JP5793669B2 - 3D measuring apparatus and 3D measuring method - Google Patents

Description

  The present invention relates to a three-dimensional measurement apparatus and a three-dimensional measurement method.

  Conventionally, a three-dimensional measuring apparatus for measuring a three-dimensional shape of a workpiece has been proposed (for example, Patent Document 1).

  FIG. 14 shows a configuration of a conventional three-dimensional measurement apparatus B1. The three-dimensional measurement apparatus B1 includes an illumination unit 501, a linear polarizing plate 502, a camera 503, a three-dimensional calculation unit 504, and a display unit 505. Composed.

  The illumination unit 501 has a hemispherical bowl-shaped irradiation surface 501a, and irradiates a workpiece W disposed substantially at the center of the opening of the irradiation surface 501a with circularly polarized irradiation light L501. The reflected light L502 reflected by the irradiation light L501 on the surface of the workpiece W changes to elliptically polarized light, and passes through the linear polarizing plate 502 through the hole 501b provided at the bottom center of the irradiation part 501. The transmitted light L503 transmitted through the linearly polarizing plate 502 changes to linearly polarized light, and the transmitted light L503 is captured by the camera 503. The three-dimensional calculation unit 504 acquires imaging data of the camera 503, measures the three-dimensional shape of the workpiece W based on the imaging data, and the measurement result is obtained as shape data such as an external view and dimensions, as a liquid crystal screen or the like. Are displayed on the display unit 505.

  Specifically, each time the camera 503 captures the transmitted light L503, the linearly polarizing plate 502 rotates by a predetermined angle in the circumferential direction of the central axis of the plate surface and changes the polarization direction stepwise. The imaging operation of the camera 503 and the rotation operation of the linear polarizing plate 502 are repeated until the linear polarizing plate 502 is rotated half a turn (180 ° rotation).

  The three-dimensional calculation unit 504 acquires imaging data of the transmitted light L503 corresponding to each of the rotation angles of the linear polarizing plate 502 from the camera 503, and the rotation angle (polarizing plate angle) of the linear polarizing plate 502 and the surface of the workpiece W are obtained. A relationship with the luminance of the pixel (pixel luminance) is derived. As shown in FIG. 15, the relationship between the polarizing plate angle and the pixel luminance is such that the pixel luminance increases or decreases with a period of 180 ° of the polarizing plate angle, and the pixel luminance is a maximum value and a minimum value between the polarizing plate angles of 0 to 180 °. Each value appears one by one.

  Then, the three-dimensional calculation unit 504 performs polarization analysis of the transmitted light L503 for each pixel based on the relationship between the polarizing plate angle and the pixel luminance, and detects the polarization state for each pixel. The pixel subjected to the polarization analysis corresponds to a small part Sn (surface piece Sn) on the surface of the workpiece W, and the inclination angle of the normal vector N of the surface piece Sn shown in FIG. θa and azimuth angle θb are obtained. The tilt angle θa is the angle of the normal vector N with respect to the imaging center axis Z of the camera 503, and the azimuth angle θb is the angle of the normal vector N with respect to the X axis on the XY plane orthogonal to the imaging center axis Z. It is.

  The three-dimensional calculation unit 504 determines the inclination of the surface piece Sn based on the inclination angle θa and the azimuth angle θb of the normal vector N obtained as described above. Then, the image analysis process is performed for each pixel to determine the inclination of the surface piece Sn, and the three-dimensional shape of the workpiece W is measured by making these surface pieces Sn continuous.

International Publication No. 2010/021148

  However, the conventional three-dimensional measuring apparatus B1 has the following problems when the workpiece W1 having the shape shown in FIGS. 3 and 4A and 4B is a measurement target.

  First, the workpiece W1 is a trapezoid whose end faces M3 and M4 (in FIG. 3, FIG. 4 (a) and FIG. 4 (b) only show one end face M3) facing each other in the Y-axis direction are shorter than the lower base. It becomes a shape. Further, the side surfaces facing each other in the X-axis direction are configured by an inclined surface M1 inclined in one direction and M2 inclined in the other direction, and an inner angle formed between the inclined surfaces M1 and M2 with respect to the XY plane is , “45 °”. The imaging center axis Z of the camera 503 is assumed to coincide with the normal direction of the upper surface M5 of the workpiece W1.

  Then, the three-dimensional calculation unit 504 derives the inclination angle θa501 and the azimuth angle θb501 of the normal vector N1 of the inclined surface M1 and the inclination angle θa502 and the azimuth angle θb502 of the normal vector N2 of the inclined surface M2 by polarization analysis.

  Here, when one direction of the Z axis is an inclination angle θa = 0 ° and one direction of the X axis is an azimuth angle θb = 0 °, the inclination direction of the inclined surface of the workpiece W viewed from the camera 3 is the inclination angle θa. The range of “−90 ° to 90 °” and the azimuth angle θb “0 ° to 360 °” can be arbitrarily set. However, the ranges of the tilt angle θa and the azimuth angle θb that can be obtained by the three-dimensional calculation unit 504 using a polarization analysis technique such as a rotation analyzer method are the tilt angle θa “0 ° to 90 °” and the azimuth angle θb. “0 ° to 180 °”.

  Therefore, there is a problem that the inclination angle θa501 and the azimuth angle θb501 obtained by the polarization analysis and the inclination angle θa502 and the azimuth angle θb502 obtained by the polarization analysis become the same value.

  For example, as shown in FIG. 17, the inclination angle θa501 of the normal vector N1 of the inclined surface M1 derived by the three-dimensional calculation unit 504 is “45 °”, and the azimuth angle θb501 is “0 °”. On the other hand, the inclination angle θa502 of the normal vector N2 of the inclined surface M2 derived by the three-dimensional calculation unit 504 is also “45 °”, and the azimuth angle θb502 is also “0 °”. That is, although the normal vectors N1 and N2 of the inclined surfaces M1 and M2 are actually formed in different directions, the analysis results as if the normal vectors N1 and N2 are formed in the same direction. become.

