Robot teaching device and target position calculation method

Abstract

This invention provides a robot teaching device and a target position calculation method that enable efficient searching of predetermined marker locations by simplifying the operation of a transport robot, and that can appropriately calculate the target position for transporting a flat object based on the location of the predetermined marker. [Solution] The robot teaching device 100 includes a first sensor 21 and a second sensor 22 positioned on the transport robot 10, a search unit 120 that searches for a light-shielding point where both the first sensor 21 and the second sensor 22 are shielded from light by repeatedly moving the transport robot 10 in a straight line towards a predetermined marker and rotating the transport robot 10 in a specific direction using a robot control unit 110, a marker position calculation unit 130 that calculates the position of a predetermined marker based on the position of the transport robot 10 at the light-shielding point, and a target position calculation unit 140 that calculates a target position for transporting a flat object based on the position of the predetermined marker.

Description

Technical Field

[0001] The present invention relates to a robot teaching device and a target position calculation method.

Background Art

[0002] In recent years, many robots have been popularized in the industrial world. Such robots are used, for example, for the assembly, welding, and conveyance of electronic components and mechanical parts, and the efficiency and automation of factory production lines are being achieved.

[0003] In a transfer robot that transfers wafers used in semiconductor manufacturing equipment, teaching for transferring the wafers to an appropriate position is performed, but the accuracy depends on the knowledge and proficiency of the operator, and there are also cases where space saving is required such that the working space of the operator cannot be sufficiently secured, so automation of teaching is being attempted.

[0004] For example, in Patent Document 1, a transmissive optical sensor including two sets of light projecting units and light receiving units is attached to a finger unit, and the finger unit is operated to a position where two optical axes simultaneously detect a target kinematic pin, thereby disclosing a technique related to a position teaching method for teaching a predetermined target position based on the detection of the kinematic pin. Note that the position where two optical axes simultaneously detect the kinematic pin is a position where both of the two optical axes are tangents to the outer peripheral circle of the kinematic pin.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the position teaching method disclosed in Patent Document 1, if the position in which the two optical axes detect the kinematic pin simultaneously is unclear, the arm is retracted, and then the swivel part is moved left and right to move the arm to an intermediate position between the positions in which each optical axis detects the kinematic pin. In other words, in the position teaching method disclosed in Patent Document 1, the position in which the two optical axes detect the kinematic pin simultaneously is searched for by retracting the arm and moving the swivel part left and right.

[0007] Therefore, the present invention aims to provide a robot teaching device and a target position calculation method that can efficiently search for the position of a predetermined marker by operating a transport robot in a simple manner, and appropriately calculate the target position for transporting a flat object based on the position of the predetermined marker. [Means for solving the problem]

[0008] A robot teaching device according to one aspect of the present invention is a robot teaching device for a transport robot that transports a flat object, comprising: a robot control unit that controls the operation of the transport robot; a first light-emitting unit arranged on the transport robot that emits first light having a first optical axis, and a second light-emitting unit that emits second light having a second optical axis intersecting the first optical axis; a first light-receiving unit capable of receiving the first light and a second light-receiving unit capable of receiving the second light; and by operating the transport robot with the robot control unit, at least a portion of the first light received by the first light-receiving unit and the light received by the second light-receiving unit are determined by a predetermined mark. The system includes a search unit that searches for a light-shielding point where at least a portion of both of the incoming second light are blocked, a marker position calculation unit that calculates the position of a predetermined marker based on the position of the transport robot at the light-shielding point searched by the search unit, and a target position calculation unit that calculates a target position for transporting a flat object based on the position of the predetermined marker calculated by the marker position calculation unit. The search unit searches for a light-shielding point by repeatedly moving the transport robot in a straight line towards the predetermined marker and rotating the transport robot in a specific direction, with the robot control unit controlling this.

[0009] In this embodiment, a transport robot is equipped with a first light-emitting unit and a first light-receiving unit, and a second light-emitting unit and a second light-receiving unit. The search unit searches for a light-shielding point by repeatedly moving the transport robot in a straight line towards a predetermined marker and rotating the transport robot in a specific direction, as controlled by the robot control unit. The marker position calculation unit calculates the position of a predetermined marker based on the position of the transport robot at the light-shielding point, and the target position calculation unit calculates the target position for transporting the flat object based on the position of the predetermined marker. As a result, the position of a predetermined marker can be efficiently searched by simply operating the transport robot, and the target position for transporting the flat object can be appropriately calculated based on the position of the predetermined marker.

[0010] In the above embodiment, if at least a portion of the first light and at least a portion of the second light are blocked by the robot control unit moving the transport robot in a straight line towards a predetermined landmark, the search unit may rotate the transport robot in a specific direction so that at least a portion of the first light or at least a portion of the second light that was blocked is received by the first light receiving unit or the second light receiving unit.

[0011] In this embodiment, the search unit causes the transport robot to move in a straight line towards a predetermined marker by the robot control unit, so that one of the first and second lights is obscured by the predetermined marker, and the robot control unit rotates the transport robot in a specific direction so that the obscured state of the first or second light is released. In other words, by having the transport robot repeatedly move forward and rotate in a specific direction, the search unit can search for the obscured point more efficiently.

