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Approximate Cartesian Control for Robotic Tool Usage with Graceful Degradation Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:31:39.000ZMany of NASA's exploration scenarios include important roles for autonomous or partially autonomous robots. It is desirable for them to utilize human tools when possible, rather than needing to build custom tools for each robot. Control of robotic manipulators for tool usage generally requires a very precise Cartesian-space trajectory of the tool tip (e.g., moving a marker along the surface of a whiteboard or rotating a screwdriver about an axis). Well-known techniques exist for manipulator control in Cartesian space, most of which necessitate solving a series of Inverse Kinematics (IK) problems. Closed-form IK solvers work well for 7-degree-of-freedom (DOF) arms with rigid tool attachments, but cannot handle non-rigid tools that slip in the robot's hands. Numerical IK approaches are more generic and can handle non-rigid links to tools, but can be slow to converge. More importantly, if any joints fail or become limited in their range of motion, the robot arm essentially becomes 6-DOF or lower. IK solvers often fail in these lower DOF spaces because the configuration space becomes non-continuous and full of "holes". As a result, a 7-DOF robotic arm in space might be rendered largely useless if a single joint fails or even loses mobility until it can be serviced. TRACLabs proposes to investigate an alternative approach to traditional Cartesian control approaches, which rely on complex IK solvers that go from Cartesian space backwards to joint space. We propose to leverage cheap memory and modern processing speeds to instead perform simple computations that go from joint space forwards to Cartesian space. Such techniques should overcome common changes to a manipulation chain caused by tool slippage or the grasping of a new tool and to overcome uncommon changes to a chain caused by joint failures, reduced joint mobility, changes in joint geometry or range of motion, or added joints.
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Surface Turbulent Fluxes, 1x1 deg Daily Grid, Set1 V2c
nasa-test-0.demo.socrata.com | Last Updated 2015-07-19T08:49:10.000ZThese data are the Goddard Satellite-based Surface Turbulent Fluxes Version-2c (GSSTF2c) Dataset recently produced through a MEaSUREs funded project led by Dr. Chung-Lin Shie (UMBC/GEST, NASA/GSFC), converted to HDF-EOS5 format. The stewardship of this HDF-EOS5 dataset is part of the MEaSUREs project, http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects/surface-turbulent-fluxes-esdr http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects GSSTF version 2b (Shie et al. 2010, Shie et al. 2009) generally agreed better with available ship measurements obtained from several field experiments in 1999 than GSSTF2 (Chou et al. 2003) did in all three flux components, i.e., latent heat flux [LHF], sensible heat flux [SHF], and wind stress [WST] (Shie 2010a,b). GSSTF2b was also found favorable, particularly for LHF and SHF, in an intercomparison study that accessed eleven products of ocean surface turbulent fluxes, in which GSSTF2 and GSSTF2b were also included (Brunke et al. 2011). However, a temporal trend appeared in the globally averaged LHF of GSSTF2b, particularly post year 2000. Shie (2010a,b) attributed the LHF trend to the trends originally found in the globally averaged SSM/I Tb's, i.e., Tb(19v), Tb(19h), Tb(22v) and Tb(37v), which were used to retrieve the GSSTF2b bottom-layer (the lowest atmospheric 500 meter layer) precipitable water [WB], then the surface specific humidity [Qa], and subsequently LHF. The SSM/I Tb's trends were recently found mainly due to the variations/trends of Earth incidence angle (EIA) in the SSM/I satellites (Hilburn and Shie 2011a,b). They have further developed an algorithm properly resolving the EIA problem and successfully reproducing the corrected Tb's by genuinely removing the "artifactitious" trends. An upgraded production of GSSTF2c (Shie et al. 2011) using the corrected Tb's has been completed very recently. GSSTF2c shows a significant improvement in the resultant WB, and subsequently the retrieved LHF - the temporal trends of WB and LHF are greatly reduced after the proper adjustments/treatments in the SSM/I Tb's (Shie and Hilburn 2011). In closing, we believe that the insightful "Rice Cooker Theory" by Shie (2010a,b), i.e., "To produce a good and trustworthy 'output product' (delicious 'cooked rice') depends not only on a well-functioned 'model/algorithm' ('rice cooker'), but also on a genuine and reliable 'input data' ('raw rice') with