A new method for both the phaseheight mapping and the 3d coordinate calibration in phasemeasuring profilometry pmp is presented. Traveling from a to b represents one cycle of the wave, b to e another cycle. A direct mapping algorithm for phasemeasuring profilometry. Measuring relative phase between two waveforms using an.
Nguyen graduate institute of automation technology, national taipei university of technology, taipei 106, taiwan email. Stylus profilometry is an easytounderstand mechanical technique for measuring film thickness. In this paper, two cameras are equipped in our system to obtain fast and static measurement compared to the conventional measuring system with single camera which needs rotated measurement. In general, multiframe fringe patterns can get more accurate and reliable results, but it is significant to use. Microlens characterization using contact profilometry and pointspread function measurement craig r. When a sinusoidal grating is projected on either a reference plane or a diffuse object to be measured, every point along a line normal to the grating lines, on the reference plane as well as the object, can be characterized by a unique phase value. Structured light illumination is an active 3d scanning technique based on projectingcapturing a set of striped patterns and measuring the warping of the patterns as they reflect off a target objects surface. Pdf robust measurement of the diffuse surface by phase. Phase measurement when one is interested in the phase relation between two signals ref and x, and these signals are not generated by the measurement system, one can use a derivative of the lockin detection technique already described in chapter 23. A profilometer is a measuring instrument used to measure a surfaces profile, in order to quantify its roughness. Calibration is to transform the 2d phase information to the world coordinates in a fringe projection 3d measurement system. A state of the art in structured light patterns for surface pro.
Optical threedimensional sensing by phase measuring. While just one fixed sinusoidal fringe is projected on a measured object moving with the pipeline, deformed patterns modulated by the object moving at the same distance moment are captured synchronously by the ccd camera. Measuring the complex impedance of an antenna is a good example. Maxam foundation maxam chair blasting solutions profilometry and deviation measuring in designing blasts.
We can generate informative and visually pleasing graphs, 2d and 3d images for you. Phase measuring profilometry and moire methodology have been widely applied to the threedimensional shape measurement of target objects, because of their high measuring speed and accuracy. Profilometry and profilometers compared to spectral. In the case of phase measuring profilometry pmp, the projected patterns are composed of a rolling sinusoidal wave, but as a set of timemultiplexed.
Surface shape measurement by digital phaseshifting moire. Cathoderay oscilloscopes cros provide a simple means for measuring the phase difference between two sinusoidal signals. Do you need powerful visual presentations of your test results for a publication, a poster, a conference, your peers or upper management. A fast and practical calibration method for the phase. It works by monitoring the height of a stylus as it drags across a step in the film see figure to right. High speed 3d surface profilometry employing trapezoidal. Phasemeasuring profilometry using sinusoidal grating springerlink. The most straightforward approach to use is direct measurement.
Conventional surface profilometry usually scan the sample surface from just one direction. When a sinusoidal amplitude grating is projected on an object, the surfaceheight distribution of the object is translated to a phase distribution of the deformed grating image. We can process, analyze and manipulate them for you. In previous chapter the microcontroller generated the signal ref and. The use of a technique in the measurement and profiling of an object. The methodology of performing eddy current profiling of tubing. Structured light threedimensional measurement based on. In the case of phase measuring profilometry pmp, the projected patterns are composed of a rolling sinusoidal wave, but as a set of. Automated phasemeasuring profilometry of 3d diffuse objects. Highresolution 3d profilometry with binary phaseshifting. Measuring relative phase between two waveforms using an oscilloscope overview there are a number of ways to measure the phase difference between two voltage waveforms using an oscilloscope. Saturation model and phase recovering for phase measuring. Improved algorithm for phasetoheight mapping in phase. Critical dimensions as step, curvature, flatness are computed from the surface topography.
Absolute phasemeasurement technique based on number theory in multifrequency grating projection profilometry. The primary advantage of stylus profilometry is that it can be used on all solid films, including opaque materials such as thick metal films. However, pixel matching by the global traversing algorithm takes up most of the time in the whole reconstruction process. Introduction the focimeter, lensmeter, or lensometer is the standard instrument used to measure the powers of spectacle lenses. Gamma calibration and phase error compensation for phase. In phasemeasuring profilometry, a sequence of phaseshifted sinewave patterns is projected onto a. Absolute phasemeasurement technique based on number. This paper presents a dynamic phase measurement profilometry pmp method based on the simulated annealing algorithm. Comparison of linear and nonlinear calibration methods for phasemeasuring profilometry article pdf available in optical engineering 464 april 2007 with 420 reads how we measure reads. The profilometry of three dimensional objectives based on phase approaching of projected grating is widely used in various fields of application engineering. The analyzers phase format displays a phaseversusfrequency or phaseversuspower measurement.
