Automatic dimensional inspection of 3D articles with high resolution and productivity is an urgent problem for industry.
It takes solving some measurement basic and applied tasks. Using the optical inspection methods, it is essential to take
into account the influence of 3D bodies' extension on their Fraunhofer diffraction pattern and images. This influence
strongly depends on the configuration of illumination, which therefore is fundamentally important. The solution for
diffraction phenomena by volumetric slit under inclined plane and spherical wave illumination has been represented. The
obtained results can be applied for investigation of formation and high-frequency filtering images of 3D bodies of
constant thickness. Ensuring the safety and high operation reliability of nuclear reactors takes 100% inspection of
geometrical parameters of fuel assemblies, which include the spacer grids performed as cellular structure with fuel
elements. The required spacer grids geometry of assembly in the transverse and longitudinal cross sections is extremely
important for maintaining the necessary heat regime. A universal method for 3D spacer grid inspection using the
diffractive optical element, which generates as the structural illumination, a multiple-ring pattern on the inner surface of
a spacer grid cell is investigated. Using some diffractive optical elements one can inspect the nomenclature of all
produced grids. Experimental results for semi-industrial version of spacer grid inspection system are presented. A
structured light method and testing results of pilot system for noncontact inspection of wire wear and its defects for train
electro-supply network are given and discussed.
The urgent problem for industrial inspection is non-contact precision measurement the diameters of circular reflecting
cylinders, namely, rolling bearing elements with diameter from 10 mm to 50 mm must be inspected with error no more
than 1 ìm. Diffraction method for measurement of diameters of circular reflecting cylinders is presented. Peculiarity of
this method is rather measurement gaps between two cylinder vertexes and two reference half-planes, than
measurement of cylinder diameter by direct Fraunhofer method. Equivalent model of formation of Fraunhofer
diffraction pattern by measurable object is developed. Using this model an algorithm of diffraction pattern processing
was suggested that allows determining gap between object edges and reference half-planes with error no more than 1ìm.
The inspection of geometrical parameters of through holes with different configurations is one of the urgent tasks in
industry. The majority of the existing noncontact inspection methods doesn't allow measuring the holes of complicated
(noncylindrical) configurations with good performances. Two simple developed methods based on diffractive optical
elements (DOEs) make possible to inspect the through holes (with the diameter from 5 to 100 mm) both cylindrical and
complicated configurations with acceptable lateral and axial (longitudinal) resolution. First method, based on the
scanning of inner hole surface by light ring, takes a mechanical displacement of the inspected article along its axis. The
second holes inspection method uses the DOE as the diffractive focuser, which generates N light rings simultaneously
along the hole axis with ring spacing &Dgr;z. In this case no need for mechanical displacement of inspected articles, output
image contains full measuring information about 3D article hole configuration. We have fabricated some binary DOEs
using circular laser writing system CLWS-300, developed and produced at the TDI SIE SB RAS. The obtained results
have been used under the development of universal automatic inspection system of nuclear reactors fuel assemblies
spacer grids.
The novel results of the R & D activity of TDI SIE SB RAS in the field of the optical measuring and laser technologies,
for solving safety problems in atomic and oil industry, as well as in railway transport are presented. 3D profilometer
with submicron and nanometer resolution using Linnik white-light interferometer and testing results of industrial
system for measuring surface defects of fuel elements are given. The metrological characterization of a perspective
Fresnel method for high precision measuring the dimensions of objects is investigated. Results of development and
testing the industrial system prototype for 3D inspection of nuclear grid spacers with micron resolution based on DOE
structured illumination are presented. We have developed an optical structured light method and an optical-electronic
system for automatic noncontact distant measurements of wear and defects detection for a contact wire electro-supply
network. For permanent noncontact bearing position inspection of oil-drilling platforms on Sakhalin coast (Russia) we
have developed optical-electronic method and produce system SAKHALIN. Experimental results and technical
performances are presented.
