• Title/Summary/Keyword: Serial Links

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Stiffness Analysis of Planar Parallel Manipulators with Serially Connected Legs (직렬체인 다리를 갖는 평면 병렬형 기구의 강성해석)

  • Kim, Han Sung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.2
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    • pp.164-172
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    • 2014
  • This paper presents a method for analyzing the stiffness of full and low DOF (degree of freedom) planar parallel manipulators with serially connected legs. The individual stiffness of each leg is obtained by applying reciprocal screws to the leg twist using passive joints and elastic elements consisting of actuators and links. Because the legs are connected in parallel, the manipulator stiffness is determined by summing the individual leg stiffness values. This method does not require the assumption that springs should be located along reciprocal screws and is applicable to a planar parallel manipulator with a generic or singular configuration. The stiffness values of three planar parallel manipulators with different DOFs are analyzed. The numerical results are confirmed using ADAMS S/W.

Design and Evaluation of a parallel EMG Signal Identifier using Trsnsputers (트랜스퓨터를 이용한 병렬 근신호 인식기의 설계 및 평가)

  • 김종원;김성환
    • Journal of Biomedical Engineering Research
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    • v.17 no.4
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    • pp.459-468
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    • 1996
  • This paper considers the problem of realising a parallel EMG identifier used in FES (functional electrical stimulation) system on a fixed dimension transputer array. This involves using an identifiestion algorithm in the wavelet transform domain. This algorithm have suggested by the authors in a previous paper(6). The transputer serial links permit higtlly varied and economic network-type connections and the structure enables rapid topological reconfiguration. Analysing the results Showed that the Speed-UPS ranged from 1.82 to 3.44 With 2-4 transputers for corresponding model order, and from 1.82 to 3.97 with increasing the model orders when two and four transputers are used respectively.

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Implementation of Android SmartPresenter Using Bluetooth-Based multi-Links Services (블루투스 기반 다중링크 서비스를 이용한 안드로이드 스마트 프리젠터 구현)

  • Yeo, Jong-Yun;Kang, Dong-Byeong;Shin, Sung-Hun;Jeong, Gu-Min
    • Proceedings of the Korea Information Processing Society Conference
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    • 2011.04a
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    • pp.707-708
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    • 2011
  • 본 논문에서는 최근 스마트폰의 보급이 활성화 되고 다양한 응용프로그램이 개발됨에 따라, 안드로이드를 이용하여 스마트 프리젠터를 구현한다. 스마트 프리젠터는 블루투스의 SPP(Serial Port Profile)와 A2DP(Advanced Audio Distribution Profile)을 이용해 다중링크를 구성하여 PC를 원격 제어하는 동시에 음성을 전송하여 마이크 기능을 수행하도록 구현한다.

Study on Dynamic Crawling of The Five-bar Planar Mechanism (5절 평면형 메커니즘의 동적 포복에 관한 연구)

  • Lee J.H.;Lim N.S.;Kim W.K.;Yi B.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1045-1049
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    • 2005
  • In this paper, the dynamic crawling of a five-bar planar mechanism is investigated. One complete cycle of the crawling selected in this study consists of four different steps, i) sliding at one contact point between the mechanism and the ground, ii) changing its configuration without sliding at two contact points, iii) sliding at the other contact point, and iv) again changing its configuration without sliding at two contact points. In this type of crawling, the crawling mechanism maintains the shape of the parallel structure throughout a complete crawling cycle. The modeling algorithm for serial manipulators proposed by M. Thomas and et al.[1] is employed by introducing imaginary joints and links which represent the contact interfaces between the one end of the mechanism and the ground, while the other end of the mechanism is regarded as an end-effector of the imaginary serial manipulator which treats the reaction force and torque at the contact point as external forces. Then, a complete cycle of dynamic crawling of the mechanism is investigated through various computer simulations. The simulation result show that the stable crawling characteristics of the mechanism could be secured when the proper configurations depending on specified frictional constraints are met.

