Robot control device and robot teaching method

Abstract

To provide a robot control device capable of generating teaching data which appropriately grasps a target position on the basis of image information photographed by a camera a plurality of times, and conveys an object to the target position with high accuracy.SOLUTION: A robot control device 100 includes: image information acquisition means 110 for acquiring first image information and second image information which are photographed at a first position and a second position; target position calculation means 120 for calculating target positions on the basis of each of the first image information and the second image information; robot position calculation means 130 for calculating a robot position on the basis of robot information; relay position setting means 140 for setting the second position based on the first image information as a relay position; robot control means 150 for operating a conveyance robot 200 for the relay position; and teaching data generation means 160 for storing the target position calculated on the basis of the second image information as teaching data.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a robot control device and a robot teaching method.

Background Art

[0002] In recent years, many robots have become widespread in industry. These robots are used, for example, in the assembly, welding, and conveyance of electronic components and mechanical components, thereby improving the efficiency and automation of factory production lines.

[0003] In a conveyance robot that conveys wafers used in semiconductor manufacturing equipment, teaching is performed to convey the wafer to an appropriate position. However, the accuracy of teaching depends on the knowledge and skill level of the operator, and there are cases where space saving is required to the extent that sufficient working space cannot be secured for the operator. Therefore, automation of teaching has been achieved.

[0004] For example, in the wafer conveyance robot described in Patent Document 1, a camera attached to a hand photographs a wafer placed at a pick-up position, three-dimensional information of the wafer is calculated based on the image acquired by the camera, and the hand is moved based on the three-dimensional information of the wafer to appropriately pick up the wafer.

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0006] However, in the wafer conveyance robot described in Patent Document 1, if the accuracy of the three-dimensional information of the wafer calculated based on the image acquired by the camera is low, there is a possibility that the position of the actually placed wafer cannot be grasped and the wafer cannot be appropriately picked up.

[0007] For example, if the camera's focus setting is not optimal, or if there are influences from the surrounding environment, including lighting conditions, the accuracy of the 3D information of the wafer calculated based on the image acquired by the camera may be reduced.

[0008] Furthermore, in automating teaching, it is necessary to accurately understand not only the 3D information of the wafer but also the target position where the wafer will be transported. When attempting to capture the target position for wafer transport using a camera attached to the wafer transport robot, the accuracy of the 3D information of the target position calculated based on the image acquired by the camera may be even lower because the target position is far from the camera. As a result, it becomes impossible to generate teaching data that accurately transports the wafer to the target position, leading to the problem of not being able to transport the wafer to the target position properly.

[0009] Therefore, the present invention aims to provide a robot control device and a robot teaching method that can appropriately grasp the target position based on image information captured multiple times by a camera and generate teaching data for transporting an object to the target position with high precision. [Means for solving the problem]

[0010] A robot control device according to one aspect of the present invention is a robot control device for controlling a transport robot that transports a flat object, comprising: an image information acquisition means that acquires first image information captured at a first position and second image information captured at a second position closer to the target position than the first position, using a camera attached to the transport robot, so as to include the target position to which the transport robot is moving; a target position calculation means that calculates the target position based on the first image information and the second image information, respectively; a robot position calculation means that calculates the robot position of the transport robot based on robot information including the state of each axis of the transport robot; a relay position setting means that sets the second position corresponding to the target position calculated based on the first image information as a relay position; a robot control means that operates the transport robot so that the robot position coincides with the relay position; and a teaching data generation means that stores the target position calculated based on the second image information as teaching data.

[0011] In this embodiment, the image information acquisition means acquires first image information captured by the camera at a first position and second image information captured by the camera at a second position, and the target position calculation means calculates the target position based on the first and second image information, respectively. The relay position setting means sets the second position corresponding to the target position calculated based on the first image information as a relay position, and the robot control means operates the transport robot to the relay position. The teaching data generation means stores the target position calculated based on the second image information as teaching data. As a result, it is possible to appropriately grasp the target position based on image information (first image information and second image information) captured multiple times by the camera and generate teaching data that transports the object to the target position with high precision, and to transport the object to the target position with high precision using said teaching data.

[0012] In the above embodiment, the second position may be set between the first position and the target position along the transport path of the object.

[0013] According to this embodiment, the second image information captured by the camera at the second position (relay position) is more accurate than the first image information, so the target position can be calculated with high accuracy based on the second image information. As a result, the target position can be grasped more appropriately and teaching data can be generated to transport the object to the target position with higher accuracy, and the object can be transported to the target position with higher accuracy using this teaching data. The second position is set between the first position and the target position, that is, set in front of the target position, so the second image information can be captured by the camera while avoiding collisions with equipment and obstacles located around (behind) the target position.

[0014] In the above embodiment, the second position may be set to the position before the end effector is operated in the transport robot.

[0015] According to this embodiment, although the second position is closer to the target position than the first position, for example, if the end effector is a hand, it is the position before the hand is extended, so that the hand or the object held by the hand does not collide with semiconductor manufacturing equipment or facilities.

[0016] In the above embodiment, the relay position setting means may reset the second position corresponding to the target position calculated based on the second image information as the relay position, the image information acquisition means may acquire the second image information captured by the camera at the reset relay position, the robot control means may operate the transport robot so that the robot position coincides with the relay position, and the teaching data generation means may store the target position calculated based on the second image information as teaching data.

