Handheld optical system for skin topography measurement using. The evolution of surface profilometry measurements has closely followed the. Structured light phase measuring profilometry pattern design for. The analyzers phase format displays a phaseversusfrequency or phaseversuspower measurement. Surface shape measurement by digital phaseshifting moire profilometry oncontacting electrooptical techniques. 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.
A novel encodedphase technique for phase measuring profilometry article pdf available in optics express 1915. Connection diagram to measure the three phase power with one wattmeter. Deflectometry is able to satisfy this demand because it can. New phase measuring deflectometry device for midtohigh spatial frequency surface metrology alejandro v.
Saturation model and phase recovering for phase measuring. Measuring three phase power electronic measurements. Of course, given that the internal dimensions of microfluidics cells change upon sealing, that ability to measure the. However, pixel matching by the global traversing algorithm takes up most of the time in the whole reconstruction process. 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.
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. Cathoderay oscilloscopes cros provide a simple means for measuring the phase difference between two sinusoidal signals. Osa dynamic phase measuring profilometry for rigid. The power modulation may be obtained with an electrooptic modulator, acting on a continuouswave laser beam. Online phase measuring profilometry based on phase matching is proposed. Improved algorithm for phasetoheight mapping in phase. Osa automated phasemeasuring profilometry of 3d diffuse. Together these rolls cover all needs of flatness measurement regardless of the application and metal type being rolled. In the confocal mode, the profilometer can carry out measurements with an. The phase difference between two sinusoidal waveforms that have the same frequency and are free of a dc component can be conveniently described as shown in fig. 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.
High speed 3d surface profilometry employing trapezoidal hsi. The direct mapping formula can be generated by measuring the phases of several different parallel planes rather than geometric parameters of the optical system. 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. However, applying pmp method to industrial 3d inspection is still a big challenging problem due to rigorous industrial. Fpgabased phase measuring profilometry system request pdf. Maxam foundation maxam chair blasting solutions profilometry and deviation measuring in designing blasts. 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. Group and phase delay measurements with vector network analyzer zvr using a vector network analyzer from the zvr family, not only magnitude and phase can be measured, but also group delay and even phase delay.
Nguyen graduate institute of automation technology, national taipei university of technology, taipei 106, taiwan email. Introduction the focimeter, lensmeter, or lensometer is the standard instrument used to measure the powers of spectacle lenses. Measuring phase with stokes measurements angela dudley 1, giovanni milione 2, robert alfano 2 and andrew forbes 1. The following graphic lists five reasons for measuring both magnitude and phase.
New phase measuring deflectometry device for midtohigh. 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. The profilometry of the tubing was conducted directly following the eddy current exam. College of optometry, university of houston 2010 i. Flatness measurement of screen using 3d profilometry author. Optical threedimensional sensing by phase measuring. An efficient and robust microphase measuring profilometry is proposed to reduce the effects of global illumination. Surface topography is measured and reconstructed quickly and.
The proposed unwrapping method has high confidence probability in the unwrapping. 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. This paper presents a dynamic phase measurement profilometry pmp method based on the simulated annealing algorithm. Since the sum and subtraction of readings are done to calculate total true power of a threephase system, methods shown are not used practically in industry. Based on research of the traditional phaseshifting profilometry psp method, a tilted measurement system is proposed. Gamma model and its analysis for phase measuring profilometry article pdf available in journal of the optical society of america a 273. Mar 10, 2012 an improved algorithm for phase toheight mapping in phase measuring profilometry pmp is proposed, in which the phase toheight 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. Conventional surface profilometry usually scan the sample surface from just one direction. Automated phasemeasuring profilometry of 3d diffuse objects.
Jan 25, 2014 when doing measurements on a three phase power installation, the power in all three phases must be measured simultaneous to become the total power. Measurements with 3d noncontact optical profilometry. With the proposed algorithm, both the phase measurement and system calibration can be completed simultaneously, which. Such 360 3d inspection ensures the narrowest tolerances in quality control of manufacturing processes. Measurement of the time delay between two periodic signals. This article presents a new optical measurement method employing a hsi hue. The fourier transform profilometry method is used for surface topography measurements. A resonant type of modulator can be operated with relatively low input voltage, but only with a small range of modulation frequencies, making the removal of the mentioned ambiguity. 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.
