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At least 145 records · Page 8

Survey of Hand Controllers for Teleoperation

Report surveys handgrip designs, control-input devices, and control strategies. 83-page report presents comprehensive survey of hand-controller technology in three major categories: handgrip design, control-input devices, and control strategies. Approach taken in review to identify and describe existing handgrips, control-input devices and control strategies, and new components and techniques that become elements of advanced hand controllers to satisfy increasing performance requirements for teleoperation in future.

Brooks, T. L.

Robot Hand Grips Cylinders Securely

Jaws and linkage accommodate various sizes. Robot hand includes two pairs of parallel jaws that grasp rods, pipes, tubes, struts, and other long, heavy cylindrical objects. Hand features compact rotary drive and butterfly configuration simplifying approach and gripping maneuvers of robot. Parallelogram linkages maintain alignment of each jaw with other jaws. One bar of each linkage connected to one of two concentric, counterrotating shafts; rotation of shafts moves jaws in each pair toward or away from each other to grasp or release workpiece. Each jaw includes rigid gripping pad lined with rubber to give firm grip and to prevent damage to workpiece. Inner cylindrical surface (corner) of each jaw tapers off to flat sides. Enables jaw to grasp workpieces with diameters larger than or equal to twice the corner radius.

Parma, George F.

Robot Hand Would Adapt To Contours

Conceptual device uses hydraulic pressure to activate fingers. Projections on opposing fingers of proposed robot hand automatically conform to contours of object on contact. Pistons connected to common reservoir provide gentle, firm grip. Fingers communicate with each other via hydraulic pressure, without elaborate control system. Pistons move in and out, and tips slope to match contour of object. Their action tends to center object on finger. Hand used to grasp objects of various shapes and sizes. Conforming process passive; pressure of object on one or several pad elements forces other pad elements to touch it. Would not use elaborate mechanisms involving motors, cams, and cables.

Collins, Earl R., Jr.

Development of a multipurpose hand controller for JEMRMS

A prototype multipurpose hand controller for the JEMRMS (Japanese Experiment Module Remote Manipulator System) was developed. The hand controller (H/C) is an orthogonal type, with 6 degrees of freedom (DOF) and small size. The orthogonal type H/C is very simple for coordinate transformations and can easily control any type of manipulators. In fact, the JEMRMS is planned to have two manipulators controlled by a common H/C at this stage. The H/C was able to be used as a rate control joystick and a force reflection master arm, using an experimental 6 DOF manipulator. Good maneuverability was confirmed in the verification test. The orthogonal type H/C is suitable for use as a common H/C for the two manipulators of the JEMRMS.

Matsuhira, Nobuto

Redundant sensorized arm+hand system for space telerobotized manipulation

An integrated system, composed of an arm, a wrist, and a mechanical multifingered hand is treated. The hand is on development for possible application in telemanipulation, and is realized in separate parts. The redundancy of the degrees of freedom of the system, the sensors, the application of logical rules, and the supervision of teleoperators may be applied in order to have an optimum of reliability of the system in space telemanipulations.

Rovetta, Alberto

Teleoperation experiments with a Utah/MIT hand and a VPL DataGlove

A teleoperation system capable of controlling a Utah/MIT Dextrous Hand using a VPL DataGlove as a master is presented. Additionally the system is capable of running the dextrous hand in robotic (autonomous) mode as new programs are developed. The software and hardware architecture used is presented and the experiments performed are described. The communication and calibration issues involved are analyzed and applications to the analysis and development of automated dextrous manipulations are investigated.

Clark, D.

The effect of pressure suit gloves on hand performance

The effects of pressure gloves on human hand capabilities is a major concern in the performance of extravehicular activity (EVA) for space maintenance and construction missions. The effects of EVA gloves on six hand performance domains was investigated in this NASA sponsored research. They were range of motion, strength, tactile perception, dexterity, fatigue, and comfort. All tests were designed to be performed in a glove box using the barehand as well as the glove at 0 and 4.3 pressure differentials. Ten subjects participated in the test in a repeated measures design. The results of the experiments are summarized in this paper.

O'Hara, John M.

Neural-Network Control Of Prosthetic And Robotic Hands

Electronic neural networks proposed for use in controlling robotic and prosthetic hands and exoskeletal or glovelike electromechanical devices aiding intact but nonfunctional hands. Specific to patient, who activates grasping motion by voice command, by mechanical switch, or by myoelectric impulse. Patient retains higher-level control, while lower-level control provided by neural network analogous to that of miniature brain. During training, patient teaches miniature brain to perform specialized, anthropomorphic movements unique to himself or herself.

