ECE 497
Capstone Design
Purpose of the System
• The purpose is to create a scanning system to
determine the location and size of metal
fragments in a medium density fiber panel.
Background Information
• As part of its many scientific efforts, the Weapons Integration and
Development Directorate (WDI) of the US Army Aviation and Missile
Research, Development, and Engineering Center (AMRDEC) performs a
variety of explosive and warhead research and development activities.
When testing explosive charges, a typical method of recording
fragmentation parameters uses stacks of fiber panels (bundles) placed
around the charge. Upon detonation, fragments embed themselves in the
bundles at various depths and orientation. The bundles are then
disassembled layer by layer. Each layer is then searched by hand for
fragments with a rare earth magnet. The X/Y position of the fragment is
then measured and recorded, and the fragment is removed from the
bundle, identified, bagged, and tagged. The fragments are later cleaned
and weighed. The sheet from which the fragment was removed is used as
a measurement of depth of penetration. The key measurement criteria
are: position, depth, and mass of the fragment. The process takes many
hours of repetitive labor that could potentially be automated.
Project Description
• The Army is looking for a device or method for quickly producing
the required output data. The top surface of the sheet will not be
completely smooth, as fragments and spalling will interrupt the flat
surface. The fragments may be highly irregular (non-spherical), and
they may or may not be securely embedded. Some may be loose
and can fall out easily. There may be as many as 96 sheets in a
bundle, and at any one time only 3 can be lifted together. Data
derived from the analysis of the fragments should be in a
spreadsheet format, with the fragment designation, count, sheet
number, location, and size/weight. Fragments are typically steel,
but some tests use titanium or aluminum. It would be beneficial to
be able to locate and identify these metals as well. The desired
threshold parameters are described below.
Parameters
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-X/Y resolution of .5”
-Minimum fragment weight of .25g
-Maximum time per person per sheet
of 15min.
The scanner can be developed as a purely hardware solution or
hardware/software solution. Fragment testing is performed in remote
areas in the firing range for personnel safety. So, mobility is required
for the scanning system. The system must be hosted on a portable
device (tablet, laptop, etc.). Windows and Android operating systems
are allowable for software development. No Apple operating systems
or products are allowed. No Bluetooth connectivity is allowed. WiFi
can be used, but fragmentation tests are normally performed in areas
of weak reception, or areas with blackout restrictions on
transmissions. USB thumb drives are not permitted per US Army
security regulations. Data can be migrated between the system and
any US Army data networks for additional analysis. Acceptable data
migration techniques are: optical storage (CD, DVD, etc.), SATA, eSATA, or Firewire. USB external drives can be used to backup data
only.
Scanning Systems
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Ground Penetrating Radar (GPR)
Industrial Radiography
Ultrasonics
XRay
Ground Penetrating Radar
GPR Scans
What is Ground Penetrating Radar?
• GPR is a non-destructive imaging method that uses
radar pulses to image the subsurface.
• The radar pulses used are in the microwave band of
the radio specutrum.
How does GPR work?
• GPR works very similar to a metal detector. The GPR
system sends out thousands of frequencies in to the
ground. The frequencies that return to the antennae
correlate to differing material compositions in the
subsurface.
Industrial Radiography
Describing Industrial Radiography
• Industrial Radiography is also a non-destructive
detection method which utilizes X-rays and gamma
rays to view materials
How Industrial Radiography Works
• Similar to medical radiography, Industrial radiography
uses an X-ray source to bombard a sample with highenergy radiation onto a film or a digital detector. This
creates a 2D image of the different materials in the
sample.