good quality" should help us better comprehend the impact of the improved Tb on the subsequently retrieved LHF of GSSTF2c. This is the Daily (24-hour) product; data are projected to equidistant Grid that covers the globe at 1x1 degree cell size, resulting in data arrays of 360x180 size. A finer resolution, 0.25 deg, of this product has been released as Version 3. The GSSTF, Version 2c, daily fluxes have first been produced for each individual available SSM/I satellite tapes (e.g., F08, F10, F11, F13, F14 and F15). Then, the Combined daily fluxes are produced by averaging (equally weighted) over available flux data/files from various satellites. These Combined daily flux data are considered as the "final" GSSTF, Version 2c, and are stored in this HDF-EOS5 collection. There are only one set of GSSTF, Version 2c, Combined data, "Set1" It contains 9 variables: "E" 'latent heat flux' (W/m**2), "STu" 'zonal wind stress' (N/m**2), "STv" 'meridional wind stress' (N/m**2), "H" 'sensible heat flux' (W/m**2), "Qair" 'surface air (~10-m) specific humidity' (g/kg), "WB" 'lowest 500-m precipitable water' (g/cm**2), "U" '10-m wind speed' (m/s), "DQ" 'sea-air humidity difference' (g/kg) "Tot_Precip_Water" 'total precipitable water' (g/cm**2) The double-quoted labels are the short names of the data fields in the HDF-EOS5 files. The "individual" daily flux data files, produced for each individual satellite, are also available in HDF-EOS5, although from differe...
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Ceramic Composite Mechanical Fastener System for High-Temperature Structural Assemblies Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:24:27.000ZUnder Phase I, the feasibility of a novel thermal stress-free ceramic composite mechanical fastener system suitable for assembly of high-temperature composite structures was successfully demonstrated. The innovative 2-dimensional (2D) fastener design facilitates joining load-bearing hot structural assemblies and can be produced at a cost much lower than other competing designs and methods. Functional SiCf/SiCm composite fasteners having two (2) fiber reinforcement orientations of 0/90-degrees (cross-ply) and 145-degrees (bias-ply) were fabricated for characterization. Testing of the respective fasteners included both axial tension and single-lap shear. The cross-ply reinforced SiCf/SiCm fasteners exhibited axial tensile and single-lap shear strengths of 38.0 and 33.1 ksi, respectively. The bias-ply fasteners exhibited axial tensile and single-lap shear strengths of 31.3 and 29.8 ksi, respectively. Using a generalized analytical method for determining the distribution of forces and stresses in the 2D mechanical fastener developed in Phase I, optimized configurations will be designed and produced in Phase II for evaluation. The metallic subcomponents used for Phase I demonstration will be produced using a high temperature-capable material (e.g., ceramic, superalloy). Aerodynamically smooth Cf/SiCm and SiCf/SiCm composite structural lap joints will be assembled using the optimized composite fastener system for characterization. Testing of the lap joint assemblies will performed to determine the flexibility and structural efficiency of the joint as a function of off-axis loading relative to the principal axis of the fasteners. Elevated temperature testing will be performed to establish the effects of temperature on the mechanical properties of the joint.
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Designer's Situation Awareness Toolbox (DeSAT) Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:22:49.000ZThis SBIR will develop a design decision support tool that will assist designers in providing a powerful, supportive work environment for aviation crews that support the maintenance of a high level of situation awareness in the flight environment. DeSAT will be developed as a design decision support system providing the capability to (1) analyze the situation awareness requirements associated with operational requirements (which could include ground based or flight based crew members), (2) compare situation awareness information requirements to system design features to identify potential situation awareness problems and deficiencies early in the design process, and (3) evaluate the degree to which design concepts support SA via the Situation Awareness Global Assessment Technique (SAGAT). DeSAT will be developed for analysis of SA for both individual crew stations and for distributed teams operating across flight and time. DeSAT will allow designers to modify design concepts early in the design process to ensure that they provide the needed situation awareness to system users.