  As described above, the normal vector N (see FIG. 16) of the surface piece Sn cannot be uniquely determined by the inclination angle θa and the azimuth angle θb obtained by the polarization analysis. Therefore, in the conventional three-dimensional measuring apparatus B1, the difference between the inclined directions of the inclined surfaces M1 and M2 cannot be identified, and the inclined surfaces M1 and M2 cannot be distinguished.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide a three-dimensional measurement apparatus and a three-dimensional measurement method that can identify differences in inclination directions of a plurality of inclined surfaces using polarization analysis. There is to do.

Three-dimensional measurement apparatus of the present invention, the bowl-shaped irradiation surface of a hemisphere, a lighting device for morphism the first light to the surface of the circular polarization of the object to be measured which is located approximately at the center of an opening of the irradiated surface irradiation, An imaging device that generates imaging data obtained by imaging the second light formed by reflecting the first light on the surface of the measurement object, and a relative relationship between the imaging direction of the imaging device and the surface of the measurement object An attitude changing means for changing the angle, and a polarization state of the elliptically polarized light of the second light based on the imaging data generated by the imaging apparatus with the relative angle set to the first state by the attitude changing means And detecting the first tilt angle and the first azimuth angle of the surface of the object to be measured based on the detected polarization state, and the posture changing means The relative angle is changed from the first state to the second state. On the basis of the imaging data to which the imaging device is generated after the detected azimuth and ellipse angle of the polarizing ellipse polarization state of elliptically polarized light of the second light, based on the polarization state of this detection, the The second inclination angle and the second azimuth angle of the surface of the object to be measured are obtained, and the first inclination angle is corrected based on the difference between the first inclination angle and the second inclination angle 3 A three-dimensional calculation unit, wherein the three-dimensional calculation unit determines the positive or negative sign of the first inclination angle according to a difference between the first inclination angle and the second inclination angle. The first tilt angle is corrected .

The three-dimensional measurement apparatus of the present invention includes a lighting device that irradiates a circularly polarized first light from a hemispherical bowl-shaped irradiation surface to a surface of an object to be measured disposed at a substantially center of an opening of the irradiation surface; An imaging device that generates imaging data obtained by imaging the second light formed by reflecting the first light on the surface of the measurement object, and a relative angle between the imaging direction of the imaging device and the surface of the measurement object And changing the relative angle to the first state by the posture changing means to change the elliptical polarization state of the second light based on the imaging data generated by the imaging device. An azimuth angle and an ellipticity ratio of the polarization ellipse are detected, and based on the detected polarization state, a first tilt angle and a first azimuth angle of the surface of the object to be measured are obtained, and the relative change is performed by the posture changing means. The angle is changed from the first state to the second state. After that, based on the imaging data generated by the imaging device, the azimuth angle and ellipticity ratio of the polarization ellipse are detected as the polarization state of the elliptically polarized light of the second light, and based on the detected polarization state, the The second inclination angle and the second azimuth angle of the surface of the object to be measured are obtained, and the first azimuth angle is corrected based on the difference between the first inclination angle and the second inclination angle 3 A three-dimensional calculation unit, wherein the three-dimensional calculation unit shifts the first azimuth angle by 180 degrees according to a difference between the first inclination angle and the second inclination angle. The azimuth angle is corrected.

In this invention, it is preferable that the posture changing means changes the relative angle between the imaging direction of the imaging device and the surface of the measurement object by rotating the measurement object.

In this invention, it is preferable that the posture changing means changes the relative angle between the imaging direction of the imaging device and the surface of the object to be measured by rotating the imaging device.

The three-dimensional measurement method of the present invention irradiates the surface of the object to be measured, which is arranged at the approximate center of the opening of the irradiation surface, from the hemispherical bowl-shaped irradiation surface, and applies the first polarized light. Imaging data obtained by imaging the second light formed by the reflection of the first light on the surface of the image is generated, the polarization state of the second light is detected based on the imaging data, and the detected polarization In the three-dimensional measurement method for obtaining the tilt angle and azimuth angle of the surface of the object to be measured based on the state, the relative angle between the imaging direction in which the second light is imaged and the surface of the object to be measured is a first angle. An azimuth angle and an ellipticity rate of a polarization ellipse are detected as the polarization state of the elliptically polarized light of the second light based on the imaging data generated by setting the state, and based on the detected polarization state, the object to be covered is detected. A step of obtaining a first inclination angle and a first azimuth angle of the surface of the measurement object Based on the imaging data generated after changing the relative angle from the first state to the second state, the azimuth angle and ellipticity ratio of the polarization ellipse as the polarization state of the elliptically polarized light of the second light And determining the second tilt angle and the second azimuth angle of the surface of the object to be measured based on the detected polarization state, the first tilt angle and the second tilt angle, And correcting the first tilt angle by determining the sign of the first tilt angle in accordance with the difference between the first tilt angle and the first tilt angle.

Three-dimensional measurement method of the present invention, the bowl-shaped irradiation surface of a hemisphere, shines irradiation the first circularly polarized light to the surface of the object to be measured which is located approximately at the center of an opening of the irradiated surface, the object to be measured The imaging data obtained by imaging the second light formed by reflecting the first light on the surface of the object is generated, the polarization state of the second light is detected based on the imaging data, and the detected In the three-dimensional measurement method for obtaining the tilt angle and azimuth angle of the surface of the object to be measured based on the polarization state, the relative angle between the imaging direction for imaging the second light and the surface of the object to be measured is a first angle. Based on the imaging data generated by setting to the state of, the azimuth angle and ellipticity ratio of the polarization ellipse as the polarization state of the elliptically polarized light of the second light, and based on the detected polarization state, A step of obtaining a first inclination angle and a first azimuth angle of the surface of the measurement object , Said relative angle from the first state based on said imaging data generated after changing to the second state, azimuth and ellipse angle of the polarizing ellipse polarization state of elliptically polarized light of the second light And determining the second tilt angle and the second azimuth angle of the surface of the object to be measured based on the detected polarization state, the first tilt angle and the second tilt angle, And correcting the first azimuth angle by shifting the first azimuth angle by 180 ° in accordance with the difference between the first azimuth angle and the first azimuth angle .

