Location teaching device and location teaching method

Abstract

The present invention provides a position teaching device suitable for efficiently teaching the position of the hand unit of a transport robot relative to the destination. [Solution] A position teaching device for teaching the position of a hand unit 4 relative to a transport destination 94, comprising: a first marker 83 provided on the transport destination 94 and located at a first predetermined position relative to a first reference position P1; a second marker provided on the hand unit 4 and located at a second predetermined position relative to a second reference position P2; a camera 5 positioned above the transport destination 94 and photographing the first marker 83 and the second marker; and a teaching unit 63 that calculates the teaching position of the hand unit 4 from the image captured by the camera 5. The teaching unit 63 calculates the coordinates of the first reference position P1 based on the coordinates of the first marker 83 in the image, and calculates the coordinates of the second reference position P2 based on the coordinates of the second marker in the image, and calculates the teaching position of the hand unit 4 based on the coordinates of the first reference position P1 and the coordinates of the second reference position P2.

Description

Technical Field

[0001] The present disclosure relates to a position teaching device and a position teaching method.

Background Art

[0002] In a manufacturing process such as a semiconductor substrate or a liquid crystal substrate, a workpiece such as a semiconductor substrate is transported to a transport destination such as a process device or an inspection device, and a process treatment or an inspection treatment is performed on the workpiece. For the transportation of the workpiece to such a transport destination, a transport robot is used. In the transportation of the workpiece to the transport destination, it is necessary for an operator to teach the transport position to the transport robot in advance by a teaching operation.

[0003] This teaching operation is performed, for example, visually by an operator from the outside through a viewport provided in the transport destination (such as a process device). In the teaching operation of the transport robot, the hand portion that supports the workpiece is moved to the transport destination, and the teaching position is confirmed visually. Therefore, it is necessary for the operator to manually operate and teach the transport robot, and the teaching operation takes time. There is also a problem that the accuracy of the teaching varies depending on the skill level of the operator.

[0004] Patent Document 1 describes a position teaching device that uses a camera mounted on the hand portion (a wrist portion supporting the holding portion) to photograph multiple detection points of a position teaching jig installed at the transport destination, and teaches the position of the hand portion based on the coordinates of the multiple detection points in the image data captured by the camera. In the position teaching device described in the same document, the position teaching jig is installed on a stage at the transport destination (e.g., a load port) and comprises a base plate placed on positioning pins on the stage, and a plurality of marker posts erected on the base plate. Detection points are provided on the marker posts. Position teaching of the hand portion is performed by moving the hand portion of the transport robot onto the stage, photographing multiple detection points with a camera mounted on the hand portion, and using the image data captured by the camera. With such a configuration, manual teaching by an operator is unnecessary, and the time required for teaching can be reduced. However, in the above conventional configuration, it is necessary to accurately position and install the position teaching jig on the transport destination stage. Furthermore, if the destination for which the hand unit's position teaching is to be performed is a process machine or the like, it may not be possible to install the position teaching jig (composed of a base plate and multiple marker posts erected on the base plate) on the stage of the destination. Therefore, it was difficult to perform the teaching work efficiently with the position teaching device described in Patent Document 1. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-58215 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] This disclosure was conceived under these circumstances, and its primary objective is to provide a position teaching device suitable for efficiently teaching the position of the hand portion of a transport robot relative to the transport destination. [Means for solving the problem]

[0007] To address the above challenges, this disclosure employs the following technical measures.

[0008] A position teaching device provided by a first aspect of this disclosure comprises a horizontal articulated horizontal arm mechanism and a hand portion supported by the horizontal arm mechanism for supporting a workpiece, and teaches the position of the hand portion relative to a transport robot that transports the workpiece to a transport destination, the position teaching device comprising: a first marker provided at the transport destination and located at a first predetermined position relative to a first reference position; a second marker provided on the hand portion and located at a second predetermined position relative to a second reference position; a camera positioned above the transport destination and photographing the first marker and the second marker; and a teaching unit that calculates the teaching position of the hand portion from an image captured by the camera, wherein the teaching unit calculates the coordinates of the first reference position based on the coordinates of the first marker in the image, calculates the coordinates of the second reference position based on the coordinates of the second marker in the image, and calculates the teaching position of the hand portion based on the coordinates of the first reference position and the coordinates of the second reference position.

[0009] In a preferred embodiment, the image includes a first image in which the first marker is captured and a second image in which the second marker is captured, and the teaching unit calculates the coordinates of the first reference position based on the coordinates of the first marker in the first image and calculates the coordinates of the second reference position based on the coordinates of the second marker in the second image.

[0010] In a preferred embodiment, the system comprises three or more preceding first markers that are spaced apart from each other in a plan view, and three or more preceding second markers that are spaced apart from each other in a plan view.

