Uniaxial 3D Measurement with Auto-Synchronous Phase-Shifting and Defocusing Based on a Tilted Grating

Conventional uniaxial techniques generally require shifting objects or projection grating with the assistance of a high-precision mechanical moving component. To overcome this limitation, we propose a novel uniaxial 3-D shape measurement system with auto-synchronous phase-shifting and defocusing by using a tilted and fixed projection grating. The tilted focused image plane (FIP), which is reflected by a mirror at about 90 degrees, could be shifted across the measured surface by slightly rotating the mirror within a small angle range. This procedure will simultaneously introduce the change in defocusing and phase-shifting of the fringe. The modulation curve of each point can be deciphered by Fourier fringe analysis after a sequence of fringe intensities is acquired. Since both the measured object and projection grating are fixed, the proposed method could make the measurement system more compact and flexible. Both computer simulation and experiments are carried out to demonstrate the validity of this proposed system.

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Fast 3D measurement system using generalized phase-shifting method for deformation measurement of human hand

Optical Technology and Measurement for Industrial Applications 2020 ◽

10.1117/12.2574771 ◽

2020 ◽

Author(s):

Shusuke Kobayashi ◽

Nobukazu Yoshikawa

Keyword(s):

Measurement System ◽

Deformation Measurement ◽

Phase Shifting ◽

Human Hand ◽

3D Measurement ◽

Phase Shifting Method ◽

3D Measurement System

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3D shape measurement system based on fringe projection in 4-step phase shifting

Journal of Applied Optics ◽

10.5768/jao201536.0403005 ◽

2015 ◽

Vol 36 (4) ◽

pp. 584-589 ◽

Cited By ~ 1

Author(s):

Shang Zhong-yi ◽

Li Wei-xian ◽

Dong Ming-li ◽

Duan Liang-jun

Keyword(s):

Measurement System ◽

Phase Shifting ◽

Fringe Projection ◽

Shape Measurement ◽

3D Shape ◽

3D Shape Measurement

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Algorithm Design of 3D Measurement System Based on FPGA

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.687-691.961 ◽

2014 ◽

Vol 687-691 ◽

pp. 961-965 ◽

Cited By ~ 1

Author(s):

Wei Feng Zhong ◽

Zhao Hang ◽

Yu Heng Yin ◽

Jian Wei Ma

Keyword(s):

Measurement System ◽

High Efficiency ◽

Algorithm Design ◽

Shape Measurement ◽

Cordic Algorithm ◽

3D Measurement ◽

3D Shape ◽

3D Shape Measurement ◽

Phase Calculation ◽

3D Measurement System

Aiming at improving the 3D shape measurement speed and accuracy, the design of floating point algorithm for 3-D shape measurement using FPGA, is proposed. By using four-step phase shifting method for measuring 3D measurement system, using CORDIC algorithm to achieve phase calculation of the phase shift method, the algorithm is realized by Verilog language in FPGA, and to make simulation and verification in Modelsim. The study of 3D shape measurement system have a breakthrough from the design performance and hardware.Finally, the MATLAB simulation proved its effectiveness and viability.The experimental results show that the advantages of high data processing speed, high efficiency and high precision,etc.

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High-speed three-dimensional shape measurement system using a modified two-plus-one phase-shifting algorithm

Optical Engineering ◽

10.1117/1.2802546 ◽

2007 ◽

Vol 46 (11) ◽

pp. 113603 ◽

Cited By ~ 66

Author(s):

Song Zhang

Keyword(s):

Measurement System ◽

High Speed ◽

Three Dimensional ◽

Phase Shifting ◽

Shape Measurement ◽

Dimensional Shape ◽

Three Dimensional Shape

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Two-step Gradient-assisted Phase-shifting Demodulation Algorithm for Fast 3D Reconstruction

Measurement Science and Technology ◽

10.1088/1361-6501/ac3677 ◽

2021 ◽

Author(s):

Yanxue Wu ◽

Gaoxu Wu ◽

Shichao Yang ◽

Tian Yang ◽

Fei Liu

Keyword(s):

3D Reconstruction ◽

High Precision ◽

Phase Shifting ◽

3D Measurement ◽

Noise Tolerance ◽

Intensity Gradient ◽

Step Method ◽

Heterodyne Method ◽

Absolute Phase ◽

Conventional Methods

Abstract The conventional multi-frequency heterodyne method is one of the most widely used methods in non-contact 3D measurement. However, it needs to project different phase-shifting patterns with different frequencies, so a large number of patterns are required. For most conventional methods, the fringe period number of the projected patterns is usually small due to its limited noise tolerance, though the larger fringe period number always means higher accuracy. We propose a two-step phase-shifting demodulation algorithm based on intensity-gradient. In this method, only two patterns for each frequency are required. With the intensity-gradient of the two patterns, we obtain the wrapped phase of each frequency. Next, the absolute phase is retrieved from the three wrapped phases with the heterodyne algorithm. Because only two patterns are required for each frequency, the proposed method is more robust and has higher measuring speed compared with the traditional 3-frequency 4-step heterodyne method. Simulations and experiments prove the feasibility and effectiveness of the method, and demonstrate that the proposed method extends the noise tolerance and achieves high-precision with only a half of the patterns required by the traditional 3-frequency 4-step method.

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Real-Time Shape Measurement by Unwrapping Method Using Aliasing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.326-328.31 ◽

2006 ◽

Vol 326-328 ◽

pp. 31-34 ◽

Cited By ~ 2

Author(s):

Motoharu Fujigaki ◽

Toshio Toyotake ◽

Toru Matui ◽

Yoshiharu Morimoto

Keyword(s):

Real Time ◽

Measurement System ◽

Measurement Method ◽

Fourier Spectrum ◽

Phase Unwrapping ◽

Phase Shifting ◽

Cycle Phase ◽

Shape Measurement ◽

Time Shape ◽

Two Component

We previously proposed a real-time shape measurement method using two-component synthesis grating projection. In the method, phase unwrapping of the projected grating is performed by using aliasing of the Fourier spectrum of the grating images. It requires only 5 images obtained for one-cycle phase-shifting. Each phase in the two-component can be extracted from only 5 phase-shifted grating images. In this paper, we propose a real-time shape measurement system. The theory, the algorithm for the analysis and the experimental results are shown.

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