[0012] In the above embodiment, the particular direction may be the direction of the position where at least a portion of the first light and at least a portion of the second light are blocked by a predetermined marker, with respect to the optical axis intersection where the first optical axis and the second optical axis intersect.

[0013] According to this embodiment, by determining the position of a predetermined marker relative to the optical axis intersection, it is possible to appropriately set a specific direction in which the transport robot rotates to release the shading state of the first or second light.

[0014] In the above embodiment, the statement that at least a portion of the first light received by the first light receiving unit is blocked by a predetermined mark, or that at least a portion of the second light received by the second light receiving unit is blocked by a predetermined mark, may include a state in which the amount of first light received by the first light receiving unit, or the amount of second light received by the second light receiving unit, is below a threshold.

[0015] According to this embodiment, even if the first and second rays are not completely blocked due to light diffraction or the like, it is possible to appropriately determine that the light is blocked.

[0016] In the above embodiment, the predetermined marker may be a pin on which a flat object is placed.

[0017] According to this embodiment, by using a pin whose relative position to the target position is known as a predetermined marker, the target position can be appropriately calculated without having to place a predetermined marker separately.

[0018] A target position calculation method according to one aspect of the present invention is a target position calculation method performed by a robot teaching device of a transport robot that transports a flat object, wherein the transport robot is equipped with a first light-emitting unit that emits first light having a first optical axis, a second light-emitting unit that emits second light having a second optical axis intersecting the first optical axis, a first light-receiving unit capable of receiving the first light, and a second light-receiving unit capable of receiving the second light, and the method comprises a robot control step that controls the operation of the transport robot, and by operating the transport robot in the robot control step, the amount of first light received by the first light-receiving unit by a predetermined marker The robot control step includes a search step for a light-shielding point in which at least a portion of the second light received by the second light-receiving unit is blocked; a marker position calculation step for calculating the position of a predetermined marker based on the position of the transport robot at the light-shielding point searched in the search step; and a target position calculation step for calculating a target position based on the position of the predetermined marker calculated in the marker position calculation step. The search step searches for a light-shielding point by repeatedly moving the transport robot in a straight line towards the predetermined marker and rotating the transport robot in a specific direction.

[0019] In this embodiment, a transport robot is equipped with a first light-emitting unit and a first light-receiving unit, and a second light-emitting unit and a second light-receiving unit. In the search step, the transport robot is repeatedly moved in a straight line towards a predetermined marker and rotated in a specific direction in the robot control step to search for a light-shielding point. In the marker position calculation step, the position of a predetermined marker is calculated based on the position of the transport robot at the light-shielding point. In the target position calculation step, the target position for transporting a flat object is calculated based on the position of the predetermined marker. As a result, the position of a predetermined marker can be efficiently searched by simply operating the transport robot, and the target position for transporting a flat object can be appropriately calculated based on the position of the predetermined marker. [Effects of the Invention]

[0020] According to the present invention, it is possible to efficiently search for the position of a predetermined mark by simply operating a transfer robot, and appropriately calculate a target position for transferring a flat object based on the position of the predetermined mark, and provide a robot teaching device and a target position calculation method.

Brief Description of Drawings

[0021] [Figure 1] It is a schematic diagram showing the system configuration of a transfer robot system 1 according to an embodiment of the present invention. [Figure 2] It is a schematic diagram showing how the transfer robot 10 operates in a clean environment. [Figure 3] It is a diagram schematically showing how two sets of optical sensors are arranged on the hand 11 of the transfer robot 10. [Figure 4] It is a functional block diagram showing each function of a robot teaching device 100 according to an embodiment of the present invention. [Figure 5] It is a diagram showing a state where the first light 21L projected from the first light projecting part 21E and the second light 22L projected from the second light projecting part 22E are blocked by the pin P1 arranged on the stage S. [Figure 6] It is a flowchart showing the flow of processing of a target position calculation method M100 for calculating a target position for transferring an object executed by a robot teaching device 100 according to an embodiment of the present invention. [Figure 7] It is a flowchart showing the flow of processing of step S106 for searching for a light blocking point where both the first sensor 21 and the second sensor 22 are in a light blocking state when it is determined that the first sensor 21 is in a light blocking state. [Figure 8] It is a transition diagram for explaining the operation of the hand 11 in the processing of step S106. [Figure 9] It is a flowchart showing the flow of processing of step S206 for searching for a light blocking point where both the second sensor 22 and the first sensor 21 are in a light blocking state when it is determined that the second sensor 22 is in a light blocking state. [Figure 10]This is a transition diagram illustrating the operation of hand 11 during the process in step S206. [Figure 11] This diagram schematically shows how two sets of optical sensors are arranged in a different manner on the hand 11 of the transport robot 10. [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] <One Embodiment> [Configuration of the transport robot system] Figure 1 is a schematic diagram showing the system configuration of a transport robot system 1 according to one embodiment of the present invention. As shown in Figure 1, the transport robot system 1 comprises a transport robot 10, a sensor monitoring device 20, a robot control device 30, and an operating device 40.

