JP2010263273A - Robot system and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a robot system for precisely detecting the position of a workpiece from blur images obtained by imaging the workpiece. <P>SOLUTION: The robot system includes: a robot 10 that works on a workpiece W, a stage 72 that places the workpiece W and has a marker 74 emitting light of a plurality of wavelengths, and an imaging apparatus 20 for capturing the image of the workpiece W and that of the marker 74 as the same image. The robot system also includes: a point diffusion function calculation section 35 for extracting a trajectory image 100 of the marker 74 from a deteriorated image B including a motion blur captured by the imaging apparatus 20 to calculate a point diffusion function from the trajectory image 100; an image generation section 37 for generating a non-deteriorated original image from the deteriorated image B by converting the deteriorated image B by the calculated point diffusion function; and a position calculation section 39 for calculating a position of the workpiece W from the generated original image. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a robot system that performs work on a work target and a method for controlling the robot system.

  In various production sites, industrial robots are frequently used for work automation and labor saving. Such an industrial robot includes an imaging device such as a camera to capture an image of a work target, and performs image processing on the captured image to detect the position of the work target. When the work object and the imaging device are moving relatively, motion blur occurs in the captured image. In recent years, high-accuracy positioning has been demanded along with the speeding up and sophistication of work by industrial robots. Therefore, it is important to correct the motion blur in the captured image.

  As such a motion blur correction method, there is a method of restoring a non-blurred image by estimating how the blur is occurring and calculating an inverse characteristic of the image. As an example of the method, information related to the movement of the imaging device is detected by an angular velocity sensor provided in the imaging device, and a point spread function (PSF: Point Spread Function) indicating characteristics of blur due to the motion is obtained based on the detected information. . A method of performing blur correction, that is, a method of restoring an original image from a blurred image by performing arithmetic processing such as Fourier transform and inverse Fourier transform using this point spread function is known (for example, Patent Document 1 and Patent Document 2). reference).

JP 2008-118644 A JP 2008-11424 A

  In the above method, since the angular velocity sensor is installed in the moving part (imaging device) of the industrial robot, depending on the work environment and the work content, the temperature fluctuation and the angular velocity change become large, and the information output from the angular velocity sensor Reliability and accuracy may be reduced. Further, in order to obtain the point spread function with high accuracy, it is necessary to synchronize the imaging timing of the imaging device and the signal output from the angular velocity sensor. However, for this purpose, there is a problem that the control becomes complicated and a lot of cost and labor are required. Further, since only the movement of the imaging device can be detected, there is a problem that when the work object is moving, the blur characteristic due to the movement of the work object is not sufficiently reflected in the required point diffusion function.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  (Application Example 1) A robot that performs work on a work object, a stage on which the work object is placed and a marker that emits light of a plurality of wavelengths, the work object, and the marker A point diffusion that extracts a locus image of the marker from a deteriorated image including motion blur imaged by the imaging device, and calculates a point diffusion function from the locus image. From the function calculation unit, an image generation unit that generates an original image that has not deteriorated from the deteriorated image by converting the deteriorated image using the calculated point diffusion function, and the generated original image And a position calculation unit for calculating a position of the work object.

  According to this structure, the marker which discharge | releases the light of several wavelengths, ie, the light of a different color, is provided in the stage in which a work target object is mounted. The degraded image of the work object imaged by the imaging device, that is, the so-called blurred image includes the locus image of the marker. Since the marker trajectory image is composed of continuous trajectories of different colors, the constituent elements of the point diffusion function such as the direction of motion that causes blurring can be easily obtained from the entire trajectory image. Therefore, the point spread function can be calculated with high accuracy. Then, an unblurred original image can be generated from the blurred image using the calculated point spread function, and the position of the work object can be calculated from the generated original image. That is, it is possible to provide a robot system that can easily calculate the position of a work object with a simple configuration and control without using an angular velocity sensor or the like. In addition, since the relative movement between the stage on which the work object is placed and the imaging apparatus is directly picked up, the blur characteristics due to the relative movement of the work object can be sufficiently reflected in the point spread function.

