Positioning device

Abstract

To accurately perform positioning in a short time.SOLUTION: This positioning device is provided with a moving mechanism 1 for moving a target P, a camera 2 provided in the moving mechanism 1, an image processing part 3 for outputting position information D1 of the target P based on image information D2 imaged by the camera 2, and a control part 4 for controlling the moving mechanism 1 so as to move the target P to a target point based on the position information D2. The control unit 4 outputs the synchronizing signal S1 at a constant cycle, and the camera 2 and the image processing unit 3 operate in response to the synchronizing signal S1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a positioning device that positions a moving body at a target position. [Background technology]

[0002] Positioning devices for moving objects have been used in industrial machinery such as electronic equipment manufacturing equipment and various processing devices. For example, a component mounting device that produces electronic boards by mounting electronic components in predetermined positions on a printed circuit board is known as such a positioning device.

[0003] In a typical positioning device, a camera captures an image of a moving object, and an image processing unit outputs position information of the moving object based on the image data from the camera. If the moving object moves even during processing by the image processing unit, the control unit must estimate the current position of the moving object from the position information of the moving object.

[0004] For example, the moving body position measuring device of Patent Document 1 includes a measurement circuit that measures the time difference between the input of an imaging signal from a controller and the input of a vertical synchronization signal from an image processing device, and a controller (control unit) that determines the position of the moving body from the determined time difference, the moving speed of the moving body, and the image processing signal from the image processing device.

[0005] In addition, the positioning device of Patent Document 2 has a main body control unit (control unit) that includes a prediction processing unit that calculates the position of a target object of a moving body, a correction processing unit that corrects the position of the target object, and a processing unit that estimates the current position of the target object. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-239019 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-213139 Summary of the Invention [Problem to be solved by the invention]

[0007] However, Patent Document 1 is based on the premise that the moving object moves at a constant speed, and therefore can only be applied to such cases. Furthermore, Patent Document 2 requires a complex configuration for estimating the position of the moving object, which limits the positioning accuracy.

[0008] The present disclosure provides a positioning device with improved positioning accuracy. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the positioning device of the present disclosure comprises a moving mechanism for moving a target object, a camera provided on the moving mechanism, an image processing unit for outputting position information of the target object based on an image captured by the camera, and a control unit for controlling the moving mechanism to move the target object to a target location based on the position information, wherein the control unit outputs a synchronization signal at a constant period, and the camera and the image processing unit operate in accordance with the synchronization signal. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to improve positioning accuracy while reducing delay time. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic configuration diagram showing the configuration of a positioning device according to an embodiment. [Figure 2] 5A and 5B are diagrams showing an example of output timing of signals output from each unit of the positioning device according to the embodiment. [Figure 3] FIG. 10 is a diagram showing an example of output timing of signals output from each unit of a positioning device according to a conventional example. [Figure 4] 10A to 10C are diagrams showing other examples of output timings of signals output from the respective units of the positioning device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0013] (Configuration of positioning device) Fig. 1 is a schematic diagram showing the configuration of a positioning device according to this embodiment. As shown in Fig. 1, the positioning device according to this embodiment includes a moving mechanism 1, a camera 2, an image processing unit 3, and a control unit 4. In the following description, the height direction is defined as the Z direction, and directions perpendicular to the Z direction are defined as the X direction and the Y direction.

[0014] The moving mechanism 1 is a moving mechanism that moves a target P in the X and Y directions. The target P is, for example, an electronic component or an alignment mark. In FIG. 1, the target P is shown as a cross mark, but the target P may have any shape.

[0015] The moving mechanism 1 includes a stage 11 and motors 12 and 13 .

[0016] The stage 11 is a stage on which the target P is placed. The stage 11 extends in the X and Y directions and is formed in a substantially planar shape. A motor 12 is attached to the end of the stage 11 in the X direction, and a motor 13 is attached to the end of the stage 11 in the Y direction. The target P placed on the stage 11 moves in the X and Y directions on the stage 11 by driving the motors 12 and 13. As will be described in detail later, the motors 12 and 13 are driven based on a control signal S3 output from the control unit 4.

[0017] Camera 2 captures an image of target P placed on stage 11. Specifically, camera 2 is placed above stage 11 (in the Z direction) and is installed so that the imaging direction faces the stage. Camera 2 captures an image in response to an imaging signal S2 output from timing generation unit 31 of image processing unit 3. Camera 2 then outputs the captured image data D1 (image) to position information generation unit 32 of image processing unit 3.