[0024] The transport robot 10 is, for example, a horizontal articulated robot intended for wafer transport, and is a clean transport robot used for transport in clean environments in the manufacturing of semiconductor devices and flat panel displays, and in the medical and food industries. In this embodiment, the transport robot 10 is, for example, a two-axis or three-axis cylindrical coordinate type, and has a hand 11 as an end effector, and is described as a robot that holds and transports wafers (objects) with the hand 11.

[0025] The hand 11 is equipped with two sets of optical sensors. These two sets of optical sensors may be, for example, fiber optic sensors having a light-emitting unit that emits light and a light-receiving unit that can receive the light emitted from the light-emitting unit. Details regarding the arrangement of the two sets of optical sensors will be described later.

[0026] The sensor monitoring device 20 controls and monitors the two sets of optical sensors located on the hand 11. For example, the sensor monitoring device 20 may control the light emitted from each light-emitting part of the two sets of optical sensors, or it may monitor each light-receiving part of the two sets of optical sensors and detect the light (amount of light received) received by each light-receiving part.

[0027] The robot control device 30 is a device that controls the operation of the transport robot 10. For example, the robot control device 30 is connected to the operating device 40 and can acquire operation instruction information input to the operating device 40. Based on this operation instruction information, the robot control device 30 operates each axis of the transport robot 10, as well as the arms and hands 11, to start and stop the transport robot 10, pick up an object, transport and place it.

[0028] The operating device 40 is, for example, a teach pendant, and receives input from the operator regarding operation instruction information for the transport robot 10, specifically concerning transport operations that transport an object. Typically, the operator uses the teach pendant to input appropriate instruction information for, for example, starting and stopping the transport robot 10, as well as settings for the transport robot 10, the operation of the arm and hand 11, and the registration of teaching points.

[0029] Furthermore, regarding the registration of teaching points, the operator may sequentially register the teaching points along the movement path using a teach pendant while operating the transport robot 10, or the teaching points may be automatically registered in automatic teaching. Automatic teaching is effective, for example, in environments or situations where sufficient space (workspace) for the operator to enter cannot be secured.

[0030] In Figure 1, the operating device 40 is connected to the robot control device 30 via a cable, but it may also be connected wirelessly. That is, the operating device 40 and the robot control device 30 may be equipped with a communication unit for wireless communication. By connecting the robot control device 30 and the operating device 40 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.

[0031] [Wafer transport process] Figure 2 is a schematic diagram showing how the transport robot 10 operates in a clean environment. As shown in Figure 2, the transport robot 10, installed in the workspace WS, holds the wafer W in its hand 11 and transports it to each stage S1 to S3 (hereinafter sometimes collectively referred to as "stage S") in the process chamber under vacuum conditions.

[0032] Specifically, the transport robot 10 operates its arms and hands 11 based on motion instruction information from the robot control device 30 to pick up wafers W and transport them to the destination stage S.

[0033] Here, the target position for transporting and placing the wafer W is, for example, the center of the stage S, and it is preferable that the wafer W be placed with high precision at the center of the stage S. The robot control device 30 actually transports the wafer W and places it at the target position, the center of the stage S, based on the teaching data. At that time, the robot control device 30 can generate high-precision teaching data by detecting predetermined markers placed on the stage S and appropriately determining the center position (target position) of the stage S based on these predetermined markers. As a result, the wafer W can be placed with high precision at the center of the stage S.

[0034] In other words, it is important to accurately determine the center position (target position) of stage S by appropriately detecting the positions of predetermined markers placed on stage S. Below, we will explain a method for accurately determining the center position (target position) of stage S by appropriately detecting the positions of predetermined markers placed on stage S using two sets of optical sensors placed on hand 11.

[0035] [Configuration of two sets of optical sensors] Figure 3 is a schematic diagram showing how two sets of optical sensors are arranged on the hand 11 of the transport robot 10. As shown in Figure 3, two sets of optical sensors are arranged at the tip of the hand 11: a first light-emitting unit 21E and a first light-receiving unit 21R (hereinafter sometimes referred to as "first sensor 21") and a second light-emitting unit 22E and a second light-receiving unit 22R (hereinafter sometimes referred to as "second sensor 22").

[0036] The first light-emitting unit 21E is positioned at the tip (tip side) of the hand 11 and emits the first light 21L toward the base end of the hand 11, spanning the central spatial region at the tip of the hand 11.

[0037] The first light-receiving unit 21R is positioned to correspond to the first light-emitting unit 21E. The first light-receiving unit 21R is positioned on the base end side of the hand 11, straddling the central spatial region at the tip of the hand 11, relative to the first light-emitting unit 21E which is located at the tip of the hand 11, and is capable of receiving the first light 21L emitted by the first light-emitting unit 21E.

[0038] The second light-emitting unit 22E is positioned at the tip (tip side) of the hand 11, facing the first light-emitting unit 21E through the central spatial region at the tip of the hand 11. The second light-emitting unit 22E projects a second light 22L toward the base end of the hand 11, straddling the central spatial region at the tip of the hand 11.

[0039] The second light-receiving unit 22R is positioned to correspond to the second light-emitting unit 22E. The second light-receiving unit 22R is positioned on the base end side of the hand 11, straddling the central spatial region at the tip of the hand 11, relative to the second light-emitting unit 22E which is located at the tip of the hand 11, and is capable of receiving the second light 22L emitted by the second light-emitting unit 22E.