[0011] A position teaching method provided by a second aspect of this disclosure is a method for teaching the position of the hand portion relative to a transport robot that transports a workpiece to a transport destination, the transport robot comprising a horizontal articulated horizontal arm mechanism and a hand portion supported by the horizontal arm mechanism for supporting a workpiece, wherein the transport destination is provided with a first marker at a first predetermined position relative to a first reference position, and the hand portion is provided with a second marker at a second predetermined position relative to a second reference position, and the method includes the steps of photographing the first marker and the second marker with a camera positioned above the transport destination, and calculating the teaching position of the hand portion from the image taken by the camera, wherein the step of calculating the teaching position of the hand portion involves calculating the coordinates of the first reference position based on the coordinates of the first marker in the image, calculating the coordinates of the second reference position based on the coordinates of the second marker in the image, and calculating the teaching position of the hand portion based on the coordinates of the first reference position and the coordinates of the second reference position.

[0012] In a preferred embodiment, the image includes a first image in which the first marker is captured and a second image in which the second marker is captured, and in the step of calculating the teaching position of the hand portion, the coordinates of the first reference position are calculated based on the coordinates of the first marker in the first image, and the coordinates of the second reference position are calculated based on the coordinates of the second marker in the second image.

[0013] In a preferred embodiment, the transport destination is provided with three or more first markers that are spaced apart from each other in a plan view, and the hand portion is provided with three or more second markers that are spaced apart from each other in a plan view. [Effects of the Invention]

[0014] The position teaching device described herein makes it possible to efficiently teach the position of the hand unit relative to the transport destination.

[0015] Other features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0016] [Figure 1] It is a plan view showing an example of a work conveyance system to which a position teaching device according to the present disclosure is applied. [Figure 2] It is a schematic side view showing an example of a conveyance robot. [Figure 3] It is a schematic plan view showing an example of the arrangement of the first marker at the conveyance destination. [Figure 4] It is a schematic side view showing an example of the arrangement of the camera and the first marker at the conveyance destination. [Figure 5] It is a plan view showing an example of the arrangement of the second marker in the hand part. [Figure 6] It is a schematic side view showing the teaching position of the hand part at the conveyance destination. [Figure 7] It is a block diagram showing the control of the conveyance robot. [Figure 8] It is a view showing an image of the first marker (first image) taken by the camera. [Figure 9] It is a view showing an image of the second marker taken by the camera when the hand part is at the target position. [Figure 10] It is a flowchart for explaining the teaching process. [Figure 11] It is a view showing an image of the second marker (second image) taken by the camera. [Figure 12] It is a plan view showing another example of the arrangement of the second marker in the hand part. [Figure 13] It is a view showing another example of an image of the first marker (first image) taken by the camera.

Modes for Carrying Out the Invention

[0017] Hereinafter, preferred embodiments of the present disclosure will be specifically described with reference to the drawings.

[0018] The terms "First," "Second," etc., used in this disclosure are merely labels and are not necessarily intended to assign a permutation to the objects.

[0019] Figure 1 is a plan view showing an example of a workpiece transport system to which the position teaching device according to this disclosure is applied. The workpiece transport system A1 of this embodiment comprises a transport chamber 91, two spare chambers 92 and 93, two processing chambers 94, and a transport robot B1, and is configured to transport, for example, a circular silicon wafer for semiconductor manufacturing as a thin plate-shaped workpiece W.

[0020] The transfer chamber 91 is a transfer chamber in which the transfer robot B1 is located. The spare chamber 92 is a load lock chamber through which the workpiece W before processing is brought in from the outside. The spare chamber 93 is an unload lock chamber through which the processed workpiece W is transported to the outside. The processing chamber 94 is for performing predetermined processing on the workpiece W and consists of a vacuum chamber in which processing is performed on the workpiece W under a vacuum environment. Opening and closing doors 99 are provided between the transfer chamber 91 and each of the two spare chambers 92, 93 and the two processing chambers 94. In addition, each of the spare chambers 92 and 93 has an opening and closing door 99 on the side opposite to the transfer chamber 91. The spare chambers 92 and 93 are switched between atmospheric pressure and vacuum each time the workpiece W is processed. The transfer chamber 91 maintains a vacuum state when the workpiece W is being transported. Furthermore, the arrangement of the transport room 91, the spare rooms 92 and 93, and the processing room 94 is not limited to the illustrated example, nor is the specific configuration of each of these elements limited in any way.

[0021] In the example illustrated in this embodiment, the z-direction corresponds to the vertical direction when the transport robot B1 is placed in the transport chamber 91.

[0022] In this embodiment, the workpiece transport system A1 includes a camera 5, a control device 6, an input unit 71, and a display unit 72 (see Figure 7). The transport robot B1 includes a fixed base 1, a lifting base 2, a horizontal arm mechanism 3, a hand unit 4, and a drive mechanism 73 (see Figures 2 and 7).