  (Application Example 2) The robot system as described above, wherein the marker sequentially emits light of different wavelengths at a specific period.

  (Application Example 3) The robot system described above, wherein the marker emits light of at least three different wavelengths.

  According to this configuration, the obtained marker trajectory image is a strip-shaped trajectory image in which three different colors are arranged in order. Therefore, it is possible to know the direction of movement (start point and end point) from the arrangement order of the colors constituting the trajectory image. In addition, since the color changes at a specific cycle, the average speed when the color is emitting can be known from the length of each color constituting the trajectory image. In addition, it is possible to know the speed change by comparing the average speed of each color.

  (Application Example 4) The robot system as described above, wherein a plurality of the markers are provided on the stage.

  According to this configuration, the relative rotation or movement of the stage can be known more accurately by analyzing the trajectory image.

  (Application Example 5) The robot system as described above, wherein the plurality of markers emit light having different wavelengths at a certain point in time.

  According to this configuration, it is possible to specify the marker imaged in the blurred image.

  (Application example 6) A method for controlling a robot system that performs work on a work object, wherein the work object placed on a stage having a marker that emits light of a plurality of wavelengths is captured by an imaging device An imaging step of taking an image together with the marker, a point diffusion function calculating step of extracting a locus image of the marker from a deteriorated image including motion blur imaged by the imaging device, and calculating a point diffusion function from the locus image; An image generation step for generating an original image that is not deteriorated from the deteriorated image by performing image conversion on the deteriorated image using the calculated point spread function, and the work object from the generated original image And a position calculating step for calculating a position.

  According to this method, since the stage on which the work object is placed is provided with a marker that emits light of a plurality of wavelengths, that is, light of different colors, the work object imaged by the imaging device is deteriorated. An image, a so-called blurred image, can include a trajectory image of the marker. Since the marker trajectory image is composed of continuous trajectories of different colors, the constituent elements of the point diffusion function such as the direction of motion that causes blurring can be easily obtained from the entire trajectory image. Therefore, the point spread function can be calculated with high accuracy. Then, an unblurred original image can be generated from the blurred image using the calculated point spread function, and the position of the work object can be easily calculated from the generated original image. That is, the position of the work object can be calculated by a simple method without using an angular velocity sensor or the like. In addition, since the relative movement between the stage on which the work object is placed and the imaging device is directly picked up, the blur characteristics due to the relative movement of the work object can be sufficiently reflected in the point spread function.

The figure which shows the structural example of a robot system. The figure explaining the stage in which the workpiece | work which is a work target object is mounted. The flowchart which shows the flow of the position detection method of a workpiece | work. The figure which shows the image of the workpiece | work imaged with the camera. The figure explaining the stage of 2nd Example. The figure which shows the image of the workpiece | work concerning 2nd Example. The figure explaining a 1st modification. The figure explaining a 2nd modification.

  The robot system of the present embodiment will be described with reference to FIGS. FIG. 1 is a diagram illustrating a configuration example of a robot system, and FIG. 2 is a diagram illustrating a stage on which a work, which is a work target, is placed.

(Robot system configuration)
(First embodiment)
As shown in FIG. 1, the robot system 5 includes a robot 10, a workpiece placement unit 70 that places and transports a workpiece W that is a work target, and a control unit 50. The robot 10 is a so-called articulated robot, and includes a base 25, arms 17A and 17B, a wrist portion 18 including a robot hand 19, and a first shaft 12 and a first shaft 12 which are joint portions that rotatably support each. It is comprised from the 2 axis | shaft 14, the 3rd axis | shaft 16, and the camera 20 as an imaging device.

  The robot 10 is installed on the installation surface by the base 25. The base 25 includes the first rotation shaft 11 and can rotate the main body of the robot 10 above the base 25 about a vertical axis with respect to the installation surface. An arm 17 </ b> A is rotatably attached to the base 25 via the first shaft 12. The arm 17A includes a second rotating shaft 13, and the arm 17A itself can rotate in the axial direction. An arm 17B is rotatably attached to the arm 17A via the second shaft 14. The arm 17B includes a third rotating shaft 15, and the arm 17B itself can rotate in the axial direction. A wrist 18 is rotatably attached to the arm 17B via a third shaft 16.

