Effective algorithms for measuring frequency and phase difference in real time

A new signal processing method for phase difference estimation was proposed based on time-varying signal model, whose frequency, amplitude and phase are time-varying. And then be applied Coriolis mass flowmeter signal. First, a bandpass filtering FIR filter was applied to filter the sensor output signal in order to improve SNR. Then, the signal frequency could be calculated based on short-time frequency estimation. Finally, by short window intercepting, the DTFT algorithm with negative frequency contribution was introduced to calculate the real-time phase difference between two enhanced signals. With the frequency and the phase difference obtained, the time interval of two signals was calculated. Simulation results show that the algorithms studied are efficient. Furthermore, the computation of algorithms studied is simple so that it can be applied to real-time signal processing for Coriolis mass flowmeter.

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Multiple Phase Difference Method for Real-Time SAR Autofocus

Journal of Electromagnetic Waves and Applications ◽

10.1163/156939306775701713 ◽

2006 ◽

Vol 20 (3) ◽

pp. 375-388 ◽

Cited By ~ 7

Author(s):

V. C. Koo ◽

Y. K. Chan ◽

H. T. Chuah

Keyword(s):

Real Time ◽

Phase Difference ◽

Difference Method ◽

Multiple Phase

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Research of Magnetic Grid Rail Splicing Technology Based on Phase Difference Detection Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.278-280.905 ◽

2013 ◽

Vol 278-280 ◽

pp. 905-914

Author(s):

Wen Tao Gu ◽

Shao Kun Lei ◽

Fang Li ◽

Shao Wei Zhou

Keyword(s):

Real Time ◽

Phase Difference ◽

Detection Algorithm ◽

Initial Position ◽

Signal Frequency ◽

Simulation Test ◽

Signal Phase ◽

Difference Detection ◽

Phase Errors ◽

New Type

To meet the high real-time performance and high accuracy requirements of signal detection in the rail splicing process, this paper proposes a new type of magnetic grid rail splicing method based on accurately zeroing output signal phase difference of two magnetic grid reading heads, thus establishing two reading heads “shift” rules. The accurate zero setting technology of phase difference is based on Nuttall window algorithm, which doesn’t need to give the exact signal frequency beforehand and sample periodically, and can effectively eliminate phase errors. So this algorithm is suitable for detecting signal phase difference when reading heads go over buff joints with any speed at any initial position. Additionally, simulation test and experimental verification were performed on this detection algorithm and “shift” rules. The results show that, the method mentioned in this paper can real-time detect the phase difference by “shift” rules, when reading heads go over buff joints with any speed or any acceleration.

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Phase-Difference Compensation and Nonuniform Pulse Transmission for Accurate Real-Time Moving Object Tracking

IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences ◽

10.1587/transfun.e102.a.211 ◽

2019 ◽

Vol E102.A (1) ◽

pp. 211-218

Author(s):

Koichi ICHIGE ◽

Nobuya ARAKAWA ◽

Ryo SAITO ◽

Osamu SHIBATA

Keyword(s):

Object Tracking ◽

Real Time ◽

Phase Difference ◽

Moving Object ◽

Pulse Transmission ◽

Moving Object Tracking

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Real time High Accuracy Phase Difference Measurement for Parallel Multi-Channel Sensors

2019 International SoC Design Conference (ISOCC) ◽

10.1109/isocc47750.2019.9078502 ◽

2019 ◽

Author(s):

Muhammad Riaz ur Rehman ◽

Imran Ali ◽

Pervesh Kumar ◽

SungJin Kim ◽

Kang-Yoon Lee

Keyword(s):

Real Time ◽

Phase Difference ◽

High Accuracy ◽

Difference Measurement

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A Real-Time Automated System for Dual-Aperture Common-Path Interferometer Phase-Shifting

Applied Sciences ◽

10.3390/app11167438 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7438

Author(s):

Antonio Barcelata-Pinzón ◽

Ricardo Iván Álvarez-Tamayo ◽

Patricia Prieto-Cortés

Keyword(s):

Real Time ◽

Phase Difference ◽

Low Cost ◽

Analytical Calculation ◽

Ccd Camera ◽

Phase Shifting ◽

Automated System ◽

Common Path ◽

Interferometer Phase ◽

Phase Differences

We report a novel fully real-time automatized optomechatronic dual-aperture common-path interferometer system for obtaining the phase difference between two interferograms by using the technique of phase-shifting interferometry. A motorized system is used to shift an additional phase transversally to the optical axis by ruling translation. For each high-resolution ruling displacement step of 0.793 μm, an interferogram is recorded by a CCD camera. The phase difference between the two successive recorded interferograms is then automatically calculated by computational self-calibrated algorithms. The proposed device provides more accurate measuring than typically used manual processes. Real-time phase differences are obtained from a robust low-cost optomechatronic system. Analytical calculation of the phase is performed automatically without the requirement of additional or external tools and processes, reducing the significant rework delay. A set of 47 interferograms were captured in real time then recorded and analyzed, obtaining an average phase shifting of 2.483 rad. Analytic explanation and experimental results are presented.

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