Army 17. 1 Small Business Innovation Research (sbir) Proposal Submission Instructions

REFERENCES:

1. B. Culpin, D.A.J. Rand. Failure modes of lead/acid batteries, Journal of Power Sources, Volume 36, Issue 4, 16 December 1991, Pages 415-438

2. DOE Handbook, Primer On Lead-Acid Storage Batteries, DOE-HDBK-1084-95 September 1995

3. ATPD-2406A, US Army TACOM Purchase Description: Battery Monitoring System, 14 March 2013, 63 pages (uploaded in SITIS on 1/4/17).

4. MIL-PRF-32143B, Performance Specification Batteries, Storage: Automotive Valve Regulated Lead Acid (VRLA), 5 October, 2011

KEYWORDS: lead acid battery, diagnostics, capacity, cold cranking amps, prognostics, battery monitoring, battery failure, 6T format, battery life, battery status

A17-024

TITLE: HPC enabled FDTD Channel Modeling for Dense Urban Scenes in the HF/VHF Band

TECHNOLOGY AREA(S): Information Systems

OBJECTIVE: This SBIR focuses on the development of highly efficient Finite-Difference-Time-Domain (FDTD) propagation codes that are portable onto high performance computer (HPC) clusters for applications at High Frequency (HF) and Very High Frequency (VHF) bands, for the development of mobile ad hoc radio networks.

DESCRIPTION: It is anticipated that future Army operations will take place in increasingly dense urban environments, so called mega-cities, as well as in other challenging scenarios comprised of significant clutter and man-made structures. In such environments, lower frequency operations, e.g., low VHF, offers significant propagation advantages, especially for short-range low-power operation [1]-[4]. This is due to the high penetration of such signals through multiple barriers and walls, with relatively little signal distortion. The studies have shown that the low frequency channels have excellent potential for applications supporting dismounts and autonomous platforms, providing persistent communications and geolocation capabilities with minimal infrastructure and low transmit power in challenging Army relevant scenarios [4],[5].

While there are computationally efficient and accurate propagation models for the Ultra High Frequency (UHF) and microwave bands, especially outdoors, the lower frequency bands present a unique set of challenges because conventional propagation modeling techniques are inaccurate in these bands. Full-wave FDTD based solutions, which directly solve Maxwell’s equations in time domain, provide an accurate method to predict the spatial signal variation in the presence of inhomogeneous clutter. However, application of FDTD is currently limited to electrically small scale scenes due to their computationally complex nature. The objective of this SBIR is the development of efficient codes to provide a new capability in this regime, for the accurate study of propagation channels and consequent development of systems. On a single computer, current state-of-the-art FDTD codes can solve a 3D scene with a maximum number of cells of roughly 10 million [6]. Also, existing codes offer limited flexibility in terms of handling various realistic feature-rich scene geometries and material properties. The codes developed as a result of this SBIR should at least double the computational efficiency of the state-of-the-art solver both in terms of speed and memory required for computation. They should also have high fidelity and provide scene generation capabilities to simulate a variety of realistic urban scenarios.

FDTD parallelization via domain decomposition offers one approach to reducing computational complexity without sacrificing accuracy. For example, a very large physical scene can be decomposed into a number of smaller domains and distributed among many nodes of HPC cluster. At each time step of the FDTD computation, each node updates the fields in its subdomain, and all the subdomains are then combined. Also, for large-scale scenarios, one can often identify parts that may not interact with each other, for example due to large free-space separation. In such cases, it is possible to decompose the scene into uncoupled substructures, simulate each substructure separately, and then superimpose the contributions of all substructures coherently using algorithms inspired by the fast multipole (FMM) method.

The main research questions to be investigated include: 1) devising efficient codes compatible with and scalable on HPC platforms, 2) the ability to simulate realistic complex 3D scenes such as dense urban, e.g., including high-rise structures with subterranean space, 3) provide spatially dense propagation predictions throughout the environment including amplitude and phase (not just path loss), 4) enable the use of such codes for fast simulations of mobile networks, 5) incorporate emerging miniaturized antenna models as well as enable the study of arrays on transmit and receive, 6) ability to import terrain data in various formats and standards, and 7) incorporate parametric models of urban scenes for rapid scene geometry reconfiguration. Urban scenes should include interior and exterior features, realistic material properties, and infrastructure. The codes should be flexible to accommodate the HF/VHF bands and beyond.