  A robot hand 19 is provided at the tip of the wrist 18 and performs work on the workpiece W. A camera 20 is attached to the tip of the wrist 18. The camera 20 functions as an eye of the robot 10 so to speak, and for example, images the direction in which the robot hand 19 is working by an image pickup device such as a CCD.

  The first to third shafts 12, 14, 16, the first to third rotating shafts 11, 13, 15 and the robot hand 19 are driven by a plurality of actuators (not shown) operated by a motor (not shown) or pneumatic equipment. , Configured to rotate. The plurality of actuators are driven based on a control signal sent from the control unit 50 via the cable 85. In addition, the camera 20 images the workpiece W and the like with a predetermined exposure time, and the captured image signal is sent to the control unit 50 via the cable 86.

  The work placing unit 70 includes a stage 72 on which the work W is placed. In stage 72, the robot 10 performs an operation on the workpiece W. The stage 72 has a stage surface 72a on which the workpiece W is placed, and the stage surface 72a includes one or more markers 74 that emit light having a plurality of wavelengths. Details of the marker 74 will be described later. For example, the work W is transported by a belt conveyor (not shown), is carried into the stage 72 of the work placing unit 70, and after the work by the robot 10 is performed, it is carried out to the next work placing unit 70 or the next process. . The workpiece placement unit 70 itself may be conveyed by a belt conveyor.

  The control unit 50 includes at least an image processing device 30, a robot operation control unit 40, a mark generation unit 45, and a computer 60. The image processing apparatus 30 includes at least an image input unit 32 and a position information acquisition unit 34. The image processing device 30 captures a workpiece W and a marker 74 that are captured by the camera 20 of the robot 10 and input via the image input unit 32. The position information of the workpiece W is acquired by processing the included image. The position information acquisition unit 34 includes a point spread function calculation unit 35, an image generation unit 37, and a position calculation unit 39, performs various arithmetic processes, and acquires the position information of the workpiece W. The operation of the position information acquisition unit 34 will be described later.

  The robot operation control unit 40 controls the operation of the robot 10 described above based on a command from the computer 60. The mark generating unit 45 controls the marker 74 provided on the stage surface 72a on which the workpiece W is placed, and emits light having a plurality of wavelengths. The computer 60 functions as a central processing unit, and organically cooperates hardware resources such as a CPU, RAM, ROM, HDD, sequencer, and robot controller (not shown) with various software stored in the ROM, HDD, and the like. By operating, the robot 10, the image processing device 30, the mark generation unit 45, and the like are collectively controlled.

  Here, the stage 72 of this embodiment and the marker 74 provided on the stage 72 will be described. As shown in FIG. 2A, the stage 72 is formed in a rectangular shape. For example, a marker 74 is provided near one corner of the stage surface 72a. In the present embodiment, the case where one marker 74 is provided will be described for the sake of simplicity, but the number of markers 74 is not limited to this. A plurality of markers 74 may be provided.

  The marker 74 includes a light emitting unit 75. The light emitting unit 75 includes a red light source 76R, a green light source 76G and a blue light source 76B, an optical fiber 77, and a lens 78, as shown in FIG. The red light source 76R, the green light source 76G, and the blue light source 76B are configured by, for example, red, green, and blue LEDs (light emitting diodes). The optical fiber 77 is composed of a large number of fibers, the light collecting portion 77a is branched into three, and the light emitting portion 77b is combined into one. The three light collecting portions 77a branched to face the red light source 76R, the green light source 76G, and the blue light source 76B, respectively. The light emitting portion 77 b faces the lens 78 provided on the stage surface 72 a of the stage 72.

  Since it has such a structure, the light emitted from the red light source 76R, the green light source 76G, and the blue light source 76B is condensed by the condensing unit 77a of the optical fiber 77, and the light is emitted from the light emitting unit 77b to the lens. The light is emitted from the light emitting unit 75, that is, the marker 74 through 78.

