JP6888429B2 - Pattern irradiation device, imaging system and handling system - Google Patents

Description

The present invention relates to a pattern irradiator, an imaging system and a handling system.

Conventionally, there is known a system in which an object (work) loaded on a tray is handled by a robot, the object is transported to a device in the next process, or a product is assembled using the object. 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 and handled based on the measurement result.

By the way, in such a system, a method of finding corresponding points from the left and right images taken by a stereo camera and measuring the distance from the coordinates of the two points by triangulation is widely used.

However, when a featureless object is an object, it becomes more difficult to find a corresponding point. For example, when there is a pattern on the wall, it is possible to find a corresponding point by capturing the pattern as a feature, but in the case of a wall of uniform color, it is difficult to capture the feature.

Therefore, in such a system, the accuracy of the distance measurement by the three-dimensional measuring device is improved by irradiating the object on the tray with the light of a binary random pattern by the pattern irradiating device to forcibly pattern the object. Techniques have been proposed (eg, Patent Documents 1 and 2).

However, when irradiating light with a binary random pattern, there is a problem that an erroneous point may be detected as a corresponding point because there are few patterns that can be expressed by the binary random pattern. For example, when three same patterns A are irradiated, it is possible to extract three patterns A from the image, but it is difficult to distinguish each of the three patterns A, which causes a problem of erroneous correspondence. Further, even when different patterns are projected, the same mishandling problem as when the same pattern is projected may occur due to the influence of sensor noise, the inclination of the projection surface, the pattern of the subject, and the like. Therefore, it is desired to reduce the probability that the same or similar patterns are generated by projecting a random pattern having three or more values that increases the number of patterns that can be expressed.

However, manufacturing a pattern irradiation device capable of irradiating a random pattern having three or more values by adjusting the projection surface of the pattern irradiation device or adjusting the focal position of the projection lens has many disadvantages in terms of cost.

The present invention has been made in view of the above, and an object of the present invention is to enable projection of a projected image having an N + 1 value or more from N value image information at low cost.

In order to solve the above-mentioned problems and achieve the object, the present invention comprises a light emitting unit that emits light, an image forming element that imparts N-value image information to the light emitted from the light emitting unit, and an image forming element. The image forming element comprises a projection optical system in which light to which image information of the N value is added is incident, and the incident light is magnified and irradiated to a projection surface. The projection optical system comprises the image forming. A projection lens designed in a PSF (Point Spread Function) that diffuses the image information of the N value given by the element is provided, and the image information of the N value given by the image forming element is N + 1 or more. The projected image as image information is irradiated on the projection surface.

In order to solve the above-mentioned problems and achieve the object, the present invention comprises a light emitting unit that emits light, an image forming element that imparts image information to the light emitted from the light emitting unit, and the image forming. The image forming element is provided with a projection optical system in which the light to which the image information is given by the element is incident and irradiates the projected surface with the incident light, and the image forming element is applied to the light irradiated to the projection surface. A pattern capable of resolving a part of the image information is provided, and the projection optical system includes a projection lens having a resolution at which the minimum unit of the image information given by the image forming element does not resolve. ..

According to the present invention, it is possible to project a projected image having an N + 1 value or more from N value image information at low cost.

FIG. 1 is a diagram showing a handling system according to the first embodiment. FIG. 2 is a diagram showing a configuration of a pattern irradiation device. FIG. 3 is a diagram showing an example of a random pattern given by the image forming element. FIG. 4 is a diagram schematically showing the function of a conventional projection lens. FIG. 5 is a diagram schematically showing the function of the projection lens. FIG. 6 is a graph showing an example of a brightness profile of a conventional projected image. FIG. 7 is a graph showing an example of the brightness profile of the projected image. FIG. 8 is a diagram showing an example of a projected image. FIG. 9 is a flowchart schematically showing a processing flow in the handling system. FIG. 10 is a diagram showing an example of an image obtained by capturing a conventional random pattern. FIG. 11 is a diagram showing an example of an image obtained by capturing a conventional random pattern. FIG. 12 is a diagram showing an example of a random pattern given by the image forming element according to the second embodiment. FIG. 13 is a diagram showing another example of the random pattern. FIG. 14 is a diagram showing another example of the random pattern. FIG. 15 is a diagram showing an example of a focus position adjusting pattern imparted by a part of the image forming element according to the third embodiment. FIG. 16 is a diagram showing a handling system according to the fourth embodiment. FIG. 17 is a flowchart schematically showing a processing flow in the handling system.