PHASE I: The Phase I study will focus on specification of appropriate propagation models and expansion of the models to large scene analysis compatible with high performance computers. This will also include selection of appropriate scenarios for modeling and study, such as dense urban, forest, tunnel and other relevant highly cluttered environments. The Phase I study will include estimation of accuracy and performance tradeoffs, and incorporation of antenna models, terrain data as well as various types of sources including plane-wave sources and lumped source of arbitrary user-defined sources.

PHASE II: Phase II will consist of implementation and testing of the propagation codes in increasingly large scale scenes. Validation will be carried out to the degree possible through theoretical and experimental means. The Phase II deliverables include documented flexible codes with feature-rich models of urban structures (incorporating realistic geometries and relevant material properties) with high fidelity for adoption into Army and DoD research. A key aspect of this phase is optimization of the code for large scene simulations with the goal of at least doubling the computational efficiency of the state-of-the-art full wave solver.

PHASE III DUAL USE APPLICATIONS: Phase III will yield a commercialized code that can be adapted to a variety of scenarios, for both military and civilian applications. The end-state of this research must result in a final code that would readily be utilized by the Army to solve relevant problems such as fast simulations of mobile networks in large scale complex urban/indoor scenarios with accurate geometries and material properties. The contractor should work with Army scientists and engineers as well as commercial partners, to identify and implement technology transition to the military (e.g. CERDEC & USSOCOM) and for civilian applications such as Macro and pico-cell deployment (Qualcomm) and deployment of emergency communications and tracking systems in austere infrastructure-poor environments.

The final codes developed as a result of this SBIR should at least double the computational efficiency of the state-of-the-art solver both in terms of speed and memory required for computation in addition to being easily portable and scalable on HPC platforms. It should also have features to generate and reconfigure feature-rich urban and indoor scene geometries and material properties as well as incorporate actual terrain data into the model. While it is anticipated that Army future operations will need to contend with dense urban settings, there currently does not exist highly accurate and large-scale propagation models at low frequencies, to efficiently and accurately predict performance when indoors or surrounded by dense clutter. These codes will provide unprecedented new capability to study, understand, and design systems that will provide persistent communications, control, and geolocation in dense urban settings. This especially includes indoor/outdoor operation, with one-hop connectivity deep into buildings.

REFERENCES:

1. F. Dagefu, G. Verma, J. Choi, B. Sadler, and K. Sarabandi, “Low-Power Low-Frequency Communications in Complex Environments with Miniature Antennas,” IEEE Antennas and propagation Magazine, submitted for publication, January 2016

2. F. Dagefu, G. Verma, C. Rao, P. Yu, B. Sadler, K. Sarabandi, “Short-Range Low-VHF Channel Characterization in Cluttered Environments”, IEEE Transactions on Antennas and Propagation, vol. 63, no. 6, pp. 2719-2727, June 2015

3. F. Dagefu, J. Choi, M. Sheikhsofla, B. M. Sadler, K. Sarabandi, “Performance assessment of lower VHF band for short-range communication and geolocation applications,” Radio Science Journal, June 2015

4. F. Dagefu, J. Choi, M. Sheikhsofla, B. M. Sadler, K. Sarabandi, “Performance assessment of lower VHF band for short-range communication and geolocation applications,” Radio Science Journal, June 2015

5. Jungsuek Oh ; Jihun Choi ; Dagefu, F.T. ; Sarabandi, K.; “Extremely Small Two-Element Monopole Antenna for HF Band Applications,” IEEE Transactions on Antennas and Propagation, Volume: 61 , Issue: 6, 2013

6. Retrieved from: http://www.speag.com/products/semcad/solutions/

7. F. Dagefu, K. Sarabandi, “Analysis and Modeling of Near-Ground Wave Propagation in the Presence of Building Walls,” IEEE Transactions on Antennas and Propagation, Volume: 59, Issue: 6, Part: 2, 2011

KEYWORDS: Radio propagation, low frequency, VHF, FDTD models, HPC based propagation modeling

TECHNOLOGY AREA(S): Materials/Processes

OBJECTIVE: The objective of this effort is to develop portable conformal rechargeable solid state high energy storage devices for soldiers with enhanced safety and reduced weight.