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Design and Experimental Report for the Special 3D.O.F Robot Manipulator

  • Moon, Dong-Hee;Lee, Woon-Sung;Kim, Jung-Ha
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2000-2003
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    • 2003
  • In recent years, robots have been used widely in industrial field and have been expanded as a result of continuous research and development for high-speed and miniaturization. The goal of this paper is to design the serial manipulator through kinematic analysis and to control the position and orientation of end-effector with respect to time. In general, a structure of industrial robot consists of several links connected in series by various types of joints, typically revolute and prismatic joints. The movement of these joints is determined in inverse kinematic analysis. Compared to the complicated structure of parallel and hybrid robot, open loop system retains the characteristic that each link is independent and is controlled easily. AC servo motor is used to place the robot end-effector toward the accurate point with the desired speed and power while it is operated by position control algorithm. The robot end-effector should trace the given trajectory within the appropriate time. The trajectory of end-effector can be displayed on the monitor of general personal computer through Opengl program.

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The Estimation for the Forward Kinematic Solution of Stewart Platform Using the Neural Network (신경망 기법을 이용한 스튜어트 플랫폼의 순기구학 추정)

  • Lee, Hyung-Sang;Han, Myung-Chul;Lee, Min-Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.8
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    • pp.186-192
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    • 1999
  • This paper introduces a study of a method for the forward kinematic analysis, which finds the 6 DOF motions and velocities from the given six cylinder lengths in the Stewart platform. From the viewpoints of kinematics, the solution for the inverse kinematic is easily found by using the vectors of the links which are composed of the joint coordinates in base and plate frames, to act contrary to the serial manipulator, but forward kinematic is difficult because of the nonlinearity and complexity of the Stewart platform dynamic equation with the multi-solutions. Hence we, first in this study, introduce the linear estimator using the Luenberger's observer, and the estimator using the nonlinear measured model for the forward kinematic solutions. But it is difficult to find the parameter of the design for the estimation gain or to select the estimation gain and the constant steady state error exists. So this study suggests the estimator with the estimation gain to be learned by the neural network with the structure of multi-perceptron and the learning method using back propagation and shows the estimation performance using the simulation.

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KTM TOKAMAK OPERATION SCENARIOS SOFTWARE INFRASTRUCTURE

  • Pavlov, V.;Baystrukov, K.;Golobokov, Yu.;Ovchinnikov, A.;Mezentsev, A.;Merkulov, S.;Lee, A.;Tazhibayeva, I.;Shapovalov, G.
    • Nuclear Engineering and Technology
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    • v.46 no.5
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    • pp.667-674
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    • 2014
  • One of the largest problems for tokamak devices such as Kazakhstan Tokamak for Material Testing (KTM) is the operation scenarios' development and execution. Operation scenarios may be varied often, so a convenient hardware and software solution is required for scenario management and execution. Dozens of diagnostic and control subsystems with numerous configuration settings may be used in an experiment, so it is required to automate the subsystem configuration process to coordinate changes of the related settings and to prevent errors. Most of the diagnostic and control subsystems software at KTM was unified using an extra software layer, describing the hardware abstraction interface. The experiment sequence was described using a command language. The whole infrastructure was brought together by a universal communication protocol supporting various media, including Ethernet and serial links. The operation sequence execution infrastructure was used at KTM to carry out plasma experiments.

