JP5418490B2 - POSITIONING CONTROL DEVICE AND POSITIONING DEVICE HAVING THE SAME - Google Patents

Description

  The present invention relates to a positioning control device that controls the position of a stage using an image photographed by a camera, and a positioning device including the same.

  In a positioning apparatus using an XYθ stage that performs parallel movement in the XY direction and rotational movement in the θ direction, or a UVW stage that performs parallel movement in the XY direction and rotational movement in the θ direction, the camera uses an XYθ stage or UVW. An XYθ stage or UVW is used to measure the position of the positioning target by imaging the object to be imaged (positioning target) placed on the stage, and to match the position of the positioning target with a position target value of the positioning target given from the outside. Move the stage. When performing such a positioning operation, in order to reduce the time (task time) required for the positioning operation, it is desirable to photograph the positioning target with the camera while moving the positioning target or the stage without temporarily stopping it. . However, if the position of the positioning target is measured using the image captured by the camera while the positioning target or the stage is moved, and the positioning operation is performed using the measurement result, the positioning accuracy deteriorates.

  In the conventional imaging method, the process of capturing a graphic image on the substrate while relatively moving the substrate on the stage that is driven at high speed and the camera, and the relative relationship between the substrate and the camera when imaging the graphic image on the substrate. Based on the moving speed and moving distance, when the imaging trigger is generated in the state without correction, the deviation amount prediction process between the imaging target position of the board and the actual shooting position, and the predicted deviation amount And an imaging trigger correction step of shifting the timing of generating the imaging trigger by the time to be performed. The shift amount prediction step includes correcting a position of a target to be captured from a reference substrate imaging step of imaging a reference substrate while relatively moving a reference substrate and a camera, and an image captured in the reference substrate imaging step. A measurement step of measuring a deviation amount from an actual imaging position due to an imaging trigger without an image, and a step of predicting a deviation amount based on the measured deviation amount. By providing such a process, it is possible to capture an image on the substrate at an accurate position while relatively moving the substrate and the imaging device (see, for example, Patent Document 1).

  Further, the conventional component mounting apparatus has a mounting head and a shutter camera. When the mounting head moves to a predetermined position, a recognition unit that instructs the shutter camera to start imaging of the component, and a recognition unit The shutter is based on the first distance that the mounting head has moved from the instruction to start imaging to the start of exposure of the shutter camera and the second distance that the mounting head has moved from the instruction to start imaging by the recognition means to the end of exposure of the shutter camera. Correct the position of the component in the image obtained by imaging with the camera, correct the mounting position of the component by the mounting head based on the corrected position of the component, and mount so that the component is mounted at the corrected mounting position And a main control unit for controlling the head. With this configuration, position correction at the time of component mounting can be performed with high accuracy (see, for example, Patent Document 2).

  In the conventional mark recognition device, when the substrate mark and IC mark provided on the substrate are read by a CCD camera provided on the head and driven by an XY drive mechanism, the image is captured while moving at a constant speed to recognize the position. By correcting the difference between the position data acquired during camera movement acquired in advance and the position data acquired during stoppage with the imaging method difference data, the recognition position accuracy is ensured and the mark recognition time is shortened. It is possible to plan.

WO2007 / 129733 JP 2006-287199 A JP 2004-79925 A

  In the conventional imaging method, when the image on the substrate placed on the stage is imaged, the position of the substrate on the stage and the substrate actually photographed based on the relative moving speed and moving distance between the substrate and the camera. The amount of deviation from this position is predicted, and the timing for generating the imaging trigger is shifted by a time corresponding to the predicted amount of deviation. Therefore, it is possible to pick up images on the substrate at accurate positions at various moving speeds and moving distances. However, in order to perform imaging at an accurate position by this method, there has been a problem that the center of the substrate to be imaged must pass through the optical axis of the camera.

  Further, in the conventional component mounting apparatus, based on the first distance that the mounting head has moved from the imaging trigger to the start of exposure of the camera, and the second distance that the mounting head has moved from the imaging trigger to the end of exposure of the camera, The position measurement accuracy of the parts is improved by correcting the position of the parts in the image captured by the camera, but it is necessary to measure the time when the camera starts exposure. When using a normal camera that does not have a problem, there is a problem that it is difficult to realize.

  By the way, in a general-purpose positioning device, a camera and a control unit of a stage on which a positioning target is placed are connected via a network, the position of the positioning target is detected from an image captured by the camera, and the detected position of the positioning target is controlled by the control unit The stage may be controlled so that the position of the positioning target follows the target position value of the positioning target in the control unit. When this configuration is applied to a conventional component mounting apparatus, there is a problem that it is difficult to correct positioning errors caused by network transmission delay.

  In addition, in the conventional mark recognition device, the difference between the position data acquired during the camera movement acquired in advance and the position data acquired during the stop is obtained by capturing the image and recognizing the position while moving at a constant speed when reading by the CCD camera. However, in this method, a delay until the positioning control device 20 recognizes an image after the end of exposure of the camera, for example, an error in recognition position accuracy due to a communication delay of an image capturing end signal cannot be corrected. was there.

  The present invention has been made to solve the above-described problems, and recognizes the time when the positioning target is actually captured by the camera while the positioning target is moving, and the drive control device that moves the positioning target. A positioning control device that enables a highly accurate positioning operation by correcting a difference from the time at which the positioning target is imaged and a positioning device including the same are provided.

  The positioning control device according to the present invention outputs an imaging time specifying signal that can specify the time when the imaging of the positioning target by the camera is completed, and processes the captured image to specify the detection position of the positioning target. The image processing device to output, the imaging time specifying signal, the detection position, and the rotational position of the motor that moves the positioning target are acquired, and a predetermined time before the rotational position at the time when the imaging time specifying signal is acquired And a drive control device for controlling the motor so that the position of the positioning target becomes the target position based on the calculated value, the detection position, and the target position of the positioning target. The positioning target is imaged while the positioning target is stationary, and the drive control device controls the motor so that the position of the positioning target becomes the target position. The first rotation position of the motor in the case where the motor is moved, and the motor when the motor is controlled so that the position of the positioning target becomes the target position by imaging the drive target while moving the positioning target The second rotation position is acquired in advance, and the predetermined time is determined based on the first rotation position and the second rotation position.

  The positioning device according to the present invention includes the positioning control device, a camera that captures an image including a positioning target and outputs the image to the image processing device, a table on which the positioning target is placed, a motor that drives the table, And a stage having a detector for detecting the position of the table.

  According to the present invention, it is possible to obtain a positioning control device that enables highly accurate positioning and a positioning device including the same.