[0017] According to this embodiment, the target position calculated based on the second image information captured by the camera at the reset second position (relay position) is of higher accuracy, so it is possible to generate teaching data that transports the object to the target position with higher accuracy, and using this teaching data, the object can be transported to the target position with even higher accuracy.

[0018] A robot teaching method according to one aspect of the present invention is a robot teaching method performed by a robot control device that controls a transport robot that transports a flat object, and includes: a first step of moving the transport robot so that the robot position of the transport robot coincides with a second position corresponding to a target position calculated based on first image information taken at a first position, including the target position to which the transport robot will move, using a camera attached to the transport robot; and a second step of storing the target position calculated based on second image information taken at the second position, including the target position to which the transport robot will move, using a camera attached to the transport robot, as teaching data.

[0019] In this embodiment, in the first step, the transport robot is moved to a second position corresponding to the target position calculated based on first image information captured by the camera at the first position, and in the second step, the target position calculated based on second image information captured by the camera at the second position is stored as teaching data. As a result, it is possible to appropriately grasp the target position based on image information (first image information and second image information) captured multiple times by the camera and generate teaching data that transports the object to the target position with high accuracy, and to transport the object to the target position with high accuracy using said teaching data. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a robot control device and a robot teaching method that can appropriately grasp the target position based on image information captured multiple times by a camera and generate teaching data for transporting an object to the target position with high precision. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic diagram showing the system configuration of a transport robot system 10 according to the first embodiment of the present invention. [Figure 2]It is a diagram illustrating a transfer robot 200 according to a first embodiment of the present invention transferring a wafer W. [Figure 3] It is a functional block diagram illustrating respective functions of a robot control device 100 according to the first embodiment of the present invention. [Figure 4] It is a diagram illustrating an installation position 15 of a semiconductor manufacturing apparatus that serves as a target position for transferring a wafer W. [Figure 5A] It is a diagram illustrating a positional relationship among the target position G, a second position (relay position P) corresponding to the target position G, and the TCP (T) of a hand 220 of the transfer robot 200, when the target position G is captured by a camera 240 at a first position so as to be included in an imaging range. [Figure 5B] It is a diagram illustrating the transfer robot 200 moved such that the TCP (T) of the hand 220 of the transfer robot 200 coincides with the second position (relay position P). [Figure 5C] It is a diagram illustrating the transfer robot 200 moved such that the TCP (T) of the hand 220 of the transfer robot 200 coincides with a target position G'. [Figure 6] It is a flowchart illustrating a processing flow of a robot teaching method M100 executed by a transfer robot system 10 according to the first embodiment of the present invention. [Figure 7A] It is a diagram illustrating a positional relationship among the target position G, a second position (relay position P) corresponding to the target position G, and the TCP of a hand 220 of the transfer robot 200, when the target position G is captured by a camera 240 at a first position so as to be included in an imaging range. [Figure 7B] It is a diagram illustrating the transfer robot 200 moved such that the TCP of the hand 220 of the transfer robot 200 coincides with the second position (relay position P). [Figure 7C] It is a diagram illustrating the transfer robot 200 moved such that the TCP (T) of the hand 220 of the transfer robot 200 coincides with a reset second position (relay position P'). [Figure 7D]This figure shows the transport robot 200 being moved so that the TCP(T) of the hand 220 on the transport robot 200 matches the target position G''. [Figure 8] This is a flowchart showing the processing flow of the robot teaching method M200 executed by the transport robot system according to the second embodiment of the present invention. [Modes for carrying out the invention]

[0022] The embodiments of the present invention will be described below in detail with reference to the drawings. The embodiments described below are merely examples of how to implement the present invention and are not intended to limit the scope of the invention. Furthermore, to facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations may be omitted.

[0023] <First Embodiment> [Configuration of the transport robot system] Figure 1 is a schematic diagram showing the system configuration of a transport robot system 10 according to the first embodiment of the present invention. As shown in Figure 1, the transport robot system 10 comprises a robot control device 100, a transport robot 200, a device control device 300, and a teach pendant 400.

[0024] The transport robot 200 is, for example, a 6-axis vertical articulated robot and has a manipulator body 210, a hand 220 as an end effector, and a hand base (base) 230 to which the hand 220 is attached. Furthermore, a camera 240 is positioned on the hand base 230. The camera 240 is, for example, composed of two cameras as a stereo camera.

[0025] The robot control device 100 is a device that controls the operation of the transport robot 200. For example, the robot control device 100 is connected to a teach pendant 400 and can acquire operation instruction information input to the teach pendant 400. Based on this operation instruction information, the robot control device 100 starts and stops the transport robot 200, and operates the arms and hands 220 by moving each axis of the manipulator body 210 to pick up an object.

[0026] Furthermore, the robot control device 100 controls the device control device 300 to, for example, use a camera 240 located on the transport robot 200 to photograph the vicinity of the transport robot 200 and acquire the captured image information.

[0027] As described above, the device control device 300 sends the acquired image information to the robot control device 100 by controlling the operation of the camera 240 based on the operation instructions from the robot control device 100.

[0028] In this example, the device control unit 300 is connected to the robot control unit 100 via a cable and is treated as a separate device from the robot control unit 100. However, the robot control unit 100 may also include its functions, in which case the robot control unit 100 and the device control unit 300, configured as a single unit, can be used as the robot control unit.