Hereinafter, embodiments of a pattern irradiation device, an imaging system, and a handling system will be described in detail with reference to the accompanying drawings.

(First Embodiment)
First, the outline of the handling system 10 of the first embodiment will be described. 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 device in the next process, and assembles the product using the object 11.

The handling system 10 includes a tray 12, a robot 13, a photographing system 14, and a control device 15. The tray 12 is loaded with at least one object 11. The photographing system 14 generates three-dimensional data representing the distances to each position on the surface of the object 11. The control device 15 recognizes the object 11 and controls the robot 13 based on the three-dimensional data from the photographing system 14.

The robot 13 moves and handles the arm with respect to any object 11 loaded on the tray 12 based on the instruction from the control device 15. Further, the robot 13 moves the object 11 handled based on the instruction from the control device 15 to a designated position or holds the object 11 in a designated posture. For example, the robot 13 opens and closes its claws to sandwich and handle the object 11. The robot 13 is not limited to such a configuration, and may be any mechanism as long as it can handle the object 11, and may be, for example, a robot hand that is attracted and taken out by an electromagnet or air. Further, a mechanism that detects the opening of the object 11 and inserts and grips the claw portion, or a mechanism that detects and sucks the apex of the object 11 may be used.

The photographing system 14 includes a pattern irradiation device 20 and a three-dimensional measuring device 21. The pattern irradiation device 20 includes a control unit composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. In the pattern irradiation device 20, various functions are realized by the CPU executing a ROM program in a predetermined procedure. The pattern irradiating device 20 irradiates the tray 12 on which the object 11 is loaded with a projected image based on a binary random pattern as monochromatic N-value image information. As a result, the exposed portion on the surface of each object 11 loaded on the tray 12 is irradiated with a projected image based on a binary random pattern.

The three-dimensional measuring device 21 includes a control unit composed of a CPU, a ROM, a RAM, and the like. In the three-dimensional measuring device 21, various functions are realized by the CPU executing a ROM program in a predetermined procedure. 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 the pattern irradiating device 20 irradiates the projected image based on the binary random pattern. , Measure using a stereo camera or the like.

The control device 15 includes a recognition device 22 and a robot controller 23. The control device 15 is a programmable computer composed of a CPU, a ROM, a RAM, and the like. In the control device 15, various functions are realized by the CPU executing a ROM program in a predetermined procedure. 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 coordinate measuring device 21. As an example, the recognition device 22 executes a matching process such as a matching process with a three-dimensional model or a surface matching process to recognize the position and orientation of each object 11. Further, 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 posture of each object 11 recognized by the recognition device 22 according to a control flow registered in advance. Then, the robot controller 23 causes the robot 13 to handle the designated object 11 on the tray 12.

In such a handling system 10, the pattern irradiation device 20 loads a projected image based on a binary random pattern on the tray 12 so as to improve the accuracy of the three-dimensional measurement by the three-dimensional measuring device 21. Irradiate the object 11. The reason for irradiating the projected image based on the binary random pattern in this way is as follows.

In the stereo camera used in the coordinate measuring device 21, a method of finding corresponding points from the left and right images and measuring the distance from the coordinates of the two points by triangulation is widely used. In order to obtain a high-precision and high-definition ranging image, it is necessary to find a larger number of corresponding points with high accuracy. However, when the featureless object is the object 11, it becomes more difficult to find the corresponding point. For example, when there is a pattern on the wall, it is possible to find a corresponding point by capturing the pattern as a feature, but in the case of a wall of uniform color, it is difficult to capture the feature. Therefore, according to the handling system 10, the position and orientation of each object 11 loaded on the tray 12 is accurately recognized by irradiating a projected image based on a binary random pattern and forcibly forming a pattern. However, the object 11 can be handled with high accuracy.

FIG. 2 is a diagram showing the configuration of the pattern irradiation device 20. In FIG. 2, the vertical direction is the Z direction, the direction perpendicular to the Z direction and perpendicular to the paper surface is the Y direction, and the direction perpendicular to the Z direction and the Y direction is the X direction.

As shown in FIG. 2, the pattern irradiation device 20 includes a light emitting unit 200. The light emitting unit 200 includes a laser diode 201 that is a light source that emits a visible monochromatic laser beam that is coherent light, a coupling lens 202 that deflects the light L emitted from the laser diode 201 into a parallel luminous flux, and a condenser lens 203. ,have.

