnace,
which can take several days. This application requires
fast capture in an extreme environment though a small
aperture. |
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Other
Applications
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      Acuity’s equipment is used
by Sierra Pacific Industries to create 3D maps of logs for
cut optimization. Large mills process up to 30 logs per minute,
and accurate scanning is required to maximize the use of raw
material without slowing throughput. A sample log map created
with the AR4000 and 4000 Scanner is shown at right. |
1998: Acuity develops a rangefinder for JPL for their work
in the DARPA Tactical Mobile Robotics Program, shown at right
with the JPL scanning mirror system. |
In 1994 CMU’s Field Robotics Lab selected Acuity’s
AR3000 for the primary ranging imaging vision system for path
planning on Dante II, a hexapod walking robot. The AR3000
is visible at the top of Dante, pictured at left in a crater
on Mt. Spurr, Alaska. |
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