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At least 721 records · Page 40

Study and development of techniques for automatic control of remote manipulators

An overall conceptual design for an autonomous control system of remote manipulators which utilizes feedback was constructed. The system consists of a description of the high-level capabilities of a model from which design algorithms are constructed. The autonomous capability is achieved through automatic planning and locally controlled execution of the plans. The operator gives his commands in high level task-oriented terms. The system transforms these commands into a plan. It uses built-in procedural knowledge of the problem domain and an internal model of the current state of the world.

Shaket, E.↗

Remote manipulator system steering capability for SVDS

Details of the remote manipulator system steering capability to be implemented into the space vehicle dynamics simulator are reported. The resolve rate law is included as part of the overall steering capability. The steering model includes three automatic modes, four manual augmented modes, and a single joint rate mode.

Martin, D. T.↗

Indicator tensor manipulation on MACSYMA

A new computational tool for physical calculations is described. It is the first computer system capable of performing indicial tensor calculus (as opposed to component tensor calculus). It is now operational on the symbolic manipulation system MACSYMA. The capabilities of the system are outlined.

Bogen, R. A.↗

Symbolic manipulation techniques for vibration analysis of laminated elliptic plates

A computational scheme is presented for the free vibration analysis of laminated composite elliptic plates. The scheme is based on Hamilton's principle, the Rayleigh-Ritz technique and symmetry considerations and is implemented with the aid of the MACSYMA symbolic manipulation system. The MACYSMA system, through differentiation, integration, and simplification of analytic expressions, produces highly-efficient FORTRAN code for the evaluation of the stiffness and mass coefficients. Multiple use is made of this code to obtain not only the frequencies and mode shapes of the plate, but also the derivatives of the frequencies with respect to various material and geometric parameters.

Andersen, C. M.↗

Varieties of operator manipulation

A change in MACSYMA syntax is proposed to accommodate the operator manipulators necessary to implement direct and indirect methods for the solution of differential equations, calculus of finite differences, and the fractional calculus, as well as their modern counterparts. To illustrate the benefits and convenience of this syntax extension, an example is given to show how MACSYMA's pattern-matching capability can be used to implement a particular set of operator identities which can then be used to obtain exact solutions to nonlinear differential equations.

Doohovskoy, A.↗

Force feedback systems in undersea manipulator applications

The manual control behavior of the operator with various levels of manipulator system complexity was studied in order to determine the relationships among control system dynamics, certain base engineering variables, controller designs and system performance. Based on the data obtained, a set of general transfer functions were prepared to provide a mathematical model of the various levels of potential force feedback fidelity as a function of force backlash present in alternate engineering designs.

Pesch, A. J.↗

Voice controlled adaptive manipulator and mobility systems for the severely handicapped

Efforts by NASA and the VA to apply available teleoperator/robot technology to rehabilitate amputees and spinal cord injured patients having severe loss of motor, manipulative, and sensory capabilities in the lower and/or upper extremities are summarized. Techniques developed include the control of a wheelchair by voice control or tongue chinswitch. The voice recognition computer and its operation are also described.

Heer, E.↗

Anthropomorphic master/slave manipulator system

An anthropomorphic master/slave manipulator system including master arm apparatus with a plurality of master tubular articulated portions is outlined. Objectives of this investion were to provide a system that accurately and smoothly simulates human limb movement at a remote location. The system has a high frequency response, a high structural stiffness and a design that protects the components of the slave mechanism. Simulation of human movements is possible in outer space, underwater, and in a hazardous environment such as in a high radiation area. The equivalent ability, dexterity, and strength of a human arm are simulated.