Further, as shown in FIG. 2, the pattern illuminating device 20 internally reflects the transmission diffuser plate 204 arranged near the focal point of the condenser lens 203 and the light L transmitted through the transmission diffusion plate 204 to distribute the brightness. It has a light tunnel 205 and a light tunnel 205 that emits light so as to be uniform.

Further, as shown in FIG. 2, the pattern illuminating device 20 has an image forming element 206 arranged on the exit side of the light tunnel 205 in order to impart a binary random pattern to the light L, and a projection for projecting the light L. It has an optical system 207 and.

The laser diode 201 is a light emitting diode that emits blue laser light having a wavelength of 440 nm to 500 nm. Although the blue laser light is used in the present embodiment, the configuration is not limited to this, and laser light having a different wavelength may be used, or light other than the laser light may be used. However, monochromatic light is more desirable in consideration of ensuring the uniformity of brightness on the projection surface of the object 11 and suppressing the aberration in the projection optical system 207. Further, if the light emitted by the three-dimensional measuring device 21 can be detected, the laser diode 201 may emit laser light other than visible light.

The condensing lens 203 condenses the light L deflected as a parallel light flux by the coupling lens 202.

The transmission diffusing plate 204 is a diffusing plate whose diffusion angle is set to about 5 to 10 ° in half-value full width, and the light L focused on the focal point by the condensing lens 203 is not moistened or illuminance distribution is generated. Spread.

The light tunnel 205 is a tubular member having a hollow inside, and a reflecting surface 205a is formed on the inner wall surface to repeatedly reflect the light L to emit the light L while making the brightness distribution of the light L uniform. It is a transmission means that transfers in the lateral + A direction.

Although the light tunnel 205 is assumed to have a hollow tubular shape here, if it can be transmitted while being repeatedly reflected by the reflecting surface 205a, it is a solid member having a transparent member such as a glass pillar as a core. Is also good.

Generally, the larger the number of reflections in the light tunnel 205, that is, the number of times the light L is reflected by the reflection surface 205a, the more uniform the brightness distribution of the light L. On the other hand, the intensity of light L decreases due to the influence of attenuation due to reflection. The number of reflections varies depending on the length of the light tunnel 205 and the incident angle of the light L.

Therefore, it is desirable that the length of the light tunnel 205 is the minimum necessary length so that the brightness distribution can be made uniform while maintaining the transmission efficiency.

Further, since the light L transmitted through the light tunnel 205 is projected onto the image forming element 206 and given a binary random pattern, it is desirable that the light L has a size larger than that of the image forming element 206. That is, it is desirable that the size of the exit side opening and the incident side opening of the light tunnel 205 is equal to or larger than the size of the image forming element 206. Further, when the exit side opening of the light tunnel 205 is large, the portion of the light L that does not hit the image forming element 206 is wasted. Therefore, in order to improve the utilization efficiency of the light L, it is desirable that the exit side opening has a size necessary and sufficient for the light L to hit the image forming element 206 including the assembly accuracy.

Here, FIG. 3 is a diagram showing an example of a random pattern given by the image forming element 206. As shown in FIG. 3, the image forming element 206 is incident by drawing a mosaic-like binary random pattern (mask pattern) composed of a large number of blocks as a constituent unit with a reflective member such as aluminum or chrome. A binary random pattern is given to the light L.

The image forming element 206 forms a desired binary random pattern by transmitting a part of the light L and shading (or dimming) a part of the light L.

In the present embodiment, the image forming element 206 that forms a binary random pattern by reflection is used, but the binary random pattern is controlled by controlling the transmittance of an arbitrary cell like a liquid crystal element or the like. A transmissive image forming element for forming the above may be used.

The light L to which the binary random pattern is given by the image forming element 206 is incident on the projection optical system 207.

In the projection optical system 207, light L to which a binary random pattern is given by the image forming element 206 is incident. More specifically, the projection optical system 207 of the present embodiment irradiates the projection surface of the object 11 with a projected image in which the binary random pattern given by the image forming element 206 is a random pattern of three or more values. To do.

The projection optical system 207 includes a projection lens 207a. The projection lens 207a magnifies the light L to which a binary random pattern is given by the image forming element 206 to a designated magnification and irradiates the projection surface which is the object 11.