  As described above, according to the present invention, there is an effect that a difference in each inclination direction of a plurality of inclined surfaces can be identified while using ellipsometry.

1 is a configuration diagram illustrating a three-dimensional measurement apparatus according to Embodiment 1. FIG. It is a perspective view which shows the same inclination angle and azimuth. It is a perspective view which shows a workpiece | work same as the above. (A) (b) It is a top view which shows the workpiece | work same as the above. (A) (b) It is a top view which shows the 1st state same as the above. (A) (b) It is a top view which shows the 2nd state same as the above. (A)-(c) It is a table figure which shows the measured value and correction value of an inclination angle and azimuth angle same as the above. (A) (b) It is a top view which shows the 1st state using the other workpiece | work same as the above. (A) (b) It is a top view which shows the 2nd state same as the above. (A)-(c) It is a table figure which shows the measured value and correction value of an inclination angle and azimuth angle same as the above. (A)-(c) It is a table figure which shows the measured value and correction value of the inclination angle and azimuth of Embodiment 2. (A)-(c) It is a table figure which shows the measured value and correction value of an inclination angle and an azimuth using the other workpiece | work same as the above. It is a block diagram which shows the three-dimensional measuring apparatus of Embodiment 3. It is a block diagram which shows the conventional three-dimensional measuring apparatus. It is a graph which shows the relationship between a polarizing plate angle and pixel luminance. It is a perspective view which shows the conventional inclination angle and azimuth. It is a table figure which shows the measured value of the conventional inclination angle and azimuth.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration of a three-dimensional measurement apparatus A1 of this embodiment. The three-dimensional measurement apparatus A1 includes an illumination unit 1, a linearly polarizing plate 2, a camera 3 (imaging device), a three-dimensional calculation unit 4, and the like. The display unit 5 and the work pedestal 6 (posture changing means).

  The illuminating unit 1 has a hemispherical bowl-shaped irradiation surface 1a, and applies circularly polarized irradiation light L1 (first light) to a workpiece W (measurement object) arranged at the approximate center of the opening of the irradiation surface 1a. Irradiate. The reflected light L2 reflected from the surface of the work W by the irradiation light L1 changes to elliptically polarized light and passes through the linearly polarizing plate 2 through the hole 1b provided at the bottom center of the irradiation part 1. The transmitted light L3 (second light) transmitted through the linearly polarizing plate 2 changes to linearly polarized light, and the camera 3 images the transmitted light L3. The three-dimensional calculation unit 4 acquires the imaging data of the camera 3, measures the three-dimensional shape of the workpiece W based on the imaging data, and the measurement result is obtained as shape data such as an external view and dimensions, as a liquid crystal screen or the like. Are displayed on the display unit 5. Note that the three-dimensional measuring apparatus A1 includes light guide means (not shown) that guides the reflected light L2 to the hole 1b.

  The three-dimensional calculation unit 4 includes an inclination calculation unit 41 and an inclination correction unit 42.

  The inclination calculation unit 41 performs rotation control of the linear polarizing plate 2 and imaging control of the camera 3, and rotates the linear polarizing plate 2 by a predetermined angle in the circumferential direction of the central axis of the plate surface to change the polarization direction stepwise. While changing, the camera 3 captures the transmitted light L3 in each polarization direction of the linearly polarizing plate 2. That is, the inclination calculating unit 41 acquires the imaging data of the transmitted light L3 corresponding to each rotation angle of the linear polarizing plate 2 from the camera 3, and performs the imaging operation of the camera 3 and the rotational operation of the linear polarizing plate 2, The process is repeated until the linearly polarizing plate 2 rotates halfway (180 °).

  Then, the inclination calculation unit 41 derives the relationship between the rotation angle of the linearly polarizing plate 2 (polarizing plate angle) and the luminance of the pixels on the surface of the workpiece W (pixel luminance). The inclination calculation unit 41 performs polarization analysis of the transmitted light L3 for each pixel based on the relationship between the polarizing plate angle and the pixel luminance, and detects the polarization state for each pixel. As a method for detecting the polarization state, a “rotation analyzer method” for detecting the azimuth angle and ellipticity ratio of the polarization ellipse is used. Note that the rotation analyzer method is a well-known ellipsometric technique and will not be described in detail.

  The pixel subjected to the polarization analysis corresponds to a small part Sn (surface piece Sn) of the surface of the workpiece W, and the inclination calculating unit 41 calculates the normal vector of the surface piece Sn shown in FIG. N inclination angle θa and azimuth angle θb are obtained. The tilt angle θa is the angle of the normal vector N with respect to the imaging center axis Z (hereinafter referred to as the Z axis) of the camera 3, and the azimuth angle θb is X on the XY plane orthogonal to the imaging center axis Z. The angle of the normal vector N with respect to the axis.

  Here, when one direction of the Z axis is an inclination angle θa = 0 ° and one direction of the X axis is an azimuth angle θb = 0 °, the inclination direction of the inclined surface of the workpiece W viewed from the camera 3 is the inclination angle θa. The range of “−90 ° to 90 °” and the azimuth angle θb “0 ° to 360 °” can be arbitrarily set. However, the ranges of the inclination angle θa and the azimuth angle θb that the inclination calculation unit 41 can obtain using the rotation analyzer method are the inclination angle θa “0 ° to 90 °” and the azimuth angle θb “0 ° to 180 °”. It is. Therefore, when the inclination of the inclined surface is determined using the calculation result of the inclination calculating unit 41, there is a possibility that the difference between the inclination directions of the plurality of inclined surfaces cannot be identified.

  Therefore, the inclination correction unit 42 of the three-dimensional calculation unit 4 corrects the calculation result of the inclination calculation unit 41 to determine the correct inclination of the inclined surface, and this inclination correction will be described below.

