Nanodisplacement Measurements of Piezoelectric Flextensional Actuators Using a New Interferometry Homodyne Method

-Optical voltage sensors are widely used for HighVoltage (HV) sensing but measurement accuracy is often compromised by sensitivity drift due to variations in the ambient conditions. Synthetic-heterodyne demodulation is a useful technique for dynamic displacement measurements using interferometric sensors as it can provide a detected signal that is immune to interferometric drift. In this paper a new syntheticheterodyne technique, employing the Hilbert transform and gain control feedback, is applied to a polarimetric based optical sensor system and used to measure a HV signal. The system comprises a He-Ne laser source, optical phase modulator and HV sensor located between two polarizers followed by a photodetector and real-time electrical signal acquisition and processing. The use of a control loop results in significant improvements in the stability and accuracy of the detected HV signal. The sensor system was used to measure a 60 Hz HV signal with an amplitude range of 300 V to 7.5 kV. The sensor was also used to successfully measure the total power line harmonic distortion of a highly distorted 4 kV signal. The experimental results show very good agreement with measurements obtained by using the industry standard signal coincidence method.

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“…If the AAF frequency response is considered, the correct form of (6) and (10) can be expressed as (15) and (16) …”

Section: Gain Feedback Controlmentioning

confidence: 99%

Polarimetric Optical High-Voltage Sensor Using Synthetic-Heterodyne Demodulation and Hilbert Transform With Gain Control Feedback

Galeti

Higuti

Kitano

et al. 2017

IEEE J. Select. Topics Quantum Electron.

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“…(18) can be avoided by observing maximum of the spectrum magnitude for each frequency nf 0 (n 1; 2; 3; …). According to [7], when the maximum is switching between 3f 0 and 4f 0 by the random phase shift, then C is monotonic within a given limited range of 4.2 to 5.13. This is also convenient to adjust C to 4.44 from Eq.…”

Section: Research Articlementioning

confidence: 99%

Michelson interferometer vibrometer using self-correcting synthetic-heterodyne demodulation

2015

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Synthetic-heterodyne demodulation is a useful technique for dynamic displacement and velocity detection in interferometric sensors, as it can provide an output signal that is immune to interferometric drift. With the advent of cost-effective, high-speed real-time signal-processing systems and software, processing of the complex signals encountered in interferometry has become more feasible. In synthetic heterodyne, to obtain the actual dynamic displacement or vibration of the object under test requires knowledge of the interferometer visibility and also the argument of two Bessel functions. In this paper, a method is described for determining the former and setting the Bessel function argument to a set value, which ensures maximum sensitivity. Conventional synthetic-heterodyne demodulation requires the use of two in-phase local oscillators; however, the relative phase of these oscillators relative to the interferometric signal is unknown. It is shown that, by using two additional quadrature local oscillators, a demodulated signal can be obtained that is independent of this phase difference. The experimental interferometer is a Michelson configuration using a visible single-mode laser, whose current is sinusoidally modulated at a frequency of 20 kHz. The detected interferometer output is acquired using a 250 kHz analog-to-digital converter and processed in real time. The system is used to measure the displacement sensitivity frequency response and linearity of a piezoelectric mirror shifter over a range of 500 Hz to 10 kHz. The experimental results show good agreement with two data-obtained independent techniques: the signal coincidence and denominated n-commuted Pernick method.

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“…ptical measurement techniques, e.g. optical interferometry, are nowadays popular in the field of surface texture measurement due to their fast measurement speed and high measurement resolution [1]- [3]. In comparison to the raster scanning style of tactile measurements, optical methods instantly acquiring raw data for producing profile/areal surfaces are more effective to determine the geometrical nature of surfaces without halting the manufacturing process.…”

Section: Introductionmentioning

confidence: 99%

Application of Clustering Filter for Noise and Outlier Suppression in Optical Measurement of Structured Surfaces

Lou

Tang

Zeng

et al. 2020

IEEE Trans. Instrum. Meas.

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In comparison to tactile sensors, optical techniques can provide a fast, non-destructive profile/areal surface measurement solution. Nonetheless, high measurement noise, unmeasured points and outliers, are often observed in optical measurement, particularly for structured surfaces. To alleviate their detrimental impacts on the characterization of surface topography as well as the examination of micro/nanoscale geometries, a post-processing filtering technique, i.e. the clustering filter, which is essentially an iterative process to find the aggregation center of a cluster of points, is implemented. The clustering filter is particularly useful for noises and outlier suppression for optical measurement of structured surfaces due to its edge-preserving capability. Five surface samples with structured features are measured by an in-house developed dispersive interferometer and a commercial white light interferometer, thereafter the measured surface data is filtered by the clustering filter. Both noise and outliers are suppressed, which not only facilitates the visualization and characterization of surface topography, but also enables the accurate evaluation of local functional geometries.

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Nanodisplacement Measurements of Piezoelectric Flextensional Actuators Using a New Interferometry Homodyne Method

Cited by 15 publications

References 21 publications

Polarimetric Optical High-Voltage Sensor Using Synthetic-Heterodyne Demodulation and Hilbert Transform With Gain Control Feedback

Polarimetric Optical High-Voltage Sensor Using Synthetic-Heterodyne Demodulation and Hilbert Transform With Gain Control Feedback

Michelson interferometer vibrometer using self-correcting synthetic-heterodyne demodulation

Application of Clustering Filter for Noise and Outlier Suppression in Optical Measurement of Structured Surfaces

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