• 제목/요약/키워드: interpolation error

검색결과 504건 처리시간 0.03초

Tracking Error Extraction Algorithm in Monopulse Active Homing Radar System

  • Kwon, Jun-Beom;Kim, Do-Hyun;Kim, Lee-Han;Byun, Young-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.158.5-158
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    • 2001
  • Monopulse active homing radar requires velocity and angle information of target to track fast moving target. Target velocity can be estimated by measuring the frequency shift between transmitted and received frequencies. Angle information is obtained by measuring boresight error. Measurement of doppler frequency component in received signal is done through FFT analysis and interpolation algorithm for fine tuning. Boresight errors in azimuth and elevation axes are proportional to the power of each difference channel relative to sum channel. The target signal power in difference channel is estimated more precisely by measuring the power of FFT result cell of maximum ...

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Velocity profile generation methods for industrial robots and CNC machine tools

  • Kim, Dong-Il;Song, Jin-Il;Kim, Sungkwun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.306-311
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    • 1992
  • We propose software algorithms which provide the characteristics of acceleration/deceleration essential to high dynamic performance at the transient state where industrial robots or CNC machine tools start and stop. The path error, which is one of the most significant factors in performance evaluation of industrial robots and CNC machine tools, is analyzed for linear, exponential, and parabolic acceleration/deceleration algorithms in case of circular interpolation. The analysis shows that the path error depends on the acceleration/deceleration routine and the servo control system. In experiments, the entire control algorithm including the proposed acceleration/deceleration algorithms is executed on the motion control system with a floating point digital signal processor(DSP) TMS320C30 as a CPU. The experimental results demonstrate that the proposed algorithms are very effective in controlling axes of motion of industrial robots or CNC machine tools with the desired characteristics.

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Sub-micron Control Algorithm for Grinding and Polishing Aspherical Surface

  • Kim, Hyung-Tae;Yang, Hae-Jeong;Kim, Sung-Chul
    • International Journal of Control, Automation, and Systems
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    • 제6권3호
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    • pp.386-393
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    • 2008
  • A position control method for interpolating aspherical grinding and polishing tool path was reviewed and experimented in a nano precision machine. The position-base algorithm was reformed from the time-base algorithm, proposed in the previous study. The characteristics of the algorithm were in the velocity control loop with position feedback. The aspherical surface was divided by an interval at which each velocity and acceleration were calculated. The theoretical velocity was corrected by position error during processing. In the experiment, a machine was constructed and nano-scale linear encoders were installed at each axis. Relation between process parameters and the variation of position error was monitored and discussed. The best result from optimized parameters showed that the accuracy was 150nm and improved from the previous report.

퍼지 슬라이딩 모드 제어기 및 신경망 보간기를 이용한 Underwater Flight Vehicle의 심도 제어 (Depth Control of Underwater Flight Vehicle Using Fuzzy Sliding Mode Controller and Neural Network Interpolator)

  • 김현식;박진현;최영규
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권8호
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    • pp.367-375
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    • 2001
  • In Underwater Flight Vehicle depth control system, the followings must be required. First, it needs robust performance which can get over modeling error, parameter variation and disturbance. Second, it needs accurate performance which have small overshoot phenomenon and steady state error to avoid colliding with ground surface or obstacles. Third, it needs continuous control input to reduce the acoustic noise and propulsion energy consumption. Finally, it needs interpolation method which can sole the speed dependency problem of controller parameters. To solve these problems, we propose a depth control method using Fuzzy Sliding Mode Controller with feedforward control-plane bias term and Neural Network Interpolator. Simulation results show the proposed method has robust and accurate control performance by the continuous control input and has no speed dependency problem.

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Sub-pixel image interpolations for PIV

  • Kim Byoung Jae;Sung Hyung Jin
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
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    • pp.47-55
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    • 2004
  • Several interpolations for image deformation in PIV were evaluated. The tested interpolation methods are linear, quadratic, truncated sinc, windowed sinc, cubic, Lagrange, Gaussian $2^{nd}\;and\;6^{th}$ interpolators. Bias errors and random errors were evaluated in the range of $0\~3.0$ pixel uniform displacement using synthetic images. We also measured the time cost of each interpolator with respect to kernel size. The cubic interpolator with $6\times6$ kernel showed the best results in terms of the performance and time cost.

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FMCW 레이더의 거리 및 속도 오차 향상을 위한 신호처리부 하드웨어 구조 제안 (Architecture of Signal Processing Unit to Improve Range and Velocity Error for Automotive FMCW Radar)

  • 현유진;이종훈
    • 한국자동차공학회논문집
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    • 제18권4호
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    • pp.54-61
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    • 2010
  • In this paper, we design the signal processing unit to effectively support the proposed algorithm for an automotive Frequency Modulation Continuous Wave(FMCW) radar. In the proposed method, we can obtain the distance and velocity with improved error depending on each range(long, middle, and short) of the target. Since a high computational capacity is required to obtain more accurate distance and velocity for target in near range, the proposed signal processing unit employs the time de-interleaving and the frequency interpolation method to overcome the limitation. Moreover, for real-time signal processing, the parallel architecture is used to extract simultaneously the distance and velocity in each range.

