84,217 research outputs found

    Exoskeleton master controller with force-reflecting telepresence

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    A thorough understanding of the requirements for successful master-slave robotic systems is becoming increasingly desirable. Such systems can aid in the accomplishment of tasks that are hazardous or inaccessible to humans. Although a history of use has proven master-slave systems to be viable, system requirements and the impact of specifications on the human factors side of system performance are not well known. In support of the next phase of teleoperation research being conducted at the Armstrong Research Laboratory, a force-reflecting, seven degree of freedom exoskeleton for master-slave teleoperation has been concepted, and is presently being developed. The exoskeleton has a unique kinematic structure that complements the structure of the human arm. It provides a natural means for teleoperating a dexterous, possibly redundant manipulator. It allows ease of use without operator fatigue and faithfully follows human arm and wrist motions. Reflected forces and moments are remotely transmitted to the operator hand grip using a cable transmission scheme. This paper presents the exoskeleton concept and development results to date. Conceptual design, hardware, algorithms, computer architecture, and software are covered

    Systematic development of courseware systems

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    Various difficulties have been reported in relation to the development of courseware systems. A central problem is to address the needs of not only the learner, but also instructor, developer, and other stakeholders, and to integrate these different needs. Another problem area is courseware architectures, to which much work has been dedicated recently. We present a systematic approach to courseware development – a methodology for courseware engineering – that addresses these problems. This methodology is rooted in the educational domain and is based on methods for software development in this context. We illustrate how this methodology can improve the quality of courseware systems and the development process

    The laboratory telerobotic manipulator program

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    New opportunities for the application of telerobotic systems to enhance human intelligence and dexterity in the hazardous environment of space are presented by the NASA Space Station Program. Because of the need for significant increases in extravehicular activity and the potential increase in hazards associated with space programs, emphasis is being heightened on telerobotic systems research and development. The Laboratory Telerobotic Manipulator (LTM) program is performed to develop and demonstrate ground-based telerobotic manipulator system hardware for research and demonstrations aimed at future NASA applications. The LTM incorporates traction drives, modularity, redundant kinematics, and state-of-the-art hierarchical control techniques to form a basis for merging the diverse technological domains of robust, high-dexterity teleoperations and autonomous robotic operation into common hardware to further NASA's research

    Domain-oriented architecture design for production control software

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    this paper, we present domain-oriented architectural design heuristics for production control software. Our approach is based upon the following premisses. First, software design, like all other forms of design, consists of the reduction of uncertainty about a final product by making design decisions. These decisions should as much as possible be based upon information that is certain, either because they represent laws of nature or because they represent previously made design decisions. An import class of information concerns the domain of the software. The domain of control software is the part of the world monitored and controlled by the software; it is the larger system into which the software is embedded. The software engineer should exploit system-level domain knowledge in order to make software design decisions. Second, in the case of production control software, using system-level knowledge is not only justified, it is also imposed on the software engineer by the necessity to cooperate with hardware engineers. These represent their designs by means of Process and Instrumentation Diagrams (PIDs) and Input-Output (IO) lists. They do not want to spend time, nor do they see the need, to duplicate the information represented by these diagrams by means of diagrams from software engineering methods. Such a duplication would be an occasion to introduce errors of omission (information lost during the translation process) or commission (misinterpretation, misguided but invisible design decisions made during the translation) anyway. We think it is up to the software engineer to adapt his or her notations to those of the system engineers he or she must work with. Third, work in patterns and software architectures started from the programminglanguage level and is now moving..

    The Flight Telerobotic Servicer (FTS) NASA's first operational robotic system

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    NASA has completed the preliminary definition phase of the Flight Telerobotic Servicer (FTS) and is now preparing to begin the detailed design and fabrication phase. The FTS will be designed and built by Martin Marietta Astronautics Group in Denver, CO, for the Goddard Space Flight Center, in support of the Space Station Freedom Program. The design concepts for the FTS are discussed, as well as operational scenarios for the assembly, maintenance, servicing and inspection tasks which are being considered for the FTS. The upcoming Development Test Flight (DTF-1) is the first of two shuttle test flights to test FTS operations in the environment of space and to demonstrate the FTS capabilities in performing tasks for Space Station Freedom. Operational planning for DTF-1 is discussed as well as development plans for the operational support of the FTS on the space station

    Massive MIMO is a Reality -- What is Next? Five Promising Research Directions for Antenna Arrays

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    Massive MIMO (multiple-input multiple-output) is no longer a "wild" or "promising" concept for future cellular networks - in 2018 it became a reality. Base stations (BSs) with 64 fully digital transceiver chains were commercially deployed in several countries, the key ingredients of Massive MIMO have made it into the 5G standard, the signal processing methods required to achieve unprecedented spectral efficiency have been developed, and the limitation due to pilot contamination has been resolved. Even the development of fully digital Massive MIMO arrays for mmWave frequencies - once viewed prohibitively complicated and costly - is well underway. In a few years, Massive MIMO with fully digital transceivers will be a mainstream feature at both sub-6 GHz and mmWave frequencies. In this paper, we explain how the first chapter of the Massive MIMO research saga has come to an end, while the story has just begun. The coming wide-scale deployment of BSs with massive antenna arrays opens the door to a brand new world where spatial processing capabilities are omnipresent. In addition to mobile broadband services, the antennas can be used for other communication applications, such as low-power machine-type or ultra-reliable communications, as well as non-communication applications such as radar, sensing and positioning. We outline five new Massive MIMO related research directions: Extremely large aperture arrays, Holographic Massive MIMO, Six-dimensional positioning, Large-scale MIMO radar, and Intelligent Massive MIMO.Comment: 20 pages, 9 figures, submitted to Digital Signal Processin

    Managing computer-controlled operations

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    A detailed discussion of Launch Processing System Ground Software Production is presented to establish the interrelationships of firing room resource utilization, configuration control, system build operations, and Shuttle data bank management. The production of a test configuration identifier is traced from requirement generation to program development. The challenge of the operational era is to implement fully automated utilities to interface with a resident system build requirements document to eliminate all manual intervention in the system build operations. Automatic update/processing of Shuttle data tapes will enhance operations during multi-flow processing

    The JPL telerobot operator control station. Part 2: Software

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    The Operator Control Station of the Jet Propulsion Laboratory (JPL)/NASA Telerobot Demonstrator System provides the man-machine interface between the operator and the system. It provides all the hardware and software for accepting human input for the direct and indirect (supervised) manipulation of the robot arms and tools for task execution. Hardware and software are also provided for the display and feedback of information and control data for the operator's consumption and interaction with the task being executed. The software design of the operator control system is discussed
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