• Journal of Korean Institute of Industrial Engineers
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• v.42 no.3
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• pp.173-181
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• 2016

This paper deals with the single-hoist and multiple-products scheduling problem. Although a mixed integer linear programming model for the problem was developed earlier, a branch-and-bound based heuristic algorithm is proposed in this paper to solve the big-size problems in real situation. The algorithm is capable of handling problems incorporating different product types, jobs in the process, and tank capacities. Using a small example problem the procedure of the heuristic algorithm is explained. To assess the performance of the heuristic we generate a bigger example problem and compare the results of the algorithm proposed in this paper with the optimal solutions derived from the mathematical model of earlier research. The comparison shows that the heuristic has very good performance and the computation time is sufficiently short to use the algorithm in real situation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.281-286
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• 2002

An existent hoist drive system is using each different drive equipment in control of Hoisting, traveling(T/L), traversing(T/S) driving, so there are much energy losses because of excessive weight. Also, power circuits are using relay contact, so working environment are frequent secession accident etc.. by shock on unfavorable condition, and there is danger of safety accident, maintenance has frequent problem and so on. To solve these problem, it is integrated each driving power supply in drive system for hoist control and drive, utility power supply etc.. by single device in this research. The power circuit is consisted of non-contact circuit applying to bidirectional voltage controller circuit using thyristor that is power semiconductor switching device

• The Journal of Korea Robotics Society
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• v.18 no.4
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• pp.403-408
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• 2023

In this paper, we introduce the results of the development of a care robot for the safe lifting and transportation of bedridden patients with difficulty moving by themselves, especially, in medical facilities. The purpose of the developed patient transfer robot is to improve the convenience of care givers and enhance the safety and comfort of care recipients by facilitating patient lifting and patient transfer tasks by applying robot technology. In order to implement the lifting function, a hoist was designed and developed, and a sway control and rollover warning system were included in the hoist module as product differentiators. In addition, in terms of implementing the transfer function, an omnidirectional movement mechanism to improve operability in confined spaces and an active safety system to prevent collisions were developed. The function of the developed patient transfer robot was verified through performance evaluation by an authorized testing agency.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.128-135
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• 2005

Overhead crane systems consist of trolley, girder, rope, objects, trolley motor, girder motor, and hoist motor. The dynamic system of these systems becomes a nonlinear state equations. These equations are obtained by the nonlinear equations of motion which are derived from transfer functions of driving motors and equations of motion for objects. From these state equations, Lyapunov functions of overhead crane systems are derived from integral method. These functions secure stability of autonomous overhead crane systems. Also constraint equations of driving motors of trolley, girder, and hoist are derived from these functions. From the results of computer simulation, it is founded that overhead crane systems is secure.

• Journal of Ocean Engineering and Technology
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• v.19 no.5 s.66
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• pp.58-64
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• 2005

In this paper, a feedback linearizing anti-sway control law, using a 2-D model for container cranes, is investigated. The equations of motion are first derived from Lagrange's equation. Then, by substituting the sway dynamics into the trolley dynamics, a reduction of variables from three (trolley, hoist, sway) to two (trolley, hoist) is pursued. The anti-sway control law is designed based on the Lyapunov stability theorem. The proposed control law guarantees the uniform asymptotic stability of the closed-loop system. The simulation results of the derived control law, using MATLAB/Simulink, are compared with those of the sliding mode control law, noted in previous literature. Also, experimental results using a 3-D pilot crane are provided.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.461-470
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• 2004

As the semiconductor industrials change 200㎜-sized semiconductor wafer production process to 300㎜-sized one, it requires to develop the software for monitoring and simulating the robot which transfers a 300㎜-sized semiconductor wafer. Because such a software don't run at standalone but communicate MCS(Material Control System) and Its subsystem a robot, its architecture is very complex. Therefore, in order to develop such a software systematically, we must utilize an object-oriented development methodology. UML. This paper presents an UML process application developing the software for monitoring and simulating the robot which transfers a semiconductor wafer on the production process.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.7
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• pp.205-214
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• 2021

For smart manufacturing, most semiconductor sites utilize automated material handling systems(AMHS). As one of the AMHSs, the OHT control system(OCS) manages overhead hoist transports(OHT) that move along rails installed on the ceiling. This paper proposes a real-time scheduling system to efficiently allocate and control the OHTs in semiconductor logistics processes. The proposed system, as an independent subsystem within the OCS, is interconnected with the main subsystem of the OCS, so that it can be easily modified without the effect of other systems. To develop the system, we first identify the functional requirements of the semiconductor logistics process and classify several types of control scenarios of the OHTs. Next, based on SEMI(Semiconductor Equipment and Materials International) standard, we design sequence diagrams and interface messages between the subsystems. The developed system is interoperated with the OCS main subsystem and the database in real time and performs two major roles: 1) OHT dispatching and 2) pathfinding. Six integrated tests were carried out to verify the functions of the developed system. The system was normally operated on six basic scenarios and two exception scenarios and we proved that it is suitable for the mission planning of the OHTs.

• Journal of the Korean Society of Safety
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• v.12 no.1
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• pp.129-132
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• 1997

The effectiveness of an ensuring the facility safety depends on the ability to find abnormal part(s) and remove that part(s). This requires the knowledge of that machine and ability to recover that machine. In this paper, it is discribed how to design the fuzzy based self organizing neural network expert system in order to find syptom source(s).

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1250-1253
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• 1993

The fuzzy control theory is applied to control a container crane, which is a very complicated system and controled manually by experts. As reference velocities of trolley and hoist of the container crane, we use those decided by experts, and express them by fuzzy model. We control the crane to follow the reference velocities by using fuzzy controllers. The fuzzy controllers are designed on the container crane. We made a model container crane and applied the suggested method to it

• Journal of Korean Port Research
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• v.12 no.1
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• pp.113-118
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• 1998

The Container crane is mainly used in the harbor. But in spite of this wide use, it is a fact that there are still areas for automation, concerning the operator and the control system. If the encoding function is enhanced, then control effect can be increased to some extent. Since the distance from the hoist to the trolley cam be measured, the moving distance from the loading and unloading can be minimized. If this is applied to the real system, hazard elements can be eliminated and in given time since more unloading can be done, congestion can be reduced.