Study on gesture recognition based on IIDTW algorithm

  • Tian, Pei;Chen, Guozhen;Li, Nianfeng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권12호
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    • pp.6063-6079
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    • 2019
  • When the length of sampling data sequence is too large, the method of gesture recognition based on traditional Dynamic Time Warping (DTW) algorithm will lead to too long calculation time, and the accuracy of recognition result is not high.Support vector machine (SVM) has some shortcomings in precision, Edit Distance on Real Sequences(EDR) algorithm does not guarantee that noise suppression will not suppress effective data.A new method based on Improved Interpolation Dynamic Time Warping (IIDTW)algorithm is proposed to improve the efficiency of gesture recognition and the accuracy of gesture recognition. The results show that the computational efficiency of IIDTW algorithm is more than twice that of SVM-DTW algorithm, the error acceptance rate is FAR reduced by 0.01%, and the error rejection rate FRR is reduced by 0.5%.Gesture recognition based on IIDTW algorithm can achieve better recognition status. If it is applied to unlock mobile phone, it is expected to become a new generation of unlock mode.

A Temporal Error Concealment based on Motion Vector Recovery for H.264/AVC

  • Wu, Jun;Liu, Xingang;Yoo, Kook-Yeol
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2007년도 춘계학술발표대회
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    • pp.341-344
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    • 2007
  • In this paper, a new temporal error concealment method for the new coding standard H.264/AVC is presented, which uses the high correlation between the motion vectors of neighboring blocks. By using the motion vector of neighboring MB of the lost MB, the MV of the lost MB are recovered. It is shown that under FMO coding method of H.264/AVC, the proposed method increases PSNR gain up to 2.85dB compared to build-in algorithm in the H.264/AVC test model and 2.59dB compared to Lagrange interpolation.

TOPMODEL과 Muskingum 기법을 연계한 안성천 유역의 홍수유출 분석 (Flood Runoff Analysis using TOPMODEL Linked with Muskingum Method - Anseong-cheon Watershed -)

  • 권형중;김성준
    • 한국지리정보학회지
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    • 제6권1호
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    • pp.1-11
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    • 2003
  • 본 연구는 안성천 유역($581.7km^2$)을 대상으로 TOPMODEL 분포형 수문모형에 Muskingum 하도 추적기법을 연계하여 유출분석을 수행하였다. 유역의 하류에 분포하고 있는 평야부에 대해서는 linear trend surface interpolation 기법을 사용하여 상류에서 하류방향으로 DEM을 평활화하는 방법으로 평야부의 흐름방향을 부여하였다. TOPMODEL 적용시 지형지표인자의 분포 및 빈도를 추출하기 위하여 MFD(multiple flow direction) 알고리즘을 이용하였다. 중규모 이상의 유역을 대상으로 TOPMODEL을 적용할 경우 DEM의 해상도 저하가 모형의 결과에 영향을 미치게 되므로, 그 해결방안으로서 전체유역을 소유역으로 분할하여 DEM의 해상도를 유지시키고, 소유역간의 결과는 Muskinguim 하도추적기법으로 전달되도록 하였다. 전체유역을 대상으로 500m 해상도로 TOPMODEL을 적용한 유출모의 결과 27.2%의 상대오차를 보인 반면, 유역을 2개의 소유역으로 나누어 300m 및 350m의 공간해상도로 TOPMODEL과 Muskingum 기법을 병행하여 적용한 결과 상대오차가 15.8%로 나타나, 모형의 효율이 증가하는 것을 확인할 수 있었다.

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Zoom FFT를 이용한 정밀 레벨 측정 장치의 구현 (Implementation of Precise Level Measurement Device using Zoom FFT)

  • 지석준;이준탁
    • Journal of Advanced Marine Engineering and Technology
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    • 제36권4호
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    • pp.504-511
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    • 2012
  • 본 연구에서는 FMCW타입의 레이더 레벨 트랜스미터의 송 수신 신호간 주파수 차인 비트 주파수를 이용한 레벨 측정 장치를 구현하고자 한다. 레벨 정보를 나타내는 비트 주파수는 FFT(Fast Fourier Transform)과정을 통해 해석되며, 주파수 정밀도를 향상시키기 위해 Zoom FFT 기법을 적용하였다. Zoom FFT는 신호 처리 장치의 설계 초기에 결정되는 샘플링 주파수나 샘플링 데이터 수를 변경하지 않고도 주파수 분해능을 개선할 수 있는 장점을 가지며, Zoom FFT를 적용함으로써 146.5[mm]이던 거리 분해능을 5[mm]의 거리 분해능으로 크게 개선하였다. 또한, 스플라인 보간법을 활용하여 FFT point 수를 늘임으로써 레벨 측정 오차를 개선할 수 있었다. Zoom FFT를 적용한 거리 측정 방식의 유효성을 검증하기 위하여 1[mm] 단위로 거리 조정이 가능한 실험 장치를 제작하였으며, 실험을 통해 700~2,000[mm]의 거리에서 ${\pm}2$[mm] 이내의 측정 오차로 정밀 측정이 가능함을 확인하였다.