[0029] The teach pendant 400 receives input from the operator regarding operation instruction information for the transport robot 200, specifically concerning transport operations that involve transporting an object. Typically, the operator uses the teach pendant 400 to input appropriate instruction information, such as starting and stopping the transport robot 200, configuring the transport robot 200, and controlling the operation of the manipulator body 210 (arm) and hand 220, as well as registering teaching points.

[0030] Furthermore, in the embodiment of the present invention, regarding the registration of teaching points, instead of the operator sequentially registering teaching points along the operation path using the teach pendant 400 while operating the transport robot 200, the teaching points may be automatically registered during automatic teaching. Such automatic teaching is effective, for example, in environments or situations where sufficient space (workspace) for the operator to enter cannot be secured.

[0031] In Figure 1, the teach pendant 400 is connected to the robot control device 100 via a cable, but it may also be connected wirelessly. That is, the teach pendant 400 and the robot control device 100 may be equipped with a communication unit for wireless communication. By connecting the robot control device 100 and the teach pendant 400 wirelessly, the operator can input operation instruction information while moving freely without being bothered by the presence of cables or having their range of movement limited by the length of the cables.

[0032] [Wafer transport process] Figure 2 shows how a transport robot 200 according to the first embodiment of the present invention transports a wafer W. As shown in Figure 2, the transport robot 200 installed in the workspace 11 takes out the wafer W stored in the FOUPs 12 and 13 and transports the wafer W to the installation position 14 or 15 of the semiconductor manufacturing equipment while holding it in the hand 220.

[0033] Here, the transport robot 200 transports the wafer W stored in the FOUP 12 to the installation position 15. More specifically, the wafer W is placed at the target position, with the center of gravity of the three pins 15A to 15C located at the installation position 15 as the target position.

[0034] More specifically, the transport robot 200 operates the arms and hands 220 by moving each axis of the manipulator body 210 based on the operation instruction information from the robot control device 100, to hold the wafer W stored in the FOUP 12, then transports it to the installation position 15 and places it at the target position, which is the center of gravity of the three pins 15A to 15C. Here, it is preferable that the center of the wafer W is installed at the target position with high precision, and it is important for the robot control device 100 to appropriately grasp the target position. The robot control device 100 then operates the transport robot 200 so that the TCP (Tool Center Point) of the hand 220 of the transport robot 200 coincides with the target position, and it is preferable that this operation is registered as teaching data.

[0035] [Robot control system configuration] Figure 3 is a functional block diagram showing the functions of the robot control device 100 according to the first embodiment of the present invention. As shown in Figure 3, the robot control device 100 includes an image information acquisition means 110, a target position calculation means 120, a robot position calculation means 130, a relay position setting means 140, a robot control means 150, and a teaching data generation means 160.

[0036] As shown in Figure 1, the robot control device 100 is connected to the transport robot 200, the device control device 300, and the teach pendant 400, and is equipped with many functions to perform various control operations. Here, we mainly show the function of the robot control device 100 related to registering the target position for transporting the wafer W as teaching data, but it also has other configurations and functions.

[0037] The image information acquisition means 110 acquires first image information captured by the camera 240 at a first position so as to include the target position for transporting the wafer W held by the hand 220 of the transport robot 200. The image information acquisition means 110 also acquires second image information captured by the camera 240 at a second position closer to the target position than the first position so as to include the target position. For example, at both the first and second positions, the image information acquisition means 110 captures images with the camera 240 so as to include the three pins 15A to 15C located at the installation position 15 of the semiconductor manufacturing equipment.

[0038] Here, the first position is a position away from the installation position 15, and may be, for example, the position where the transport robot 200 holds the wafer W with the hand 220 and begins transporting it to the target position, or it may be a position where it has come to be approximately in front of the installation position 15 after transport has started.

[0039] Furthermore, the second position is located between the first position and the target position along the wafer W transport path, and is a position where the target position can be appropriately determined when the camera 240 takes a photograph at the second position. For example, it is desirable that the camera 240 can appropriately detect reference components, equipment, and markers that serve as the basis for calculating the target position based on the second image information captured by the camera 240 at the second position. Moreover, it is desirable that the focus set on the camera 240 is appropriate when detecting these, and that the surrounding environment, including lighting conditions, is stable.

[0040] The target position calculation means 120 calculates the target position based on the first image information acquired by the image information acquisition means 110, and calculates the target position based on the second image information acquired by the image information acquisition means 110. For example, the target position calculation means 120 detects the positions of three pins 15A to 15C from the image data using image processing for the first image information acquired by the image information acquisition means 110, and calculates the centroid position of the three pins 15A to 15C from the position information of the three pins 15A to 15C to determine the target position. Similarly, the target position calculation means 120 detects the positions of three pins 15A to 15C from the image data using image processing for the second image information acquired by the image information acquisition means 110, and calculates the centroid position of the three pins 15A to 15C from the position information of the three pins 15A to 15C to determine the target position.

[0041] Figure 4 shows the installation position 15 of the semiconductor manufacturing equipment, which is the target position for transporting the wafer W. In Figure 4, the installation position 15 of the semiconductor manufacturing equipment is shown as viewed from the opening side for transporting the wafer W to the installation position 15, and three pins 15A to 15C are arranged at the installation position 15.