[0023] Figure 2 is a side view showing the schematic configuration of the transport robot B1. The lifting base 2 is supported by the fixed base 1 and is capable of moving up and down by a lifting mechanism (drive mechanism) not shown. The horizontal arm mechanism 3 is supported by the lifting base 2 and is a horizontal articulated arm mechanism that moves along a horizontal plane perpendicular to the z direction (vertical direction). The horizontal arm mechanism 3 is composed of, for example, a plurality of arms that are rotatably connected. In the illustrated example, the horizontal arm mechanism 3 includes a first arm 31 and a second arm 32. The base end 31a of the first arm 31 is rotatably supported around a first vertical axis O1 extending in the z direction relative to the lifting base 2. The base end 32a of the second arm 32 is rotatably supported around a second vertical axis O2 extending in the z direction at the tip of the first arm 31. Note that the configuration of the horizontal arm mechanism 3 is not limited to the illustrated example.

[0024] As shown in Figures 2 and 5, the hand portion 4 is made of a plate-like member and is supported by the second arm 32 (horizontal arm mechanism 3) in a horizontal position. The hand portion 4 is for placing and holding the workpiece W. In this embodiment, the base end of the hand portion 4 is supported so as to be rotatable around a third vertical axis O3 extending in the z direction at the tip of the second arm 32. The hand portion 4 has a base portion 41 and two holding pieces 42 extending from the base portion 41. Note that the configuration of the hand portion 4 is not limited to the illustrated example.

[0025] Multiple second markers 43 are provided on the base 41 of the hand portion 4. Details of the multiple second markers 43 will be described later.

[0026] Although a detailed illustration is omitted, the first arm 31 and the second arm 32 are rotated around the first vertical axis O1 and the second vertical axis O2 by using a motor as the drive source and a power transmission means (drive mechanism) such as a belt mechanism or a reduction gear. The hand unit 4 is also rotated around the third vertical axis O3 by using a motor as the drive source and a power transmission means (drive mechanism) such as a belt mechanism or a reduction gear. In the transport robot B1, by controlling the drive of the above-mentioned drive mechanisms, it is possible to load and unload workpieces W into and out of each of the two spare chambers 92, 93 and the two processing chambers 94.

[0027] As shown in Figures 3 and 4, the processing chamber 94, which is the destination for transport, is equipped with a stage 81, a plurality of support pins 82, and a plurality of first markers 83. The stage 81 is circular in plan view and is sized to correspond to the workpiece W in plan view. The plurality of support pins 82 support the workpiece W when the transport robot B1 loads and unloads the workpiece W into and out of the processing chamber 94. The support pins 82 are movable up and down between a raised position, where they protrude upward from the upper surface of the stage 81, and a lowered position, where they are retracted below the upper surface of the stage 81. When the workpiece W is transferred between the hand unit 4 and the workpiece W during loading or unloading, the plurality of support pins 82 are in the raised position. On the other hand, when a predetermined process is performed on the workpiece W, the plurality of support pins 82 are in the lowered position, and the workpiece W is supported on the upper surface of the stage 81 while the predetermined process is performed. In the processing chamber 94, a thin film is formed on the workpiece W by, for example, plasma CVD (Chemical Vapor Deposition) processing. The processing performed on the workpiece W in the processing chamber 94 is not particularly limited, and various processing such as etching and cleaning can be performed. Details of the multiple first markers 83 will be described later. In Figures 3 and 4, the x-direction is along the horizontal plane and is the direction of movement of the workpiece W when loading or unloading it from the processing chamber 94. The y-direction is along the horizontal plane and is perpendicular to the z-direction (vertical direction) and the x-direction. The top surface of the stage 81 is a horizontal plane (the xy-plane including the x-direction and y-direction).

[0028] As shown in Figure 4, the camera 5 is positioned above the processing chamber 94. In this embodiment, the camera 5 is positioned outside the processing chamber 94 and can capture images of the inside of the processing chamber 94, for example, through a viewport (not shown) provided on the upper wall of the processing chamber 94. The camera 5 can capture images of multiple first markers 83.

[0029] As shown in Figures 3 and 4, in this embodiment, the multiple first markers 83 are provided near the outer edge of the stage 81. The multiple first markers 83 are positioned offset to one side in the x-direction (the loading entrance side on the left in the figures).

[0030] The stage 81 is preferably provided with three or more first markers 83 that are spaced apart from each other in a plan view. In the illustrated example, the stage 81 is provided with six first markers 83. In this embodiment, each of the multiple first markers 83 is formed by a recess that is recessed from the upper surface of the stage 81. Each first marker 83 is circular in a plan view, and the coordinates of its center in a plan view are easily determined.