More specifically, the projection lens 207a has a resolution at which the smallest unit of the binary random pattern imparted by the image forming element 206 does not resolve. The resolution of the projection lens 207a may have a resolution at which the minimum unit of the binary random pattern does not resolve at least in part, but the resolution is binary random up to the vicinity of the center of the projection lens 207a having a particularly high resolution. It is more preferable that the smallest unit of the pattern has a resolution that does not resolve. The minimum unit referred to here means each block as a constituent unit constituting a random pattern.

Here, the projection lens 207a will be described.

First, a conventional projection lens will be described. Here, FIG. 4 is a diagram schematically showing the function of the conventional projection lens. FIG. 4A shows an example of the image forming element 206, FIG. 4B shows a PSF (Point Spread Function) of a conventional projection lens, and FIG. 4C is projected onto a projection surface. It shows a projected image. Conventionally, as shown in FIG. 4C, the image projected on the projection surface has the same pattern as the image forming element 206 in FIG. 4A. As described above, conventionally, FIG. 4B shows that the random pattern of the image forming element 206 is resolved on the projection surface, that is, the random pattern of the image forming element 206 and the projection pattern match as much as possible. A projection lens having such an ideal value of PSF is designed.

Next, the projection lens 207a of the present embodiment will be described. Here, FIG. 5 is a diagram schematically showing the function of the projection lens 207a. 5 (a) shows an example of the image forming element 206, FIG. 5 (b) shows the PSF of the projection lens 207a, and FIG. 5 (c) shows the projected image projected on the projection surface. As shown in FIG. 5B, in the PSF of the projection lens 207a of the present embodiment, the binary random pattern of the image forming element 206 is resolved at the time of projection at the optimum focal position (the most focused state). It is designed so that the binary random pattern of the image forming element 206 is diffused (blurred).

Here, FIG. 6 is a graph showing an example of a brightness profile of a conventional projected image. As shown in FIG. 6, the maximum value and the minimum value in the brightness profile of the projected image (the portion surrounded by the thick frame in FIG. 4 (c)) transmitted through the region containing three or more extreme values in the binary random pattern. Create three equally spaced luminance groups quantized with respect to the value. Here, since the maximum value of the brightness is 256 and the minimum value is 1, "brightness 1-85" is group 1, "brightness 86-170" is group 2, and "brightness 171-256" is group 3. According to the luminance profile shown in FIG. 6, in the past, extreme values existed only in groups 1 and 3.

On the other hand, FIG. 7 is a graph showing an example of the brightness profile of the projected image of the present embodiment. As shown in FIG. 7, of the binary random pattern given by the image forming element 206, the projected image (the portion surrounded by a thick frame in FIG. 5 (c)) transmitted through the region containing three or more extreme values. In the brightness profile, three brightness groups at equal intervals quantized based on the maximum value and the minimum value are created. Here, since the maximum value of the brightness is 205 and the minimum value is 27, “brightness 27-86” is group 1, “brightness 87-146” is group 2, and “brightness 147-205” is group 3. According to the luminance profile shown in FIG. 7, there are a plurality of intermediate extrema in each of the groups 1, 2 and 3 (only one in the group 2).

That is, the PSF of the projection lens 207a is between the maximum value and the minimum value of the brightness profile of the projected image transmitted through the region containing three or more extreme values among the binary random patterns given by the image forming element 206. Designed to have multiple intermediate extrema.

The projection lens 207a may be composed of a plurality of lenses. In this case, the maximum value and the minimum value of the brightness profile of the projected image in which the PSF formed by all the plurality of lenses passes through the region containing three or more extreme values among the binary random patterns given by the image forming element 206. It is designed so that there are multiple intermediate extremes between the values.

In other words, the PSF of the projection lens 207a is based on the maximum value and the minimum value of the brightness profile of the projected image transmitted through the region containing three or more extreme values among the binary random patterns given by the image forming element 206. It is designed so that the extremum of the brightness profile of the projected image exists in each of the three equally spaced brightness groups quantized in.

As shown in FIG. 5 (c) in this way, the binary random pattern given by the image forming element 206 of FIG. 5 (a) by convolving the PSF has the optimum focal position (most focus). In the state of matching), a random pattern of three or more values is formed and projected onto the projection surface in a diffused state (blurred state).

Here, FIG. 8 is a diagram showing an example of a projected image. For example, when light L to which a binary random pattern shown in FIG. 3 is applied is applied to a projection surface which is an object 11 via a projection optical system 207, a luminance distribution of three or more values is shown as shown in FIG. The projected image of the pattern is displayed.