The higher educational key laboratory for measuring and control technology and instrumentations of heilongjiang province, harbin university of science and technology, harbin, china corresponding author. Fpgabased phase measuring profilometry system request pdf. Improving the accuracy performance of phaseshifting. This document covers four methods and summarizes the advantages and limitations of each. A shearing polarization interferometer is used for projection. Structured light phase measuring profilometry pattern design for. Optimized twofrequency phasemeasuring profilometry light. For the phasetoheight conversion, an equiphase coordinate method based on tworeferenceplane is proposed in this paper. New phase measuring deflectometry device for midtohigh spatial frequency surface metrology alejandro v. High speed 3d surface profilometry employing trapezoidal hsi phase shifting method with multiband calibration for colour surface reconstruction l c chen, x l nguyen and y s shu national taipei university of technology, taipei, taiwan email.
Phaseshifting profilometry for the robust 3d shape. To the left, is a standing wave with positions af noted. A calibration gauge containing four virtual calibration planes is designed. The surface height is calculated by a linear interpolation using the coordinates where have the identical phase value. Gamma model and its analysis for phase measuring profilometry. A new pixel matching method based on phase measuring profilometry pmp using the modulation of shadow areas in online 3d measurement is proposed and verified by experiments. With this instrument it is possible to measure the sphere power, cylinder power, and cylinder axis of a lens, the add powers of a multifocal lens, and, given the. A largedepthoffield projected fringe profilometry using. Pdf gamma model and its analysis for phase measuring. Profilometry and deviation measuring in designing blasts. Phase shifting profilometry for the robust 3d shape measurement of moving objects article in optics express 2716.
Gamma model and its analysis for phase measuring profilometry article pdf available in journal of the optical society of america a 273. Full refereed journal article pdf postscript references in the article citations to the article 355 citation history refereed citations to the article reads history translate this page. Shadow removal method for phaseshifting profilometry. When a sinusoidal amplitude grating is projected on an object, the surfaceheight distribution of the object is translated to a phase distribution of the deformed. In dynamic pmp for rigid objects, pixel matching is an effective method to make onetoone pixel correspondence in each captured pattern. A, b, and e are said to be in phase as they have the same displacement from baseline and are traveling in the same direction up from a. Therefore in order to obtain a large l f at a conventional imaging system, a large u should be achieved firstly. Profilometry tools and test plates can be used, but they only provide line scans or qualitative information, so a quantitative full surface measurement can be time. Analysis and identification of phase error in phase. Osa dynamic phase measuring profilometry for rigid. Phase measuring profilometry is a method of structured light illumination whose threedimensional reconstructions are susceptible to error from nonunitary gamma in. The phase information of the object in those captured. The application of the calibration gauge avoids the translation of the standard plane during the calibration process.
College of optometry, university of houston 2010 i. This article presents a new optical measurement method employing a hsi hue. Absolute phase retrieval methods for digital fringe projection. Calibration of a fringe projection 3d measurement system. The standard for profilometry x y scan area height range desktop dimensions scan speed 200 x 150mm motorized 2. By measuring this phase accurately using phase modulation methods and by determining points on the reference plane and the. New phase measuring deflectometry device for midtohigh. Lluis santalo sn, e17071 girona, spain b faculty of electrical engineering and computing, university of zagreb, unska 3, hr0 zagreb, croatia. The technique in which a diamond stylus, in contact with a sample, measures surface variations as a function of position. Phasemeasuring profilometry using sinusoidal grating. Hunter department of mechanical engineering massachusetts institute of technology cambridge, ma, usa abstract as microlens fabrication technologies proliferate, accurate and accessible metrology techniques. A random phase shift atgorithm based on the principle of phase measuring profilometry with a projected sinusoidal grating to 360 measurement of the surface topography of 3d diffuse objects is. For a noisefree system, a twowavelength phase shifting algorithm theoretically works well, yet a practical mea surement system.
Phase measuring profilometry pmp, a wellknown optical metrology based on active stereovision, has been developed to meet the demands of various applications. Highspeed 3d shape measurement using fourier transform. The code is in matlab and the fourier transform profilometry technique is adopted from. Improving the accuracy performance of phase shifting profilometry for the measurement of objects in motion lei lu,1 jiangtao xi,1, yanguang yu,1 and qinghua guo1 1school of electrical computer and telecommunications engineering, university of wollongong, wollongong, nsw, 2522, australia corresponding author. An improved algorithm for phasetoheight mapping in phasemeasuring profilometry pmp is proposed, in which the phasetoheight mapping relationship is no longer restricted to the condition that the optical axes of the imaging system must be orthogonal to the reference plane in the basic pmp.
Pdf comparison of linear and nonlinear calibration. A direct phasetoheight mapping algorithm for phasemeasuring profilometry is presented and verified by experiments. A state of the art in structured light patterns for. The profilometry of the tubing was conducted directly following the eddy current exam. Most blast benches are irregular due to the complex combination of the inherent structure of the rock mass, its geomechanical condition, and possibly damage caused in the free face by the previous blast. However, challenges remain to perform highquality 3d shape measurement with offtheshelf digital video projectors. Pdf phase measuring profilometry is a method of structured light illumination whose threedimensional reconstructions are susceptible to error from. The high resolution surface profile of a 3d diffuse object is obtained by measurement of the phase distribution across the image of a projected sinusoidal grating deformed by the surface. Online phase measuring profilometry based on phase. Online phase measuring profilometry based on phase matching is proposed. Pmp employs a timevarying phase shift to encode the position information.
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