[0040] The first light 21L, emitted from the first light-emitting unit 21E and received by the first light-receiving unit 21R, has a first optical axis 21AX, and the second light 22L, emitted from the second light-emitting unit 22E and received by the second light-receiving unit 22R, has a second optical axis 22AX. The optical axis intersection point PX, where the first optical axis 21AX and the second optical axis 22AX intersect, is located in the central spatial region at the tip of the hand 11.

[0041] Thus, two sets of optical sensors (first sensor 21 and second sensor 22) are positioned at the tip of the hand 11, and the information detected by the first sensor 21 and second sensor 22 is monitored (acquired) by the sensor monitoring device 20.

[0042] [Configuration of the robot teaching device] Figure 4 is a functional block diagram showing the functions of a robot teaching device 100 according to one embodiment of the present invention. As shown in Figure 4, the robot teaching device 100 has a functional configuration comprising a robot control unit 110, a search unit 120, a landmark position calculation unit 130, and a target position calculation unit 140, and controls the operation of the transport robot 10 (hand 11) while monitoring information detected by the first sensor 21 and the second sensor 22.

[0043] Of these functions, the robot control unit 110 is a function of the robot control device 30. The search unit 120, the landmark position calculation unit 130, and the target position calculation unit 140 may all be provided in either the sensor monitoring device 20, which monitors information detected by the first sensor 21 and the second sensor 22, or the robot control device 30, or the functions may be distributed between the sensor monitoring device 20 and the robot control device 30. Furthermore, some or all of the functions may be provided in other information processing devices other than the sensor monitoring device 20 and the robot control device 30, in cooperation with the sensor monitoring device 20 and the robot control device 30.

[0044] The robot control unit 110 controls the operation of the transport robot 10. For example, the transport robot 10 has a first sensor 21 and a second sensor 22 positioned at the tip of the hand 11, and the robot control unit 110 controls the operation of the transport robot 10 based on the information detected by the first sensor 21 and the second sensor 22.

[0045] The search unit 120 operates the transport robot 10 via the robot control unit 110 to search for a light-shielding point where at least a portion of the first light 21L received by the first light-receiving unit 21R and at least a portion of the second light 22L received by the second light-receiving unit 22R are blocked by a predetermined marker.

[0046] The designated marker may be, for example, one of the three pins located on the stage S, and the light-shielding point refers to the position (including the orientation) of the transport robot 10 (hand 11) where the first light 21L emitted from the first light-emitting unit 21E and the second light 22L emitted from the second light-emitting unit 22E are shielded by the pin, resulting in a light-shielding state.

[0047] Here, the light-shielding state is not limited to a state in which the first light 21L emitted from the first light-emitting unit 21E and the second light 22L emitted from the second light-emitting unit 22E are completely blocked by the pin. For example, 50% of the first light 21L emitted from the first light-emitting unit 21E and the second light 22L emitted from the second light-emitting unit 22E may be used as a threshold, and the amount of light received by the first light-receiving unit 21R and the second light-receiving unit 22R may fall below this threshold. This allows for appropriate determination of a light-shielding state in which the first light 21L emitted from the first light-emitting unit 21E and the second light 22L emitted from the second light-emitting unit 22E are blocked by the pin, even if complete light shielding is not achieved due to, for example, light diffraction.

[0048] Figure 5 shows how the first light 21L emitted from the first light-emitting unit 21E and the second light 22L emitted from the second light-emitting unit 22E are blocked by pins P1 positioned on the stage S. The three pins P1 to P3 may be cylindrical, conical, or truncated cone-shaped, for example, and are arranged at equal intervals with respect to the center position P0 of the stage S, which is the target position for transporting and placing the wafer W. Their positional relationship is known in advance.

[0049] As shown in Figure 5, the search unit 120 uses pin P1 of the three pins P1 to P3 located on the stage S to search for a light-shielding point where the first light 21L emitted from the first light-emitting unit 21E and the second light 22L emitted from the second light-emitting unit 22E are blocked. In other words, the search unit 120 searches for a light-shielding point by having the robot control unit 110 operate the transport robot 10 based on the amount of light received by the first light-receiving unit 21R and the amount of light received by the second light-receiving unit 22R.

[0050] The marker position calculation unit 130 calculates the position of a predetermined marker based on the position of the transport robot 10 at the light-shielding point searched by the search unit 120. For example, the marker position calculation unit 130 determines the positions (robot coordinate system) of points P11 and P12 on the outer surface of the pin P1 based on the position of the transport robot 10 at the light-shielding point. Then, since the pin P1 has a circular shape (cross-section) and the radius of the circle is known in advance, the marker position calculation unit 130 calculates the center position P10 of the circular shape (cross-section) of the pin P1 based on the positions of points P11 and P12 on the circumference.

[0051] The target position calculation unit 140 calculates the target position for transporting a flat object based on the position of a predetermined marker calculated by the marker position calculation unit 130. For example, since the positional relationship between the center position P10 of pin P1 and the center position P0 of stage S (the target position for transporting and setting the wafer W) is known in advance, the target position calculation unit 140 calculates the target position for transporting and setting the wafer W (the center position P0 of stage S) based on the center position P10 of pin P1 calculated by the marker position calculation unit 130.