  As the workpiece W, a workpiece W1 shown in FIGS. 3, 4A and 4B is used. The workpiece W1 has a trapezoidal shape in which end surfaces M3 and M4 facing each other in the Y-axis direction (only the end surface M3 in one end direction is shown in FIGS. 3 and 4B) are shorter in the upper base than in the lower base. Further, the side surfaces facing each other in the X-axis direction are configured by an inclined surface M1 inclined in one direction and M2 inclined in the other direction, and an inner angle formed between the inclined surfaces M1 and M2 with respect to the XY plane is , “45 °”.

  The three-dimensional calculation unit 4 needs to identify all the inclination directions that the inclined surface can take within the respective ranges of the inclination angle θa “−90 ° to 90 °” and the azimuth angle θb “0 ° to 360 °”. is there. As a method for identifying the inclination direction, by making it possible to set both the positive inclination angle θa and the negative inclination angle θa with respect to the azimuth angle θb in the range of “0 ° to 180 °”, All inclination directions can be identified. Therefore, the inclination correction unit 42 of the present embodiment determines the inclination angle θa and the azimuth angle θb within the respective ranges of the inclination angle θa: “−90 ° to 90 °” and the azimuth angle θb: “0 ° to 180 °”. It shall be.

  Further, the workpiece W1 is fixed on a pedestal main body 61 of the work pedestal 6, and the pedestal main body 61 is configured to be rotatable around an axis of a rotation shaft 62 provided in the Y-axis direction. Thus, rotation control of the pedestal main body 61 is performed. That is, the work base 6 corresponds to a posture changing unit that changes the relative angle between the imaging direction (Z axis) of the camera 3 and the surface of the work W1 by rotating the work W1.

  First, the inclination calculating unit 41 controls the rotation of the pedestal main body 61 so that the normal direction of the upper surface M5 of the workpiece W1 coincides with the Z-axis direction as shown in FIGS. 5A and 5B (first state). ) In this state, the polarization analysis is performed. That is, the inclination angle θa and the azimuth angle θb of the normal vector N of the surface piece Sn are obtained for the inclined surfaces M1 and M2 and the upper surface M5 of the workpiece W1 in the first state. Hereinafter, the inclination angle θa and the azimuth angle θb of the normal vector N of the surface piece Sn are simply referred to as the inclination angle θa and the azimuth angle θb.

  FIG. 7A shows the inclination angles θa11 and θa21 and the azimuth angles θb11 and θb21 on the inclined surfaces M1 and M2 derived by the inclination calculation unit 41 in the first state. The inclination angle θa11 (first inclination angle) on the inclined surface M1 is “45 °”, the azimuth angle θb11 (first azimuth angle) is “0 °”, and the inclination angle θa21 (first inclination angle) on the inclined surface M2 is set. ) Is also “45 °”, and the azimuth angle θb21 (first azimuth angle) is also “0 °”. That is, the normal vectors N1 and N2 of the inclined surfaces M1 and M2 are the same as the normal vectors N1 and N2a in FIGS. 5A and 5B, though they are actually formed in different directions. The analysis result is as if it is formed in the direction.

  Next, the inclination calculating unit 41 controls the rotation of the pedestal main body 61 to rotate the workpiece W1 about the Y axis by the rotation angle θy = 5 ° (counterclockwise) as shown in FIGS. 6 (a) and 6 (b). (Second state), the relative angle between the imaging direction (Z-axis) of the camera 3 and the surface of the workpiece W1 is changed. Then, the polarization analysis is performed in this state. It is desirable that the rotation angle θy is larger than the measurement accuracy of the inclination angle θa and is as small as possible.

  FIG. 7B shows the inclination angles θa12 and θa22 and the azimuth angles θb12 and θb22 on the inclined surfaces M1 and M2 derived by the inclination calculation unit 41 in the second state. The inclination angle θa12 (second inclination angle) on the inclined surface M1 is “40 °”, the azimuth angle θb12 (second azimuth angle) is “0 °”, and the inclination angle θa22 (second inclination angle) on the inclined surface M2 is set. ) Is “50 °”, and the azimuth angle θb22 (second azimuth angle) is “0 °”.

  Then, the inclination correcting unit 42 determines the inclination angle θa based on the difference between the inclination angle θa before the rotation of the workpiece W1 (first state) and the inclination angle θa after the rotation of the workpiece W1 (second state). FIG. 7C shows the correction result.

  Specifically, in the inclined surface M1, the inclination angle θa12 is smaller than the inclination angle θa11 (θa11−θa12> 0). In this case, the sign of the inclination angle θa11 is set to be positive, and the inclination angle θa10 = θa11 = 45 ° in the inclined surface M1 is set. On the other hand, in the inclined surface M2, the inclination angle θa22 is larger than the inclination angle θa21 (θa21−θa22 <0). In this case, the sign of the inclination angle θa21 is set to be negative, and the inclination angle θa20 = −θa21 = −45 ° in the inclined surface M2 is set.

  Further, the inclination correcting unit 42 sets the azimuth angle θb10 = θb11 = 0 ° on the inclined surface M1 and the azimuth angle θb20 = θb21 = 0 ° on the inclined surface M2.

  Thus, the inclination correction unit 42 creates the inclination angle θa10 and the azimuth angle θb10 as inclination data on the inclined plane M1, and creates the inclination angle θa20 and the azimuth angle θb20 as inclination data on the inclined plane M2.

  The three-dimensional calculation unit 4 determines the inclination of the surface piece Sn by performing the inclination calculation process and the inclination correction process for each pixel not only on the inclined surfaces M1 and M2 but also on the upper surface M5. Therefore, by making these surface pieces Sn continuous, the measured three-dimensional shape of the workpiece W1 has an inclined surface in which the correct normal vector N is set. The relationship between the increase / decrease in the tilt angle θa due to the rotation of the workpiece W1 and the sign (positive or negative) of the tilt angle θa is derived in advance by an actual test or simulation.

