Pin Distribute Method of Twist Cable at Military Unmanned Vehicle Wiring Unit Connector
은희현 Hee-hyun Eun , 노동규 Dong-gyu Roh , 곽규민 Gyu-min Kwak , 김재승 Jae-seung Kim , 이철 Chul Lee
24(4) 245-250, 2020
은희현 Hee-hyun Eun , 노동규 Dong-gyu Roh , 곽규민 Gyu-min Kwak , 김재승 Jae-seung Kim , 이철 Chul Lee
DOI: JANT Vol.24(No.4) 245-250, 2020
Currently, unmanned military vehicles under development in Korea have more devices to carry out various missions, and interface cables between them are also increasing. In addition, due to a small space problem inside the unmanned vehicle, devices are required to be miniaturized and integrated. For two reasons, connectors also need to be selected, which makes them vulnerable to noise due to the closer distance between the pins. In this paper, we analyzed how much the magnetic field produced by noise at the connector pin where cable twist is released affects the surrounding pin and presented the guide for optimal pin placement. First, the effect of magnetic field is greater than the crosstalk between pin and pin. Second, the magnetic field on both sides between + and - is strong when approaching one step with noise source. Third, the magnetic field strength is improved when setting the ground pin as the ground pin between the noise and the original signal when approaching the A noise source and the two steps. Fourth, in the case of a differential mode communication, the optimal placement area of the sensitive signal was presented according to positions Tx± and Rx±.
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Design and Implementation of Air Vehicle Test Equipment for Unmanned Aerial Vehicle
권상은 Sang-eun Kwon
24(4) 251-260, 2020
권상은 Sang-eun Kwon
DOI: JANT Vol.24(No.4) 251-260, 2020
Unlike manned aerial vehicles, because an unmanned aerial vehicle (UAV) has a limitation which allows only remote test during flights, it is very important to maintain the high reliability of the vehicle through pre- and post-flight tests. To this end, this paper designed an air vehicle test equipment (AVTE) for UAV which meets the derived hardware and software requirements. Based on this design, the AVTE was implemented in accordance with the actual test scenario. The implemented AVTE has the advantage of reducing the time and cost required for the test of UAV by allowing the operator to perform automatic or manual tests for necessary parts in various situations such as before and after starting engine and pre- and post-flight tests. Furthermore, this study is expected to help with the design and implementation of AVTE for other UAVs.
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Heat Dissipation Design for KW Class Power Control Unit Mounted on Aircraft Store
최석민 Seok-min Choi , 김형재 Hyung-jae Kim , 정재원 Jae-won Jung , 이철 Chul Lee
24(4) 261-266, 2020
최석민 Seok-min Choi , 김형재 Hyung-jae Kim , 정재원 Jae-won Jung , 이철 Chul Lee
DOI: JANT Vol.24(No.4) 261-266, 2020
When a KW-class power control unit is installed in an aircraft installation, a heat dissipation design for a large amount of heat generated during power conversion should be considered. Failure to provide adequate heat dissipation can lead to equipment malfunction and fire, which can be a fatal factor in aviation operations. This paper describes the heat dissipation design of a KW-class power control unit installed in aircraft installation. The design and manufacturing test were conducted through computerized analysis, and the analysis model was corrected by confirming the rapid heat generation phenomenon of the heating element due to high power control. After the model revision, the design was improved, and the high-temperature operation test of the US military standard MIL-STD-810G was performed to confirm the feasibility of the improved design.
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A Proposal of Time Synchronization amongst Wireless Sensors for Ship Diagnosis and Maintenance Supporting
김병국 Byoung-kug Kim
24(4) 267-272, 2020
김병국 Byoung-kug Kim
DOI: JANT Vol.24(No.4) 267-272, 2020
In order to monitor in large area of a ship without any concerns of spacial environments, there can be the use of many sensors that support wireless network technologies. Through the deployment of the wireless sensors and their autonomous network formations, the status of a ship can be easily monitored in real time. Moreover, if all the sensors are timely synchronized with each other, the locations and the moving directions of certain events can be estimated. Thus, the time synchronization amongst wireless sensors are crucial. In this paper, we propose an algorithm which supports reduced message transmissions between the sensors for synchronization.