[0052] In this way, the robot teaching device 100 calculates the positions of points P11 and P12 on the outer periphery of pin P1 (robot coordinate system) based on the position of the transport robot 10 at the light-shielding point, calculates the center position P10 of the circular shape (cross-section) of pin P1, and can calculate the target position (center position P0 of the stage S) with high accuracy. As a result, it is possible to appropriately grasp the target position (center position P0 of the stage S) and generate high-precision teaching data, so that the wafer W can be placed with high precision at the center of the stage S.

[0053] [Method for calculating the target position when transporting a flat object] Next, we will explain in detail how to determine the position of pin P1 (center position P10) placed on stage S and calculate the target position (center position P0) for transporting the flat object.

[0054] Figure 6 is a flowchart showing the processing flow of a target position calculation method M100, which calculates the target position for transporting an object executed by a robot teaching device 100 according to one embodiment of the present invention. As shown in Figure 6, the target position calculation method M100 includes steps S101 to S109 and steps S205 and S206, each step being mainly performed by a processor included in the sensor monitoring device 20, robot control device 30 and / or other information processing device that constitute the robot teaching device 100.

[0055] First, as explained using Figure 3, the hand 11 of the transport robot 10 is equipped with a first sensor 21 and a second sensor 22. Specifically, the tip of the hand 11 is equipped with a first light-emitting unit 21E that emits a first light 21L having a first optical axis 21AX, a second light-emitting unit 22E that emits a second light 22L having a second optical axis 22AX that intersects with the first optical axis 21AX (referred to as the optical axis intersection point PX), a first light-receiving unit 21R capable of receiving the first light 21L, and a second light-receiving unit 22R capable of receiving the second light 22L.

[0056] In step S101, the robot control unit 110 moves the transport robot 10 (hand 11) forward (in the X-axis direction). Specifically, the robot control unit 110 moves the hand 11 in a straight line towards the pin P1 located on the stage S.

[0057] In step S102, the robot teaching device 100 determines whether the first sensor 21 or the second sensor 22 is in a light-shielding state. Specifically, the robot teaching device 100 determines whether the amount of light received by the first light receiving unit 21R and the second light receiving unit 22R is less than a threshold (for example, 50% of the first light 21L emitted from the first light emitting unit 21E), thus determining whether it is in a light-shielding state.

[0058] If it is determined that the first sensor 21 or the second sensor 22 is in a light-shielding state ("Yes" in step S102), the process proceeds to step S103, and the robot control unit 110 stops the transport robot 10 (hand 11) from moving forward (in the X-axis direction). On the other hand, if it is determined that the first sensor 21 or the second sensor 22 is not in a light-shielding state ("No" in step S102), the process returns to step S101, and the robot control unit 110 continues the transport robot 10 (hand 11) from moving forward (in the X-axis direction).

[0059] In other words, the robot control unit 110 continues to move the transport robot 10 (hand 11) forward (in the X-axis direction) until it determines that the first sensor 21 or the second sensor 22 is in a light-shielding state.

[0060] If it is determined that the first sensor 21 is in a light-shielding state ("Yes" in step S104), the process proceeds to step S105, and the robot teaching device 100 determines that pin P1 is to the left in the forward direction of the optical axis intersection point PX.

[0061] In step S106, the search unit 120 repeatedly rotates the transport robot 10 (hand 11) counterclockwise (in the θ-axis direction) and moves it forward (in the X-axis direction) as instructed by the robot control unit 110, in order to search for a light-shielding point where both the first sensor 21 and the second sensor 22 are in a light-shielding state.

[0062] Furthermore, the process in step S106 will be explained in detail. Figure 7 is a flowchart showing the processing flow of step S106, in which, when it is determined that the first sensor 21 is in a light-shielding state, a light-shielding point is searched for in which both the first sensor 21 and the second sensor 22 are in a light-shielding state. Figure 8 is a transition diagram illustrating the operation of the hand 11 in the processing of step S106.

[0063] In Figure 8(A), the first sensor 21 is shielded from light by moving the transport robot 10 (hand 11) forward (in the X-axis direction) (steps S101-S104), and pin P1 is located to the left of the optical axis intersection point PX in the forward direction (step S105).

[0064] In step S1061, the search unit 120 causes the robot control unit 110 to rotate the transport robot 10 (hand 11) counterclockwise (in the θ-axis direction). Here, the robot control unit 110 may rotate the transport robot 10 (hand 11) by a predetermined angle, or it may rotate it by a predetermined angle in small increments multiple times, or it may rotate it by a predetermined angle gradually and continuously.

[0065] Furthermore, when rotating by a predetermined angle in small increments over multiple steps, the angle of rotation may be the same, or it may be gradually reduced. Also, when rotating by a predetermined angle gradually and continuously, the rotation may be performed at a constant speed, or the speed may be gradually reduced.

