Laser integrated measurement of surface roughness and micro-displacement

Abstract

An optical method based on laser scattering and optical triangulation for measurement of surface roughness and micro-displacement measurement is proposed. The technique allows evaluation of surface roughness and micro-displacement of a specimen using just one device. The principle of the method and the basic instrumentation design are described and the validity of the principle is demonstrated by experimental evaluations. Results show that, for specimens with surface roughnesses (R a ) in the range 0.005-0.1 µm, displacements in the range ±300 µm can be readily measured.

Laser methods based on an analysis of scattered light for automated, in-process inspection of machined surfaces: A review

“…The measuring signal obtained simultaneously from two cameras, in the form of image data, was processed in Matlab environmental. As a result of the research undertaken it was possible to get a range of surface roughness very similar to the one described in the work [20]. The results of the subsequent work carried out using the system are presented by G. Y. Tian, R. S. Lu and D. Gledhill [29], while the experimental setups, based on similar methods are discussed in [30,31].…”

“…Only a few of them are manufactured commercially. The relatively narrow use of these systems is also as a result of the lack of appropriate methods meeting the requirements of such measurements, as well as the lack of unified standards that define the criteria by which such systems are used for the carrying out of measurements Among the experimental systems used for research, an interesting system was developed by researchers at the Sichuan University (China) and the National University of Singapore A c c e p t e d M a n u s c r i p t [20,21]. An integrated probe is designed for the assessment of the surface roughness using one of the light scattering methods -ARS, and micro-displacements using laser triangulation.…”

Implementation and Optimization of a Dual-confocal Autofocusing System

“…Autofocusing systems have been widely applied in recent decades in a variety of industrial manufacturing and measurement fields, such as in cellphone camera modules, automatically available optical inspection, and dynamic tracking systems [4]. In brief, many autofocusing systems have been developed, and these autofocusing systems can be broadly classified as image-based methods [5][6][7][8][9][10][11][12][13][14][15][16] and optics-based methods [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Both need to be driven by moving motors to achieve the function of autofocusing, which limits the possibility of their direct implementation for in-line inspection.…”

A Compact High-Speed Image-Based Method for Measuring the Longitudinal Motion of Living Tissues

“…Thus, to realize an AMC system for eliminating the effect of tissue movement, a high-speed displacement sensor for measuring the motion of living tissues in real time is indispensable. Currently, state-of-the-art methods for measuring the motion of living tissues are based on an optical system, such as optical triangulation [15][16][17][18][19][20], high speed optical imaging [12,21], optical coherence tomography (OCT) [22,23] and image correlation computation [14,24]. Optical systems can be further broadly classified as nonimage-based and image-based systems.…”