  The red light source 76R, the green light source 76G, and the blue light source 76B emit light according to the control signal C shown in FIG. 2C output from the mark generation unit 45 of the control unit 50 shown in FIG. As shown in the timing chart of FIG. 2C, the red light source 76R starts emitting at time t0 and continues emitting until time t1. Next, the green light source 76G starts light emission at time t1, and continues to emit light until time t2. Next, the blue light source 76B starts to emit light at time t2 and continues to emit light until time t3. Thereafter, this operation is repeated according to the control signal C.

  That is, the marker 74 emits light in the order of red, green, and blue in the period ta shown in FIG. In other words, the marker 74 can continuously emit light having different wavelengths at a specific period ta. Note that the periods TA and ta shown in FIG. 2C can be changed by setting the control signal C output from the mark generation unit 45.

  The workpiece W placed on the stage 72 is formed in, for example, a rectangular plate shape as shown in FIG. 2A, and three through holes are provided in the plane portion. The workpiece W is preferably placed avoiding the marker 74 provided on the stage surface 72a.

(About work in robot systems)
An operation using the above-described robot system 5 will be described with reference to FIGS. 1 and 2. The robot 10 of the robot system 5 performs work on the workpiece W transferred to the stage 72 by a belt conveyor (not shown). In the present embodiment, in order to improve the production efficiency and to generalize and simplify the equipment, since the work W alignment device and the positioning device are not provided, the work W is transported in a random posture, and each work is unique. To be implemented. Therefore, the robot 10 needs to detect the position and orientation of the workpiece W that performs the work. Accordingly, the robot 10 detects the position of the workpiece W by imaging the workpiece W placed on the stage 72 using the camera 20 shown in FIG.

  For example, it is assumed that the workpiece W is placed on the stage 72 in a layout as shown in FIG. In order to detect the position of the work W, the work W on the stage 72 is imaged using the camera 20 provided at the tip of the wrist 18 of the robot 10. At this time, it is preferable that the movement of the wrist portion 18 of the robot 10 is stopped or the workpiece W is stopped. However, in such a method, work and moving operations are interrupted, and work efficiency is significantly reduced. Therefore, in general, imaging is performed in a state where both are moving. In addition, the camera 20 captures an image by opening the shutter over a predetermined exposure time.

  As a result, the captured image of the workpiece W often becomes a so-called blurred image B including motion blur, and the position of the workpiece W cannot be detected as it is. Therefore, some image processing is necessary. As an image processing method, for example, there is a method of restoring a non-blurred original image by estimating how the blurred image is blurred and calculating the inverse characteristic of the blurred image.

(About workpiece position detection method)
Here, a workpiece position detection method using a point diffusion function as a parameter representing how the image is blurred will be described with reference to FIGS. FIG. 3 is a flowchart showing the flow of the workpiece position detection method, and FIG. 4 is a diagram showing an image of the workpiece captured by the camera.

As shown in FIG. 3, this position detection method includes a workpiece carry-in step S11, a marker & workpiece imaging step S12, an image input step S13, a point diffusion function calculation step S14, an image generation step S15, and a workpiece position calculation. Step S16.
In the workpiece carrying-in process S11, the workpiece W is conveyed by a belt conveyor or the like and supplied to the stage 72 of the workpiece placing unit 70 in the robot system 5 shown in FIG. At this time, since the workpiece W is supplied in a random posture, it is not known what posture the workpiece W is currently in. Therefore, the process proceeds to the next step.

  In the marker and workpiece imaging step S12, the workpiece W placed on the stage 72 is imaged using the camera 20 shown in FIG. At this time, imaging is performed so that the marker 74 provided on the stage surface 72a on which the workpiece W is placed also falls within the same visual field. However, since the camera 20 and the workpiece W (stage 72) are in a relatively moving state, an image to be captured becomes a so-called blurred image B including motion blur.

  As shown in FIG. 4A, the blurred image B includes an image Bw of the work W including motion blur and a trajectory image 100 of the marker 74. As described above, since the marker 74 emits light in the order of red, green, and blue in the period ta shown in FIG. 2C, the trajectory image 100 is a red belt-like trajectory image as shown in FIG. 4B. 100r, a green belt-like locus image 100g, and a blue belt-like locus image 100b. In the present embodiment, the red locus image 100r, the green locus image 100g, and the blue locus image 100b have different lengths Lr, Lg, and Lb of the belt-like portions.

