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DOE OSTI2018

2018 Atmospheric Radiation Measurement (ARM) Annual Report

In fiscal year 2018 (FY2018), the Atmospheric Radiation Measurement (ARM) user facility carried out important measurement missions around the globe and worked to better couple ARM measurements with the needs of the science community through the evaluation of priorities and the continued development of new capabilities, including efforts to better link data and models. While many of these efforts have been ongoing, their importance was supported by recommendations from the 2017 ARM Triennial Review. In February 2018, we submitted the final plans to the U.S. Department of Energy (DOE) that ARM will commit to accomplish over the next two years to address the Triennial Review recommendations. We then began implementing activities to: improve and track communications effectiveness at conferences and through the User Executive Committee implement additional metrics to track ARM’s scientific impact, including on model improvement engage users beyond the traditional DOE Office of Biological and Environmental Research (BER)/Atmospheric System Research (ASR) communities increase the timely production and delivery of ARM Mobile Facility value-added products (VAPs) and create a mechanism to better set expectations for VAP delivery to users improve Data Discovery, ARM’s portal for accessing more than 25 years’ worth of data, for users define a clear process for biennially reviewing instrumentation, data products, and other activities with the goal of determining where resources should be applied update the radar plan and create a plan for optimizing aerosol data collection implement operational plans for the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) project and establish a plan for selecting the next science target for LASSO. We have made great progress in all of these areas, much of which is shared in this report, including plans for setting priorities for aerosol measurements and data product development. In FY2018, ARM also brought many plans to fruition that were outlined in its 2014 Decadal Vision strategy, such as the implementation of the LASSO project that integrates observations and models and the continued advancement in the use of unmanned aerial systems (UAS).

MARCUS, POPEYE, Oliktok Point, Eastern North Atlan↗

DOE OSTI2019

ARM Cloud and Precipitation Measurements and Science Group Charter

The Atmospheric Radiation Measurement (ARM) Cloud and Precipitation Measurements and Science Group (CPMSG) brings together members of the ARM instrument operations, engineering, and translator teams with the ARM science community for the purpose of improving the performance and science impact of the ARM measurements of clouds and precipitation. The members of the CPMSG work toward this goal by confronting science needs from the broader research community with operational constraints of the ARM facility. The CPMSG replaces the former radar science and engineering group. The CPMSG will continue to include a significant focus on the application of the ARM radar network; however, the focus of ARM is ultimately not on specific instruments but on providing measurements and associated data products that advance atmospheric science. Providing measurements of cloud properties has always been a core activity for ARM, but increasingly, ARM has striven to couple measurements of cloud properties with precipitation to support the full range of research associated with cloud systems. Radar measurements are often central to cloud and precipitation research but often the retrieval of cloud and precipitation properties requires coupling radar measurements with measurements from other instruments or other instruments may provide information in physical regimes where radars do not do well. Therefore, the CPMSG will address issues related to radar performance and applications but will also consider issues related to other passive and active remote sensors as well as ground-based in situ precipitation measurements. A driving consideration for the group should be how resources can best be applied to measurements of cloud and precipitation properties and the development of associated data products to increase the scientific impact of these measurements.

Charter, Infrastructure Management Board, User Exe↗

DOE OSTI2019

ARM-Related Unmanned Aerial System (UAS) and Tethered Balloon System (TBS) Operational Requirements and Approval

This procedure addresses the requirements and process for obtaining approval for Unmanned Aerial System (UAS) and Tethered Balloon System (TBS) operations at DOE Office of Science (SC) Atmospheric Radiation Measurement user facility observatories (ARM sites), ARM-supported training flights, atmospheric instrument development flights, and campaigns at non-ARM sites. ARM sites include both ARM observatories and ARM mobile facility deployments. The protection of people, property, and the environment during UAS and TBS operations is the foundation of executing a successful mission using UAS or TBS. This procedure is designed to facilitate safe mission execution. It does not address obtaining approval for ARM-supported research, which is approved through the ARM Field Campaign (AFC) or Engineering Evaluation (EE) processes. Approval of UAS and TBS operations is a prerequisite for final approval of an AFC or EE by the Infrastructure Management Board (IMB) and may be conducted in parallel with preparation and submittal of the AFC or EE proposal to the IMB. This procedure addresses UAS and TBS requirements; mission planning; documentation; maintenance; risk assessment; airworthiness determination; operation approval; training and qualification requirements and responsibilities for UAS remote pilots; TBS operators; visual observers; maintenance technicians; and A&P mechanics. It also addresses the responsibilities of ARM site managers, the Office of Science Aviation Safety Manager, principal investigators, requesting organizations, and Range Safety Officers. This procedure is derived from DOE O 440.2C, Aviation Management and Safety, and Federal Aviation Administration (FAA) Regulations (FARs), 14 CFR 107, and 14 CFR 101. It contains two sections: Section 3.0 addresses UAS operations; Section 4.0 addresses TBS operations.