DESCRIPTION: Battery energy storage has become a critical component in military operations because of the rapidly growing demands of the power-consuming systems carried by the soldiers on the battlefield. Currently utilized batteries are flammable and suffer from insufficiently high specific energy, which create safety and tactical burden for the soldiers. The use of solid state batteries may offer enhanced safety and increased energy density. However, current solid state technology typically relies on metallic lithium anode, which cannot be rapidly charged or discharged at low temperatures and is additionally unsafe if exposed to air or water upon accidental disassembling of a cell case. This effort seeks proposals that demonstrate conformal solid state lithium batteries that operate in a wide range of thermal conditions with excellent cyclic performance, provide high rate performance compatibility, low inherent materials and systems safety risks with anodes other than metal foil. The conformal battery is a thin, lightweight, flexible battery that conforms to the desired shape. Scalable low-cost manufacturability is also of great importance.

PHASE I: The Contractor shall develop anode, cathode, solid state electrolyte and conduct physical testing and qualification to provide clear evidence for the feasibility of the Phase II lithium cell. Developed technology should be feasible to produce full cells of size greater than 0.25 Ah. The milestone will include a solid state cell prototype with the unit stack (current collectors, electrodes, and electrolyte) specific energy > 250 Wh/kg and energy density > 600 Wh/l. Cell flexibility should exceed state of the art at the same energy density.

PHASE II: By the end of Phase II development of materials and manufacturing methods is expected to lead to a conformal lithium solid state cell with the following deliverables: (1) technology demonstration for the full solid state cells of 12 V, 150 Wh total energy that will operate within -40 to + 60 degrees C and provide cell-level specific energy > 350 Wh/kg and energy density > 800 Wh/l when operating at room temperature at a discharge rate of C/2. Energy density is based upon weight of current collectors, electrodes, and electrolyte. This cell should also exhibit cycle life of at least 250 cycles (> 80% of initial capacity) and survive storage at temperatures from -55 to +80 degrees C. (2) A concept design of the scalable manufacturing of such cells. In addition, abuse tolerance testing is highly desired for shock, nail testing and other methods to test for fire and explosion risks.

PHASE III DUAL USE APPLICATIONS: Safe conformal high energy density, high power energy storage systems have dual use for both military and civilian applications. Wide temperature range required will satisfy stringent environmental requirements for military power sources for storage and during transportation. A concept design of the scalable manufacturing of such cells developed in Phase II shall be applied for manufacturing of the large format batteries and commercializing developed technology.

Developed lithium batteries can be used as power sources for quick reaction munitions, soldier-portable systems, distributed sensor systems, etc. in the battlefield. The environmental requirements for military power sources may include their use at extreme hot and cold temperatures, exposure to dust, wind, snow and high levels of shock and vibration both in use and during transportation. Army temperature, specific energy, power and cycle life requirements are, however, different from the requirements for the civilian battery for transportation applications and portable indicating a niche market for the developed product.

REFERENCES:

1. Zhou, G., Li, F. & Cheng, H.-M. Progress in flexible lithium batteries and future prospects. Energ Environ Sci 7, 1307-1338, doi:10.1039/C3EE43182G (2014)

2. Conformal Wearable Battery: http://www.cerdec.army.mil/news_and_media/Conformal_Wearable_Battery/

3. Nitta, N., Wu, F., Lee, J. T. & Yushin, G. Li-ion battery materials: present and future. Materials Today 18, 252-264, doi:http://dx.doi.org/10.1016/j.mattod.2014.10.040 (2015)

4. Palacín, M. R. & de Guibert, A. Why do batteries fail? Science 351, doi:10.1126/science.1253292 (2016)

KEYWORDS: energy storage, solid state battery, conformal battery, reducing logistical burden for soldiers

TECHNOLOGY AREA(S): Battlespace

OBJECTIVE: Develop technologies to embed ARL’s Automated Impacts Routing into autonomous multi-rotor platform technology to automatically inform navigation processes.