[0042] First, for example, the image information acquisition means 110 acquires image data (first image information) captured by the camera 240 at a first position, including the three pins 15A to 15C located at the installation position 15. As described above, the camera 240 consists of two cameras as a stereo camera and is attached to the hand base 230 of the transport robot 200. The camera 240 captures the three pins 15A to 15C located at the installation position 15, but the first position is not constant, such as being far from the installation position 15 or being narrow due to equipment or facilities being placed in the workspace 11, and the image may not always be captured at an appropriately set focal point. In addition, the surrounding environment, including lighting conditions, is not constant, and it is possible that these factors may affect the image and prevent it from being captured properly. Therefore, the image data (first image information) captured by the camera 240 at the first position roughly determines the positions of the three pins 15A to 15C, and the target position calculation means 120 calculates the centroid position G of the three pins 15A to 15C based on the first image information and sets it as the target position G.

[0043] Next, after the transport robot 200 moves from the first position to the second position, the image information acquisition means 110 acquires image data (second image information) captured by the camera 240 at the second position so as to include the three pins 15A to 15C located at the installation position 15. Similarly, the target position calculation means 120 calculates the center of gravity G' of the three pins 15A to 15C based on the second image information and sets it as the target position G'. Since the second position is closer to the target position than the first position, the image data (second image information) captured by the camera 240 at the second position is more accurate than the first image information. Therefore, the positions of the three pins 15A to 15C can be appropriately determined, and thus the center of gravity (target position) G' of the three pins 15A to 15C calculated by the target position calculation means 120 is more accurate than that calculated based on the first image information.

[0044] In this way, the target position calculation means 120 calculates the target position G(G') based on the image data (first image information and second image information) captured by the camera 240 at the first and second positions, respectively (camera coordinate system). The target position G(G') may be recorded as XYZ coordinates in three-dimensional space, for example, as relative position coordinates from the camera 240, relative position coordinates from a predetermined position of the hand base 230, or relative position coordinates from a predetermined position of the hand 220 (for example, the tip (distal end) or the base (proximal end)).

[0045] Returning to Figure 3, the robot position calculation means 130 calculates the robot position of the transport robot 200 based on robot information including the state of each axis of the transport robot 200. For example, the robot position calculation means 130 calculates the robot position by calculating the position and orientation of the transport robot 200 based on the state of each axis of the transport robot 200 (information regarding angles, etc.). Here, the robot position calculation means 130 calculates the TCP of the hand 220 on the transport robot 200 as the robot position. That is, the transport robot 200 grasps the TCP of the hand 220 on the transport robot 200 from the state of each axis of the transport robot 200 (robot coordinate system). The TCP may be recorded as XYZ coordinates in three-dimensional space, for example, as relative position coordinates from the camera 240, relative position coordinates from a predetermined position of the hand base 230, or relative position coordinates from a predetermined position of the hand 220 (for example, the tip (distal end) or root (proximal end), etc.).

[0046] The relay position setting means 140 sets a second position as the relay position, which corresponds to the target position calculated based on the first image information. For example, the relay position setting means 140 may set a second position at a predetermined distance (e.g., 30 mm to 40 mm) away from the target position calculated based on the first image information captured by the camera 240 at the first position, towards the opening of the installation position 15, and set this second position as the relay position.

[0047] As described above, the second position is preferably located between the first position and the target position along the wafer W transport path, and is a position where the three pins 15A to 15C can be properly detected in the image data captured by the camera 240. If it is too close to the target position, the camera 240's field of view may prevent it from capturing the three pins 15A to 15C, or the positional relationship between the hand 220 and the three pins 15A to 15C may cause part of the hand 220 to obstruct the view of the pins 15A to 15C, preventing them from being captured.

[0048] Furthermore, the second position is ideally one where the focus set on the camera 240 is appropriate when detecting the three pins 15A to 15C, and where the surrounding environment, including lighting conditions, is stable.

[0049] Furthermore, the second position is preferably set to the position before the hand 220 is operated by the transport robot 200. Typically, the transport robot 200 operates its arm so that the wafer W is positioned in front of the opening side of the installation position 15 while the wafer W is held in the hand 220, and then extends the hand 220 to place the wafer W at the target position in the installation position 15 through the opening. At this time, it is preferable to capture the target position with the camera 240 so that it includes the target position before the hand 220 is extended, while the wafer W is positioned in front of the opening side of the installation position 15. In other words, if the target position is appropriately captured with the camera 240 before the hand 220 is extended, it is possible to avoid collisions between the hand 220 and the wafer W with the edge of the opening or other parts.

[0050] The robot control means 150 operates the transport robot 200 so that the robot position, which is the TCP of the hand 220 in the transport robot 200, coincides with the relay position set by the relay position setting means 140. For example, the robot control means 150 operates the arms and hands 220 by moving each axis of the manipulator body 210 in the transport robot 200 so that the TCP (robot coordinate system) of the hand 220 coincides with a second position (relay position) set a predetermined distance away from the center of gravity position G (camera coordinate system) of the three pins 15A to 15C calculated from the first image information, on the opening side of the installation position 15.

[0051] Furthermore, the robot control means 150 operates the transport robot 200 so that the robot position, which is the TCP of the hand 220 in the transport robot 200, matches the target position calculated by the target position calculation means 120 based on the second image information. For example, the robot control means 150 operates the arms and hands 220 by moving each axis of the manipulator body 210 in the transport robot 200 so that the center of gravity position G' (camera coordinate system) of the three pins 15A to 15C calculated from the second image information matches the TCP (robot coordinate system) of the hand 220.