  In the image input step S13 illustrated in FIG. 3, the blurred image B including the trajectory image 100 captured by the camera 20 is captured as an image signal into the image input unit 32 of the image processing device 30 of the control unit 50 illustrated in FIG. The captured blur image B is sent to the position information acquisition unit 34.

  In the point spread function calculating step S14 shown in FIG. 3, the locus image 100 is extracted from the blurred image B and the point spread function is calculated. The method for calculating the point spread function is not particularly limited. A known calculation method may be applied. Note that the trajectory image 100 has information on the spatial movement of the point spread function, that is, the blur trajectory and the trajectory speed as data. In this case, the marker 74 continuously emits light in the order of red, green, and blue at substantially equal intervals (period ta). Therefore, it is possible to know the direction of movement (start point and end point) from the order in which the colors of the trajectory image 100 are arranged. In addition, the motion vector (the direction of motion in which the blur is generated) can be known from the entire trajectory image 100. Furthermore, since the trajectory images 100r, 100g, and 100b of each color are captured with a predetermined exposure time, the red light source 76R and the green light source 76G are derived from the lengths Lr, Lg, and Lb of the trajectory images 100r, 100g, and 100b. The relationship between the relative movement speed v between the camera 20 and the marker 74 when the blue light source 76B is imaged can be known.

  Taking the trajectory image 100 shown in FIG. 4B as an example, the trajectory image 100 is formed in the order of red, green, and blue from the upper left to the lower right (arrow M) in the figure. Therefore, it can be seen that the movement along the arrow M starts from the upper left corner and starts from the lower right corner. Further, the trajectory image 100 has a relationship of the length Lg of the green trajectory image 100g> the length Lr of the red trajectory image 100r> the length Lb of the blue trajectory image 100b. Therefore, the relative movement speed vr between the camera 20 and the marker 74 when the red light source 76R is imaged, the relative movement speed vg between the camera 20 and the marker 74 when the green light source 76G is imaged, and the blue light source 76B. It can be seen that the relationship between the relative movement speed vb between the camera 20 and the marker 74 when the image is taken is: relative movement speed vg> relative movement speed vr> relative movement speed vb.

Next, in the image generation step S15, an unblurred original image is generated from the blurred image B using the point diffusion function calculated in the point diffusion function calculation step S14. This method will be briefly described.
The blur of the image is modeled as the following formula (1). As shown in this equation (1), when the original image is Image, the blurred image is Blur, and the point diffusion function that is a parameter indicating how the image is blurred is PSF, the blurred image (Blur) is point spread. It is given by the convolution operation of the function (PSF) and the original image (Image). As the name suggests, the point spread function (PSF) is a function that expresses how data that is originally one point is spread.

  Here, if the Fourier transform operation for the function f is expressed as F [f] as in the following formulas (2), (3), and (4), the Fourier transform of the original image (Image) is an image, a blurred image. The Fourier transform of (Blur) can be expressed as Blur, and the Fourier transform of the point spread function (PSF) can be expressed as psf. Since the convolution operation is converted into simple multiplication by Fourier transform, Expression (1) is converted to Expression (5) below.

  As shown in the following equation (6), the Fourier transform (image) of the original image is the inverse of (psf) which is the Fourier transform of the point spread function (PSF) and the Fourier transform of the blurred image (Blur) (blur). ) And the product. When the inverse Fourier transform operation of the function f is IF [f], the original image (Image) without blur is the Fourier transform (image) of the original image obtained by Equation (6) as in Equation (7). It is obtained by inverse Fourier transform.

  The arithmetic processing as described above is a simple mathematical process, and an example thereof is a Wiener filter process. In this way, the unblurred original image G shown in FIG. 4C is generated.

