• Title/Summary/Keyword: complex signals

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The Design of a Real-Time Simulator on the Hydraulic Servo System

  • Chang, Sung-Ouk;Lee, Jin-Kul
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.1
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    • pp.9-14
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    • 2003
  • In this study we suggest real-time simulator that could describe rent system without ordinary DSP card. This simulator is composed of 80196kc-16bit ordinary microprocessor, which is widely used up to now and personal computer. DSP card that has calculated complex numerical equation is replaced 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 (80196kc) within sampling time in the closed loop system. This makes it possible to be described in hydraulic servo system in real time.

Nonlinear Modeling of Dynamic AFM Using Proper Orthogonal Modes (적합직교모드를 이용한 동적모드 AFM 의 비선형 모델링)

  • Hong, Sang-Hyuk;Lee, Soo-Il
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.379-382
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    • 2007
  • The proper orthogonal decomposition(POD) is used to the modal analysis of microcantilever of dynamic mode atomic force microscopy(AFM). The proper orthogonal modes(POM) are extracted from vibrating signals of microcantilever when it resonates and taps the sample. The POMs resemble the linear normal modes(LNM) of cantilever vibrating at each resonance frequency. Some of POMs in tapping microcantilever show quite different shapes from the POMs of the resonating microcantilever. Also this POMs can be applied to model for the complex nonlinear behavior of the dynamic mode AFM microcantilevers.

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ISO 26262 automotive functional safety: issues and challenges

  • Ismail, Azianti;Liu, Qiang
    • International Journal of Reliability and Applications
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    • v.15 no.2
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    • pp.151-161
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    • 2014
  • Recently, the automotive industry has been introduced to ISO 26262 in November 2011 to address the necessity of safety risk from sensor to actuator by providing guidance in the form of requirements and processes. The malfunctioning behaviour of these systems could have significant impact on the safety of humans and/or the environment. Most of the modern automobiles are equipped with embedded electronic systems which include lots of Electronic Controller Units (ECUs), electronic sensors, signals, bus systems and coding. Due to the complex application in electrical, electronics and programmable electronics, the need to carry out detailed safety analyses which focuses on the potential risk of malfunction is crucial for automotive systems. In this paper, the international trends on pre and post introduction of ISO 26262 through publications will be analyzed as well as to take a glimpse in the activities for implementing this standard by the automotive manufacturers. The issues and challenges which have been occurring from implementing this standard also will be highlighted.

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Time Series Simulation of Explosive Charges In Shallow Water Using Ray Approach

  • Hahn, Jooyoung;Lee, Seongwook;Na, Jungyul
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.3E
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    • pp.133-140
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    • 2003
  • A time series simulation is presented by a ray approach for the simulating the received waveform of a broadband acoustical signals interacting with the ocean boundaries. The environment is assumed to be horizontally stratified, and the seafloor is described in terms of homogeneous fluid half-space. The ray approach includes the effects of reflection from the air-water, water-sediment interface and phase shifts due to boundaries interaction. To generate time series, we assume that the acoustic energy propagates from source to receiver along eigenrays and represent the action of the bottom on the incident wave by a linear filter and characterized in the frequency domain by the transfer function. As example application, the time series for an explosive source in a shallow water environment is calculated and analyzed in terms of acoustical process. good agreement with measured time series is demonstrated.

Spinal Gap Junction Channels in Neuropathic Pain

  • Jeon, Young Hoon;Youn, Dong Ho
    • The Korean Journal of Pain
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    • v.28 no.4
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    • pp.231-235
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    • 2015
  • Damage to peripheral nerves or the spinal cord is often accompanied by neuropathic pain, which is a complex, chronic pain state. Increasing evidence indicates that alterations in the expression and activity of gap junction channels in the spinal cord are involved in the development of neuropathic pain. Thus, this review briefly summarizes evidence that regulation of the expression, coupling, and activity of spinal gap junction channels modulates pain signals in neuropathic pain states induced by peripheral nerve or spinal cord injury. We particularly focus on connexin 43 and pannexin 1 because their regulation vastly attenuates symptoms of neuropathic pain. We hope that the study of gap junction channels eventually leads to the development of a suitable treatment tool for patients with neuropathic pain.

