JP6075352B2 - Pattern irradiation apparatus and system - Google Patents

Description

  The present invention relates to a pattern irradiation apparatus and system.

  Conventionally, a system for handling an object (work) loaded on a tray using a robot and transporting the object to an apparatus in the next process or assembling a product using the object is known. Yes. In such a system, the distance of the object on the tray is measured by a three-dimensional measuring device, and the position and orientation of the object are recognized based on the measurement result for handling. Moreover, in such a system, the pattern irradiation apparatus irradiates the object on the tray with a random pattern of light to improve the accuracy of distance measurement by the three-dimensional measurement apparatus (for example, Patent Document 1).

  By the way, the pattern irradiation apparatus had to change the pattern irradiated to the object according to the shape, size, surface gloss, etc. of the object loaded on the tray. For this reason, the pattern irradiation apparatus has to include a mechanism for changing the random pattern, a control unit, and the like, resulting in a complicated configuration.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a pattern irradiation apparatus and system capable of displaying a versatile random pattern that can be applied to various cases with a simple configuration. To do.

To solve the above problems and achieve the object, the pattern irradiation device according to the present invention includes a light emitting portion for emitting coherent light, the light by the light emitting portion is incident, transmits or reflects incident light The first plate, the light transmitted or reflected by the first plate is incident, the second plate transmitting or reflecting the incident light, and the light transmitted or reflected by the second plate are incident and incident And an irradiation optical system for magnifying the irradiated light to irradiate the projection surface, wherein the first plate has irregularities with a pitch smaller than the incident light spot, and the first pattern with a random luminance distribution is formed on the first plate. A random mask pattern is drawn on the second plate, and a second pattern having a random luminance distribution with a spatial frequency different from that of the first pattern is displayed on the projection plane.

  According to the present invention, it is possible to display a highly versatile pattern that can handle various cases with a simple configuration.

FIG. 1 is a diagram showing a handling system according to the first embodiment. FIG. 2 is a diagram illustrating a configuration of the pattern irradiation apparatus according to the first embodiment. FIG. 3 is a perspective view of a part of the pattern irradiation apparatus according to the first embodiment. FIG. 4 is a diagram schematically showing the arrangement of the transmission diffusion plate, the image forming unit, and the irradiation optical system. FIG. 5 is a diagram illustrating an example of the first pattern. FIG. 6 is a diagram illustrating an example of the second pattern. FIG. 7 is a diagram illustrating an example of a pattern obtained by combining the first pattern and the second pattern. FIG. 8 is a diagram illustrating a configuration of a pattern irradiation apparatus according to the second embodiment. FIG. 9 is a diagram illustrating a configuration of a pattern irradiation apparatus according to the third embodiment. FIG. 10 is a diagram illustrating an example of a light emission pattern by the light emitting unit according to the third embodiment.

  Hereinafter, a handling system 10 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a diagram showing a handling system 10 according to the first embodiment. The handling system 10 handles the object 11 (work), transports the object 11 to the next process apparatus, and assembles a product using the object 11.

  The handling system 10 includes a tray 12, a robot 13, a pattern irradiation device 20, a three-dimensional measurement device 21, a recognition device 22, and a robot controller 23. The tray 12 is loaded with at least one object 11.

  The robot 13 handles any object 11 loaded on the tray 12 by moving the arm, and moves the handled object 11 to a specified position or holds it in a specified posture. The robot 13 may handle the object 11 by opening and closing the claws, may handle the object 11 by air adsorption, or may handle the object 11 by electromagnetic force.

  The pattern irradiation device 20 irradiates the tray 12 on which the object 11 is loaded with a single-color random pattern image. As a result, the exposed pattern on the surface of each object 11 loaded on the tray 12 is irradiated with a random pattern. In the present embodiment, the pattern irradiation device 20 emits blue light, but is not limited to blue, and may be any color or white.

  The three-dimensional measuring device 21 measures the distance to each position on the exposed surface of each object 11 loaded on the tray 12 in a state where light of a random pattern is irradiated by the pattern irradiation device 20. As an example, the three-dimensional measuring device 21 measures the distance with a stereo camera or the like, and generates three-dimensional information representing the distance to each position on the surface of the subject.

  The recognition device 22 recognizes the position and orientation of each object 11 based on the distance to the surface position of each object 11 measured by the three-dimensional measurement device 21. As an example, the recognition device 22 executes matching processing such as matching processing with a three-dimensional model or surface matching processing to recognize the position and orientation of each object 11. Furthermore, the recognition device 22 may complement the matching process by performing edge extraction or the like based on the luminance information.