DESCRIPTION: Military swarming is often encountered in asymmetric warfare where opposing forces are not of the same size, or capacity. In such situations, swarming involves the use of a decentralized force against an opponent, in a manner that emphasizes mobility, communication, unit autonomy and coordination or synchronization. [1]. On a future battlefield, Commanders will deploy intelligent autonomous systems that can function in a swarm-like mentality, working in a synchronized manner to deploy necessary force or gather intelligence that would otherwise not be available. It is envisioned in 2040 that these intelligent autonomous systems (IAS) will pervade the battlefield. These systems must rapidly sense, react, and learn from the environment in which they function. Just as biological systems have adapted to the environment, so must the future IAS. Technologies to ensure an efficient, effective and survivable system must be developed. These capabilities must include: harvesting atmospheric energy for sustained power; innovative techniques to quickly sense and "blend" with the atmospheric background and perceive a threat; and, determine and mitigate environmental effects on an IAS or a swarm of IASs. We must develop technologies that allow autonomous systems to learn and adapt to these type of changes in the environment, specific to Army operations. This capability will empower U.S. forces to maximize environmental situational awareness and understanding, with minimal or no human involvement.

Multi-rotor autonomous system technology already exists, where the user can program a flight route into the on-board system and allow the system to fly without additional interface. As a first step in developing a total autonomous system for battlefield operations, it will be necessary for the system to understand the environment that it is flying through and then make educated decisions based on that information.

The Army has developed decision aid technology that is able to ingest current atmospheric data or atmospheric forecast data. With that information, an optimized route through the atmospheric threats (as well as other Battlespace obstacles) is created for the operator to navigate. With this technology (the Army’s Automated Impacts Routing (AIR) system) added to the embedded system on a multi-rotor autonomous system, the platform will be able to ingest environmental data, execute AIR to generate an optimized route, then change the systems navigation waypoint to a more optimized position along the total planned flight path. The multi-rotor systems would then be considered environmentally intelligent. Specific to Army, this system will make use of existing and future Battlespace technologies including Intelligence, Reconnaissance, and Surveillance (ISR) information as part of the Battle Command Network. The complete intelligence picture including weather will then drive the path optimization of the multi-rotor platform.

PHASE I: Develop on-board embedded system/processor(s), which can run Army-developed Automated Impacts Routing (AIR) system which will generate an optimized path through the grid for use by the IAS. The optimized path output generated by AIR is in Open Geospatial Consortium (OGC)-compliant Keyhole Markup Language (KML) format, and can be selected as “path-only” or “path and impacts grid” output format for use by the embedded system. The embedded system should allow the optimized path generated by AIR to be used to adjust flight control systems within the IAS, thus providing a safer flight path along which the IAS is moving to conduct mission operations. Additionally, show the potential for the embedded system to ingest high resolution atmospheric model data. The model data will be on the order of 300MB for a 100kmx100km domain, 1km grid spacing hourly forecast with forecasts out to 3 hours. Thus, model data frequency is expected to be approximately 300MB/hr. Demonstrate prototype embedded system running AIR and using AIR output to adjust flight control systems of IAS. Threshold; demonstrate on bench, output dataset for one valid time from model data as input into AIR, AIR is run and adjusts flight controls. Objective; demonstrate input of multiple time steps in the model data (forecast for three different time steps) into AIR, AIR output adjust flight controls for each time step, in flight.

PHASE II: Develop and demonstrate system implementing technology developments achieved in Phase I. Verify data collected by onboard embedded system. Demonstrate system collecting high-resolution model data, generating impacts grid(s) and those grids being processed onboard by AIR. Additionally, demonstrate onboard atmospheric sensor data collection, impacts grid generation and processing similar to the use of high-resolution model data. The sensor data size and frequency is sensor-dependent, but on the order of the sampling frequency of a very small form factor meteorological sensor. Data size/frequency requirements further refined from Phase I test results. Threshold; demonstrate input of multiple time steps in the model data (forecast for three different time steps) into AIR, AIR output adjust flight controls for each time step, in flight. Objective; in addition to threshold criteria, demonstrate ability to use onboard sensor data.

