• Title/Summary/Keyword: digital signal process

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Implementation of Real-Time Fuzzy Controller for SCARA Type Dual-Arm Robot (스카라형 이중 아암 로봇의 실시간 퍼지제어기 실현)

  • Kim Hong-Rae;Han Sung-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.12
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    • pp.1223-1232
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    • 2004
  • We present a new technique to the design and real-time implementation of fuzzy control system basedon digital signal processors in order to improve the precision and robustness for system of industrial robot in this paper. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The TMS320C80 is used in implementing real time fuzzy control to provide an enhanced motion control for robot manipulators. In this paper, a Self-Organizing Fuzzy Controller for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variables of the controller. In the synthesis of a Fuzzy Logic Controller, one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult Self-Organizing Fuzzy Controller is proposed for a hierarchical control structure consisting of basic and high levels that modify control rules. The proposed Self-Organizing Fuzzy Controller scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Performance of the SOFC is illustrated by simulation and experimental results for a Dual-Arm robot with eight joints.

A Low-power High-resolution Band-pass Sigma-delta ADC for Accelerometer Applications

  • Cao, Tianlin;Han, Yan;Zhang, Shifeng;Cheung, Ray C.C.;Chen, Yaya
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.3
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    • pp.438-445
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    • 2017
  • This paper presents a low-power high-resolution band-pass ${\Sigma}{\Delta}$ ADC for accelerometer applications. The proposed band-pass ${\Sigma}{\Delta}$ ADC consists of a high-performance 6-th order feed-forward ${\Sigma}{\Delta}$ modulator with 1-bit quantization and a low-power, area-efficient digital filter. The ADC is fabricated in 180 nm 1P6M mixed-signal CMOS process with a die area of $5mm^2$. This high-resolution ADC got 90 dB peak signal to noise plus distortion ratio (SNDR) and 96 dB dynamic range (DR) over 4 kHz bandwidth, while the intermediate frequency (IF) is shifting from 100 KHz to 200 KHz. The power dissipation of the chip is 5.6 mW under 1.8 V (digital)/3.3 V (analog) power supply.

Implementation of FBG Sensor Network System for Monitoring Structure Deformation (구조물 변형 모니터링을 위한 FBG센서 네트워크 시스템 구현)

  • Park, Jang-Sik;Park, Keun-Soo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.8
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    • pp.841-846
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    • 2014
  • FBG sensors are mainly used to measure deformation of structures such as tunnels, bridges and ships. In this paper, an interrogator of FBG sensors is developed and implemented to measure the status of structures. A developed interrogator includes CAN wired and Zigbee wireless communication for remote monitoring. Strain of structure is measured using shift of wavelength of reflected light from FBG sensor. A digital signal controller is used to process signals of a FBG sensor and transmit data for remote monitoring. As a result of experiment, developed interrogator is effective to measure deformation of structures.

A Study on Embedded DSP Implementation of Keyword-Spotting System using Call-Command (호출 명령어 방식 핵심어 검출 시스템의 임베디드 DSP 구현에 관한 연구)

  • Song, Ki-Chang;Kang, Chul-Ho
    • Journal of Korea Multimedia Society
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    • v.13 no.9
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    • pp.1322-1328
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    • 2010
  • Recently, keyword spotting system is greatly in the limelight as UI(User Interface) technology of ubiquitous home network system. Keyword spotting system is vulnerable to non-stationary noises such as TV, radio, dialogue. Especially, speech recognition rate goes down drastically under the embedded DSP(Digital Signal Processor) environments because it is relatively low in the computational capability to process input speech in real-time. In this paper, we propose a new keyword spotting system using the call-command method, which is consisted of small number of recognition networks. We select the call-command such as 'narae', 'home manager' and compose the small network as a token which is consisted of silence with the noise and call commands to carry the real-time recognition continuously for input speeches.

Sigma-Delta Modulator using a novel FDPA(Feedback Delay Path Addition) Technique (새로운 FDPA 기법을 사용한 시그마-델타 변조기)

  • Jung, Eui-Hoon;Kim, Jae-Bung;Cho, Seong-Ik
    • Journal of IKEEE
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    • v.17 no.4
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    • pp.511-516
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    • 2013
  • This paper presents a SDM using the FDPA technique. The FDPA technique is the added feedback path which is the delayed path of DAC output. The designed SDM increases the SNR by adding the delayed digital feedback path. The proposed SDM is easily implemented by eliminating the analog feedback path. Through the MATLAB modeling, the optimized coefficients are obtained to design the SDM. The designed SDM has a power consumption of $220{\mu}W$ and SNR(signal to noise ratio) of 81dB at the signal-bandwidth of 20KHz and sampling frequency of 2.56MHz. The SDM is designed using the $0.18{\mu}m$ standard CMOS process.

