Search

When using the grating projection three-dimensional measurement method to measure the surface of an object with high reflectivity, the high reflectivity of the object surface causes some pixels of the image to be saturated, which makes the phase calculation inaccurate. In order to solve this problem, a dynamic phase resolution algorithm was proposed to make the over-exposed phase-shift diagram not participate in the phase calculation by introducing an over-exposure factor, and the non-fixed-step phase shift and auxiliary fringes were used to perform the phase calculation. The results show that the algorithm effectively reduces the noise in the highly reflective area, improves the quality of point cloud reconstruction, and shortens the point cloud processing line by completing the reconstruction of high surface point clouds with only one set of deconvolution atlases. It can be seen that the method based on dynamic deconvolution effectively improves the point cloud processing efficiency while ensuring the effect of high surface point cloud reconstruction. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

PZT micro-displacement actuator is the key component in phase shift interference technique. For the requirements of micro-displacement in phase shifting interferometry system, a new type of PZT micro-displacement actuator and Power supply were develoved. The Power supply, composed of DC amplification structure by using integrated power overational amplifie and a small number of peripheral devices, can effectively solve the nonlinear problems of output voltage, reduce the phenomenon of self-excited, and improve system stability. By experimental calibration testing, the unique features of the power supply are low ripple, strongly driving capability and fine stabling. The experiment results have shown the effectiveness and advantages of the PZT micro-displacement actuator. [ABSTRACT FROM AUTHOR]

Because of its high sensitivity to vibrations, the phase-shifting interferometry system is often quite complicated. A time-frequency domain (TFD) method is proposed in this research, which could make the system in compact for field testing. A large number of interferograms are captured. For the particular pixels in interferograms, a series of distorted phase is obtained through wide bandwidth filtering and reverse Fourier transform of the spectrum of intensity series. Then the linear fit method is used. For a large enough number of interferograms, a linear fit of the distorted phase efficiently could reduce random noises towards zero, and astringe other nonrandom disturbances into a nonzero data which is independent to index of pixels and therefore dose not influence the shape of the whole wave front. Under a precise of A/100, the maximum amplitude-frequency product (AFP) of anti-vibration capability was obtained by simulation, which verifies the feasibility of the method and lays the foundation for application of the method in compact system. [ABSTRACT FROM AUTHOR]

The main factors that affect the phase measurement accuracy were analyzed and simulated in detail for the case of detecting high-density fringes by CCD in phase-shifting interferometry. The influences of the pixel size of CCD, random noise and sampling quantized lever of the intensity in interferogram were discussed. The results indicate that, with the increase of CCD pixel size and random noise's RMS, the signal to noise ratio of sequence intensity detected by CCD would be worse, and the phase measurement error is getting greater. When the signal to noise ratio is greater than about 24, the phase measurement accuracy could be better than π/50rad, which is equivalent to the λ/100 better of optical path difference. This research provides a theoretical quantitative basis for the further study of extending the measuring range of phase-shifting interferometry. [ABSTRACT FROM AUTHOR]