unmanned aerial systems, tethered balloon systems,↗

DOE OSTI2019

Building the Scale Model TELBOT Master Arm - 19585

For centuries, the art and science of modeling have gone hand in hand with the advancements of technology. Among the most impressive examples of the past modeling were ship models constructed for the British Royal Navy. Referred to as Admiralty models, they were principally constructed during the 18. and 19. centuries to depict proposed warship design. To this day, models are important in the field of engineering, where analytical modeling of a new design needs to be verified. In our project the old practice of building models will be fortified by the most advanced software and 3-D printing technology and used to manufacture a fully working Telbot Master Arm scaled down to 0.4-0.5 of its original size. The Telbot is a robotic arm used in different fields like the nuclear and chemical industry, often in combination with other products of our company. The main features of the Telbot's sleek construction are: 1) the high load capacity design; 2) unlimited rotation of all axes; 3) no external or internal wiring of the arm; 4) unlimited, fast and precise arm movements; 5) smooth and sealed arm bodies and joints; 6) high repeat accuracy; 7) resistance to radiation, and it can handle precise loads from 5 kg to 150 kg. Presently, to demonstrate such impressive design features and movement possibilities to its customers, HWM has to build a 3-D virtual reality simulation of the environment where Telbot is proposed to be used and then the arm simulates its movement in this environment. In addition, though HWM does have a showroom for Telbot, due to its weight and size it is not possible to take the full size Telbot on the road to show off its capabilities to customers. The challenge is to build a scaled down full working version of the Telbot robotic arm that can be moved in every direction and angle. The model will be based on the redeveloped T300 Telbot, with 3 joints and 7 free to move pivots. It will be at a 0.4 or 0.5 scale. The outer shell will be 3D printed. The sensors will forward the position and angle to HWM virtual reality software. With these features, any changes made on the model would get displayed in the software one-to-one. The result will be a Telbot Master arm model which can be easily transported; Waellischmiller would be able to present the Telbot not just virtually, but as a real product with all its functions and versatility and show it all over the world. The extensive construction of the virtual 3-D stimulation can be eliminated and the course of movement to reach specific positions could get simulated faster and easier. It can also be used internally and externally for training. This paper will address the challenges, materials used and manufacturing process of building a fully-working scaled-down version of the Telbot Master Arm. (authors)

3D PRINTING↗

DOE OSTI2017

MARCUS ARM CN and CCN data reprocessed to remove ship exhaust influence

The data presented in this collection are the cloud condensation nuclei (CCN) and condensation nuclei (CN) from the MARCUS (Measurements of Aerosols, Radiation and CloUds over the Southern Oceans) campaign. This campaign involved the deployment of the ARM Mobile Facility aboard the RSV Aurora Australis between October 2017 and March 2018 during its summer season resupplying Australia’s Antarctic research stations from its port in Hobart, Australia. Routine processing undertaken by ARM does not remove platform exhaust associated with its deployment aboard ships. Consequently, the raw data were obtained and manually filtered to remove the influence of platform exhaust on the measurements by reviewing CCN, CN and BC data simultaneously and flagging all affected periods. Remaining data were then quality controlled for when instrument parameters were out of specification. CCN data are split into different streams for supersaturation settings before statistics for each hour being calculated. All data files contain NaN values for periods when data was removed for QC or exhaust reasons. Original raw data available at: Kulkarni, G. R., Flynn, C. and Koontz, A.: Atmospheric Radiation Measurement (ARM) user facility. 2017, updated hourly. Cloud Condensation Nuclei Particle Counter (AOSCCN100). 2017-10-29 to 2018-03-24, ARM Mobile Facility (MAR) Hobart, AUS to Antarctic Coast - resupply ship Aurora Australis; AMF2 (M1)., Atmospheric Radiation Measurement (ARM) user facility Data Center: Oak Ridge, Tennessee, USA [online] Available from: http://dx.doi.org/10.5439/1227964 (Accessed 9 November 2018), 2018. Kuang, C., Salwen, C., Boyer, M. and Singh, A.: Atmospheric Radiation Measurement (ARM) user facility. 2017, updated hourly. Condensation Particle Counter (AOSCPCF). 2017-10-29 to 2018-03-26, ARM Mobile Facility (MAR) Hobart, AUS to Antarctic Coast - resupply ship Aurora Australis; AMF2 (M1)., Atmospheric Radiation Measurement (ARM) user facility Data Center: Oak Ridge, Tennessee, USA [online] Available from: http://dx.doi.org/10.5439/1046184 (Accessed 9 November 2018), 2018.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