[0018] The image processing unit 3 is, for example, a computer, etc. The image processing unit 3 communicates with the camera 2 and the control unit 4. The image processing unit 3 also includes a timing generation unit 31 and a position information generation unit 32.

[0019] The timing generation unit 31 receives a synchronization signal S1 output from the control unit 4 and outputs an imaging signal S2 to the camera 2. Specifically, the timing generation unit 31 outputs the imaging signal S2 to the camera 2 when it receives the synchronization signal S1 a predetermined number of times (three times in this embodiment) from the control unit 4. In other words, the timing generation unit 31 outputs the imaging signal S2 to the camera 2 every time it receives the synchronization signal S1 a predetermined number of times.

[0020] The position information generation unit 32 generates position information D2 of the target P based on the image data D1 output from the camera 2. For example, the position information generation unit 32 extracts an image of the target P from the received image data D1 to generate position information D2 indicating the position of the target P on the stage 11. The position information generation unit 32 outputs the generated position information D2 to the control unit 4.

[0021] The control unit 4 is, for example, a computer, etc. The control unit 4 controls each part of the positioning device.

[0022] Specifically, the control unit 4 generates a synchronization signal S1 at predetermined intervals and outputs it to the image processing unit 3 (timing generation unit 31). That is, the control unit 4 outputs the synchronization signal S1 to the image processing unit 3 at a constant cycle. As described above, the timing generation unit 31 outputs an imaging signal S2 to the camera 2 every time it receives the synchronization signal S1 a predetermined number of times. Therefore, the camera 2 and the timing generation unit 31 (image processing unit 3) operate at a cycle that is an integer multiple of the cycle at which the synchronization signal S1 is output.

[0023] Furthermore, the control unit 4 receives position information D2 output from the image processing unit 3 (position information generating unit 32) and drives the motors 12 and 13. Specifically, the control unit 4 identifies the position of the target object P based on the received position information D2, and outputs a control signal S3 to the motors 12 and 13 to control the driving of the motors 12 and 13 so as to move the position of the target object P to the target point. The motors 12 and 13 are driven based on the received control signal S3. Here, the control unit 4 outputs the control signal S3 to the motors 12 and 13 at a constant period. Specifically, the control unit 4 outputs the control signal S3 to the motors 12 and 13 at the same timing as the synchronization signal S1.

[0024] (Regarding signal output timing) Fig. 2 is a diagram showing an example of the output timing of signals output from each unit of the positioning device according to this embodiment. Specifically, Fig. 2 shows the output timing of a synchronization signal S1, an imaging signal S2, image data D1, position information D2, and a control signal S3 with arrows.

[0025] 2, the control unit 4 outputs a synchronization signal S1 to the timing generation unit 31 for each period L1 from time T1 to T7. The control unit 4 also outputs a control signal S3 to the motors 12, 13 for each period L1 from time T1 to T7. That is, the control unit 4 outputs the synchronization signal S1 and the control signal S3 at a constant cycle (period L1) and at the same timing. That is, the control unit 4 outputs the synchronization signal S1 and the control signal S3 so that they are synchronized.

[0026] The timing generation unit 31 outputs the imaging signal S2 to the camera 2 at times T1, T4, and T7. That is, the timing generation unit 31 outputs the imaging signal S2 to the camera 2 every time it receives the synchronization signal S1, for example, three times.

[0027] At times T11 and T41, camera 2 outputs image data D1 to position information generator 32. In this embodiment, camera 2 requires, for example, a period L2, which is approximately half the period L1, to output image data D1 after receiving imaging signal S2. That is, in this embodiment, the processing time of camera 2 is period L2.

[0028] The position information generation unit 32 outputs the position information D2 to the control unit 4 at times T31 and T61. The time T31 (T61) is the time that has elapsed since the time T3 (T6), for example, about half the period L1. In this embodiment, the position information generation unit 32 requires the period L3 (for example, about twice the period L1) from receiving the image data D1 to outputting the position information D2. That is, in this embodiment, the processing time of the position information generation unit 32 is the period L3.

[0029] Thereafter, the control unit 4 outputs a control signal S3 based on the received position information D2 to the motors 12 and 13. In this embodiment, upon receiving the position information D2, the control unit 4 outputs a control signal S3 based on the position information D2 at the timing of outputting the next control signal S3.

[0030] According to the above configuration, in this embodiment, positioning is performed using actual position information of the target P without estimating the current position of the target P, so that it is possible to improve positioning accuracy.

