• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.238-247
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• 2014

The milking robot system is very important to detect correctly the teats position in the moving condition of cow. Also, the robot manipulator must control tracking the teat cup to the detected teat position. The presented milking robot is designed using the one point laser sensor for teat position detection. The teats of cow are detected by the laser scanning unit and the manipulator has the function of 3 axes moving control unit. The presented teat detection method and the electrical driving manipulator have the advantages of a simple, low cost and very quiet. The designed manipulator is realized by the totally electrical motor and servo poison control algorithm with velocity PID compensation. The presented robot is realized using the teat detection unit, 4 teat cups, 3 axes robot arm, 6 servo motors and automatic milking control line. The designed robot is experimented in the cow farm and is satisfied with the designed performance specification for milking robot manipulator.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.533-535
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• 2021

본 연구에서는 서비스 역할을 수행하는 6축 모듈형 매니퓰레이터 개발을 목표로 하며, 최종 기술 사양에 따른 설계를 진행하는 과정에서 기구의 섬세한 동작을 효율적으로 제어하기 위해 로봇 제어 소프트웨어의 오픈소스 환경인 ROS를 사용한다. 매니퓰레이터의 동작 설계를 ROS 기반에서 제어하기 위해 중요한 기본 환경을 구축하였으며, 특히 로봇 모델링을 위한 시각화를 위해 URDF파일에 해당 매니퓰레이터의 필수 파라미터값들을 지정하여 적용하였고, 전체 동작 시나리오에 맞춰 매니퓰레이터가 특정 자세를 취할 경우의 역기구학적인 해석과 그에 따른 경로를 생성하도록 매니퓰레이터의 라이브러리인 MoveIt을 활용하여 시각적으로 표현하고 시뮬레이션을 수행하였다. 또한, 설계한 ROS 환경 설계 방법을 바탕으로 MCU와의 통신을 통해 모터의 실시간 각도 값을 제어하고, 3D 깊이 카메라의 거리정보와 이미지 정보의 융합을 통해 로봇의 서비스 내용의 개선을 기대할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.192-197
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• 2001

Recent requirements for the fast and accurate motion in industrial robot manipulators need more advanced control techniques. To satisfy the requirements, importance of the force control is being continuously increased and the expensive force sensor is often installed to obtain the contact force information in practice. This information is indispensable for the force control of maintaining the desired contact force. However, the sensor cost is too high to be used in industrial applications. In this paper, it is proposed to estimate the contact force occurred between the end-effector of robots and environment in 3-D. The contact force monitoring system is developed based on the static and dynamic models of 3 DOF robot manipulators, where the contact force is described with respect to the link torque. The Extended Kalman Filter is designed and its performance is verified in simulations.

• Journal of Bio-Environment Control
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• v.12 no.2
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• pp.57-62
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• 2003

In this study, a robotic manipulator for harvesting cucumber was developed. The objective of this research was to design and to construct a robotic manipulator specifically tailored to harvest cucumber in the greenhouse. The system was consisted of an integrated end-efffctor, an image processing system and a controlling system. Especially, the image processing system detected the quality of cucumber within each plant in order for the computer to furnish harvest instructions to the manipulator. In all tests of cucumber, the success rate for cucumber harvest was 84％ in the greenhouse. End-effector, image processing system and controlling system showed good performance. Based on the results of this research the following recommendations are made for further study. Besides harvesting cucumbers, the oldest leaves, creepers and the youngest small side leaves need to be removed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.524-527
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• 2002

This paper is on the development of an educational 6-axis articulated manipulator using 4-bar linkage system. Especially, the 2$^{nd}$ and the 3$^{rd}$ axes need large torque to control the movement of an end-effect. However, small motors (RC-servo, DC-gear, stepping meters) are used for the 4-bar linkage. In addition the manipulator can be operated by a switch and also motion can be realized automatically, based on C-language coded users programs..

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.1
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• pp.47-53
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• 2004

An electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is quite difficult to obtain stable control performance. We have applied a disturbance estimation and compensation type robust control to all the axes in a 6-link electro-hydraulic manipulator. It was confirmed that the performance of trajectory tracking and attitude regulating was greatly improved by the disturbance observer. For autonomous assembly tasks, it is said that compliance control is one of the most popular methods in contact task. We have proposed a compliance control based on the position control by a disturbance observer for our manipulator system. To realize more stable contact work, the states in the compliance loop are feedbacked, where not only displacement but also the velocity and acceleration are considered. We have also applied this compliance control to the Peg-in-Hole insertion task and proposed new methods of (1)rotating of the end-effector periodically in order to reduce the friction force, (2)random searching for the center of a hole and (3)trajectory modification to reduce the impact force. As a result of these new methods, it could be experimentally confirmed that the Peg-in-Hole insertion task with a clearance of 0.007 [mm] could be achieved.