As an example, the three-dimensional measuring device 21 is based on the images taken by the stereo cameras, and specifically, by comparing two images in which the baseline direction and the horizontal direction coincide with each other in a pseudo manner. A parallax image, that is, three-dimensional data, is generated from the parallax in the horizontal direction of. Then, the three-dimensional measuring device 21 calculates the distance to the object 11 based on the parallax image. In other words, the distance from the image data on which the random pattern given by the image forming element 206 is projected to the object 11 is calculated.

Next, the processing flow in the handling system 10 will be briefly described. Here, FIG. 9 is a flowchart schematically showing a processing flow in the handling system 10.

As shown in FIG. 9, first, the pattern irradiating device 20 of the photographing system 14 irradiates the object 11 with the light L to which the binary random pattern shown in FIG. 3 is applied (step S100).

The three-dimensional measuring device 21 of the photographing system 14 photographs the image on the tray 12 with a stereo camera (step S101).

Next, the three-dimensional measuring device 21 acquires three-dimensional information (three-dimensional data) using each texture information of the image taken by the stereo camera (step S102).

Although only the three-dimensional data acquisition method using a stereo camera has been described here, another three-dimensional data acquisition technique using a monocular camera, for example, a phase shift method may be used.

Next, the recognition device 22 of the control device 15 recognizes the object 11 based on the information of the three-dimensional image formed in step S102 (step S103).

Then, the robot controller 23 of the control device 15 operates the robot 13 based on the recognized position and posture of each object 11 to take out the object 11 (step S104).

When the robot 13 takes out the object 11, the handling system 10 repeats the steps S101 to S104 for the new object 11 until all the objects 11 are processed.

As described above, according to the present embodiment, the projection image of the N + 1 value or more is projected from the N value image information (random pattern) at low cost regardless of the projection surface adjustment of the pattern irradiation device or the focal position adjustment of the projection lens. Can be made possible.

In the present embodiment, a binary random pattern is applied as N-value image information, but the present invention is not limited to this, and a random pattern of three or more values may be applied.

(Second Embodiment)
Next, the second embodiment will be described. The handling system 10 of the second embodiment is different from the handling system 10 of the first embodiment in that a pattern having both periodicity and randomness is used as the mask pattern given by the image forming element 206 of the pattern irradiation device 20. different. Hereinafter, in the description of the second embodiment, the description of the same part as that of the first embodiment will be omitted, and the parts different from the first embodiment will be described.

As described in the first embodiment, it is known that a random pattern is effective in the mask pattern formed by the image forming element 206 of the pattern irradiating device 20. However, the random pattern is truly effective only when the positional relationship between the pattern irradiation device 20 and the three-dimensional measuring device 21 is fixed.

For example, FIG. 10 shows that when the distance from the pattern irradiating device 20 to the object 11 and the distance from the three-dimensional measuring device 21 to the object 11 are equal, the random pattern irradiated by the pattern irradiating device 20 is measured by the three-dimensional measuring device. This is an example of an image captured by No. 21.

On the other hand, FIG. 11 shows that when the distance from the pattern irradiating device 20 to the object 11 and the distance from the three-dimensional measuring device 21 to the object 11 are different, the random pattern irradiated by the pattern irradiating device 20 is measured by the three-dimensional measuring device. This is an example of an image captured by No. 21. In the example shown in FIG. 11, the distance from the coordinate measuring device 21 to the object 11 and the distance from the pattern irradiation device 20 to the object 11 are set in a 2: 3 relationship.

As shown in FIGS. 10 and 11, when the positional relationship between the pattern irradiation device 20 and the three-dimensional measuring device 21 changes, the pattern is simply enlarged in the random pattern (in FIG. 11, 1. Enlarged 5 times). When the three-dimensional measuring device 21 approaches the object 11 in this way and the measurement conditions change and the random pattern is enlarged, a measurement error in the three-dimensional measuring device 21 occurs. More specifically, in the case of the stereo camera included in the three-dimensional measuring device 21, erroneous matching occurs due to a plurality of similar patterns being found in a desired parallax search range.

Therefore, as a random pattern, a pattern having both periodicity and randomness is effective as a pattern that can maintain its uniqueness even if it is enlarged or reduced.

Therefore, in the present embodiment, as a mask pattern given by the image forming element 206 of the pattern irradiation device 20, a random value is added to a pattern having both periodicity and randomness (for example, a quasi-periodic function and a quasi-periodic function). The thing) is used.