  Then, the tilt correction unit 42 outputs the measurement data of the three-dimensional shape of the work W1 to the display unit 5, and the display unit 5 displays the external view and dimensions of the work W1 based on the tilt data received from the tilt correction unit 42. Are displayed as shape data.

  In this way, by changing the relative angle between the imaging direction (Z-axis) of the camera 3 and the surface of the workpiece W, the inclination angle calculated by the inclination calculation unit 41 through polarization analysis is corrected by the inclination correction unit 42. . Therefore, the measurement result of the three-dimensional shape of the workpiece W1 can identify the difference in the inclination direction of the inclined surfaces M1 and M2, and can distinguish the inclined surfaces M1 and M2. That is, the three-dimensional measurement apparatus A1 can identify the difference between the inclination directions of the plurality of inclined surfaces using the polarization analysis.

  Even when the workpiece W2 shown in FIGS. 8A and 8B is used, the difference between the inclined directions of the inclined surface can be recognized as described above.

  The workpiece W2 is formed by continuously providing two triangular prisms, and the end faces M15 and M16 (only the end face M15 in one end direction shown in FIG. 8B) facing each other in the Y-axis direction are two triangles. It becomes the shape which arranged two. And it has four inclined surfaces M11-M14 formed in parallel with the Y-axis direction, the inclined surfaces M11, M12 constitute one vertex of the triangle, and the inclined surfaces M13, M14 are one vertex of the triangle. Is configured. Further, the inclined surfaces M11, M13 are inclined in the same direction, the inclined surfaces M12, M14 are inclined in the same direction, and the inclined surfaces M11, M13 and the inclined surfaces M12, M14 are inclined in different directions, The internal angle formed between the inclined surfaces M11 to M14 and the XY plane is “30 °”.

  And the inclination calculation part 41 controls rotation of the base main body 61, and makes the normal direction of the bottom face of the workpiece | work W2 correspond to a Z-axis direction, as shown to Fig.8 (a) (b) (1st state). In this state, the polarization analysis is performed. That is, the inclination angle θa and the azimuth angle θb of the surface piece Sn are obtained for the inclined surfaces M11 to M14 of the workpiece W2 in the first state.

  FIG. 10A shows the inclination angles θa111, θa121, θa131, θa141 and the azimuth angles θb111, θb121, θb131, θb141 in the inclined surfaces M11 to M14 derived by the inclination calculation unit 41 in the first state. The inclination angles θa111 to θa141 (first inclination angles) on the inclined surfaces M11 to M14 are “30 °”, and the azimuth angles θb111 to θb141 (first azimuth angles) are “0 °”. That is, although the normal vectors N11 and N13 of the inclined surfaces M11 and M13 and the normal vectors N12 and N14 of the inclined surfaces M12 and M14 are actually formed in different directions, FIG. The analysis results are as if they were formed in the same direction as the normal vectors N11a, N12, N13a, and N14 in (b).

  Next, the inclination calculating unit 41 controls the rotation of the pedestal main body 61 to rotate the workpiece W2 about the Y axis by a rotation angle θy = 5 ° (counterclockwise) as shown in FIGS. 9 (a) and 9 (b). (Second state), the relative angle between the imaging direction (Z-axis) of the camera 3 and the surface of the workpiece W2 is changed. Then, the polarization analysis is performed in this state. That is, regarding the inclined surfaces M11 to M14 of the workpiece W2 in the second state, the inclination angle θa and the azimuth angle θb of the surface piece Sn are obtained, respectively.

  FIG. 10B shows the inclination angle θa and the azimuth angle θb in the inclined surfaces M11 to M14 derived by the inclination calculation unit 41 in the second state. The inclination angles θa112 and θa132 (second inclination angle) on the inclined surfaces M11 and M13 are “35 °”, and the azimuth angles θb112 and θb132 (second azimuth angle) are “0 °”. Further, the inclination angles θa122 and θa142 (second inclination angle) on the inclined surfaces M12 and M14 are “25 °”, and the azimuth angles θb122 and θb142 (second azimuth angle) are “0 °”.

  Then, the inclination correction unit 42 determines the inclination angle θa based on the difference between the inclination angle θa before the rotation of the workpiece W2 (first state) and the inclination angle θa after the rotation of the workpiece W2 (second state). FIG. 10C shows the correction result.

  Specifically, in the inclined surface M11, the inclination angle θa112 is larger than the inclination angle θa111 (θa111−θa112 <0). In this case, the sign of the inclination angle θa111 is set to be negative, and the inclination angle θa110 = −θa111 = −30 ° in the inclined surface M11 is set. Similarly, since the inclination angle θa132 of the inclined surface M13 is larger than the inclination angle θa131 (θa131−θa132 <0), the sign of the inclination angle θa131 is set to be negative, and the inclination angle θa130 = −θa131 = -30 °.

  In the inclined surface M12, the inclination angle θa122 is smaller than the inclination angle θa121 (θa121−θa122> 0). In this case, the sign of the inclination angle θa121 is set to be positive, and the inclination angle θa120 = θa121 = 30 ° in the inclined surface M12 is set. Similarly, since the tilt angle θa142 is smaller than the tilt angle θa141 (θa141−θa142> 0), the sign of the tilt angle θa141 is set to be positive, and the tilt angle θa140 = θa141 = 30 on the tilted surface M14. °.

  Further, the inclination correction unit 42 has an azimuth angle θb110 = θb111 = 0 ° on the inclined surface M11, an azimuth angle θb120 = θb121 = 0 ° on the inclined surface M12, an azimuth angle θb130 = θb131 = 0 ° on the inclined surface M13, and the inclined surface M14. At azimuth angle θb140 = θb141 = 0 °.

  Thus, the tilt correction unit 42 creates the tilt angle θa110 and the azimuth angle θb110 as the tilt data on the tilted surface M11, and creates the tilt angle θa120 and the azimuth angle θb120 as the tilt data on the tilted surface M12. Furthermore, the inclination correction unit 42 creates the inclination angle θa130 and the azimuth angle θb130 as inclination data on the inclined plane M13, and creates the inclination angle θa140 and the azimuth angle θb140 as inclination data on the inclined plane M14.