[0052] The teaching data generation means 160 stores the point at which the transport robot 200 moves so that the TCP aligns with the center of gravity (target position) G' of the three pins 15A to 15C as teaching data in memory or the like. According to the teaching data thus stored, the transport robot 200 can take out the wafer W stored in the FOUP 12 and transport the wafer W to the installation position 15 of the semiconductor manufacturing equipment while holding it in the hand 220, with high precision so that the TCP aligns with the center of gravity (target position) of the three pins 15A to 15C located at the installation position 15.

[0053] Furthermore, the teaching data generation means 160 may store the center of gravity position (target position) G' as teaching data in memory or the like, even without actually moving the transport robot 200 by the robot control means 160, so that the TCP matches the center of gravity position (target position) G' of the three pins 15A to 15C.

[0054] [A transport robot being moved to its target location] The process of moving the TCP of the hand 220 in the transport robot 200 to the center of gravity position (target position) of the three pins 15A to 15C will be explained in detail using Figures 5A to 5C.

[0055] Figure 5A is a diagram showing the positional relationship between the target position G, the second position (relay position P) corresponding to the target position G, and the TCP(T) of the hand 220 on the transport robot 200, as captured by the camera 240 at the first position, including the target position G. As shown in Figure 5A, the robot control means 150 operates the transport robot 200 so that the TCP(T) of the hand 220 on the transport robot 200 coincides with the second position (relay position P).

[0056] Figure 5B shows the transport robot 200 moved so that the TCP(T) of the hand 220 on the transport robot 200 matches the second position (relay position P). As shown in Figure 5B, the robot control means 150 operates the transport robot 200 so that the TCP(T) of the hand 220 on the transport robot 200 matches the second position (relay position P).

[0057] In the example shown in Figure 5B, the second position (relay position P) and the TCP(T) of the hand 220 on the transport robot 200 do not perfectly coincide and are slightly misaligned. This is because, as mentioned above, the second position (relay position P) is set based on the target position G calculated from the first image information captured by the camera 240 at the first position, which roughly determines the positions of the three pins 15A to 15C. In other words, it can be said that the second position (relay position P) in the camera coordinate system and the TCP(T) in the robot coordinate system do not perfectly coincide and may be misaligned.

[0058] The image information acquisition means 110 acquires second image information captured by the camera 240 at the second position, where the TCP(T) of the hand 220 of the transport robot 200 is roughly aligned with the second position (relay position P), as shown in Figure 5B. The target position calculation means 120 then determines the positions of the three pins 15A to 15C based on the second image information and calculates the target position G' from them. In other words, since the second image information is more accurate than the first image information, the target position G calculated based on the first image information is corrected to the target position G' calculated based on the second image information.

[0059] Figure 5C shows the transport robot 200 being moved so that the TCP(T) of the hand 220 on the transport robot 200 matches the target position G'. As shown in Figure 5C, the robot control means 150 operates the transport robot 200 so that the TCP(T) of the hand 220 on the transport robot 200 matches the target position G'.

[0060] In the example shown in Figure 5C, the target position G' and the TCP(T) of the hand 220 on the transport robot 200 are close together with only a small discrepancy. This is because the discrepancy between the camera coordinate system and the robot coordinate system was reduced by correcting the target position G calculated based on the first image information to the target position G' calculated based on the second image information.

[0061] In this case, the robot control means 160 actually operated the transport robot 200 so that TCP matched the target position G', and the teaching data generation means 160 stored that point as teaching data in memory or elsewhere. However, when registering a teaching point, the target position calculation means 120 may calculate the target position G' based on the second image information and store that as teaching data in memory or elsewhere, even without actually operating the transport robot 200.

[0062] [Teaching method for generating teaching data] Next, we will explain in detail the teaching method for generating teaching data for transporting an object to a target position using the transport robot 200.

[0063] Figure 6 is a flowchart showing the processing flow of a robot teaching method M100 performed by a transport robot system 10 according to a first embodiment of the present invention. As shown in Figure 6, the robot teaching method M100 includes steps S110 to S130, each step being performed by a processor included in the robot control device 100 in the transport robot system 10.

[0064] In step S110, the transport robot 200 is moved so that its TCP matches the second position (relay position P) which corresponds to the target position G calculated based on the first image information captured by the camera 240 at the first position, including the target position for transporting the wafer W held by the transport robot 200 (first step).

[0065] As a specific example, in step S111, the image information acquisition means 110 acquires first image information captured by the camera 240 at the first position, including three pins 15A to 15C.

[0066] In step S112, the target position calculation means 120 calculates the centroid positions G of the three pins 15A to 15C based on the first image information acquired in step S111 and sets them as the target position G.

[0067] In step S113, the robot position calculation means 130 calculates the TCP of the hand 220 on the transport robot 200 as the robot position of the transport robot 200, based on robot information including the state of each axis of the transport robot 200.

[0068] In step S114, the relay position setting means 140 sets a second position (relay position P) at a predetermined distance (for example, 30 mm to 40 mm) away from the target position G calculated in step S112, towards the opening side of the installation position 15.

[0069] In step S115, the robot control means 150 operates the transport robot 200 so that the TCP of the hand 220 on the transport robot 200 matches the second position (relay position P) set in step S114.

