• The Journal of Korea Robotics Society
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• v.13 no.1
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• pp.55-62
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• 2018

In this paper, a method for estimation of external force on an end-effector using joint torque sensor is proposed. The method is based on portion of measure torque caused by external force. Due to noise in the torque measurement data from the torque sensor, a recursive least-square estimation algorithm is used to ensure a smoother estimation of the external force data. However it is inevitable to create a delay for the sensor to detect the external force. In order to reduce the delay, modified recursive least-square is proposed. The performance of the proposed estimation method is evaluated in an experiment on a developed six-degree-of-freedom robot. By using NI DAQ device and Labview, the robot control, data acquisition and The experimental results output are processed in real time. By using proposed modified RLS, the delay to estimate the external force with the RLS is reduced by 54.9%. As an experimental result, the difference of the actual external force and the estimated external force is 4.11% with an included angle of $5.04^{\circ}$ while in dynamic state. This result shows that this method allows joint torque sensors to be used instead of commonly used external sensory system such as F/T sensors.

• Nuclear Engineering and Technology
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• v.27 no.5
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• pp.661-669
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• 1995

A mobile robot, named KAEROT, has been developed for inspection and maintenance operations in nuclear facilities. The main feature of locomotion system is the planetary wheel assembly with small wheels. This mechanism has been designed to be able to go over the stairs and obstacles with stability. This paper presents the inverse kinematic solution that is to be operated by remote control. The automatic stair climbing algorithm is also proposed. The. proposed algorithms generates the moving pathes of small wheels and calculates the angular velocity of 3 actuation wheels. The results of simulations and experiments are given for KAEROT peformed on the irregular stairs in laboratory. It is shown that the proposed algorithm provides the lower inclination angle of the robot body and increases its stability during navigation.

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.215-226
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• 2010

Since product design strongly depends on the experience and ability of the designers, and a long lead time is required for the product design stage, introducing a support system related to this experience and ability is an effective technique to reduce the lead time. In this paper, an information system is developed to support the development of engineering mechanisms with the evaluation of the assembly process on the basis of the abstract functions required for new products. The developed system is based on a database system involving the following data structure: (1) a hierarchical structure related to information about the product functions, (2) the relationship between the parts and engineering functions and/or mechanisms of products, and (3) the relationship between the parts and manufacturing characteristics. The system stores the relationships between the product functions, structure of parts, and assembly characteristics. This information can then be interactively retrieved using the data structure described in (1), (2), and (3). A procedure for designing new products is proposed that involves using the information about existing products. This paper presents the characteristics of the proposed procedure and the developed information system. In addition, a case study of the redesign of a simple structured robot by using the proposed procedure is discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.61.5-61
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• 2001

The laser tracking system(LTS) presents the most promising technique for dynamic position measurement of industrial robots. This system combine the advantage of high accuracy with a contactless measurement technique. It is the measurement system of position in three dimensions using distance data obtained by laser interferometer and real time angle by tracking mirror assembly. After measuring the tracking error of the beam projected on the center of retroreflector in robot end effector, this system tracks the end effector continuously by adjusting tracking mirror angle to minimize this error ...

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.813-816
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• 1991

Direct-drive SCARA-type industrial robots are increasingly used in the assembly process of small mechanical parts as well as electronic components, which uses direct-drive (DD) motors instead of reduction gear-type conventional motors for the actuators of manipulator arms. There are many advantages in using DD motors for robots, such as no backlash, low friction, high mechanical stiffness capability for fast and precise arm control, and high repeatability of positioning. However, there exist a number of difficulties which must be overcome to ensure proper construction and operation; increasing effects of load veriation and nonlinear and coupling dynamics, severe vibration caused by resonance of the manipulator components and low mechanical damping, etc. In order to handle these difficulties, lots of efforts have been made such as reduction of the arm inertia and elimination of the resonance, Performance evaluation of a recently developed, domestic DD robot shows that it works excellently compared with conventional robots. It, however, requires proved reliability and price competitiveness against its foreign counterparts.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.11
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• pp.796-803
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• 1988

In this paper, the design method, design techniques and structure of a language for a SCARA type industrial robot, are presented. The proposed new language is modular and expandable using the C programming language and the 8086 assembly language. It is composed of monitor mode which controls the main flow of the programs, editing mode which generates, corrects and edits the programs, execution mode which executes the generated programs, I/O mode which interacts with the external devices, and teach mode. The developed language is implemented on the robot controller to verify its performance.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.3
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• pp.173-180
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• 2015

In this paper, we propose a new precise control technology of robotic gripper for assembling and handling of part. When a robot manipulator interacts mechanically with its environment to perform tasks such as assembly or edge-finishing, the end-effector is thereby constrained by the environment. Therefore grasping force control is very important, since it increases safety due to monitoring of contact force. A comparison of various force control architecture is reported. Different force control methods can often be configured to achieve similar results for a given task, and the choice of control algorithm depends strongly on the application or on the characteristics of a particular robot. In the research, the adjustable gripping force can be controlled and improved the accuracy using the artificial intelligence techniques.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.417-422
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• 1990

For the robot manipulator in performing precision task, it is indispensable that the robot utilize the various sensors for intelligence. This paper presents the development and implementation of an integrated control system for the control of robotic manipulator, a feeder, a conveyor belt system, force/torque sensor system, and a photo sensor system. Micro controller board was constructed for hierarchical control of the system. To set up the program interactively, a user can make use of the software which includes the full-down menu and a dialog box. The user can make progress the program quickly and easily by a mouse. The related software was written in C and assembly languages.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1757-1762
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• 2003

For coping with various ship types easily, welding automation using CAD/CAM is demanded and and developed. In this paper we propose a dedicated CAM system which generates MACRO files to control robot manipulators. The paper contains CAD interface, virtual simulation, macro generation and job schedulling. At first, it defines and extracts weldline from CAD data, and generates proper MACRO programs. And it obtains optimum job schedules. This system removes the manual work, and consequently reduces the overall lead time. And it reduces costs and time for developing robot welding programs. This can be expanded to virtual factory simulation technology. Moreover, it is possible to apply this system for automation of Cutting and Painting

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.34-41
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• 1996

This work deals with finding a suitable position correction algorithm of industrial robot based on measuring particular points, which calculates two dimensional correction quantities and the must allow visually acceptable door-chassis assembly task. Three optimizing algorithms corresponding to three differ- ent error based performance indices are compared and selected to the best one, in terms of the predefined total uniformity, line uniformity and computational time. The selected algorithm(Total Error Minimization) is implemented for a simple door-chassis model to show its effectiveness.