  The three-dimensional calculation unit 4 determines the inclination of the surface piece Sn by performing the inclination calculation process and the inclination correction process for each pixel. Therefore, by making these surface pieces Sn continuous, the measured three-dimensional shape of the workpiece W2 has an inclined surface in which the correct normal vector N is set. The relationship between the increase / decrease in the tilt angle θa due to the rotation of the workpiece W2 and the sign (positive or negative) of the tilt angle θa is derived in advance by an actual test or simulation.

  Then, the tilt correction unit 42 outputs the measurement data of the three-dimensional shape of the workpiece W2 to the display unit 5, and the display unit 5 displays the external view and dimensions of the workpiece W2 based on the tilt data received from the tilt correction unit 42. Are displayed as shape data.

(Embodiment 2)
The three-dimensional measurement apparatus A1 of the present embodiment is different from the first embodiment in the inclination correction processing by the inclination correction unit 42 of the three-dimensional calculation unit 4, and the same components as those in the first embodiment are denoted by the same reference numerals. Description is omitted.

  The three-dimensional calculation unit 4 needs to identify all inclination directions that the inclined surface can take within the respective ranges of the inclination angle θa “−90 ° to 90 °” and the azimuth angle θb “0 ° to 360 °”. As a method for identifying the inclination direction, the inclination angle θa in the range of “0 ° to 90 °” can be set over the entire circumference (0 ° to 360 °) of the azimuth angle θb. Can be identified. Therefore, the inclination correction unit 42 of this embodiment determines the inclination angle θa and the azimuth angle θb within the respective ranges of the inclination angle θa: “0 ° to 90 °” and the azimuth angle θb: “0 ° to 360 °”. Shall.

  First, the inclination calculating unit 41 controls the rotation of the pedestal main body 61 so that the normal direction of the upper surface M5 of the workpiece W1 coincides with the Z-axis direction as shown in FIGS. 5A and 5B (first state). ) In this state, the polarization analysis is performed. That is, the inclination angle θa and the azimuth angle θb of the surface piece Sn are obtained for the inclined surfaces M1 and M2 and the upper surface M5 of the workpiece W1 in the first state. FIG. 11A shows the inclination angles θa11 and θa21 and the azimuth angles θb11 and θb21 of the surface pieces Sn of the inclined surfaces M1 and M2 derived by the inclination calculation unit 41 in the first state. Note that the derivation result shown in FIG. 11A is the same as that in FIG.

  Next, the inclination calculating unit 41 controls the rotation of the pedestal main body 61 to rotate the workpiece W1 about the Y axis by the rotation angle θy = 5 ° (counterclockwise) as shown in FIGS. 6 (a) and 6 (b). (Second state), the relative angle between the imaging direction (Z-axis) of the camera 3 and the surface of the workpiece W1 is changed. Then, the polarization analysis is performed in this state. FIG. 11B shows the inclination angles θa12 and θa22 and the azimuth angles θb12 and θb22 of the surface pieces Sn of the inclined surfaces M1 and M2 derived by the inclination calculation unit 41 in the second state. Note that the derivation result shown in FIG. 11B is the same as that in FIG. 7B, and a description thereof will be omitted.

  Then, the inclination correcting unit 42 sets the azimuth angle θb based on the difference between the inclination angle θa before the rotation of the workpiece W1 (first state) and the inclination angle θa after the rotation of the workpiece W1 (second state). FIG. 11C shows the correction result.

  Specifically, in the inclined surface M1, the inclination angle θa12 is smaller than the inclination angle θa11 (θa11−θa12> 0). In this case, the azimuth angle θb11 is not corrected, and the azimuth angle θb10 = θb11 = 0 ° on the inclined surface M1. On the other hand, in the inclined surface M2, the inclination angle θa22 is larger than the inclination angle θa21 (θa21−θa22 <0). In this case, 180 ° is added to the azimuth angle θb21, and the azimuth angle θb20 = θb21 + 180 ° = 180 ° in the inclined surface M2.

  Further, the inclination correction unit 42 sets the inclination angle θa10 = θa11 = 45 ° on the inclined surface M1 and the inclination angle θa20 = θa21 = 45 ° on the inclined surface M2.

  Thus, the inclination correction unit 42 creates the inclination angle θa10 and the azimuth angle θb10 as inclination data on the inclined plane M1, and creates the inclination angle θa20 and the azimuth angle θb20 as inclination data on the inclined plane M2.

  The three-dimensional calculation unit 4 determines the inclination of the surface piece Sn by performing the inclination calculation process and the inclination correction process for each pixel not only on the inclined surfaces M1 and M2 but also on the upper surface M5. Therefore, by making these surface pieces Sn continuous, the measured three-dimensional shape of the workpiece W1 has an inclined surface in which the correct normal vector N is set. The relationship between the increase / decrease in the tilt angle θa due to the rotation of the workpiece W1 and the correction amount (0 ° or + 180 °) of the azimuth angle θb is derived in advance by an actual test or simulation.

  Then, the tilt correction unit 42 outputs the measurement data of the three-dimensional shape of the work W1 to the display unit 5, and the display unit 5 displays the external view and dimensions of the work W1 based on the tilt data received from the tilt correction unit 42. Are displayed as shape data.

  Thus, by changing the relative angle between the imaging direction (Z-axis) of the camera 3 and the surface of the workpiece W, the azimuth angle calculated by the tilt calculation unit 41 by the polarization analysis is corrected by the tilt correction unit 42. . Therefore, the measurement result of the three-dimensional shape of the workpiece W1 can identify the difference in the inclination direction of the inclined surfaces M1 and M2, and can distinguish the inclined surfaces M1 and M2. That is, the three-dimensional measurement apparatus A1 can identify the difference between the inclination directions of the plurality of inclined surfaces using the polarization analysis.

  Even when the workpiece W2 shown in FIGS. 8A and 8B is used, the difference between the inclined directions of the inclined surface can be recognized as described above.

