• Journal of Welding and Joining
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• v.16 no.3
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• pp.102-110
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• 1998

The horizontal fillet welding is prevalently used in heavy and ship building industries to fabricate the large scale structures. A deep understanding of the horizontal fillet welding process is restricted, because the phenomena occurring in welding are very complex and highly non-linear characteristics. To achieve the satisfactory weld bead geometry in robot welding system, the seam tracking algorithm should be reliable. The number of seam tracker was developed for arc welding automation by now. Among these seam tracker, the arc sensor is prevalently used in industrial robot welding system because of its low cost and flexibility. However, the accuracy of arc sensor would be decreased due to the electrical noise and metal transfer. In this study, the signal processing algorithm based on the neural network was implemented to enhance the reliability of measured welding current signals. Moreover, the seam tracking algorithm in conjunction with the signal processing algorithm was implemented to trace the center of weld line. It was revealed that the neural network could be effectively used to predict the welding current signal at the end of weaving.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.345-350
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• 2021

The maintenance of sensor networks, installed in a wide area has been an issue for a long time. In order to solve this problem, studies to supply energy to a sensor network using a robot has been carried out by several researchers. In this study, for a sensor network consisting of power nodes supplied with energy by multiple robots and sensor nodes around them, we propose a method of allocating a work area using a modified k-means algorithm so that the robots move the minimum distance. Through the simulation study using the energy transfer rate of the robot as a variable, it is shown that nodes of each allocated area can maintain survival, and the validity of the proposed modified k-means algorithm is verified.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.850-858
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• 1993

Germinatin and early growth of tobacco seedlings in trays containing many cells is increasing in popularity . Since 100 % germination is not likely , a major problem is to locate and replace the content of those cells which contain either no seedling or a stunted seedling with a plug containing a viable seedling. Empty cells and seedlings of poor quality take up valuable space in a greenhouse. They may also cause difficulty when transplanting seedlings into the field. Robotic technology, including the implementation of computer vision, appears to be an attractive alternative to the use of manual labor for accomplishing this task. Operating AGBOT, short for Agricultural ROBOT, involved four steps : (1) capturing the image, (2) processing the image, (3) moving the manipulator, (4) working the gripper. This research seedlings within a cell-grown environment. the configuration of the cell-grown seedling environment dictated the design of a Cartesian robot suitable for working ov r a flat plane. Experiments of AGBOT performance in transferring large seedlings produced trays which were more than 98% survived one week after transfer. In general , the system generated much better than expected.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.9
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• pp.36-44
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• 1993

In the development of a high speed and light weight manipulator, it is necessary to consider the flexibility of a robotic arm. The infinite dynamics must be analyzed to obtain the finite mode modeling to achieve the feasible controller design of the robotic arm. The modeling procedures of the flexible robot arm, and natural frequencies and mode shapes by the constrained and unconstrained mode method are illustrated. The transfer function of the robot arm with a payload is also shown. The controller is designed by the pole assignment and optimal control theory to compensate for the unmodelled dynamic effects to the low order system. Also, the pole assignment method involving the harmonic vibration mode is presented through computer simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1110-1113
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• 1995

This study presents the new method which can transfer the expert's skill to deburring robot through neural network. The expert's skill is expressed as associationmapping between the characteristics of the burr and human expert's action. Under the fundamental idea that the state of the deburring processcan be extracted via the visual sense of the human,we employ vision system for the perception and identification of the changing burr. Form the demonstration of human experts, force data are measured. Finally the characteristics of the burr and coressponding force are associated by the neural network which is trained through many demonstrations. The proposed method is verified in the deburring process of welding burr.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.821-825
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• 1991

This paper presents an architecture and control logic of a Flexible Manufacturing Cell (FMC) which is one of the important elements under Computer Integrated Manufacturing (CIM) environment. To implement FMC, it is very important to develop a software which can control and monitor the overall system in an integrated environment. Our primary concern in this research is not to develop individual systems, but to integrate them in the hierarchical control level. Progress on the research of integrating CAD/CAM, Process Planning, Off-line Robot Programming and Simulation module into FMC control system is reported. FMC hardware system used here has an Automated Storage & Retrieval System (AS/RS), a conveyor system, a transfer robot, a CNC milling machine, a bar-code system, and an IBM PC/AT as Cell Control System (CCS). In order to demonstrate the operational result, the name plates, text-carved aluminium plates, are manufactured by this system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.229-233
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• 2001

In this paper, we propose a remote controller for robot manipulator using local area network(LAN) and internet. To do this, we develope a server-client system as used in the network field. The client system is in any computer in remote place for the user to log-in the server and manage the remote factory. the server system is a computer which controls the manipulator and waits for a access from client. The server system consists of several control algorithms which is needed to drive the manipulator and networking system to transfer images that shows states of the work place, and to receive a Tmp data to run the manipulator. The client system consists of 3D(dimension) graphic user interface for teaching and off-line task like simulation, external hardware interface which makes it easier for the user to teach. Using this server-client system, the user who is on remote place can edit the work schedule of manipulator, then run the machine after it is transferred and monitor the results of the task.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.4
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• pp.111-117
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• 1998

In order to increase productivity of an assembly system composed of multiple robots along a conveyer line, an efficient sequence planning is necessary because the assembly time is dependent upon the assembly sequence. In this paper, a two-robot assembly system is considered in which two robots operate simultaneously and transfer parts from the part feeders to the workpiece on the conveyer one by one. In this case, the distance from the feeder to the workpiece varies with time because the workpiece moves at a constant speed on the conveyer. Hence, the sequence programming is not a trivial problem. Also, the two robots may interfere with each other kinematically and dynamically due to the simultaneous operation, so the sequence should be programmed to avoid the interferences. In this paper, the task sequence optimization problem is formulated and is solved by employing the simulated annealing which has been shown to be effective for solving large combinatorial optimizations.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2415-2417
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• 2002

In this paper, we discuss about the real-time distributed system for the control of to motors using uCOS-II kernel. Real-time kernel needs to process the tasks for two motors in desired time to synchronize motion. We used both semaphore and message mail box for synchronization. In the previous study, we used step motors for the actuator of two axes robot, but could not draw a clear line because of motor resolution and synchronizing step pulse. To resolve the problem we rebuilt the transfer robot with DC motors and the dedicated position servor which had built in out lab. Moreover we developed the PC based graphic user interface for generating planar drawing image control. Experimental results also presented to show the proposed control system is useful.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.650-655
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• 2016

In this paper, a novel RLS-based DOB (Recursive Least Squares Disturbance Observer) scheme is proposed to improve the performance of DOB for nominal model identification. A nominal model can be generally assumed to be a second order system in the form of a proper transfer function of an ARMA (Autoregressive Moving Average) model. The RLS algorithm for the model identification is proposed in association with DOB. Experimental studies of the balancing control of a one-wheel robot are conducted to demonstrate the feasibility of the proposed method. The performances between the conventional DOB scheme and the proposed scheme are compared.