  The robot controller 23 controls the operation of the robot 13 based on the position and orientation of each object 11 recognized by the recognition device 22 in accordance with a control flow registered in advance. Then, the robot controller 23 handles the designated object 11 on the tray 12.

  In such a handling system 10, the pattern irradiation device 20 irradiates each object 11 loaded on the tray 12 with light of a random pattern that improves the accuracy of the three-dimensional measurement by the three-dimensional measurement device 21. To do. Thereby, according to the handling system 10, the position and attitude | position of each target object 11 loaded on the tray 12 can be recognized accurately, and the target object 11 can be handled with high precision.

  FIG. 2 is a diagram illustrating a configuration of the pattern irradiation apparatus 20 according to the first embodiment. The pattern irradiation device 20 irradiates the projection surface 30 with a random pattern image that improves the accuracy of distance measurement by the three-dimensional measurement device 21. The projection surface 30 corresponds to the tray 12 on which the object 11 is loaded in the handling system 10.

  The pattern irradiation apparatus 20 includes a light emitting unit 31, a light collecting unit 32, a transmission diffusion plate 33 (first plate), a light tunnel 34, an image forming unit 35 (second plate), and an irradiation optical system 36. Prepare.

  In the figure, x, y, and z indicate directions orthogonal to each other. The x direction represents a direction parallel to the optical axis of the light tunnel 34. The y direction represents a direction orthogonal to the x direction. The z direction represents a direction orthogonal to the x direction and the y direction.

  The light emitting unit 31 emits light. In the present embodiment, the light emitting unit 31 emits a plurality of parallel light beams in the same direction.

  The light emitting unit 31 includes a plurality of laser diodes 41 that are light sources and a plurality of collimator lenses 42. The plurality of laser diodes 41 emit laser light that is coherent light in the same direction. In the present embodiment, each laser diode 41 is a blue laser diode that emits blue laser light having a wavelength of 440 nm to 500 nm, for example. Each laser diode 41 is not limited to blue, but may be other colors. Further, the laser diode 41 may emit laser light other than visible light as long as the light irradiated by the three-dimensional measuring device 21 can be detected.

  The plurality of collimator lenses 42 are provided in a one-to-one correspondence with each of the plurality of laser diodes 41. Each collimator lens 42 receives the laser beam emitted from the corresponding laser diode 41 and emits it as a parallel light beam. Thereby, the light emission part 31 can radiate | emit the laser beam of the several parallel light beam in the same direction.

  The condensing unit 32 condenses the light emitted from the light emitting unit 31 on the transmission diffusion plate 33. In the present embodiment, the condensing unit 32 is a lens, and condenses a plurality of laser beams at approximately one point on the transmission diffusion plate 33.

  The transmission diffusion plate 33 is a diffusion unit that diffuses incident light. The transmission diffusion plate 33 is entirely flat and has fine and random irregularities formed on at least one plane. The transmissive diffusion plate 33 receives a plurality of laser beams collected by the condensing unit 32 and emits the incident light to the light tunnel 34 while diffusing the incident light. For example, the transmission diffusion plate 33 diffuses light at a diffusion angle of 5 ° to 10 ° of the full width at half maximum.

  The light tunnel 34 is a homogenizing optical system that uniformizes the luminance distribution on a plane (y direction and z direction) perpendicular to the optical axis direction (x direction) of light passing therethrough. The light tunnel 34 has a cylindrical shape, and a reflection surface that reflects light inward is formed inside the cylinder. The light tunnel 34 functions as an optical path through which light passes through the inside of the cylinder. Such a light tunnel 34 receives the light diffused by the transmissive diffusion plate 33, passes the incident light while reflecting it internally, and emits the light with a uniform luminance distribution. The inside of the light tunnel 34 may be hollow or may be filled with a transparent member such as glass as long as light can pass therethrough.

  The light emitted from the light tunnel 34 enters the image forming unit 35. For example, the image forming unit 35 is a transparent plate such as glass, and is a photomask on which a random mask pattern is drawn. Further, the image forming unit 35 may be a plate-like transmissive liquid crystal element that can draw a mask pattern by an electric signal. The image forming unit 35 transmits and blocks (or reflects) light according to the drawn mask pattern, and forms an image according to the mask pattern on a surface perpendicular to the optical axis. The light transmitted through the image forming unit 35 is incident on the irradiation optical system 36.

  The light that has passed through the image forming unit 35 enters the irradiation optical system 36. The irradiation optical system 36 irradiates the projection plane 30 with the incident light enlarged to a specified magnification.