Buckley, Theresa M.

Control framework for hand-arm coordination

Coordination of multiple manipulators requires cooperation at several levels in the control hierarchy. A distributed processing environment with no hardware dependencies except at the motor servo level would provide a flexible architecture for coordination. A system on these lines is being built to control an articulated hand and an arm. The four levels of control envisaged include a task decomposition level, a planning level, a scheduling level, and a server level. The hand will carry both force and tactile sensors, feedback from these are used to provide adaptive control in grasping tasks. The processing of the sensory information is performed by independent processes, with analyzed information being sent to the relevant layer of the system. The manipulators are also controlled by individual processes. All process can open communications with an active process sending commands or data, or receiving them. The scope of the system and the current setup are described along with future lines of development.

Agrawal, Sanjay

A feasibility study of hand kinematics for EVA analysis using magnetic resonance imaging

A new method of analyzing the kinematics of joint motion is developed. Magnetic Resonance Imaging (MRI) offers several distinct advantages. Past methods of studying anatomic joint motion have usually centered on four approaches. These methods are x-ray projection, goniometric linkage analysis, sonic digitization, and landmark measurement of photogrammetry. Of these four, only x-ray is applicable for in vivo studies. The remaining three methods utilize other types of projections of inter-joint measurements, which can cause various types of error. MRI offers accuracy in measurement due to its tomographic nature (as opposed to projection) without the problems associated with x-ray dosage. Once the data acquisition of MR images was complete, the images were processed using a 3D volume rendering workstation. The metacarpalphalangeal (MCP) joint of the left index finger was selected and reconstructed into a three-dimensional graphic display. From the reconstructed volumetric images, measurements of the angles of movement of the applicable bones were obtained and processed by analyzing the screw motion of the MCP joint. Landmark positions were chosen at distinctive locations of the joint at fixed image threshold intensity levels to ensure repeatability. The primarily two dimensional planar motion of this joint was then studied using a method of constructing coordinate systems using three (or more) points. A transformation matrix based on a world coordinate system described the location and orientation of a local target coordinate system. Future research involving volume rendering of MRI data focusing on the internal kinematics of the hand's individual ligaments, cartilage, tendons, etc. will follow. Its findings will show the applicability of MRI to joint kinematics for gaining further knowledge of the hand-glove (power assisted) design for extravehicular activity (EVA).

Dickenson, Rueben D.

Ground Robotic Hand Applications for the Space Program study (GRASP)

This document reports on a NASA-STDP effort to address research interests of the NASA Kennedy Space Center (KSC) through a study entitled, Ground Robotic-Hand Applications for the Space Program (GRASP). The primary objective of the GRASP study was to identify beneficial applications of specialized end-effectors and robotic hand devices for automating any ground operations which are performed at the Kennedy Space Center. Thus, operations for expendable vehicles, the Space Shuttle and its components, and all payloads were included in the study. Typical benefits of automating operations, or augmenting human operators performing physical tasks, include: reduced costs; enhanced safety and reliability; and reduced processing turnaround time.

Grissom, William A.

Electronic, Hand-Held, Wireless Text-And-Graphics Viewer

Proposed electronic, hand-held, wireless viewer presents written material to reader in way that closely resembles that of paper reading material. Viewer presents text and graphics like those normally found in books, newspapers, and magazines. Its hand-held and wireless features enable it to be used in positions and areas where books and magazines are normally used. Device consists primarily of two parts: the receiver/information store and viewing screen.

Palumbo, Daniel L.

Conceptual design of an astronaut hand anthropometry device

In a microgravity environment, fluid equalizes throughout the body, causing the upper body to swell. This causes the hands to swell which can cause problems for astronauts trying to do work in pressurized EVA (extravehicular activity) gloves. To better design these gloves, accurate measurements of the astronauts swollen hands are needed. Five concepts were developed in this report from an original field of 972 possible concepts. These five concepts were based on mold impression, ultrasound, laser topography, white light photography, and video imaging. From a decision matrix based on nine weighted criteria, the video imaging technique was found to be the best design to pursue.

