• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A method for identifying timber surface properties by using linearly polarized light. The polarization plane of the incident radiation is selected according to the object. The intensity components Imin and Imax having perpendicular polarization planes of the scattered radiation are measured, where the polarization plane of the component Imax is the same as that of the incident radiation. On the basis of the quantities Imin and <IMAGE> conclusions are drawn about the surface properties of the examined surface.
    公开号:SU1170978A3
    申请号:SU823390754
    申请日:1982-02-09
    公开日:1985-07-30
    发明作者:Хирвонен Куллерво；Каронен Аймо
    申请人:Алтим Контрол Кю (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to a method for determining the surface properties of industrial wood, in particular pilmarmagoshov and plywood, in determining defects and quality.
    Timber and plywood used for various purposes are classified according to the surface properties of the product. The factors that determine quality (and strength) are knots, burl, blue, wane, fiber distortions, malnutrition, and mechanical defects. The price of the board and plywood material is determined by the quality classification.
    The known methods for determining the surface properties or defects of wood are based on the construction of a surface of the intensity of radiation scattered from a surface or passing through a surface on which electromagnetic radiation is directed using special geometric devices. Depending on the radiation source, various light and radiation detectors, as well as video cameras and diode array cameras, are used for detection.
    The known method for determining the quality of wood is based on the measurement of the scattered polarized radiation of radio frequencies jQ.
    The disadvantages of this method are implementation complexity and low accuracy.
    The closest in technical essence to the present invention is a method for determining the quality of wood, including illuminating the surface of the wood with linearly polarized optical radiation, measuring the parameters of scattered radiation and determining the quality based on the results of measuring Y.
    The disadvantage of this method is low accuracy in determining the quality of wood.
    The aim of the invention is to improve the accuracy. .
    To achieve this goal, according to the method of determining the quality of wood, including the illumination of the wood surface with monochromatic linearly polarized optical radiation, measurement of the scattered radiation and
    determining the quality based on the measurement results, the illumination is carried out by radiation with a polarization plane parallel to or perpendicular to the direction of growth of the wood fibers, the intensities of the components of the scattered radiation are measured with the polarization planes of the illuminating radiation, respectively, and orthogonal to wood quality is determined by comparing
    sizes 3
    3
    max I
    min
    -X
    .MOX.
     qing
    with appropriate values for defect-free wood.
    In addition, the most rational lighting and measurement of scattered radiation should be no more than 15 at an angle to the normal to the surface of wood when measured in the direction of fiber growth and no more than 50 when measured in the orthogonal direction.
    The radiation reflected from the wood is scattered. Defects that occur in wood (e.g. knots, burr, skew texture) create depolarization that is different from depolarization created by high-quality wood, and which can be used for automatic recognition of these defects. It is particularly important that the orientation of the fibers also reflects depolarization (distortion of the texture, transverse texture, and knots), which allows the proposed method to be used to measure the strength of wood.
    The degree of depolarization P is connected in a certain way with the direction of the fibers on the wood surface, as well as with the appearance of certain defects, such as holes. The physical basis of this depolarization property seems to be related to the dielectric constant of wood, the value of which varies in the direction of growth of the wood and in the radial and tangential directions of the cross section. Other reasons may be the double refraction and optical activity. However, theoretical - there is no justification described.
    3
     The kits L / II1 are measured by radiation scattered by the wood surface in a known manner, using as an analyzer polarization filters or a prism that splits the radiation into two components (for example, the Wollaston prism). When using cameras, depolarization can be measured by placing cameras like this; in such a way that the object is in the same position in their image plane, and using polarization filters together with their lenses, as well as synchronously comparing the intensities of the image plane. Depolarization can be described by the formula
    max min
    ICG5 JyQKC - «AI
    where D j, (.3, „) is the maximum (minimum) intensity given by the detector and obtained by rotating the analyzer filter before the detector ppf. The range is from O (fully depolarized radiation) to 1 (linearly polarized radiation).