  FIG. 3 is a perspective view of a part of the pattern irradiation apparatus 20 according to the first embodiment. As an example, the light emitting unit 31 includes eight laser diodes 41 arranged in a 2 × 4 matrix. Further, the light emitting unit 31 includes eight collimator lenses 42 provided corresponding to the respective laser diodes 41. Such a light emitting unit 31 can emit eight parallel light beams in the same direction.

  Thus, since the light emission part 31 has the several laser diode 41, the energy of the light to output can be enlarged. Note that the number and arrangement of the laser diodes 41 included in the light emitting unit 31 may be any number and arrangement as long as laser light can be emitted in the same direction.

  The condensing unit 32 condenses a plurality of laser beams emitted from the light emitting unit 31 on the transmission diffusion plate 33. Therefore, even if the number of laser diodes 41 included in the light emitting unit 31 is increased, the light emitted from the laser diode 41 can be incident on the light tunnel 34 without leakage. Therefore, the pattern irradiation apparatus 20 can easily increase the energy to be output.

  FIG. 4 is a diagram schematically showing the arrangement of the transmissive diffusion plate 33, the image forming unit 35, and the irradiation optical system 36. FIG. 5 is a diagram illustrating an example of the first pattern. FIG. 6 is a diagram illustrating an example of the second pattern. FIG. 7 is a diagram illustrating an example of a pattern obtained by combining the first pattern and the second pattern.

  Coherent light emitted from the light emitting unit 31 is incident on the transmission diffusion plate 33 (first plate). The transmission diffusion plate 33 is formed with unevenness with a pitch smaller than the incident light spot. Thereby, the transmission diffusion plate 33 can diffuse and emit the incident light. When the light emitted from the transmissive diffusion plate 33 is irradiated onto the projection surface 30, a first pattern (speckle pattern) having a random luminance distribution as shown in FIG. 5 is formed on the projection surface 30. The That is, the transmission diffusion plate 33 displays a first pattern with a random luminance distribution on the projection plane 30.

  For example, the wavelength of the laser light emitted from the light emitting unit 31 is λ, the beam diameter passing through the objective lens 45 of the irradiation optical system 36 is L, and the optical path length from the objective lens 45 of the irradiation optical system 36 to the projection plane 30 is z. In this case, the order of the size of each pattern included in the first pattern is expressed by the following formula (1).

  Order of size of individual patterns included in the first pattern≈ (λ × z) / L (1)

  For example, when λ = 500 nm, z = 1 m, and L = 30 mm, the order of the size of each pattern included in the first pattern is about 17 μm from Equation (1). For example, the distance to the camera is 1 m, the focal length of the camera is 6 mm, the size of the image sensor is 1/3 inch, and the pixel pitch of the image sensor is 3.75 μm. The size of each pattern in an image obtained by capturing the first pattern with such a camera is 1 pixel or less. Thus, the transmission diffusion plate 33 can display a very fine random pattern on the projection surface 30.

  The image forming unit 35 (second plate) is, for example, a plate-like photomask or a transmissive liquid crystal element. In the image forming unit 35, a random mask pattern is drawn on a surface through which light passes with a material that blocks (or reflects) light. Such an image forming unit 35 transmits and blocks (or reflects) incident light according to a mask pattern, and forms an image according to the mask pattern on a surface perpendicular to the optical axis. As a result, when the light emitted from the image forming unit 35 is irradiated onto the projection surface 30, a second pattern having a random luminance distribution as shown in FIG. 6 is formed on the projection surface 30. That is, the image forming unit 35 displays a second pattern with a random luminance distribution on the projection surface 30.

  For example, when the minimum pattern size among the individual patterns included in the mask pattern drawn on the image forming unit 35 is M and the magnification of the irradiation optical system 36 is β, the size of the minimum pattern included in the second pattern This is represented by the following formula (2).

  Size of the minimum pattern included in the second pattern = M × β (2)

  For example, when M = 100 μm and β = 50, the size of each pattern included in the second pattern is 5 mm or more from Expression (2). For example, the distance to the camera is 1 m, the focal length of the camera is 6 mm, the size of the image sensor is 1/3 inch, and the pixel pitch of the image sensor is 3.75 μm. Each pattern in an image obtained by capturing the second pattern with such a camera is 8 pixels or more. As described above, the image forming unit 35 can display a relatively large random pattern on the projection surface 30.

  The light emitted from the transmissive diffusion plate 33 (first plate) is incident on the image forming unit 35 (second plate). Accordingly, the light emitted from the transmissive diffusion plate 33 passes through the image forming unit 35 and is irradiated onto the projection surface 30. Accordingly, a random luminance distribution pattern obtained by synthesizing the first pattern and the second pattern as shown in FIG. 7 is displayed on the projection plane 30.