2024 Atmospheric Radiation Measurement (ARM) Annual Report

This report provides an overview of the Atmospheric Radiation Measurement (ARM) user facility and a sample of achievements for fiscal year 2024 (FY2024). Strong collaborations between nine DOE national laboratories enable ARM to successfully operate in remote locations around the world. This unique partnership supports the DOE mission to provide for the energy security of the nation. Without the support of the following laboratories, ARM would not be the state-of-the-art facility that it is today. ARM is a multi-laboratory, U.S. Department of Energy (DOE) Office of Science user facility and a key contributor to national and international atmospheric and climate research efforts. ARM offers scientists cutting-edge, ground-based observatories, aerial observation capabilities, and high-performance computing. ARM’s capabilities have enabled more than 30 years of continuous measurements of cloud and aerosol properties and their effects on Earth’s energy balance.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2014

Planning Evaluation of C-Arm Cone Beam CT Angiography for Target Delineation in Stereotactic Radiation Surgery of Brain Arteriovenous Malformations

Purpose: Stereotactic radiation surgery (SRS) is one of the therapeutic modalities currently available to treat cerebral arteriovenous malformations (AVM). Conventionally, magnetic resonance imaging (MRI) and MR angiography (MRA) and digital subtraction angiography (DSA) are used in combination to identify the target volume for SRS treatment. The purpose of this study was to evaluate the use of C-arm cone beam computed tomography (CBCT) in the treatment planning of SRS for cerebral AVMs. Methods and Materials: Sixteen consecutive patients treated for brain AVMs at our institution were included in this retrospective study. Prior to treatment, all patients underwent MRA, DSA, and C-arm CBCT. All images were coregistered using the GammaPlan planning system. AVM regions were delineated independently by 2 physicians using either C-arm CBCT or MRA, resulting in 2 volumes: a CBCT volume (VCBCT) and an MRA volume (V{sub MRA}). SRS plans were generated based on the delineated regions. Results: The average volume of treatment targets delineated using C-arm CBCT and MRA were similar, 6.40 cm{sup 3} and 6.98 cm{sup 3}, respectively (P=.82). However, significant regions of nonoverlap existed. On average, the overlap of the MRA with the C-arm CBCT was only 52.8% of the total volume. In most cases, radiation plans based on V{sub MRA} did not provide adequate dose to the region identified on C-arm CBCT; the mean minimum dose to V{sub CBCT} was 29.5%, whereas the intended goal was 45% (P<.001). The mean volume of normal brain receiving 12 Gy or more in C-arm CBCT-based plans was not greater than in the MRA-based plans. Conclusions: Use of C-arm CBCT images significantly alters the delineated regions of AVMs for SRS planning, compared to that of MRA/MRI images. CT-based planning can be accomplished without increasing the dose to normal brain and may represent a more accurate definition of the nidus, increasing the chances for successful obliteration.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2024