    Depolarization depends to a significant extent on the wavelength, so the wavelengths used must be selected based on the measurements for each application. The results are also influenced by the direction of the polarization plane of linearly polarized electromagnetic radiation directed at the surface, therefore the optimal direction of the polarization plane should be chosen based on the measurements.
    The measurements showed that the optimum wavelength for wood (sawn wood and plywood) was 632.8 nm (the wavelength is helium; a single laser) and that the best direction of the polarization plane of the incident radiation is parallel to the direction of wood growth. The light scattered by the quality surface of the wood is partially depolarized, and the light scattered from the bitch is almost completely depolarized. Prul causes less depolarization than high-quality wood. As follows from the tests performed, the proposed method is applicable to the study of both dry and wet wood.
    709784
    The fluctuations of the properties, the surface of high-quality wood are so great that the traditional construction of the intensity plane 3 is unsuitable for research. However, using linearly polarized radiation of the intensity component 3 jujii, associated with depolarization, can be used. It is practically not affected by, for example, the structure of annual rings (specular reflections present in component 3 40X), the surface roughness or skewed text 5 ry. Changes are manifested in a decrease in the intensity plane, where there are defects (knots, prellum, wood blueness, cracks, scariness, worms, etc.). 20 Also use the intensity component 3 when comparing the intensity levels, when the level of reference is the magnitude of this component on a high-quality, or defect-free surface.
    In combination with the data obtained in this way, the intensity data and the degrees of depolarization of the scattered radiation, determine the quality, at 0 this requires a relatively small computing power of the computer.
    By measuring only the intensity (for example, L or min components), the same measurement values are obtained for defects such as prell, knots, and blue, resulting in additional data being needed to confirm the findings. This data is obtained, for example, by means of pattern recognition, for which a large computational power of the computer is required.
    According to the degree of depolarization, quality wood, preliness and knots can be distinguished from each other, and a strong distortion of texture and knots fall into one class and, for example, high-quality wood, blueness, discoloration and bark fall into one class.
    The proposed method is based on the simultaneous use of the intensity components f инinl max and the degree of polarization P. With this, in comparison with the known methods in which image recognition is used, in the proposed method, the need for data processing and in the capacity of these devices is much less.
    The test object should be illuminated with linearly polarized, usually relatively monochromatic, light or radiation. Therefore, a polarizer should be placed in front of the light source. Laser light, depending on the type of laser, is either naturally polarized or easily polarized. In addition, systems that can be used for one- or two-dimensional deflection are being installed by the industry to examine the entire surface. Taking into account - the natural direction of movement of plywood sheets, a one-dimensional deflection is enough to examine their surface. It is most natural to explore lumber surfaces by moving wood in the longitudinal direction.
    FIG. 1 shows a diagram of an apparatus for carrying out the proposed method; in fig. 2 shows an embodiment of the device, fig. 3 is a diagram illustrating the examination of the surface of the lumber V in FIG. 4 and 5 are examples of the intensity curve obtained by measuring the surface of a wood, corresponding to the corresponding degree of depolarization.
    In the measuring device (Fig. 1) a beam of light from a laser is directed to the surface 2 of the object under study. The direction of the incident beam and the direction perpendicular to the surface, form the angle dC. Part 3 of the scattered reflected radiation passes through the polarization filter 4 to the detector 5 and part 6 through the polarization filter.
    7 on the detector 8. The directions of the reflected radiation and the direction perpendicular to the surface will form the angles j Angles 9 (, ftj t flz are preferably equal to about 15 maximum when measured in the direction of growth of wood and about 50 maximum in the direction perpendicular to it.
    The transmission directions of the polarized filters are angled to each other in such a way that the transmission direction of the detector 8 is parallel to the polarization plane of the floating radiation. Signals of intensity and enter the processor 9, in which they are converted into a form convenient for
    determine the quality of wood.
