• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.1-11
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• 2009

This paper illustrates a case study of PLC logic simulation in a car manufacturing system. It was developed to simulate and verify PLC control program for automobile panel AS/RS. Because car models become varied, the complexity of supply problem is increasing in the car manufacturing system. To cope with this problem, companies use the AS (automated storage) and RS (retrieval system) but it has logical complexity. Industrial automated process uses PLC code to control the AS/RS, however control information and control codes (PLC code) are difficult to understand. This paper suggests a PLC simulation environment, using 3D models and PLC code with realistic data. Data used in this simulation is based on realistic 3D model and I/O model, using actual size and PLC signals, respectively. The environment is similar to a real factory; users can verify and test the PLC code using this simulation before the implementation of AS/RS. Proposed simulation environment can be used for test run of AS/RS to reduce implementation time and cost.

• Journal of the Korea Society of Computer and Information
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• v.14 no.3
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• pp.13-26
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• 2009

In this raper, We propose the alternative solution, RTOS-based system to replace the PLC 4hat has used the automation system for industrial processes. RTOS-based system is constructed the PC and RTOS as hardware and software. It overcomes the limit of PLC and guarantees the stability and reliability. Also, PC has better performance and cheaper than PLC when operating and constructing the system. For many manufactures, these benefits alone are all the reason they need to switch from PLC-based system to RTOS-based system. To use the RTOS-based System, the PLC program needs the conversion to the RTOS task. And how to transform is the most important issue. So, we propose conversion method through the system model. The system model defines the operation of each module as the task after the system divided into module. Because the system divided into modules can control, the performance and the functionality of system improve, and the system can deal with a problem easily when repairing and changing.

• Convergence Security Journal
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• v.22 no.4
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• pp.75-84
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• 2022

In the 4th industry, drones are being used while having a close relationship with our lives. The development and use of various drones suggests a new paradigm for the domestic industry in the future, and is expected to become more advanced and scientific. Meanwhile, in the field of defense, efforts are being made in various ways to overcome the social phenomenon of reduced service resources. It is concentrating its efforts on strengthening the national defense power by preparing an exit strategy to supplement the shortage of service resources and to maintain and improve combat power, and by combining various science and technology related to the 4th industry. The military is planning to reinforce its combat power in connection with future industries to effectively respond and perform missions in preparation for the future combat aspects that have been researched and planned, and is planning an unmanned combat system for the science and technology army by investing a separate budget. Therefore, we systematically introduce and utilize drones, which are the core of the unmanned combat system, to create more active combat power and seek countermeasures for the battle vacuum, It is expected to provide a new paradigm for the battlefield when using advanced technology developed in the private sector and grafting it to the military sector.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.170-177
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• 2020

This study examined the clamping force control method and the braking performance test results of an electromechanical brake (EMB) using braking test equipment. Most of the studies related to EMBs have been carried out in the automotive field, dealing mainly with the static test results for various control methods. On the other hand, this study performed a dynamic performance evaluation. The three-phase interior permanent magnet synchronous motor (IPMSM) was applied to drive the actuator of the EMB, and the analysis was verified by JMAG(Ver. 18.0), which is finite element method (FEM) software. The current control, speed control, and position control were used for clamping force control of the EMB, and the maximum torque per ampere (MTPA) control was applied to the current controller for efficient control. The EMB's emergency braking deceleration performance was tested in the same way as conventional pneumatic brake systems when the wheel of a train rotates at 110 km/h, 230 km/h, and 300 km/h. The emergency braking time, with the wheel stopped completely at the maximum rotational speed, was approximately 73 seconds. The similarity of the braking time and deceleration pattern was verified through a comparison with the performance test results of the pneumatic brake system applied to the next generation high-speed railway vehicle (HEMU-430X).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.634-639
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• 2020

In general, the stability and response characteristics of the system can be improved by changing the pole position because a nonlinear system can be linearized by the product of a 1st and 2nd order system. Therefore, a controller that moves the pole can be designed in various ways. Among the other methods, LQ control ensures the stability of the system. On the other hand, it is difficult to specify the location of the pole arbitrarily because the desired response characteristic is obtained by selecting the weighting matrix by trial and error. This paper evaluated a method of selecting a weighting matrix of LQ control that moves multiple double poles with Jordan blocks to real poles. The relational equation between the double poles and weighting matrices were derived from the characteristic equation of the Hamiltonian system with a diagonal control weighting matrix and a state weighting matrix represented by two variables (ρ_d, ϕ_d). The Moving-Range was obtained under the condition that the state-weighting matrix becomes a positive semi-definite matrix. This paper proposes a method of selecting poles in this range and calculating the weighting matrices by the relational equation. Numerical examples are presented to show the usefulness of the proposed method.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.451-457
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• 2020