The ATLAS experiment software on ARM

With an increased dataset obtained during the Run 3 of the LHC at CERN and the even larger expected increase of the dataset by more than one order of magnitude for the HL-LHC, the ATLAS experiment is reaching the limits of the current data processing model in terms of traditional CPU resources based on x86_64 architectures and an extensive program for software upgrades towards the HL-LHC has been set up. The ARM architecture is becoming a competitive and energy efficient alternative. Some surveys indicate its increased presence in HPCs and commercial clouds, and some WLCG sites have expressed their interest. Chip makers are also developing their next generation solutions on ARM architectures, sometimes combining ARM and GPU processors in the same chip. Consequently it is important that the ATLAS software embraces the change and is able to successfully exploit this architecture. We report on the successful porting to ARM of the Athena software framework, which is used by ATLAS for both online and offline computing operations. Furthermore we report on the successful validation of simulation workflows running on ARM resources. For this we have set up an ATLAS Grid site using ARM compatible middleware and containers on Amazon Web Services (AWS) ARM resources. The ARM version of Athena is fully integrated in the regular software build system and distributed in the same way as other software releases. In addition, the workflows have been integrated into the HEPscore benchmark suite which is the planned WLCG wide replacement of the HepSpec06 benchmark used for Grid site pledges. In the overall porting process we have used resources on AWS, Google Cloud Platform (GCP) and CERN. A performance comparison of different architectures and resources will be discussed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2014

SpArcFiRe: Scalable automated detection of spiral galaxy arm segments

Given an approximately centered image of a spiral galaxy, we describe an entirely automated method that finds, centers, and sizes the galaxy (possibly masking nearby stars and other objects if necessary in order to isolate the galaxy itself) and then automatically extracts structural information about the spiral arms. For each arm segment found, we list the pixels in that segment, allowing image analysis on a per-arm-segment basis. We also perform a least-squares fit of a logarithmic spiral arc to the pixels in that segment, giving per-arc parameters, such as the pitch angle, arm segment length, location, etc. The algorithm takes about one minute per galaxies, and can easily be scaled using parallelism. We have run it on all ∼644,000 Sloan objects that are larger than 40 pixels across and classified as 'galaxies'. We find a very good correlation between our quantitative description of a spiral structure and the qualitative description provided by Galaxy Zoo humans. Our objective, quantitative measures of structure demonstrate the difficulty in defining exactly what constitutes a spiral 'arm', leading us to prefer the term 'arm segment'. We find that pitch angle often varies significantly segment-to-segment in a single spiral galaxy, making it difficult to define the pitch angle for a single galaxy. We demonstrate how our new database of arm segments can be queried to find galaxies satisfying specific quantitative visual criteria. For example, even though our code does not explicitly find rings, a good surrogate is to look for galaxies having one long, low-pitch-angle arm—which is how our code views ring galaxies. SpArcFiRe is available at http://sparcfire.ics.uci.edu.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2026

ARM Lead Mentor Selection Process

The Atmospheric Radiation Measurement (ARM) Program was created in 1989 with funding from the U.S. Department of Energy (DOE) to develop several highly instrumented ground stations to study cloud-formation processes and their influence on radiative transfer. This scientific infrastructure provides for fixed sites, mobile facilities, an aerial facility, and a data archive available for use by scientists worldwide through the ARM Climate Research Facility—a scientific user facility. The ARM Climate Research Facility currently operates more than 300 instrument systems that provide ground-based observations of the atmospheric column. To keep ARM at the forefront of climate observations, the ARM infrastructure depends heavily on instrument scientists and engineers, known as Mentors. Mentors must have an excellent understanding of instrumentation theory and operation for their instrument areas and have comprehensive knowledge of critical scale-dependent atmospheric processes. They must also possess the technical and analytical skills to develop new data retrievals that provide innovative approaches for creating research-quality data sets. The ARM Facility seeks the best overall qualified candidate, or team when appropriate, that can fulfill Mentor requirements in a timely manner. The roles and responsibilities of the ARM Instrument Operations Manager are provided in Appendix A. The key role and responsibilities and detailed responsibilities of ARM Lead Mentors are provided in Appendix B and Appendix C, respectively.