The novel results of the R & D activity of TDI SIE SB RAS in the field of the optical measuring technologies, as well as laser technologies for solving safety problems are presented. To measure the rocks stress and to prevent the mountain impact, as well as for basic investigations, a set of optical-electronic deformers and systems was developed and produced. For permanent noncontact bearing position inspection of oil-drilling platforms on Sakhalin coast (Russia) we have developed optical-electronic method and system SAKHALIN with cumulative traveled distance (3 km) measurement error less than 0.03 %. Multifunctional laser technological system LSP-2000 equipped by two Nd-YAG lasers was developed for cutting, welding and surface micro profiling with ablation process (working range of 3 × 2 × 0.6 m3, positioning error less than 10 mkm). Safety of Russian nuclear reactors takes 100 % noncontact 3D dimensional inspection of all parts of fuel assemblies, including grid spacers. Results of development and testing the specialized high productive laser measuring machine, based on structured illumination, for 3D inspection of grid spacers with micron resolution are presented. Ensuring the safety of running trains is the actual task for railways. Using high-speed laser noncontact method on the base of triangulation position sensors, TDI SIE has developed and produced automatic laser diagnostic system COMPLEX for inspection of geometric parameters of wheel pairs (train speed up to 60 km/hr.), which is used successfully on Russian railways. Experimental results on measuring and laser technological systems testing are presented.
The novel results of the R and D activity of TDI SIE SB RAS in the field of the optical measuring technologies, as well
as laser technologies for solving actual problems are presented. The metrological characterization of a perspective
Fresnel method for high precision measuring the dimensions of objects is investigated. An optoelectronic noncontact
method using diffractive optical element (DOE) for the 3D inspection of article holes is presented. A structured light
method and system testing results for noncontact inspection of wire wear and its defects for train electro-supply network
are discussed. For permanent noncontact bearing position inspection of oil-drilling platforms on Sakhalin coast (Russia)
under extreme temperatures (± 40°C) we have developed optical-electronic method and system SAKHALIN.
Multifunctional laser technological system LSP-2000 equipped by two Nd-YAG lasers was developed for cutting,
welding and surface micro profiling with ablation process (working range of 3 x 3 x 0.6 m3, positioning error less than
10 μm). Safety of Russian nuclear reactors takes 100 % noncontact 3D dimensional inspection of all parts of fuel
assemblies, including grid spacers. Results of development and testing the specialized high productive laser measuring
machine, based on structured illumination, for 3D inspection of grid spacers with micron resolution are presented. For
safety increasing of Russian railways TDI SIE has developed and produced automatic laser diagnostic system
COMPLEX for inspection of geometric parameters of wagon wheel pairs for running train (speed up to 60 km/hr.),
which is used successfully on Russian railways.
An optical structured illumination of 3D object as a light band method of wear measurement and defects detection of a contact wire network on railways, tram, trolleybus lines and similar systems of vehicles electro-supply is presented. The experimental device can extract main technological wire parameters, as its remaining height with rms value down to 0.1 mm. Also the cross-sectional area of the wire can be measured with rms area noise value of 1.5mm2, which is sufficient for confident decision-making related to the automatic wire wears and defects.
As it is known the mining of oil and gas offshore is carried out using the drilling platforms, which are extremely massive and inert. In order to avoid excessive stresses on platform, which is highly inertial object, it consists of few large parts (normally base and legs). Four friction pendulum bearings are used for mechanical link between the base and legs. The bearings functionality is to provide the protection of the platform from all possible mechanical loadings on the legs that might affect the base with the drill and other sensitive equipment. Mechanical loadings include different seismic movements, ice shifts, mechanical loadings during the drilling, heat expansion stress, etc. Bearings are worn out after certain distance traveled and have to be replaced when the movement resource is over. The most important parameter, which allows estimation the bearing resource, is measuring the cumulative distance traveled by the bearing from the beginning of its service with the relative accuracy better then 0.01%, and absolute displacement at ±350 mm range with accuracy better then 1 mm. For this purpose the automatic optical-electronic system for measurements of bearings movements was developed. Its main aim is continuous noncontact measurement of the bearing location and calculation of the total distance traveled by the bearing for any defined time period. Measuring principle of the system is based on optical image processing. The passive part of the system (optical target) is fixed on one part of construction while active part - a field measurement sensor (FMS) is installed on another part of construction that moves relative to the first one. The FMS continuously captures and processes the image of optical target. On the FMS output, after processing, the relative displacement between FMS and Optical Target is obtained with high degree of accuracy. The system was certified as a measuring tool as well as for the use in explosive environments (for gas and oil industry). It is designed for continuous 24-hours operation during 30 years.
KEYWORDS: Inspection, 3D modeling, Diffraction, Head, Laser systems engineering, Laser processing, Laser applications, 3D image processing, Control systems, 3D metrology
For solving of actual problems in material science, industry TDI STE SB RAS has developed some 3D opto-electromc
measuring technologies and systems for dimensional inspection. Applications and results of industrial testing of laser
measuring machine, opto-electronic shadow system and optical low-coherent radar as well as automatic laser diagnostic
systems, laser technological system for scientific and industrial applications are discussed.