A fast and practical calibration method for the phase. However, applying pmp method to industrial 3d inspection is still a big challenging problem due to rigorous industrial measurement conditions including large surface. Lluis santalo sn, e17071 girona, spain b faculty of electrical engineering and computing, university of zagreb, unska 3, hr0 zagreb, croatia. A shearing polarization interferometer is used for projection. Flatness measurement of screen using 3d profilometry. Basic parts of a phase measuring interferometer a phase measuring interferometer consists of a light source, an illumination system providing uniform illumination across the test surface, a beamsplitter usually a cube or pellicle so both beams have the same optical path, a reference surface needs to be. Using a vector network analyzer from the zvr family, not only magnitude and phase can be measured, but also group delay and even phase delay. Having a calibrated projectorcamera pair, a light pattern is projected onto the scene and imaged by the camera. Surface shape measurement by digital phaseshifting moire.
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. 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. Analysis and identification of phase error in phase.
A phasemeasuring interferometer consists of a light source, an illumination system providing uniform illumination across the test surface, a beamsplitter usually a cube or pellicle so both beams have the same optical path, a reference surface needs to be. Profilometry and deviation measuring in designing blasts. Apparatus the apparatus consists of a penetrometer made up of a stand and a penetrating object. 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. For this there are three commonly used methods who are described in this article. In the case of phase measuring profilometry pmp, the projected patterns are composed of a rolling sinusoidal wave, but as a set of.
Whereas phase delay measurements produce the highest accuracy for the electrical length of nondispersive devices under test, such as coaxial cables, group delay measurements also give a detailed insight. Comparison of spectral reflectance and stylus profilometry. A state of the art in structured light patterns for. The phase difference between two sinusoidal waveforms that have the same frequency and are free of a dc component can be conveniently described as shown in the illustration. Sep 21, 2014 industrial metrology and inspection systems commonly rely on phase measurement profilometry pmp using sinusoidal fringe patterns projecting, yielding dense, and accurate 3d reconstruction regardless of the presence of texture. Analysis and identification of phase error in phase measuring.
Highresolution 3d profilometry with binary phaseshifting. Measurement of consistency by penetrometry this test is intended to measure, under determined and validated conditions, the penetration of an object into the product to be examined in a container with a specified shape and size. Another important advantage is that it does not have the singular point. Pdf a novel encodedphase technique for phase measuring. The most straightforward approach to use is direct measurement. A new method for both the phaseheight mapping and the 3d coordinate calibration in phasemeasuring profilometry pmp is presented. In dynamic pmp for rigid objects, pixel matching is an effective method to make onetoone pixel correspondence in each captured pattern. Request pdf on may 14, 2019, albrecht hess and others published fpgabased phase measuring profilometry system find, read and cite all the research you need on researchgate. Industrial metrology and inspection systems commonly rely on phase measurement profilometry pmp using sinusoidal fringe patterns projecting, yielding dense, and accurate 3d reconstruction regardless of the presence of texture. The instrument is now able to measure each of the transparent surfaces by selecting it and differentiating it from the others seefigure 5. High speed 3d surface profilometry employing trapezoidal.
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. The proposed technology makes three constraints of the traditional phaseshifting profilometry measurement system less constrains. Modulation frequencies of many megahertz or even multiple gigahertz are easily obtained. This setup is used to measure the profile of a thin film sample and compared with a commercial noncontact optical profilometer. 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 relative phase between two waveforms using an. Phase measuring profilometry is a method of structured light illumination whose threedimensional reconstructions are susceptible to error from nonunitary gamma in. The variance of the estimated phase is constant for any phase. Method oscilloscope requirements waveform requirements.
