Three-dimensional profile measurement based on modified temporal phase unwrapping algorithm

The profilometry of three dimensional objectives based on phase approaching of projected grating is widely used in various fields of application engineering. In this paper, two cameras are equipped in our system to obtain fast and static measurement compared to the conventional measuring system with single camera which needs rotated measurement. Algorithm of phase unwrapping based on reliability is also adopted to improve the performance which avoid the breakage of projected grating. Experimental data indicates the measurement error of this Two-camera phase measuring profilimetry system is within 1%. This new profilometry system has great potential application value in the profile measurement of static three dimensional targets.

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Three-dimensional digital imaging based on temporal phase unwrapping with parallel DSP

10.1117/12.783362 ◽

2007 ◽

Author(s):

Xiaodong Wang ◽

Peng Xiang ◽

Jindong Tian

Keyword(s):

Digital Imaging ◽

Three Dimensional ◽

Phase Unwrapping ◽

Temporal Phase

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Profilometry of three-dimensional discontinuous solids by combining two-steps temporal phase unwrapping, co-phased profilometry and phase-shifting interferometry

Optics and Lasers in Engineering ◽

10.1016/j.optlaseng.2015.12.017 ◽

2016 ◽

Vol 87 ◽

pp. 75-82 ◽

Cited By ~ 12

Author(s):

Manuel Servin ◽

Moises Padilla ◽

Guillermo Garnica ◽

Adonai Gonzalez

Keyword(s):

Three Dimensional ◽

Phase Unwrapping ◽

Phase Shifting ◽

Phase Shifting Interferometry ◽

Temporal Phase

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Harmonic Analysis on Low Quality Tidal Data

Volume 8B: Ocean Engineering ◽

10.1115/omae2014-24014 ◽

2014 ◽

Author(s):

Joost den Haan

Keyword(s):

Harmonic Analysis ◽

Three Dimensional ◽

Measurement Data ◽

Tidal Energy ◽

Energy Yield ◽

Profile Measurement ◽

Current Profile ◽

Tidal Power ◽

Data Set ◽

Tidal Forcing

The aim of the study is to devise a method to conservatively predict a tidal power generation based on relatively short current profile measurement data sets. Harmonic analysis on a low quality tidal current profile measurement data set only allowed for the reliable estimation of a limited number of constituents leading to a poor prediction of tidal energy yield. Two novel, but very different approaches were taken: firstly a quasi response function is formulated which combines the currents profiles into a single current. Secondly, a three dimensional vectorial tidal forcing model was developed aiming to support the harmonic analysis with upfront knowledge of the actual constituents. The response based approach allowed for a reasonable prediction. The vectorial tidal forcing model proved to be a viable start for a full featuring numerical model; even in its initial simplified form it could provide more insight than the conventional tidal potential models.

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An Acoustic System for Pipeline Profile Measurement

Journal of Energy Resources Technology ◽

10.1115/1.3230956 ◽

1983 ◽

Vol 105 (4) ◽

pp. 475-479

Author(s):

H. Van Calcar

Keyword(s):

Measurement Technique ◽

Measurement System ◽

Performance Enhancement ◽

Three Dimensional ◽

Profile Measurement ◽

Baseline Measurement ◽

Acoustic System ◽

Position Measurement ◽

Long Baseline ◽

Hardware Configuration

This paper presents an acoustic position measurement system used for precise three-dimensional flowline profile measurement. The system measures several points along the flowline using the long-baseline measurement technique and augments this measurement with depth telemetry repeaters to maintain elevation accuracy throughout the changing installation geometry. The paper discusses both the measurement system and the performance enhancement features. The paper concludes with a discussion of the hardware configuration and the accuracy that can be expected when the technique is extended into deeper operating areas.

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An Error-Reduction Method for Temporal Phase Unwrapping Based on Double Three-Step Phase-Shifting and Least-Squares Fitting

Advanced Engineering Forum ◽

10.4028/www.scientific.net/aef.6-7.76 ◽

2012 ◽

Vol 6-7 ◽

pp. 76-81

Author(s):

Yong Liu ◽

Ding Fa Huang ◽

Yong Jiang

Keyword(s):

Least Squares ◽

Reduction Method ◽

Intermediate Phase ◽

Error Reduction ◽

Phase Unwrapping ◽

Phase Shifting ◽

Surface Measurement ◽

Acquisition Time ◽

Least Squares Fitting ◽

Temporal Phase

Phase-shifting interferometry on structured light projection is widely used in 3-D surface measurement. An investigation shows that least-squares fitting can significantly decrease random error by incorporating data from the intermediate phase values, but it cannot completely eliminate nonlinear error. This paper proposes an error-reduction method based on double three-step phase-shifting algorithm and least-squares fitting, and applies it on the temporal phase unwrapping algorithm using three-frequency heterodyne principle. Theoretical analyses and experiment results show that this method can greatly save data acquisition time and improve the precision.

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