- API data.nasa.gov | Last Updated 2018-07-19T08:08:25.000Z
<p>Collision avoidance for unmanned aerial systems (UAS) traveling at high relative speeds is a challenging task. It requires both the detection of a possible collision and deployment of an appropriate maneuver to avoid it, to be done in few seconds or less. NASA Langley and Boston University are engaged in a collaborative effort to design neuromorphic optic flow algorithms to avoid collisions and embed these algorithms in small, low-weight, and low-power customized hardware solutions in UAS.<p/><p>Using biologically-inspired neuromorphic optic flow algorithms is a novel approach in collision avoidance for UAS. Traditional computer vision algorithms rely on solving nonlinear partial differential equation systems to estimate optic flow which is a computationally expensive task. Neuromorphic algorithms instead make use of lessons learned in biology to solve these problems in a more efficient manner. An example is the fly's motion detector, which can be modeled by a system that uses a set of locally calculated, parallel spatio-temporal correlations for a set of velocities determined by the input sampling rates and flying speeds. Correlation results are interpreted as likelihood for a motion direction and speed. Stages of obstacle detection and tracking can temporally and spatially integrate these likelihoods to increase the signal-to-noise ratio, and in turn the detection rate. In addition to its computational efficiency, the proposed neuromorphic solution is more stable and noise tolerant than solving a nonlinear optimization problem. Even if single computational nodes get corrupted due to functional or structural failures in the hardware, the performance of appropriately designed parallel, distributed neuromorphic algorithms degrades gracefully. Neuromorphic algorithms are commonly implemented using software running on general-purpose multicore/graphic processing unit systems. This approach, though flexible, can have significant overhead in terms of power, performance, and is not easily portable across platforms, therefore reducing its scope of applicability. In the second phase, we will port the neuromorphic algorithms to field programmable gate arrays (FPGAs) and application specific integrated chips (ASICs). This will allow us to meet demanding performance requirements needed in UAS such as fast processing, low weight, low power consumption, as well as robustness to hardware failure.</p>
- API data.nasa.gov | Last Updated 2018-07-20T06:54:34.000Z
New wind tunnel flow quality test and analysis procedures have been developed and will be used to establish standardized turbulent flow quality measurement techniques and data reduction procedures for future flow quality studies in the National Transonic Wind Tunnel (NTF) and other Aeronautics Test Program (ATP) facilities. To date, few measurements have been made of the characteristics of freestream turbulence in transonic wind tunnels, and details of the amplitude and spectra of freestream velocity and pressure fluctuations is lacking. Consequently, there is an urgent need for in-situ measurements to determine flow quality and the performance of turbulence and noise suppression devices. This information is required if we are to accurately assess and characterize ground test facility performance. To meet these challenges, a unique research program is proposed to clarify and alleviate the aerodynamic problems associated with adverse wind tunnel flow quality. It combines innovative advances in data base assessment and management, and new approaches to turbulence instrumentation and analysis. Standardized turbulence measurement techniques and data analysis procedures will be established and used to document the flow quality in our major test facilities.
- API data.nasa.gov | Last Updated 2018-09-05T23:04:12.000Z
The current International Space Station (ISS) ECG (electrocardiogram) system for donning the biomedical sensors is time consuming and inconvenient, requiring shaving, application of electrodes, and signal checks. A more efficient ECG system will save crew time and reduce the overhead of stowing additional supplies. Additionally, the current ECG hardware requires dedicated ISS power and significant volume, but advances in microelectronics has significantly reduced the volume and power required for ECG applications. The Biosensors-EMSD (Exploration Medical System Demonstration) will demonstrate the integration of small, battery powered, easy to use biomedical sensors and data acquisition devices that will have the ability to measure, store, and transmit physiologic parameters during operational and ambulatory scenarios. Specific Aims: 1. Demonstrate that commercial off the shelf (COTS) and emerging technologies satisfy exploration physiological monitoring requirements and operational requirements 2. Reduce the time required of an on-orbit crew and ground personnel to store, access, transfer, and process physiological data 3. Provide a mechanism for interfacing biomedical sensor technology with a common data management framework and architecture to enable the EMSD objectives. The functionality of the ECG system will be verified through a ground demonstration and an ISS flight demonstration, both as part of the Exploration Medical System Demonstration. The project will begin with a market survey of available COTS ECG systems that meet physiological monitoring requirements followed by a direct COTS procurement. The ECG system will then be tested and verified for proper capabilities by CMO analogs. Ground testing will require CMO analogs to don the ECG system and execute a series of predetermined tasks while a variety of ECG data and video is collected. ECG data and video will be examined to ensure data quality, appropriate data routing, and to demonstrate system efficiency. Flight testing will be similar to ground testing, but may not be as comprehensive given in-flight resource limitations. The availability of more varied medical condition simulations, more extensive supply of power, fewer time and space limitations, and enhanced system characterization capabilities will allow the ground demonstration to expand the on-orbit objectives by assessing system effectiveness and performance.