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Increasing NASA SSC Range Safety by Developing the Framework to Monitor Airspace and Enforce Restrictions Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:39:58.000Z<p>Engine testing at NASA SSC poses a significant risk to general aviation due to potential smoke and excessive turbulence. The airspace over Stennis has been designated as restricted from 0600 - 2300 at altitudes below 5000 feet. SSC has limited ability to detect aircraft that have breeched the restricted airspace. In order to protect lives and property, a systematic evaluation of the potential technologies was requested to identify and define options to monitor the airspace, warn aircraft of impending danger, warn NASA test operations, and if necessary provide NASA test operations data so that an informed, timely decision could be made on whether or not to interrupt engine tests. This project systematically evaluated potential technologies that could address the problem of unauthorized aircraft entering Restricted Airspace/R-4403; a primary focus of this activity was on protecting the SSC Fee and Buffer Zone during an engine test or other sensitive operation. The research began with the findings and technology identified in the SSC Facility Safety Assessment Report. In 2010, a Facility Safety Assessment was performed for SMA to identify hazards associated with the SSC multiuser test range. During this assessment, a top system level safety hazard concerning unauthorized aircraft entering the SSC Restricted Airspace during test range operations, as well as twelve other hazards that directly or indirectly relate to the top hazard, were identified. SSC has limited ability to detect aircraft that may have intentionally or unintentionally breached R-4403. Because the restricted airspace is controlled by Houston ARTCC, controllers at Gulfport-Biloxi International Airport (GPT) and Louis Armstrong New Orleans International Airport (MSY) are not required to monitor or alert aircraft to avoid R-4403.</p><p>The purpose of the project was to evaluate monitoring techniques to address the problem of aircraft entering R-4403, primarily focusing on access to the SSC Buffer Zone during an engine test or other sensitive operation. The objective was to provide a small set of cost effective solutions that enable appropriate personnel to make informed safety decisions in near-real time. A number of different existing and prototype technologies were considered against the monitoring requirements defined by NASA.</p><p>During this project, several different types of aircraft monitoring technologies were investigated. The project intended to prototype these potential technology solutions based on information and assessments performed. Potential software approaches to be prototyped included: phone apps, e-mail alerts, and desk top displays. Each was assessed against NASA&rsquo;s airspace monitoring requirements, which included the ability to monitor the entire buffer zone plus an additional 5 mile radius for both transponder and non-transponder equipped aircraft and, if possible, low-altitude UASs. Some technologies were eliminated because they are unable to track non-transponder equipped aircraft, while others are not capable of operating in all weather and illumination conditions. The remaining technologies represent potential solutions to monitoring the restricted airspace at SSC.&nbsp;Ultimately, the technologies investigated were not required and a refined notification procedure to follow in advance of test operations was implemented to insure NASA SSC Range Safety.</p><p>&nbsp;</p>
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Predictive Situational Awareness Tool Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:09:28.000ZSituational Awareness is the key element of performing safe and effective operations, and the space vehicle operations carried out by NASA is by no means an exception to the rule. Astronauts and flight controllers need to maintain awareness of the situation in the space vehicles, robots, habitats, Mission Control Center, and other systems. NASA has devoted and continues to devote a significant amount of resources to software for displaying the current situation in order to maintain this awareness. However, astronauts and flight controllers need to predict the future state of the systems for themselves. What will happen next? Resources have now advanced to the point where it is possible to inform the astronauts and flight controllers of the expected situation in the near future, and also to warn them if the current situation does not match the expectations of the recent past?this will indicate a developing issue that requires attention. All of this will aid in reducing the cognitive load on the astronauts and flight controllers, and help them perform their work safely and effectively. S&K Aerospace, LLC (SKA) proposes to research and develop a system that will provide predictive situational awareness to flight controllers and astronauts, by bringing together information about the current state of the vehicles and other systems, the activities planned in the near future, and the expected state of the system in the future, as well as an indication if the current state of the system matches planned state. This system will be called the Predictive System Awareness Tool, or PSAT.
