Department of the navy (don) 18. 1 Small Business Innovation Research (sbir) Proposal Submission Instructions introduction

Beyond the aforementioned military applications, the localization training-acclimation system has strong potential benefits for civilian workplace applications. For instance, in road construction, the localization of horns and backup alarms on moving equipment is critical, and many run-over accidents occur when these warning signals cannot be localized. Furthermore, in manufacturing plants, forklifts and remotely-guided materials handling vehicles have reverse alarms and motion beepers, respectively, to warn workers of their positions. Any worker in these highly dynamic environments must be cognizant of the location of dangerous equipment that moves in their vicinity. Furthermore, these workers are also frequently wearing hearing protection due to noise exposures. Thus, workers need training on the tasks of learning the warning signals, what they mean, and how to localize them. Each worker could go through a brief acclimation session with any hearing protector they are supplied with, and learn to recognize and localize the sounds they will encounter in the actual workplace. With fairly simple injection of relevant warning signals into the system software, and calibration of these signals acoustically, the training system can easily be adapted for specific workplaces with relevant warning signals as well as ambient sound. Thus, industrial and construction workers, prior to being placed on the job, can become well-informed on the auditory signals to which they must be vigilant, and learn how to localize those signals. Also, the training system can assist in the industrial hygienist's selection of proper hearing protectors that best facilitate the detection and localization of specific industry warning signals such that situation awareness on the part of the worker can be maintained.

REFERENCES:

1. Casali, J. G. and Lee K. (2016) “Objective metric-based assessments for efficient evaluation of Auditory Situation Awareness Characteristic of TCAPS and HPDs, Final Report”. Contract #W81XWH-13-C-0193, Department of Defense, Hearing Center of Excellence, January 14, 2016. (95 pages) (DoD contractor’s report.) http://www.dtic.mil/docs/citations/AD1017344

2. Talcott, K. A., Casali, J. G., Keady, J. P. and Killion, M. C. (2012) “Azimuthal auditory localization of gunshots in a realistic field environment: Effects of open-ear versus hearing protection-enhancement devices (HPEDS), military vehicle noise, and hearing impairment.” International Journal of Audiology, 51, S20-S30.

3. Clasing, J. E. and Casali, J. G. (2014) “Warfighter auditory situation awareness: Effects of augmented hearing protection/enhancement devices and TCAPS for military ground combat applications.” International Journal of Audiology, 52, Suppl 2, S43-52.

4. Scharine, A., Letowski, T., and Sampson, J. B. (2009). “Auditory situation awareness in urban operations.” Journal of Military and Strategic Studies,11(4).

5. Casali, J. G. and Robinette, M. B. (2015) “Effects of user training with electronically-modulated sound transmission hearing protectors and the open ear on horizontal localization ability.” International Journal of Audiology, 54, Suppl 1, S37-45.

6. Fluitt, K., Gaston, J., Karna, V., and Letowski, T. (2010). “Feasibility of audio training for identification of auditory signatures of small arms fire (No. ARL-TR-5413).” Army Research Lab Aberdeen Proving Ground MD, Human Research and Engineering Directorate.

KEYWORDS: Situation Awareness; Auditory; Training; Measurement

N181-085

TITLE: Feed-Forward Controls for Laser Powder Bed Fusion Based Metal Additive Manufacturing

TECHNOLOGY AREA(S): Air Platform, Ground/Sea Vehicles, Materials/Processes

ACQUISITION PROGRAM: 2019 Quality Made FNC

OBJECTIVE: To develop feed-forward control (FFC) hardware, algorithms, and multi-physics-based models to allow real-time tracking of powder bed layer variability and corresponding laser processing compensation to improve the quality of laser fusion-based metal additive manufacturing (AM) parts.

DESCRIPTION: Additive Manufacturing (AM) technologies continue to draw increased engineering interest, with technical advances in multiple fronts including hardware, software, and design processes. AM is finding new applications areas with even a few documented operational demonstrations of fracture critical components, but this is still the exception rather than the rule. Additively manufactured parts still require several trial and error runs with post-processing heat treatments and machining to optimize the build, reduce residual stresses, and meet tolerances. AM still lacks a stable process that can produce consistent, defect-free parts.

