High-speed measurement of three-dimensional surface profiles up to 10 μm using two-wavelength phase-shifting interferometry utilizing an injection locking technique

The development of a three-dimensional surface profilometer using digital fringe projection technology and phase-shifting principle is presented. Accurate and high-speed three-dimensional profile measurement plays a key role in determining the success of process automation and productivity. By integrating a digital micromirror device (DMD) with the developed system, exclusive advantages in projecting flexible and accurate structured-light patterns onto the object surface to be measured can be obtained. Furthermore, the developed system consists of a specially designed micro-projecting optical unit for generating flexibly optimal structured-light to accommodate requirements in terms of measurement range and resolution. Its wide angle image detection design also improves measurement resolution for detecting deformed fringe patterns. This resolves the problem in capturing effective deformed fringe patterns for phase shifting, especially when a coaxial optical layout of a stereomicroscope is employed. Experimental results verified that the maximum error was within a reasonable range of the measured depth. The developed system and the method can provide a useful and effective tool for 3D full field surface measurement ranging from µm up to cm scale.

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A Study on Autonomic High Speed Measurement of a Three Dimensional Shape by Using a Non-contact Sensor for Detecting an Inclination Angle and a Gap Distance (2nd Report)

Journal of the Japan Society for Precision Engineering ◽

10.2493/jjspe.60.954 ◽

1994 ◽

Vol 60 (7) ◽

pp. 954-958

Author(s):

Hideki AOYAMA ◽

Kazuo YAMAZAKI ◽

Kee Sein LEE ◽

Kunitoshi NISHIMURA

Keyword(s):

Inclination Angle ◽

High Speed ◽

Three Dimensional ◽

Speed Measurement ◽

Contact Sensor ◽

Dimensional Shape ◽

Three Dimensional Shape

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Experimental visualization of aerodynamic sound sources using parallel phase-shifting interferometry

Experiments in Fluids ◽

10.1007/s00348-020-03038-x ◽

2020 ◽

Vol 61 (9) ◽

Author(s):

Risako Tanigawa ◽

Kohei Yatabe ◽

Yasuhiro Oikawa

Keyword(s):

Optical Method ◽

High Speed ◽

Near Field ◽

Phase Shifting ◽

Flat Plates ◽

Noise Sources ◽

Sound Sources ◽

Aerodynamic Sound ◽

Phase Shifting Interferometry ◽

Pressure Fields

Abstract Aerodynamic sound is one of the causes of noise in high-speed trains, automobiles, and wind turbines. To investigate the characteristics of aerodynamic sound generation, measurements around the sound sources are required. Aerodynamic sound is typically measured using microphones. However, microphones cannot capture the near-field of aerodynamic sound because they become new noise sources inside the air flow. To observe the aerodynamic sound near-field, we performed two-dimensional visualization of aerodynamic sound using an optical method. The optical method used in this research, parallel phase-shifting interferometry (PPSI), can detect the pressure within the measurement area as variations of the phase of light. PPSI can therefore visualize the pressure fields. We visualized both the sound pressure and flow components of the sound generated by flow around a square cylinder and flat plates. The visualized pressure fields are provided as animations in the online resources. Analysis of the sound and flow component time variations confirmed the correlations between them. Graphic abstract

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