• Journal of Drive and Control
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• v.19 no.3
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• pp.9-15
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• 2022

This paper proposes a method for constructing and verifying datasets used in deep learning technology, to prevent safety accidents in automated construction machinery or autonomous vehicles. Although open datasets for developing image recognition technologies are challenging to meet requirements desired by users, this study proposes the interface of virtual simulators to facilitate the creation of training datasets desired by users. The pixel-level training image dataset was verified by creating scenarios, including various road types and objects in a virtual environment. Detecting an object from an image may interfere with the accurate path determination due to occlusion areas covered by another object. Thus, we construct a database, for developing an occlusion area detection algorithm in a virtual environment. Additionally, we present the possibility of its use as a deep learning dataset to calculate a grid map, that enables path search considering occlusion areas. Custom datasets are built using the RDBMS system.

• Journal of Drive and Control
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• v.19 no.1
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• pp.26-33
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• 2022

This study dealt with a self-propelled spinach harvester, which is capable of carrying out sequential harvesting work. This study aimed to find the cause of the harvester's occasional performance deterioration, which occurs in the process of simplifying the hydraulic circuit, using a multi-domain analysis model. The study was carried out in the following manner. First, a hydraulic system analysis model, which combines linear motion, rotary motion, hydrodynamic behavior, and an electrical signal, was developed through SimulationX software, specialized in multi-domain analysis. Second, a scenario for single behavior and coupled behavior was set out on an actuator basis. Third, the flow rate of the hydraulic system, which is not required for the movement of the actuator, was quantitatively analyzed. The results showed that a change in oil temperature was the cause of the harvester's occasional performance deterioration. And the higher the oil temperature, the more serious the performance deterioration, especially as the number of actuators operated simultaneously was small.

• Journal of Drive and Control
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• v.19 no.1
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• pp.69-75
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• 2022

This study aimed to develop solutions for the intermittent performance deterioration of self-propelled spinach harvesters through analysis model. The study was conducted in the following manner. First, changes in performance deterioration and surplus flow, which result from oil temperature changes, were analyzed by simulating actual sequential harvesting movements, which involve driving with actuators operated simultaneously, by analysis model developed in a previous study. Second, fundamental solutions for surplus flow problems were presented. Third, the solutions were applied to a virtual environment to present their practicality and quantitative effects. The two solutions based on the study results were as follows. First, a closed center-type directional control valve was applied to the hydraulic circuit. Second, an unloading system was set up through an on-off solenoid valve.

• Journal of Drive and Control
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• v.19 no.2
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• pp.36-44
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• 2022

Hydrogen energy as an alternative source of energy has been receiving tremendous support around the world, and research is being actively conducted accordingly. However, most of the studies focus on hydrogen storage tanks and only are few studies on interpreting the hydrogen filling system itself. In this study, with reference to SAE J2601, a hydrogen fueling protocol, a simulation model was developed that can confirm the behavior of the vehicle's internal tank during hydrogen fueling. With respect to factors such as fuel supply temperature, ambient temperature, and pressure increase rate, the developed model can check the change of temperature and pressure in the tank and the state of hydrogen charging during hydrogen fueling. The validity of the developed simulation model was confirmed by comparing the simulation results with the experimental results presented in SAE J2601.

• Journal of Drive and Control
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• v.19 no.2
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• pp.11-16
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• 2022

It is important to measure the excavator's work productivity that estimates the bucket's payloads on a process. If the bucket isn't filled at every working cycle, the excavator's operator has to drive the machine more to achieve his work quota. If bucket is filled over with the load, the other way around, the transferred object has to spread out on the workplace. That causes additional work to clean the site. This paper proposes a method that can estimate the bucket's payload to improve the excavator's work productivity. This method assumes that the excavator is a lumped mass system. And it uses a 3 points angle (boom link, arm link, swing) and 2 points pressure (boom cylinder's input port and output port) of measurable data. Depending on assumptions, the bucket's payload can be calculated by the payload's motion equation. And this suggested method can be verified by simple experiments.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.327-330
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• 2022

