Search NASA⌕ Search

SEARCH · Search NASA

Results for “SENSORY FEEDBACK”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Sensorimotor Predictors: Examining the Relationship Between Measures of Post-Landing Sensorimotor Functional Task Performance

Spaceflight drives adaptive changes in healthy individuals appropriate for sensorimotor function in a microgravity environment. These changes are maladaptive for return to Earth's gravity. The inter-individual variability of sensorimotor decrements is striking, although poorly understood. The goal of this study is to identify a set of behavioral, neuroimaging and genetic measures that can be used to predict early post-flight performance on sensorimotor functional tasks. To date, we have recruited fifteen astronauts who returned from the International Space Station on Soyuz and participated in sensorimotor field tests and/or posturography within one day following long-duration spaceflight. We are specifically utilizing a combination of three quantitative post-flight functional task outcomes(relative to pre-flight baselines): tandem walk, recovery from fall and dynamic posturography, along with a subjective self-rating of post-flight decrements and recovery. The recovery from fall is performed with eyes open on a stable support, allowing the use of vestibular, visual and proprioceptive feedback for task performance. In contrast, the dynamic posturography measures are performed with eyes closed on asway-referenced unstable support, requiring reliance on vestibular feedback for task performance. Tandem walk is performed on a stable surface with eyes open and eyes closed. Fourteen of the 15 subjects performed the field tests. These were nominally performed during three timepoints on the first post flight day, while posturography was performed only once during the third time point after direct return to JSC. More than 20% were unable to complete the initial field testing in the medical tent, while all participants completed testing during the third time point at JSC. As expected, there was considerable variability among all performance outcome measures, with more variability post-flight relative to preflight. Given the variability in all post-flight outcomes, we have been examining the relationships in performance across tasks. While there is a strong association with in tests obtained at different landing daytime points, our preliminary findings suggest that by R+24 hrs performance on one post-flight test does not necessarily correlate with performance on other post-flight tests. This underscores the importance of a comprehensive post-flight test battery including different types of tasks with varying sensory feedback. We expect that further examining specific behavioral, neuroimaging and genetic sensorimotor biomarkers with post-flight functional task performance will improve both our understanding of the individual variability and our strategy to optimize sensorimotor countermeasures.

Yiri De Dios↗
NASA NTRS1974

Neurological applications of man-machine systems analysis

Quantitative descriptions of human control properties are formulated that take into account the dynamics of muscle actuation units, neuromuscular sensor units, and sensory feedback mechanics. Detailed dynamic measurements on neurologically disordered patients are correlated with clinical manifestations of various neurological syndromes to quantify operator behavior.

Mcruer, D. T.↗
NASA NTRS1975

Control automation in undersea manipulation systems

The requirements for the successful use of automated manipulation in an undersea environment are discussed, and initial specifications for systems which share control between a human operator and an autonomous control element are established. Areas of concern include: (1) objectives of automation; (2) characteristics of the underwater task; (3) hierarchy of control algorithms; (4) man/machine interface; (5) sensory feedback; and (6) general system organization. Special emphasis is placed on the solutions to the problem of controlling an undersea manipulator which is capable of performing certain automatic functions and implementing these solutions using current technology. Current capabilities for control automation are summarized.

Freedy, A.↗
NASA NTRS1975

System integration of pattern recognition, adaptive aided, upper limb prostheses

The requirements for successful integration of a computer aided control system for multi degree of freedom artificial arms are discussed. Specifications are established for a system which shares control between a human amputee and an automatic control subsystem. The approach integrates the following subsystems: (1) myoelectric pattern recognition, (2) adaptive computer aiding; (3) local reflex control; (4) prosthetic sensory feedback; and (5) externally energized arm with the functions of prehension, wrist rotation, elbow extension and flexion and humeral rotation.

Lyman, J.↗
NASA NTRS1981

Robots and manipulators

Robots are defined and described for various applications. The key feature of robots is programmability, which allows teleoperation, repair work in hazardous situations, and unsupervised operation in industrial functions. Two types of robots now exist: special purpose, with equipment for a specific task; and general purpose, which include nonservo-controlled robots, servo-controlled robots, and sensory control robots. Sensory robots are the most sophisticated, and are equipped with both internal control sensors and external sensors such as TV cameras, pressure detectors, laser range finders, etc. Sensory feedback to a central computer enables the robots to make appropriate modifications to the control program to adapt to new situations. Pattern recognition and scans for size are features of the TV sensors, and programs to develop a universal effector (hand) are outlined. Finally, robot programming in terms of manual, walkthrough, and textual methods are described, and the potential uses of robots for space and undersea construction and repair are discussed.