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Surface Turbulent Fluxes, 1x1 deg Daily Grid, Set1 V2c
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T04:51:34.000ZThese data are the Goddard Satellite-based Surface Turbulent Fluxes Version-2c (GSSTF2c) Dataset recently produced through a MEaSUREs funded project led by Dr. Chung-Lin Shie (UMBC/GEST, NASA/GSFC), converted to HDF-EOS5 format. The stewardship of this HDF-EOS5 dataset is part of the MEaSUREs project, http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects/surface-turbulent-fluxes-esdr http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects GSSTF version 2b (Shie et al. 2010, Shie et al. 2009) generally agreed better with available ship measurements obtained from several field experiments in 1999 than GSSTF2 (Chou et al. 2003) did in all three flux components, i.e., latent heat flux [LHF], sensible heat flux [SHF], and wind stress [WST] (Shie 2010a,b). GSSTF2b was also found favorable, particularly for LHF and SHF, in an intercomparison study that accessed eleven products of ocean surface turbulent fluxes, in which GSSTF2 and GSSTF2b were also included (Brunke et al. 2011). However, a temporal trend appeared in the globally averaged LHF of GSSTF2b, particularly post year 2000. Shie (2010a,b) attributed the LHF trend to the trends originally found in the globally averaged SSM/I Tb's, i.e., Tb(19v), Tb(19h), Tb(22v) and Tb(37v), which were used to retrieve the GSSTF2b bottom-layer (the lowest atmospheric 500 meter layer) precipitable water [WB], then the surface specific humidity [Qa], and subsequently LHF. The SSM/I Tb's trends were recently found mainly due to the variations/trends of Earth incidence angle (EIA) in the SSM/I satellites (Hilburn and Shie 2011a,b). They have further developed an algorithm properly resolving the EIA problem and successfully reproducing the corrected Tb's by genuinely removing the "artifactitious" trends. An upgraded production of GSSTF2c (Shie et al. 2011) using the corrected Tb's has been completed very recently. GSSTF2c shows a significant improvement in the resultant WB, and subsequently the retrieved LHF - the temporal trends of WB and LHF are greatly reduced after the proper adjustments/treatments in the SSM/I Tb's (Shie and Hilburn 2011). In closing, we believe that the insightful "Rice Cooker Theory" by Shie (2010a,b), i.e., "To produce a good and trustworthy 'output product' (delicious 'cooked rice') depends not only on a well-functioned 'model/algorithm' ('rice cooker'), but also on a genuine and reliable 'input data' ('raw rice') with good quality" should help us better comprehend the impact of the improved Tb on the subsequently retrieved LHF of GSSTF2c. This is the Daily (24-hour) product; data are projected to equidistant Grid that covers the globe at 1x1 degree cell size, resulting in data arrays of 360x180 size. A finer resolution, 0.25 deg, of this product has been released as Version 3. The GSSTF, Version 2c, daily fluxes have first been produced for each individual available SSM/I satellite tapes (e.g., F08, F10, F11, F13, F14 and F15). Then, the Combined daily fluxes are produced by averaging (equally weighted) over available flux data/files from various satellites. These Combined daily flux data are considered as the "final" GSSTF, Version 2c, and are stored in this HDF-EOS5 collection. There are only one set of GSSTF, Version 2c, Combined data, "Set1" It contains 9 variables: "E" 'latent heat flux' (W/m**2), "STu" 'zonal wind stress' (N/m**2), "STv" 'meridional wind stress' (N/m**2), "H" 'sensible heat flux' (W/m**2), "Qair" 'surface air (~10-m) specific humidity' (g/kg), "WB" 'lowest 500-m precipitable water' (g/cm**2), "U" '10-m wind speed' (m/s), "DQ" 'sea-air humidity difference' (g/kg) "Tot_Precip_Water" 'total precipitable water' (g/cm**2) The double-quoted labels are the short names of the data fields in the HDF-EOS5 files. The "individual" daily flux data files, produced for each individual satellite, are also available in HDF-EOS5, although from differe...
