• 제어로봇시스템학회논문지
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• 제6권1호
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• pp.66-72
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• 2000

As the demand for the design of modular manipulators or special purpose manipulators has increased, task based design to design an optimal manipulator for a given task become more and more important. However, the complexity with a large number of design parameters, and highly nonlinear and implicit functions are characteristics of a general manipulator design. To achieve the goal of task based design, it is necessary to develop a methodology to solve the complexity. This paper addresses how to determine the kinematic parameters of a two-degrees of freedom manipulator with parallelogram five-bar link mechanism from a given task, namely, how to map a given task into the kinematic parameters. With simplified example of designing a manipulator with five-bar link mechanism, the methodology for task based design is presented. And it introduces formulations of a given task and manipulator specifications, and presents a new dexterity measure for manipulator design. Also the optimization problem with constraints is solved by using a genetic algorithm that provides robust search in complex spaces.

• 문화기술의 융합
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• 제6권1호
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• pp.515-520
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• 2020

본 연구에서는 4절 평행 링크의 설계와 실제 구현에 대한 것으로 평행 4절 링크는 한축의 회전을 다른 축의 회전 운동으로 전달하기 위한 기본적인 기구학적 메카니즘으로 널리 이용되고 있다. 그런데 평행 4절 링크는 운동 도중에 전환점에서 위상 역전이 발생하는 문제가 발생하여 실제 구현에서는 이를 고려하여 설계하여야 한다. 링크 역전을 방지하기 위해서는 추가적인 위상 역전 억제용 링크를 옵셋을 두어 붙이는 2중 평행 사변형 형태의 링크를 제작하면 되는 것으로 일부 알려져 있으나 실제 제작하여 실험한 결과 전환점에서 운동이 부드럽지 않은 현상이 발생하였다. 본 연구에서는 이 문제를 해결하기 위해 위상 역전 방지를 위한 옵셋을 주는 링크외에 보조적으로 평활한 운동을 위한 링크를 추가시켜 피동축이 구동축을 따라 회전할 때에 특정지점에서 위상 역전이 발생하지 않고 평활한 운동을 수행하는 것을 확인 할 수 있었다.

• 한국산업융합학회 논문집
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• 제23권2_2호
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• pp.313-321
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• 2020

In this paper, two types of linear actuation methods for the previously proposed adaptive gripper are presented, which includes actual parallelogram inside a five-bar mechanism and has the advantages of smaller actuation torque and larger stroke over the commercial adaptive gripper by RobotiQ. The forward/inverse kinematics and statics analyses for two types of linear actuations are derived. From the inverse kinematics and statics analyses, linear actuation type I is selected and the gripper prototype is designed.

• 한국공작기계학회논문집
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• 제15권3호
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• pp.111-119
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• 2006

The ultra-precision stage is demanded for some industrial fields such as semiconductor lithography, ultra-precision machining, and fabrication of nano structure. A new stage was developed for those applications in order to obtain nano meter resolution. This stage consists of symmetric double parallelogram mechanism using flexure hinges. The mechanical properties such as strength of the flexures and deformations along the applied force were analyzed using FEM. The stage is actuated by a piezoelectric actuator and its movement was measured by a ultra-precision linear encoder. In order to improve positioning performance, a PID controller was designed based on the identified second order transfer function. Experimental results showed that this stage could be positioned within below 5 nm resolution irrespective of hysteresis and creep by the controller.

• Journal of Advanced Marine Engineering and Technology
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• 제26권5호
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• pp.581-588
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• 2002

A fuzzy learning control algorithm is proposed in this paper. In this method, two fuzzy controllers are used as a feedback and a feedforward type. The fuzzy feedback controller can be designed using simple knowledge for the controlled system. On the other hand, the fuzzy feedforward controller has a self-organizing mechanism and therefore, it does not need any knowledge in advance. The effectiveness of the proposed algorithm is demonstrated by experiment on the position and force control problem of a parallelogram type robot manipulator with two degrees of freedom. It is shown that the rapid learning and the robustness can be achieved by adopting the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2370-2372
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• 1998

Recently we have developed an active stereo head-eye system with vergence, name it KIST HECter(Head-Eye System with Colored Stero Vision), based on the analysis of human's neck and eye motion at visual behavior. Our HECter is a five degree-of-freedom system composed of pan and tilt motion in neck part and independent vergence motion of binocular cameras and commonly shared elevation axis in eye part. And stereo vision Provides two color image, which are processed by powerful each TMS32080 vision board. The shape and size are designed to be almost same as human face. The ability to vergence has significant importance and gives many beneficial merits. On its mechanical implementation we adapt a non-parallelogram 4-bar linkage mechanism since it provides high accuracy in transfering motion and enables compact and flexible design.

