• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.14-19
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• 2000

Recent requirements for the fast and accurate motion in industrial robot manipulator need more advanced control techniques. To satisfy the requirements, importance of the force control is being continuously increased and the expensive force sensor is usually 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 2 DOF robots and environment. The contact force estimation system is developed based on the static and dynamic models of 2 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 Institute of Control, Robotics and Systems
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• v.11 no.2
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• pp.103-108
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• 2005

Loading/Unloading task in the real industry is performed by crane, but most of the loading/unloading task with the weight of 5kg∼30kg is done by human workers and this kind of work causes industrial disaster of workers. Therefore it is necessary to develop low cost loading/unloading manipulator system to prevent this kind of industrial accidents. This paper is concerned with the design and fabrication of 2 axis pneumatic manipulators using on/off solenoid valves and accurate position control without respect to the external load and low damping in the pneumatic rotary actuator. To overcome the change of external load, switching of control parameter using LVQNN (Learning Vector Quantization Neural Network) is newly applied, which estimates the external loads in the pneumatic cylinder. As an underlying controller, a state feedback controller using position, velocity and acceleration is applied to the switching control system. The effectiveness of the proposed control algorithms are demonstrated through experiments of pneumatic cylinder with various loads.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.5
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• pp.259-267
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• 2019

This paper proposes a structure of a variable impedance control system based on sensor-less external force estimator of industrial manipulators for cyber physical production systems (CPPS). To implement CPPS, a feedback system is constructed by using the robot operating system (ROS) and an external force estimator which is designed to measure the external force applied to the manipulator without a force sensor. Based on the robot dynamics, the robot-human cooperating system for the cyber physics production system is implemented through a controller that changes the impedance characteristics of the manipulator according to the situation using the external force estimator. Simulation and experimental results verify the effectiveness of the proposed control system.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10a
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• pp.882-885
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• 1987

The path of an industrial manipulator in a crowded workspace generally consists of 8 set of Cartesian straight line path connecting a set of two adjacent points. To achieve the Cartesian straight line path is, however, a nontrivial task and an alternative approach is to place enough intermediate points along a desired path and linearly interpolate between these points in the joint space. A method is developed that determines the subtravelling- and the transition-time such that the total travelling time for this path is minimized subject to the maximum joint velocities and accelerations constraint. The method is based on the application of nonlinear programming technique, i.e., FTM (Flexible Tolerance Method). These results are simulated on a digital computer using a six-joint revolute manipulator to show their applications.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1396-1401
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• 2004

In recent years, robot has been used widely in industrial field and has been expanded as a result of continous research and development for high-speed and miniaturization. The goal of this paper is to design the special serial manipulator through the understanding of the structure, mobility, and analysis of serial manipulator. Thereafter we control the position and orientation of end-effector with respect to time. In general, a structure of industrial robot consists of several links connected in series by various types of joints. Typically revolute and prismatic joints. The movement of these joints is determined in inverse kinematic analysis. Compared to the complicated structure of parallel and hybrid robot, open loop system retains the characteristic that each link is independent and is controlled easily by AC servomotor that is used to place the robot end-effector toward the accurate point with the desired speed and power while it is operated by position control algorithm. The robot end-effector should trace the given trajectory within the appropriate time. The trajectory of 3D end-effector model made by OpenGL can be displayed on the monitor program simultaneously

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.163-168
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• 2001

A manipulator for test-cup attachment modules, which was a part of a robot milking system, was developed to reduce cost and labor for cow milking processing. A Cartesian coordinate manipulator was designed for the milking process, because it was quite flexible and can be constructed more economically than any other configuration. The manipulator was made use of DC motors, screws for power transmission, a RS422 interface system for the transmission of coordinate values and a one-chip microprocessor, 89C52. Performance tests of the manipulator were conducted to measure experimentally the precision of all axes. Some of the results are as follows. 1. The Cartesian coordinate manipulator was designed and built. Dimension of the three perpendicular axes (X, Y, and Z) and one arm’s axis(W) to pick up and transfer the modules were 700㎜$\times$450㎜$\times$550㎜$\times$650㎜. The arm’s axis moved the teat-cup attachment module, which attached four teat-cup to four teats, detached four teat-cup from four teats, was designed and manufactured by using CAD, CAM and CNC. 3. After 10 replications of exercising the manipulator, mean precision values(positioning error) of X, Y, Z axes wee 0.48㎜, 0.20㎜, 0.19㎜, respectively. Therefore, we conclude the axes to have a precision better than 0.5㎜, had no problem to operate correctly the milking manipulator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.3023-3031
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• 2013

In this paper, we propose a robot control data generation system applying context aware mechanism in order to control the robot manipulator which automatically sorts parcels. The context aware mechanism generates intelligent information to control a robot using context data such as the parcel shape, weight, location and barcodes. The proposed system collects context data of the parcel and generates robot control data to pick up and drop parcels. Then a robot manipulator, which receives control data of picking-up and dropping, processes the automated sorting of parcels according to delivery persons and delivery routes. It will contribute not only to save much time and cost but also to reduce the industrial accidents.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.451-457
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• 2015

In this paper, we consider the observer design problem that truly reflects the nonlinear stiffness of the manipulators. The two key ideas of our design are that (a) estimation error dynamics of the manipulator equipped with accelerometer dose not dependent on nonlinearities at the link part, when the measured signals are the motor position and the output of the accelerometer and (b) the nonlinear stiffness is indeed a Lipschitz function. In order to effectively compensate the nonlinear stiffness, the gain of the proposed observer is carefully chosen from the ARE(algebraic Riccati equations) which depend on Lipschitz constant. Comparative simulation result verifies the effectiveness of the proposed solution.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1631-1634
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• 1997

Since surgery is usually a difficult task because of physiological tremor, eye strain, and tremor, contagious and radioactive hazard, it is necessary to develop micro-surgery telerobotic system using improved tools suitable for their specific tasks. Nowadays the growth of interest on microsurgery and medical applications of robotics has been so rapid. But the medical robots are only practical applications of the industrial robots. This paper identifies five general areas of advanced microsurgery based on the current technological background and expertise, and analyzes the motion, tool and accuracy with respect to microsurgery task, and proposed the criteria to evaluate micro-surgical manipulator. The analysis of microusrgery can be heplful to clarify some basic concept and design of micro-surgical manipulators. With these data we will alos propose an efficient in-parallel-platform manipulator having special kinematic structrue structure suitable for microsurgery.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.1
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• pp.37-43
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• 2010

In this paper, we implement that hollow type joint using two more than general motor and design for compact structure embedded electronic parts in the development of 7 degree of freedom manipulator. We propose a method to overcome risk and the limit of operating radius which are point out as a limit of previous industrial robot. and also propose to more efficient and stable manipulator implement method.