• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.2
• /
• pp.116-122
• /
• 2022

This study proposed a method of testing the stability when selecting gears to reduce the weight of a 3-DOF wrist mechanism for a pick-and-place 3-DOF parallel robot with an increased workspace by using an additional straight axis at its top. We performed SolidWorks^® modeling- and ANSYS^®-based structural analysis of a pinion gear, which is most vulnerable to the force from a 3-DOF wrist mechanism, to lighten the robot weight for performing various tasks. When the initial analysis results considerably differed from the theoretical values calculated in advance, we checked and identified the errors in the contact conditions or input values. Ultimately, it is believed that the methodology presented in this paper will help in mitigating errors during analysis and determine the accurate values for a lightweight 3-DOF wrist mechanism for a parallel robot with an expanded workspace.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.3
• /
• pp.289-296
• /
• 2016

This study presents the kinematics of an intrinsic continuum robot actuated by pneumatic artificial muscles. The single section of a developed continuum robot consisted of three muscles in parallel. The contraction of each muscle according to applied air pressure produced spatial motions of a distal plate with respect to a base plate. Based on the bending behaviors of artificial muscles, the orientation and position of the end-effector of a continuum robot were formulated using a transformation matrix. The orientation and position was also determined for a single section of the distal plate. A Jacobian matrix relating the contraction rate or the pressure rate of the muscles to the velocity vector of the end-effector was calculated considering the assembled position of actuators between neighboring sections of the robot. Experimental results showed that the motions of the intrinsic continuum robot were accurately estimated by the proposed kinematics.

• Smart Media Journal
• /
• v.7 no.3
• /
• pp.51-56
• /
• 2018

Banana is the eighth most important crop in the world designated by the United Nations Food and Agriculture Organization (FAO). In terms of production, it is the fourth most harvested crop following wheat, rice, and corn, considered to be a promising food source for mankind as it is not only scrumptious but also rich in nutrients. However, abnormal cultivation methods that mankind has invented to breed bananas is currently pushing them to the state of extinction. The aim of this study is to develop information-rich digital contents that can easily and intriguingly convey information about steadily but certainly increasing risk of banana extinction. The end-users are middle and high school students who are assumed to be aware of the agricultural revolution through their school curriculum. The linear storytelling method was meant to encourage the end-users to be interested in the causes and processes in which banana has become endangered. For generating a natural interaction between the content and the end-users, a parallel, upper-lower structure was used, in which the relationship between the stories comprising several stages and the information graphic supporting each story is represented. This paper can support an information campaign about the endangered species.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.281-286
• /
• 1993

In this paper, a parallel link typed wrist is developed for robotic precision assembly. The developed wrist can make the corrective motion required for compensating lateral and tilting errors. The mechanism of this wrist is one example of a motion simulator generating 6 DOF motion in space by 6 actuators connected in paralle. To make the wrist more compact, miniature DC motors containing reduction gears and servo system were used. The parallel link architecture enables a high positioning accuracy and high nominal load capacity. In this study, inverse kinematic problem is solved by using a Denavet-Hartenberg method and a simulational result about workspace of the proposed parallel mechanism is obtained.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.10
• /
• pp.1035-1043
• /
• 2006

In this study, a translational 3-DOF parallel mechanism formed by constraining the Stewart Platform Mechanism is investigated. The translational 3-DOF parallel mechanism has three struts(3-UPS type serial subchains) and in addition, has a PPP type serial subchain in the middle of the mechanism. Firstly, the closed-form forward and reverse position solutions are derived for this mechanism. And analysis on kinematic characteristics using isotropic index of the Jacobian is conducted to examine effects of design parameters for the mechanism. Lastly, a prototype mechanism is implemented and the kinematic performance of the translational 3-DOF parallel mechanism was verified through experimental work.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.103.1-103.1
• /
• 2011

고체 산화물 연료전지(SOFC)는 크게 음극(anode), 양극(cathode), 전해질(electrolyte)로 구성되 있으며 연결자를 통해 직렬 또는 병렬로 연결된 형태로 발전장치 등에 활용되고 있다. 이중 연료의 산화반응을 담당하고 있는 연료전지의 음극으로 지금까지 Cobalt, Platinum, Palladium 등의 전이금속 또는 귀금속들이 사용되었지만 현재는 Nickel 또는 Nickel을 함유한 물질들 특히, Ni-YSZ 복합체가 주로 사용되고 있다. Ni-YSZ 복합체는 가격과 성능 등 여러가지 면에서 SOFC의 음극으로 사용하기에 가장 적합한 물질인데 특히 전지의 지지체 역할과 동시에 전극으로서의 역할도 병행해야하는 음극 지지형 SOFC의 경우 Ni-YSZ 복합체의 효용성을 더욱 커지게 된다. 본 연구에서는 SOFC의 음극물질로 가장 널리 쓰이고 있는 Ni-YSZ 복합체를 core shell 형태로 만들어 전도 path를 효율적으로 하고 그 특성을 최적화하기 위한 미세구조 및 소결 거동, 전기적 특성을 평가하였다.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.9
• /
• pp.952-958
• /
• 2009

This article presents a combined structure of serial and parallel mechanisms for a humanoid robot. The 3 DOF parallel structure is designed and added to the waist of the humanoid robot arm to give flexible bending and rotating motions. Forward and inverse kinematics of a serial and parallel robot have been analyzed to generate motions. Simulation studies of verifying kinematics solutions of the parallel robot have been done. Experimental studies of mimicking shake-hands motion have been conducted to show the feasibility and usability of the combined structure.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.798-800
• /
• 2009

본 논문은 급증하는 항공 교통량을 처리하기 위해 국제민간항공기구(ICAO)를 중심으로 연구되고 있는 차세대 항공관제를 위한 시스템 중 비행자료처리시스템에서 효율적인 비행계획 상태 관리를 위한 방법론을 제안하고 있다. 본 논문에서 제안하는 비행계획 상태 관리는 입력되는 새로운 전문 및 관제사의 입력과 시간 타이머에 의한 이벤트를 구분하는 처리 구조이며, 두 가지를 병렬 처리하는 방식을 이용해서 정확하고 빠른 비행계획 상태 관리를 제공한다. 이는 향후 많은 항공 교통량을 처리하기 위한 차세대 항공관제 시스템에 적용되는 것을 그 목적으로 한다.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.12 no.6
• /
• pp.193-204
• /
• 2008

This paper describes laboratory experiments modelling multiple tunnel construction in soft ground. A series of small-scale model tests have been conducted at approximately 1/50 scale in order to investigate the behaviours of existing tunnels in response to the construction of new tunnels in close proximity. The model tunnels were constructed in a consolidated Speswhite Kaolin clay using a tunnelling device involving an auger type cutter within a shield. Strain gauges and LVDTs were used for instrumenting the existing tunnels. The findings obtained from the analyses of these tests were compared to the field measurements involving the reconstruction of the Northern Line London Underground Ltd. tunnels at Old street, United Kingdom. The results were also compared to the ground movement measurements obtained from a separate set of tests undertaken using the same apparatus and experimental procedures.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.11
• /
• pp.138-147
• /
• 2001

Alignment systems are frequently used under various semiconductor manufacturing environment. Particularly in PDP(Plasma Display Panel) manufacturing process, the alignment system is applied to the combining and sealing processes of the upper and lower glass panels of PDP, where these processes are performed in the vacuum chamber of high vacuum and high temperature. In this paper, the XYΘ-alignment stage is developed to align PDP panels. Because of high vacuum and high temperature environment, the alignment chamber has been designed to isolate the inner part of the alignment chamber from the outer environment of high vacuum and high temperature, in which every part of the alignment stage is inserted. As it is difficult to attach feedback sensors to the alignment stage in the alignment chamber, the alignment stage is implemented with the open loop algorithm, where the parallel link structure has been designed using step-motors and ball-screws for structural simplicity. The kinematic analysis is performed to drive the parallel link structure, based on the experiments of actuation-compensation of the alignment stage. For the error compensation, the hyperpatch model has been used to model the errors. From the experiments, the positional accuracy of the alignment stage can be improved significantly.