For solving of actual problems in material science, industry TDI SIE SB RAS has developed some 3D opto-electronic measuring technologies and systems for dimensional inspection. Applications and results of industrial testing of laser measuring machine, opto-electronic shadow system and optical low-coherent radar as well as automatic laser diagnostic system for ensuring the safety in atomic and railway industry are discussed.
Precision noncontact measurement of diameters of circular reflecting cylinders is an actual problem in industry, especially under inspection of rollers of frictionless bearings with their diameters up to 50 mm with measurement error no more than 0.5 μm. We have developed differential Fraunhofer diffraction method, which is appropriate for measurement of such diameters. Peculiarity of this method is rather measurement of gaps between two cylinder vertexes and two reference half-planes, than measurement of cylinder diameter by direct Fraunhofer method.
Equivalent model for formation of Fraunhofer diffraction pattern by measurable object is presented. The proposed algorithm for processing of two diffraction patterns from gaps between cylinder vertexes and reference half-planes allows to determine objects diameter with inaccuracy of one- half micron. Experimental results are given.
The results of the R & D activity of TDI SIE SB RAS in the field of the 3D optical measuring technologies and systems for noncontact 3D optical dimensional inspection applied to atomic and railway industry safety problems are presented. This activity includes investigations of diffraction phenomena on some 3D objects, using the original constructive calculation method, development of hole inspection method on the base of diffractive optical elements.
Ensuring the safety of nuclear reactors and running trains as well as their high exploitation reliability requires a 100 % noncontact precise inspection of geometrical parameters of their components. To solve this problem we have developed methods and produced the technical vision measuring systems LMM, CONTROL, RADAR, and technologies for noncontact 3D dimensional inspection of grid spacers and fuel elements for the nuclear reactor VVER-1000 and VVER-440, as well as automatic laser diagnostic COMPLEX for noncontact inspection of geometric parameters of running freight car wheel pairs. The performances of these systems and the results of industrial testing are presented and discussed. The created devices are in pilot operation at Atomic and Railway Companies.
KEYWORDS: Inspection, Diffraction, 3D modeling, Control systems, 3D image processing, 3D metrology, Safety, Optical inspection, Laser development, Stereoscopy
The results of the R & D activity of TDI SIE SB RAS in the field of the 3D optical measuring technologies and systems for noncontact 3D optical dimensional inspection applied to atomic and railway industry safety problems are presented. This activity includes investigations of diffraction phenomena on some 3D objects, using the original constructive calculation method. The efficient algorithms for precise determining the transverse and longitudinal sizes of 3D objects of constant thickness by diffraction method, peculiarities on formation of the shadow and images of the typical elements of the extended objects were suggested. Ensuring the safety of nuclear reactors and running trains as well as their high exploitation reliability requires a 100% noncontact precise inspection of geometrical parameters of their components. To solve this problem we have developed methods and produced the technical vision measuring systems LMM, CONTROL, PROFIL, and technologies for noncontact 3D dimensional inspection of grid spacers and fuel elements for the nuclear reactor VVER-1000 and VVER-440, as well as automatic laser diagnostic COMPLEX for noncontact inspection of geometric parameters of running freight car wheel pairs. The performances of these systems and the results of industrial testing are presented and discussed. The created devices are in pilot operation at Atomic and Railway Companies.
A method of measuring the diameter of circular reflecting cylinders using the interference pattern which is formed when their surface is illuminated by a grazing plane monochromatic light beam. In the approximation of geometrical optics, the behavior of the recorded intensity distribution under inaccurate positioning of the cylinder measured has been studied, and it has been demonstrated that when the field is registered in a zone remote from its diametral plane, the criticity of the measuring scheme to longitudinal displacement of the object decreases noticeably. An analytical formula has been obtained which makes it possible to reconstruct the objects diameter by its interference pattern in the remote zone. For estimation ofthe influence oflight diffraction on the interference field, an equivalent model of field formation has been built according to which it may be regarded as a result of interference of a plane monochromatic wave and two point sources — a "floating" (on the objects surface) one and a stationary one, with ray and Fresnel type radiation patterns accordingly. As a result ofcalculations, it has been demonstrated that light diffraction on the cylinder influences noticeable the interference pattern which has to be taken into account when estimating the diameters of reflecting cylinders by the interference method with a high accuracy.
