2,591 research outputs found

    Bilateral Control with Task Learning and Adaptation to Environment

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    The Motion Copying System permits to save an operator task in terms of position and force references for the action reproduction whenever the operator isn't available or to train new users. This thesis analyzes the MCS design and limitations, the Bilateral Control System on which the MCS is based, and proposes a model to adapt the saved task to new environmental conditions

    Online Recognition of Environment Properties by Using Bilateral Control

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    The topic of this thesis is identification of the mechanical impedance of an unknown environment. Through the use of bilateral control based on DOB and RFOB structures, position, speed and force information are gathered and analyzed while performing continuous contact with the environment. The nonlinear Hunt-Crossley model is preferred over the classic Kelvin-Voigt model. Particular attention is given to the precise recognition of contact and the detection of an occurring deformation.ope

    Shokkakugaku ni motozuku ningen no sosa no jitsugen

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    Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 212

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    A bibliography listing 146 reports, articles, and other documents introduced into the NASA scientific and technical information system is presented. The subject coverage concentrates on the biological, psychological, and environmental factors involved in atmospheric and interplanetary flight. Related topics such as sanitary problems, pharmacology, toxicology, safety and survival, life support systems, and exobiology are also given attention

    Robotics for nuclear waste handling

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    This research focuses on the development of the control system of a dual arm industrial robot. A controller for the position control of unconstrained robot arm is also presented. System architecture, hardware configuration and software development are discussed in detail; The experimental set-up consists Remotec\u27s RM-10A dual arm manipulator. Each arm has six separate motorized motions with position sensors. The manipulator is controlled by a Texas Istruments\u27 TMS320C40 parallel Digital Signal Processors installed on the QPC/C40B Board. The PID control software which is embedded on the Digital Signal Processor is developed using C language. A Graphical User Interface is also developed using Microsoft Visual C{dollar}\sp{++}{dollar} to facilitate easy operation of the robot

    Cooperative control of dual arm manipulator

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    This research focuses on the development of a controller for the cooperation control of dual arm mechanical manipulator. A controller for the position control of unconstrained robot arm without velocity measurements is also presented; The experimental set-up consists Remotec\u27s RM-10A dual arm manipulator. Each arm has six separate motorized motions with position sensors. The arm has also an end effector and is provided with a six axes Force/Torque sensor. The manipulator is controlled by two TMS320C40 parallel Digital Signal Processors. The control software which is embedded on the Digital Signal Processor is developed using C language. A Graphical User Interface is also developed using Microsoft Visual C++ to facilitate easy operation of the robot; A PID controller is implemented for the position control of the manipulator. Experiments are performed both in joint space and in Cartesian space and the results are presented

    Safe code transfromations for speculative execution in real-time systems

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    Although compiler optimization techniques are standard and successful in non-real-time systems, if naively applied, they can destroy safety guarantees and deadlines in hard real-time systems. For this reason, real-time systems developers have tended to avoid automatic compiler optimization of their code. However, real-time applications in several areas have been growing substantially in size and complexity in recent years. This size and complexity makes it impossible for real-time programmers to write optimal code, and consequently indicates a need for compiler optimization. Recently researchers have developed or modified analyses and transformations to improve performance without degrading worst-case execution times. Moreover, these optimization techniques can sometimes transform programs which may not meet constraints/deadlines, or which result in timeouts, into deadline-satisfying programs. One such technique, speculative execution, also used for example in parallel computing and databases, can enhance performance by executing parts of the code whose execution may or may not be needed. In some cases, rollback is necessary if the computation turns out to be invalid. However, speculative execution must be applied carefully to real-time systems so that the worst-case execution path is not extended. Deterministic worst-case execution for satisfying hard real-time constraints, and speculative execution with rollback for improving average-case throughput, appear to lie on opposite ends of a spectrum of performance requirements and strategies. Deterministic worst-case execution for satisfying hard real-time constraints, and speculative execution with rollback for improving average-case throughput, appear to lie on opposite ends of a spectrum of performance requirements and strategies. Nonetheless, this thesis shows that there are situations in which speculative execution can improve the performance of a hard real-time system, either by enhancing average performance while not affecting the worst-case, or by actually decreasing the worst-case execution time. The thesis proposes a set of compiler transformation rules to identify opportunities for speculative execution and to transform the code. Proofs for semantic correctness and timeliness preservation are provided to verify safety of applying transformation rules to real-time systems. Moreover, an extensive experiment using simulation of randomly generated real-time programs have been conducted to evaluate applicability and profitability of speculative execution. The simulation results indicate that speculative execution improves average execution time and program timeliness. Finally, a prototype implementation is described in which these transformations can be evaluated for realistic applications

    Developing a labview based thermally stimulated current (tsc) controller to measure residual charge in electrospinning

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    Electrospinning is an electrohydrodynamic process for the fabrication of nanofibers which are widely used in therapeutical tissue engineering approaches. It utilizes the potential difference of an electrostatic field to overcome the surface tension of the polymer solution to extrude a fine jet of fluid which deposits on the grounded collector as a nanofiber mat. Using this process, nanofibers with diameters less than a micron can be produced. Previous studies have shown the presence of residual charge in electrospun nanofibers. The presence and decay of residual charge during cell culture media is still unknown. In an attempt to clarify the presence or absence of residual charge during cell culture, a LabVIEW based Thermally Stimulated Current controller is designed. The LabVIEW controller encapsulates the temperature and the electrometer control using RS- 485 and GPIB interfaces. The controller outputs a Temperature-Current plot which is the Thermally Stimulated Current spectrum. The current observed at the melting point of the electrospun material is a direct measure of the residual charge trapped within the nanofiber mat. Using this technique electrospun PolyCaproLactone (PCL) mats are analyzed before and after immersion in culture media and Phosphate Buffer Solution (PBS) for 1, 4 and 7 days
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