[0066] In step S1062, the search unit 120 determines whether the light-shielding state of the first sensor 21, which was previously in a light-shielding state, has been released. Specifically, the search unit 120 determines whether the amount of light received by the first light-receiving unit 21R is equal to or greater than a threshold. Here, the threshold may be, for example, 50% of the first light 21L emitted from the first light-emitting unit 21E, as with the threshold described above, or it may be greater than the threshold described above (for example, 60% of the first light 21L emitted from the first light-emitting unit 21E).

[0067] Here, as shown in Figure 8(B), if it is determined that the light-shielding state of the first sensor 21 has been released by rotating the transport robot 10 (hand 11) counterclockwise (in the θ-axis direction) ("Yes" in step S1062), the process proceeds to step S1063, and the robot control unit 110 stops the counterclockwise rotation (in the θ-axis direction) of the transport robot 10 (hand 11). On the other hand, if it is not determined that the light-shielding state of the first sensor 21 has been released even when the transport robot 10 (hand 11) is rotated counterclockwise (in the θ-axis direction) ("No" in step S1062), the process returns to step S1061, and the robot control unit 110 continues the counterclockwise rotation (in the θ-axis direction) of the transport robot 10 (hand 11).

[0068] In other words, the robot control unit 110 continues to rotate the transport robot 10 (hand 11) counterclockwise (in the θ-axis direction) until it determines that the light-shielding state of the first sensor 21 has been released.

[0069] In step S1064, the search unit 120 moves the transport robot 10 (hand 11) forward (in the X-axis direction) via the robot control unit 110.

[0070] In step S1065, the search unit 120 determines, using the robot teaching device 100, whether the first sensor 21 is in a light-shielded state.

[0071] Here, as shown in Figure 8(C), if it is determined that the first sensor 21 is in a light-shielding state by moving the transport robot 10 (hand 11) forward (in the X-axis direction) ("Yes" in step S1065), the process proceeds to step S1066, where the search unit 120 determines whether the second sensor 22 is also in a light-shielding state. On the other hand, if it is determined that the first sensor 21 is not in a light-shielding state ("No" in step S1065), the process returns to step S1064, and the robot control unit 110 continues to move the transport robot 10 (hand 11) forward (in the X-axis direction).

[0072] In other words, the robot control unit 110 continues to move the transport robot 10 (hand 11) forward (in the X-axis direction) until it determines that the first sensor 21 is in a light-shielding state.

[0073] Then, as shown in Figure 8(D), if it is determined that the second sensor 22 is also in a light-shielding state ("Yes" in step S1066), in step S1067, the robot control unit 110 stops the transport robot 10 (hand 11) from moving forward (in the X-axis direction). On the other hand, if it is determined that the second sensor 22 is not in a light-shielding state ("No" in step S1066), the process returns to step S1061, and the robot control unit 110 continues the counterclockwise rotation (in the θ-axis direction) of the transport robot 10 (hand 11).

[0074] If step S1061 is repeated, the robot control unit 110 may rotate the transport robot 10 (hand 11) by the same angle as the previous rotation, or by a smaller angle than the previous rotation.

[0075] In this way, the robot control unit 110 repeatedly rotates the transport robot 10 (hand 11) counterclockwise (in the θ-axis direction) and moves it forward (in the X-axis direction) to search for a light-shielding point where both the first sensor 21 and the second sensor 22 are in a light-shielding state, as shown in Figure 8(D).

[0076] Returning to the explanation of Figure 6, in step S107, the marker position calculation unit 130 obtains the positions of two points on the outer periphery of pin P1 based on the position of the transport robot 10 at the light-shielding point explored in step S106. Specifically, the marker position calculation unit 130 calculates the positions of points P11 and P12 on the circumference, as explained using Figure 5, based on the position (including orientation) of the transport robot 10 (hand 11) at the light-shielding point where both the first sensor 21 and the second sensor 22 are in a light-shielding state, as shown in Figure 8(D).

[0077] In step S108, the marker position calculation unit 130 calculates the center position of pin P1 based on the positions of two points on the outer surface of pin P1 calculated in step S107. Specifically, as explained with reference to Figure 5, the marker position calculation unit 130 calculates the center position P10 of pin P1 based on the positions of points P11 and P12 on the circumference.

[0078] In step S109, the target position calculation unit 140 calculates the center position (target position) of the stage S based on the center position P10 of the pin P1 calculated in step S108. Specifically, as explained with reference to Figure 5, the target position calculation unit 140 has prior knowledge of the positional relationship between the position of the pin P1 and the center position P0 of the stage S (the target position where the wafer W is transported and placed), and therefore calculates the center position P0 of the stage S (the target position where the wafer W is transported and placed) based on the center position P10 of the pin P1.

[0079] As described above, first, if the light-shielding state of the first sensor 21 is determined ("Yes" in step S104), the light-shielding point is searched in step S106 to calculate the center position P10 of pin P1, thereby calculating the center position P0 of the stage S (the target position where the wafer W is transported and placed).

[0080] On the other hand, if it is not determined in step S104 that the first sensor 21 is in a light-shielding state ("No" in step S104), that is, if it is determined that the second sensor 22 is in a light-shielding state, the process proceeds to step S205, and the robot teaching device 100 determines that pin P1 is to the right in the forward direction of the optical axis intersection point PX.