  Next, in a workpiece position calculation step S16 shown in FIG. 3, the position of the workpiece W is calculated based on the generated original image G. And the information regarding the calculated position is sent to the robot operation control unit 40 shown in FIG. The robot operation control unit 40 controls the operation of the operation unit such as the arm 17 based on the information. That is, the robot operation control unit 40 calculates the drive amounts of a plurality of actuators for moving the robot 10 based on the information, generates a drive signal for each actuator, and sends the drive signal to each actuator. As a result, the arm 17 moves to a predetermined position, and a predetermined work is performed on the workpiece W by the robot hand 19. A known position calculation method is applied as the method for calculating the position of the workpiece W. For example, the position may be calculated by paying attention to the feature points of the shape of the workpiece W, or the position may be calculated by comparing a separately prepared image for each posture of the workpiece W with the generated original image. Good.

The effects of this example will be described below.
(1) The robot system 5 described above is provided with the markers 74 that emit light in red, green, and blue sequentially on the stage 72 on which the workpiece W is placed. When the position of the workpiece W is detected, the camera 20 provided in the robot 10 captures an image so that the workpiece W and the marker 74 are in the same field of view. When the captured image of the workpiece W is an image including motion blur, a point diffusion function can be obtained from the locus image 100 of the marker 74. That is, the trajectory image 100 is formed in a band shape because the marker 74 emits light continuously. Therefore, it is possible to easily know the motion vector (the motion direction in which the blur is generated) from the belt-like trajectory image 100.

  The marker 74 emits light of a plurality of wavelengths, that is, light of a plurality of colors (for example, red, green, and blue) in a predetermined order. Therefore, the belt-like trajectory image 100 includes a red belt-like trajectory image 100r, a green belt-like trajectory image 100g, and a blue belt-like trajectory image 100b. By observing the configuration of the trajectory images 100r, 100g, and 100b of the respective colors, the constituent elements of the point spread function can be easily acquired. That is, the direction of movement (start point and end point) from the order in which the colors of the trajectory image 100 are arranged, and the relative moving speed between the camera 20 and the marker 74 from the lengths Lr, Lg, Lb of the trajectory images 100r, 100g, 100b of the respective colors. The relationship of v can be easily known.

  Therefore, the point spread function can be easily obtained with high accuracy simply by analyzing the image of the camera 20, and the original image can also be generated with high accuracy. As a result, the position of the workpiece W can be easily detected, and the working efficiency of the robot system 5 can be improved.

(Second embodiment)
Here, the robot system of the second embodiment will be described with reference to FIGS. FIG. 5 is a diagram for explaining the stage of the second embodiment, and FIG. 6 is a diagram showing an image of a workpiece according to the second embodiment. In addition, 2nd Example is an example from which the installation condition of the marker 74 differs with respect to 1st Example. Further, the same configurations and contents as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 5, the stage 72 includes one marker 74a, 74b, and 74c in the vicinity of three corners of the stage surface 72a on which the workpiece W is placed. The markers 74a, 74b, and 74c have the same structure and controlled method as in the first embodiment, and emit light having a plurality of wavelengths. That is, the markers 74a, 74b, and 74c emit light in the order of red, green, and blue at a period ta shown in FIG.

  In the marker & workpiece imaging step S12 of the position detection method shown in FIG. 3, using the camera 20 shown in FIG. 1, the workpiece W and markers 74a, 74b, and 74c placed on the stage 72 are within the same field of view. Take an image. As a result, a so-called blurred image Ba including motion blur shown in FIG. 6 is obtained. The blurred image Ba includes an image Bw of the workpiece W including motion blur, a trajectory image 110 of the marker 74a, a trajectory image 120 of the marker 74b, and a trajectory image 130 of the marker 74c near each of the three corners of the image. .

  The trajectory images 110, 120, and 130 have the same configuration as the trajectory image 100 shown in FIG. Therefore, information on the spatial movement of the point diffusion function can be obtained at each corner of the stage 72. In other words, at three corners, it is possible to know the relationship between the direction of movement (start point and end point), the motion vector (the direction of motion that caused the blur), and the relative movement speed v between the camera 20 and the markers 74a, 74b, and 74c. it can. As a result, the point spread function can be calculated more accurately.

