• Title/Summary/Keyword: Peak estimation

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Indicated and Load Torque Estimation of SI-Engine using Cylinder Pressure Sensor (실린더 압력센서를 사용한 가솔린 엔진의 도시토크와 부하토크의 추정)

  • 백종탁;박승범;선우명호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.1-6
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    • 2003
  • The torque is an important measure that represents the performance of a particular engine. Furthermore the information of engine torque can be used as a primary feedback parameter in modem engine management system. In this paper, a methodology is proposed for torque estimation of SI-engine. Since the proposed method uses cylinder pressure sensor, the torque can be estimated in a simple manner. The indicated torque is estimated from the peak pressure and its location, and the load torque is observed by the state observer based on the estimated indicated torque. The proposed method is accurate and robust against the variations that affect the torque production such as spark timing, mass air flow and others. This torque estimation method may be an alternative solution to the use of engine torque maps in a modem torque-based engine management system.

A Study on method development of parameter estimation for real-time QRS detection (실시간 QRS 검출을 위한 파라미터 estimation 기법에 관한 연구)

  • Kim, Eung-Suk;Lee, Jeong-Whan;Yoon, Ji-Young;Lee, Myoung-Ho
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.11
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    • pp.193-196
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    • 1995
  • An algorithm using topological mapping has been developed for a real-time detection of the QRS complexes of ECG signals. As a measurement of QRS complex energy, we used topological mapping from one dimensional sampled ECG signals to two dimensional vectors. These vectors are reconstructed with the sampled ECG signals and the delayed ones. In this method, the detection rates of CRS complex vary with the parameters such as R-R interval average and peak detection threshold coefficient. We use mean, median, and iterative method to determint R-R interval average and peak estimation. We experiment on various value of search back coefficient and peak detection threshold coefficient to find optimal rule.

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Performance Evaluation of The Weighted TR Prefilter with Channel Estimation Error in An Indoor Wireless Communication Environment (실내 무선 통신 환경에서 채널 추정 에러에 따른 가중치를 부여한 시역전 필터의 성능 평가)

  • Yoon, Misun;Lee, Chungyong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.8
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    • pp.76-82
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    • 2013
  • We evaluate the performance of the time-reversal (TR) prefilter and the weighted TR prefilter in an indoor wireless communication system with channel estimation errors. The TR prefilter uses a time-reversed channel as a prefilter to maximize received peak power. The equivalent channel of the TR prefilter is an 공분산 of the channel and the received peak power is maximized. When there are channel estimation errors, the equivalent channel is not an 공분산 of the channel and the received peak power cannot be maximized. The weighted TR prefilter minimizes the inter-symbol interference and maintains the received peak power. Thus, even when there are some channel estimation errors, the weighted TR prefilter can guarantee the received peak power.

A Fast Parameter Estimation of Time Series Data Using Discrete Fourier Transform (이산푸리에변환과 시계열데이터의 고속 파라미터 추정)

  • Shim, Kwan-Shik;Nam, Hae-Kon
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.7
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    • pp.265-272
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    • 2006
  • This paper describes a method of parameter estimation of time series data using discrete Fourier transform(DFT). DFT have been mainly used to precisely and rapidly obtain the frequency of a signal. In a dynamic system, a real part of a mode used to learn damping characteristics is a more important factor than the frequency of the mode. The parameter estimation method of this paper can directly estimate modes and parameters, indicating the characteristics of a dynamic system, on the basis of the Fourier transform of the time series data. Real part of a mode estimates by subtracting a frequency of the Fourier spectrum corresponding to 0.707 of a magnitude of the peak spectrum from a peak frequency, or subtracting a frequency of the power spectrum corresponding to 0.5 of the peak power spectrum from a peak frequency, or comparing the Fourier(power) spectrum ratio. Also, the residue and phase of time signal calculate by simple equation with the real part of the mode and the power spectrum that have been calculated. Accordingly, the proposed algorithm is advantageous in that it can estimate parameters of the system through a single DFT without repeatedly calculating a DFT, thus shortening the time required to estimate the parameters.

Enhanced Maximum Voiced Frequency Estimation Scheme for HTS Using Two-Band Excitation Model

  • Park, Jihoon;Hahn, Minsoo
    • ETRI Journal
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    • v.37 no.6
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    • pp.1211-1219
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    • 2015
  • In a hidden Markov model-based speech synthesis system using a two-band excitation model, a maximum voiced frequency (MVF) is the most important feature as an excitation parameter because the synthetic speech quality depends on the MVF. This paper proposes an enhanced MVF estimation scheme based on a peak picking method. In the proposed scheme, both local peaks and peak lobes are picked from the spectrum of a linear predictive residual signal. The average of the normalized distances of local peaks and peak lobes is calculated and utilized as a feature to estimate an MVF. Experimental results of both objective and subjective tests show that the proposed scheme improves the synthetic speech quality compared with that of a conventional one in a mobile device as well as a PC environment.