[0031] In the illustrated example, six first markers 83 are arranged at equal intervals in two rows in the x-direction and three rows in the y-direction. The distance d1 between the center points of adjacent first markers 83 in the x-direction and y-direction is, for example, 15 mm. The diameter of each first marker 83 is, for example, 3 mm. Furthermore, the center point P1 on the upper surface of the stage 81 and the first marker 83 at the center in the y-direction coincide in the y-direction and are separated by a predetermined distance in the x-direction. The distance d2 between the center point of the first marker 83 at the center in the y-direction and the center point P1 of the stage 81 is, for example, 120 mm. As can be understood from this, the multiple first markers 83 are at predetermined positions (first predetermined positions) with respect to the center point P1 of the stage 81. The center point P1 of the stage 81 corresponds to the "first reference position" in this disclosure. The positions of the first markers 83 and the center point P1 of the stage 81 are in a three-dimensional spatial coordinate system with respect to the processing chamber 94 (transport destination). The specific configuration of the first marker 83 is not limited to the configuration described above. Furthermore, the size of the first marker 83, the distance d1 between the center points of adjacent first markers 83, and the distance d2 between the center point of the first marker 83 at the center in the y-direction and the center point P1 of the stage 81 are not limited to the values ​​exemplified above.

[0032] As shown in Figure 5, the multiple second markers 43 provided on the base 41 of the hand portion 4 are located near the outer edge of the workpiece W when the workpiece W is placed on the hand portion 4.

[0033] Preferably, the hand portion 4 is provided with three or more second markers 43 that are spaced apart from each other in a plan view. In the illustrated example, the hand portion 4 is provided with six second markers 43. In this embodiment, each of the multiple second markers 43 is formed by a through hole that penetrates the hand portion 4 (base portion 41) in the z direction. Alternatively, each second marker 43 may be formed by a recess that is recessed from the upper surface of the hand portion 4 (base portion 41). In the illustrated example, each second marker 43 is circular in a plan view. This makes it easy to determine the coordinates of the center of the second marker 43 in a plan view.

[0034] In the hand unit 4 shown in Figure 5, if the loading and unloading direction (x direction) of the workpiece W in the processing chamber 94 is considered to be the left-right direction in the figure, then in the illustrated example, the six second markers 43 are arranged at equal intervals in two rows in the x direction and three rows in the y direction. The distance d3 between the center points of adjacent second markers 43 in the x and y directions is, for example, 15 mm. The diameter of each second marker 43 is, for example, 3 mm. Furthermore, the center point P2 set on the hand unit 4 and the second marker 43 at the center in the y direction coincide in the y direction and are separated by a predetermined distance in the x direction. Here, the center point P2 of the hand unit 4 is the so-called TCP (Tool Center Point), and in this embodiment, for example, it is the intersection point of the central axis Ow and the lower surface of the workpiece W when the workpiece W is placed on the hand unit 4. The distance d4 between the center point of the second marker 43 at the center in the y direction and the center point P2 of the hand unit 4 is, for example, 120 mm. As can be understood from the above, the multiple second markers 43 are located at predetermined positions (second predetermined positions) with respect to the center point P2 of the hand portion 4. The center point P2 of the hand portion 4 corresponds to the "second reference position" in this disclosure. Note that the specific configuration of the second markers 43 is not limited to the above configuration. Furthermore, the size of the second markers 43, the distance d3 between the center points of adjacent second markers 43, and the distance d4 between the center point of the second marker 43 at the center in the y direction and the center point P2 of the hand portion 4 are not limited to the values ​​exemplified above.

[0035] The control device 6 controls the operation of the transport robot B1 (lifting base 2, horizontal arm mechanism 3, and hand unit 4) and teaches the position of the hand unit 4. As shown in Figure 7, the control device 6 comprises a control unit 61, a storage unit 62, and a teaching unit 63. The control unit 61 controls the drive of the drive mechanism 73 based on the transport information stored in the storage unit 62. The drive mechanism 73 provides predetermined movements to the lifting base 2, the horizontal arm mechanism 3, and the hand unit 4. The control unit 61 also controls the drive of the drive mechanism 73 based on information input from the input unit 71. The input unit 71 is used by the operator to perform teaching tasks and manual operations (for example, a teach pendant). The display unit 72 displays images captured by the camera 5 and menu screens for input from the input unit 71. The teaching unit 63 calculates the teaching position of the hand unit 4 from the images captured by the camera 5. The teaching unit 63 has an image acquisition unit 631 and a position calculation unit 632. The image acquisition unit 631 acquires position data of subjects included in the image captured by the camera 5. The acquired position data is camera coordinate system data based on the camera 5. The position calculation unit 632 detects the first marker 83 and the second marker 43 from the image captured by the camera 5 and calculates the teaching position of the hand unit 4 based on the camera coordinate system position information of the first marker 83 and the second marker 43. Furthermore, the control unit 61 assists in the teaching process, which will be described later, and performs the teaching process automatically. The teaching process will be described later. The storage unit 62 stores teaching information to show the trajectory of the hand unit 4's movement. Information acquired in advance by the teaching process is recorded in the storage unit 62 and used as teaching information. Note that the configuration of the control device 6 is not limited to the example shown in Figure 7, and for example, the control device 6 may have a configuration that includes an input unit 71 and a display unit 72.