In this study, the degree of motion sickness displayed according to actions in virtual reality is measured based on the SSQ tool, a measuring tool, and factors and symptoms affecting cyber motion sickness are investigated through comparative analysis. In the first experiment, the operation method experiment, the simple operation method is measured to be highly affected by the Nausea factor. As symptoms of this, nausea, burp and headache symptoms were developed. In the second experiment, the larger the body rotation radius, the higher the motion sickness was measured, and the greater the influence of Nausea factors. Symptoms of this were the symptoms of burping, headaches, and a full head. In the third experiment, the physical mobility experiment, motion sickness was measured highly in the non-action controller. It was measured to be greatly affected by the Nausea factor. Symptoms of this include fever, headache, and a full head. Through this study, we found that the more fixed and simple the body is operated in virtual reality, the more sensitive the user is to motion sickness, and the larger the radius of rotation, the more sensitive it is to motion sickness. This study is meaningful in identifying factors and symptoms that affect motion sickness and VR manipulation, and is expected to be used by developers in the future to recognize the degree and symptoms of motion sickness of users and to develop content.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3626-3632
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• 2010

Some design changes were made to enhance the uniformity of temperature distribution inside the chamber of semiconductor test equipment. The design changes include the installation of adjustable airflow controller inside the chamber, the alignment of the centers of heater and match plate, the change in the size and the shape of holes in match plate base, and the addition of new holes of 2 mm diameter in order to allow airflow directly to the temperature sensors. In order to verify their effects, the temperature distributions inside the chambers were measured using 32 RTD sensors before and after the design changes. The temperature distributions were in the ranges of 87.1 to $91.5^{\circ}C$ ($90{\pm}2.9^{\circ}C$) and 89.5 to $90.8^{\circ}C$ ($90{\pm}0.8^{\circ}C$) before and after the design changes, respectively. The above temperature distribution after design changes was maintained for longer than 15 minutes, which satisfied the target temperature range of $90{\pm}1^{\circ}C$ for longer than 10 minutes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.494-500
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• 2019

The purpose of this study was to determine a method to prevent damage during the transfer of loading through optimal design of loading transfer software for an ammunition-carrying armored vehicle. Typically, an ammunition carrier armored car is equipped with an automated charge transfer system. The load is intermittently damaged during the loading of the cargo, and this needs to be improved. The following improvements and verification tests were carried out. As impact speed increased, the loading speed was reduced 60%, and a special fixture utilizing a force gauge was developed and tested. If the maximum current of 11A for the servo controller is output when the load of the conveyor is generated by interference inside the loading tube, there is a possibility of charge breakage. If the maximum current is low, the load cannot be loaded. In the loading test for the ammunition carrier armored car with the actual charge, the improved design was found to be valid, as the load was not damaged and occurred nominally.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.660-665
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• 2018

Research into underwater wireless networks that enable the monitoring and controlling of the ocean environments has been continuing for disaster prevention and military proposes, as well as for the exploitation of ocean resources throughout the world. A research group led by Hoseo university has been studying a distributed underwater monitoring and controlling network. In this study, we developed an interpolator for acoustic communication between an underwater base station controller and underwater base station, which is included in this network. The underwater acoustic communication provided by this network defines four links whose sampling rates are different. Low power consumption is one of the most important requirements. Therefore, we adopted CIC interpolators, which are known to act as filters with a low power consumption, and some CIC interpolators with an appropriate changing rate were selected depending on the link. However, these interpolators have a large passband drop and wide transition region. To solve these problems, we added a compensator and half-band filter. After verifying the algorithm by using Matlab, we designed and verified it with Verilog-HDL in a ModelSim environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.817-825
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• 2017

The AC-common bus microgrid system can overcome several weaknesses of the DC microgrid system by interconnecting the DC/AC inverters used for renewable energy with an AC network. Nevertheless, the unbalanced loads inherent in the electric power systems of island and small communities can deteriorate the performance of the AC microgrid system. This is because of the limited voltage regulation capability and mixed power flow in the voltage source inverter. In order to overcome the unbalanced load condition, this paper proposes a voltage and current control algorithm for the 4-leg inverter based on the single phase d-q control method, as well as the modeling of the voltage controller using Matlab/Simulink S/W. From the S/W simulation and experiment of the 250KW proto-type inverter, it is confirmed that the proposed algorithm is a useful tool for the design and operation of the AC microgrid system.