[0031] Here, when the delay time is defined as the time from when camera 2 starts capturing images until motors 12 and 13 receive control signals, delay time A1, which is the delay time in this embodiment, is the time from when camera 2 receives image signal S2 (when camera 2 starts capturing images) until motors 12 and 13 receive control signal S3. Specifically, as shown in FIG. 2 , delay time A1 is the sum of period L2, which is the time from when camera 2 receives image signal S2 until it outputs image data D1 (processing time of camera 2), period L3, which is the time from when position information generator 32 receives image data D1 until it outputs position information D2 (processing time of position information generator 32), and period L4, which is the time from when control unit 4 receives position information D2 until it outputs control signal S3. That is, in this embodiment, delay time A1 is period L2 + period L3 + period L4.

[0032] As described above, in this embodiment, the control unit 4 outputs the synchronization signal S1 and the control signal S3 so that they are synchronized. Therefore, if the period L2, which is the processing time of the camera 2, and the period L3, which is the processing time of the position information generator 32, are approximately constant, the period L4, which is the time from when the control unit 4 receives the position information D2 to when it outputs the control signal S3, is also approximately constant. As a result, the delay time A1 is constant.

[0033] FIG. 3 shows an example of the output timing of signals output from each unit of a conventional positioning device. In the conventional positioning device, the control unit 4 and the camera 2 are driven independently, so the timing when the camera 2 starts capturing images and the timing when the control unit 4 controls the motors 12 and 13 are not synchronized. Therefore, as shown in FIG. 3, the control unit 4 outputs a control signal S3 to the motors 12 and 13 at a constant period (period T1), but the control unit 4 does not output a synchronization signal S1 to the timing generator 31 at a constant period. Therefore, the timing when the camera 2 receives the image signal S2 (the timing when the camera 2 starts capturing images) is not constant relative to the timing when the control unit 4 outputs the control signal S3 to the motors 12 and 13. As a result, the period from when the control unit 4 receives the position information D2 to when it outputs the control signal S3 (see periods L4a and L4b in FIG. 3) varies, resulting in variations in the delay time (see delay times A2 and A3 in FIG. 3). Therefore, the conventional positioning device was unable to improve the positioning accuracy or the speed of the moving mechanism.

[0034] In contrast to this, in this embodiment, the control unit 4 outputs the synchronization signal S1 and the control signal S3 so that they are synchronized, so that the delay time A1 is constant, and it is possible to improve the positioning accuracy and the speed of the moving mechanism.

[0035] (Other embodiments) As described above, the embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can be applied to embodiments in which appropriate modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the above embodiments to create new embodiments.

[0036] FIG. 4 is a diagram showing another example of the output timing of signals output from each unit of the positioning device according to this embodiment. In FIG. 4, the timing generation unit 31 outputs the imaging signal S2 a predetermined period after receiving the synchronization signal S1. Specifically, the timing generation unit 31 outputs the imaging signal S2 to the camera 2 at time T12 (T41), which is a period L5 after receiving the synchronization signal S1 at time T1 (T4). Period L5 is approximately the same as period L4 in FIG. 2. In this configuration, the timing at which the control unit 4 receives the position information D2 from the position information generation unit 32 coincides with the timing at which the control unit 4 outputs the control signal S3 to the motors 12 and 13. Therefore, the delay time A4 becomes period L2 + period L3, thereby shortening the delay time.

[0037] In the above embodiment, the moving mechanism may be configured to include a robot arm or the like instead of the stage 11, and the camera 2 may be attached to the robot arm, so that the camera 2 moves together with the robot arm to capture the target P. [Industrial Applicability]

[0038] The positioning device of the present disclosure is useful because it can perform positioning with high accuracy in a short time. [Explanation of symbols]

[0039] 1 Moving mechanism 11 Stages 2 Cameras 3 Image processing section 31 Timing generation unit 32 Location information generation section 4. Control Unit P target

Claims

1. a movement mechanism for moving the target; a camera provided on the moving mechanism; an image processing unit that outputs position information of the target based on the image captured by the camera; a control unit that controls the movement mechanism based on the position information so as to move the target object to a target location, the control unit outputs a synchronization signal at a constant cycle; The positioning device is characterized in that the camera and the image processing unit operate in response to the synchronization signal.

2. 2. The positioning device according to claim 1, wherein the camera and the image processing unit operate after a predetermined time has elapsed from the timing at which the synchronization signal is output.

3. 2. The positioning device according to claim 1, wherein the camera and the image processing unit operate at a cycle that is an integral multiple of the cycle at which the synchronization signal is output.

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