• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.53-60
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• 2001

This paper presents a position control of a platform at the seaport cargo handling system. After brief description of the operating principles of the cargo handling system, the governing equation of the moving platform is derived. The equation is described in the state space model, and a robust H$_{\infty}$ controller to achieve position tracking of the moving platform. which can carry 200ton of containers, is formulated. In the synthesis of the controller, the weight of the container is treated as uncertain parameter. Both regulating and tracking control responses are analyzed for the loading and unloading procedures of the proposed automatic cargo handling system.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.61-69
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• 2020

As post-harvest processes of onions are carried by a 20 kg-net package which results in high-cost and low-efficiency, especially, the insufficient drying and physical damage of onions after harvesting leads to a huge second loss in storage, we had developed a low-cost, high-efficiency post-harvest bulk handling machinery system by collecting onions on a farm using ton-bags, drying with forced air circulation, and sorting/packaging. The post-harvest bulk handling machinery system consisted of 6 devices, and this study designed an automatic feed hopper with a feeding rate control device, an inclined belt conveyor with a two-step chute, and an automatic pallet unloading device for feeding onions into the sorting/packing line. This study also analyzed the performance and control of the total system. The device had 1-ton handling capacity, but the operational condition was set to increase the capacity. The three-step filling method of pallet by the velocity control of the inclined belt conveyor was applied in the post-harvest bulk handling machinery system for the prevention of physical damage. If one worker was set to operate the total system, the time required to complete one palletized load was approximately 5 minutes and 5 seconds. The calculated daily handling capacity was approximately 94 tons, when the daily actual working time was 8 hours. When the developed system was applied to the managerial size of 2,000 ton, the processing cost per ton of the system was decreased by 19.5%, compared with the existing 20 kg-net package-based handling. The developed post-harvest bulk handling machinery system would be a good substitute for the rapid decline and aging of rural labor.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.45-52
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• 2001

This paper presents two different models of electrorheological(ER) valves which can be applicable to an automatic cargo handling system at the seaport. Four different ER fluids, which are commercially available, are adopted and their Bingham characteristics are experimentally evaluated with respect to the intensity of electric field. The field-dependent Bingham models are used in the design of two types of ER valves; single-type and divided-type. The governing equations of motion of the ER valves are derived and the principal design parameters are determined based on 200ton platform to be vertically controlled by the ER valves. Both pressure drops due to the applied field and current density required to operate the ER valves are analyzed. In addition, the pressure drops of the cylinder system are evaluated for both ER valves.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.381-382
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• 2007

• IE interfaces
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• v.10 no.2
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• pp.69-77
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• 1997

Material handling equipment such as container cranes and transtainer cranes have made larger and faster to improve the efficiency of container handling. As conditions of use in container terminal have become severe, and also the automation level required has become higher. For the high level automation for transtainer crane, the following characteristics have to be developed 1) Container Terminal Operation & Planning System with high efficiency. 2)Autosteering System of transtainer crane with precise position sensing system using image processing and feedback control system. 3)Automatic Position Identification System with transponder. We have developed an AGSS(Automatic Gantry Steering System) of transtainer crane with image processing technology preferentially. In this paper, the system will be introduced.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.12
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• pp.1302-1312
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• 2008

Relaxed Static Stability(RSS) has been applied to improve flight performance of modern version supersonic jet fighters. Flight control systems are necessary to stabilize an unstable aircraft and to provide adequate handling qualities. Also, flight control systems of modern aircraft employ many safety measure to cope with emergency situations such as a pilot unknown attitude flight conditions of an aircraft in night flight-testing. This situation is dangerous because the aircraft can lose if the pilot not take recognizance of situation. The system called the "Pilot Activated Recovery System" or PARS, provided a pilot initiated automatic maneuver capable of an aircraft recoveries in situations of unusual attitudes, speed and altitude. This paper addresses the concept of PARS with AARS(Automatic Attitude Recovery System), ATCS(Automatic Thrust Control System) and MARES(Minimum Altitude Recovery Estimation System), and this control law is designed by nonlinear control law design process based on model of supersonic jet trainer. And, this control law is verified by real-time pilot evaluation using an HQS(Handling Quality Simulator). The result of evaluation reveals that the these systems support recovery of an aircraft unusual attitude and speed, and improve a safety of an aircraft.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.139-155
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• 1995

This study is concerned with the economic analysis of implementing a material handling system using automated guided vehicle(AGV)s in order to improve the productivity of the production process of chinawares. Analytic hierarchy process(AHP) method for selecting the facilities of material handling systems is presented. Subsequently, as an example, a chinaware production line is analyzed for the economic analysis. The result shows that seven manpowers can be reduced. However the introduction of the new material handling system is turn out to be undesirable due to high initial cost of AGV system, Nevertheless, in the long term, automatic material handling system such as AGV system are expected to play major roles in the modern manufacturing area.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.2
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• pp.243-253
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• 2022

Spent filters with a high radiation dose rate of 2 mSv·hr^-1 or more are not easily managed. So far, the Korean policy for spent filter disposal is to store them temporarily at nuclear power plants until the waste filters can be easily managed. Nuclear power plant decommissioning in Korea is starting with Kori unit 1. Volume reduction of waste generated during decommissioning can reduce the cost and optimize the space usage at disposal site. Therefore, efficient volume reduction is a very important factor during the decommissioning process. A conceptual method, based on the experiences of developing 200 and 800 ton compactors at Orion EnC, has been developed considering worker exposure with the followings a crusher (upgrade of compaction efficiency), an automatic dose measuring system with a NaI(Tl) detector, a shield box, an inner drum to prepare for easy handling of drums and packaging, a 30 ton compactor, and an automatic robot system. This system achieves a volume reduction ratio of up to 85.7%; hence, the system can reduce the disposal cost and waste volume. It can be applied to other types of wastes that are not easily managed due to high dose rates and remote control operation necessity.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.231-233
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• 2007

In this paper we present a new visual approach for the robust bin-picking in a two-step concept for a vision driven automatic handling robot. The technology described here is based on two types of sensors: 3D laser scanner and CCD video camera. The geometry and pose(position and orientation) information of bin contents was reconstructed from the camera and laser sensor. these information can be employed to guide the robotic arm. A new thinning algorithm and constrained hough transform method is also explained in this paper. Consequently, the developed bin-picking demonstrate the successful operation with 3D hole object.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.4
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• pp.410-418
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• 1999

This paper describes the use of residual and parameter identification methods for fault detection in an air handling unit. Faults can be detected by comparing expected condition with the measured faulty data using residuals. Faults can also be detected by examining unmeasurable parameter changes in a model of a controlled system using a system identification technique. In this study, AutoRegressive Moving Average with seXtrnal input(ARMAX) and AutoRegressive with eXternal input(ARX) models with both single-input/single-input and multi-input/single-input structures are examined. Model parameters are determined using the Kalman filter recursive identification method. Regression equations are calculated from normal experimental data and are used to compute expected operating variables. These approaches are tested using experimental data from a laboratory's variable-air-volume air-handling-unit.