It is a block diagram which shows the positioning device which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the XY (theta) stage which concerns on Embodiment 1 of this invention. It is a flowchart of the positioning operation | movement which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating the relationship between the time in each step of the positioning operation | movement which concerns on Embodiment 1 of this invention, and a motor rotational position. It is explanatory drawing for demonstrating the table position in each step of the positioning operation | movement which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating the calculation procedure of the motor rotation command value which concerns on Embodiment 1 of this invention. It is a flowchart of the operation | movement which determines the correction parameter which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating the relationship between the correction parameter which concerns on Embodiment 1 of this invention, and a positioning error. It is a flowchart of the operation | movement which determines the correction parameter which concerns on Embodiment 2 of this invention. It is explanatory drawing for demonstrating the relationship between the correction parameter which concerns on Embodiment 2 of this invention, and a positioning error. It is a block diagram of the positioning device which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
Hereinafter, the positioning control device 20 using the image processing device 30 and the positioning device 10 including the same according to Embodiment 1 of the present invention will be described with reference to FIGS. In this embodiment, for the sake of simplicity of explanation, it is assumed that an apparatus for placing and transporting a workpiece when the positioning target is a workpiece is an XYθ stage 50 having a table 51 driven by a motor. Give an explanation. However, the positioning control apparatus 20 described in this embodiment does not limit the apparatus for conveying the workpiece to the XYθ stage 50, and the camera while the object to be imaged and the apparatus for conveying the workpiece to be positioned are moving. It can be used in any positioning control device 20 that captures these at 60. Further, the calibration and the work such as the detection of the center of rotation on the table 51 of the stage 50 have been completed, and the work is photographed with the camera 60 while the XYθ stage is stationary. Will be described on the assumption that the positioning operation can be performed with high accuracy. The positioning operation referred to here refers to an operation for matching the position of the workpiece to the designated position target value and the angle of the workpiece to the designated angle target value. If the XYθ stage 50 is stationary and the workpiece 60 is imaged and the positioning operation cannot be performed with high accuracy, the positioning operation can be performed with high accuracy even if the camera 60 images the workpiece while the XYθ stage 50 is operating. It's obvious what you can't do. Therefore, the above premise does not limit the scope of use of this embodiment.

In FIG. 1, a positioning apparatus 10 including a positioning control apparatus 20 according to this embodiment includes an XYθ stage 50 on which a workpiece is placed, a drive control apparatus 40 that drives and controls the XYθ stage 50, and an output from the drive control apparatus 40. A camera 60 for photographing the workpiece based on a photographing trigger to be generated, and an image is generated based on a signal obtained from the camera 60, and the detected position of the workpiece is subjected to image processing and coordinate conversion. and an image processing device 30 for specifying the detected angle θ _{c of the} workpiece, p _cxy = (p _cx , p _cy ). The XYθ stage 50 determines the position of the workpiece based on the X-axis motor current I _x , Y-axis motor current I _y, and θ-axis motor current I _θ input from the drive control device 40 as a position target value p _ref = (p _refx , p _ref ), the angle of the workpiece is made to coincide with the angle target value θ _ref , respectively. The drive control device 40 includes a position target value p _ref and an angle target value θ _ref as position commands acquired from the outside, a detection position p _cxy and a detection angle θ _c input from the image processing device 30, and an _XYθ stage 50. rotational position p _x of X-axis motor that is _input, based on the rotational position p _theta rotational position p _y and theta-axis motor of the Y-axis motor, the position of the workpiece to the position target value p _ref from the angle of the workpiece X-axis motor current I _x , Y-axis motor current I _y , and θ-axis motor current I _θ for making each follow the angle target value θ _ref , and drive the XYθ stage 50. _{Incidentally,} x-coordinate of the _{p refx} the position target value _{p ref,} y coordinates of _{p refy} the position target value _{p ref,} x coordinate of _{p cx} detection position _{p cxy,} the y coordinates of _{p cy} detection position _{p cxy,} respectively Represent. Also, the camera position of the camera _{60 p cam = (p camx,} p camy) _{and, p Camx} the x coordinate of camera position _{p cam, p Camy} represents the y coordinate of camera position _{p cam.}

As shown in FIG. 2, the XYθ stage 50 includes a table 51 on which a workpiece is placed, an X-axis linear motion unit 52 that moves the table 51 in the X-axis direction, and the X-axis linear motion unit 52 is driven by an X-axis motor current I _x. X-axis motor 53 for driving and a X-axis position detector 54 to be output to the X-axis rotation is the angle X-axis detected drive controller the rotational position p _x of the motor 40 of the motor 53, the table 51 Y axis Of the Y-axis linear motion portion 55 that moves in the direction, the Y-axis motor 56 that drives the Y-axis linear motion portion 55 with the Y-axis motor current I _y , and the rotation angle of the Y-axis motor 56. rotational position p _y and Y-axis position detector 57 outputs the detection and drive control device 40, theta-axis motor current I theta axis rotating table 51 about the theta axis by _theta motor 58, rotation of the theta-axis motor 58 Θ axis mode that is an angle And a θ-axis rotation detector 59 that detects the rotation position pθ of the _motor and outputs it to the drive control device 40. These components are fixed on a base 70 such as a surface plate. 2 is a view of the XYθ stage 50 as viewed from above, the θ-axis motor 58 and the θ-axis rotation detector 59 are hidden behind the table and are not shown in FIG.

The image processing device 30 captures an image from a signal input from the camera 60, outputs the captured image obtained to the image processing unit 32, and identifies an imaging time that can identify the time when the imaging is completed after the imaging is completed. An image capturing unit 31 that outputs the signal _St to the drive control device 40, and a pixel value of the workpiece in the captured image is calculated by performing image processing on the captured image input from the image capturing unit 31, and the calculation result the image processing unit 32 for outputting a pixel value p _p of the workpiece, and the pixel value p _p which is input from the image processing unit 32, based on the calibration of the camera 60 are performed in advance, the position and angle of the workpiece And a coordinate conversion value 33 for outputting the calculation result to the drive control device 40 as the workpiece detection position p _cxy and the detection angle θ _c . As the imaging time specifying signal S _t, and the like can be used imaging completion signal or the time taken for the imaging is output to the moment when imaging is completed. In the description of the present invention, “photographing” means that a camera exposes and outputs a signal, and “imaging” means that the image capturing unit 31 constructs a captured image based on the signal.

  The drive control device 40 includes a control unit 41, an X-axis motor drive unit 42, a Y-axis motor drive unit 43, and a θ-axis motor drive unit 44.

The control unit 41 obtains the imaging start position p _s = (p _sx , p _sy ) acquired from the outside, the rotational position p _x of the X-axis motor input from the XYθ stage 50, and the rotational position p _{y of the} Y-axis motor. and based on the rotational position p _theta of theta-axis motor, the rotational position p _x and Y-axis rotational position p _y of the motor of the X-axis motor outputs a photographing trigger to the camera 60 when passing through the imaging start position p _s. Further, the control unit 41 detects the workpiece position target value p _ref and the detection position p _cxy input from the coordinate conversion unit 33, the rotational position p _x of the X-axis motor input from the _XYθ stage 50, and the Y-axis motor. Based on the rotational position _py and the rotational position p _θ of the θ-axis motor, the X-axis motor rotation command value p _ax is _transmitted to the X-axis motor drive unit 42 so that the position of the workpiece follows the position target value p _ref. the Y-axis motor rotation command value p _ay respectively output to the motor driver 43, and theta-axis motor so that the detection angle theta _c to the angle desired value theta _ref is a rotation command value of the work obtained from the outside to follow The rotation command value _paθ is output to the θ-axis motor drive unit 44.

