• The Journal of Korea Robotics Society
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• v.9 no.2
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• pp.111-116
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• 2014

Human-robot co-operation becomes increasingly frequent due to the widespread use of service robots. However, during such co-operation, robots have a high chance of colliding with humans, which may result in serious injury. Thus, many solutions were proposed to ensure collision safety, and among them, collision detection algorithms are regarded as one of the most practical solutions. They allow a robot to quickly detect a collision so that the robot can perform a proper reaction to minimize the impact. However, conventional collision detection algorithms required the precise model of a robot, which is difficult to obtain and is subjected to change. Also, expensive sensors, such as torque sensors, are often required. In this study, we propose a novel collision detection algorithm which only requires motor encoders. It detects collisions by monitoring the high-pass filtered version of the velocity error. The proposed algorithm can be easily implemented to any robots, and its performance was verified through various tests.

• The Journal of Korea Robotics Society
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• v.15 no.3
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• pp.233-239
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• 2020

The aims of this paper is to develop a modular agricultural robot and its autonomous driving algorithm that can be used in field farming. Actually, it is difficult to develop a controller for autonomous agricultural robot that transforming their dynamic characteristics by installation of machine modules. So we develop for the model based control algorithm of rotary machine connected to agricultural robot. Autonomous control algorithm of agricultural robot consists of the path control, velocity control, orientation control. To verify the developed algorithm, we used to analytical techniques that have the advantage of reducing development time and risks. The model is formulated based on the multibody dynamics methods for high accuracy. Their model parameters get from the design parameter and real constructed data. Then we developed the co-simulation that is combined between the multibody dynamics model and control model using the ADAMS and Matlab simulink programs. Using the developed model, we carried out various dynamics simulation in the several rotation speed of blades.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.1028-1032
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• 1988

The purpose of this paper is the development of a fully integrated simulation package for industrial robot. The simulation package consists of kinematics, dynamics, and control. The kinematics contains trajectory plans and inverse kinematics. The dynamics combines manipulator dynamics and actuator dynamics including the effect of payloads and viscous frictions. The control is a hardware oriented scheme which contains position controller, velocity controller, current controller, and PWM generator. Thus, the simulation package can be used not only for theoretical purposes but also for development purposes in industry. Using this package, the characteristics and performances of the SCARA robot, which has been developed in GSIS, are investigated.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.3
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• pp.157-166
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• 2015

In this paper, we proposed a new robust control scheme to implement stable control of robot manipulators including nonlinear perameters The proposed robust controller is composed of a nonlinear controller and linear compemsation controller. It shows a good robust performance in reaching mode which does not possess invariance property. Thus, the proposed nonlinear controller showed a good robust performance in the whole region, It was illustrated that the proposed control showed a good transient response and trajectory tracking performance for robot manipulator with four joint by experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.577-582
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• 2015

This paper proposes an efficient detection of absolute position of a robot joint using two incremental encoders. We considers a robot joint comprising a motor, a reducer, two encoders, and a motor drive. An incremental(first) encoder provides motor's rotor position or input position of reducer while another incremental(second) encoder does output position of the reducer. A table is made where the relationship between the first and the second encoder counts is recorded. The key point is placed where the table is constructed: when a pulse occurs in the second encoder, there exists a corresponding unique count value of the first encoder. The absolute position is detected using the table by searching the second encoder position corresponding to the first encoder count value when a pulse occurs in the second encoder. The proposed method needs a small rotation, as just one second encoder's pulse angle, for the initial absolute position detection.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.129-138
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• 2015

This study describe a new method to control posture and velocity for a wheeled mobile robot using visual feedback control method with a position based visual feedback. To slove the problem of vibration phenomena which were shown in the previous researches using a simple switching function based on a threshold, the proposed visual servo control law introduces the fusion function based on a blending function. The chattering problem and rapid motion of the mobile robot can be eliminated. And we consider the nonlinearity of the wheeled mobile robot unlike the previous visual servo control laws using linear control methods to improve the performances of the visual servo control law. The proposed posture control law using visual servoing is verified by a theoretical analysis and simulation and experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.932-935
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• 2005

Three dimensional laser welding technology for light car body is studied. A robot, a seam tracking system and 4kW CW Nd:YAG laser are used for three dimensional robot laser welding system. The Laser system is used 4kW Nd:YAG laser(HL4006D) of Trumpf and the Robot system is used IRB6400R of ABB. The Seam tracking system is SMRT-20LS of ServoRobot. The welding joint of steel plate are butt and lap joint. The 3-D welding for Non-linear Tailored blank is performed after the observation experiments of bead on plate. Finally, the welding process for non-linear tailored blank and front side member is developed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1780-1781
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• 2011

There have been numerous studies on application of robots to in-pipe inspection system. In this thesis, a mobile robot that can move through elbows and vertical pipes having diameter 100mm is developed. Defect detection technology for locating wall-thinnings, corrosions and foreign materials is developed for high temperature and pressure pipings in thermal power plants, utilizing laser sensors installed on the robot. Actual defect detection performance is evaluated with application of the developed robot system to a mock-up pipings.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.658-663
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• 2005

This paper presents the steering control algorithm of a locomotion robot using a quaternion. The locomotion robot is to be moved on an irregular floor that can inevitably result in the errors of both position and orientation. Especially the orientation error should be compensated every work in order to adjust the misaligned values of current orientation to those commanded values. In this paper, we propose a new steering control algorithm between the two values by using a quaternion with spherical cubic interpolation. The proposed algorithm is shown to be effective in terms of vibration when compared to a conventional simple compensation without interpolation, by using $MATLAB^{(R)}$ and $VisualNastran4D^{(R)}$.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.4
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• pp.224-230
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• 2015

In this paper, it is presented a learning controller for repetitive walking control of biped walking robot. We propose the iterative learning control algorithm which can learn periodic nonlinear load change ocuured due to the walking period through the intelligent control, not calculating the complex dynamics of walking robot. The learning control scheme consists of a feedforward learning rule and linear feedback control input for stabilization of learning system. The feasibility of intelligent control to biped robotic motion is shown via dynamic simulation with 25-DOF biped walking robot.