Heer, E.↗
NASA NTRS1984

Three-Level Control of Manipulators

Concept for control of remote manipulators based on three-level hierarchy allows complex tasks performed in real time. Developed for interactive human/control with sensory feedback.

Zawacki, R. L.↗
NASA NTRS1984

An intelligent robotics control scheme

The problem of robot control is viewed at the level of communicating high-level commands produced by intelligent algorithms to the actuator/sensor controllers. Four topics are considered in the design of an integrated control and communications scheme for an intelligent robotic system: the use of abstraction spaces, hierarchical versus heterarchical control, distributed processing, and the interleaving of the steps of plan creation and plan execution. A scheme is presented for an n-level distributed hierarchical/heterarchical control system that effectively interleaves intelligent planning, execution, and sensory feedback. A three-level version of this scheme has been successfully implemented in the Intelligent Systems Research Lab at NASA Langley Research Center. This implementation forms the control structure for DAISIE (Distributed Artificially Intelligent System for Interacting with the Environment), a testbed system integrating AI software with robotics hardware.

Orlando, N. E.↗
NASA NTRS1985

Telepresence work system concepts

Telepresence has been used in the context of the ultimate in remote manipulation where the operator is provided with the sensory feedback and control to perform highly dexterous tasks. The concept of a Telepresence Work Station (TWS) for operation in space is described. System requirements, concepts, and a development approach are discussed. The TWS has the potential for application on the Space Shuttle, on the Orbit Maneuver Vehicle, on an Orbit Transfer Vehicle, and on the Space Station. The TWS function is to perform satellite servicing tasks and construction and assembly operations in the buildup of large spacecraft. The basic concept is a pair of dexterous arms controlled from a remote station by an operation with feedback. It may be evolved through levels of supervisory control to a smart adaptive robotic system.

Jenkins, L. M.↗
NASA NTRS1986

Evaluating space station applications of automation and robotics technologies from a human productivity point of view

The role that automation, robotics, and artificial intelligence will play in Space Station operations is now beginning to take shape. Although there is only limited data on the precise nature of the payoffs that these technologies are likely to afford there is a general consensus that, at a minimum, the following benefits will be realized: increased responsiveness to innovation, lower operating costs, and reduction of exposure to hazards. Nevertheless, the question arises as to how much automation can be justified with the technical and economic constraints of the program? The purpose of this paper is to present a methodology which can be used to evaluate and rank different approaches to automating the functions and tasks planned for the Space Station. Special attention is given to the impact of advanced automation on human productivity. The methodology employed is based on the Analytic Hierarchy Process. This permits the introduction of individual judgements to resolve the confict that normally arises when incomparable criteria underly the selection process. Because of the large number of factors involved in the model, the overall problem is decomposed into four subproblems individually focusing on human productivity, economics, design, and operations, respectively. The results from each are then combined to yield the final rankings. To demonstrate the methodology, an example is developed based on the selection of an on-orbit assembly system. Five alternatives for performing this task are identified, ranging from an astronaut working in space, to a dexterous manipulator with sensory feedback. Computational results are presented along with their implications. A final parametric analysis shows that the outcome is locally insensitive to all but complete reversals in preference.

Bard, J. F.↗
NASA NTRS1988

Precise computer controlled positioning of robot end effectors using force sensors

A thorough study of combined position/force control using sensory feedback for a one-dimensional manipulator model, which may count for the spacecraft docking problem or be extended to the multi-joint robot manipulator problem, was performed. The additional degree of freedom introduced by the compliant force sensor is included in the system dynamics in the design of precise position control. State feedback based on the pole placement method and with integral control is used to design the position controller. A simple constant gain force controller is used as an example to illustrate the dependence of the stability and steady-state accuracy of the overall position/force control upon the design of the inner position controller. Supportive simulation results are also provided.

Shieh, L. S.↗
NASA NTRS1988

End-effector - joint conjugates for robotic assembly of large truss structures in space: A second generation

Current designs, a first generation intended for robotic assembly, have given priority to the ease and certainty of the assembly process under less than ideal conditions with a minimum of sensory feedback. As a consequence they are either heavy or expensive and all exhibit a relatively low packaging density. Low packaging density is caused by extensive scars applied to the node, increasing its envelope diameter by as much as 150 percent. Strut envelopes are violated to a lessor extent with diameters increased by 25 percent or more. This smaller percentage is still a significant problem owing to a much higher fraction of the packaged volume represented by struts. As structures in space become larger, packaging density becomes an important consideration. The objective is to develop end-effector-joint conjugates that do not violate the envelopes of a 2.5 inch diameter node or a 1.0 inch diameter strut.