X-axis motor drive unit 42 receives the X-axis motor rotation command value p _ax output from the control unit 41, a rotational position p _x of the X-axis motor which is output from the X-axis position detector 54, the rotational position p _x outputs the X-axis motor current _{I x} of driving the X-axis motor 53 so as to follow the X-axis motor rotation command value _{p ax} to X-axis motor 53. Similarly, Y-axis motor drive unit 43 receives a Y-axis motor rotation command value p _ay output from the control unit 41, a rotational position p _y of the Y-axis motor which is output from the Y-axis position detector 57, and it outputs the Y-axis motor current I _y to the rotational position p _y drives the Y axis motor 56 so as to follow the Y-axis motor rotation command value p _ay in the Y-axis motor 56. Similarly, the theta-axis motor drive unit 44 receives a shaft motor rotation command value p _A.theta. Theta output from the control unit 41, the rotational position p _theta of theta-axis motor which is output from the theta axis rotation detector 59, A θ-axis motor current I _θ that drives the θ-axis motor 58 is output to the θ-axis motor 58 so that the rotational position p _θ follows the θ-axis motor rotation command value _paθ .

  Next, a positioning operation performed by the positioning control device 20 using the image processing device 30 and the positioning device 10 having the same according to Embodiment 1 of the present invention will be described with reference to the flowchart of FIG.

Step S101:
First, the control unit 41 generates a workpiece position target value p _ref and an angle target value θ _ref and an imaging start position p _s . As a method for generating these values, as shown in FIG. 1, a method in which the control unit 41 obtains from the outside, a method in which the value is generated inside the drive control device 40 by a program, or the like can be used. In this case, the imaging start position p _s is in the image obtained when imaging the table 51 with the camera 60 to be described later, may be the work objects appear position is positioned target. Therefore, the imaging start position p _s is not necessarily the camera position p _cam where the camera 60 is disposed.

Step S102:
The control unit 41 sends an X-axis motor rotation command value p to the X-axis motor drive unit 42 so that the table 51 passes through the imaging start position p _s acquired from the outside at a constant speed V = (V _x , V _y ). _ax is output to the Y-axis motor drive unit 43 as a Y-axis motor rotation command value p _ay . In this case, the velocity V when the table 51 passes through the imaging start position p _s, can be set by the control unit 41. Although rotatable speed V _theta also Setting theta axis as it passes through the imaging start position p _s, it is left to rotate the theta-axis in the image pickup start position p _s, not to shorten the positioning operation time Therefore, in this embodiment, it is assumed that V _θ = 0.

Step S103:
X-axis motor drive unit 42, the X-axis motor rotation command value p _ax output from the control unit 41, so that the rotational position p _x of X-axis motor that is input from the X-axis motor position detector 54 to follow, An X-axis motor current I _x is output to the X-axis motor 53 to drive the X-axis motor 53. Similarly, Y-axis motor drive unit 43, the output from the control unit 41 Y-axis motor rotation command value p _ay, the rotational position p _y of the Y-axis motor that is input from the Y-axis motor position detector 57 is to follow In this way, the Y-axis motor 56 is driven by outputting the Y-axis motor current I _y to the Y-axis motor 56. When the X-axis motor 53 and the Y-axis motor 56 are driven, the X-axis linear motion unit 52 and the Y-axis linear motion unit 55 operate, and the table 51 moves in the X-axis direction and the Y-axis direction. The table 51 approaches to the imaging start position p _s.

Step S104:
Control unit 41, the table 51 is moving, the X-axis motor position detector 54 and the Y-axis rotational position of the X-axis motor that is input from the motor position detector 57 p _x and Y-axis rotational position p _y and imaging of the motor The start position p _s = (p _sx , p _sy ) is compared, and it is determined whether or not the table 51 has passed the imaging start position p _s . Then, the table 51 is if passes through the imaging start position _{p s,} perform the following steps (step S105). If table 51 does not pass through the imaging start position p _s, the flow returns to step S103, the table 51 approaches the imaging start position p _s, to pass at a constant speed V, the X-axis motor drive unit 42 The X-axis motor rotation command value p _ax is output to the Y-axis motor drive unit 43 as the Y-axis motor rotation command value p _ay , respectively. If the constant speed V is input as 0 at this time, the control unit 41 sends the X-axis motor rotation command value p _ax to the X-axis motor drive unit 42 so that the table 51 stops at the imaging start position p _s. The Y-axis motor rotation command value _pay is output to the Y-axis motor drive unit 43, respectively.

Step S105:
Control unit 41, when the table 51 is determined to have passed the imaging start position p _s, issues a shooting trigger to the camera 60.

Step S106:
When the camera 60 obtains a photographing trigger from the control unit 41, the camera 60 outputs a signal obtained by photographing the table 51 (or the workpiece to be positioned) to the image capturing unit 31. In the photographing at this time, it is not always necessary that the center of the work to be photographed passes through the optical axis of the camera.

Step S107:
The image capturing unit 31 generates a captured image captured by the camera based on a signal obtained from the camera 60 and outputs the captured image to the image processing unit 32. In this case, the imaging start position p _s because of the positioning target when photographing the table 51 by the camera 60 work is set to a position caught on the image, always the work objects appear in the captured image generated by the image capturing unit 31. That is, in the image processing of the image processing unit 32 in step S108 to be described later, a situation where the measurement of the pixel values p _p of the work fails so that no. Further, image capturing unit 31 outputs an imaging time specifying signal S _t to the control unit 41 after the time of the captured image. Note that in step S108 to be described later, performs image processing based on the image obtained in Step S107, in order to detect a pixel value p _p of the workpiece, the detection position of the workpiece obtained by coordinate converting the pixel value p _p p _cxy is the position of the workpiece at the time when step S107 is executed. As the imaging time specifying signal S _t as described above, can be used as time spent imaging completion signal or the imaging output to the moment when imaging is completed.

Step S108:
The image processing unit 32 identifies the pixel of the workpiece that is reflected in the captured image input from the image capturing unit 31 by image processing, to measure the pixel value p _p of the workpiece. Then, the measured pixel value p _p is output to the coordinate conversion unit 34. In this case the image processing binarization processing using the edge detection, but the difference is such as to identify the work, as long as it can calculate the pixel value p _p may be using any image processing.

Step S109:
Control unit 41 receives the image capturing time specifying signal S _t from the image capturing unit 32, calculates the time when imaging from the imaging time specifying signal S _t is completed, the rotational position p _x and Y-axis of the X-axis motor at that time get the rotational position p _y of the motor, and stores. Thereafter, the value of p _mx rotational position p _x of the stored X-axis motor, and the value p _my rotational position p _y of the stored Y-axis motor are described respectively. Since this process is performed simultaneously with the operation of the image processing unit 32 (step S108), the operations of steps S108 and S109 are described in parallel in the flowchart of FIG. If, if the imaging time specifying signal S _t is the imaging completion signal, it may be stored rotational position p _x and Y-axis rotational position p _y of the motor of the X-axis motor at the moment when the imaging completion signal is acquired. If the imaging time specifying signal _St is the time taken for imaging, the time when the imaging is completed by adding the time taken for imaging from the time when the control unit 41 issues the imaging trigger to the camera 60 in step S105. determined, it may be stored rotational position p _y of the rotational position p _x and the Y-axis motor of the X-axis motor at the time determined.

