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:

Program Manager: Tony Haynes, (734) 995-4930, tonyh@ncms.org