A short description of the largest radio heliograph in the word ? The Siberian Solar Radio Telescope (SSRT) is Presented. The modernization trends of the SSRT, whose purpose is to enlarge the Telescope capacities, including possibility to register three-dimensional structure and dynamics of active regions and Solar flares, are discussed. The main principles of building of a new radiation detector of the SSRT ? laser spectrum analyzer, based on acousto-optical cell were considered. It justifies the advisability of using laser triangulation range finder, performed on the diffraction optics elements, which allows to form laser beams with small angle of beam for improvement accuracy enhancement of the Radio Telescope antenna adjustment.
Oleg Bityutsky, I. Chapaev, V. Chernyshov, Yuri Chugui, A. Gushchina, Yu. Karlov, Konstan Kuchinsky, Vladimir Ladygin, Yu. Pimenov, Sergey Plotnikov, V. Rozhkov, Victor Vertoprakhov, V. Yunoshev, M. Zarubin
Ensuring a high reliability of fuel assemblies of nuclear reactors makes strict demands on geometric parameters of grid spacers. They determine the preset position of the fuel element beam in the transversal and longitudinal directions of fuel assembly and the required tension in the cell — fuel element junction, which is highly important for excluding of fuel element corrosion and for maintenance of normal thermal regime of this assembly. A laser measuring machine (LMM) using a three-channel measuring head based on multipoint structured illumination and scanning X-Y table, for 1 00% noncontact 3D inspection of grid spacers geometric parameters of Russian nuclear reactor VVER- 1000, has been developed and produced at TDI STE. The LMM structure, operation and software are described and the results of its industrial testing are presented and discussed. LMM makes it possible to measure for half an hour (with errors less than 18 ?m) the following grid spacer geometric parameters: diameters of its cells and of guiding channels, the distances between cells centers and shifts of cell centers relative to design drawing. In addition, LMM also measures grid spacer overall dimensions "for spanner".
A. Baybakov, Yuri Chugui, Yu. Karlov, K. Kascheev, K. Koutchinski, Vladimir Ladygin, V. Marchenko, A. Palekhin, Alexander Pastushenko, R. Pchelkin, Sergey Plotnikov, V. Rozhkov, M. Shindryaev, N. Tukubaev, Sergey Yunoshev, Yu. Zhukov
The optoelectronic systems for noncontact dimensional inspection of cylindrical items applied to atomic industry are presented. The structural schemes of the proposed systems, the technical performances and results of their practical application are given. Inaccuracy of measurements is ± 0.01 — ± 0.03 mm. The inspection capacity is a few hundreds of items per hour. At present these systems are under operating conditions as an integral part of the technological process of the atomic items production.
V. Beloglazova, Oleg Bityutsky, I. Chapaev, V. Chernyshov, Yuri Chugui, A. Gushchina, Yu. Karlov, Boris Krivenkov, Vladimir Ladygin, V. Nesin, Alexander Pastushenko, Yu. Pimenov, V. Rozhkov, Sergey Yunoshev, V. Yunoshev
Safety of nuclear reactor and ensuring their high exploitation reliability are urgent problems of nuclear power engineering. This requires a 1 00% noncontact precise productive inspection of geometrical parameters of fuel elements, including their cladding diameter, length and straightness. Optoelectronic devices "Control-i" and "Control-2" for automated noncontact dimensional inspection of fuel elements of Russian nuclear reactors VVER-1000 and VVER-440, incorporated to technological line of their production, are developed and produced at TDI STE. The measurement method using shadow technique, structural block-scheme, operation, software and metrological assurance of these devices are presented. Special attention is paid to the basic modules-measuring gages. As a result of industrial testing of these devices it has been established that diameter measurement error does not exceed 8 ?m, deviation from straightness is less than 15?m, and the length - 0,15 mm. The devices at present are in pilot industrial exploitation.
S. Avdeev, S. Bely, Yuri Chugui, V. Chuprov, O. Gudaev, I. Kanaev, V. Malinovsky, A. Makhrachev, A. Potashnikov, A. Pugachev, E. Schlufman, N. Surovtsev, V. Treshchikhin, A. Vedin, V. Vorobyev
A new technology for separation of diamonds is proposed: a combined use of the Rayleigh and Ramanlight Scattering in a two-stage separator. A brief description of various units for detection is given. Results of work on development and experimental checking of such a separator are presented. The method of laser-aided separation of diamonds based on the principle of elastic (without any frequency shift) light scattering has no analogs and is protected by a patent.