Step S110:
The coordinate conversion unit 33 calculates the workpiece detection position p _cxy and the detection angle θ _c from the workpiece pixel value p _p input from the image processing unit 32. The detection position p _cxy calculated here is the position of the workpiece as viewed from the vision coordinate system. Then, the coordinate conversion unit 33 outputs the calculated detection position p _cxy and detection angle θ _c to the control unit 41.

Step S111:
The control unit 41 obtains the workpiece detection position p _cxy and the detection angle θ _c from the coordinate conversion unit 33, and detects the workpiece detection position p _cxy , the position target value p _ref , the detection angle θ _c , the angle target value θ _ref , In addition, the X-axis motor rotation command value p _ax and the Y-axis motor rotation command value p _ay are corrected based on the rotation value p _mx of the X-axis motor and the rotation value p _my of the Y-axis motor stored in step S109, and the correction The X-axis motor rotation command value p _ax is output to the X-axis motor drive unit 42, and the modified Y-axis motor rotation command value p _ay is output to the Y-axis motor drive unit 43, respectively.

The method for correcting the X-axis motor rotation command value p _ax and the Y-axis motor rotation command value p _ay performed by the control unit 41 will be described in more detail. The control unit 41 calculates the X-axis and Y-axis motor rotation command value p _a = (p _ax , p _ay ) using equation (1).

ここでＲ_{θｒｅｆ−θｃ}は、位置決め対象のワークをテーブル５１の回転中心周りにθ_ｒｅｆ−θ_ｃだけ回転変換する回転行列であり、撮像画像から取得した前記ワークの検出角度θ_ｃと角度目標値θ_ｒｅｆとの差θ_ｒｅｆ−θ_ｃを用いて

Here, R _θref−θc is a rotation matrix that rotationally transforms the workpiece to be positioned around the rotation center of the table 51 by θ _ref −θ _c , and the detected angle θ _{c of the} workpiece acquired from the captured image and the target angle value using the difference theta _ref - [theta] _c with theta _ref

で計算される。また、Ｍ＝（Ｍ_ｘ、Ｍ_ｙ）はテーブル５１の回転中心とテーブル５１上のモータの回転位置との相対位置、Ｃ＝（Ｃ_ｘ、Ｃ_ｙ）はテーブル５１の回転中心を表しており、これらの値は撮像開始位置ｐ_ｓをカメラ位置ｐ_ｃａｍに一致させ、かつ一定速度Ｖ＝０としてカメラ６０でテーブル５１を撮影した場合、つまりＸ軸モータの回転位置ｐ_ｘおよびＹ軸モータの回転位置ｐ_ｙをカメラ位置ｐ_ｃａｍに一致させ、かつその場でテーブル５１を静止させてカメラ６０でテーブル５１を撮影した場合に得られる撮像画像から計測可能であり、予め求めておく。

Calculated by M = (M _x , M _y ) represents the relative position between the rotation center of the table 51 and the rotation position of the motor on the table 51, and C = (C _x , C _y ) represents the rotation center of the table 51. these values match the imaging start position p _s to the camera position p _cam, and when taken to the table 51 by the camera 60 as a constant speed V = 0, i.e. the X-axis motor position p _x and Y-axis motor the rotational position p _y to match the camera position p _cam, and it can be measured from the captured image obtained when imaging the table 51 by the camera 60 by stationary table 51 in place, determined in advance.

t _p = (t _px , t _py ) is a correction parameter. As shown in FIG. 4, the table 51 (or a workpiece to be positioned) is photographed with the camera 60 while the table 51 is moved, and the image processing apparatus 30. This corrects the positioning error that occurs when processing is performed. Time the positioning error, and time the image capturing unit 32 to obtain a captured image, the control unit 41 receives the image capturing time specifying signal S _t from the image capturing unit 32, an imaging calculated from the image pickup time specifying signal S _t is completed Is caused by the difference between.

  Next, Formula (1) will be described in more detail with reference to FIGS. In order to simplify the description of Expression (1), Expression (1) will be described by dividing it into three parts of Expressions (3), (4), and (5).

ここでｐ_ｗｃａｍ＝（ｐ_{ｗｃａｍｘ}，ｐ_{ｗｃａｍｙ}）は、記憶したＸ軸モータの回転位置ｐ_ｍｘおよびＹ軸モータの回転位置ｐ_ｍｙがカメラ位置ｐ_ｃａｍに一致しているときの位置決め対象のワーク位置に相当する値である。また、ｐ_ｅ＝（ｐ_ｅｘ，ｐ_ｅｙ）は、前記ワークの位置とテーブル５１上のモータの回転位置との相対位置を表している。

Here, p _wcam = (p _wcamx , p _wcamy ) is the work position to be positioned when the stored rotational position p _mx of the X-axis motor and rotational position p _my of the Y-axis motor coincide with the camera position p _cam. Is a value corresponding to. Further, p _e = (p _ex , p _ey ) represents a relative position between the position of the workpiece and the rotational position of the motor on the table 51.

Equation (3) will be described with reference to FIG. Figure 4 is a time in the horizontal axis, and taking a rotational position p _x or rotational position p _y of the Y-axis motor of the X-axis motor to the vertical axis, the rotational position p _x or Y axis of time and X-axis motor in each step it is a diagram for explaining the relationship between the rotational position p _y of the motor. Here, the vertical axis is the rotational position p _mx of X-axis motor, for X-axis motor 53 is driven at a constant speed V _x, the relationship between the rotational position p _x time and X-axis motor becomes linear . Similarly, when the vertical axis and rotational position p _my of the Y-axis motor, for Y-axis motor 56 is driven at a constant velocity V _y, also a linear relationship between the rotational position p _y time and Y-axis motor . In FIG. 4, the time when the image capturing unit 32 generates the captured image in step S107 is t _S107 , the rotational positions of the X-axis and Y-axis motors at that time are p _S107 = (p _S107x , p _S107y ), and step S109. controller 41 time the _{t S109} that imaging which is calculated from the image pickup time specifying signal _{S t} is completed, the X-axis and rotational position of the Y-axis motor of the time _{t S109, p S109 = (p} S109x, p S109y) in = p _ma = (p _mx , p _my ).

Since the time running the steps as described above are different, also different rotational positions p _y of the rotational position p _x and the Y-axis motor of the X-axis motor in each step. That is, since the position of the table 51 are different at each step, the position of the table 51 at the time and position of the table 51 at the time of the captured image, the imaging which is calculated from the image pickup time specifying signal S _t in step S109 has been completed in step S107 Is different. This is schematically shown in FIG. FIG. 5 illustrates the table position in each step, with the horizontal axis representing the X-axis coordinate and the vertical axis representing the Y-axis coordinate. X-axis motor 53 and Y-axis motor 56 in FIG. 5, since the driving the X-axis direct-acting section 52 and the Y-axis direct-acting section 55 respectively at a constant speed V _x and V _y, the trajectory of the table 51 linearly Go into orbit.