Two-Dimensional Differential Deposition and Erosion for Thin-Shell Figure Correction, and Non-Distorting, High-Energy X-ray Multilayersdata.nasa.gov | Last Updated 2018-09-07T17:46:47.000Z
We propose to continue our development of two-dimensional differential deposition and erosion, a novel methods for high-throughput surface height error correction in thin-shell cylindrical mirror substrates. We also propose to develop non-distorting X-ray reflective multilayer coatings for use above 80 keV. Our specific research objectives are: (a) develop two-dimensional control of film deposition and erosion to correct both low- and mid-frequency surface height errors in cylindrical, thin-shell mirror substrates, and (b) develop high-efficiency, non-distorting, zero net-stress, and stress balanced, reflective multilayer coatings for use above 80 keV.
Rapid Electrochemical Detection and Identification of Microbiological and Chemical Contaminants for Manned Spaceflight Projectdata.nasa.gov | Last Updated 2018-07-18T20:05:27.000Z
<p>A great deal of effort has gone into the development of point-of-use methods to meet the challenge of rapid bacterial identification for both environmental monitoring and clinical applications.&nbsp; Unfortunately, most of the methods developed rely on Preliminary Chain Reaction (PCR) and face inherent limitations because of the requirement for enzymatic components and thermal control.&nbsp; Other methods based on surface plasmon resonance, quartz crystal microbalance, and fluorescence has been reported with good detection limits, but, these methods are immunological and cannot provide genetic-level information.&nbsp; Further, they require labeled markers, complicated fluid handling systems, and sensitive optics that drive up cost and complexity and preclude them from outside the laboratory.&nbsp; Recent work by a group at the University of Toronto has focused on developing an electrochemical platform that combines ultrasensitive detection, straightforward sample processing, and inexpensive components to create a cost-effective, user-friendly device for detection and identification of microorganisms.&nbsp; The platform combines an electrical cell lysis chamber, and electrochemical reporter system, and nanostructured microelectrodes (NMEs) to detect specific nucleic acid sequences.&nbsp; The nucleic acid sequences are unique to a given type of microorganism and can be used to identify the microorganisms present in a sample.</p><p>From the perspective of the anticipated prototype device &nbsp;(Lam, et al. 2012. <em>Polymerase Chain Reaction-Free, Sample-to-Answer Bacterial Detection in 30 Minutes with Integrated Cell Lysis</em>. Anal. Chem. <strong>84(1)</strong>: 21-5), detection of microbial contaminants will begin with a lysis chamber designed to release DNA and RNA from microorganisms present in the sample using ultrasonic or electrochemical technology.&nbsp; The DNA and RNA mixture is then passed into an analysis chamber containing an array of nanostructured microelectrodes (NMEs).&nbsp; The surface of the NMEs will be functionalized with probe molecules for DNA or RNA sequences specific to the bacteria being targeted.&nbsp; Binding of the DNA or RNA to the appropriate detection probe on the NME surface in the presence of an electrochemical reporter system will change the electrochemical properties of the NMEs.&nbsp; A potentiostat is used to measure the current at each individual electrode before and after addition of the DNA and RNA mixture.&nbsp; The difference in current before and after addition of the mixture to the NMEs is compared against a pre-determined threshold to check for the presence of target bacteria in the sample.&nbsp; The process for detection of chemical contaminants is very similar.&nbsp; The lysis chamber would be bypassed and the sample would flow directly into the analysis chamber.&nbsp; The NMEs will be functionalized with molecules to selectively bind the desired targets (analytes) and the change in the electrochemical response of each NME can again be used to detect and quantify the contaminants.&nbsp; Depending on the analyte of interest, it may be possible to directly measure analyte binding on the surface of the NMEs without the use of an electrochemical reporter system. The overall project will focus on optimization of the individual aspects of the detection platform in preparation for construction of a prototype for a flight experiment.&nbsp; The scope of the work in this proposal is limited to characterization and optimization of the lysis step/sample preparation, probe selection, and NME structure.&nbsp; Lysis conditions will be optimized by evaluating parameters associated with the oscillation frequency and lysis time for ultrasonic techniques and applied voltage for the electrochemical techniques.&nbsp; Cell viability, as determined by fluorescent detection of DNA or R
- API data.nasa.gov | Last Updated 2018-07-19T09:50:29.000Z
The primary objective of the Phase I investigation is to develop and demonstrate an innovative solution that can enable very high precision pointing accuracy (<0.08 degree nominal; <0.03 degree extended goal) at fast slew rates; providing part of a advanced Smallsat/CubeSat precision attitude determination and control system (PADCS) that can meet emerging very stringent missions requirements. The Phase I program aim is to design and fabricate initial prototype hardware, including power electronics and Reaction Wheel Assembly (RWA) modifications as to demonstrating such positional accuracy capability, power cost (peak and average power consumption), slew rates and mass/volume cost of the new solution. A critical objective of Phase I will be to develop at the decoupled control architecture for the new multi-stage Attitude Control System ACS controller that will be modeled, simulated, and then converted to hardware prototype for Phase I assessments. This goal is to integrate this prototype controller into a multi-stage (ACS) design hardware emulation testbed and evaluate actual performance before conclusion of the program.
