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Opticam Phase III
The Opticam Project addresses Depot needs for
robust reverse engineering technology integrated with manufacturing
applications. The project team has developed a system that uses precision video
cameras to scan objects and produce range data using a parallax scheme. Multiple
views are captured which are then registered automatically by the system to
produce a 3-D image. The 3-D image is then imported into Unigraphics for use by
design and manufacturing engineering applications.
BACKGROUND
The proposed effort plans for the continuation of an existing NCMS Project,
OptiCAM, and Optical Generation of 3D Models for Computer Aided Manufacturing.
The available level of 2005 CTMA funds is not sufficient to allow the team to
meet its initial Phase III goal of completing a “Production-Ready” technology
within a proven, structured, and easily accessible environment.
During its first phase and second year
extension, OptiCAM has surpassed all planned deliverables and is focused on
making an ambitious vision a reality.
Combined with Cross-Service sponsorship,
revolutionary data capture technology and industry leading COTS software, the
OptiCAM team plans to continue work during its next phase.
It is anticipated that after next 4 months of
spiral development under the guidance of NCMS, (National Center for
Manufacturing Sciences) OptiCAM will continue progress toward a collection of
scaleable and commercially available technology.
The OptiCAM process was conceived based on
dramatically cost-laden and iterative processes that currently exist within the
areas of Maintenance, Modernization, and Repair.
PROBLEM
Today, the manufacture of prototypes, first run
parts, or components necessary to sustain the life cycle of a given assembly,
are completely dependent on source data. Various methods of data creation,
collection, distribution, and manipulation all contribute to the integrity of
the data being manufactured or repaired. Accuracy from data collection devices,
data interoperability, and integration to downstream applications like CAM
(Computer Aided Manufacturing) all contributes to target data integrity. The
distribution of that data is dependant on its accessibility.
In a depot environment, the ability to acquire
accurate, up-to-date, 3-dimensional measurements of the equipment is becoming
essential. Models can be constructed based on the measurements that allow design
work and prototyping to be done with less trial and error of physical objects.
Although many practical systems are available
for generating three-dimensional geometry, all suffer from application-specific
drawbacks. An improved and more precise method of 3D model generation holds
tremendous value to the DoD maintenance depots for manufacturing, inspection,
prototyping, and repair.
Majority of current 3D systems require the scan
of an object with a laser beam or contact stylus to generate a cloud of points
from which a model is developed. These systems have several disadvantages
including high cost, large size and weight, and significant modeling time. The
OptiCAM system takes advantage of ongoing development of Spatial Integrated
Systems, Inc.’s (SIS) optical 3D digital video capture device to attack these
issues. The proposed OptiCAM approach directly measures surfaces and is already
producing highly accurate models in a laboratory environment.
PROBLEM
OptiCAM is a collection of COTS (Commercial Off
The Shelf) hardware and software applications tied together with custom
integration. Its core differentiator is based on both revolutionary and
proprietary 3-D Imaging system developed by SIS.
OptiCAM’s objective is to ensure that collected
data will maintain its associative integrity all the way through the
Manufacturing /Engineering /Maintenance process, and interaction and validation
are done in a real-time manner. This objective, thus, requires an infrastructure
that can track data / documents / relationships throughout the life cycle and
provides real-time feedback to the system for maximum flexibility and
efficiency. To achieve this objective we must create a tool, within a sound
architecture, for access to all pertinent data needed for validation at the job
site.
The OptiCAM data capture system is based on
parallax. It is widely understood that parallax (shift in apparent position due
to viewing position) can be used to perform accurate distance calculations.
Parallax is used extensively in photogrammetry and astronomy to determine
distances of objects from a prescribed origin.
In SIS’s device, a sequence of digital images is taken at some spaced intervals
along a line segment or circular arc. Each point in the center image is located
in each of the other images thereby constructing a parallax ray. Using the
center of the camera lens at the center image as the origin, the distance to
every point in the center image can be calculated. Having distance from a fixed
origin allows the calculation of the (x,y,z) coordinates for every point in the
center image.
SIS has taken the existing SIS technology (the
VZX Imaging system) and enhanced the point cloud output. We have also applied
new software programming that allows for almost no user intervention in
combining and aligning a series of point clouds. This enhancement will allow the
users to accomplish several things. First it will allow the use of a rotary
table and as many captures as necessary and the program runs seamlessly (Figure
1). Previously this would require time for the user to analyze the point data
and manually put the clouds into an alignment form that makes sense. A second
advantage of this is that users will now be able to take manual captures of
large objects, such as damage on an area of an aircraft, move the camera and the
system will take care of aligning the point data. Previously and with other
systems as well such as photogammetry, it would be necessary for users to either
go through a manual process or place targets on the objects. The improved
OptiCAM process now eliminates any of those issues.
Unlike other digital data capture systems, no
post processing of the data is necessary to obtain 3D measurements. Users have a
complete, spatially accurate model that is constructed by the system with no
human intervention as soon as the data capture process is completed. Since the
data was generated from digital images, the texture is automatically available.
The Opticam project team is:
- Spatial Integrated Systems, Inc –
technology provider and technical lead
- UGS Corporation
- OC/ALC, PNSY, PSNSY, PHNSY, USCG, NNSY,
CPNAVAIR, Tobyhanna Army Depot – Depots
Program Manager: Tony Haynes,
(734) 995-4930, tonyh@ncms.org
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