_{Therefore, (p mx -V x * t} px, p my -V y * t py) in equation (3) by calculation of the time _{t S109} that imaging control unit 41 has calculated from the image pickup time specifying signal _{S t} is completed By calculating the rotational positions of the X-axis and Y-axis motors at a time before the correction parameters (t _px, t _py ), the X-axis and Y at time t _S107 when the image capturing unit 31 generates the captured image. The estimated value p _S107 ′ = (p _S107x ′, p _S107y ′) of the rotational position of the shaft motor is obtained. Further, the control unit 41 detects the difference between the estimated value (p _mx −V _x * t _px , p _my −V _y * t _py ) and the camera position p _cam = (p _camx , p _cammy ) as the detection position p _cxy. by subtracting from the rotational position _p x of X-axis and Y-axis motor, and calculates the position of the workpiece positioning target when _{p y} is the camera position _p cam _{= the (p camx,} p _camy) coincides with the Yes.

Of course, the rotational position _p x of X-axis and Y-axis motor in the step S107, it is possible to measure the _{p y,} that is, the rotational position p in the X-axis and Y-axis motor at time _{t S107} the control unit 41 captures an image If it is possible to measure _x and _py , it is not necessary to make such an estimation. However, the rotational position of the X-axis and Y-axis motor at time t _S107 of the captured image p _x, to measure the p _y is the moment the captured image from the semiconductor in the interior of the camera 60 or the image capturing unit 31 is completed It is necessary to take out the signal directly. As described above, it is difficult to directly extract a signal at the moment when image capturing is completed from the camera 60 or the semiconductor in the image capturing unit 31. Also, when it is desirable to be able to use various types of cameras and image processing devices, such as general-purpose positioning control devices, it can be used when it is necessary to extract signals directly from the semiconductors inside these devices. Limit the number of cameras and image processing devices, and lose the flexibility of system construction, which is an advantage of a general-purpose positioning control device. Therefore, X-axis and Y-axis motor position p _x at time t _S107 the control unit 41 captures an _image, without measuring the p _y, accurately estimated to scheme is desirable.

Next, equations (4) and (5) will be described with reference to FIG. In FIG. 6, the horizontal axis is the X axis on the vision coordinate, the vertical axis is the Y axis on the vision coordinate, and the intersection is the origin of the vision coordinate system. Also, represents the center of rotation of the table 51 as viewed from the vision coordinate system C, the rotation center C and on the table 51 in the X-axis and Y-axis rotational position p _x of the motor of the table _51, the relative positions of the p _y in M Since the same symbols as those in FIG. 1 represent the same meaning, the description thereof is omitted.

Formula (4) is expressed as follows. First, the relative position between the position of the _workpiece and the center C of the table 51 when the table 51 is rotated so that the detected angle θ _{c of the} workpiece coincides with the angle target value θ _ref is R _θref−. It is calculated by _θc (p _wcam −C). Then, the center of rotation on the table 51 in the X-axis and Y-axis rotational position p _x of the motor of the calculation result table _51, by subtracting from the relative position M with p _y, a detection angle theta _c to the angle desired value theta _ref the rotational position of the X-axis and Y-axis motor on said workpiece position and the table 51 when the matched p _x, calculates the relative position p _e of p _y.

And the equation (5), by subtracting the relative position p _e from the position target value p _ref is calculated by Equation (4), X axis and Y axis when the position of the workpiece coincides with the position target value p _ref rotation value _{p a} of the motor '= _{(p ax'} to calculate _{the, p ay} '). Thus, the rotational position _p x of X-axis and Y-axis motors, _{p y} and _{p ax ', p ay'} position of the workpiece if brought into match coincides with the position target value _{p ref,} enabling accurate positioning Become.

Step S112:
Control unit 41, and a detected angle theta _c inputted from the angle target value theta _ref and the coordinate conversion section 33 of the workpiece obtained from the outside, calculates the difference between the angle desired value theta _ref and the detection angle theta _c, the The result is output to the θ-axis motor drive unit 44 as the θ-axis motor rotation command value _pa θ ′.

Step S113:
In step S112, the X-axis motor drive unit 42, the Y-axis motor drive unit 43, and the θ-axis motor drive unit 44 receive the X-axis rotation command value p _ax and the Y-axis rotation command value p _ay 'that are input from the control unit 41. and theta axis rotation command value p _A.theta. ', and, X-axis motor position p _x input from XYθ stage _50, based on the Y-axis motor position p _y and theta axis motor rotational position p _theta, X-axis rotation command value p _ax, so that Y-axis rotation command value _{p ay} and theta axis rotation command value _{p A.theta.} to the rotational position of the X-axis motor _p x, the rotational position _{p y} and theta axis motor rotational position p _theta of Y-axis motor, respectively follow X axis motor current I _x , Y axis motor current I _y and θ axis motor current I _θ are calculated and output to X axis motor 53, Y axis motor 56 and θ axis motor 58, respectively. Accordingly, X-axis rotation command value p _ax, the rotational position p _x of the X-axis motor _Y-axis rotation command value p _ay and θ-axis rotation command value p _A.theta., The rotation of the rotational position p _y and θ-axis motor of the Y-axis motor position p _theta is, each X-axis motor 53, Y-axis motor 56 and the theta-axis motor 58 so as to follow is driven, the position of the positioning target work matches the position target value p _ref, that positioning is achieved Become. The rotational position p _x of X-axis and Y-axis motors when the positioning operation is _terminated, p _y is, X-axis and Y-axis motor rotation values p _a of when the position of the workpiece coincides with the position target value p _ref Matches' = (p _ax ', p _ay ').

In the above positioning operation, important items for determining the positioning accuracy is a value of the correction parameter t _p. That in order to perform high-precision positioning is necessary to successfully determine the correction parameter t _p. Next, it is positioning operation work of the positioning target is captured by the camera 60 in still (constant velocity V = 0) rotation value p _a of the X-axis and Y-axis motors when the positioning operation when is finished ' If, from the value of the rotation value p _{a 'of} X-axis and Y-axis motors when the positioning operation when the workpiece is subjected to positioning operation by photographing the workpiece by the camera 60 during operation is completed, the correction parameter t _The operation of automatically determining _p to an appropriate value will be described using the flowchart of FIG.

Step S201:
The control unit 41 generates a workpiece position target value p _ref and an angle target value θ _ref . As a method for generating these values, a method in which the control unit 41 acquires from the outside as shown in FIG. 1 or a method in which the value is generated inside the drive control device 40 by a program or the like can be used. These values are always fixed in the operation of the flowchart of FIG.

Step S202:
The imaging start position p _{s is set} to the camera position p _cam, and the positioning device 10 performs a positioning operation with the constant speed V = 0 (that is, the drive control device 40 images the positioning target while stationary and the positioning target 10 Control so that the position becomes the target position). Since the imaging start position p _s is the camera position p _cam and the constant speed V is 0, the table 51 is once imaged by the camera 60 after the table 51 is stopped at the camera position p _cam . Also, since the constant velocity V = 0, be a value any value of the correction parameter t _p, does not affect the positioning operation. Further, the rotational speed _Vθ of the table 51 at the time of imaging is also set to zero.

