Mesoscale Profile Measurement Improved by Intelligent Measurement Technology

The phase-to-height imaging model, as a three-dimensional (3D) measurement technology, has been commonly applied in fringe projection to assist surface profile measurement, where the efficient and accurate calculation of phase plays a critical role in precise imaging. To deal with multiple extra coded patterns and 2π jump error caused to the existing absolute phase demodulation methods, a novel method of phase demodulation is proposed based on dual variable-frequency (VF) coded patterns. In this paper, the frequency of coded fringe is defined as the number of coded fringes within a single sinusoidal fringe period. First, the effective wrapped phase (EWP) as calculated using the four-step phase shifting method was split into the wrapped phase region with complete period and the wrapped phase region without complete period. Second, the fringe orders in wrapped phase region with complete period were decoded according to the frequency of the VF coded fringes and the continuous characteristic of the fringe order. Notably, the sampling frequency of fast Fourier transform (FFT) was determined by the length of the decoding interval and can be adjusted automatically with the variation in height of the object. Third, the fringe orders in wrapped phase region without complete period were decoded depending on the consistency of fringe orders in the connected region of wrapped phase. Last, phase demodulation was performed. The experimental results were obtained to confirm the effectiveness of the proposed method in the phase demodulation of both discontinuous objects and highly abrupt objects.

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Special Issue on Intelligent Measurement for Advanced Production Engineering

International Journal of Automation Technology ◽

10.20965/ijat.2017.p0681 ◽

2017 ◽

Vol 11 (5) ◽

pp. 681-681

Author(s):

Satoru Takahashi ◽

Yuki Shimizu ◽

Yasuhiro Mizutani

Keyword(s):

Industrial Revolution ◽

Value Added ◽

Leading Edge ◽

Sensor Technology ◽

Measurement Technology ◽

Surface Metrology ◽

Special Issue ◽

Production Engineering ◽

Intelligent Measurement ◽

Measurement Surface

Measurement technology in the field of production engineering has long played an essential role in improving the yield and reliability of manufactured products, and it will continue to increase in importance to the manufacture of advanced products. The development of intelligent and innovative measurement technologies will not only be essential but also indispensable to the creation of high value-added products as next-generation advanced products, manufactured based on leading-edge production technologies and science. The importance of measurement technologies indispensable to the digitization of things has been increasing particularly dramatically in the industrial revolution of production based on the innovative advancement of big data management and the cloud computing environment. This special issue addresses the latest research advances into measurement for production engineering. This covers a wide area, including dimensional measurement, surface metrology, uncertainty, traceability, calibration, in-process and on-line metrology, machine tool metrology, optical metrology, micro and nano metrology, and applied sensor technology. We hope that learning more about these advances will enable the readers to share in the authors’ experiences and knowledge of technologies and development. All papers were refereed through careful peer reviews. We would like to express our sincere appreciation to the authors for their submissions and to the reviewers for their invaluable efforts, ensuring the success of this special issue.

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