A study on the control-in-the-small characteristics of a planar parallel mechanism (평면형 병렬 메카니즘의 국소적 제어 특성에 관한 연구)

  • Kim, Whee-kuk;Cho, Whang;Kim, Jae-Seoub
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.3
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    • pp.360-371
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    • 1998
  • In this paper, output precision characteristics of a planar 6 degree-of-freedom parallel mechanisms are investigated, where the 6 degree-of-freedom mechanism is formed by adding an additional link along with an actuated joint in each serial subchain of the planar 3 degree-of-freedom parallel mechanism. Kinematic analysis for the parallel mechanism is performed, and its first-order kinematic characteristics are examined via kinematic isotropic index, maximum and minimum input-output velocity transmission ratios of the mechanisms. Based on this analysis, two types of planar 6 degrees-of-freedom parallel manipulators are selected. Then, dynamic characteristics of the two selected planar 6 degree-of-freedom parallel mechanisms, via Frobenius norms of inertia matrix and power modeling array, are investigated to compare the magnitudes of required control efforts of both three large actuators and three small actuators when the link lengths of three additional links are changed. It can be concluded from the analysis results that each of these two planar 6 degrees-of-freedom parallel mechanisms has an excellent control-in-the-small characteristics and therefore, it can be very effectively employed as a high-precision macro-micro manipulator when both its link lengths and locations of small and large actuators are properly chosen.

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Design of Sensor Network for Estimation of the Shape of Flexible Endoscope (연성 대장내시경의 형상추정을 위한 센서네트워크의 설계)

  • Lee, Jae-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.299-306
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    • 2016
  • In this paper, a method of shape prediction of an endoscope handling robot that can imitate a surgeon's behavior using a sensor network is suggested. Unit sensors, which are composed of a 3-axis magnetometer and 3-axis accelerometer pair comprise the network through CAN bus communication. Each unit of the sensor is used to detect the angle of the points in the longitudinal direction of the robot, which is made from a flexible tube. The signals received from the sensor network were filtered using a low pass Butterworth filter. Here, a Butterworth filter was designed for noise removal. Finally, the Euler angles were extracted from the signals, in which the noise was filtered by the low path Butterworth filter. Using this Euler angle, the position of each sensor on the sensor network is estimated. The robot body was assumed to consist of links and joints. The position of each sensor can be assumed to be attached to the center of each link. The position of each link was determined using the Euler angle and kinematics equation. The interpolation was carried out between the positions of the sensors to be able to connect each point smoothly and obtain the final posture of the endoscope in operation. The experimental results showed that the shape of the colonoscope can be visualized using the Euler angles evaluated from the sensor network suggested and the shape of serial link estimated from the kinematics chain model.

Molecular Epidemiological Analysis of Bloodstream Isolates of Candida albicans from a University Hospital over a Five-Year Period

  • Shin Jong Hee;Og Yu Gyung;Cho Duck;Kee Seung Jung;Shin Myung Geun;Suh Soon Pal;Ryang Dong Wook
    • Journal of Microbiology
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    • v.43 no.6
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    • pp.546-554
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    • 2005
  • We assessed the genetic relations and epidemiological links among bloodstream isolates of Candida albicans, which were obtained from a university hospital over a period of five years. The 54 bloodstream isolates from the 38 patients yielded 14 different karyotypes, 29 different patterns after digestion with SfiI (REAG-S), and 31 different patterns after digestion with BssHII (REAG-B) when analyzed using three different pulsed-field gel electrophoresis (PFGE) typing methods. In 11 patients with serial blood stream isolates, all strains from each patient had the same PFGE pattern. The dendrograms for all of the strains revealed that the distribution of similarity values ranged from 0.70 to 1.0 in the REAG-S patterns, and from 0.35 to 1.0 in the REAG-B patterns. Overall, the combination of the three different PFGE methods identified 31 distinct types, reflecting the results obtained using the REAG-B alone different. different Five PFGE types were shared among 22 isolates from 12 patients. These types of strains were more frequently associated with central venous catheter-related fungemia than the other 26 type strains $(92\%\;versus\;31\%;\;P<0.005)$. Of five PFGE types, four isolates were determined to be epidemiologically related: each of these types was primarily from two or three patients who had been hospitalized concurrently within the same intensive care unit. Our results suggest that the REAG-B constitutes perhaps the most useful PFGE method for investigating C. albicans candidemia and also shows that a relatively high proportion of C. albicans candidemia may be associated with exogenous acquisition of clonal strains.