Step S203:
X-axis and Y-axis motor rotation command values p _x and p _y corresponding to the first rotation position that is the rotation position of the X-axis and Y-axis motors 53 and 6 when the positioning operation executed in the previous step is completed. Is stored in a storage device (not shown) provided in the drive control device 40. The X-axis and Y-axis motor rotation command values stored here are referred to as _pxS203 and _pyS203 , respectively.

Step S204:
Imaging start position _{p s} camera position _{p cam,} the desired value constant velocity V, and the rotational speed V _theta at the time of imaging 0, and the correction parameter _{t p} to a suitable value, the positioning device from the same initial position as in step S202 10 (I.e., the drive control device 40 takes an image of the positioning target while moving and controls the position of the positioning target to be the target position). The value of the correction parameter determined here is described as t _p '= (t _px ', t _py ').

Step S205:
X-axis and Y-axis motor rotation command values p _xS205 and p _yS205 corresponding to the second rotation position that is the rotation position of the X-axis and Y-axis motors 53 and 6 when the positioning operation executed in the previous step is completed. _Are stored in the storage device, and the positioning error Δp _xS205 = p _xS205 -p _xS203 , _ΔpyS205 = _pyS205 between the positioning operation executed in step S202 and the positioning operation executed in step S204, _{respectively.} It calculates the _-p yS203, positioning error _{Δp S205 = (Δp xS205, Δp} yS205) Request.

Step S206:
Based on the positioning errors Δp _xS205 and Δp _yS205 obtained in the previous step _, and the constant velocity V = (V _x , V _y ) and the correction parameter t _p ′ input in the previous step, the optimum value t of the correction parameter _opt = (t _optx , t _opt ) is calculated.

Step S207:
The correction parameter value t _opt calculated in the previous step is input to the control unit 41.

  The calculation performed in the above flow may be performed automatically by a separate calculation device (not shown) provided in the drive control device 40, and the CPU in the control unit 41 without providing the calculation device. Alternatively, each parameter may be output from the positioning device 10 in a timely manner and calculated by an external calculation device.

Next, the determination of the optimum value t _opt of the correction parameter by the operation described in the flowchart of FIG. 7 will be described in more detail with reference to FIGS. As described above, in formula (1), (the stored X-axis motor position p _m - constant speed V * correction parameter t _p) term since, imaging time specifying signal imaging unit 32 captures a picture S time t _S107 and the control unit 41 outputs a _t is a term for correcting the difference between the time t _S109 where imaging was complete was calculated from the image pickup time specifying signal S _t, capturing time image capturing unit 32 captures a picture rotational position _p x of X-axis and Y-axis motor at time _{t S107} outputting a specific signal _{S t,} estimates the _{p y.} X-axis and Y-axis rotational position _{p S107} and the estimated value of the motor at time _{t S107} this time _{(p mx -V x * t px} , p my -V y * t py) error between becomes a positioning error. In this embodiment, during the imaging constant velocity _{V = (V x, V y} ) for moving, as shown in FIG. 8, a linear relationship between the positioning error and correction parameter t _p The inclination is equal to a constant speed V = (V _x , V _y ) passing through the imaging start position p _s . Therefore to calculate the intersection of the above linear and horizontal axis by the calculated value and the value of the correction parameter t _p, to reduce the positioning error, it is possible to highly accurate positioning.

Therefore, in order to calculate the linear equation of the positioning error and the correction parameter _{t p} described above, from step S201~ Step S205 First, the correction parameter _{t p} experimental positioning errors Delta] p _XS205 and Delta] p _YS205 in the case of _{t p} ' Ask. Constant at these values speed _{V = (V x, V y} ) from a straight line equation allows calculation of the positioning error and correction parameter t _p, positioning errors from the calculated linear equation is zero correction parameter t _{opt =} ( t _optx , t _opt )

となる。

It becomes.

Equation (6) and (7) was calculated by the correction parameter _{t opt = (t optx, t} opty) by performing the positioning operation by entering the control unit 41, by moving the table 51 at a constant speed V, the camera Even if the detection position _pcy of the workpiece to be positioned is detected from the captured image obtained by shooting the table 51 at 60, high-precision positioning is possible. That is, highly accurate positioning can be achieved in a short time.

According to the positioning apparatus using the image processing apparatus in this embodiment, by introducing a correction parameter t _p, based on said second rotational position and the first rotational position, the captured image capturing unit 32 is an image and by correcting the difference between the time t _S109 that the imaging control unit 41 and the time t _S107 that output the image completion signal is calculated from the image pickup time specifying signal S _t is completed as the predetermined time, the imaging table 51 by the camera 60 Even when moving at a constant speed V, the rotational positions of the X-axis and Y-axis motors at time t _S107 when the image capturing unit 32 captures an image and outputs an image completion signal can be calculated with high accuracy. It becomes possible to make the position of the workpiece to be positioned coincident with the position target value _pref .

  In addition, in the positioning device using the positioning control device in this embodiment, the camera to be used is not limited, so that it is possible to construct a highly versatile and flexible system.

  Further, in the positioning control device according to this embodiment, the optimum value of the correction parameter is determined when the positioning target workpiece is photographed by the camera 60 and the positioning operation is performed (constant speed V = 0). The position of the first rotation position of the X-axis and Y-axis motors 53 and 56 when the operation is completed and the positioning operation when the workpiece is photographed by the camera 60 and the positioning operation is performed while the workpiece is moving are completed. Since it can be automatically determined from the values of the second rotational positions of the X-axis and Y-axis motors 53 and 56 at the time, the positioning operation can be easily performed with high accuracy and in a short time.

  In addition, by automating all of the flowchart shown in FIG. 7, it becomes possible for a person who does not have specialized knowledge or the like to obtain an optimal correction parameter, and it is possible to easily perform a highly accurate position operation. .

  In this embodiment, the relationship between the positioning error in a specific correction parameter and the speed of the table 51 at the time of imaging using the camera 60 is obtained and the optimum value of the correction parameter is calculated. Another relationship between the error and the speed of the table 51 at the time of imaging using the camera 60 may be obtained, and the optimum value of the correction parameter may be calculated from the obtained other relationship.

  In this embodiment, the case where the XYθ stage 50 is used has been described. However, the imaging position correction method described in this embodiment is not limited to the case where the XYθ stage 50 is used. You may use for the positioning control apparatus using a camera, and the positioning apparatus in general.

In this embodiment, when the camera 60 images a workpiece to be positioned, the rotation speed V _θ in the θ-axis direction has been described as 0. However, the rotation speed V _θ at the time of shooting may not be 0. In this case, by using a detection angle theta _c of the inputted workpiece and the rotation speed V _theta upon photographing the correction parameter t _{p [theta]} from the coordinate conversion unit 33, the detected angle theta _c

と補正し、補正したθ_ｃ’を式（１）に置けるθ_ｃとして考え、計算すればよい。

And the corrected θ _c ′ is considered as θ _c that can be placed in the equation (1) and calculated.