  Here, the image forming unit 35 causes the projection surface 30 to display a second pattern having a random luminance distribution with a spatial frequency different from that of the first pattern. That is, a mask pattern in which the minimum pattern size M satisfies the following expression (3) is drawn on the image forming unit 35.

  M ≠ (λ × z) / (L × β) (3)

  In the present embodiment, the image forming unit 35 causes the projection surface 30 to display a second pattern including a pattern having a size larger than the pattern included in the first pattern. That is, in the present embodiment, a mask pattern is drawn on the image forming unit 35 such that the minimum pattern size M among the plurality of included patterns satisfies the following expression (4).

  M> (λ × z) / (L × β) (4)

  Thereby, the pattern irradiation apparatus 20 can display on the projection surface 30 a random pattern in which a fine pattern formed by the transmission diffusion plate 33 and a relatively large pattern formed by the image forming unit 35 are overlapped. For example, if a fine random pattern is formed by a photomask, the production cost becomes very high. On the other hand, the diffusion plate cannot generate a relatively large random pattern. Therefore, the pattern irradiation apparatus 20 displays a random pattern including a fine pattern and a relatively large pattern on the projection plane 30 with a simple configuration by combining the transmission diffusion plate 33 and the image forming unit 35. Can do.

  Further, when such a pattern irradiation device 20 is used in the handling system 10, since a random pattern with a wide spatial frequency is displayed, even if the size and shape of the object 11 change, the image forming unit 35 There is no need to switch the mask pattern being drawn. Therefore, the pattern irradiation apparatus 20 does not have to include a mechanism and a control unit for switching the mask pattern drawn on the image forming unit 35.

  Thus, according to the pattern irradiation apparatus 20 which concerns on this embodiment, a highly versatile random pattern which can respond to various cases can be displayed with a simple configuration.

(Second Embodiment)
Next, a pattern irradiation apparatus 50 according to the second embodiment will be described. The pattern irradiation apparatus 50 according to the second embodiment is applied to the handling system 10 instead of the pattern irradiation apparatus 20 according to the first embodiment. The same applies to the third embodiment.

  Further, the pattern irradiation apparatus 50 according to the second embodiment has substantially the same function and configuration as the pattern irradiation apparatus 20 according to the first embodiment. Members having substantially the same function and configuration are denoted by the same reference numerals, and detailed description thereof is omitted except for differences.

  FIG. 8 is a diagram illustrating a configuration of the pattern irradiation apparatus 50 according to the second embodiment. The pattern irradiation apparatus 50 includes a light emitting unit 31, a light collecting unit 32, a reflection diffusion plate 51 (first plate), a light tunnel 34, an image forming unit 35, and an irradiation optical system 36. The pattern irradiation device 50 is different from the first embodiment in that a reflection diffusion plate 51 is provided instead of the transmission diffusion plate 33.

  The condensing unit 32 condenses the light emitted from the light emitting unit 31 on the reflection diffusion plate 51. In the present embodiment, the condensing unit 32 condenses a plurality of laser beams at approximately one point on the reflection diffusion plate 51.

  The reflection diffusion plate 51 is a diffusion unit that diffuses incident light. The reflection diffusing plate 51 receives a plurality of laser beams condensed by the condensing unit 32 and emits the incident light to the light tunnel 34 while reflecting and diffusing the incident light. The reflection diffusion plate 51 is different from the transmission diffusion plate 33 in that light is reflected and diffused, but is the same as the transmission diffusion plate 33 in other functions and effects.

  The light tunnel 34 receives the light diffused by the reflection diffusing plate 51, and emits the light with a uniform luminance distribution.

  The reflection diffusing plate 51 has irregularities with a pitch smaller than the spot of the incident light, like the transmissive diffusing plate 33 according to the first embodiment. Thereby, the reflective diffusing plate 51 can display the first pattern having a random luminance distribution on the projection plane 30 as in the first embodiment.

(Third embodiment)
Next, a pattern irradiation apparatus 60 according to the third embodiment will be described. The pattern irradiation apparatus 60 according to the third embodiment has substantially the same function and configuration as the pattern irradiation apparatus 20 according to the first embodiment. Members having substantially the same function and configuration are denoted by the same reference numerals, and detailed description thereof is omitted except for differences.

  FIG. 9 is a diagram illustrating a configuration of a pattern irradiation apparatus 60 according to the third embodiment. The pattern irradiation device 60 includes a light emitting unit 31, a light collecting unit 32, a transmission diffusion plate 33, a light tunnel 34, an image forming unit 35, an irradiation optical system 36, and a light emission control unit 61. The pattern irradiation device 60 is different from the first embodiment in that it further includes a light emission control unit 61.