[0036] Figure 8 shows the first image (image 1) taken by camera 5 when capturing multiple first markers 83. For the images captured by camera 5, the left-right direction in the figure is defined as the x-coordinate, and the up-down direction is defined as the y-coordinate. This also applies to the images shown in Figure 9 and subsequent figures.

[0037] In this embodiment, the optical axis of the camera 5 passes through the central position of the six first markers 83. In Figure 4, the optical axis L1 of the camera 5 is represented by a dashed line, and the field of view that can be captured by the camera 5 is represented by a dashed line. In the image shown in Figure 8, the central position in the y direction is represented by auxiliary line L2, and the central position in the x direction is represented by auxiliary line L3. This is also true for the images shown in Figure 9 and subsequent figures.

[0038] In the image in Figure 8, the multiple (6) first markers 83 are arranged in two columns in the x direction and three columns in the y direction. The distance d11 between the center points of adjacent first markers 83 in the x direction is the difference in the x coordinates of the center points of adjacent first markers 83 in the x direction. The distance d11 between the center points of adjacent first markers 83 in the y direction is the difference in the y coordinates of the center points x of adjacent first markers 83 in the y direction. As explained with reference to Figure 3, the relative positions of the multiple first markers 83, and the relative positions of the multiple first markers 83 and the center point P1 of the stage 81 can be expressed using distances d1 and d2 and are known. The control device 6 can calculate the three-dimensional coordinates (x coordinate, y coordinate, and z coordinate) of the center point P1 of the stage 81 by performing calculations based on the coordinates of the multiple first markers 83. Note that, as can be understood from Figures 3 and 8, the image shown in Figure 8 does not include the center point P1 of the stage 81. Here, we will explain an example of the procedure for calculating the 3D coordinates of the center point P1 of stage 81. First, the coordinates of the first marker 83 (the coordinates of the center point of each first marker 83) are detected from the image of the first marker 83. Next, the 3D coordinates of the first marker 83 as seen from camera 5 (camera coordinate system data) are calculated from the positional relationship of multiple first markers 83 (distance d11 between the center points of adjacent first markers 83) and the focal length of camera 5. Then, the 3D coordinates of the center point P1 of stage 81 are calculated using the positional relationship between the first marker 83 and the center point P1 of stage 81 (distances d1, d2 shown in Figure 3).

[0039] Figure 9 shows an image taken by the camera 5 of multiple second markers 43 when the hand unit 4 is in the target position after teaching processing. In Figure 6, the hand unit 4 in the target position after teaching processing is represented by a dashed line. The hand unit 4 in the target position is located at a predetermined distance above the top surface of the stage 81. As a result, the hand unit 4 in the target position is closer to the camera 5 than to the stage 81. Also, when the hand unit 4 is in the target position, the optical axis of the camera 5 passes through the center position of the six second markers 43 on the hand unit 4. In this embodiment, when the hand unit 4 is in the target position, in a plan view, the center point of each of the multiple second markers 43 on the hand unit 4 coincides with the center point of the corresponding first marker 83, and the center point P2 of the hand unit 4 coincides with the center point P1 of the stage 81.

[0040] In the image in Figure 9, the multiple (6) second markers 43 are arranged in two columns in the x direction and three columns in the y direction. The distance d31 between the center points of adjacent second markers 43 in the x direction is the difference in the x coordinates of the center points of adjacent second markers 43 in the x direction. The distance d31 between the center points of adjacent second markers 43 in the y direction is the difference in the y coordinates of the x coordinates of the center points of adjacent second markers 43 in the y direction. Here, the distance from the camera 5 to the subject, the hand part 4 (multiple second markers 43), is shorter than the distance from the camera 5 to the stage 81 (multiple first markers 83). If the focal length of the camera is constant, the size of the subject image in the image is inversely proportional to the distance from the camera to the subject. As a result, as the distance from the camera to the subject decreases, the subject image in the image becomes larger. In this embodiment, the distance from the camera 5 to the subject, the hand portion 4 (multiple second markers 43), is shorter than the distance from the camera 5 to the stage 81 (multiple first markers 83). Therefore, the distance d31 between the center points of adjacent second markers 43 in the image shown in Figure 9 is greater than the distance d11 between the center points of adjacent first markers 83 in the image shown in Figure 8.