47 OTHER INSTRUMENTATION↗

DOE OSTI2019

Description of the ARM Large-Scale Forcing Data from the Constrained Variational Analysis (VARANAL) Version 2

This technical report represents an update of the previous technical report written by Zhang et al., which described the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility constrained variational analysis (VARANAL) that is used to develop the large-scale forcing data for driving single-column models (SCMs), cloud-resolving models (CRMs), and large-eddy simulation models (LES). The VARANAL algorithm was originally developed by Zhang and Lin and Zhang et al. at Stony Brook University and was migrated to the Lawrence Livermore National Laboratory (LLNL) as the ARM operational objective analysis system in May 1999. Since then, the algorithm has been evolved with time along with the availability of new observations and techniques to meet various modeling needs. Major updates include: 1. The method used to develop multi-year continuous forcing data, 2. The incorporation of eddy correlation flux measurement system (ECOR) turbulent fluxes into the analysis, and 3. Improvements to the workflow (e.g., implementing part of the code into the ARM Data Integrator [ADI]) to increase efficiency. The ARM large-scale forcing data have been widely used for SCM/CRM/LES to understand and improve physical processes in models. Zhang et al. has provided a comprehensive review of the SCM concept, early efforts to derive forcing data for SCM studies, efforts of the ARM constrained variational analysis, and previous SCM studies using ARM cases. This technical report focuses on the constrained variational analysis algorithm and the introduction of the ARM VARANAL products. We also extended the VARANAL algorithm into a three-dimensional constrained variational analysis (3DCVA) and designed an ensemble framework to address the forcing uncertainty. The 3D large-scale forcing data are released as another datastream named “varanal3d”. Please refer to the ARM varanal3d technical report for more information.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2021

ARM Aerosol Measurement Science Group 2019 Strategic Planning Workshop Report

This report summarizes the results of a U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility workshop held in November 2019 to advance a science-based strategy for ARM’s aerosol measurement program. This was the second such workshop since the Aerosol Measurement Science Group (AMSG) was chartered in 2015 to enhance coordination of ARM observations of aerosols and atmospheric trace gases with the needs of ARM users. The results presented here reflect the AMSG’s focus in recent years on science-based strategies that will contribute to the increased use of ARM data to fulfill its mission of improving process representations and predictability in climate models. Sessions held during the workshop range from interfacing with models through aerosol sampling strategies to calibration protocols and data products. The strategies set forth here were also developed to be directly relevant to ARM’s updated Decadal Vision. The AMSG workshops have been designed to recommend actions that will enable ARM to evolve and continue to meet its mission. To that end, the AMSG will develop an actionable plan from the recommendations outlined here. Some are well defined and can reasonably be accomplished in the short term. Others are less definite or of a larger scope that calls for a longer-term implementation. Further discussion will be required to develop and prioritize actionable items related to such areas. Task teams comprising the appropriate expertise and perspective from the AMSG and other members of the community will be formed to achieve this outcome. Some particular topics are recognized as high priority, so plans are underway to develop task teams and to hold follow-on discussions to address them. Four areas currently being considered for short, focused discussion are 1) aerosol measurements on the North Slope of Alaska, 2) improving data usability for modeling, 3) strategies for advancing remote sensing, vertical profiling, and distributed measurements of aerosols, and 4) aerosol sampling strategies at existing ARM sites to provide intensive modes of operation to promote data usage for process and modeling studies.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2023

Science Plan for the Deployment of the Third ARM Mobile Facility to the Southeastern United States at the Bankhead National Forest, Alabama (AMF3 BNF)