The correction parameter t _pθ is

と求めればよい。ここで、Δｐ_{θＳ２０５}は、ステップＳ２０２で得られる位置決め対象のワークが静止中に撮影した場合の位置決め動作が終了時のθ軸モータ回転指令値と、ステップＳ２０５で得られる前記ワークが動作中に撮影した場合の位置決め動作が終了時のθ軸モータ回転指令値との差、ｔ_ｏｐｔθは、θ軸の最適な補正パラメータ、ｔ_ｐθ’は、ステップＳ２０５で用いた補正パラメータの値である。

You can ask. Here, Δp _θS205 is a θ axis motor rotation command value at the time when the positioning operation is completed when the workpiece to be positioned obtained in step S202 is photographed while stationary, and the workpiece obtained in step S205 is photographed while the workpiece is in operation. The difference from the θ-axis motor rotation command value at the end of the positioning operation in this case, t _optθ is the optimum correction parameter for the θ-axis, and t _pθ ′ is the value of the correction parameter used in step S205.

  As described above, in the positioning control device according to the present invention, the imaging time specifying signal that can specify the time when the imaging of the positioning target by the camera is completed is output, and the detected position of the positioning target is determined by processing the captured image. An image processing device that identifies and outputs the image capturing time specifying signal, the detection position, and a rotational position of a motor that moves the positioning target, and from the rotational position at the time when the imaging time specifying signal is acquired A drive control device that calculates the rotational position before a predetermined time and controls the motor based on the calculated value, the detected position, and the target position of the positioning target so that the position of the positioning target becomes the target position. The positioning target is imaged while still and the position of the positioning target is set to the target position by the drive control device. When the motor is controlled such that the first rotational position of the motor when the motor is controlled and the positioning target are imaged during movement and the position of the positioning target becomes the target position by the drive control device The second rotational position of the motor is acquired in advance, and the predetermined time is determined based on the first rotational position and the second rotational position, so that a highly accurate positioning operation can be performed in a short time. Can be made possible.

Embodiment 2. FIG.
Hereinafter, a positioning control apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS. The difference between this embodiment and the positioning control device 20 of the first embodiment is a method for determining the correction parameter t _opt . In the first embodiment, the values of the first rotation positions of the X-axis and Y-axis motors 53 and 56 when the positioning operation is completed when the workpiece to be positioned is photographed while the workpiece is stationary, and the workpiece operates. Optimum from the values of the second rotational positions of the X-axis and Y-axis motors 53 and 56 at the time when the positioning operation is finished when the camera 60 is photographed, and the speed V when the work is imaged using the camera 60 Do correction parameter t _opt to had been calculated, in this embodiment, increasing the number of experiments in the case where the workpiece is captured using the camera 60 during operation, to calculate the optimum correction parameter t _opt. 9 and 10, elements with the same symbols perform the same operations as in FIGS. Further, the positioning operation in this embodiment is the same as that of the first embodiment in that the flowchart shown in FIG.

Next, the operation for determining the optimum correction parameter t _opt in this embodiment will be described with reference to the flowchart of FIG. The flowchart of FIG. 9 is composed of nine steps in total. Since steps S201 to S205 perform exactly the same operations as steps S201 to S205 in the first embodiment, description thereof is omitted in this embodiment, and description is made from step S206 ′.

Step S206 ′:
The correction parameter is set to a value different from that in (Step S204), the positioning operation is performed with the imaging start position p _s as the camera position p _cam and the constant speed V as the desired value (that is, the positioning target is being moved by the drive control device 40). And control so that the position of the positioning target becomes the target position). The value of the correction parameter determined here is described as t _p ″ = (t _px ″, t _py ″) (≠ t _p ′). The rotational speed V _θ at the time of imaging is also set to zero.

Step S207 ′:
X-axis and Y-axis motor rotation command value p _{xS207 ′} corresponding to another second rotation position that is the rotation position of the X-axis and Y-axis motors 53 and 6 when the positioning operation executed in the previous step is completed. , _{p YS207} calculates the _{= p xS207 '-p} xS203 and _{Δp yS207' = p yS207 '-p} yS203' stores, positioning error Delta] p _XS207 the positioning operation executed in the previous step _'.

Step S208 ′:
The correction parameter t _p ′ input in step S204, the positioning errors Δp _xS205 and Δp _yS205 obtained in step S205, the correction parameter t _p ″ input in step S206 ′, and the positioning error Δp obtained in step S207 ′. _{Based on xS 207 ′} and _{Δpy 207 ′} , an optimal value t _opt of the correction parameter is calculated.

Step S209 ′:
The calculated correction parameter value t _opt is input to the control unit 41.

  The calculation performed in the above flow may be automatically performed by a calculation device (not shown) provided in the drive control device 40 separately, and is performed by the CPU in the control unit 41 without providing the calculation device. Alternatively, each parameter may be output from the positioning device 10 at an appropriate time and calculated externally.

Next, it will be described in further detail with reference to FIG. 10 that the optimum value t _opt of the correction parameter is obtained by the operation described in the flowchart of FIG. As described in the first embodiment, in this embodiment as well, since it moves at a constant speed V = (V _x , V _y ) during imaging, as shown in FIG. relationship of the straight line between the t _p. Therefore to calculate the intersection of the above linear and horizontal axis by the calculated value and the value of the correction parameter t _p, and further reduce the positioning error, it is possible to more accurate positioning.

Therefore, in order to calculate the linear equation with the correction parameter _{t p} the previous positioning error, first correction parameter _{t p} from step S201~ step S205 is determined experimentally positioning error Delta] p _XS205 and Delta] p _YS205 in the case of _{t p} ' . Further, positioning errors Δp _{xS207 ′} and Δp _{yS207 ′} in a certain correction parameter t _p ″ are obtained from step S206 ′ and step S207 ′. From these values, a linear expression between the positioning error and the correction parameter t _p can be calculated. When a correction parameter t _opt = (t _xopt , t _yopt ) is calculated from the calculated linear equation so that the positioning error is zero.

となる。

It becomes.

Equation (10), is moved calculated correction parameter _{t opt = (t xopt, t} yopt) by performing the positioning operation by entering the control unit 41, the table 51 at a constant speed V by (11), a camera Even if the detection position _{pc xy} of the workpiece to be positioned is detected from the _picked- up image _picked up by using the table 51 at 50, positioning with higher accuracy becomes possible. That is, positioning with higher accuracy is possible in a short time.

According to the positioning control apparatus using the image processing apparatus in this embodiment, the positioning operation for photographing with the camera 60 while the workpiece to be positioned is stationary is performed once, and the positioning operation for photographing with the camera 60 while the workpiece is operating. the by performing 2 times, correction for the optimum value of the parameter t _p can be automatically determined, it is possible to easily perform higher precision and short-time locating operation.

  In addition, by increasing the number of positioning operations that are performed by the camera 60 while the workpiece to be positioned is in operation, it is possible to further reduce the influence of variations in the imaging and positioning operations.

  In addition, in the positioning device using the positioning control device in this embodiment, the camera to be used is not limited, so that it is possible to construct a highly versatile and flexible system.