[0041] As explained with reference to Figure 5, the relative positions of the multiple second markers 43, and the relative positions of the multiple second markers 43 and the center point P2 of the hand unit 4, can be expressed using distances d3 and d4 and are known. Therefore, by detecting the multiple second markers 43 (the center points of the second markers 43) and performing calculations based on the coordinates of the multiple second markers 43 in the control device 6, the three-dimensional coordinates (x, y, and z coordinates) of the center point P2 of the hand unit 4 can be calculated. Note that, as can be seen from Figures 5 and 9, the image shown in Figure 9 does not include the center point P2 of the hand unit 4. Here, an example of the procedure for calculating the three-dimensional coordinates of the center point P2 of the hand unit 4 will be described. First, the coordinates of the second markers 43 (the coordinates of the center points of each second marker 43) are detected from the image of the second markers 43. Next, the 3D coordinates of the second markers 43 as seen from camera 5 (camera coordinate system data) are calculated from the positional relationship of the multiple second markers 43 (d31, the distance between the center points of adjacent second markers 43) and the focal length of camera 5. Then, the 3D coordinates of the center point P2 of hand unit 4 are calculated using the positional relationship between the second markers 43 and the center point P2 of hand unit 4 (distances d3, d4 shown in Figure 5).

[0042] Next, the teaching process for automatically performing the teaching task in this embodiment will be described with reference to Figure 10.

[0043] Figure 10 is a flowchart illustrating the teaching process in this embodiment. The control device 6 (control unit 61) starts the teaching process when, for example, the operator instructs it to perform the teaching process from the input unit 71. During the teaching process, the position of the hand unit 4 in the x, y, and z directions, as well as the z-axis rotation direction, are adjusted.

[0044] First, the camera 5 captures multiple first markers 83, and an image (first image) of the multiple first markers 83 is obtained (step S1 in Figure 10). As described above, Figure 8 shows the image (first image) when multiple first markers 83 are captured. Next, the center point of each first marker 83 is detected from the image (first image) of the multiple first markers 83, and the coordinates (x coordinate, y coordinate, and z coordinate) of the center point P1 (first reference position) of the stage 81 are calculated based on the coordinates of the center points of each of the multiple first markers 83 (step S2 in Figure 10).

[0045] Next, the transport robot B1 is operated to move the hand unit 4 to its initial position in the processing chamber 94 at the transport destination (step S3 in Figure 10). Then, the camera 5 captures images of the multiple second markers 43 on the hand unit 4, and an image of the multiple second markers 43 (second image) is obtained (step S4 in Figure 10). Figure 11 shows the image (second image) when the multiple second markers 43 are captured by the camera 5. Next, the center point of each second marker 43 is detected from the image of the multiple second markers 43 (second image), and the coordinates (x, y, and z coordinates) of the center point P2 (second reference position) of the hand unit 4 are calculated based on the coordinates (x, y, and z coordinates) of each of the center points of the multiple second markers 43 (step S5 in Figure 10). Then, based on the coordinates of the center point P1 (first reference position) of the stage 81 obtained in step S2 and the coordinates of the center point P2 (second reference position) of the hand unit 4, the teaching position of the hand unit 4 is calculated (step S6 in Figure 10).

[0046] Here, as can be seen by comparing Figure 11 and Figure 9, in the image shown in Figure 11, the hand unit 4 is displaced in the x, y, and z-axis rotation directions compared to when it is at the target position (image in Figure 9). In calculating the teaching position of the hand unit 4, the amount of movement of the hand unit 4 to the teaching position in the x and y directions is calculated by correcting the coordinates of the center point P2 (second reference position) of the hand unit 4 to coincide with the coordinates of the center point P1 (first reference position) of the stage 81. The amount of movement of the hand unit 4 to the teaching position in the z-axis rotation direction is calculated by correcting the coordinates (x and y coordinates) of the center points of each of the multiple second markers 43 to coincide with the coordinates (x and y coordinates) of the center points of the corresponding first markers 83.

[0047] Furthermore, the position of the center point P2 (second reference position) of the hand unit 4 in the z direction is calculated based on the distance d32 between the center points of adjacent second markers 43 in the x direction and the distance d33 between the center points of adjacent second markers 43 in the y direction. The z-direction position of the center point P2 can be calculated by performing a predetermined calculation process based on the fact that the size of the subject image in the image is inversely proportional to the distance from the camera to the subject, as explained with reference to Figure 9. This makes it possible to calculate the amount of movement of the hand unit 4 to the teaching position in the z direction, and teaching data is obtained to move the hand unit 4 to the teaching position.

[0048] Next, based on the above teaching data, the hand unit 4 is moved to the teaching position (step S7 in Figure 10). Then, the above teaching data is evaluated (step S8 in Figure 10). The evaluation of the teaching data is performed by moving the hand unit 4 to the teaching position, then photographing a plurality of second markers 43 with the camera 5, and determining whether the hand unit 4 is within a predetermined error range relative to the target position based on the images of the plurality of second markers 43. If the hand unit 4 is not within the predetermined error range relative to the target position, steps S4 to S7 are repeated.

[0049] Once the position teaching operation of the hand unit 4 is complete, the image data captured by the camera 5, the position data of the appropriate teaching position, etc., are recorded in the storage unit 62. This completes the teaching process shown in Figure 10.