One of the reasons for the lack of a stable process is the inherent variabilities at all steps (pre-, in-, and post-processing) of the AM process which tend to produce parts with inconsistent tolerances, mechanical properties, and defects. These variabilities can be broadly classified into random (or aleatoric, fluctuating, statistical) and systematic (predictable, quasi-static, deterministic), primarily depending on the time or length scale at which they occur, and our ability to track and compensate for them. Depending on the nature of the variability (random or systematic), different approaches can be developed to minimize their deleterious effects on part quality. Of the many parameters that could be monitored and controlled, this SBIR topic seeks to develop innovative FFC hardware, software, and multi-physics models with the aim to compensate for the systematic physical property variabilities of the powder bed layer (temperature, mass, absorptivity, heat capacity, thermal conductivity). These variabilities result from the random distribution of the powder particles geometry, the thermal evolution of the part and powder inside the work volume, as well as the systematic layer thickness variability that develops during the AM process caused by splatter, molten particle ejects, and denudation processes, as well as from the previous layer surface roughness. Not being able to anticipate and compensate for these systematic changes in the powder bed tends to produce an inconsistent melt-pool shape and temperature distribution, which leads to non-uniform microstructure and defects such as lack of fusion, keyholes, Marangoni flow surface ripples, porosity, balling, and surface roughness.

Feed-forward control can be performed at multiple levels such as at the track, layer, or part levels. In general, the closer one probes the powder from the melt-pool, the more useful the information will be for purposes of adjusting the processing parameters and compensating for powder property variability. At the same time, the closer one probes from the melt-pool, the less time there will be available to process the information. A balance between the amount of information collected, the data processing time, the system response time, and the proximity to the melt-pool needs to be achieved in order to reliably obtain efficient FFC of the AM process. This SBIR topic will consider all approaches to feed-forward control, but real-time approaches that aim to capture current, relevant information ahead of the melt-pool in the shortest amount of time possible will be favored over those approaches that focus on a track, static layer, or static build method, respectively.

PHASE I: During Phase I, the contractor will define and develop a concept for a FFC system including the hardware, the software, and multi-physics models for real-time tracking and compensation of the powder bed layer physical property variability towards the production of quality AM parts in laser powder bed fusion-based metal AM systems. The Principal Investigator (PI) will also describe how to prepare powder bed test articles with a range of well-defined parameter variables for the purpose of model development, system verification, and eventually for technology validation. The metal powders of interest to the Navy are Ti64, 316L SS, or Inconel 625. During Phase I, the PI will continue to refine the models, improve the hardware, and expand the number of validation tests. The design created in Phase I will result in plans to build a prototype unit in Phase II.

PHASE II: During Phase II, the contractor will complete the purchase of all the components necessary for the development of a feed-forward control system and will start assembling the prototype design. The PI will also develop a strategy for integrating the FFC system into an existing AM unit, unless the PI is developing a completely new AM system with the FFC already integrated into the design. It is highly recommended that the PI team with an OEM of metal powder-based AM systems if the PI does not have access to AM equipment. As part of the final validation, the contractor will fabricate the test articles defined in Phase I and measure the degree of improvement in part quality.

PHASE III DUAL USE APPLICATIONS: If Phase II is successful, the company will be expected to support the Navy in transitioning the FFC metal AM system for Navy use. Working with the Navy, the company will integrate the FFC Metal AM system onto a Navy platform for evaluation to determine its effectiveness. The OEM involved during Phase II will be part of the transition team. Phase III will include defining the FFC system and test coupons for qualification, testing the coupons, and establishing facilities capable of achieving full-scale production capability of Navy-qualified parts. The small business will also focus on identifying potential commercialization opportunities.