[0070] Thus, in the first step, the transport robot 200 is moved to a second position (relay position P) based on the first image information captured at the first position.

[0071] In step S120, the transport robot 200 is moved so that its TCP matches the target position G' calculated based on the second image information captured by the camera 240 at the second position (relay position P), which includes the target position for transporting the wafer W held by the transport robot 200 (second step).

[0072] As a specific example, in step S121, the image information acquisition means 110 acquires second image information captured by the camera 240 at the second position (relay position P) so as to include the three pins 15A to 15C.

[0073] In step S122, the target position calculation means 120 calculates the centroid position G' of the three pins 15A to 15C based on the second image information acquired in step S121 and sets it as the target position G'. In other words, the target position G calculated in step S112 based on the first image information is corrected to the target position G' based on the second image information.

[0074] In step S123, the robot position calculation means 130 calculates the TCP of the hand 220 on the transport robot 200 as the robot position of the transport robot 200, based on robot information including the state of each axis of the transport robot 200.

[0075] In step S124, the robot control means 150 operates the transport robot 200 so that the TCP of the hand 220 on the transport robot 200 matches the target position G' calculated in step S122.

[0076] Thus, in the second step, the transport robot 200 is moved to the target position G' based on the second image information captured at the second position (relay position P).

[0077] In step S130, the point at which the transport robot 200 moves so that the TCP of the hand 220 on the transport robot 200 matches the target position G' calculated in step S122 is stored as teaching data in memory or elsewhere (third step).

[0078] As described above, according to the transport robot system 10, robot control device 100, and robot teaching method M100 according to the first embodiment of the present invention, the image information acquisition means 110 acquires first image information captured by the camera 240 at a first position and second image information captured by the camera 240 at a second position, and the target position calculation means 120 calculates the target position G(G'), which is the center of gravity position G(G') of the three pins 15A to 15C, based on the first image information and the second image information, respectively. The robot position calculation means 130 calculates the TCP of the hand 220 in the transport robot 200 based on robot information including the state of each axis of the transport robot 200. The relay position setting means 140 sets a second position (relay position P) corresponding to the target position G calculated based on the first image information, and the robot control means 150 operates the transport robot 200 so that the TCP of the hand 220 in the transport robot 200 matches the second position (relay position P). Furthermore, the robot control means 150 operates the transport robot 200 so that the TCP of the hand 220 on the transport robot 200 matches the target position G' calculated based on the second image information, and the teaching data generation means 160 stores the matched point as teaching data. As a result, the target position can be appropriately determined based on the image information (first image information and second image information) captured multiple times (twice in this embodiment) by the camera 240, and teaching data can be generated to transport the wafer W to the target position with high precision. Consequently, the wafer W can be transported to the target position with high precision using this teaching data.

[0079] In this embodiment, the camera 240 was configured as a stereo camera with two cameras and mounted on the hand base 230 of the transport robot 200. However, it is not limited to this configuration. It can be configured as one camera or three or more cameras, as long as it can capture images of the three pins 15A to 15C so that the three pins 15A to 15C can be clearly recognized. Furthermore, it may be mounted not on the hand base 230, but, for example, on the arm or hand 220 of the manipulator body 210.

[0080] Furthermore, although this embodiment describes the scenario in which the wafer W, which is the object, is transported from FOUPs 12 and 13 to the installation positions 14 and 15 of the semiconductor control device as an example, the present invention is not limited to this, and may also be applied to the scenario in which the wafer W, which is the object, is returned from the installation positions 14 and 15 of the semiconductor control device to FOUPs 12 and 13.

[0081] Furthermore, the present invention may also be applied, for example, to situations where an aligner is used to adjust the orientation or tilt of a wafer W. In this case, the installation position on the aligner that transports the wafer W should be used as the intermediate target position and should be appropriately calculated based on the first and second image information from the camera 240. Specifically, the installation position on the aligner may be the center position of the suction pad when the wafer is placed on a suction pad, or the center position of the holding member in the case of an edge grip type where the wafer edge is held and installed. The robot control means 150 then operates the transport robot 200 so that the TCP of the hand 220 on the transport robot 200 coincides with the intermediate target position, and the teaching data generation means 160 stores the coincided point as teaching data.

[0082] Furthermore, in this embodiment, the camera 240 captured images at two locations, the first and second positions. However, this is not limited to this. For example, multiple relay positions may be set along the transport path, and images may be captured at three or more locations. By increasing the number of relay positions and thus the number of times images are captured, the object can be transported to the target position more appropriately while appropriately avoiding collisions with semiconductor manufacturing equipment and facilities.

[0083] <Second Embodiment> Next, a transport robot system according to the second embodiment of the present invention will be described. The basic configuration of the transport robot system according to the second embodiment of the present invention is the same as that of the transport robot system 10 according to the first embodiment of the present invention, and here we will mainly describe the differences from the first embodiment of the present invention.

[0084] In this embodiment, the relay position setting means 140 differs from the first embodiment of the present invention in that it resets the relay position. When the relay position is reset by the relay position setting means 140, the process of moving the TCP of the hand 220 of the transport robot 200 to the center of gravity position (target position) of the three pins 15A to 15C will be explained in detail with reference to Figures 7A to 7D.