Vykukal, H. C.↗

Pattern recognition and control in manipulation

A new approach to the use of sensors in manipulator or robot control is discussed. The concept addresses the problem of contact or near-contact type of recognition of three-dimensional forms of objects by proprioceptive and/or exteroceptive sensors integrated with the terminal device. This recognition of object shapes both enhances and simplifies the automation of object handling. Several examples have been worked out for the 'Belgrade hand' and for a parallel jaw terminal device, both equipped with proprioceptive (position) and exteroceptive (proximity) sensors. The control applications are discussed in the framework of a multilevel man-machine system control. The control applications create interesting new issues which, in turn, invite novel theoretical considerations. An important issue is the problem of stability in control when the control is referenced to patterns.

Bejczy, A. K.↗

The LEMMA concept - A new manipulator

The LEMMA is a proposed conceptual design of a remote teleoperator manipulator arm with 6 degrees of freedom, exclusive of the end-effector. The bevel gear arrangement in 4 of the 6 degrees of freedom, together with the concentric-tubular arm configuration, requires a unique and novel drive mechanism. This differential drive assembly, housed in the shoulder, is a self-compensating device and simplifies the matrix solution for the resolved motion rate control system needed to guide the arm in its performances. The article will describe the need for the 6 degrees of freedom as established by the work envelope, the functioning of the differential shoulder drive, the arm and joint configuration, and the anticipated degree of accuracy.

Kersten, L.↗

Simulator for training remote-manipulator operators

Six-degree-of-freedom simulator uses economical components. Reduction in complexity makes this or similar system cost-effective for training manipulator operators, such as those in industries handling nuclear wastes and hazardous chemicals.

Orr, D. H.↗

Sampled data analysis of a computer-controlled manipulator

A comprehensive sampled data analysis of a computer-controlled manipulator is presented in terms of root loci for gain selection and transient responses to step input functions. All parameter values and their derivations where applicable were tabulated. The analysis, while quite specific, uses normalized gain parameters, which allows the results to be applied to any similar system regardless of individual hardware parameter values.

Markiewicz, B. R.↗

Primary reaction control system/remote manipulator system interaction with loaded arm. Space shuttle engineering and operations support

A study of the interaction between the orbiter primary reaction control system (PRCS) and the remote manipulator system (RMS) with a loaded arm is documented. This analysis was performed with the Payload Deployment and Retrieval Systems Simulation (PDRSS) program with the passive arm bending option. The passive-arm model simulates the arm as massless elastic links with locked joints. The study was divided into two parts. The first part was the evaluation of the response of the arm to step inputs (i.e. constant jet torques) about each of the orbiter body axes. The second part of the study was the evaluation of the response of the arm to minimum impulse primary RCS jet firings with both single pulse and pulse train inputs.

Taylor, E. C.↗

Robots and Manipulator Systems. Part 2

This book represents a conference on robots and manipulator systems. Topics discussed include: mathematical modeling systems integrators, the use of TV monitors for remote operation of machinery on earth and in space, an evaluation of various control modes, remotely piloted aircraft, undersea operations, and prosthetic devices for the physically handicapped.

Heer, E.↗

Remote manipulator for IC wafers

Mechanical manipulator automatically loads, transports, and unloads silicon wafers between processing stations in large-scale integrated-circuit fabrication facility at Marshall Space Flight Center thus eliminating need for human opeators at various stages in processing cycle. It also reduces possibility of wafer contamination.

Hudgins, J. L.↗

Coupler for remote manipulators

Reliable, low-cost coupler alines and grasps moving and rotating objects. Coupling mechanism may be used in handling of radio-active materials or in underwater explorations and other remote manipulators.

Rudmann, A. A.↗

Event-driven displays for manipulator control

The problem of constructing event-related information displays from multidimensional data generated by proximity, force-torque and tactile sensors integrated with the terminal device of a remotely controlled manipulator is considered. Event-driven displays are constructed by using appropriate algorithms acting on sensory data in real time. Event-driven information displays lessen the operator's workload and improve control performance. The paper describes and discusses several event-driven display examples that were implemented in the JPL teleoperator project, including a brief outline of the data handling system which drives the graphics display in real time. The paper concludes with a discussion of future plans to integrate event-driven displays with visual (TV) information.

Bejczy, A. K.↗