• Title/Summary/Keyword: digital payload

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Electrical Interfaces Compatibility Analysis for the COMS TWTA (통신해양기상위성 진행파관증폭기 전기접속 적합성 해석)

  • Koo, Ja-Chun;Choi, Jae-Dong
    • Aerospace Engineering and Technology
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    • v.7 no.1
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    • pp.108-114
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    • 2008
  • The aim of this analysis is to verify the electrical compatibility of the interfaces which exist between TWTA(Travelling Wave Tube Amplifier) which is equipment of the Ka-band payload in COMS (Communication, Ocean and Meteorological Satellite) and external equipments. For each interface, this study checked the compatibility between equipments for the power links, commands, digital telemetry, analog telemetry, and failure condition or AIT(Assembly, Integration and Test) errors. In addition with this interface compatibility verification, this study outputs electrical and manufacturing recommendations to be applied at harness level.

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Design of a DSP-Based Adaptive Controller for Real Time Dynamic Control of AM1 Robot

  • S. H. Han;K. S. Yoon;Lee, M. H.;Kim, S. K.
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.100-104
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    • 1998
  • This paper describes the real-time implementation of an adaptive controller fur the robotic manipulator. Digital signal processors(DSPs) are special purpose micro-processors that are particularly powerful for intensive numerical computations involving sums and products of variables. TMS320C50 chips are used in implementing real time adaptive control algorithms to provide an enhanced motion for robotic manipulators. In the proposed scheme, adaptation laws are derived from the improved Lyapunov second stability analysis based on the direct adaptive control theory. The adaptive controller consists of an adaptive feedforward controller and feedback controller. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by simulation and experimental results for a assembling robot.

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Koh Chang Island Eco-Tourism Mapping by Balloon-born Remote Sensing Imagery System

  • Kusanagi, Michiro;Nogami, Jun;Choomnoommanee, Tanapati;Laosuwan, Teerawong;Penaflor, Eileen;Shulian, Niu;Zuyan, Yao
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.894-896
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    • 2003
  • Koh Chang Island is located near the east border of Thailand. The government of Thailand promotes the island as a model of eco-tourism spots. The Island undeveloped until recent years, is expected to change to major tourist attraction. 'Digital Koh Chang project' has thus. The main objective of this project is to monitor the environment and land use status of the island and to support its sound development. In March 2003, a field survey of this project was planned and field data were collected using both airborne and ground platforms and an ocean vessel. These data were combined with satellite data in the laboratory. This presentation is all balloon-born system field operation. A 5-meter length balloon filled with Helium gas was used, whose payload consisted of two RGB standard color digital still cameras, two directional rotating servo motors, a camera mount cradle as well as signal transmitting and receiving components. A series of aerial high-resolution digital images were rather easily obtained using this inexpensive system, making it possible to monitor intended landscape features in a specific field. Design of simple, low-cost and easily transportable flying platforms and local field surveys using them are useful for getting local ground truth data to calibrate satellite or airborne-based RS data. The design analysis to upgrade the system is further investigated.

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Digital Image Watermarking Algorithm using Integer Block Transform (정수 블록 변환을 이용한 디지털 이미지 워터마킹 알고리즘)

  • Oh Kwan-Jung;Ho Yo-Sung
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.5 s.311
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    • pp.57-67
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    • 2006
  • Intellectual property rights are gathering strength theses days. Because digital contents are easily reproduced and distributed by advanced computers and networks. Digital watermarking is one of the best solutions for this problem. Generally, frequency-domain watermarking algorithms are preferred since they are more robust than spatial-domain algorithms. However, coefficients in the frequency domain are floating-point numbers. Thus, it is not easy to manipulate those floating-point coefficients and frequency-domain watermarking algorithms have some limitations in their applications. In order to overcome this difficulty, we employ an integer transform in this paper. In addition, our proposed algerian can extract the watermark from both the spatial and frequency domains. We embed the watermark into a specific bit-plane of mid-frequency coefficients. This is equivalent to the differential energy watermarking (DEW) in the spatial domain. Our simulation results show that the proposed algorithm is imperceptible, good for the watermark payload, and robustness against various attacks. Moreover, it is more efficient than any other algorithm working in only one domain.

Variable Structure Adaptive Control of Assembling Robot (조립용 로봇의 가변구조 적응제어)

  • 한성현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.04a
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    • pp.131-136
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    • 1997
  • This paper represent the variable structure adaptive mode control technique which is new approach to implement the robust control of industrial robot manipulator with external disturbances and parameter uncertainties. Sliding mode control is a well-known technique for robust control of uncertain nonlinear systems. The robustness of sliding model controllers can be shown in contiuous time, but digital implementation may not preserve robustness properties because the sampling process limits the existence of a true sliding mode. the sampling process often forces the trajectory to oscillate in the neighborhood of the sliding surface. Adaptive control technique is particularly well-suited to robot manipulators where dynamic model is highly complex and may contain unknown parameters. Adaptive control algorithm is designed by using the principle of the model reference adaptive control method based upon the hyperstability theory. The proposed control scheme has a simple sturcture is computationally fast and does not require knowledge of the complex dynamic model or the parameter values of the manipulator or the payload. Simulation results show that the proposed method not only improves the performance of the system but also reduces the chattering problem of sliding mode control, Consequently, it is expected that the new adaptive sliding mode control algorithm will be suited for various practical applications of industrial robot control system.