REFERENCES:

1. Nassar, A. R., Keist, J. S., Reutzel, E. W., and Spurgeon, T. J. “Intra-layer closed-loop control of build plan during directed energy additive manufacturing of Ti–6Al–4V”. Additive Manufacturing 6 (2015) 39–52. https://edisciplinas.usp.br/mod/resource/view.php?id=241938

2. Hu, D. and Kovacevic, R. “Sensing, modeling and control for laser-based additive manufacturing”. International Journal of Machine Tools & Manufacture 43 (2003) 51–60. http://www.sciencedirect.com/science/article/pii/S0890695502001633

3. Everton, S. K., Hirsch, M., Stravroulakis, P., Leach, R. K., and Clare, A. T. “Review of in-situ process monitoring and in-situ metrology for metal additive manufacturing”, Materials and Design 95 (2016) 431–445. http://www.sciencedirect.com/science/article/pii/S0264127516300995

4. Spears, T. G. and Gold, S. A. “In-process sensing in selective laser melting (SLM) additive manufacturing”. Integrating Materials and Manufacturing Innovation, 2016 (a Springer Open Journal) DOI 10.1186/s40192-016-0045-4.
https://link.springer.com/article/10.1186/s40192-016-0045-4

KEYWORDS: Additive Manufacturing; Feed-Forward Control; Feedback Control; Reliability; Multi-Physics Models

TECHNOLOGY AREA(S): Battlespace, Electronics, Sensors

ACQUISITION PROGRAM: Naval Sea Systems Command 06, Naval Special Warfare (SEA06-NSW)

OBJECTIVE: Develop and transition wide-field-of-view (approximately 114 degrees) goggles, capable of performing both underwater to 100 feet and above water, and containing an internally illuminated display. Goggles need to be able to be cleared if flooded with water, equalize pressure as needed, and either be inherently fog-free, or have a system to eliminate fogging.

DESCRIPTION: In light of an increasingly competitive operational arena, Navy divers need to shed gear weight, increase mobility, and have full situational awareness both underwater and above water. Current diver masks are large and unwieldy, and must be removed and stashed when leaving the water and donning night vision hardware. Given advances in swim goggles and in miniaturization of illuminated displays, it is timely to field a single cross-domain goggle capable of allowing seamless transition from undersea to above. As goggles do not cover the nose, innovations must be implemented to allow flooded goggles to be cleared, underwater pressure to be equalized, and fogging to be eliminated (under and above water). Sensing apparatus and processing packages for situational awareness and augmented reality below and above water already exist, and can feed illuminated displays if built into the goggles. The goggle will need to be roughly comparable in size to ordinary lap swim goggles, and have simple, easy to use controls or mechanisms for clearing, equalization, de-fogging and switching the illuminated display on or off.

PHASE I: Develop a design for a wide-field-of-view, Cross-Domain Goggle with an Integrated, Illuminated Display (CDGIID) and analyze and specify the procedures and hardware for clearing, equalizing and de-fogging the goggles and the illuminated display. Designs should be sufficiently detailed to specify all hardware and materials needed, their availability, how they will be implemented, and overall goggle weight. External signals for the illuminated display can either be via industry-standard connector (e.g., no bigger than USB3), or via Bluetooth or similar, or both. Goggles must stand up to typical special operations skydiver and underwater diver handling. The design created in Phase I should lead to plans to build a prototype unit in Phase II.

PHASE II: Fabricate, lab-test, and provide for form, fit, and function by operational Navy divers both below and above water. Within the period of performance, revise the design and refabricate an additional 10 units based on feedback.

PHASE III DUAL USE APPLICATIONS: Create a marketing plan for reaching recreational users and fabrication via 3D printing to bring the per unit cost down to two to three hundred dollars.

REFERENCES:

1. Google. “Glass Explorer Edition”. https://developers.google.com/glass/

2. Mims, Christopher. “High-resolution displays for regular eyeglasses could put Google Glass to shame, be available in one year”. Quartz. 10 Dec 2013. https://qz.com/156203/high-resolution-displays-for-regular-eyeglasses-could-put-google-glass-to-shame-be-available-in-one-year/

KEYWORDS: Goggles; Scuba Diving; Skydiving; Parachuting; Heads Up Display; Illuminated Display

TECHNOLOGY AREA(S): Air Platform, Ground/Sea Vehicles

ACQUISITION PROGRAM: PMW 770 Multi-Function Mast (OE-538) ACAT III

OBJECTIVE: Develop a coating or material that can absorb radio frequency (RF) radiation across the Very Low Frequency (VLF) through Ultra High Frequency (UHF) band yet can be tuned to allow a relatively narrow range of frequencies (e.g., 3-30MHz) to pass. Demonstrate that the coating or material can be applied to a metallic surface such as a submarine mast.

