• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.8 s.338
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• pp.27-34
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• 2005

In this paper, FPGA It/w and S/W Embedded system for LDM remote control is implemented. XScale CPU is used on developed system and in communcation ethenet and serial is used. CPU interface with H/W LDM rotation and to drive LDM FPGA logic is implemented, to transmit LDM data from long distance command packet is composed, for S/W Embedded linux is used to design linux device driver and linux application program. This S/W is run by module so by loading this module to linu)( file system it can do any movement. Also by compiling Embedded linux to the system it can lower the price of the system. By using this H/W and S/W theory it can be used on any other embedded system.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.2
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• pp.56-62
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• 1999

This paper is concerned with the design and the construction of a moving magnet type linear DC motor(MM type LDM) for instrumentation. A mathematical model for the design of a LDM is developed and a permeance method is used to calculate the effective flux density in the air gap. The flux distribution in the air gap is analyzed and the width of iron core should be determined in order not to saturate the iron core by caluclating maxmum flux density. The design data culculated by a permeance method are compared with the analyzed results using FEM(MAXWELL 2D). The errors between two results are corrected. The tested LDM is constructed using the corrected design data. The results of experiment for thrust characteristics are compared with simulation.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.132-134
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• 2001

In this paper, by designning the width of the stator coil, double sided excitation LDM with multi-separated winding which is possible to obtain the constant thrust force is proposed. Using Maxwell 2D, Empulse, we were proved the characteristic analysis of LDM accoding to ratio magnet width venus coil width of LDM. Though designning for double sided excitation LDM with multi-separated winding, we could be achieved the constant thrust and rapidly time responses within the operating region.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.6
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• pp.411-420
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• 1986

Quantization noise of nonadaptive Linear Delta Modulation(LDM) and adaptive Constant Factor Delta Modulation(CFDM) systems is studied. The formulas for quantization noise of CFDM system are derived on the basis of the rusults of LDM. And the output signal-to-quantization noise ratios(SNR) in LDM and CFDM systems are calculated in the range of bit rates from 16[Kb/s] to 96[Kb/s]. By comparing LDM and CFDM, it is known that the adaptive DM is superior to non-adaptive DM by 8[dB] when bit rate is 20[Kb/s] and SNR advantage increases to 14[dB] when bit rate is 56[Kb/s]. All the theoretical results agree well with the experimental results.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.196-199
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• 1998

LDM(Linear DC Motor) are used in high speed, high-precision position control system. Because of these advatages, LDM has already used in the motor of pen-recorder, magnetic-disk devices. Under the limited dimension, we propose the design method of LDM by magnetic circuit. In this paper, a relation between the thrust constant and size of a LDM that is moving coil type with unipolar is described, which is defined as a simple relational equation. To maximize the rate of thrust to the volume of LDM, the magnetic flux density in the yoke is adjusted to the value of magnetic equation. By the magnetic field analysis(FEM), the validity of the equation is confirmed.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2505-2508
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• 2003

In this paper, we propose the method to control the position of LDM(Linear DC Motor) using vision system. The proposed method is composed of a vision system for position detecting, and main computer calculates PID control output which is deliver to 80il actuator circuit in serial communication. To confirm the usefulness of the proposed method, we experimented about position control of a small size LDM using CCD camera which has a performance 30frames/sec as vision system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.447-449
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• 2015

Advanced television systems commitee (ATSC) 3.0 은 효율적 주파수 사용을 위하여 여러 개의 방송 스트림을 계층 분할하여 전송하는 layered division multiplexing (LDM) 기술과 연집오류에 의한 성능저하를 방지하기 위하여 시간 인터리버 (time interleaver) 기술을 채택하였다. 본 논문에서는 LDM 기반 시간 인터리버 기술의 각 계층별 성능을 모의실험을 통하여 다양한 채널 환경에서 평가하고 효과를 분석하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.208-218
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• 2017

This study aims to develop the Vehicle Local Dynamic Map (V-LDM) and demonstrate its performance for providing dynamic map data efficiently to the vehicle control module. Firstly, the concept of the in-vehicle LDM has been established and then the system has been carefully designed according to the international standards. The high-precision digital map embedded in LDM has been designed to incorporate the lane-level information of road network, and the Dynamic Map protocol (DM protocol) which is a message protocol including the road data with dynamic traffic event data has been defined. The performance test of the proposed system has been conducted in the uninterrupted road section of Kyungbu expressway, showing that both of the data size and the elapsed time to finish the process are almost linearly proportional to the length of target road. Finally, it is recommended that the length of target road for DM protocol be less than 250m.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.589-591
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• 2004

In this paper, we developed a laser distance measurement(LDM) system based on DSP. We applied PPD(Pulsed Phase Detection) algorithm to the LDM system. The PPD algorithm calculate the distance from the LDM system to the object by using phase detection. Reference waveform at a fixed frequency is sampled by both the inner-loop and outer-loop pulse signal. The LDM system detects the difference of phase between the sampled signals. We obtained an accuracy of ${\sigma}=25.5mm$ from the LDM system.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.160-163
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• 1999

The thrust force of moving magnet-type linear direct current motors(MM-LDM) is analyzed in this study. A moving magnet-type LDM consists of a stator and a carriage. The stator is composed of two stick shaped electro magnetics and the carriage consists of a movable permanent magnet that is located between the two electromagnets. The method for calculating the thrust force of an MM-LDM is to analyze the energy gradient which is determined by the distribution of magnetic flux. And this paper describes the development of the generalized machine theory for d.c. linear motors and its application to determine the motor parameters.