이 연구는 자치경찰제도 도입에 따른 재난대응 실태를 살펴보고 개선방안을 제시하기 위한 목적의 연구로서 연구의 완성을 위하여 경찰의 재난대응 매뉴얼과 관련 통계자료, 법령 등을 종합적으로 검토하여 개선하는 방안을 제시하고자 한다. 자치경찰제도가 도입됨에 따라 기존의 범죄예방 및 기타 치안서비스 제공 시스템에 많은 변화가 발생하였다. 자치경찰제도는 기존의 중앙통제식 경찰제도에서 벗어나 각 지역의 실정에 맞도록 경찰을 운용하는 방식이다. 이러한 자치경찰제도 도입에 따라 많은 기대와 우려가 공존하고 있는 상황에서 자치경찰제도의 취약점이라고 볼 수 있는 대규모 인력이 동원 상황 발생 시 대응에 대하여 여전히 의문을 가지고 있다. 그 중 대형 대난 발생 시 자치경찰의 역할이 대하여 살펴본 결과, 현재 경찰이 대형재난 발생 시 대형재난 현장에서 2차 피해 예방을 위한 현장 통제 및 추가적인 재난 피해 예방, 요구호자 구조 등의 업무를 수행한다. 그러나, 자치경찰의 경우 대규모 재난에 대응하기가 쉽지 않은 탓에 대형재난에 취약할 수 밖에 없기 때문에 이 연구에서는 대형 재난 발생 시 기본적인 경찰의 재난 현장 통제 및 2차 피해 예방활동과 함께 인근 지역 자치경찰과 협동 재난 대응 활동 및 컨트롤 타워 등 제안과 같은 방안을 제안하였다.

• Journal of Drive and Control
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• v.20 no.4
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• pp.35-44
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• 2023

This study aimed to analyze the performance of hydraulic systems for dental chair when long working hours makes the temperature of hydraulic fluid rise. The study was carried out in the following manner. First, 'cylinder's clearance' was reflected in the three kinds of hydraulic circuits, which were developed through the preceding study, in order to analyze oil leak. Second, 12 cases of simulations comprised of the up and down of cylinders were carried out. Third, it was determined whether the cylinder velocity of dental chair surpasses 1cm/s required in the development even in the hydraulic fluid temperature of 60℃. In conclusion, this study used SimulationX to verify the performance stability at high temperatures using three types of hydraulic circuits designed to develop a Korean unit chair.

• Journal of Drive and Control
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• v.20 no.4
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• pp.140-149
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• 2023

Wire harness is a component for efficient control when electronic parts are required such as construction machinery and electric vehicles. With emerging issues such as autonomous driving and automation in construction, a wire harness composed of multiple cables has become an essential part because more electronic parts are required. However, when a wire harness failure occurs, systems can be stopped, accidents can occur, and economic damage can be significant. Therefore, in this paper, we developed a digital fault screening system that could easily and quickly diagnose faults in the wire harness. The principle of the developed system was to sequentially send pulse signals to the wire harness and use returned signals to perform fault detection. As a result of diagnosing faults using the developed failure detection system, a detection accuracy of 99.9 % was confirmed through the experiments.

• Journal of Korea Port Economic Association
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• v.27 no.1
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• pp.75-94
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• 2011

This paper is concerned about applying the AHP(Analytic Hierarchy Process) for a priority analysis of equipment operation plan to improve productivity of the container terminal in Gwangyang port. In this study, main elements of container terminal are assumed as into yard equipment area, transport equipment area, berth equipment area and C/Center area. A questionnaire is used to collect the opinions of equipment operating department and operational planning department. On the whole, the result of the analyses reveals that the most important area is yard equipment area. Examining each department is responses, equipment operating department preferred the C/Center area to other areas, on the other hand, operational planning department preferred yard equipment area. The result of this study suggests some guidelines for deciding priority of operation plan in the container terminal.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.893-905
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• 2011

CUPPS is the latest international standard passenger processing system which is operated with airlines' check-in system, DCS (Departure Control System) in order to provide check-in and boarding services to passengers. The CUPPS standard has been revised in August 2009 leading by IATA (International Air Transport Association) who recommends replacing old legacy common use system with CUPPS to airports and airlines around the world. IATA is expecting to reduce the installation and maintenance cost of CUPPS by standardizing various legacy common use systems and device controls. Airlines are also expecting to take advantage of the system to reduce the application development cost as developing only one standard CUPPS application instead of developing multiple applications for nonstandard legacy systems. This research which focuses on development completed AIRCUS, R&D project of ministry of land, transport and maritime affairs accomplished by IIA, will present the result of pilot trial and the effective approach methods to increase the possibility of expanding overseas business by comparing old legacy system with CUPPS to prove the dominance of CUPPS over the legacy systems as well as doing foreign case studies.