480 likes | 798 Views
Raytheon Seekers. Infrared Seeker Calibration Mechanism. Raytheon Seekers. Aaron Scrignar……Team Leader Eric Draves………..Historian Trevor Moody…….Web Page Des., Mediator Stacy Davison……..Document Coord., Financial Officer LaTanya Williams…Communicator. Presentation Outline.
E N D
Raytheon Seekers Infrared Seeker Calibration Mechanism Raytheon Seekers
Raytheon Seekers Aaron Scrignar……Team Leader Eric Draves………..Historian Trevor Moody…….Web Page Des., Mediator Stacy Davison……..Document Coord., Financial Officer LaTanya Williams…Communicator Raytheon Seekers
Presentation Outline • Client Description • Problem Definition • What is Infrared Imaging? • Project Requirements • Design Method • Prototype Design • Analysis Process • Project Spending • Time Log • Conclusion Raytheon Seekers
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 Raytheon Seekers
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 Raytheon Seekers
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. Raytheon Seekers
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 Raytheon Seekers
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 What Is Infrared Imaging Raytheon Seekers
Infrared Seeker Operation • Modern “Heat Seekers”: • Employ advanced infrared sensor arrays • Utilize computer programs to select, target, and guide munitions towards specific images Raytheon Seekers
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 Raytheon Seekers
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 Raytheon Seekers
Seeker Head Layout Raytheon Seekers
Rail Gun Test • 155mm Howitzer fires projectile into water filled trough to provide firing conditions and “soft catch capability Raytheon Seekers
Acceleration Time Histories Raytheon Seekers
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 Raytheon Seekers
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 Raytheon Seekers
Design Philosophy • K.I.S.S. • 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 Raytheon Seekers
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 Raytheon Seekers
Final Design • Frame • Solenoid • Positioning Arm • Pin • Bushing • Return Spring Raytheon Seekers
Frame Design • Frame supports components and other seeker optics • Modified to eliminate unnecessary weight • Recessed regions for return spring and counterweight clearance Raytheon Seekers
Frame Design • Frame • 6061-T6 Aluminum • Sult = 45 ksi • CNC work done by R&D Specialty Manco • Phoenix, Arizona
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) Raytheon Seekers
Positioning Arm • Positioning Arm • 7075-T6 Aluminum • Sult = 82.7 ksi • Bushing • Oilite Bronze - Oil Impregnated • Self Lubricating Bushing • Pin • AISI 4130 Steel • Sult = 106 ksi
Pin Connection Design Press Fit Withstands 120lb Vertical Force Raytheon Seekers
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 Raytheon Seekers
Analysis Focus • Static Analysis • Pin joint withstands launch accelerations • Arm deflection does not produce ultimate failure • Dynamic Analysis • Solenoid and spring actuation times • Verification of solenoid adequacy Raytheon Seekers
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 Raytheon Seekers
Von Mises Stress Plot smax = 80.3 ksi F.S. = 1.03 Does Not Yield Through Cross-Section Raytheon Seekers
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 Dynamic Analysis Raytheon Seekers
Actuation time = 0.027 sec Spring Return = 0.028 sec Adams Simulation
Prototype Cost Cost Per Unit $ 341.96 Raytheon Seekers
Total Project Spending Raytheon Seekers
Project Budget • Provided Funds by Raytheon • $ 3,000 • Total Project Spending • $ 1,906 • Donation to the College of Engineering & Technology • $ 1,094 Raytheon Seekers
Time Log Total Project Hours for Spring Semester 684.5 hrs Avg. Hours Per Team Member: 136.9 hrs Raytheon Seekers
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 Raytheon Seekers
Acknowledgements • Brian Scott • Raytheon Missile Systems • Dr. Ernesto Penado, Advisor • Dr. David E. Hartman, P.E. • Dr. John Tester • NAU Machine Shop • Don McCallum, Daniel, & Rus Raytheon Seekers