[0050] Next, the operation of this embodiment will be described.

[0051] According to this embodiment, the teaching process is performed automatically by the teaching unit 63 in the control device 6. In this teaching process, the amount of manual work performed by the operator is very small and only those that can be easily performed. Therefore, the time required for the teaching process can be significantly reduced. In addition, in this embodiment, the camera 5 is positioned above the processing chamber 94 (transport destination). Therefore, the camera 5 can be installed more easily compared to, for example, mounting the camera on the hand unit 4.

[0052] In the processing chamber 94 (transport destination), a first marker 83 is provided at a predetermined position relative to the center point P1 (first reference position) of the stage 81. In the hand unit 4 of the transport robot B1, a second marker 43 is provided at a predetermined position relative to the center point P2 (second reference position) of the hand unit 4. From the image captured in a plan view by the camera 5, the coordinates of the center point P1 (first reference position) of the stage 81 are calculated based on the coordinates of the first marker 83, and the coordinates of the center point P2 (second reference position) of the hand unit 4 are calculated based on the coordinates of the second marker 43. Then, the teaching position of the hand unit 4 is calculated based on the coordinates of the center point P1 (first reference position) of the stage 81 and the coordinates of the center point P2 (second reference position) of the hand unit 4. With this configuration, it is possible to efficiently teach the position of the hand unit 4 by simple means such as providing a first marker 83 on the stage 81 (transport destination) and a second marker 43 on the hand unit 4.

[0053] Furthermore, camera 5 is positioned outside the processing chamber 94 and can photograph the inside of the processing chamber 94 through a viewport. This allows camera 5 to photograph the first marker 83 on the stage 81 and the second marker 43 on the hand unit 4 without any problems, even when the inside of the processing chamber 94, the destination of the transported material, is in a vacuum or high temperature state.

[0054] The images captured by camera 5 include a first image in which the first marker 83 is captured, and a second image in which the second marker 434 is captured. The teaching unit 63 calculates the coordinates of the center point P1 (first reference position) of the stage 81 based on the coordinates of the first marker 83 in the first image. The teaching unit 63 also calculates the coordinates of the center point P2 (second reference position) of the hand unit 4 based on the coordinates of the second marker 43 in the second image. With this configuration, when teaching the hand unit 4, even if the hand unit 4 is positioned to overlap with the first marker 83 in a plan view, the first image in which the first marker 83 is captured can be obtained in advance. Therefore, the teaching process for the hand unit 4 can be performed appropriately.

[0055] In this embodiment, the stage 81 of the processing chamber 94 (transport destination) is provided with three or more first markers 83 that are spaced apart from each other in a plan view. The hand unit 4 is provided with three or more second markers 43 that are spaced apart from each other in a plan view. With this configuration, the teaching positions of the hand unit 4 in the x, y, z, and z-axis rotation directions can be appropriately calculated. Furthermore, by increasing the number of first markers 83 and second markers 43 (six each in this embodiment), an improvement in the accuracy of the teaching positions calculated based on the coordinates of the first markers 83 and second markers 43 in the image can be expected.

[0056] Figure 12 shows another configuration example of the second marker 43 provided on the hand portion 4, and is a plan view similar to Figure 5. In the embodiment shown in Figure 5, the multiple second markers 43 provided on the hand portion 4 were positioned to overlap with the workpiece W supported by the hand portion 4 in a plan view. In contrast, in the example shown in Figure 12, the multiple second markers 43 are positioned to not overlap with the workpiece W supported by the hand portion 4 in a plan view. Also, in the example shown in Figure 12, three second markers 43 are provided. These three second markers 43 include a pair of second markers 43 adjacent to each other in the x direction and a pair of second markers 43 adjacent to each other in the y direction. With this configuration, the camera 5 can photograph the multiple second markers 43 while the workpiece W is supported by the hand portion 4. This makes it possible to photograph the second markers 43 with the camera 5 while the workpiece W is supported by the hand portion 4. Therefore, it is possible to teach the position of the hand portion 4 while the workpiece W is supported by the hand portion 4.

[0057] Figure 13 shows another example of an image (first image) when the camera 5 captures multiple first markers 83. In the embodiments shown in Figures 5 and 8, the optical axis of the camera 5 passes through the central position of the six first markers 83, which is the state when the camera 5 is precisely mounted in the designed mounting position. In contrast, in the example shown in Figure 13, the camera 5 is installed in a position offset from the designed mounting position. Even in such a case, the three-dimensional coordinates (x, y, and z coordinates) of the center point P1 of the stage 81 can be calculated by detecting multiple first markers 83 and performing calculations based on the coordinates of the center points of the multiple first markers 83. Furthermore, if the optical axis of the camera 5 is tilted with respect to the vertical, the distance d12 between the center points of adjacent first markers 83 in the x direction and the distance d13 between the center points of adjacent first markers 83 in the y direction will be different values. In this case, the tilt of the optical axis of the camera 5 can be calculated by performing predetermined calculations from the distances d12 and d13. This allows data to be acquired regarding the positional displacement of camera 5 (the amount of displacement in the x, y, and z axis rotation directions, as well as the tilt of the optical axis of camera 5). In the teaching process of the hand unit 4, this data regarding the positional displacement of camera 5 can be used for correction. This makes it possible to properly teach the position of the hand unit 4 even if the mounting position of camera 5 is misaligned.