In 2018, the U.S. Department of Energy (DOE) held a workshop for the Atmospheric Radiation Measurement (ARM) (Mather and Voyles 2013) user facility to discuss critical climate challenges and locations where key ARM Mobile Facility (AMF) observational assets could impact Earth system modeling (ESM). As an outcome, the southeast United States (SE U.S.) was identified as a high-priority region to target climate-process studies that promote a deeper understanding of the climate system and bolster ARM interactions with the community to drive ESM advancement. The DOE ARM user facility is a globally recognized leader in deploying and operating strategically located observation sites around the world for studying the properties of aerosols and clouds and their interaction with radiation, precipitation, and the Earth’s surface. In partnering with the DOE Atmospheric System Research (ASR) program, ARM solicited a multi-agency Site Science Team approach to provide input and close interaction with ARM management towards a successful SE U.S. deployment of the ARM third Mobile Facility (AMF3) (Miller et al. 2016). These efforts included identifying key locations, science drivers and instruments, and measurement strategies to address the wider climate-process needs and ESM improvement. Community input served a vital role in establishing, refining, and informing the relevant drivers and decisions regarding this AMF3 deployment. The team has identified Northern Alabama (N. AL) as regionally representative to unlock the key opportunities that will improve our understanding and model representation of aerosol, cloud, and land-surface processes and their couplings in the SE U.S. A defining aspect of the AMF3 deployment is its commitment to long-term (anticipated five-year) observations to mitigate potential seasonal-to-annual variability that often limits appropriate attribution of phenomena to local or larger-scale processes. The proposed location may leverage nearby surface networks and multi-agency and partner assets to enrich this multi-year deployment. One motivation is to understand the role of spatiotemporal variability (thermodynamic, land-surface) across aspects of the climate system, with our AMF3 team anticipating future demands on characterizing the relationships between local-to-regional cloud development and surface processes across a diverse patchwork of natural, managed, and urban landscapes as found throughout the N. AL regions. The main site targets an intact, representative, forested region – the Bankhead National Forest (BNF) – underscoring further team commitment to regionally important land-atmosphere two-way interactive studies “from the canopy to the clouds”, with enhanced tower instrumentation augmenting traditional ARM capabilities adjacent to this site. Multiple supplemental sites will also be distributed across this region, prioritizing added needs for biodiversity. Anticipated high-priority cloud science themes will target N. AL as a regional SE U.S. hotbed for high-impact weather, convective cloud onset, and shallow-to-deep cloud transitioning. Anticipated aerosol drivers will focus on chemical processes that control the evolution of organic aerosol, the seasonality and spatial distribution of water vapor and particle-phase water, and its role on aerosol optical properties. Anticipated land-atmosphere drivers consider the two-way feedbacks between surface influence on aerosols, clouds, and precipitation properties and the associated radiative impacts on plant physiology and canopy-scale fluxes. Emphasis will include the study of the impact of surface processes on aerosols via precursor emission, and on clouds via moisture flux and thermal development.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2017

Grand-design Spiral Arms in a Young Forming Circumstellar Disk

We study formation and long-term evolution of a circumstellar disk in a collapsing molecular cloud core using a resistive magnetohydrodynamic simulation. While the formed circumstellar disk is initially small, it grows as accretion continues, and its radius becomes as large as 200 au toward the end of the Class-I phase. A pair of grand-design spiral arms form due to gravitational instability in the disk, and they transfer angular momentum in the highly resistive disk. Although the spiral arms disappear in a few rotations as expected in a classical theory, new spiral arms form recurrently as the disk, soon becoming unstable again by gas accretion. Such recurrent spiral arms persist throughout the Class-0 and I phases. We then perform synthetic observations and compare our model with a recent high-resolution observation of a young stellar object Elias 2–27, whose circumstellar disk has grand-design spiral arms. We find good agreement between our theoretical model and the observation. Our model suggests that the grand-design spiral arms around Elias 2–27 are consistent with material arms formed by gravitational instability. If such spiral arms commonly exist in young circumstellar disks, it implies that young circumstellar disks are considerably massive and gravitational instability is the key process of angular momentum transport.

79 ASTRONOMY AND ASTROPHYSICS↗

NASA NTRS1990

Dual redundant arm system operational quality measures and their applications - Static measures

The authors present dual-arm system static operational quality measures which quantify the efficiency and capability of a dual-arm system in generating Cartesian velocities and static forces. First, they define and analyze the kinematic interactions between the two arms incurred by the various modes of dual-arm cooperation, such as transport, assembly, and grasping modes of cooperation, and specify the kinematic constraints imposed on individual arms in Cartesian space due to the kinematic interactions. Dual-arm static manipulability is presented. Finally, dual-arm operational quality is scaled by a task-oriented operational quality measure (TOQs) obtained by the comparison between the desired and actual static manipulabilities. TOQs is used in the optimization of dual-arm joint configurations. Simulation results are shown.