An Iterative MUSIC-Based DOA Estimation System Using Antenna Direction Control for GNSS Interference

  • Seo, Seungwoo;Park, Youngbum;Song, Kiwon
    • Journal of Positioning, Navigation, and Timing
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    • v.9 no.4
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    • pp.367-378
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    • 2020
  • This paper introduces the development of the iterative multiple signal classification (MUSIC)-based direction-of-arrival (DOA) estimation system using a rotator that can control the direction of antenna for the global navigation satellite system (GNSS) interference. The system calculates the spatial spectrum according to the noise eigenvector of all dimensions to measure the number of signals (NOS). Also, to detect the false peak, the system adjusts the array antenna's direction and checks the change's peak angles. The phase delay and gain correction values for system calibration are calculated in consideration of the chamber's structure and the characteristics of radio waves. The developed system estimated DOAs of interferences located about 1km away. The field test results show that the developed system can estimate the DOA without NOS information and detect the false peak even though the inter-element spacing is longer than the half-wavelength of the interference.

Fast Estimation of Low Frequency Parameter for Real-Time Analysis in Wide Area Systems (광역계통의 실시간해석을 위한 고속 저주파수 파라미터 추정)

  • Kim, Eun-Ju;Shim, Kwan-Shik;Kim, Yong-Gu;Kim, Eui-Sun;Nam, Hae-Kon;Lim, Young-Chul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.6
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    • pp.1078-1086
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    • 2009
  • This paper presents a Fourier based algorithm for estimating the parameters of the low frequency oscillating modes. The proposed methods estimates various parameters(frequency, damping factor, mode magnitude, phase) by fitting Fourier spectrum and phase with a damped exponential cosine function. Dominant frequency is selected by taking frequency corresponding to the peak spectrum, and damping factor is estimated using the left/right spectra of Fourier spectrum. In addition, mode magnitude is calculated by the normalized peak spectrum, and phase is estimated from spectrum phase. Also, we introduce an accuracy index in order to determine the accuracy of the estimated parameters, and the index is calculated using the deviations of the peak spectrum and the left/right spectra. The parameter estimation methods proposed in this paper include very simple arithmetical processes, so the algorithms are simple and the calculation speed is very fast. The proposed methods are applied to test functions with two dominant modes. The results show that the proposed methods are highly applicable to low frequency parameter estimation.

An Estimation method for Characteristic Parameters in a Low Frequency Signal Transformed by High Frequency Signals (고주파 신호에 의하여 변형된 저주파신호에서의 특성변수 추정 기법)

  • Yoo, Kyung-Yul
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.2
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    • pp.86-88
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    • 2002
  • An estimation method for the characteristic parameters in the low frequency signal is proposed in this paper. A low frequency signal is assumed to be modulated or distorted by high frequency terms. The algorithm proposed in this paper is designed to select set of local maximums in a successive manner, hence it is denoted as the iterative peak picking(IPP) algorithm. The IPP algorithm is operating in the time domain and is using only the comparison operation between two neighboring samples. Therefore, its computational complexity is very low and the delay caused by the computation is negligible, which make the real-time operation possible with economic hardware. The proposed algorithm is verified on the pitch estimation of speech signal and blood pulse estimation.

The Analysis of 2004 Summer Peak Load in Korea Power system (2004년 하계 첨두부하 시 계통운영 실적 분석)

  • Song, Tae-Yong;Hwang, Bong-Hwan
    • Proceedings of the KIEE Conference
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    • 2004.11b
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    • pp.113-115
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    • 2004
  • This year korea power system had recorded highest peak load for 6 times and finally it made new peak load 51,264MW at July 29th 3:00 PM. The new peak load is increased 8.2% from the last year peak load 47,385MW and korea power system entered 50,000MW load era. The Korea Power Exchange (KPX) snapped power system data at the peak load time using state estimation function in the EMS. And authors converted the power system data at peak load to PSS/E power flow format. Using this PSS/E peak load power flow data, this paper explains demand analysis result shun capacitor operation, voltage distribution at the peak load. And the paper shows the simulation result of 2 contingency analysis using the snapped PSS/E peak load data.

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A search-based high resolution frequency estimation providing improved convergence characteristics in power system (전력계통에서 수렴성 향상을 위한 탐색기반 고분해능 주파수 추정기법)

  • An, Gi-Sung;Seo, Young-Duk;Chang, Tae-Gyu;Kang, Sang-Hee
    • Journal of IKEEE
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    • v.22 no.4
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    • pp.999-1005
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    • 2018
  • This paper proposed a search-based high resolution frequency estimation method in power systme. The proposed frequency estimation method adopts a slope-based adaptive search as a base of adaptive estimation structure. The architectural and operational parameters in this adaptive algorithm are changed using the information from context layer analysis of the signals including a localized full-search of spectral peak. The convergence rate of the proposed algorithm becomes much faster than those of other conventional slope-based adaptive algorithms by effectively reducing search range with the application of the localized full-search of spectrum peak. The improvements in accuracy and convergence rate of the proposed algorithm are confirmed through the performance comparison with other representative frequency estimation methods, such as, DFT(discrete Fourier transform) method, ECKF(extended complex Kalman filter), and MV(minimum variable) method.