The profilometry of three dimensional objectives based on phase approaching of projected grating is widely used in various fields of application engineering. Stylus profilometry is an easytounderstand mechanical technique for measuring film thickness. Enhanced phase measurement profilometry for industrial 3d. Study of the phase recovering algorithm for saturated fringe patterns in the projection grating phase shifting profilometry. Factor of safety n suitable values depend on inherent danger, certainty of calculations, certainty of material properties, etc. Since the sum and subtraction of readings are done to calculate total true power of a three phase system, methods shown are not used practically in industry. The phase information of the object in those captured. This document covers four methods and summarizes the advantages and limitations of each. Measuring methods, instruments, and metrology dawn a. Figure 1 methods of measuring the power in three phase systems. Deformed grating images are detected by an array camera and processed by a microcomputer. Weiss, david ginger, keith jackson, don eigler, harold craighead, eric isaacs 15 2. Group and phase delay measurements with vector network. Jun 17, 2017 profilometry countable and uncountable, plural profilometries the use of a technique in the measurement and profiling of an object.
While the work previously reported is only valid for. Twocamera phase measuring profilometry system scientific. The code is in matlab and the fourier transform profilometry technique is adopted from. By measuring this phase accurately using phase modulation methods and by determining points on the reference plane and the. Phaseangle measurement accessscience from mcgrawhill.
A calibration gauge containing four virtual calibration planes is designed. High speed 3d shape measurement with temporal fourier. A state of the art in structured light patterns for surface. Study on phaseshifting profilometry of tilted measurement. Phase measuring profilometry pmp, a wellknown optical metrology based on active stereovision, has been developed to meet the demands of various applications. Contemporary advances in qualitative and quantitative analysis of dental hard tissues using noncontact threedimensional optical profilometry editorial j community med health educ 6. Improving the accuracy performance of phase shifting profilometry for the measurement of objects in motion abstract this letter presents a new approach to reducing the errors associated with the shape measurement of a rigid object in motion by means of phase shifting profilometry. Improving the accuracy performance of phaseshifting. The exit pupil of the projecting system and the entrance pupil of the ccd imaging system are not horizontal and not.
Figure 1 methods of measuring the power in threephase systems. Phase shift method for distance measurements rp photonics. Online phase measuring profilometry based on phase matching. The methodology of performing eddy current profiling of tubing. However, challenges remain to perform highquality 3d shape measurement with offtheshelf digital video projectors. 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. In previous chapter the microcontroller generated the signal ref and. It can be seen that the phase angle can be considered as a measure of the time delay between two periodic signals expressed as a fraction of the.
Presented at 59 th annual saip conference university of. The primary advantage of stylus profilometry is that it can be used on all solid films, including opaque materials such as thick metal films. A state of the art in structured light patterns for surface pro. Pdf gamma model and its analysis for phase measuring. By measuring this phase accurately using phase modulation methods and by determining points on the reference plane and the object having identical. 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 consuming depending on the desired spatial resolution. The application of the calibration gauge avoids the translation of the standard plane during the calibration process. Introductionstress in machine components should be accurately computed. A precise 360 surface inspection of parts with a cylindrical shape is in need to measure detailed surface feature from different angles.
Comparison of linear and nonlinear calibration methods for phase measuring profilometry article pdf available in optical engineering 464 april 2007 with 420 reads how we measure reads. Introduction to lensometry college of optometry, university. Measuring the complex impedance of an antenna is a good example. Optical threedimensional sensing by phase measuring profilometry. A direct mapping algorithm for phasemeasuring profilometry. Quick precorrection of a grating fringe for phase measuring profilometry. When used in communications systems to pass signals, components or circuits must not cause excessive signal distortion. The stressometer measuring roll family the stressometer family of solid flatness measuring rolls for cold rolling mills has three members. The technique in which a diamond stylus, in contact with a sample, measures surface variations as a function of position. A new method for both the phase height mapping and the 3d coordinate calibration in phase measuring profilometry pmp is presented.
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