Here, FIG. 12 is a diagram showing an example of a random pattern given by the image forming element 206 according to the second embodiment. As shown in FIG. 12, the random pattern given by the image forming element 206 according to the second embodiment is white if f (x, y)> 0 based on the quasi-periodic function of the following equation, and f (x, x, y) If <= 0, it is determined as black.

The random pattern shown in FIG. 12 is a pattern when n = 5 in Equation 1 as shown in the following equation.

Further, FIG. 13 is a diagram showing another example of the random pattern. In the example shown in FIG. 13, the random pattern given by the image forming element 206 is determined by the value obtained by combining the two quasi-periodic functions. The random pattern shown in FIG. 13 is a combination of the pattern of n = 5 and the pattern of n = 7 in Equation 1 as shown in the following equation.

Further, FIG. 14 is a diagram showing another example of the random pattern. In the example shown in FIG. 14, the random pattern given by the image forming element 206 is determined by adding a random value to the value obtained by combining the two quasi-periodic functions shown in FIG.

As described above, according to the present embodiment, even if the positional relationship between the three-dimensional measuring device 21 (stereo camera or the like) and the pattern irradiating device 20 (projecting device) changes and the pattern is enlarged, the desired measurement conditions change. Since it is difficult (in the case of a stereo camera, it is difficult to find a similar pattern in the desired parallax search range), measurement errors are less likely to occur.

The quasi-periodic function and the quasi-periodic function with a random value added are not limited to the case of projecting a projected image of N + 1 value or more from N value image information, and N value projected image from N value image information. It is also effective when projecting.

In the present embodiment, a binary random pattern is applied as N-value image information, but the present invention is not limited to this, and a random pattern of three or more values may be applied.

(Third Embodiment)
Next, the third embodiment will be described. The handling system 10 of the third embodiment is provided with a pattern (for example, a line chart) capable of resolving without blurring at the time of projection on a part of the image forming element 206 of the pattern irradiation device 20. Different from system 10. Hereinafter, in the description of the third embodiment, the description of the same part as that of the first embodiment will be omitted, and the parts different from the first embodiment will be described.

As described in the first embodiment, the PSF of the projection lens 207a included in the projection optical system 207 of the pattern irradiation device 20 is such that the binary random pattern of the image forming element 206 is not resolved at the time of projection, that is, image forming. It is designed so that the binary random pattern of the element 206 is diffused (blurred).

By the way, since the pattern irradiation device 20 (projection device) can be installed at various distances from the object 11 and the coordinate measuring device 21, it is necessary to set the focal position to an optimum position. However, since the mask pattern is projected in a blurred state at any focal position, it is difficult for the pattern irradiator 20 whose projection magnification changes depending on the installation distance to adjust the optimum focal position.

Therefore, in the present embodiment, a pattern (for example, a line chart) capable of resolving without blurring at the time of projection is provided on a part of the image forming element 206 of the pattern irradiation device 20, and the focal position is used by using the obtained luminance information. Is to be adjusted.

Here, FIG. 15 is a diagram showing an example of a focus position adjusting pattern imparted by a part of the image forming element 206 according to the third embodiment.

In this embodiment, it is premised that the projection optical system 207 of the pattern irradiation device 20 is designed so that the desired blur occurs at the optimum focal position (the position where the focus is in focus). It has become.

As shown in FIG. 15, a part of the mask pattern (focus position adjusting pattern) given by the image forming element 206 of the pattern irradiating device 20 is a line chart. In particular, as shown in FIG. 15, in the given line chart, the line width of the line is changed from one end to the other end. By changing the line width of the line from one end to the other end in this way, the black-and-white interval can be changed depending on the position of the line. As a result, even when the pattern irradiation device 20 is installed at various distances from the object 11 and the coordinate measuring device 21 and the projection magnification changes, the pattern irradiation device 20 is optimally obtained from the luminance information. It is possible to adjust the focal position with a wide line width.

The focus position may be adjusted sensually while visually checking the line chart, which is a part of the projected mask pattern (focus position adjustment pattern), or by using a shooting module such as a camera. The black and white brightness may be adjusted so as to have the largest inclination.

As described above, according to the present embodiment, the optimum focal position can be adjusted while observing (or measuring) the focal position adjusting pattern (for example, a line chart) that can be resolved without blurring during projection. It is possible to easily project a desired blurred pattern in adjusting the optimum focal position.