[0081] In step S206, the search unit 120 repeatedly rotates the transport robot 10 (hand 11) clockwise (in the θ-axis direction) and moves it forward (in the X-axis direction) as instructed by the robot control unit 110, in order to search for a light-shielding point where both the second sensor 22 and the first sensor 21 are in a light-shielding state.

[0082] Figure 9 is a flowchart showing the processing flow of step S206, which searches for a light-shielding point where both the second sensor 22 and the first sensor 21 are in a light-shielding state when it is determined that the second sensor 22 is in a light-shielding state. Figure 10 is a transition diagram illustrating the operation of the hand 11 in the processing of step S206.

[0083] In Figure 10(A), the second sensor 22 is shielded from light by moving the transport robot 10 (hand 11) forward (in the X-axis direction) (steps S101-S104), and pin P1 is located to the right of the optical axis intersection point PX in the forward direction (step S205).

[0084] Step S2061 differs from step S1061 in that the search unit 120 rotates the transport robot 10 (hand 11) clockwise (in the θ-axis direction) by the robot control unit 110.

[0085] In step S2062, the search unit 120 determines whether the light-shielding state of the second sensor 22, which was previously in a light-shielding state, has been released. Specifically, similar to step S1062, the search unit 120 determines whether the amount of light received by the second light-receiving unit 22R has exceeded a threshold.

[0086] Here, the robot control unit 110 rotates the transport robot 10 (hand 11) clockwise (in the θ-axis direction) and continues the clockwise rotation (in the θ-axis direction) of the transport robot 10 (hand 11) until it is determined that the light-shielding state of the second sensor 22 has been released. When it is determined that the light-shielding state of the second sensor 22 has been released, the process proceeds to step S2063, and the robot control unit 110 stops the clockwise rotation (in the θ-axis direction) of the transport robot 10 (hand 11) (Figure 10(B)).

[0087] In step S2064, the search unit 120 moves the transport robot 10 (hand 11) forward (in the X-axis direction) via the robot control unit 110.

[0088] In step S2065, the search unit 120 determines, using the robot teaching device 100, whether the second sensor 22 is in a light-shielded state.

[0089] Here, the robot control unit 110 moves the transport robot 10 (hand 11) forward (in the X-axis direction) and continues moving the transport robot 10 (hand 11) forward (in the X-axis direction) until the second sensor 22 determines that it is in a light-shielding state (Figure 10(C)).

[0090] Then, as shown in Figure 10(D), if the search unit 120 determines that the first sensor 21 is also in a light-shielding state ("Yes" in step S2066), in step S2067, the robot control unit 110 stops the forward movement (X-axis direction) of the transport robot 10 (hand 11). On the other hand, if it is determined that the first sensor 21 is not in a light-shielding state ("No" in step S2066), the process returns to step S2061, and the robot control unit 110 continues the clockwise rotation (θ-axis direction) of the transport robot 10 (hand 11).

[0091] In this way, the robot control unit 110 repeatedly rotates the transport robot 10 (hand 11) clockwise (in the θ-axis direction) and moves it forward (in the X-axis direction) to search for a light-shielding point where both the second sensor 22 and the first sensor 21 are in a light-shielding state, as shown in Figure 10(D).

[0092] As described above, first, if the light-shielding state of the second sensor 22 is determined (No in step S104), the light-shielding point is searched for in step S206 and the center position P10 of pin P1 is calculated, thereby calculating the center position P0 of the stage S (the target position where the wafer W is transported and placed).

[0093] As described above, according to the robot teaching device 100 and target position calculation method M100 according to one embodiment of the present invention, a first sensor 21 (first light-emitting unit 21E and first light-receiving unit 21R) and a second sensor 22 (second light-emitting unit 22E and second light-receiving unit 22R) are arranged on the hand 11 of the transport robot 10. The search unit 120 repeatedly moves the transport robot 10 (hand 11) forward and rotates the transport robot 10 (hand 11) counterclockwise or clockwise, as controlled by the robot control unit 110, to search for a light-shielding point where both the first sensor 21 and the second sensor 22 are in a light-shielding state by pin P1. The marker position calculation unit 130 calculates the center position P10 of pin P1 based on the position (including orientation) of the transport robot 10 at the light-shielding point, and the target position calculation unit 140 calculates the target position P0 (center position of stage S) for transporting the wafer W based on the center position P10 of pin P1. As a result, by operating the transport robot 10 in a simple manner, the center position P10 of pin P1 can be efficiently searched, and the target position P0 for transporting the wafer W can be appropriately calculated based on the center position P10 of pin P1.

[0094] In this embodiment, the center position P10 of pin P1, which is located on the stage S, was calculated using pin P1 as a predetermined marker. However, the predetermined marker is not limited to pin P1, and may be other pins, such as pin P2. Furthermore, if the relative positional relationship with the target position P0 (center position of the stage S) where the wafer W is transported is known, a pin other than the one located on the stage S may be used as the predetermined marker.

[0095] Furthermore, in this embodiment, the first sensor 21 and the second sensor 22 were arranged with the first light-emitting unit 21E and the second light-emitting unit 22E on the tip side and the first light-receiving unit 21R and the second light-receiving unit 22R on the base end side of the tip of the hand 11, respectively. However, the arrangement of the light-emitting and light-receiving units is not limited to these.