PHASE III DUAL USE APPLICATIONS: The contractor shall integrate the Phase II approach into one or more systems/software applications for eventual fielding. Deliver final developed system, including prototype and all software technology to Army for immediate use with current Army research-level forecast models. Commercial applications include use in autonomous systems for home delivery of packages (i.e Amazon) or autonomous systems such as Google’s car for street view images.

REFERENCES:

1. Edwards, Sean J.A. (2000). Swarming on the Battlefield: Past, Present, and Future. Rand Monograph MR-1100. Rand Corporation. ISBN 0-8330-2779-4

2. Johnson, JO (2015) Automated Impacts Routing (AIR): Standalone Desktop Application User's Guide, ARL Technical Report (ARL-TR-7398)

3. Johnson, JO (2011) Atmospheric Impacts Routing (AIR), ARL Technical Report (ARL-TR-5792)

KEYWORDS: UAV, UAS, intelligent autonomous systems, atmospheric effects, automated impacts routing, weather, uncertainty, decision making, forecast, decision tool, high resolution, embedded systems

TECHNOLOGY AREA(S): Electronics

OBJECTIVE: To develop and demonstrate integrated circuits required to obtain highly linear and efficient transmitters at mm-wave frequencies.

DESCRIPTION: The recent proliferation of battlefield sensors and unmanned platforms capable of collecting broadband data (video, audio, etc.) has led to greater situational awareness, monitoring, and information gathering. It has also increased the demand for information throughput beyond the capacity of current commercial and military communication systems. The ever increasing demands on information throughput (multi-gigabit per second) can be easily met by moving the operating frequencies towards the mm-wave range. At the same time, the rapid advancement in semiconductor technology has reduced the cost of mm-wave integrated circuits considerably. Moreover, significant progress has been made in developing harmonically-optimized highly efficient linear power amplifier architectures. These factors have stimulated interest in developing breakthrough high performance, linear, high-efficiency mm-wave electronics. The current architectures suffer from substantial energy-efficiency degradation at deep power back off. In addition, the nonlinearities have limited the use of the electronics to low spectral efficiency modulation schemes. As a result, the throughput has been limited to 1 GB/s combined with high energy consumption. Thus, the electronics has been custom tailored to each application and cannot be used as a "common module re-configurable" sub-system. The current size, weight, power, and cost (SWaP-C) has limited the use of mm-wave circuits to large platforms.

The development of linear broadband mm-wave transmitters will greatly improve the communications bandwidth. Based on Shannon’s capacity limit, increasing the bandwidth automatically reduces the required energy per bit for the same information throughput. This leads to longer battery life and greater mobility for soldiers and units. In addition, linear operation enables higher order modulation leading to greater spectral efficiency further adding to battery energy savings.

This program seeks the development of inexpensive (i.e. highly-integrated), frequency-agile, energy-efficient, ultra-linear mm-wave transmitter architecture and implementation. The transmitter should meet the following design targets: (1) the saturated output power should exceed 1 Watt (higher output power is desirable), (2) the operating frequency band should be 10 GHz (or more) with a minimum center frequency of 30 GHz, (3) the peak efficiency should be comparable with state of the art (in the technology chosen) and the efficiency at 6 dB back-off should be greatly enhanced over the classical class-B efficiency, (4) the linearity (measured with adjacent channel power ratio, ACPR, where the adjacent channel is 1.5 times the symbol rate from the center frequency) should be better than 35 dBc at 3 dB back-off from P1dB (power at 1 dB compression), and (5) the data rate should exceed 5 GB/s (giga-bit per second). Ideally, the transmitter can support multiple (greater than 2 or 3) modulated carriers simultaneously. The transmitter needs to readily interface with standard 50-ohm components, and to tolerate voltage standing wave ratio (VSWR) up to 1:2. The local oscillator can be internally generated or supplied from outside. The transmitter input will be base-band in-phase / quadrature (I and Q) modulation data.