  For example, in the relative movement between the camera 20 and the workpiece W (stage 72), even if blurring occurs due to movement such as rotation or inclination, the point spread function can be more accurately analyzed by analyzing the trajectory images 110, 120, and 130. Can be calculated. Therefore, the position of the workpiece W can be known more accurately from the obtained point spread function, and the work accuracy of the robot 10 can be improved. Note that the number of markers 74 is not limited to one described in the first embodiment and three described in the second embodiment. The number of markers 74 may be determined in accordance with the expected movement of the camera 20 and the workpiece W (stage 72).

  In the present embodiment, it is preferable that the markers 74a, 74b, and 74c emit light of different colors at a specific time point. For example, when the light emission order of the timing chart shown in FIG. 2C is shifted and the marker 74a emits red light, it is preferable that the marker 74b emits green light and the marker 74c emits blue light. By doing in this way, the marker 74 imaged on the blurred image Ba can be specified.

  As mentioned above, although the Example of this invention was described, various deformation | transformation can be added with respect to the said Example in the range which does not deviate from the meaning of this invention. For example, modifications other than the above embodiment are as follows.

  (First Modification) In the above-described embodiment, the case where the marker 74 has one light emitting portion 75 and emits light sequentially in the order of red, green, and blue has been described. However, the present invention is not limited to this. As shown in FIG. 7A, which is a diagram for explaining the first modification, the marker 74d has three light emitting portions 75, a red light emitting portion 75R ′, a green light emitting portion 75G ′, and a blue light emitting portion 75B ′. You may be comprised from. Details of the first modification will be described below. In addition, about the structure and content similar to 1st Example and 2nd Example, a code | symbol is made equal and description is abbreviate | omitted.

  In the first modification, each of the red light emitting unit 75R ′, the green light emitting unit 75G ′, and the blue light emitting unit 75B ′ is configured by, for example, red, green, and blue LEDs (light emitting diodes). ) It is arranged in a row so as to be in close contact with each other in the middle Y direction. The red light emitting unit 75R ′, the green light emitting unit 75G ′, and the blue light emitting unit 75B ′ are controlled by the control signal C shown in FIG. 2C output from the mark generating unit 45 of the control unit 50 shown in FIG. Emits light.

  That is, as shown in the timing chart of FIG. 2C, the red light emitting unit 75R 'starts emitting light at time t0 and continues emitting light until time t1. Next, the green light emitting unit 75G ′ starts emitting at time t1 and continues emitting until time t2. Next, the blue light emitting unit 75B 'starts to emit light at time t2 and continues to emit light until time t3. Thereafter, the red light emitting unit 75R ', the green light emitting unit 75G', and the blue light emitting unit 75B 'repeat this operation. That is, the marker 74d emits light in the order of red, green, and blue at a period ta shown in FIG.

  In the marker & workpiece imaging step S12 of the position detection method shown in FIG. 3, imaging is performed using the camera 20 shown in FIG. 1 so that the workpiece W and the marker 74d placed on the stage 72 are within the same visual field. As a result, a so-called blurred image Bb including motion blur shown in FIG. 7B is obtained. The blurred image Bb includes an image Bw of the work W including motion blur and a trajectory image 140 of the marker 74d. Since the marker 74d emits light in the order of red, green, and blue, the trajectory image 140 includes an individual red belt-like trajectory image 140r, a green belt-like trajectory image 140g, and a blue belt-like trajectory image 140b. It is configured.

  In the point spread function calculation step S14 shown in FIG. 3, the point spread function is calculated by extracting the trajectory image 140 from the blurred image Bb. Even in this case, by analyzing the red trajectory image 140r, the green trajectory image 140g, and the blue trajectory image 140b, the movement direction (start point and end point), the motion vector (the motion direction causing the blur), and The relationship of the relative moving speed v between the camera 20 and the marker 74d can be known.

  That is, in the first modification, the same effects as those of the first and second embodiments can be achieved with a simple structure in which red, green, and blue LEDs are directly arranged on the stage 72. In addition, the arrangement | positioning method of red, green, and blue LED is not limited above, Various modifications are assumed. For example, as shown in FIG. 7C, a red light emitting unit 75R ″, a green light emitting unit 75G ″, and a blue light emitting unit 75B ″ are arranged so as to be at the apex of a triangle, and the marker 74e is arranged. It may be configured.