    In the circular variant (Fig. 2), part 10 of the reflected radiation passes through the prism of Wollaston 11, divided into polarization components
    12 and 13, to detectors 14 and 15, which measure the intensity of J / mtif; moss
    The principal design of the devices designed by the R & D survey. The board is shown on 4wr. 3. The light beam 1 with the help of a swinging deflecting mirror 17 is conducted on the surface 18 of wood in the transverse direction of the board along the path 19. The board is shifted in the longitudinal direction. Radiation reflected from the surface of the board is detected using the means shown in FIG. 1 or FIG. 2
    Thus, the proposed method allows to simplify the measurements and improve the accuracy of determining the quality of wood.
    /four
    J / 2 Wv Imi
    .2
    权利要求:
    Claims (2)
    [1]
    1. METHOD FOR DETERMINING WOOD QUALITY, including illuminating a wood surface with monochromatic linearly polarized optical radiation, measuring the parameters of scattered radiation and determining the quality from the measurement results, characterized in that, in order to improve accuracy, the illumination is carried out by radiation. With a plane of polarization parallel or perpendicular growth direction of wood fibers measured intensity component and J MI) one of the scattered light with polarization planes respectively parallel and second orthogonal plane of polarization of the illuminating radiation, and determine the quality of wood by comparing the quantities J max 2 min and rf "f ™ with corresponding values for a defect-free timber.
    [2]
    2. The method according to π. 1, characterized in that the illumination and measurement of scattered radiation is carried out at an angle to the normal to the surface of the wood no more than 15 ° when measured in the direction of fiber growth and not more than 50 ° when measured in the orthogonal direction.
    . SU 1170978
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    同族专利:
    公开号 | 公开日
    AT394780B|1992-06-25|
    NO152354C|1985-09-11|
    DE3200810C2|1993-04-29|
    FI63835C|1983-08-10|
    DE3200810A1|1982-08-19|
    FI63835B|1983-04-29|
    FI810371L|1982-08-11|
    US4482250A|1984-11-13|
    FR2499717B1|1985-04-12|
    NO820379L|1982-08-11|
    SE8200407L|1982-08-11|
    CA1168892A|1984-06-12|
    NO152354B|1985-06-03|
    ATA38182A|1991-11-15|
    SE455023B|1988-06-13|
    FR2499717A1|1982-08-13|
    引用文献:
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    CH447630A|1965-06-16|1967-11-30|Hitachi Ltd|Method for the detection of irregularities on the surface of an object and apparatus for carrying out this method|
    US3474254A|1968-02-26|1969-10-21|Sick Erwin|Photoelectronic apparatus for scanning textile material|
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    US3992571A|1973-05-11|1976-11-16|National Research Development Corporation|Differential optical polarization detectors|
    GB1488841A|1974-01-18|1977-10-12|Plessey Co Ltd|Optical detection apparatus|
    SE385048B|1974-08-05|1976-05-31|Svenska Traeforskningsinst|PROCEDURE FOR SATURATING THE TOPOGRAPHY OF A SURFACE|
    DE2534023C2|1975-07-30|1985-03-14|Plessey Overseas Ltd., Ilford, Essex|Method for detecting defects in sawn or planed wood and device for carrying out the method|
    US4030830A|1976-01-05|1977-06-21|Atlantic Research Corporation|Process and apparatus for sensing defects on a smooth surface|
    GB1580196A|1976-05-27|1980-11-26|Ferranti Ltd|Gloss measuring surface inspection systems|
    FI57490C|1978-06-01|1980-08-11|Innotec Oy|FOERFARANDE FOER BESTAEMNING AV SNEDFIBRIGHETEN I VIRKE I SYNNERHET I SAOGAT VIRKE|