In this embodiment, the positioning parameter for capturing with the camera 60 while the workpiece to be positioned is stationary is performed once, and the positioning operation for capturing with the camera 60 is performed twice while the workpiece is in motion. Although the relationship with the positioning error is obtained, a positioning operation is performed in which the camera 60 performs imaging while the workpiece is operating according to various correction parameters, and the correction parameter and the positioning are determined by the least square method using the obtained positioning error. The relationship with the error may be obtained, and the optimum value t _opt of the correction parameter may be calculated from the obtained relationship. In this way, it is possible to further reduce the influence of errors due to data variations and the like by increasing the number of positioning operations to be taken by the camera 60 while the workpiece is in operation.

In this embodiment, the rotation speed V _θ in the θ-axis direction is set to 0 when the camera 60 captures the workpiece to be positioned. However, the rotation speed V _θ at the time of shooting need not be 0. . In this case, the rotational speed at the time of shooting and the work detection angle theta _c input from the coordinate conversion unit 33 V _theta, using the correction parameter t _{p [theta],} the detected angle theta _c

と補正し、補正したθ_ｃ’を式（１）に置けるθ_ｃとして考え、計算すればよい。

And the corrected θ _c ′ is considered as θ _c that can be placed in the equation (1) and calculated.

The correction parameter t _pθ is

と求めればよい。ここで、Δｐ_{θ２０７’}は、ステップＳ２０２で得られる前記ワークが静止中に撮影した場合の位置決め動作が終了時のθ軸モータ回転指令値とステップＳ２０７’で得られる前記ワークが動作中に撮影した場合の位置決め動作が終了時のθ軸モータ回転指令値との差であり、ｔ_ｐθ”は、ステップＳ２０７’で用いた補正パラメータの値である。

You can ask. Here, Δp _{θ207 ′} is taken while the workpiece obtained in step S202 is in motion and the θ-axis motor rotation command value at the end of positioning operation and the workpiece obtained in step S207 ′ is taken during operation. In this case, the difference from the θ-axis motor rotation command value at the end of the positioning operation is _tpθ ″ is the value of the correction parameter used in step S207 ′.

  As described above, in the positioning control device 20 according to the present invention, the positioning target is imaged while moving and the operation for controlling the position of the positioning target to be the target position is performed a plurality of times, thereby positioning for each operation. Since a plurality of sets of errors and correction parameters are acquired in advance and the predetermined time is determined based on the plurality of sets, it is possible to easily perform a positioning operation with higher accuracy and in a shorter time.

Embodiment 3 FIG.
A positioning control device 20 according to Embodiment 3 of the present invention will be described below. The difference between this embodiment and the positioning control device of the first and second embodiments is that the positioning control device of the first and second embodiments controls both the position and posture of the workpiece to be positioned. The positioning control device in this embodiment is to control only the position of the workpiece.

In the operation of the positioning control device 20 in this embodiment, the operation of the θ-axis motor 58 is stopped in the operation of the positioning control device 20 in the first or second embodiment, and the rotation matrix R _θref−θc in the equation (1) is Since it is only necessary to use a unit matrix, detailed description is omitted.

  When the workpiece is a circular object or the like, it is only necessary to control the position of the workpiece, and it may not be necessary to control the posture. In this case, it is not necessary to operate the θ-axis motor 58, and by stopping the operation of the θ-axis motor drive unit 44, useless energy is not used, and the calculation related to the θ axis is stopped in the control unit 41. This leads to a reduction in calculation load.

Embodiment 4 FIG.
The positioning device according to Embodiment 4 of the present invention will be described below. In this embodiment, as shown in FIG. 11, the positioning device 10 has a sequence control device 80. Since other than this is the same as in the first or second embodiment, the description is omitted. The sequence control unit 80 is a sequence for performing the operation of acquiring the first rotation position and the second rotation position described above to the drive control device 40 (more specifically, the control unit 41) of the positioning control device 20. Is given. That is, the drive control device 40 performs an operation of acquiring the first rotation position and the second rotation position based on a command from the sequence control device 80 that is a means for controlling the sequence in advance.

  By configuring in this way, since all the procedures shown in the flowchart of FIG. 7 or FIG. 9 can be automated, it becomes possible even for those who do not have specialized knowledge, etc. It becomes possible to easily perform a highly accurate position operation.

  DESCRIPTION OF SYMBOLS 10 Positioning device, 20 Positioning control device, 30 Image processing device, 31 Image pick-up part, 32 Image processing part, 33 Coordinate conversion part, 40 Drive control device, 41 Control part, 42 X-axis motor drive part, 43 Y-axis motor drive Unit, 44 θ-axis motor control unit, 50 XYθ stage, 51 table, 52 X-axis linear motion unit, 53 X-axis motor, 54 X-axis position detector, 55 Y-axis linear motion unit, 56 Y-axis motor, 57 Y-axis Position detector, 58 θ-axis motor, 59 θ-axis rotation detector, 60 cameras, 70 pedestal, 80 sequence control device.

Claims (6)

An image processing apparatus that outputs an imaging time specifying signal that can specify the time when the imaging of the positioning target by the camera is completed, and that processes the captured image to specify and output the detection position of the positioning target, and the imaging A time specifying signal, the detection position, and a rotational position of a motor that moves the positioning target are acquired, and the rotational position a predetermined time before the rotational position at the time when the imaging time specifying signal is acquired is calculated, A drive control device that controls the motor based on the calculated value, the detection position, and the target position of the positioning target so that the position of the positioning target becomes the target position;
A first rotational position of the motor when the motor is controlled by the drive control device so that the positioning target is imaged while the positioning target is stationary and the position of the positioning target becomes the target position, and the positioning target is moved A second rotational position of the motor when the motor is controlled so that the position of the positioning target becomes the target position by the drive control device, and the predetermined time is determined as the first time. A positioning control device, wherein the positioning control device is determined based on a first rotational position and the second rotational position. The positioning error is obtained from the difference between the second rotational position and the first rotational position, and a correction parameter that minimizes the positioning error is determined from the information regarding the positioning error and the moving speed of the positioning target. The positioning control apparatus according to 1. A plurality of sets of positioning errors and correction parameters for each operation are acquired in advance by performing an operation for imaging the positioning target while moving and controlling the position of the positioning target to be the target position a plurality of times. The positioning control device according to claim 2, wherein the predetermined time is determined based on the plurality of sets. A stage having a table on which a positioning target is placed, a motor that drives the table, and a detector that detects a table angle of the table;
The drive control device is configured such that the positioning target is input from outside or generated internally based on the table angle detected by the detector and the angle of the positioning target detected by the image processing device. The positioning control apparatus according to claim 1, wherein the table angle is controlled so as to be an angle target value of a positioning target. The drive control device performs an operation of acquiring a first rotation position and a second rotation position based on a command from a means for controlling a sequence in advance. Positioning control device. The positioning control device according to any one of claims 1 to 5,
A camera that captures an image including a positioning target and outputs the image to an image processing apparatus;
And the positioning apparatus provided with the stage which has the table which mounts the said positioning object, the motor which drives this table, and the detector which detects the position of the said table.

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