- API data.nasa.gov | Last Updated 2018-07-19T09:42:19.000Z
Fault Management (FM) is one of the key components of system autonomy. In order to guarantee FM effectiveness and control the cost, tools are required to automate fault-tree generation and updates based on design models specified in standardized design languages such as AADL. Accordingly, we propose a fault tree generation and augmentation environment (FTGA). Equipped by a fault class model and an FM method catalog, FTGA evaluates not only failure behavior in the application under analysis but also FM's capability and adequacy for failure mitigation. Moreover, when an inadequacy in FM is revealed during fault tree generation or analysis, the fault tree will be allowed for augmentation through FM method insertion and be followed by a quantitative evaluation for FM effectiveness validation. Therefore, unlike traditional fault tree analysis which plays a passive role in FM, the automated FTGA environment actively and explicitly influence system design and updates, enabling "fault-tree-in-the-loop" for a system's life cycle. Further, by separating its generic functions (which we collectively call "shared package") from design-language-specific functions (which we collectively call "interface package"), FTGA will be an extensible modeling environment. The anticipated results from the Phase I project will be a preliminary prototype of FTGA and a demonstration for concept validation.
- API data.nasa.gov | Last Updated 2018-07-19T08:10:09.000Z
Polymer reinforced composite parts required for heavy lift launch vehicles are currently fabricated by hand lay-up or automated tape lay-up followed by curing using heat, pressure, vacuum and inert atmosphere. Composite structures for future applications are expected to be larger than 9 meters in diameter and greater than 10 meters in length. Such large composite structures cannot be fabricated by regular autoclaving processes because of limitations of the size of autoclaves and high costs associated with energy consumption. In this Phase I effort, MMI will develop a novel out-of-autoclave processing method for the fabrication of nanostructured polymer matrix composites for fabrication of light weight structural parts of large dimensions. This phase of research will also involve a system analysis of the technology to identify the benefits and target areas of use. A correlation study based system analyses will provide a path to apply the fabrication methods to fabricate large composite parts used in aircraft structures. Phase II will scale up the technology and demonstrate property enhancements. The resin infusion process proposed will be suitable for economical manufacture of large parts. The nanocomposite reinforcement proposed will also afford better mechanical properties to the polymer matrix composite.
Application of Advanced Electromagnetic Arrays to High Efficiency, High Bandwidth, Redundant Linear Actuators, Phase IIdata.nasa.gov | Last Updated 2018-07-19T13:23:00.000Z
There is a need to develop electromechanical actuators to improve performance beyond that of hydraulic devices currently being used in numerous aerospace and industrial applications. Beginning with NASA-provided performance specifications, this Phase I SBIR effort has employed a systems approach to develop and optimize the design of an electromechanical linear actuator appropriate for demanding launch vehicle thrust vector and control surface applications. The actuator system design consists of a high-efficiency permanent magnet motor with redundant current channels for system fault tolerance, multiple high-bandwidth controllers that are matched to motor characteristics, and a compact roller-screw mechanism, along with housing and supporting elements. A system of innovations was necessary to overcome the inherent limitations of today's electromechanical actuators, which were developed based on the limitations of traditional motors, power electronics, and available actuator hardware. The projected weight of the actuator prototype to be built in Phase II is less than the existing hydraulic systems currently in use by NASA, and half of previous electric prototypes having the same performance specification. Working with a major aerospace company partner, the Phase II Team will deliver a tested prototype actuator system as a basis for future advanced commercial products.
Combining Discrete Element Modeling, Finite Element Analysis, and Experimental Calibrations for Modeling of Granular Material Systems, Phase Idata.nasa.gov | Last Updated 2018-07-19T18:14:06.000Z
The current state-of-the-art in DEM modeling has two major limitations which must be overcome to ensure that the technique can be useful to NASA engineers and the commercial sector: the computational intensive nature of the software, and the lack of an established methodology to determine the particle properties to best accurately model a given physical system. The proposed work will address both of these limitations. We will look at two approaches to overcome the particle count limitations of DEM: investigate the scaling up of particle size; and combine FEA and DEM to look at problems of densely packed solids. We will explore regimes where DEM and FEA are applicable and establish a coupling methodology that can be further developed during phase II. To address the lack of an established methodology to determine the particle properties to best accurately model a given physical system, we will investigate several small scale experiments that can be used to characterize DEM models. The proposed work will advance the state-of-the-art in DEM. At the end of phase I we will show the feasibility of developing modeling approaches to overcome the main limitations of DEM.