DESCRIPTION: The submarine fleet within the U.S. Navy has been successful in a wide range of missions. For many of these missions, success or failure depends on the submarine’s ability to be stealthy and remain undetected by opposing forces. While submerged, maintaining stealth is relatively easy as most electromagnetic (EM) waves (radio, radar, visible light, etc.) experience high attenuation when propagating through water. However, this high attenuation of EM waves also means communications with submarines is more challenging than with other naval platforms. The Navy employs a variety of methods to communicate with submerged submarines, but the methods used today are generally low data rate, one-way, and/or compromise stealth. As a result, the preferred way to conduct high data-rate two-way communications is for the submarine to come to periscope depth and deploy a communications mast. Unfortunately, once the mast is deployed, it can be detected by radar. For this reason, reduction of the mast’s Radar Cross Section (RCS) is of high importance.

The goal of this topic is to produce a material or coating that will absorb most RF signals yet can be tailored to allow the desired communications frequencies to pass. Such a material would reduce the RCS of the mast, which will reduce the likelihood of detection by opposing forces, without degrading communications. In fact, it would likely improve communications as it would prevent unwanted out-of-band signals from entering the antenna and distorting the incoming communications signal.

The final product of this topic will be a material or coating that absorbs RF radiation and can be applied to the outside surface of a submarine mast such as the OE-538 [11]. The application process needs to be relatively simple and safe for the personnel applying it. For example: if the material can be applied to the outside of the mast in a manner similar to paint or wall paper that would be considered acceptable. Application process that would require the removal of the mast from the submarine would be considered too complicated. It will need to be rugged enough to withstand the mast’s operating environment without falling off or degrading the mast. Environmental conditions to be mindful of include salt water corrosion, water pressure at depth, and temperature/humidity at the surface. In addition, the coating/material will need to have an RF frequency response similar to a bandpass filter that can be adjusted (during manufacturing) for any arbitrary frequency range across the VLF through UHF band. This will allow the desired communications signals to penetrate the mast and be received by the mast antennas, yet will prevent radar reflections.

PHASE I: Identify a coating or material that exhibits the best RF absorption yet can be tuned during manufacturing to allow any arbitrary range of frequencies to pass. Demonstrate and quantify RF absorption and transmission performance over a range of frequencies in a laboratory environment. Verify through simulation and modeling that the coating/material can be manufactured so that the passband can be varied across any frequency range in the VLF through UHF band. Simulated results should be compared to laboratory results to demonstrate the credibility of the model. Define the process for applying the coating/material. Develop prototype plans for Phase II.

PHASE II: Develop and optimize the prototype coating or material identified in Phase I. The final coating/material should have sufficient transmission across the passband so that communications are not degraded, yet absorption at all other frequencies is maximized. Produce multiple samples of the optimized material, each one tuned to a different passband. Demonstrate the tunability of the passband by measuring the frequency response of each sample in a laboratory environment. Confirm that the measured passband is consistent with the expected passband. This will demonstrate that the passband of the material can be deliberately set to the desired frequency range (i.e., “tuned”). Demonstrate the application process on material similar to, if not identical to, the outer material on the OE-538 mast antenna. Show that the application process is simple, safe, and does not damage the mast. Confirm the durability of the coating/material by exposing it to salt water, temperature extremes, humidity, etc. Qualitatively confirm durability through visual inspection of the coating after environmental exposure. Note any visual indications of damage (peeling, flaking, cracking, etc.) Quantitatively confirm durability by repeating RF absorption and transmission measurements.

PHASE III DUAL USE APPLICATIONS: Deliver final coating or material to a Navy facility in sufficient quantity for testing on an OE-538 antenna. Support initial application of material to OE-538 antenna. Support Government laboratory testing and Environmental Qualification Testing.