  (Second Modification) In the above-described embodiment, the marker 74 has the red light source 76R, the green light source 76G, and the blue light source 76B as shown in FIG. It is not limited.

  As shown in FIG. 8, which is a diagram for explaining the second modification, one end of each of optical fibers 87a, 87b, 87c is connected to the markers 74a, 74b, 74c provided near the three corners of the stage surface 72a. ing. One light source 92 is provided on the other end side of the optical fibers 87a, 87b, 87c. In the space between the other end side of the optical fibers 87a, 87b, and 87c and the light source 92, a disk-shaped rotating body 90 is disposed. The rotating body 90 is made of a material that transmits light, and the plane of the disk is colored into three equal parts, and includes a red light transmitting portion 90R, a green light transmitting portion 90G, and a blue light transmitting portion 90B. Yes. The rotating body 90 is configured to rotate in the direction of arrow N in the drawing in response to a driving force of a motor (not shown). The rotational speed of the rotator 90 is controlled by the mark generator 45 shown in FIG.

  With this configuration, the light from the light source 92 passes through one of the red light transmitting portion 90R, the green light transmitting portion 90G, and the blue light transmitting portion 90B of the rotating body 90, and the optical fibers 87a, Released from the markers 74a, 74b, 74c via either 87b, 87c. That is, by controlling the rotation speed of the rotating body 90, the markers 74a, 74b, and 74c can sequentially emit red, green, and blue light at a predetermined cycle.

  (Third Modification) In this embodiment, the case where an articulated robot is employed as the robot 10 has been described. However, the present invention is not limited to this and may be a scalar type robot. The robot 10 may be used for various purposes such as gripping parts by the robot hand 19, performing processing such as soldering and welding. Furthermore, the robot is not limited to an industrial robot, and may be a medical robot or a home robot. In this embodiment, the case where the marker 74 emits red, green, and blue light has been described as an example. However, the present invention is not limited to this. Any color that can be identified is acceptable. Moreover, it is not limited to three colors.

  DESCRIPTION OF SYMBOLS 5 ... Robot system, 10 ... Robot, 19 ... Robot hand, 20 ... Camera, 30 ... Image processing apparatus, 32 ... Image input part, 34 ... Position information acquisition part, 35 ... Point spread function calculation part, 39 ... Position calculation part , 45 ... Mark generating unit, 50 ... Control unit, 60 ... Computer, 72 ... Stage, 74 ... Marker, 75 ... Light emitting unit, B ... Blurred image, W ... Work as work object, S12 ... Marker & work imaging step , S14: Point diffusion function calculation step, S15: Image generation step, S16: Work position calculation step.

Claims (6)

A robot that performs work on a work object;
While placing the work object, a stage provided with a marker that emits light of a plurality of wavelengths,
An imaging device that images the work object and the marker as the same image,
A point spread function calculation unit that extracts a trajectory image of the marker from a deteriorated image including motion blur imaged by the imaging device, and calculates a point spread function from the trajectory image;
An image generation unit that generates an original image that has not deteriorated from the deteriorated image by performing image conversion on the deteriorated image using the calculated point spread function;
And a position calculator that calculates a position of the work object from the generated original image.   The robot system according to claim 1, wherein the marker sequentially emits light of different wavelengths at a specific period.   The robot system according to claim 1, wherein the marker emits light of at least three different wavelengths.   The robot system according to any one of claims 1 to 3, wherein a plurality of the markers are provided on the stage.   The robot system according to claim 1, wherein the plurality of markers emit light having different wavelengths at a certain point in time. A control method of a robot system for performing work on a work object,
An imaging step of imaging the work object placed on a stage including a marker that emits light of a plurality of wavelengths together with the marker by an imaging device;
A point diffusion function calculating step of extracting a locus image of the marker from a deteriorated image including motion blur imaged by the imaging device and calculating a point diffusion function from the locus image;
An image generation step of generating an original image not deteriorated from the deteriorated image by converting the deteriorated image using the calculated point spread function;
And a position calculation step of calculating a position of the work object from the generated original image.

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