Exploiting Correlation Characteristics to Detect Covert digital communication

  • Huang, Shuhua;Liu, Weiwei;Liu, Guangjie;Dai, Yuewei;Tian, Wen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.8
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    • pp.3550-3566
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    • 2020
  • As a widely used way to exfiltrate information, wireless covert channel (WCC) brings a serious threat to communication security, which enables the wireless communication process to bypass the authorized access control mechanism to disclose information. Unlike the covert channel on the network layer, wireless covert channels on the physical layer (WCC-P) is a new covert communication mode to implement and improve covert wireless communication. Existing WCC-P scheme modulates the secret message bits into the Gaussian noise, which is also called covert digital communication system based on the joint normal distribution (CJND). Finding the existence of this type of covert channel remains a challenging work due to its high undetectability. In this paper, we exploit the square autocorrelation coefficient (SAC) characteristic of the CJND signal to distinguish the covert communication from legitimate communication. We study the sharp increase of the SAC value when the offset is equal to the symbol length, which is caused by embedding secret information. Then, the SAC value of the measured sample is compared with the threshold value to determine whether the measured sample is CJND sample. When the signal-to-noise ratio reaches 20db, the detection accuracy can reach more than 90%.

A Study on the Application of the Real-Time Simulator (실시간 모의시험기의 적용에 관한 연구)

  • 장성욱;이진걸
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.191-191
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    • 2000
  • Hydraulic servo system is difficult to be made up and each component is very expensive, it takes long for actual system to make and test and it costs a high price. Because of these characteristics of hydraulic servo system, a real time simulator that could describe behavior of real system is highly demanded, without composing real hydraulic system. So, many studies have been (lone on these subjects and many simulators are developed with superiority. Since the nonlinearity of a hydraulic system common simulator have composed of many calculative times byusing DSP(Digital Signal processing) and have made it possible to find the situations of the system in real time, calculating hydraulic simulation and controller separately. In this study, we suggest real-time simulator that could describe real system without ordinary DSP card. This simulator is composed of 80196kc and personal computer. DSP card that has calculated complex numerical equation is supplanted by personal computer and 80196kc generates control signals independently out of the personal computer. In all process, personal computer is synchronized with one-board microprocessor within sampling time in the closed loop system. This makes it possible to be described in hydraulic servo system in real time. And to make a comparison between the result of the real-time simulator and a hydraulic servo system.

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FPGA-DSP Based Implementation of Lane and Vehicle Detection (FPGA와 DSP를 이용한 실시간 차선 및 차량인식 시스템 구현)

  • Kim, Il-Ho;Kim, Gyeong-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.12C
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    • pp.727-737
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    • 2011
  • This paper presents an implementation scheme of real-time lane and vehicle detection system with FPGA and DSP. In this type of implementation, defining the functionality of each device in efficient manner is of crucial importance. The FPGA is in charge of extracting features from input image sequences in reduced form, and the features are provided to the DSP so that tracking lanes and vehicles are performed based on them. In addition, a way of seamless interconnection between those devices is presented. The experimental results show that the system is able to process at least 15 frames per second for video image sequences with size of $640{\times}480$.

De-noising Method using Nonlinear Filter Algorithm in Mixed Noise Environments (복합잡음 환경에서 비선형 필터 알고리즘을 이용한 잡음제거 방법)

  • Long, Xu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.9
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    • pp.2265-2271
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    • 2014
  • In modern society digital equipments that are related with various hardware and software are popularized, and digital images are widely applied in the field of production and scientific research. In general, however, images are degraded by the noise in the process of transmission and storage. In this paper, to reduce the influence of mixed noises, the algorithm in which noises in the space area are classified into impulse noise and Gaussian noise and this is processed by applying weighted value, while that is processed by modified nonlinear filter is proposed. And the excellence of the proposed algorithm is judged by PSNR(peak signal to noise ratio).

A Study on Modified Median Filter Algorithm for Degraded Image of Impulse Noise (임펄스 잡음에 훼손된 영상을 위한 변형된 메디안 필터 알고리즘에 관한 연구)

  • Hong, Sang-Woo;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.798-800
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    • 2014
  • In recent years, according to the improvement of Digital image technology have been recently developed most of communication technology from multimedia communication service as well as image data transmission. But In the process of storing and transmitting noise is still generated in noise and the image degrades rapidly quality of a lot of image impulse noise. To eliminate this noise, SMF, CWMF, SWMF etc. The filters have been proposed to interfere with the noise characteristics of the filter are somewhat sufficient. Therefore, in this paper, in order to remove impulse noise is proposed a modified median filter. And impulse noise removal algorithms to confirm the existed PSNR(peak signal to noise ratio) from using conventional methods were compared.

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