Commercial uses of this material could include: 1) application to wallets and/or clothing to protect radio-frequency identification (RFID) chip in credit cards or passports from hackers, and 2) application to walls of homes (to include houses and apartments) to prevent neighbors from piggybacking on Wi-Fi channels.

REFERENCES:

1. Cheng, E. M., Malek, F. et al. "The Use of Dielectric Mixture Equations To Analyze The Dielectric Properties Of A Mixture Of Rubber Tire Dust And Rice Husks In A Microwave Absorber." Progress In Electromagnetics Research, Vol. 129, 559-578, 2012 2. http://m.jpier.org/PIER/pier129/29.12050312.pdf

2. Liu, Y. H., Tang, J.M. and Mao, Z. H. "Analysis of bread dielectric properties using mixture equations." Journal of Food Engineering, Vol. 93, 72-79, 2009. http://www.sciencedirect.com/science/article/pii/S0260877408006298

3. Micheli, Davide. "Radar Absorbing Materials and Microwave Shielding Structures Design By using Multilayer Composite Materials, Nanomaterials and Evolutionary Computation." Lambert Academic Publishing, ISBN:978-3-8465-5939-0, 2012 4. https://www.researchgate.net/publication/260018692_Radar_Absorbing_Materials_and_Microwave_Shielding_Structure_Design

4. Tong, X.C. "Advanced Materials and Design for Electromagnetic Interference Shielding." CRC Press, ISBN 978-1-4200-7358-4, 2009. https://www.crcpress.com/Advanced-Materials-and-Design-for-Electromagnetic-Interference-Shielding/Tong/p/book/9781420073584

5. Vinoy, K.J. and Jha, R.M. "Radar Absorbing Materials." Kluwer Academic Press, ISBN 13:978-1-4613- 8065-8, 1996. http://www.worldcat.org/title/radar-absorbing-materials-from-theory-to-design-and-characterization/oclc/36029856

6. Feng, Bo-Kai, "Extracting Material Constitutive Parameters from Scattering Parameters." Naval Postgraduate School, Monterey California, September 2006. http://www.dtic.mil/dtic/tr/fulltext/u2/a456941.pdf

7. Baker-Jarvis, J., Geyer, R. G., and Domich, P. D. "A nonlinear least-squares solution with causality constraints applied to transmission line permittivity and permeability determination." IEEE Transactions on Instrumentation and Measurement, vol. 41, no. 5, pp. 646-652, Oct. 1992. http://ieeexplore.ieee.org/document/177336/

8. Weir, W. B. "Automatic measurement of complex dielectric constant and permeability at microwave frequencies." Proceedings of the IEEE, vol. 62, no. 1, pp. 33-36, Jan. 1974. http://ieeexplore.ieee.org/document/1451312/

9. Chalapat, K., Sarvala, K., Li, Jian and Paraoanu, G. S. "Wideband Reference-Plane Invariant Method for Measuring Electromagnetic Parameters of Materials." IEEE Transactions on Microwave Theory and Techniques, vol. 57, no. 9, pp. 2257-2267, Sep. 2009. http://ieeexplore.ieee.org/document/5204113/

10. “TangiTek CleanSignal™ Technology Evaluation.” U.S. Federal Research Lab Test Report, September 2012. http://www.tangitek.com/downloads/testdata/10-TangiTek-CleanSignal%20Technology%20Evaluation%20Report-FederalLab.pdf

11. Lockheed Martin. “OE-538/BRC Multifunction Communication Mast Antenna System.” 2006. http://cdn.thomasnet.com/ccp/01150582/110349.pdf

KEYWORDS: RF Absorption; Radar Cross Section; RCS; Cosite; Coating; VLF; UHF; Communications; Stealth

TECHNOLOGY AREA(S): Information Systems

ACQUISITION PROGRAM: Digital Modular Radio (DMR), Battle Force Tactical Network (BFTN), HForce

OBJECTIVE: Architect and develop a prototype High Dynamic Range Multi-Carrier Amplifier (HDR MCA) that can support up to 36 concurrent carriers with high individual carrier power variations and the resulting intermodulation interference in the Very High Frequency (VHF) and Ultra High Frequency (UHF) bands.