(Fourth Embodiment)
Next, the fourth embodiment will be described. The point that the pattern irradiation device 20 of the handling system 10 of the fourth embodiment determines the optimum focal position by using the three-dimensional data (three-dimensional information) acquired by the three-dimensional measuring device 21 and fed back is determined. It is different from the handling system 10 of the first embodiment. Hereinafter, in the description of the fourth embodiment, the description of the same part as that of the first embodiment will be omitted, and the parts different from the first embodiment will be described.

As described in the first embodiment, the PSF of the projection lens 207a included in the projection optical system 207 of the pattern irradiation device 20 is such that the binary random pattern of the image forming element 206 is not resolved at the time of projection, that is, image forming. It is designed so that the binary random pattern of the element 206 is diffused (blurred).

By the way, since the pattern irradiation device 20 (projection device) can be installed at various distances from the object 11 and the coordinate measuring device 21, it is necessary to set the focal position to an optimum position. However, since the mask pattern is projected in a blurred state at any focal position, it is difficult for the pattern irradiator 20 whose projection magnification changes depending on the installation distance to adjust the optimum focal position.

Therefore, in the present embodiment, the pattern irradiation device 20 is designed to determine the optimum focal position by using the three-dimensional data (three-dimensional information) acquired by the three-dimensional measuring device 21 and fed back. is there.

Here, FIG. 16 is a diagram showing a handling system 10 according to a fourth embodiment. The pattern irradiation device 20 of the handling system 10 of the present embodiment includes a determination means 24. The determination means 24 determines the optimum focal position by using the three-dimensional data (three-dimensional information) acquired by the three-dimensional measuring device 21 and fed back. The determination means 24 is realized by the CPU executing the ROM program in a predetermined procedure.

FIG. 17 is a flowchart schematically showing a processing flow in the handling system 10. As shown in FIG. 17, first, the pattern irradiation device 20 of the photographing system 14 changes the focal position of the projection optical system 207, and for example, the light L to which the binary random pattern shown in FIG. 3 is given is the object 11. (Step S110).

The three-dimensional measuring device 21 of the photographing system 14 photographs the image on the tray 12 with a stereo camera (step S101).

Next, the three-dimensional measuring device 21 acquires three-dimensional information (three-dimensional data) using each texture information of the image taken by the stereo camera (step S102).

Further, the three-dimensional measuring device 21 feeds back the three-dimensional information (three-dimensional data) to the pattern irradiation device 20 (step S111).

The determination means 24 of the pattern irradiation device 20 has acquired a set target value (three-dimensional data for all pixels in the acquired image) for the three-dimensional information (three-dimensional data) fed back from the three-dimensional measuring device 21. It is determined whether or not the ratio (density) of pixels, the variation in the distance on the surface of the object 11 when the three-dimensional information (three-dimensional data) of the flat object 11 is acquired, and the like are satisfied (step S112).

When it is determined that the set target value is not satisfied for the three-dimensional information (three-dimensional data) (No in step S112), the pattern irradiation device 20 returns to step S110, changes the focal position, and directs the object 11 to the object 11. The light L to which a binary random pattern is applied is irradiated (step S110).

On the other hand, when the pattern irradiation device 20 determines that the set target value is satisfied with respect to the three-dimensional information (three-dimensional data) (Yes in step S112), it is assumed that the focus position is optimal. After that, the three-dimensional measuring device 21 passes the three-dimensional information (three-dimensional data) to the recognition device 22 of the control device 15 (step S113).

The recognition device 22 of the control device 15 recognizes the object 11 based on the information of the three-dimensional image formed in step S102 (step S103).

Then, the robot controller 23 of the control device 15 operates the robot 13 based on the recognized position and posture of each object 11 to take out the object 11 (step S104).

For example, the pattern irradiation device 20 may evaluate the density as to whether the three-dimensional information (three-dimensional data) of each pixel is acquired. Further, the pattern irradiator 20 can evaluate the density of the three-dimensional information (three-dimensional data) and the variation of the three-dimensional information (three-dimensional data) by using the flat design work.

As described above, according to the present embodiment, it is not necessary to use another pattern other than the mask pattern used for the measurement as in the third embodiment, so that the mask pattern used for the measurement is not sacrificed and the optimum focus position is adjusted. The desired blurred pattern can be projected.

Although the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other embodiments.