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Feasibility of Using an Automatic Lens Distortion Correction (ALDC) Camera in a Photogrammetric UAV System

  • Jeong, Hohyun;Ahn, Hoyong;Park, Jinwoo;Kim, Hyungwoo;Kim, Sangseok;Lee, Yangwon;Choi, Chuluong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.6
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    • pp.475-483
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    • 2015
  • This study examined the feasibility of using an automatic lens distortion correction (ALDC) camera as the payload for a photogrammetric unmanned aerial vehicle (UAV) system. First, lens distortion for the interior orientation (IO) parameters was estimated. Although previous studies have largely ignored decentering distortion, this study revealed that more than 50% of the distortion of the ALDC camera was caused by decentering distortion. Second, we compared the accuracy of bundle adjustment for camera calibration using three image types: raw imagery without the ALDC option; imagery corrected using lens profiles; and imagery with the ALDC option. The results of image triangulation, the digital terrain model (DTM), and the orthoimage using the IO parameters for the ALDC camera were similar to or slightly better than the results using self-calibration. These results confirm that the ALDC camera can be used in a photogrammetric UAV system using only self-calibration.

A Study on Kinematics Modeling and Motion Control Algorithm Development in Joint for Vertical Type Articulated Robot Arma (수직다관절형 아암의 운동학적 모델링 및 관절공간 모션제어에 관한 연구)

  • Jo, Sang-Young;Kim, Min-Seong;Yang, Jun-Seok;Won, Jong-Beom;Han, Sung-Hyun
    • Journal of the Korean Society of Industry Convergence
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    • v.19 no.1
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    • pp.18-30
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    • 2016
  • In this paper, we propose a new technique to the design and real-time control of an adaptive controller for robotic manipulator based on digital signal processors. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved Lyapunov second method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot manipulator with eight joints. joint space and cartesian space.

Zigbee based 1-ch ECG device with activity monitoring function (지그비를 기반으로 한 운동감시 기능을 가진 1채널 ECG장치 개발)

  • Hong, Joo-Hyun;Kim, Nam-Jin;Cha, Eun-Jong;Lee, Tae-Soo
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.41-43
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    • 2005
  • PDA-based monitoring is used to acquire continuously the patient's vital signs, including electrocardiography, activity, heart rate and $SpO_2$. In this paper, A biomedical signal acquisition device was designed using 3-axial MEMS accelerometer and 1-ch ECG amplifier, to have the function of monitoring activity and electrocardiography. The proposed system is composed of transmitter and receiver. Through the Zigbee communication, subject's biosignals can be transmitted in real-time to receiver, and transmitted data confirmed using PDA. The packet size used in this device was set not to exceed a maximum payload size of 116 byte. One packet consists of two segments. The transmission speed was 21 packet per second, 420 ECG samples per second, and 42 acceleration samples per second. The proposed method can be used to develop Activities of Daily Living(ADL} monitoring devices for the elderly or movement impaired people and enables patients to be monitored without any constraints. Also, this method will reduce medical costs in the aged society.

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A study on Real-Time Implementation of Robust Control for Horizontal Articulated Arm with Eight Axis

  • Nguyen, Hoo-Cong;Kim, Jun-Hong;Lee, Hee-Seop
    • Journal of the Korean Society of Industry Convergence
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    • v.18 no.3
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    • pp.139-149
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    • 2015
  • In this paper, we describe a new approach to perform real-time implementation of an robust controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for robot manipulator consisting of dual arm with eight degrees of freedom at the joint space and cartesian space.

A Study on Adaptive-Sliding Mode Control of SCARA Robot (스카라로보트의 적응-슬라이딩모드 제어에 관한 연구)

  • 윤대식
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.148-153
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    • 1999
  • In this paper, it is proposed the adaptive-sliding mode control technique which is new approach to implement the robust control of industrial robot manipulator with external disturbances and parameter uncertainties. Over the past decade, the design of advanced control systems for industrial robotic manipulators has been a very active area of research and two major design categories have emerged. Sliding mode control is a well-known technique for robust control of uncertain nonlinear systems. The robustness of sliding model controllers can be shown in continuous time, but digital implementation may not preserve robustness properties because the sampling process limits the existence of a true sliding mode. Adaptive control algorithm is designed by using the principle of the model reference adaptive control method based upon the hyperstability theory. The proposed control scheme has a simple structure is computationally fast and does not require knowledge of the complex dynamic model or the parameter values of the manipulator or the payload. Simulation results how that the proposed method not only improves the performance of the system but also reduces the chattering problem of sliding mode control. Consequently, it is expected that the new adaptive sliding mode control algorithm will be suited for various practical applications of industrial robot control system.

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