[0058] The position teaching device and position teaching method according to this disclosure are not limited to the embodiments described above. The specific configuration of the position teaching device and position teaching method according to this disclosure can be modified in various ways. In the above embodiments, the case in which the transport destination targeted for position teaching of the hand unit 4 is the processing chamber 94 was described as an example, but this disclosure is not limited thereto. The transport destination targeted for position teaching of the hand unit 4 may be the spare chamber 92 (load lock chamber), etc. Also, in the above embodiments, the case in which the transport robot B1 is placed in the transport chamber 91 which is a transfer chamber was described, but the transport robot of this disclosure may be incorporated into, for example, an automated substrate transport system (EFEM: Equipment Front End Module). When the transport robot constitutes an EFEM, the transport destination targeted for position teaching of the hand unit may be a load port.

[0059] In the above embodiment, the first marker 83 and the second marker 43 are composed of circular recesses or through holes in a plan view, but the specific configuration of the first and second markers is not limited thereto. The first and second markers can be detected from an image captured by a camera, and positional data of a predetermined position (e.g., the center point) of the first and second markers can be obtained. The first and second markers may also be protruding pins provided on the transport destination or hand part, or laser-engraved markings, and their plan view shape is not limited to a circle. [Explanation of symbols]

[0060] B1: Transport robot, 3: Horizontal arm mechanism, 4: Hand unit, 43: Second marker, 5: Camera, 63: Teaching unit, 83: First marker, 94: Processing chamber (transport destination), P1: Center point (first reference position), P2: Center point (second reference position)

Claims

1. A position teaching device for a transport robot that transports a workpiece to a transport destination, comprising a horizontal articulated horizontal arm mechanism and a hand portion supported by the horizontal arm mechanism for supporting a workpiece, wherein the device teaches the position of the hand portion relative to the transport destination, A first marker is provided at the destination of the transport and is located at a first predetermined position relative to the first reference position, A second marker is provided on the hand portion and is located at a second predetermined position relative to the second reference position, A camera positioned above the destination of transport and capable of photographing the first marker and the second marker, The system includes a teaching unit that calculates the teaching position of the hand part from an image captured by the camera, The teaching unit calculates the coordinates of the first reference position based on the coordinates of the first marker in the image, calculates the coordinates of the second reference position based on the coordinates of the second marker in the image, and calculates the teaching position of the hand unit based on the coordinates of the first reference position and the coordinates of the second reference position, in a position teaching device.

2. The aforementioned image includes a first image in which the first marker is captured and a second image in which the second marker is captured. The position teaching device according to claim 1, wherein the teaching unit calculates the coordinates of the first reference position based on the coordinates of the first marker in the first image, and calculates the coordinates of the second reference position based on the coordinates of the second marker in the second image.

3. The position teaching device according to claim 1 or 2, comprising three or more first markers that are spaced apart from each other in a plan view, and three or more second markers that are spaced apart from each other in a plan view.

4. A position teaching method for teaching the position of the hand portion relative to a transport robot, which transports a workpiece to a transport destination, comprising a horizontal articulated horizontal arm mechanism and a hand portion supported by the horizontal arm mechanism for supporting a workpiece, wherein the transport robot transports the workpiece to a transport destination, The destination is provided with a first marker located at a first predetermined position relative to a first reference position. The hand portion is provided with a second marker located at a second predetermined position relative to the second reference position. The steps include: photographing the first marker and the second marker with a camera positioned above the destination; The step includes calculating the teaching position of the hand part from the image captured by the camera, A position teaching method comprising the step of calculating the teaching position of the hand portion, which involves calculating the coordinates of the first reference position based on the coordinates of the first marker in the image, calculating the coordinates of the second reference position based on the coordinates of the second marker in the image, and calculating the teaching position of the hand portion based on the coordinates of the first reference position and the coordinates of the second reference position.

5. The aforementioned image includes a first image in which the first marker is captured and a second image in which the second marker is captured. The position teaching method according to claim 4, wherein in the step of calculating the teaching position of the hand portion, the coordinates of the first reference position are calculated based on the coordinates of the first marker in the first image, and the coordinates of the second reference position are calculated based on the coordinates of the second marker in the second image.

6. The transport destination is provided with three or more of the first markers that are spaced apart from each other in a plan view. The position teaching method according to claim 4 or 5, wherein the hand portion is provided with three or more second markers that are spaced apart from each other in a plan view.

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