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The Development for KASS Reference Station Site
조성룡 Sunglyong Cho , 장현진 Hyunjin Jang , 정환호 Hwanho Jeong , 이병석 Byungseok Lee , 남기욱 Giwook Nam
24(4) 273-279, 2020
조성룡 Sunglyong Cho , 장현진 Hyunjin Jang , 정환호 Hwanho Jeong , 이병석 Byungseok Lee , 남기욱 Giwook Nam
DOI: JANT Vol.24(No.4) 273-279, 2020
In the Korea’s SBAS(KASS), reference site is an important infrastructure facility for the collecting and monitoring GPS/GEO signals. The SBAS reference station has an clear requirements than other regular monitoring stations. It requires constant maintenance during the system operation. The development for KRS site should be prepared for site survey, site construction, antenna geodetic survey, equipment installation and operation. Site survey is initially performed as an important step to predict site availability and system performance. The operation center must provide the reference site, equipment room, and appurtenant to satisfy the site requirements. The position of antennas is very important information, and accuracy must be secured through the geodetic survey. Measurement collected at the from precise antenna are provided to the KASS processing station. The position of antenna should be maintained through continuous position checks and updates during the operation. When the development of the KRS site is completed, it performs tasks for installing and operating the KRS equipment. In this paper, we presented the procedures and some results for the development of the 7 KRS sites.
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A Method of Controlling the Driving and Electric Braking Force of the Electric Motor
곽연근 Yeon-geun Kwag
24(4) 280-284, 2020
곽연근 Yeon-geun Kwag
DOI: JANT Vol.24(No.4) 280-284, 2020
To improve maintenance, environmental issues, efficiency, and economics to supplement the current air braking problems, braking power related to the entire driving range of electric brakes was presented in all areas from stop to high speed. As a result, the efficiency of braking power and cutting-edge technology have expanded energy use, and through this paper, noise in all driving ranges can be reduced, and maintenance costs can be reduced. The traction motor must bring the variable speed of the traction motor and the terminal voltage of the traction motor to drive high-speed driving characteristics that control the maximum voltage of the inverter. Therefore, we studied driving and brake changes through simulation.
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Phase Locked Loop based Time Synchronization Algorithm for Telemetry System
김건희 Geon-hee Kim , 진미현 Mi-hyun Jin , 김복기 Bok-ki Kim
24(4) 285-290, 2020
김건희 Geon-hee Kim , 진미현 Mi-hyun Jin , 김복기 Bok-ki Kim
DOI: JANT Vol.24(No.4) 285-290, 2020
This paper presents a time synchronization algorithm based on PLL for application to telemetry systems and implement FPGA logic. The large aircraft of the telemetry system acquires status information through each distributed acquisition devices and analyzes the flight status in real time. For this reason, time synchronization between systems is important to improve precision. This paper presents a PLL based time synchronization algorithm that is less complex than other time synchronization methods and takes less time to process data because there is minimized message transmission for synchronization. The validity of proposed algorithm is proved by simulation of Python. And the VHDL logic was implemented in FPGA to check the time synchronization performance.
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Maximum Power Point Tracking of Photovoltaic using Improved Particle Swarm Optimization Algorithm
김재정 Jae-jung Kim , 김창복 Chang-bok Kim
24(4) 291-298, 2020
김재정 Jae-jung Kim , 김창복 Chang-bok Kim
DOI: JANT Vol.24(No.4) 291-298, 2020
This study proposed a model that can track MPP faster than the existing MPPT algorithm using the particle swarm optimization algorithm (PSO). The proposed model highly sets the acceleration constants of gbest and pbest in the PSO algorithm to quickly track the MPP point and eliminates the power instability problem. In addition, this algorithm was re-executed by detecting the change in power of the solar panel according to the rapid change in solar radiation. As a result of the experiment, MPP time was 0.03 seconds and power was 131.65 for 691.5 W/m2, and MPP was tracked at higher power and speed than the existing P&O and INC algorithms. The proposed model can be applied when a change in the amount of power is detected by partial shading in a Photovoltaic power plant with Photovoltaic connected in parallel. In order to improve the MPPT algorithm, this study needs a comparative study on optimization algorithms such as moth flame optimization (MFO) and whale optimization algorithm (WOA).