Brewer, W. V.↗
NASA NTRS1987

Object apprehension using vision and touch

Researchers define object apprehension as the determination of the properties of an object and the relationships among these properties. They contrast this with recognition, which goes a step further to attach a label to the object as a whole. Apprehension is fundamental to manipulation. This is true whether the manipulation is being carried out by an autonomous robot or is the result of teleoperation involving sensory feedback. Researchers present an apprehension paradigm using both vision and touch. In this model, they define a representation for object apprehension in terms of a set of primitives and features, along with their relationships. This representation is the mechanism by which the data from the two modalities are combined. It is also the mechanism which drives the apprehension process.

Bajcsy, R.↗
NASA NTRS1989

Robotic control of the seven-degree-of-freedom NASA laboratory telerobotic manipulator

A computationally efficient robotic control scheme for the NASA Laboratory Telerobotic Manipulator (LTM) is presented. This scheme utilizes the redundancy of the seven-degree-of-freedom LTM to avoid joint limits and singularities. An analysis to determine singular configurations is presented. Performance criteria are determined based on the joint limits and singularity analysis. The control scheme is developed in the framework of resolved rate control using the gradient projection method, and it does not require the generalized inverse of the Jacobian. An efficient formulation for determining the joint velocities of the LTM is obtained. This control scheme is well suited for real-time implementation, which is essential if the end-effector trajectory is continuously modified based on sensory feedback. Implementation of this scheme on a Motorola 68020 VME bus-based controller of the LTM is in progress. Simulation results demonstrating the redundancy utilization in the robotic mode are presented.

Dubey, R. V.↗
NASA NTRS1991

Real-time, interactive, visually updated simulator system for telepresence

Time delays and limited sensory feedback of remote telerobotic systems tend to disorient teleoperators and dramatically decrease the operator's performance. To remove the effects of time delays, key components were designed and developed of a prototype forward simulation subsystem, the Global-Local Environment Telerobotic Simulator (GLETS) that buffers the operator from the remote task. GLETS totally immerses an operator in a real-time, interactive, simulated, visually updated artificial environment of the remote telerobotic site. Using GLETS, the operator will, in effect, enter into a telerobotic virtual reality and can easily form a gestalt of the virtual 'local site' that matches the operator's normal interactions with the remote site. In addition to use in space based telerobotics, GLETS, due to its extendable architecture, can also be used in other teleoperational environments such as toxic material handling, construction, and undersea exploration.

Schebor, Frederick S.↗
NASA NTRS1991

Outline for a theory of intelligence

Intelligence is defined as that which produces successful behavior. Intelligence is assumed to result from natural selection. A model is proposed that integrates knowledge from research in both natural and artificial systems. The model consists of a hierarchical system architecture wherein: (1) control bandwidth decreases about an order of magnitude at each higher level, (2) perceptual resolution of spatial and temporal patterns contracts about an order-of-magnitude at each higher level, (3) goals expand in scope and planning horizons expand in space and time about an order-of-magnitude at each higher level, and (4) models of the world and memories of events expand their range in space and time by about an order-of-magnitude at each higher level. At each level, functional modules perform behavior generation (task decomposition planning and execution), world modeling, sensory processing, and value judgment. Sensory feedback control loops are closed at every level.

Albus, James S.↗
NASA NTRS1991

Human factors considerations for training astronauts to function effectively in multiple environments

This paper reviews some of the basic issues involved in training individuals to function appropriately under the several conditions that comprise the aerospace environment. The topic of transfer of training is examined in some detail, and the use of high-fidelity simulators in various training programs is discussed. Both current and classical techniques used to train astronauts are noted, and some relatively new and innovative training techniques and methods are described. Particularly, the paper discusses an important aspect of functioning appropriately in a given environment that is based on how well the operator calibrates his motor activity for that specific environment. The role of motor-sensory feedback for the acquisition of motor skills is discussed in the context of training.

Cohen, Malcolm M.↗
NASA NTRS1994

ISMCR 1994: Topical Workshop on Virtual Reality. Proceedings of the Fourth International Symposium on Measurement and Control in Robotics

This symposium on measurement and control in robotics included sessions on: (1) rendering, including tactile perception and applied virtual reality; (2) applications in simulated medical procedures and telerobotics; (3) tracking sensors in a virtual environment; (4) displays for virtual reality applications; (5) sensory feedback including a virtual environment application with partial gravity simulation; and (6) applications in education, entertainment, technical writing, and animation.

Source record↗