  The light emission control unit 61 selects a part of the plurality of laser diodes 41 included in the light emitting unit 31 to emit light. For example, the light emission control unit 61 causes some of the laser diodes 41 to emit light at the first timing, as illustrated in FIG. And the light emission control part 61 is a 2nd timing different from a 1st timing, as shown to (b) of FIG. 10, some laser diodes of the combination different from the laser diode 41 light-emitted at the 1st timing 41 is caused to emit light.

  Since the first pattern is formed due to the influence of light interference, the first pattern changes depending on the incident position and the amount of light incident on the transmissive diffusion plate 33. Accordingly, the light emission control unit 61 can change the first pattern by changing the light emission position at the first timing and the second timing.

  In addition, the three-dimensional measuring device 21 measures the distance to the object 11 at each of the first timing and the second timing. Then, the three-dimensional measuring device 21 generates three-dimensional information representing the distance to each position in the image based on the measurement result at the first timing and the measurement result at the second timing. Thereby, the three-dimensional measuring apparatus 21 can change the random pattern irradiated to the target object 11, for example, when measuring the distance to the target object 11 which has gloss on the surface.

  Thus, according to the pattern irradiation apparatus 60 which concerns on this embodiment, the random pattern irradiated to the target object 11 can be changed with a simple structure. In addition, the pattern irradiation apparatus 50 which concerns on 2nd Embodiment may be the structure provided with the light emission control part 61 similarly.

  As mentioned above, although embodiment of this invention was described, embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms.

DESCRIPTION OF SYMBOLS 10 Handling system 11 Target object 12 Tray 13 Robot 20,50,60 Pattern irradiation apparatus 21 Three-dimensional measuring apparatus 22 Recognition apparatus 23 Robot controller 30 Projection surface 31 Light emission part 32 Condensing part 33 Transmission diffuser plate 34 Light tunnel 35 Image formation part 36 Irradiation optical system 41 Laser diode 42 Collimator lens 45 Objective lens 51 Reflection diffuser 61 Light emission controller

JP 2001-147110 A

Claims (9)

A light emitting unit that emits coherent light;
The light by the light emitting portion is incident, a first plate which transmits or reflects incident light,
A second plate that receives light transmitted or reflected by the first plate and transmits or reflects the incident light;
An irradiation optical system that receives the light transmitted or reflected by the second plate, expands the incident light, and irradiates the projection surface;
With
The first plate has irregularities with a pitch smaller than the incident light spot, and displays a first pattern with a random luminance distribution on the projection plane,
The second plate is a pattern irradiation apparatus in which a random mask pattern is drawn, and a second pattern having a random luminance distribution with a spatial frequency different from that of the first pattern is displayed on the projection plane. The wavelength of light is λ, the beam diameter passing through the objective lens of the irradiation optical system is L, the optical path length from the objective lens of the irradiation optical system to the projection surface is z, and the magnification of the irradiation optical system is β. In this case, the second plate has the mask pattern in which the minimum pattern size M satisfies the following formula: M ≠ (λ × z) / (L × β)
The pattern irradiation apparatus according to claim 1. The pattern irradiation apparatus according to claim 1, wherein the second plate displays the second pattern including a pattern having a size larger than a pattern included in the first pattern on the projection surface. Wherein the first plate, the pattern irradiation device according to any one of claims 1 to 3 is a diffuser. The second plate, the pattern irradiation device according to claim 1 which is a photomask in any one of four.   The light emitting unit includes a plurality of light sources that emit coherent light.
  The pattern irradiation apparatus of any one of Claim 1 to 5. At a first timing, a part of the plurality of light sources is caused to emit light, and at a second timing different from the first timing, some light sources in a combination different from the light source emitted at the first timing The pattern irradiation apparatus according to claim 6 , further comprising: a light emission control unit that emits light. The pattern irradiation apparatus according to any one of claims 1 to 5 ,
A three-dimensional measuring device for measuring a distance to an object irradiated with light by the pattern irradiation device;
Bei to give a,
The light emitting unit includes a plurality of light sources that emit coherent light . The pattern irradiation device emits some of the plurality of light sources at a first timing, and differs from the light source emitted at the first timing at a second timing different from the first timing. It further includes a light emission control unit that emits light from some of the light sources of the combination,
The system according to claim 8, wherein the three-dimensional measurement apparatus measures a distance to the object at each of the first timing and the second timing.