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Circular Sector-Shaped 2 GHz Band Power Divider-Combiner
김영 Young Kim
24(4) 299-304, 2020
김영 Young Kim
DOI: JANT Vol.24(No.4) 299-304, 2020
This paper proposes the design of circular sector shaped power divider-combiner with a planar structure. This structure can be constructed in series, and due to the circular sector shape, it is possible to simplify circuit configuration and improve the amplitude and phase balanced characteristics of the output. It has a simple input matching circuit and an RC parallel circuit was inserted between the output ports to improve the reflection coefficient and isolation of the output. Since the designed divider-combiner are structurally designed in a symmetrical shape of a sector, even if the output ports are composed of two or four output ports, they have excellent characteristics with an amplitude balance of ± 0.1 dB and a phase balance of ± 1o between outputs. To prove these characteristics, it was confirmed that the characteristics of the planar power divider-combiner fabricated at an operating frequency of 2 GHz are in good agreement with the simulation.
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Design of Advanced PCM Encoder Architecture for Efficient Channel Information Memory Management
노윤희 Yun-hee Ro , 김건희 Geon-hee Kim , 김동영 Dong-young Kim , 김복기 Bok-ki Kim , 이남식 Nam-sik Lee
24(4) 305-313, 2020
노윤희 Yun-hee Ro , 김건희 Geon-hee Kim , 김동영 Dong-young Kim , 김복기 Bok-ki Kim , 이남식 Nam-sik Lee
DOI: JANT Vol.24(No.4) 305-313, 2020
Telemetry system is a system that transmits status information data acquired from the aircraft to the ground station. PCM encoder needs memory to store channel information in order to generate a frame format using the acquired data. Generally, telemetry systems in large aircraft require much larger memory for the increased acquisition channel information due to the increased sensors and subsystems. However, they have difficulty to store all channel information in limited memory. In this paper, we suggests and implements an advanced PCM encoder that can efficiently manage memory by minimizing duplicated channel information. This novel PCM encoder allocates duplicated channel information to memory only once. And, sub commutation channels having different information for each minor frame are allocated to the memory by multiples of sub commutation channels. Finally, the suggested PCM encoder was proved by simulation that composed channels of various measurement cycles.
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Fault Detection through the LASAR Component modeling of PLD Devices
표대인 Dae-in Pyo , 홍승범 Seung-beom Hong
24(4) 314-321, 2020
표대인 Dae-in Pyo , 홍승범 Seung-beom Hong
DOI: JANT Vol.24(No.4) 314-321, 2020
Logic automated stimulus and response (LASAR) software is an automatic test program development tool for logic function test and fault detection of avionics components digital circuit cards. LASAR software needs to the information for the logic circuit function and input and output of the device. If there is no component information, normal component modeling is impossible. In this paper, component modeling is carried out through reverse design of programmable logic device (PLD) device without element information. The developed LASAR program identified failure detection rates through fault simulation results and single-seated fault insertion methods. Fault detection rates have risen by 3% to 91% for existing limited modeling and 94% for modeling through the reverse design. Also, the 22 case of stuck fault with the I/O pin of EP310 PLD were detected 100% to confirm the good performance.
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Algorithm Development of Human Body Bio-Signal Measurement based on Sampling Time using Doppler Radar Information
유재춘 Jae-chun Ryu , 이명의 Myung-eui Lee
24(4) 322-327, 2020
유재춘 Jae-chun Ryu , 이명의 Myung-eui Lee
DOI: JANT Vol.24(No.4) 322-327, 2020
Recently, a research on obtaining a vital signal using a Doppler radar has been developed and is used as a technology applied to patients in bed. However, in the case of the measured pulse, the respiration signal is generated as noise, resulting in a problem of lowering accuracy. In this paper, we propose a bio-signal measurement algorithm based on the sampling point to improve the accuracy of the signal for measuring the pulse rate when measuring bio-signals using a Doppler radar. The proposed algorithm improves the accuracy of the measured bio-signal by removing noise generated when measuring biosignals based on two sampling points. Compared with actual medical equipment and existing bio-signal algorithms, it is more than 90% similar to medical equipment. In addition, it was confirmed that severe amplitude change was minimized compared to the existing algorithm.
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