• 한국산업융합학회 논문집
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• 제22권3호
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• pp.325-335
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• 2019

In this paper, a novel adaptive gripper with underactuation is presented, which can change its configuration to parallel or power grip mode according to object shapes. Differently from the commercial adaptive gripper by RobotiQ, the proposed gripper includes an actual parallelogram inside a five-bar mechanism, which allows the free selection of actuator locations and can reduce actuation torques effectively. The forward and inverse kinematics for two grip modes and statics analysis have been analyzed. From the comparative design, the proposed gripper has about 20% smaller size, 3.7% larger stroke, and 30.5% smaller average actuation torque than the commercial one.

• 한국산학기술학회논문지
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• 제12권5호
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• pp.2031-2037
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• 2011

최근의 냉장고 등에 채택되고 있는 프렌치 도어는 2개의 도어를 사용하지만, 내부에 칸막이가 없어 내부 공간을 효율적으로 사용할 수 있는 장점이 있다. 그러나 프렌치 도어는 2개의 도어와 몸체와의 밀폐를 위해 부착된 개스킷이 서로 간섭을 일으키기 때문에 개스킷의 마모로 인해 밀폐성능에 치명적인 영향을 미치고 도어의 개폐력이 증가되는 문제점이 있다. 본 연구에서는 프렌치 도어의 개폐를 위해 4절 링크기구의 동작을 이용한 개폐 메커니즘을 개발하였다. 또한, 개발된 4절 링크기구를 설계 및 제작한 후 실제 냉장고에 적용하여 간섭이 발생하지 않음을 검증하였고, 개방력도 저감됨을 확인하였다. 본 연구에서 제안된 메커니즘은 냉장고뿐만 아니라 프렌치 도어를 채택하는 다른 가전제품이나 산업제품에도 적용될 수 있다.

• 대한기계학회논문집A
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• 제36권1호
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• pp.73-79
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• 2012

키오스크는 주차장, 고속도로 등에서 드라이브 스루 시스템에 적용되어, 운전자에게 다양한 서비스를 제공하고 있다. 그러나 기존의 키오스크는 서비스를 제공하기 위한 키오스크 패널이 고정되어 있어 적절한 위치에 정차하지 못할 경우 패널 조작이 어려웠다. 이러한 문제를 해결하기 위하여 본 연구에서는 사용자의 위치에 따라 키오스크 패널의 위치를 능동적으로 조절할 수 있는 머니퓰레이터를 개발 하였다. 제품의 저가화를 위하여 능동관절의 수를 최소화하였으며, 평행사변형 메커니즘과 수동관절을 구성하여 부족한 자유도를 보완하였다. 또한, 스프링과 캠 기반의 안전기구를 장착하여 키오스크 패널과 사용자 사이의 충돌 안전성을 확보하였다. 실험을 통해 머니퓰레이터의 위치제어 성능과 충돌 안전성을 검증하였으며, 충돌대응 전략을 적용하여 안전하게 키오스크를 운용할 수 있음을 확인하였다.

• 한국기계가공학회지
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• 제21권8호
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• pp.9-18
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• 2022

As the COVID-19 continues, the demand for robotic technology that can be applied in face-to-face tasks such as delivery and transportation, is increasing. Although these technologies have been developed and applied in various industries, the robots can only be operated in a tidy indoor environment and have limitations in terms of payload. To overcome these problems, we developed a 2 degree of freedom(DOF) environmental adaptive robot leg with a double 1-DOF counterbalance mechanism (CBM) based on wire roller. The double 1-DOF CBM is applied to the two revolute joints of the proposed robot leg to compensate for the weight of the mobile robot platform and part of the payload. In addition, the link of the robot leg is designed in a parallelogram structure based on a belt pulley to enable efficient control of the mobile platform. In this study, we propose the principle and structure of the CBM that is suitable for the robot leg, and design of the counterbalance robot leg module for the environment-adaptive control. Further, we verify the performance of the proposed counterbalance robot leg by using dynamic simulations and experiments.