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Extension of an Object Oriented Multidisciplinary Analysis Optimization (MDAO) Environment Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:41:31.000ZMultidisciplinary design, analysis, and optimization (MDAO) tools today possess limited disciplines with little fidelity modeling capability. These tools are typically developed as a single large software application that performs analysis for all disciplines but has little or no capability to integrate multi-fidelity and multi-discipline components that have already been developed as stand-alone analysis codes. Even though a multitude of tools have been developed and well adapted to the interdisciplinary aircraft design/analysis, they have not been developed to work together. The objective of the development of the MDAO tool is to generate a "central executive" that can integrate disparate software packages in a cross platform network environment so as to perform optimization and design tasks in a cohesive streamlined manner. This object-oriented framework can integrate the analysis codes for multiple disciplines, instead of relying on one code to perform the analysis for all disciplines. ZONA Technology and its team member Virginia Polytechnic Institute propose to develop three object-oriented components that will fully leverage tools currently under development within NASA's MDAO framework. The three major components are: (1) an automatic re-meshing tool that can provide a fast and efficient mesh generation capability for complex structures like curved panels with curved stiffeners and aircraft wings of any shape with curved spars and ribs. (2) a hybrid optimization tool that combines a non-gradient based optimization method and a gradient based optimization method. The advantage of this hybrid optimization is that a global optimum point can be achieved through the non-gradient optimization and acceleration of the convergence can be obtained by aiding gradient based optimization algorithm. (3) a fast transonic unsteady aerodynamics method for accurate aeroelastic analysis and shape sensitivity information due to the change of external wing shape.
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Multi-Cluster Network on a Chip Reconfigurable Radiation Hardened Radio Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:18:34.000ZThe objective of the Phase-I research is to architect, model and simulate a multi-cluster Network on a Chip (NoC) reconfigurable Radio in SystemC RTL, with throughput up to 1Gbps. The architecture is based on mapping key Radio DSP operations onto clusters of 2D-Grid networks of primitive computation agents. The primitives in each cluster consists of multiply, accumulate and CORDIC operations. RISC agents and a primary RISC provide for reconfigurability. All agents are individually accessible for testing and configuration. The reconfigurable radio trades throughput for power by turning off primitive agents, using subsets of agents and routing links. Key agents that require SEU immunity for robust operation are identified and registers are implemented with Rad Hard temporal latch technology. The radio is reconfigurable for both beamforming and open-loop MIMO-OFDM operation with variable length FFTs to meet throughput/range requirements. The chip area and power is drastically reduced by maximum reuse of primitive agents by taking advantage of orthogonality between DSP operations. In Phase-II an NoC with support for 4x4 MIMO-OFDM will be synthesized on IBM 90nm process using Rad Hard agents and routing links that can be reconfigured for 4x1,4x2 and 4x4 MIMO-OFDM and single carrier operation, including FPGA emulation.
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High-Frequency Flush Mounted Miniature LOX Fiber-Optic Pressure Sensor II Project
nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:43:28.000ZLuna Innovations has teamed with the University of Alabama, Huntsville, to develop a miniature flush-mounted fiber-optic pressure sensor that will allow accurate, high-frequency high-pressure measurement of LOx and LH2. The Innovation of this proposed development is that the miniature flush-mounted fiber-optic pressure sensor is not intrusive, is intrinsically safe, and is a novel adaptation of proven technology. To insure compatibility with the LOx environment, the sensor has been constructed from metal-oxides, ceramics and other materials that are intrinsically safe. The sensor will help engineers optimize performance of liquid fueled rocket engines for the next generation of reusable lift vehicles, and flight versions of the sensors will enable real-time monitoring and control of the engines, improving safety and enabling commercialization of space. During the Phase I, prototype sensors were demonstrated in Liquid Oxygen (LOx) at temperatures of -196<SUP>o</SUP>C. The sensor was able to measure pressures over 1000 psi and transients exceeding 4500 psi/sec rates of change without failure. During the Phase II, optimized thermally compensated sensors will be constructed and extensive tests conducted to advance the technology to pre-production status. This system meets NASA's goals by providing LOx and LH2 pressure data while: 1) minimizing intrusion, 2) improving reliability, 3) having fast response time, and 4) being intrinsically safe.