10 Handling system 11 Object 13 Robot 14 Imaging system 15 Control device 20 Pattern irradiation device 21 Coordinate-measuring device 200 Light emitting unit 201 Light source 206 Image forming element 207 Projection optical system 207a Projection lens

Japanese Unexamined Patent Publication No. 2001-147110 Japanese Unexamined Patent Publication No. 2005-043233

Claims (18)

A light emitting part that emits light and
An image forming element that imparts N-value image information to the light emitted from the light emitting unit, and
A projection optical system in which light to which image information of the N value is added is incident by the image forming element, and the incident light is magnified and irradiated to the projection surface.
With
The projection optical system includes a projection lens designed as a PSF (Point Spread Function) in which the image information of the N value given by the image forming element is diffused, and the N value given by the image forming element. The projection surface is irradiated with a projected image in which the image information of is N + 1 value or more.
A pattern irradiation device characterized in that. The projection optical system includes a projection lens having a resolution at which the minimum unit of the image information of the N value given by the image forming element is not resolved.
The pattern irradiation device according to claim 1. The PSF of the projection lens is between the maximum value and the minimum value of the brightness profile of the projected image transmitted through a region containing N + 1 or more extreme values in the image information of the N value given by the image forming element. Designed to have multiple intermediate extrema,
The pattern irradiation device according to claim 1. The PSF of the projection lens is based on the maximum value and the minimum value of the brightness profile of the projected image transmitted through a region containing N + 1 or more extreme values in the image information of the N value given by the image forming element. It is designed so that the extremum of the brightness profile of the projected image exists in each of the N + 1 brightness groups quantized in.
The pattern irradiation device according to claim 1. The N-value image information given to the light emitted from the light emitting unit by the image forming element is binary image information.
The pattern irradiation device according to any one of claims 1 to 4, wherein the pattern irradiation device is characterized. The binary image information given by the image forming element to the light emitted from the light emitting unit is a mosaic-like binary random pattern.
The pattern irradiation device according to claim 5. The image forming element forms the binary random pattern by reflection.
The pattern irradiation device according to claim 6. The image forming element forms the binary random pattern by transmission.
The pattern irradiation device according to claim 6. The image forming element determines the binary image information by a value obtained by combining one or more quasi-periodic functions with respect to the binary random pattern.
The pattern irradiation device according to any one of claims 6 to 8, wherein the pattern irradiation device is characterized. The image forming element determines the binary image information by a value obtained by combining one or more quasi-periodic functions with respect to the binary random pattern and a random value.
The pattern irradiation device according to any one of claims 6 to 8, wherein the pattern irradiation device is characterized. The quasi-periodic function is given by the following equation.

The pattern irradiation device according to claim 9 or 10. The light emitting unit has a plurality of light sources that emit light.
The pattern irradiation device according to any one of claims 1 to 11. A light emitting part that emits light and
An image forming element that imparts image information to the light emitted from the light emitting unit, and
A projection optical system in which light to which the image information is added is incident by the image forming element and the incident light is irradiated to the projection surface.
With
The image forming element is provided with a pattern capable of resolving a part of the image information applied to the light applied to the projection surface.
The projection optical system includes a projection lens having a resolution at which the smallest unit of the image information given by the image forming element does not resolve.
A pattern irradiation device characterized in that. The projection lens has a resolution at which the smallest unit of the image information imparted by the image forming element does not resolve at least near the center of the projection lens.
The pattern irradiation device according to claim 13. The image forming element is a line chart in which the line width of the line is changed from one end to the other end of the pattern provided in a part of the image information.
The pattern irradiation device according to claim 13. Whether or not the target value is satisfied for the three-dimensional information fed back from the three-dimensional measuring device that measures the three-dimensional information based on the image information irradiated from the pattern irradiating device each time the focal position of the projection optical system is changed. When the target value is satisfied, a determination means for setting the focal position as the optimum focal position is provided.
The pattern irradiation device according to claim 12 or 13. The pattern irradiation device according to any one of claims 1 to 16.
A three-dimensional measuring device that generates three-dimensional data representing the distance to the projection surface irradiated with light by the pattern irradiation device, and
A shooting system characterized by being equipped with. A robot that moves an object and
The pattern irradiation device according to any one of claims 1 to 16 , wherein the object is a projection surface.
A three-dimensional measuring device that generates three-dimensional data representing the distance to the object irradiated with light by the pattern irradiating device, and a three-dimensional measuring device.
A control device that recognizes the object and controls the robot based on the three-dimensional data generated by the three-dimensional measuring device.
A handling system characterized by being equipped with.

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