26 research outputs found
Telerobot operator control station requirements
The operator control station of a telerobot system has unique functional and human factors requirements. It has to satisfy the needs of a truly interactive and user-friendly complex system, a telerobot system being a hybrid between a teleoperated and an autonomous system. These functional, hardware and software requirements are discussed, with explicit reference to the design objectives and constraints of the JPL/NASA Telerobot Demonstrator System
A space servicing telerobotics technology demonstration
Supervised telerobotic controls provide the key to successful remote servicing, as demonstrated in the telerobot testbed of the jet propulsion laboratory. Such advanced techniques and systems are specially applicable to ground-remote operations for servicing tasks, which are to be performed remotely in space and to be operated under human supervision from the ground. Laboratory demonstrations have successfully proven the utility of such techniques and systems. Instrumental to the success of supervised robotic operations are the techniques called object designate and relative target. In addition, a technique called universal camera calibration was also applied in the telerobot testbed. Generalized compliant control techniques were used in the robotic removal and insertion operations. These techniques were proven successful in task situations where preprogrammed automation cannot be adequately exercised due to errors, changes, or omission in the worksite data base
Flight telerobot mechanism design: Problems and challenges
Problems and challenges of designing flight telerobot mechanisms are discussed. Specific experiences are drawn from the following system developments: (1) the Force Reflecting Hand Controller, (2) the Smart End Effector, (3) the force-torque sensor, and a generic multi-degrees-of-freedom manipulator
Mission operations data analysis tools for Mars Observer guidance and control
Mission operations for the Mars Observer (MO) Project at the Jet Propulsion Laboratory were supported by a variety of ground data processing software and analysis tools. Some of these tools were generic to multimission spacecraft mission operations, some were specific to the MO spacecraft, and others were custom tailored to the operation and control of the Attitude and Articulation Control Subsystem (AACS). The focus of this paper is on the data analysis tools for the AACS. Four different categories of analysis tools are presented; with details offered for specific tools. Valuable experience was gained from the use of these tools and through their development. These tools formed the backbone and enhanced the efficiency of the AACS Unit in the Mission Operations Spacecraft Team. These same tools, and extensions thereof, have been adopted by the Galileo mission operations, and are being designed into Cassini and other future spacecraft mission operations
Process and methodology of developing Cassini G and C Telemetry Dictionary
While the Cassini spacecraft telemetry design had taken on the new approach of 'packetized telemetry', the AACS (Attitude and Articulation Subsystem) had further extended into the design of 'mini-packets' in its telemetry system. Such telemetry packet and mini-packet design produced the AACS Telemetry Dictionary; iterations of the latter in turn provided changes to the former. The ultimate goals were to achieve maximum telemetry packing density, optimize the 'freshness' of more time-critical data, and to effect flexibility, i.e., multiple AACS data collection schemes, without needing to change the overall spacecraft telemetry mode. This paper describes such a systematic process and methodology, evidenced by various design products related to, or as part of, the AACS Telemetry Dictionary
The JPL telerobot operator control station. Part 2: Software
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
The JPL telerobot operator control station. Part 1: Hardware
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 hardware design, system architecture, and its integration and interface with the rest of the Telerobot Demonstrator System are discussed
An atomistic quantum transport solver with dephasing for field-effect transistors
Extended Huckel theory (EHT) along with NEGF (Non-equilibrium Green's
function formalism) has been used for modeling coherent transport through
molecules. Incorporating dephasing has been proposed to theoretically reproduce
experimental characteristics for such devices. These elastic and inelastic
dephasing effects are expected to be important in quantum devices with the
feature size around 10nm, and hence an efficient and versatile solver is
needed. This model should have flexibility to be applied to a wide range of
nano-scale devices, along with 3D electrostatics, for arbitrary shaped contacts
and surface roughness. We report one such EHT-NEGF solver with dephasing by
self-consistent Born approximation (SCBA). 3D electrostatics is included using
a finite-element scheme. The model is applied to a single wall carbon nanotube
(CNT) cross-bar structure with a C60 molecule as the active channel. Without
dephasing, a negative differential resistance (NDR) peak appears when the C60
lowest unoccupied molecular orbital level crosses a van Hove singularity in the
1D density of states of the metallic CNTs acting as contacts. This NDR
diminishes with increasing dephasing in the channel as expected.Comment: to appear in Journal of Computational Electronic
How Emotion Strengthens the Recollective Experience: A Time-Dependent Hippocampal Process
Emotion significantly strengthens the subjective recollective experience even when objective accuracy of the memory is not improved. Here, we examine if this modulation is related to the effect of emotion on hippocampal-dependent memory consolidation. Two critical predictions follow from this hypothesis. First, since consolidation is assumed to take time, the enhancement in the recollective experience for emotional compared to neutral memories should become more apparent following a delay. Second, if the emotion advantage is critically dependent on the hippocampus, then the effects should be reduced in amnesic patients with hippocampal damage. To test these predictions we examined the recollective experience for emotional and neutral photos at two retention intervals (Experiment 1), and in amnesics and controls (Experiment 2). Emotional memories were associated with an enhancement in the recollective experience that was greatest after a delay, whereas familiarity was not influenced by emotion. In amnesics with hippocampal damage the emotion effect on recollective experience was reduced. Surprisingly, however, these patients still showed a general memory advantage for emotional compared to neutral items, but this effect was manifest primarily as a facilitation of familiarity. The results support the consolidation hypothesis of recollective experience, but suggest that the effects of emotion on episodic memory are not exclusively hippocampally mediated. Rather, emotion may enhance recognition by facilitating familiarity when recollection is impaired due to hippocampal damage
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure