병렬기구 공작기계의 프로그램 개발

박근우(Kun-Woo Park),김태성(Tae-Sung Kim),최병오(Buyng-Oh Choi),이민기(Min-Ki Lee) 한국생산제조학회 2000 한국공작기계학회 춘계학술대회논문집 Vol.2000 No.4

2단 평행기구 로봇 암의 실시간 순방향 기구학 해석

이민기,박근우,Lee, Min-Ki,Park, Kun-Woo 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.1

The determination of the direct kinematics of the parallel mechanism is a difficult problem but has to be solved for any practical use. This paper presents the efficient formulation of the direct kinematics for double parallel robot arm. The robot arm consists of two parallel mechanism, which generate positional and orientational motions, respectively. These motions are decoupled by a passive central axis which is composed of four revolute joints and one prismatic joint. For a set of given lengths of linear actuators, the direct kinematics will find the joint displacements of th central axis from geometric constraints in each parallel mechanism. Then the joint displacements will be converted into the position and the orientation of the end effector of the robot arm. The proposed formulation is decoupled and compacted so that it will be implemented as a real-time direct kinematics. With the proposed formulation, we analyze the motion of the double parallel robot and show its characteristics. Specially, we investigate the workspace in terms of positional space as well as orientational space.

병렬기구형 공작기졔의 기구학적 보정에 관한 연구

이민기,김태성,박근우,Lee, Min-Ki,Kim, Tae-Sung,Park, Kun-Woo 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.11

This research develops a low-cost and high accuracy kinematic calibration method based on the following principles: 1) the platform locations are accurately measured by a constrained movement to inspect a calibration target; 2) the constrained movement is chosen to guarantee the parameter observability; 3) the mechanical fixture to constrain the movement and the sensor to check the constrained movement are implemented by low-cost and high-accuracy devices; 4) the calibration is easily done at an industrial environment. The kinematic parameters calibrated with respect to a single plane aren't influenced due to the misalignment of the plane. A parameter observability is successfully obtained even through one planar constraint, which guarantees that all kinematic parameters are estimated by minimizing the cost function.

병렬기구 보행로봇의 최적설계와 걸음새에 관한 연구

김치효(Chi Hyo Kim),박근우(Kun Woo Park),김태성(Tae Sung Kim),이민기(Min Ki Lee) Korean Society for Precision Engineering 2009 한국정밀공학회지 Vol.26 No.10

This paper presents a parallel typed walking robot which can walk in omni-direction and climb from a floor to a wall. We design a six D.O.F leg mechanism composed of three legs, which form a parallel mechanism with a base and a ground to generate arbitrary poses. Optimal design is conducted to maximize the walking space and the dexterity, which are normalized by the stroke of leg. Kinematic parameters are found to maximize the weighted optimal objectives. We design a triple parallel mechanism robot by inserting Stewart platform between the upper leg mechanism and the lower leg mechanism and examine the gaits when the robot walks on the ground and climbs from a floor to a wall. The analysis of walking space and dexterity for each gait shows that the triple parallel walking robot has a large walking space with a large stability region. We explore the possibility that the robot can climb from a floor to a wall. Investigating the gaits for the six steps proves that the robot can lift the foot up to the wall by combining the orientational walking space generated by three parallel mechanisms.

구속 메카니즘을 갖는 3-dof 병렬기구형 공작기계의 최적설계에 관한 연구

김치효(Chi-Hyo Kim),박근우(Kun-Woo Park),경진호(Jin-Ho Kyung) 한국생산제조학회 2007 한국공작기계학회 춘계학술대회논문집 Vol.2007 No.-

This paper studies on the optimal design of a robot manipulator combined a parallel manipulator and wrist manipulator(PMWM). The robot has a parallel manipulator with three linear actuators and a central axis for positional motions, i.e., x, y, and z and a wrist manipulator with two rotary actuators for rotational motions, i.e., yaw and pitch. We define parameters for optimal design such as radii of a base and a platform, the length and the stroke of linear actuator. The degree of improvement attainable is quantified by optimizing the manipulator design with respect to a weighted sum of the dexterity, the workspace volume, and the height. An object function is defined and maximized by the optimal parameters.

수중로봇의 롤 운동제어를 위한 모델 베이스 제어에 관한연구

김치효(Chi-Hyo Kim),박근우(Woo-Kun Park),김태성(Tae-Sung Kim),이민기(Min-Ki Lee) 한국항해항만학회 2009 한국항해항만학회지 Vol.33 No.5

We have been developing an underwater robot for harbour construction using a parallel mechanism. The robot is attached to the rope of a crane, which carries a large stone into the undersea The robot's yaw) and pitch are controlled by hydraulic cylinders but its roll is uncontrollable. We mount propellers in both side of the robot to generate the roll motion. This paper studies on the control for the roll motion of a underwater robot. A gyro-sensor is used to measure the angle in a roll motion. We develop the dynamic model to describe the robot's roll motion by a second order non-linear system and identify the model parameters by recursive least square and adaptive identifier. PD control, recursive model based control and adaptive model based control are applied with the dynamic model which computes the control input to compensate disturbances. This paper introduces the underwater robot system and presents the simulated and experimental results of the proposed controller. 병렬기구를 이용하여 항만공사를 위한 수중로봇을 개발하였다. 수중으로 큰 피복석을 옮기기 위해 수중로봇은 크레인에 의해 권양된다. 수중로봇의 요오와 피치운동은 유압 실린더에 의해 제어되지만 롤 운동은 제어되지 않는다. 롤 운동을 위해 로봇 양쪽에 프로펠러가 장착되어 제어된다. 본 논문은 수중로봇의 롤 운동제어에 관한 것이다. 롤 운동 각도를 측정하기 위해 자이로 센서가 사용되었다. 로봇의 롤 운동을 2차 비선형 시스템으로 나타내고 반복 리스트 스퀘어 방법과 적응인식 방법으로 동적 모델을 찾았다. 통적모델로 외란을 보상하기 위한 제어입력을 계산하고 PD 제어, 반복 리스트 스퀘어 모델 베이스 제어, 적응 모델 베이스 제어를 롤 운동제어에 적용했다. 수중로봇의 시스템을 설명하고 제안한 제어기의 시뮬레이션과 실험결과를 보인다.

보행공간과 안정성 향상을 위한 병렬기구 보행로봇의 설계

김치효(Chi Hyo Kim),박근우(Kun Woo Park),김태성(Tae Sung Kim),이민기(Min Ki Lee) 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.4

This paper presents a parallel typed walking robot to improve walking space and stability region. The robot is designed by inserting an intermediate mechanism between upper leg mechanism and lower leg mechanism. The leg mechanism is composed of three legs and base, which form a parallel mechanism with ground. Seven different types of walking robot are invented by combining the leg mechanisms and an intermediate mechanism. Topology is applied to design the leg mechanism. A motor vector is adopted to determine Jacobian and a wrench vector is used to analyze dynamics of the robot. We explore the stability region of the robot from the reaction force of legs and compute ZMP including the holding force to contact the foot to a wall. This investigates a walking stability when the robot walks on the ground as well as on the wall. We examine the walking space generated by support legs and by swing legs. The robot has both a large positional walking space and a large orientational walking space so that it can climb from a floor up to a wall.

국제결혼 이주여성의 정신건강에 영향을 미치는 요인 - 전라남도 거주 국제결혼 이주여성을 중심으로 : 국제결혼 이주여성의 정신건강에 영향을 미치는 요인

권구영(Kweon Gu Young),박근우(Park Kun Woo) 한국사회조사연구소 2007 사회연구 Vol.- No.14

최근 10여년 사이에 급격하게 증가하고 있는 국제결혼 이주여성들이 부적응적 상태에 있는 경우가 많아 사회통합은 물론 가족 관계 및 자녀 양육 등에도 상당한 어려움을 경험하고 있는 것이 현실이다. 이에 이 연구에서는 정신건강이 적응 및 사회통합과 밀접한 관련이 있다는 기존연구를 바탕으로, 광주·전남지역 거주 국제결혼 이주여성을 대상으로 생태체계적 요인들이 국제결혼 이주여성의 정신건강에 미치는 영향을 살펴보았다. 연구 결과, 국제결혼 이주여성의 문화적응스트레스, 가족관계스트레스 및 사회적 지지는 상호 유의한 상관관계를 가지고 있었다. 아울러 이들과 정신건강 사이에도 유의한 정적 혹은 부적 상관관계가 있었다. 그러나 교육수준, 결혼이유, 거주지 등을 통제한 후 이들이 정신건강에 미치는 영향을 살펴본 결과 문화적응스트레스와 사회적 지지는 국제결혼 이주여성의 정신건강에 유의한 영향력을 가지고 있었으며, 가족관계스트레스는 유의한 영향력을 갖지 않는 것으로 나타났다. 이상의 연구 결과를 바탕으로, 이 연구에서는 국제결혼 이주여성에 대한 개입체계를 입국 전 및 입국 초기에 집중하는 개입체계로 전환하고 포괄적 사례관리를 제공할 것과 함께 경제적 지원 및 사회참여 증진, 사회적 지지망 구축 지원 등이 필요함을 제언하였다. Large number of foreign wives are having a difficult time in forming family relations and rearing children due to maladjustment to social environment. In response, this study looks into the factors that affect on their mental health, assuming that mental health has a close relation with foreign wife"s social integration degree. The results has shown that foreign wife"s cultural adaptation stress, family relationship stress, and social support factors were correlated with each other. Also, cultural adaptation stress and social support appeared to be influential factors on foreign wife"s mental health with hierarchical regression analysis. Based on the results, the study proposes that comprehensive case management focusing on the pre-intervention and a switch of social plans, financial supports and networking social support systems.

프로펠러 연삭작업을 위한 병렬-직렬 로보트 암 개발

이민기(Min Ki Lee),최병오(Byung Oh Choi),정종윤(Jong Yoon Jung),박근우(Kun Woo Park) Korean Society for Precision Engineering 1996 한국정밀공학회지 Vol.13 No.2

4족 병렬기구 보행로봇의 능수능란성에 관한 연구

김치효(Chi Hyo Kim),김성주(Sung Joo Kim),박근우(Kun Woo Park),김태성(Tae Sung Kim),이민기(Min Ki Lee) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

This paper analyzes the dexterity of a four legged parallel walking robot. Topology design is conducted for a leg mechanism composed of four legs, base and ground, which constitute a redundant parallel mechanism. This mechanism is subdivided to four sub-mechanism composed of three legs. A motor vector is adopted to determine the 6x8 Jacobian of the redundant parallel mechanism and the 6x6 Jacobian of the sub-mechanisms, respectively. The condition number of the Jacobian matrices is used as an index to measure a dexterity. We analyze the condition numbers of the Jacobians over the positional walking space and the orientational walking space. The analysis shows that a sub-mechanism has lots of singularities within workspace but they are removed by a redundant parallel mechanism improving a dexterity. From the results, we can propose a parallel typed walking robot to enlarge walking space and stability region. The robot is designed by inserting an intermediate mechanism between upper and lower leg mechanisms. The robot is reasonably small so that it can climb from a floor to a wall.