[0085] Figure 7A shows a view taken by camera 240 at the first position, including the target position G, the second position (relay position P) corresponding to the target position G, and the positional relationship of the TCP of the hand 220 on the transport robot 200. In Figure 7A, as explained in Figure 5A, the robot control means 150 operates the transport robot 200 so that the TCP(T) of the hand 220 on the transport robot 200 coincides with the second position (relay position P).

[0086] Figure 7B shows the transport robot 200 moved so that the TCP of the hand 220 on the transport robot 200 matches the second position (relay position P). In Figure 7A, as explained in Figure 5B, the robot control means 150 operates the transport robot 200 so that the TCP(T) of the hand 220 on the transport robot 200 matches the second position (relay position P). Here, because the camera coordinate system and the robot coordinate system do not perfectly coincide and may be misaligned, the TCP(T) of the hand 220 on the transport robot 200 and the second position (relay position P) do not perfectly coincide and are slightly misaligned.

[0087] The image information acquisition means 110 then acquires second image information captured by the camera 240 at the second position (relay position P), where the TCP(T) of the hand 220 in the transport robot 200 is roughly aligned with the second position (relay position P), as shown in Figure 7B. The target position calculation means 120 determines the positions of the three pins 15A to 15C based on the second image information and calculates the target position G' from them. The relay position setting means 140 then resets the second position (relay position P') corresponding to the target position G' calculated based on the second image information. In other words, because the second image information is more accurate than the first image information, the second position (relay position P) corresponding to the target position G calculated based on the first image information is corrected to the second position (relay position P') corresponding to the target position G' calculated based on the second image information.

[0088] Figure 7C shows the transport robot 200 being moved so that the TCP(T) of the hand 220 on the transport robot 200 matches the reset second position (relay position P'). As shown in Figure 7C, the robot control means 150 operates the transport robot 200 so that the TCP(T) of the hand 220 on the transport robot 200 matches the reset second position (relay position P').

[0089] In the example shown in Figure 7C, the reset second position (relay position P') and the TCP(T) of the hand 220 on the transport robot 200 are less than the amount of deviation shown in Figure 7B and are in close agreement. This is because the deviation between the camera coordinate system and the robot coordinate system was reduced by correcting the second position (relay position P) based on the first image information to the second position (relay position P') corresponding to the target position G calculated based on the second image information.

[0090] The image information acquisition means 110 then acquires second image information captured by the camera 240 at the second position (relay position P') where the TCP(T) of the hand 220 in the transport robot 200, as shown in Figure 7C, coincides with the reset second position (relay position P'). The target position calculation means 120 determines the positions of the three pins 15A to 15C based on the second image information and calculates the target position G'' from them. In other words, the second image information is more accurate than the first image information and is captured by the camera 240 at the reset second position (relay position P'), so the target position G'' calculated based on the second image information is even more accurate.

[0091] Figure 7D shows the transport robot 200 being moved so that the TCP(T) of the hand 220 on the transport robot 200 matches the target position G''. As shown in Figure 5C, the robot control means 150 operates the transport robot 200 so that the TCP(T) of the hand 220 on the transport robot 200 matches the target position G''.

[0092] In the example shown in Figure 7D, the target position G'' and the TCP(T) of the hand 220 on the transport robot 200 are in close agreement with less discrepancy. This is because the discrepancy between the camera coordinate system and the robot coordinate system was further reduced by calculating the target position G'' based on the second image information captured by the camera 240 at the second position (relay position P').

[0093] Figure 8 is a flowchart showing the processing flow of a robot teaching method M200 performed by a transport robot system according to a second embodiment of the present invention. As shown in Figure 8, the robot teaching method M200 includes steps S210 to S240, each step being performed by a processor included in the robot control device of the transport robot system.

[0094] In step S210, the transport robot 200 is moved so that its TCP matches the second position (relay position P) which corresponds to the target position G calculated based on the first image information captured by the camera 240 at the first position, including the target position for transporting the wafer W held by the transport robot 200 (first step). This is the same as step S110 described in Figure 6, and each step S211 to S215 is the same as each step S111 to S115.

[0095] Thus, in the first step, the transport robot 200 is moved to a second position (relay position P) based on the first image information captured at the first position.

[0096] In step S220, the transport robot 200 is moved so that its TCP matches the second position (relay position P') which corresponds to the target position G' calculated based on the second image information captured by the camera 240 at the second position (relay position P), so as to include the target position for transporting the wafer W held by the transport robot 200 (second step).

[0097] As a specific example, each step S221 to S223 is the same as each step S121 to S123 described in Figure 6, and in step S224, the relay position setting means 140 resets the second position (relay position P') to a position located a predetermined distance (for example, 30 mm to 40 mm) away from the target position G' calculated in step S222 towards the opening of the installation position 15.

[0098] In step S225, the robot control means 150 operates the transport robot 200 so that the TCP of the hand 220 on the transport robot 200 matches the second position (relay position P') set in step S224.

[0099] Thus, in the second step, the transport robot 200 is moved to a second position (relay position P') based on the second image information captured at the second position (relay position P).

[0100] In step S230, the transport robot 200 is moved so that its TCP matches the target position G'' calculated based on the second image information captured by the camera 240 at a second position (relay position P') that has been reset to include the target position for transporting the wafer W held by the transport robot 200 (third step). This corresponds to step S120 as described in Figure 6, but in step S231, unlike step S121, the image information acquisition means 110 acquires second image information captured by the camera 240 at the reset second position (relay position P') that includes the three pins 15A to 15C. Then, the transport robot 200 is operated so that the TCP of the hand 220 on the transport robot 200 (step S233) matches the target position G'' (step S232) calculated based on the second image information acquired in step S231 (step S234).

