• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1036-1041
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• 1993

The tip of the flexible robot arm has to be controlled by the active control reducing vibration because it has residual vibration after getting to desired position. This paper presents an end-point position control of a 1-link flexible robot arm having tip mass by the PID control algorithm. The system is composed of a flexible arm with tip mass, dc servomotor and ballscrew mechanism under translational motion. The feedback signal composed of the tip displacement measured by laser sensor, estimated velocity and acceleration is used to control the base motion. Theoretical results are obtained by applying the Laplace transform and the numerical inversion method to the governing equations. After the flexible robot arm reaches to. the desired position, the residual vibration is controlled by the PID algorithm. This paper gives the simulation and experimental results of end-point responses according to changing tip-mass and arm length. And this algorithm shows good effects of reducing the residual vibration. Approximately, theoretical response is in good agreement with experimental one.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.592-601
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• 1992

Reach posture의 정확한 예측은 인간모형이 구현되어 있는 CAD시스템에서 인간공학적 평가를 하는데 있어서 중요한 역할을 한다. 인간 골격구조의 복잡성과 그 행위의 특성에 대한 연구의 부족으로 인해 연구성과가 미미한 어려운 분야라 하겠다. 본 연구에서는 인간을 로보트와 같은 Multi-link system으로 간주하고, 로보트 Kinematics를 적용하여 Reach posture를 예측하고자 한다. 상지는 Hip, 어깨, 팔꿈치와 손목관절로 구성된 8자유도의 Redundant manipulator가 되고, 하지는 Hip, 무릎과 발목관절의 6자유도 link system이 된다. 상지의 Reach posture는 Resolved motion method를 이용하고, 하지는 Pieper's method를 사용하여 예측한다. 상지에 대한 Reach posture예측결과를 인간이 실제로 취하는 자세를 Motion Analysis system으로 검증해 본 결과 유사한 결과를 보였다.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.484-491
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• 2002

We developed a new type of human-sized BWR (biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. A new type of actuator for the robot is proposed, which is composed of four bar link mechanism driven by the ball screw. The robot overcomes the limit of the driving torque of conventional BWRs. The BWR was designed to walk autonomously by adapting small DC motors for the robot actuators and has a space to board DC battery and controllers. In the performance test, the BWR performed sitting-up and down motion, and walking motion. Through the test, we found the possibility of a high performance biped-walking.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.63-64
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• 2006

In this paper, design modification was performed to improve the structure of ex-developed 12 D.O.F Biped walking robot, KUBIR-1 similar with human beings. The motion of KUBIR-1 was slow and had a limited walking space. Hence I designed an improved BWR named KUBIR-2 with 12 degree of freedom. KUBIR-2 was designed to solve the following problems of KUBIR-1. First, KUBIR-2 was more simply designed in the four-bar-link mechanism, and its weight was reduced. Second, it had the built-in controller and motor driver. Third, walking velocity of KUBIR-2 was increased by improvement of speed and motion joint angle range. In addition to these, we modified the structure of the foot for more stable walking.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.4
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• pp.449-454
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• 2010

The force control of a constrained flexible manipulators has been one of the major research topics. However, a little effort has been devoted for the relation between friction force and elastic deflection of end-effector for a constrained flexible manipulator. So, the aim of this paper is to clarify the friction mechanism of a constrained spatial multi-link flexible manipulator by changing the material and connected method of end-effector. In this study, a concise hybrid position/force control scheme is applied to the control of a flexible manipulator, and the experimental results for the constrained vertical motion and constrained horizontal motion is presented. Finally a comparison between these results are presented to show the reduction of vibration of link and friction force.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.515-522
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• 1991

Determining the motion using optimal technique about traveling time and trajectory planning has been studied often in recent years, but the study of determining the optimal robot dimensions is rare, the authors attempt to find out the least driving torques and energy as the optimization of link length ratio referred to 2R SCARA and 3R robot manipulators. For the given linear path with triangular velocity profile, the inverse kinematic and dynamic problems are examined in order to lead into solution of problem, which is suggested for optimal design of link lengths. Accordingly, optimal link length ratio is obtained with respect to each case.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.438-445
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• 2006

Due to the complicated character of the hemming process for automobile panels, it is very difficult to set up a consistent and reliable die design guide rule that does not require subtle decision of experienced experts during design stage and multiple trials during hemming die making. In this paper an automatic die design system of hemming units is pursued by presenting some algorithms, in which geometric data and constraints of the hemming units were converted to formula. two kinds of hemming units, 2-link type and 4-link type, were selected as examples and the geometries and kinematics of all parts were analyzed to build the design algorithm.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.511-516
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• 2000

In order to not only perform as a extreme model under the severe operating condition but also acquire more diverse and advanced control capability utilizing high compliance, active vibration control of a flexible 2-link robot manipulator are investigated. Multi variable-structured frequency shaped optimal sliding mode is proposed for the flexible robot manipulator like control system, whose control variables, an angular motion of joint and vibration of flexible link, have to be controlled simultaneously by one control torque at a driving joint. The control system is divided into two subsystems, a control input related subsystem and an added subsystem. The proposed sliding mode, composed of multi control variables, makes optimized relation between subsystems and a individual control input, thus, the sliding mode controller can compensate whole dynamics of each subsystems simultaneously. And the possibility and effectiveness are verified by vibration control of a manipulator having two flexible links. Simulation and experiment results show that the proposed control scheme achieves the purpose effectively.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.184-193
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• 2017

This work shows how to create an algorithm and implementation for motion and image matching between a vehicle simulator and Unity 3D based virtual object. The motion information of the virtual vehicle is transmitted to the real simulator via a RS232 communication protocol, and the motion is controlled based on the inverse kinematics solution of the platform adopting rotary-type six actuators driving system. Wash-out filters to implement the effective motion of the motion platform are adopted, and thereby reduce the dizziness and increase the realistic sense of motion. Furthermore, the simulator system is successfully designed aiming to reducing size and cost with adaptation of rotary-type six actuators, real driving environment via VR (Virtual Reality), and control schemes which employ a synchronization between 6 motors and 3rd order motion profiles. By providing relatively big sense of motion particularly in impact and straight motions mainly causing simulator sickness, dizziness is remarkably reduced, thereby enhancing the sense of realistic motion.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.91-96
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• 2006

The aim of this paper is to clarify the structural compliance of the constrained spatial flexible manipulator and to develop the force control by using the compliance of the links. Using the dependency of elastic deflections of links on contact force, vibrations for constrained vertical motion have been suppressed successfully by controlling the position of end-effector. However, for constrained horizontal motion, the vibrations cannot be suppressed by only controlling position of end-effector. We present the experimental results for constrained vertical motion, and constrained horizontal motion. Finally, a comparison between these results is presented to show the validity of link compliance.