Mcmahan, Robert

Refinement for fault-tolerance: An aircraft hand-off protocol

Part of the Advanced Automation System (AAS) for air-traffic control is a protocol to permit flight hand-off from one air-traffic controller to another. The protocol must be fault-tolerant and, therefore, is subtle -- an ideal candidate for the application of formal methods. This paper describes a formal method for deriving fault-tolerant protocols that is based on refinement and proof outlines. The AAS hand-off protocol was actually derived using this method; that derivation is given.

Marzullo, Keith

Environmentally compatible hand wipe cleaning solvents

Several solvents of environmental concern have previously been used for hand wipe cleaning of SRB surfaces, including 1,1,1-trichloroethane, perchloroethylene, toluene, xylene, and MEK. USBI determined the major types of surfaces involved, and qualification requirements of replacement cleaning agents. Nineteen environmentally compatible candidates were tested on 33 material substrates with 26 types of potential surface contaminants, involving over 7,000 individual evaluations. In addition to the cleaning performance evaluation, bonding, compatibility, and corrosion tests were conducted. Results showed that one cleaner was not optimum for all surfaces. In most instances, some of the candidates cleaned better than the 1,1,1-trichloroethane baseline control. Aqueous cleaners generally cleaned better, and were more compatible with nonmetallic materials, such as paints, plastics, and elastomers. Organic base cleaners were better on metal surfaces. Five cleaners have been qualified and are now being implemented in SRB hand wipe cleaning operations.

Clayton, Catherine P.

Initial Usability Testing of a Hand-Held Electronic Logbook Prototype for the Human Research Facility

The Apple(R) Newton(TM) MessagePad 110 was flown aboard the KC-135 reduced gravity aircraft for microgravity usability testing. The Newton served as the initial hand-held electronic logbook prototype for the International Space Station (ISS) Human Research Facility (HRF). Subjects performed three different tasks with the Newton: (1) using the stylus to tap on different sections of the screen in order to launch an application and to select options within it; (2) using the stylus to write, and; (3) correcting handwriting recognition errors in a handwriting-intensive application. Subjects rated handwriting in microgravity 'Borderline' and had great difficulties finding a way in which to adequately restrain themselves at the lower body in order to have their hands free for the Newton. Handwriting recognition was rated 'Unacceptable,' but this issue is hardware-related and not unique to the microgravity environment. It is suggested that the restraint and handwriting issues are related and require further joint research with the current Handheld Electronic Logbook prototype: the Norand Pen*key Model #6300.

Berman, Andrea H.

Evaluation of the Universal Hand Tool for Metals Processing in Space

The Paton Welding Institute, Kiev, Ukraine, has developed the Universal Hand Tool for processing Metals in the space environment. The Universal is a hand held, 1 kilowatt electron beam welding tool designed to accept attachments to enable welding with and without filler wire, cutting, and coating by vapor deposition. The Marshall Space Flight Center, together with the Paton Institute, designed and developed the International Space Welding Experiment (ISWE) to demonstrate the Universal Welding System during an extravehicular activity on STS-87. ISWE was subsequently demanifested and has not been remanifested at this time. This paper describes the science objectives of ISWE, the safety hazards associated with manual welding in space and the associated resolutions, and the results of ground based development efforts. The Universal was adequate for processing the samples planned for ISWE and was successfully modified to meet shuttle payload constraints. Sample cleanliness and operator training proved to be the primary drivers for the quality of the processed samples.

Russell, Carolyn

Hand-Held Sunphotometers for High School Student Construction and Measuring Aerosol Optical Thickness

Science education is taking the teaching of science from a traditional (lecture) approach to a multidimensional sense-making approach which allows teachers to support students by providing exploratory experiences. Using projects is one way of providing students with opportunities to observe and participate in sense-making activity. We created a learning environment that fostered inquiry-based learning. Students were engaged in a variety of Inquiry activities that enabled them to work in cooperative planning teams where respect for each other was encouraged and their ability to grasp, transform and transfer information was enhanced. Summer, 1998: An air pollution workshop was conducted for high school students in the Medgar Evers College/Middle College High School Liberty Partnership Summer Program. Students learned the basics of meteorology: structure and composition of the atmosphere and the processes that cause weather. The highlight of this workshop was the building of hand-held sunphotometers, which measure the intensity of the sunlight striking the Earth. Summer, 1999: high school students conducted a research project which measured the mass and size of ambient particulates and enhanced our ability to observe through land based measurements changes in the optical depth of ambient aerosols over Brooklyn. Students used hand held Sunphotometers to collect data over a two week period and entered it into the NASA GISS database by way of the internet.

Almonor, Linda