Lee, Sukhan↗

NASA NTRS1991

Dual-arm manipulators with adaptive control

The described and improved multi-arm invention of this application presents three strategies for adaptive control of cooperative multi-arm robots which coordinate control over a common load. In the position-position control strategy, the adaptive controllers ensure that the end-effector positions of both arms track desired trajectories in Cartesian space despite unknown time-varying interaction forces exerted through a load. In the position-hybrid control strategy, the adaptive controller of one arm controls end-effector motions in the free directions and applied forces in the constraint directions; while the adaptive controller of the other arm ensures that the end-effector tracks desired position trajectories. In the hybrid-hybrid control strategy, the adaptive controllers ensure that both end-effectors track reference position trajectories while simultaneously applying desired forces on the load. In all three control strategies, the cross-coupling effects between the arms are treated as disturbances which are compensated for by the adaptive controllers while following desired commands in a common frame of reference. The adaptive controllers do not require the complex mathematical model of the arm dynamics or any knowledge of the arm dynamic parameters or the load parameters such as mass and stiffness. Circuits in the adaptive feedback and feedforward controllers are varied by novel adaptation laws.

Seraji, Homayoun↗

NASA NTRS2004

Two-Armed, Mobile, Sensate Research Robot

The Anthropomorphic Robotic Testbed (ART) is an experimental prototype of a partly anthropomorphic, humanoid-size, mobile robot. The basic ART design concept provides for a combination of two-armed coordination, tactility, stereoscopic vision, mobility with navigation and avoidance of obstacles, and natural-language communication, so that the ART could emulate humans in many activities. The ART could be developed into a variety of highly capable robotic assistants for general or specific applications. There is especially great potential for the development of ART-based robots as substitutes for live-in health-care aides for home-bound persons who are aged, infirm, or physically handicapped; these robots could greatly reduce the cost of home health care and extend the term of independent living. The ART is a fully autonomous and untethered system. It includes a mobile base on which is mounted an extensible torso topped by a head, shoulders, and two arms. All subsystems of the ART are powered by a rechargeable, removable battery pack. The mobile base is a differentially- driven, nonholonomic vehicle capable of a speed >1 m/s and can handle a payload >100 kg. The base can be controlled manually, in forward/backward and/or simultaneous rotational motion, by use of a joystick. Alternatively, the motion of the base can be controlled autonomously by an onboard navigational computer. By retraction or extension of the torso, the head height of the ART can be adjusted from 5 ft (1.5 m) to 6 1/2 ft (2 m), so that the arms can reach either the floor or high shelves, or some ceilings. The arms are symmetrical. Each arm (including the wrist) has a total of six rotary axes like those of the human shoulder, elbow, and wrist joints. The arms are actuated by electric motors in combination with brakes and gas-spring assists on the shoulder and elbow joints. The arms are operated under closed-loop digital control. A receptacle for an end effector is mounted on the tip of the wrist and contains a force-and-torque sensor that provides feedback for force (compliance) control of the arm. The end effector could be a tool or a robot hand, depending on the application.

Engelberger, J. F.↗

NASA NTRS2016

An Overview of NASA's Asteroid Redirect Mission (ARM) Concept

The National Aeronautics and Space Administration (NASA) is developing the Asteroid Redirect Mission (ARM) as a capability demonstration for future human exploration, including use of high-power solar electric propulsion, which allows for the efficient movement of large masses through deep space. The ARM will also demonstrate the capability to conduct proximity operations with natural space objects and crewed operations beyond the security of quick Earth return. The Asteroid Redirect Robotic Mission (ARRM), currently in formulation, will visit a large near-Earth asteroid (NEA), collect a multi-ton boulder from its surface, conduct a demonstration of a slow push planetary defense technique, and redirect the multi-ton boulder into a stable orbit around the Moon. Once returned to cislunar space in the mid-2020s, astronauts aboard an Orion spacecraft will dock with the robotic vehicle to explore the boulder and return samples to Earth. The ARM is part of NASA's plan to advance technologies, capabilities, and spaceflight experience needed for a human mission to the Martian system in the 2030s. The ARM and subsequent availability of the asteroidal material in cis-lunar space, provide significant opportunities to advance our knowledge of small bodies in the synergistic areas of science, planetary defense, and in-situ resource utilization (ISRU). NASA established the Formulation Assessment and Support Team (FAST), comprised of scientists, engineers, and technologists, which supported ARRM mission requirements formulation, answered specific questions concerning potential target asteroid physical properties, and produced a publically available report. The ARM Investigation Team is being organized to support ARM implementation and execution. NASA is also open to collaboration with its international partners and welcomes further discussions. An overview of the ARM robotic and crewed segments, including mission requirements, NEA targets, and mission operations, and a discussion of potential opportunities for participation with the ARM will be provided.

Abell, P. A.↗