    JPS55116211A|1979-02-28|1980-09-06|Matsushita Electric Works Ltd|Inspection for checkered pattern|US4606645A|1984-10-29|1986-08-19|Weyerhaeuser Company|Method for determining localized fiber angle in a three dimensional fibrous material|
    FI74815C|1986-01-20|1988-03-10|Altim Control Ky|Procedure for identifying the surface properties of a wood surface.|
    US4893932B1|1986-05-02|1992-10-20|Particle Measuring Syst|
    US4916629A|1987-06-26|1990-04-10|Weyerhaeuser Company|Method for determination of pith location relative to lumber surfaces|
    US4831545A|1987-06-26|1989-05-16|Weyerhaeuser Company|Method for determination of pith location relative to lumber surfaces|
    US4890926A|1987-12-21|1990-01-02|Miles Inc.|Reflectance photometer|
    JPH0774788B2|1988-03-28|1995-08-09|株式会社堀場製作所|Foreign substance presence inspection device|
    US4919534A|1988-09-30|1990-04-24|Environmental Products Corp.|Sensing of material of construction and color of containers|
    US4972091A|1989-05-16|1990-11-20|Canadian Patents And Development Limited/Societe Canadienne Des Brevets Et D'exploitation Limitee|Method and apparatus for detecting the presence of flaws in a moving sheet of material|
    SE466420B|1989-11-14|1992-02-10|Svenska Traeforskningsinst|PROCEDURE AND DEVICE FOR THE DETECTION OF BARK AND DETERMINATION OF BARKING RATE BY WOOD OR TIP|
    US5102222A|1990-02-08|1992-04-07|Harmonic Lightwaves, Inc.|Light wave polarization determination using a hybrid system|
    FR2665959B1|1990-08-16|1994-01-14|Oreal|APPARATUS FOR ASSESSING THE SHINE OF A SURFACE, PARTICULARLY SKIN.|
    US5244814A|1991-05-20|1993-09-14|Forintek Canada Corporation|Decay detection in wood|
    DE4317513A1|1993-05-26|1994-12-01|Select Ingenieurgesellschaft F|Method and device for selective separation of bodies and use of the method|
    FR2707007B1|1993-06-24|1995-08-25|France Etat Armement|
    US5502559A|1993-11-01|1996-03-26|Environmental Products Corporation|Apparatus and method for detection of material used in construction of containers and color of same|
    GB2285861A|1994-01-19|1995-07-26|Peter Charles Matthews|Optical detection of grain defects in lumber|
    JP3358099B2|1994-03-25|2002-12-16|オムロン株式会社|Optical sensor device|
    US5835220A|1995-10-27|1998-11-10|Nkk Corporation|Method and apparatus for detecting surface flaws|
    US5742392A|1996-04-16|1998-04-21|Seymour Light, Inc.|Polarized material inspection apparatus|
    US6624883B1|2000-09-28|2003-09-23|National Research Council Of Canada|Method of and apparatus for determining wood grain orientation|
    US7549367B2|2004-01-20|2009-06-23|Utah State University Research Foundation|Control system for a weapon mount|
    CA2478757A1|2004-08-06|2006-02-06|Mario Talbot|Detection of blue stain and rot in lumber|
    DE102005021649B4|2005-05-06|2007-04-12|Tropf, Hermann|Optical height scanning of a surface|
    CA2737326C|2008-10-03|2013-01-08|Fpinnovations|Apparatus and methods for controlled debarking of wood|
    US8780360B2|2009-07-15|2014-07-15|Microtec S.R.L.|Method and apparatus for identifying the orientation of wood fibres|
    FR2994263B1|2012-08-02|2018-09-07|Vit|METHOD AND DEVICE FOR IDENTIFYING MATERIALS IN A SCENE|
    EP3528047A1|2018-02-14|2019-08-21|ASML Netherlands B.V.|Method and apparatus for measuring a parameter of interest using image plane detection techniques|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    FI810371A|FI63835C|1981-02-10|1981-02-10|FOERFARANDE FOER IDENTIFIERING AV ETT VIRKES YTEGENSKAPER|
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