1. Infrared Seeker Calibration Mechanism
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Infrared Seeker Calibration Mechanism
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2. Raytheon Seekers Aaron Scrignar……Team Leader Eric Draves………..Historian
Trevor Moody…….Web Page Des., Mediator
Stacy Davison……..Document Coord., Financial Officer
LaTanya Williams…Communicator
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3. Presentation Outline Client Description Problem Definition
What is Infrared Imaging?
Project Requirements
Design Method
Prototype Design
Analysis Process
Project Spending
Time Log
Conclusion
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4. More about…
Raytheon
One of the largest defense electronics contractors in the world. Leader in defense electronics, including:
Missiles; Radar, Sensors and Electro-Optics
Intelligence, Surveillance and Reconnaissance (ISR)
Missile Defense
Chairman & CEO: Daniel P. Burnham
2002 Revenue
$16.8 Billion
62% of sales to U.S. Department of Defense
79,000 employees worldwide
Headquarters located in Lexington, MA
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5. Client Contact Brian Scott B.S.E. in Mechanical Engineering at NAU
M.S. in Mechanical Engineering at UofA
Employee of Raytheon since graduation
Missile Systems – Future Combat Systems
Tucson, Arizona
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6. Problem Statement
A preliminary design and a proof-of-principal prototype are needed for a window positioning system to be used in a tank-launched projectile. The device must position a small germanium window into an infrared sensor’s optical path to perform Non-Uniformity Compensation.
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7. Project Requirements NUC Mechanism must:
Survive 10KG launch acceleration normal to the window face
Packaged in 0.235” thick by 2.89” diameter cylinder, excluding electronics
Move a 0.50” x 0.44” x 0.04” thick Germanium lens to cover a photocell array
Require less than 24 Watts at a maximum of 24 Vdc for less than 1 second
Move lens in and out of the field of the array in less than 1 second, and remain in position for 1 second
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8. What Is Infrared Imaging
Light at frequencies below visible red are considered infrared
All objects emit infrared energy at ordinary temperatures
Objects with higher temperatures emit more infrared energy
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9. Infrared Seeker Operation
Modern “Heat Seekers”:
Employ advanced infrared sensor arrays
Utilize computer programs to select, target, and guide munitions towards specific images
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10. Non-Uniformity Compensation (NUC)
NUC is necessary to adjust for different pixel sensitivities which could cause erroneous targeting by seeker computer
Germanium Lens Moved in Front of IR Array
Raw IR Image before NUC
Blurred IR Image with Lens in Position
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11. Non-Uniformity Compensation (NUC)
Computer algorithm adjusts gain factors of individual pixels so that a uniform image results from a uniform scene
NUC
Germanium Lens Moved
Out of Position
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12. Seeker Head Layout
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13. Rail Gun Test
155mm Howitzer fires projectile into water filled trough to provide firing conditions and “soft catch capability
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14. Acceleration Time Histories
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15. Acceleration Definition
Launch Conditions
Set Back 10,000G
Set Forward 2,000G
Lateral Balloting 3,300G
Flight Conditions
Lateral: 0-3G
Vibration: 5G
Set Forward
Set Back
Lateral Balloting
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16. Scope of Design Constraints
One quarter subjected to 10,000 G’s weighs
approximately 120 lbs.
The restricted thickness of the available volume is less than ¼ of an inch
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17. Design Philosophy K.I.S.S. Keep close contact with client
Minimize complexity of the design to reduce probability of failure
Keep close contact with client
Bring attention to potential design problems before it’s too late
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18. Design Process Brainstorming - Mechanism ideas
Mechanism Selection - Based on size constraints
Modeling - Cardboard & CAD models to assess geometries
Analysis - Hand calculations, Adams, COSMOS/M
Fabricate Prototype – CNC
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19. Final Design Frame Solenoid Positioning Arm Pin Bushing Return Spring
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20. Final Design

21. Frame Design Frame supports components and other seeker optics
Modified to eliminate unnecessary weight
Recessed regions for return spring and counterweight clearance
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22. Frame Design Frame 6061-T6 Aluminum Sult = 45 ksi
CNC work done by R&D Specialty Manco
Phoenix, Arizona

23. Selected Solenoid 3 VDC pulling solenoid Electro Mechanisms, Inc
Commercially available PO-25
Fits within required dimensions
Provides minimum of 2 oz. of force at 3X nominal voltage (18 Watts)
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24. Positioning Arm Positioning Arm Bushing Pin 7075-T6 Aluminum
Sult = 82.7 ksi
Bushing
Oilite Bronze - Oil Impregnated
Self Lubricating Bushing
Pin
AISI 4130 Steel
Sult = 106 ksi

25. Pin Connection Design Press Fit Withstands 120lb Vertical Force
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26. Analysis Justification
Deformation of surfaces are within tolerances defined by the optical engineer
Deformation of support structure for optics is within tolerance and creates no interference
No yielding through cross section of part
No ultimate failures occur
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27. Analysis Focus Static Analysis Dynamic Analysis
Pin joint withstands launch accelerations
Arm deflection does not produce ultimate failure
Dynamic Analysis
Solenoid and spring actuation times
Verification of solenoid adequacy
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28. Finite Element Analysis
COSMOS/M
3-D 20 Noded Quadrilateral Elements
Body (Acceleration) Load
Modeled Positioning Arm & Components
7075-T6 Al Arm
Germanium Lens
Oilite Brass Bushing
Tungsten Counterweight
Material properties specified for each component
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29. FEA Mesh

30. Von Mises Stress Plot smax = 80.3 ksi F.S. = 1.03
Does Not Yield Through Cross-Section
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31. Dynamic Analysis
Adams software used for dynamic analysis w.r.t. arm rotation
Employed actual solenoid force function curve and spring force
Analysis Performed:
Actuation & return times
Forces due to snubbing of arm rotation
Verification of solenoid strength sufficiency over entire actuation distance
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32. Adams Simulation
Actuation time = sec
Spring Return = sec

33. Prototype Cost Cost Per Unit $ 341.96 TOTAL $ 683.92
Machine Work & Parts
Frame (2)
Arm (2)
Pin & Bushing (2)
Solenoids (14)
Solenoid Screws (144)
Miscellaneous (Spring, Wire, etc.) $ $ $ $ $ $
TOTAL $
Cost Per Unit $
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34. Total Project Spending
Modeling Supplies $
Prototype Cost $
Documentation $
Presentation Supplies $
Travel & Miscellaneous $
TOTAL
$1,905.92
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35. Project Budget Provided Funds by Raytheon Total Project Spending
$ 3,000
Total Project Spending
$ 1,906
Donation to the College of Engineering & Technology
$ 1,094
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36. Time Log Total Project Hours for Spring Semester 684.5 hrs
Avg. Hours Per Team Member: hrs
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37. Conclusion
The balanced swing arm design is simple and efficient in providing the required lens motion while withstanding the environmental constraints
A prototype that meets project specifications will be delivered to Raytheon on time and within budget
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38. Acknowledgements Brian Scott Dr. Ernesto Penado, Advisor
Raytheon Missile Systems
Dr. Ernesto Penado, Advisor
Dr. David E. Hartman, P.E.
Dr. John Tester
NAU Machine Shop
Don McCallum, Daniel, & Rus
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39. Questions?