  First, the inclination calculating unit 41 controls the rotation of the pedestal main body 61 so that the normal direction of the bottom surface of the workpiece W2 coincides with the Z-axis direction as shown in FIGS. 8A and 8B (first state). In this state, the polarization analysis is performed. That is, the inclination angle θa and the azimuth angle θb of the surface piece Sn are obtained for the inclined surfaces M11 to M14 of the workpiece W2 in the first state. FIG. 12A shows the inclination angles θa111, θa121, θa131, θa141, and azimuth angles θb111, θb121, θb131, and the surface pieces Sn of the inclined surfaces M11 to M14 derived by the inclination calculation unit 41 in the first state. θb141 is shown. Note that the derivation result shown in FIG. 12A is the same as that in FIG.

  Next, the inclination calculating unit 41 controls the rotation of the pedestal main body 61 to rotate the workpiece W2 about the Y axis by a rotation angle θy = 5 ° (counterclockwise) as shown in FIGS. 9 (a) and 9 (b). (Second state), the relative angle between the imaging direction (Z-axis) of the camera 3 and the surface of the workpiece W2 is changed. Then, the polarization analysis is performed in this state. That is, regarding the inclined surfaces M11 to M14 of the workpiece W2 in the second state, the inclination angle θa and the azimuth angle θb of the surface piece Sn are obtained, respectively. FIG. 12B shows the inclination angles θa112, θa122, θa132, θa142, and azimuth angles θb112, θb122, θb132, θb142 is shown. Note that the derivation result shown in FIG. 12B is the same as that in FIG.

  Then, the inclination correction unit 42 sets the azimuth angle θb based on the difference between the inclination angle θa before the rotation of the workpiece W2 (first state) and the inclination angle θa after the rotation of the workpiece W2 (second state). FIG. 12C shows the correction result.

  Specifically, in the inclined surface M11, the inclination angle θa112 is larger than the inclination angle θa111 (θa111−θa112 <0). In this case, 180 ° is added to the azimuth angle θb111, and the azimuth angle θb110 = θb111 + 180 ° = 180 ° in the inclined plane M11. Similarly, since the inclination angle θa132 of the inclined surface M13 is larger than the inclination angle θa131 (θa131−θa132 <0), 180 ° is added to the azimuth angle θb131, and the azimuth angle θb130 = θb131 + 180 ° = 180 in the inclined surface M13. °.

  In the inclined surface M12, the inclination angle θa122 is smaller than the inclination angle θa121 (θa121−θa122> 0). In this case, the azimuth angle θb121 is not corrected, and the azimuth angle θb120 = θb121 = 0 ° in the inclined surface M12 is set. Similarly, in the inclined surface M14, since the inclination angle θa142 is smaller than the inclination angle θa141 (θa141-θa142> 0), the azimuth angle θb141 is not corrected, and the azimuth angle θb140 = θb141 = 0 ° in the inclined surface M14. .

  In addition, the inclination correcting unit 42 has an inclination angle θa110 = θa111 = 30 ° on the inclined surface M11, an inclination angle θa120 = θa121 = 30 ° on the inclined surface M12, an inclination angle θa130 = θa131 = 30 ° on the inclined surface M13, and an inclined surface M14. Inclination angle θa140 = θa141 = 30 °.

  Thus, the tilt correction unit 42 creates the tilt angle θa110 and the azimuth angle θb110 as the tilt data on the tilted surface M11, and creates the tilt angle θa120 and the azimuth angle θb120 as the tilt data on the tilted surface M12. Furthermore, the inclination correction unit 42 creates the inclination angle θa130 and the azimuth angle θb130 as inclination data on the inclined plane M13, and creates the inclination angle θa140 and the azimuth angle θb140 as inclination data on the inclined plane M14.

  The three-dimensional calculation unit 4 determines the inclination of the surface piece Sn by performing the inclination calculation process and the inclination correction process for each pixel. Therefore, by making these surface pieces Sn continuous, the measured three-dimensional shape of the workpiece W2 has an inclined surface in which the correct normal vector N is set. The relationship between the increase / decrease in the tilt angle θa due to the rotation of the workpiece W2 and the correction amount (0 ° or + 180 °) of the azimuth angle θb is derived in advance by an actual test or simulation.

  Then, the tilt correction unit 42 outputs the measurement data of the three-dimensional shape of the workpiece W2 to the display unit 5, and the display unit 5 displays the external view and dimensions of the workpiece W2 based on the tilt data received from the tilt correction unit 42. Are displayed as shape data.

(Embodiment 3)
FIG. 13 shows the configuration of the three-dimensional measurement apparatus A2 of this embodiment. The three-dimensional measurement apparatus A2 includes an illumination unit 1, a linearly polarizing plate 2, a camera 3 (imaging device), a three-dimensional calculation unit 4, and the like. The display unit 5 and the camera pedestal 7 (posture changing means). In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1, 2, and description is abbreviate | omitted.

  The camera 3 is fixed on a pedestal main body 71 of the camera pedestal 7, and the pedestal main body 71 is configured to be rotatable around the rotation axis 72 provided in the Y-axis direction. The rotation control of the pedestal main body 71 is performed. That is, the camera pedestal 7 corresponds to posture changing means for changing the relative angle between the imaging direction (Z axis) of the camera 3 and the surface of the workpiece W by rotating the camera 3.

  Since the camera base 7 can change the relative angle between the imaging direction of the camera 3 and the surface of the workpiece W, the tilt by the tilt correction unit 42 of the three-dimensional calculation unit 4 is the same as in the first and second embodiments. Correction processing can be performed.

  Therefore, the measurement result of the three-dimensional shape of the workpiece W can identify the difference in the inclination direction of the inclined surface as in the first and second embodiments, and can distinguish the inclined surface. In other words, the three-dimensional measuring apparatus A2 can identify the difference in the inclination directions of the plurality of inclined surfaces while using the polarization analysis.