Profile measurement of the surface defects (with the depth of dozens of microns), based on the low-coherent interferometry, is discussed in this paper. The major challenge for production of such devices is selecting interference fields, which are used to determine the isolines of the defect depth. A direct way to find low- contrast interference fields in a large dynamic light range appears to be an extremely difficult procedure. We propose an effective interference fields localization technique based on the reference wave phase modulation that against others provides high measurement accuracy and reliability. The reconstructed 3D-image and depth isoline map of 50 micrometers deep defect on the metallic surface of the fuel element are also presented. The system for surface profile measurement with the following characteristics has been developed: surface reconstruction error is less than 2 micrometers , surface reconstruction range on depth is up to 10 mm.
KEYWORDS: Diffraction, 3D image processing, 3D modeling, Image filtering, Optical filters, Far-field diffraction, Optical signal processing, 3D metrology, Inspection, 3D acquisition
Constructive method for the formation and filtering Fraunhofer diffraction patterns and images of volumetric objects has been developed applied to 3-D measuring technologies for noncontact dimensional inspection. This method is simple, physically obvious and at the same time, sufficiently strict for engineering applications. It is based on the model of equivalent diaphragms, according to which the problem of light diffraction on volumetric bodies is reduced to the analysis of diffraction phenomena on the plane diaphragms using the Kirchhoff-Fresnel approximation. Dependencies between the characteristic parameters of the diffraction patterns and geometric dimensions of 3-D typical objects were found. Suggested efficient algorithms allow by corresponding processing of diffraction patterns to determine transverse and longitudinal sizes of extended objects with the errors 0.1 percent and 1 percent, respectively. Peculiarities of coherent optical processing the 3-D objects are investigated by the example of high- frequency filtering (contouring) of volumetric edges with perfectly absorbing and reflecting inner surfaces. Results of the investigations showed a satisfactory agreement of the theoretical and experimental data.
The results of development of noncontact optico-electronic real time system for integral dimensional inspection of atomic reactor parts, as hollow cylinders made of soft alloy, are given. This cheap, reliable and robust system for the industrial operation is based on shadow method for measuring the outside diameter and straightness deviation as well as on the triangulation method for measuring the inside diameter. For the shadow method the main sources of errors are caused by the influence of volumetric properties of 3D objects on the structure of shadow image, the inaccuracy of approximation of object's edge position caused by linear photodiode array as well as the aberration of optical system. By choosing type of the optical system and using look-up table algorithm for aberration correction as well as the cubic approximation of object's edge profile under its reconstruction allows to reduce the maximal total error up to 2 micrometer when the speed of measurement is 500 Hz. The optimization of triangulation system parameters under operation with technical (machined) surface objects in a real hard workshop conditions (high temperature range, dust) was made. The using hardware signal processor for median algorithm data processing is optimal as to the accuracy and frequency response of measurement. The developed system allows inspection articles with outside diameter up to 50 mm, inside diameter 43 mm, length -- up to 150 mm, straightness deviation equal to 0,3 mm with errors 0.014 mm for diameters, 0.040 mm for length and 0.020 mm for straightness deviation. At present the system is operating on the technological conveyer line for real time inspection of atomic reactor details (loading and unloading are made by manipulator) on the nuclear enterprise.
Bases of constructive theory of formation in coherent light of the Fraunhofer diffraction (Fourier spectrum) patterns of the opaque 3D objects of constant thickness with flat internal surfaces are presented. Such theory is simple, physical obvious and at the same time sufficiently strict. It is based on the model of the equivalent diaphragms according to which the problem of light diffraction on volumetric bodies is reduced to the analysis of diffraction phenomena on the plane transparencies which are located in space. It permits to apply the standard Fourier-optical methods for the calculation in Kirchhoff-Fresnel approximation. This theory is developed and generalized for cases of formation and filtering the images and Fraunhofer diffraction patterns of the typical elements of extended bodies, including volumetric edge, 3D slit. Dependencies between the characteristic parameters of the diffraction patterns and geometrical dimensions of 3D slit are found on the basis of the behavior of the Fourier spectra of extended objects. Peculiarities of coherent optical processing of 3D objects are investigated in detail by the example of high-frequency filtering (contouring) of volumetric edge with absorbing, reflecting and grey inner surfaces.
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