[0096] Figure 11 schematically shows how two sets of optical sensors are arranged on the hand 11 of the transport robot 10 in a different manner. As shown in Figure 11, the first light receiving unit 21R and the second light receiving unit 22R are arranged at the tip end of the hand 11, and the first light emitting unit 21E and the second light emitting unit 22E are arranged at the base end.

[0097] Furthermore, while the first sensor 21 and second sensor 22 were arranged on the hand 11, consisting of a first light-emitting unit 21E and a first light-receiving unit 21R, and a second light-emitting unit 22E and a second light-receiving unit 22R, for example, the sensor set containing the first sensor 21 and the second sensor 22 may be held or attached to the hand 11.

[0098] Furthermore, although optical sensors were used as the first sensor 21 and the second sensor 22 in this embodiment, contact sensors may also be used, for example. For example, sensing units may be provided at positions corresponding to the first optical axis 21AX and the second optical axis 22AX, and the position (including orientation) of the transport robot 10 where both of these contact the pin P1 (corresponding to the light-shielding point) may be searched.

[0099] 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]

[0100] 1...Transport robot system, 10...Transport robot, 11...Hand, 20...Sensor monitoring device, 30...Robot control device, 40...Operating equipment, 100...Robot teaching device, 110...Robot control unit, 120...Search unit, 130...Marker position calculation unit, 140...Target position calculation unit, S, S1~S3...Stage, W...Wafer, WS...Workspace, 21, 22...Sensor, 21E, 22E...Light emitting unit, 21R, 22R...Light receiving unit, 21L, 22L... Light, 21AX, 22AX... Optical axis, PX... Optical axis intersection, P0... Center position of stage S, P1~P3... Pins, P10... Center position of pin P1, P11, P12... Points on the outer periphery of pin P1, M100... Target position calculation method, S101~S109, S205, S206... Each step of target position calculation method M100, Steps S1061~S1067... Details of step S106, Steps S2061~S2067... Details of step S206

Claims

1. A robot teaching device for a transport robot that transports flat objects, A robot control unit that controls the operation of the transport robot, The transport robot is equipped with a first light-emitting unit that emits a first light having a first optical axis, and a second light-emitting unit that emits a second light having a second optical axis intersecting the first optical axis, A first light-receiving unit capable of receiving the first light and a second light-receiving unit capable of receiving the second light, A search unit that operates the transport robot by the robot control unit to search for a light-shielding point in which at least a portion of the first light received by the first light receiving unit and at least a portion of the second light received by the second light receiving unit are both shielded by a predetermined marker, A marker position calculation unit calculates the position of a predetermined marker based on the position of the transport robot at the light-shielding point searched by the search unit, The system includes a target position calculation unit that calculates a target position for transporting the flat object based on the position of the predetermined marker calculated by the marker position calculation unit, The search unit searches for the light-shielding point by repeatedly moving the transport robot in a straight line towards the predetermined marker and rotating the transport robot in a specific direction, as controlled by the robot control unit. Robot teaching device.

2. If at least a portion of the first light and at least a portion of the second light are blocked by the robot control unit moving the transport robot in a straight line towards the predetermined marker, the search unit will cause the robot control unit to rotate the transport robot in the specific direction so that at least a portion of the first light or at least a portion of the second light that was blocked is received by the first light receiving unit or the second light receiving unit. The robot teaching device according to claim 1.

3. The aforementioned specific direction is the direction of the position where at least a portion of the first light and at least a portion of the second light are blocked by the predetermined marker, with respect to the optical axis intersection point where the first optical axis and the second optical axis intersect. The robot teaching device according to claim 1.

4. The statement that at least a portion of the first light received by the first light receiving unit is blocked by the predetermined mark, or that at least a portion of the second light received by the second light receiving unit is blocked by the predetermined mark, includes a state in which the amount of the first light received by the first light receiving unit, or the amount of the second light received by the second light receiving unit, is below a threshold. The robot teaching device according to claim 1.

5. The aforementioned predetermined marker is a pin on which the flat object is placed. The robot teaching device according to claim 1.

6. A target position calculation method for calculating the target position for transporting a flat object, which is performed by a robot teaching device of a transport robot that transports a flat object, The transport robot is equipped with a first light-emitting unit that emits a first light having a first optical axis, a second light-emitting unit that emits a second light having a second optical axis intersecting the first optical axis, a first light-receiving unit capable of receiving the first light, and a second light-receiving unit capable of receiving the second light. A robot control step that controls the operation of the transport robot, The robot control step involves operating the transport robot to search for a light-shielding point in which at least a portion of the first light received by the first light-receiving unit and at least a portion of the second light received by the second light-receiving unit are blocked by a predetermined marker. A marker position calculation step, which calculates the position of the predetermined marker based on the position of the transport robot at the light-shielding point searched in the search step, The step includes calculating the target position based on the position of the predetermined marker calculated in the marker position calculation step, The search step involves, in the robot control step, repeatedly moving the transport robot in a straight line towards the predetermined marker and rotating the transport robot in a specific direction to search for the light-shielding point. Target position calculation method.

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