A Change Point Detection of EEG Signal Based on the Eigenspace (고유 공간을 이용한 EEG의 특성 변화점 검출)

  • Kim, Ki-M.;Yoo, Sun-K.;Kim, Sun-H.;Song, Jae-S.;Kim, Nam-H.
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.11
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    • pp.117-120
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    • 1995
  • The electronencephalogram (EEG) is a complex electrical signal which reflects generalized brain activity. The EEG is utilized in the clinical assesment of many neurological and psychiatric disorders and offers promise for monitoring of patients undergoing operation. This paper describes a technique for quantitative analysis of EEG signals which is based on an eigenspace. Examples of the application approach to simulated and clinical EEG data illustrate the capabilities.

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A Study on Simple Adaptive Control of Flexible-Joint Robots Considering Motor Dynamics (모터 동역학식을 고려한 유연 연결 로봇의 간단한 적응 제어에 관한 연구)

  • Yoo, Sung-Jin;Choi, Yoon-Ho;Park, Jin-Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.11
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    • pp.1103-1109
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    • 2008
  • Since the flexible joint robots with motor dynamics are represented by the fifth-order nonlinear sγstem, it is difficult and complex to design the controller for electrically driven flexible-joint (EDFJ) robots. In this paper, we propose a simple adaptive control method to solve this problem. It is assumed that the model uncertainties of the robots dynamics, joint flexibility, and motor dynamics are unknown. For the simple control design, the dynamic surface design method is applied, and all uncertainties in the robot and motor dynamics are compensated by using the adaptive function approximation technique. It is proved that all signals in the controlled closed-loop system are uniformly ultimately bounded. Simulation results for three-link EDFJ manipulators are provided to validate the effectiveness of the proposed control system.

Radar Pulse Clustering using Kernel Density Window (커널 밀도 윈도우를 이용한 레이더 펄스 클러스터링)

  • Lee, Dong-Weon;Han, Jin-Woo;Lee, Won-Don
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.973-974
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    • 2008
  • As radar signal environments become denser and more complex, the capability of high-speed and accurate signal analysis is required for ES(Electronic warfare Support) system to identify individual radar signals at real-time. In this paper, we propose the new novel clustering algorithm of radar pulses to alleviate the load of signal analysis process and support reliable analysis. The proposed algorithm uses KDE(Kernel Density Estimation) and its CDF(Cumulative Distribution Function) to compose clusters considering the distribution characteristics of pulses. Simulation results show the good performance of the proposed clustering algorithm in clustering and classifying the emitters.

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An Artificial Life Model Based on Neural Networks for Navigation of Multiple Autonomous Mobile Robots in the Dynamic Environment (동적 환경에서 자율 이동 로봇군의 이동을 위한 신경 회로망 기반 인공 생명 모델)

  • Min, Seok-Ki;Kang, Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.2
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    • pp.180-188
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    • 1999
  • The objective of this paper is, based upon the principles of artificial life, to induce emergent behaviors of multiple autonomous mobile robots which complex global intelligence form from simple local interactions. Here, we propose an architecture of neural network learning with reinforcement signals which perceives the neighborhood information and decides the direction and the velocity of movement as mobile robots navigate in a group. As the results of the simulations, the optimum weight is obtained in real time, which not only prevent the collisions between agents and obstacles in the dynamic environment, but also have the mobile robots move and keep in various patterns.

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Construction and roles of computer simulator for digital controller design

  • Nakamura, Masatoshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.909-914
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    • 1988
  • The structure of a digital controller based on modern control theory is more complex than that of a PID controller. In implementing the digital control of an actual system by using the digital controller, we often encounter gaps between theory and practice e.g. quantization error, sampling error, modeling error, contaminated noise etc. In such cases, simulator plays an important role in detecting difficulties. This paper demonstrates the importance of the computer simulator for designing a digital controller. The controller and the simulator are constructed by different computer respectively, with a link between the blocks by analogue signals through the A/D, D/A converters. Through the simulator test, we can evaluate the digital controller; identify and solve difficulties in the digital control. The controller, which pasted the simulator test, is used identically in the actual system. This was a successful procedure for designing the controller. As an example, we successfully constructed the digital controller using the computer simulator for inverted pendulum control. We then compared the control results of simulator and actual equipment. Furthermore we commented on the construction of the computer simulator which exactly expressed the actual system.

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