[0101] Thus, in the third step, the transport robot 200 is moved to the target position G'' based on the second image information captured at the reset second position (relay position P').

[0102] In step S240, the point at which the transport robot 200 moves so that the TCP of the hand 220 on the transport robot 200 matches the target position G'' calculated in step S232 is stored as teaching data in memory or elsewhere (fourth step).

[0103] As described above, according to the transport robot system, robot control device, and robot teaching method M200 of the second embodiment of the present invention, in addition to the effects and advantages described in the first embodiment of the present invention, the relay position setting means 140 resets the second position (relay position P') to a second position (relay position P') corresponding to the target position G' calculated based on the second image information captured by the camera 240 at the second position (relay position P), and the robot control means 150 moves the transport robot 200 so that the TCP of the hand 220 on the transport robot 200 matches the second position (relay position P'). The robot control means 150 then moves the transport robot 200 so that the TCP of the hand 220 on the transport robot 200 matches the target position G'' calculated based on the second image information captured by the camera 240 at the second position (relay position P'). The teaching data generation means 160 stores the matched point as teaching data. This allows the system to appropriately determine the target position based on image information (first image information and two second image pieces) captured multiple times (three times in this embodiment) by the camera 240, and generate teaching data for transporting the wafer W to the target position with high precision. Specifically, the target position G'' calculated based on the second image information captured by the camera 240 at the reset second position (relay position P') is even more accurate. As a result, the wafer W can be transported to the target position with even higher precision using this teaching data.

[0104] In the embodiments of the present invention, the object transported by the transport robot 200 has been described as a wafer, but the invention is not limited to this. For example, the present invention may also be applied to a transport robot that transports a flat panel, or to a transport robot that transports any other flat object.

[0105] Furthermore, the present invention is applicable not only to situations where an object is being transported, but also, for example, to situations where an object such as a wafer is being removed from a FOUP. The position of the wafer stored in the FOUP can be accurately calculated by taking multiple images using a camera and storing this target position as teaching data for the transport robot 200 to move to. This allows the transport robot 200 to appropriately remove the wafer.

[0106] Furthermore, while the present invention improves accuracy by taking multiple images of the target position using a camera and calculating the target position based on the image information from each image, at least one of the multiple images may be replaced with, for example, a sensor instead of a camera, or used in combination with a camera. It is also possible to calculate the target position with high accuracy based on the acquired image information and sensor information.

[0107] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The elements, arrangement, materials, conditions, shapes, and sizes of the embodiments are not limited to those exemplified and can be modified as appropriate. Furthermore, it is possible to partially substitute or combine the configurations shown in different embodiments. [Explanation of Symbols]

[0108] 10...Transport robot system, 11...Work space, 12,13...FOUP, 14,15...Installation position, 15A~15C...Pin, 100...Robot control device, 110...Image information acquisition means, 120...Target position calculation means, 130...Robot position calculation means, 140...Relay position setting means, 150...Robot control means, 160...Teaching data generation means, 200...Transport robot, 210...Manipulator body, 220...Hand, 230...Hand base (foundation), 240...Camera, 300...Device control device, 400...Teach pendant, G, G', G''...Center of gravity position (target position), M100, M200...Robot teaching method, P, P'...Relay position, W...Wafer, S110~S130, S111~S115, S121~S124...Each step of robot teaching method M100, S210~S240, S211~S215, S221~S225, S231~S234...Each step of robot teaching method M200

Claims

1. A robot control device for controlling a transport robot that transports flat objects, Image information acquisition means that acquires, by means of a camera attached to the transport robot, first image information captured at a first position including the target position for transporting the object held by the transport robot, and second image information captured at a second position closer to the target position than the first position, A target position calculation means that calculates the target position based on the first image information and the second image information, respectively, A robot position calculation means that calculates the robot position of the transport robot based on robot information including the state of each axis of the transport robot, A relay position setting means sets a second position as a relay position, which is set between the first position and the target position along the transport path of the object, based on the target position calculated based on the first image information, A robot control means for operating the transport robot so that the robot's position coincides with the relay position, The system includes teaching data generation means for storing the target position calculated based on the second image information as teaching data, Robot control device.

2. The second position is set to the position before the end effector is operated in the transport robot. The robot control device according to claim 1.

3. The relay position setting means resets the second position, which is set between the first position and the target position along the transport path of the object, as a relay position, based on the target position calculated based on the second image information. The image information acquisition means acquires second image information captured by the camera at the second position, which is the reset relay position. The robot control means operates the transport robot so that its position coincides with the relay position. The teaching data generation means stores the target position calculated based on the second image information as teaching data. The robot control device according to claim 1.

4. A robot teaching method performed by a robot control device that controls a transport robot that transports flat objects, A first step is to move the transport robot so that its robot position coincides with a second position set between the first position and the target position along the transport path of the object, based on a target position calculated based on first image information captured at the first position by a camera attached to the transport robot so as to include the target position for transporting the object held by the transport robot. The process includes a second step of storing as teaching data a target position calculated based on second image information captured at the second position by a camera attached to the transport robot, so as to include the target position to which the transport robot is moving. Robot teaching method.

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