A1 3D measuring device 1 Illumination unit 2 Linear polarizing plate 3 Camera (imaging device)
4 Three-dimensional calculation part 41 Inclination calculation part 42 Inclination correction part 5 Display part 6 Work base (attitude change means)
W Workpiece (object to be measured)

Claims (6)

From bowl-shaped irradiation surface of a hemisphere, a lighting device for morphism the first light to the surface of the circular polarization of the object to be measured which is located approximately at the center of an opening of the irradiated surface irradiation,
An imaging device for generating imaging data obtained by imaging the second light formed by reflecting the first light on the surface of the measurement object;
Posture changing means for changing a relative angle between the imaging direction of the imaging device and the surface of the object to be measured;
Based on the imaging data generated by the imaging device with the relative angle set to the first state by the posture changing means, the azimuth angle and elliptical angle of the polarization ellipse as the polarization state of the elliptically polarized light of the second light And detecting a first tilt angle and a first azimuth angle of the surface of the object to be measured based on the detected polarization state, and changing the relative angle from the first state by the posture changing means. Based on the imaging data generated by the imaging device after being changed to the second state, the azimuth angle and ellipticity ratio of the polarization ellipse are detected as the polarization state of the elliptically polarized light of the second light, and this detection is performed. Based on the polarization state, the second tilt angle and the second azimuth angle of the surface of the object to be measured are obtained, and based on the difference between the first tilt angle and the second tilt angle, the first tilt angle is calculated. A three-dimensional calculation unit that corrects the tilt angle of Prepared ,
The three-dimensional calculation unit corrects the first inclination angle by determining a positive or negative sign of the first inclination angle according to a difference between the first inclination angle and the second inclination angle. A three-dimensional measuring apparatus characterized by: An illumination device that irradiates a circularly polarized first light from a hemispherical bowl-shaped irradiation surface to a surface of an object to be measured disposed substantially at the center of the opening of the irradiation surface;
An imaging device for generating imaging data obtained by imaging the second light formed by reflecting the first light on the surface of the measurement object;
Posture changing means for changing a relative angle between the imaging direction of the imaging device and the surface of the object to be measured;
Based on the imaging data generated by the imaging device with the relative angle set to the first state by the posture changing means, the azimuth angle and elliptical angle of the polarization ellipse as the polarization state of the elliptically polarized light of the second light And detecting a first tilt angle and a first azimuth angle of the surface of the object to be measured based on the detected polarization state, and changing the relative angle from the first state by the posture changing means. Based on the imaging data generated by the imaging device after being changed to the second state, the azimuth angle and ellipticity ratio of the polarization ellipse are detected as the polarization state of the elliptically polarized light of the second light, and this detection is performed. Based on the polarization state, the second tilt angle and the second azimuth angle of the surface of the object to be measured are obtained, and based on the difference between the first tilt angle and the second tilt angle, the first tilt angle is calculated. A three-dimensional calculation unit for correcting the azimuth angle of
With
The three-dimensional calculation unit corrects the first azimuth angle by shifting the first azimuth angle by 180 degrees according to a difference between the first tilt angle and the second tilt angle.
A three-dimensional measuring apparatus characterized by that. The orientation change means, said by rotating the measurement object, three-dimensional claim 1 or 2, wherein changing the relative angle between the surface of the imaging direction said object to be measured of the imaging device Measuring device. 3. The three-dimensional measurement according to claim 1, wherein the posture changing unit changes a relative angle between an imaging direction of the imaging device and a surface of the measurement object by rotating the imaging device. apparatus. The circularly polarized first light is irradiated from the hemispherical bowl-shaped irradiation surface to the surface of the object to be measured disposed at the approximate center of the opening of the irradiation surface, and the first light is reflected by the surface of the object to be measured. Imaging data obtained by imaging the second light formed in this manner is generated, a polarization state of the second light is detected based on the imaging data, and the object to be measured is detected based on the detected polarization state. In the three-dimensional measurement method for obtaining the tilt angle and azimuth angle of the surface of
Based on the imaging data generated by setting the relative angle between the imaging direction for imaging the second light and the surface of the object to be measured to the first state, the polarization state of the elliptically polarized light of the second light Detecting the azimuth angle and the ellipticity ratio of the polarization ellipse, and determining the first tilt angle and the first azimuth angle of the surface of the object to be measured based on the detected polarization state;
Based on the imaging data generated after the relative angle is changed from the first state to the second state, the azimuth angle and ellipticity rate of the polarization ellipse are obtained as the polarization state of the elliptically polarized light of the second light. Detecting and determining a second tilt angle and a second azimuth angle of the surface of the object to be measured based on the detected polarization state;
Correcting the first tilt angle by determining a sign of the first tilt angle according to a difference between the first tilt angle and the second tilt angle;
A three-dimensional measurement method comprising: From bowl-shaped irradiation surface of a hemisphere, said shines the first light to the surface of the circular polarization of the object to be measured which is located approximately at the center of an opening of the irradiated surface irradiation, the first light at the surface of the object to be measured Imaging data obtained by imaging the second light formed by reflection is generated, a polarization state of the second light is detected based on the imaging data, and the measurement target is based on the detected polarization state. In the three-dimensional measurement method for obtaining the tilt angle and azimuth angle of the surface of an object,
Based on the imaging data generated by setting the relative angle between the imaging direction for imaging the second light and the surface of the object to be measured to the first state, the polarization state of the elliptically polarized light of the second light Detecting the azimuth angle and the ellipticity ratio of the polarization ellipse , and determining the first tilt angle and the first azimuth angle of the surface of the object to be measured based on the detected polarization state;
Based on the imaging data generated after the relative angle is changed from the first state to the second state, the azimuth angle and ellipticity rate of the polarization ellipse are obtained as the polarization state of the elliptically polarized light of the second light. Detecting and determining a second tilt angle and a second azimuth angle of the surface of the object to be measured based on the detected polarization state;
Correcting the first azimuth angle by shifting the first azimuth angle by 180 ° in accordance with a difference between the first tilt angle and the second tilt angle. 3D measurement method.

Images