• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.498-505
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• 2000

Performance of a hydraulic system is influenced by its working temperature. Therefore, it is very important to make the system perform uniformly in an entire range of the working temperature. In this study a simulation of a hydraulic control system for the powershift transmission of tractors was conducted and the effect of the temperature was investigated in terms of design conditions of the system. Results of the simulation are as follows. The hydraulic control system with a spring accumulator was found to be more convenient to control the shifting time than that with a gas accumulator. By returning the oil from the clutches to the system through a path between the filter and pump, the time delay due to the pressure difference between the low and high temperatures could be reduced. Therefore, it was recommended that the hydraulic control system for the powershift transmission of tractors must be equipped with a spring accumulator and a circuit to return oil from the clutches to the system through a path between the filter and pump.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.133-136
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• 1996

The nozzle dam task is essentially needed to maintain and repair nuclear power plants. For this task, an 8-dof redundant robot is studied with a local path-planning method[l] which is effective to find the optimal joint path in the constrained environment. In this paper, the method[l] is improved practically with the weight matrix and efficient algorithm to find working set. The effectiveness of the proposed method is demonstrated by simulation and animation.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.96-104
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• 2006

We propose a path planning method to improve the productivity of AOI (automated optical inspection) machines in PCB (printed circuit board) assembly lines. The path-planning problem is the optimization problem of finding inspection clusters and the visiting sequence of cameras to minimize the overall working time. A unified method is newly proposed to determine the inspection clusters and visiting sequence simultaneously. We apply a hybrid genetic algorithm to solve the highly complicated optimization problem. Comparative simulation results are presented to verify the usefulness of the proposed method.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.201-210
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• 2019

This paper proposes the AMCS(Agricultural Machine Control System that distinguishes farms using satellite photos or drone photos of farms and controls the self-driving and operation of farm drones and tractors. The AMCS consists of the LSM(Local Server Module) which separates farm boundaries from sensor data and video image of drones and tractors, reads remote control commands from the main server, and then delivers remote control commands within the management area through the link with drones and tractor sprinklers and the PSM that sets a path for drones and tractors to move from the farm to the farm and to handle work at low cost and high efficiency inside the farm. As a result of AMCS performance analysis proposed in this paper, the PSM showed a performance improvement of about 100% over Dijkstra algorithm when setting the path from external starting point to the farm and a higher working efficiency about 13% than the existing path when setting the path inside the farm. Therefore, the PSM can control tractors and drones more efficiently than conventional methods.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.9
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• pp.816-821
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• 2005

The remote operation of $4\~5$ cranes for container loading/unloading at a port by one operator will dramatically improve loading/unloading efficiency through productivity increase, cost reduction, and so on. This study develops a remote crane control system for container loading/unloading yard cranes. First, a wireless video and audio system to transmit views and sounds of the working field is designed by using 3 web cameras and a microphone. Next, a RSVP-based multi-path reservation method is presented with a view to improving the quality of service in the communication network for remote control. Simulation results show that a RSVP-based multi-path reservation can enhance the reservation success rate in the TCP/IP network.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.2
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• pp.168-177
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• 2008

Path finding is a key element in the navigation of a mobile robot. To find a path, robot should know their position exactly, since the position error exposes a robot to many dangerous conditions. It could make a robot move to a wrong direction so that it may have damage by collision by the surrounding obstacles. We propose a method obtaining an accurate robot position. The localization of a mobile robot in its working environment performs by using a vision system and Virtual Reality Modeling Language(VRML). The robot identifies landmarks located in the environment. An image processing and neural network pattern matching techniques have been applied to find location of the robot. After the self-positioning procedure, the 2-D scene of the vision is overlaid onto a VRML scene. This paper describes how to realize the self-positioning, and shows the overlay between the 2-D and VRML scenes. The suggested method defines a robot's path successfully. An experiment using the suggested algorithm apply to a mobile robot has been performed and the result shows a good path tracking.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.4
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• pp.379-386
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• 2003

The goal of this research is to develop a Heel/Side Laster and control GUI(Graphic User Interface) for adaptive manufacturing. For this purpose, we have analyzed the working sequences of heel/side laster, and developed a control program that will facilitate the machineries with functions that are suitable for adaptive manufacturing. We also made it possible to modify the gluing path with simple manipulation of CAD data. By providing a user-friendly GUI, we made it possible for unskilled workers use the system without difficulty. In addition, we have developed a flexible environment where the already available CAD data can be modified and saved with ease. Automatic feeding and path control algorithms for thermoplastic cement were also implemented. By using the Heel/Side Laster for adaptive manufacturing, we are able to achieve increased productivity and work efficiency while improving the quality of the product with self-diagnosis and fine adjustment function.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.47-51
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• 1990

In the system of contemporary factory, the frequent generation of robot program reduces the efficiency of robot working. In this study, the SIOPS (Soldering and Insertion Offline Programming System) that automatically generates the robot program is presented. The system can change the parameter about soldering and insertion interactively and generate the robot tool path.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.7
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• pp.643-648
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• 2004

Most of shoes manufacturing processes are not yet automated, which puts restrictions on the increase of productivity. Among them, adhesive application processes particularly are holding the most workers and working hours. In addition, its working conditions are very poor due to the toxicity of adhesive agents. In case of automating adhesive application processes by using robots, the robot teaching by playback is difficult to produce high productivity because the kinds of shoes to be taught mount up to several thousands. Therefore, it is essential to generate the robot working paths automatically according to the kind, the size, and the right and left of shoes, and also to teach them to the robot automatically. This study deals with automated adhesive spraying to shoe outsoles and uppers by using a robot, and develops the program to generate three-dimensional robot working paths off-line based on CAD data. First, the three-dimensional data of an outsole outline or an upper profiling line are extracted from the two-dimensional CAD drawing file or the three-dimensional scanner. Next, based on the extracted data and the nozzle conditions for adhesive spraying, a robot working path is generated automatically. This research work is the core in automating adhesive spraying processes, and will do much for increasing productivity of shoes manufacturing.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.2
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• pp.83-88
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• 2016

In this paper, a design method for a logistics transportation robot based on a modular conveyor rack and path planning considering the environment of a logistics center is proposed. The driving part of the logistics transportation robot is designed and the working method of lifter for the transportation function is explained. The design of the modular conveyor rack is also described and an algorithm for a logistics transportation robot using a modular conveyor rack is suggested. The $A^*$ algorithm is improved by using the concept of rotation cost and the initial state of the transportation robot's characteristics. We experimented with a four-step transportation algorithm for a logistics transportation robot using a modular conveyor rack and showed that the proposed method can be used successfully in a logistics center. In addition, we verified the effectiveness of the improved $A^*$ algorithm considering the rotation cost and the initial state of the robot.