Robot control device and installation determination method of object

Abstract

To provide a robot control device capable of determining whether or not an object is installed at an appropriate target position, and provide an installation determination method of the object.SOLUTION: A robot control device 100 comprises: detection means 120 of detecting one part of an arc shape of an object and a part of installation parts to which the object is installed by operating a robot 10 by robot control means 110 by a sensor held by a robot 10 at a plurality of times; first center position calculation means 130 of calculating a first center position (W0) as a center point of the object on the basis of a plurality of positions (WP1 to WP3) of the object to be detected; second center position calculation means 140 of calculating a second center position (S0) as a center point of the installation part on the basis of a plurality of positions (SP1 to SP3) of the installation part to be detected; and deviation determination means 150 of determining a deviation of the object and the installation part on the basis of the first center position (W0) and the second center position (S0).SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a robot control device and a method for determining placement of an object. [Background technology]

[0002] 2. Description of the Related Art In recent years, many robots have come into widespread use in the industrial world. The robots are used, for example, in the assembly, welding, and transportation of electronic and mechanical parts, and are contributing to the efficiency and automation of factory production lines.

[0003] Transport robots used in semiconductor manufacturing equipment to transport wafers require teaching to transport the wafer to the appropriate position, but the accuracy of this teaching depends on the knowledge and skill of the operator. Also, there are cases where space saving is required to the extent that there is not enough space for the operator to work, so efforts are being made to automate this teaching process.

[0004] For example, in Patent Document 1, a substrate-type jig provided with three optical sensors is held by a hand, and the substrate holding part is rotated to form a circular rotation locus of a mark provided in advance on the substrate holding part.Then, a technique is disclosed in which the relative position of the hand to the substrate holding part in a plan view is calculated based on the relative positions to the rotation loci obtained from the three optical sensors.

[0005] In this way, a technique is known in which three optical sensors are used to grasp the positional relationship between the robot and a target position, as well as the surrounding environment, such as obstacles, and transport an object appropriately to the target position. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2022-148237 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the object is transported to the target position by the robot, it is not confirmed whether the object is actually placed appropriately at the target position.

[0008] For example, when an object is transferred to a stage, it is difficult for an operator to visually check with accuracy of less than a millimeter whether the object is properly set so that its center coincides with the center of the stage, which is the target position. In addition, in a space-saving environment where there is not enough space to work, or in a dark place such as a process chamber, there is also the problem that the operator cannot check in the first place.

[0009] Therefore, an object of the present invention is to provide a robot control device and an object placement determination method that are capable of determining whether an object is appropriately placed at a target position. [Means for solving the problem]

[0010] A robot control device according to one embodiment of the present invention is a robot control device that controls the operation of a robot, and includes: a robot control means for operating the robot; a detection means for detecting, by operating the robot using the robot control means, a part of an object, at least a part of which constitutes an arc shape, and a part of an installation section, at least a part of which constitutes the arc shape on which the object is installed, multiple times using a sensor held by the robot; a first center position calculation means for calculating a first center position, which is the center point of the object, based on the multiple positions of the arc shape of the object detected by the detection means; a second center position calculation means for calculating a second center position, which is the center point of the installation section, based on the multiple positions of the arc shape of the installation section detected by the detection means; and a deviation determination means for determining a deviation between the object and the installation section based on the first center position and the second center position.

[0011] According to this aspect, the detection means detects a part of the arc shape of the object and a part of the arc shape of the installation section on which the object is installed multiple times using a sensor held by the robot. The first center position calculation means calculates a first center position that is the center point of the object based on the multiple positions of the object detected by the detection means, and the second center position calculation means calculates a second center position that is the center point of the installation section based on the multiple positions of the installation section detected by the detection means. Then, the deviation determination means determines the deviation between the object and the installation section based on the first center position and the second center position, and as a result, it can determine whether the object is appropriately installed in the target position.

[0012] In the above aspect, the first center position calculation means may calculate the first center position based on at least three positions in the arc shape of the object detected by the detection means.

[0013] According to this aspect, the first center position calculation means can uniquely draw a circle around the object based on at least three positions of the object detected by the detection means, thereby calculating the center position of the object.

[0014] In the above aspect, the second center position calculation means may calculate the second center position based on at least three positions in the arc shape of the installation portion detected by the detection means.

[0015] According to this aspect, the second center position calculation means can uniquely draw a circle of the installation portion based on at least three positions of the installation portion detected by the detection means, and therefore can calculate the center position of the installation portion.

[0016] In the above aspect, the second center position calculation means may calculate the second center position based on at least two positions in the arc shape of the installation portion detected by the detection means and a diameter of a circle configured to partially include the arc shape of the installation portion.

[0017] According to this aspect, the second center position calculation means draws a circle of the installation part based on at least two positions of the installation part detected by the detection means and the diameter of the installation part, thereby reducing the time required to detect the installation part.

[0018] In the above aspect, the detection means may detect a part of the arc shape of the object and a part of the arc shape of the installation part multiple times using a sensor held by the robot, by operating the robot so that the sensor moves in one direction using the robot control means.

[0019] According to this aspect, the detection means causes the robot to operate in such a way that the sensor moves in one direction via the robot control means, thereby causing the sensor to detect the object and the installation portion multiple times, so that it is possible to determine with a simple operation whether the object is properly installed at the target position.

[0020] A method for determining the placement of an object according to one embodiment of the present invention is a method for determining the placement of an object executed by a robot control device that controls the operation of a robot, and includes a robot control step for operating the robot, a detection step for detecting, by a sensor held by the robot, multiple times a part of an object, at least a part of which constitutes an arc shape, and a part of an installation section, at least a part of which constitutes the arc shape on which the object is installed, by operating the robot in the robot control step, a first center position calculation step for calculating a first center position, which is the center point of the object, based on the multiple positions of the arc shape of the object detected in the detection step, a second center position calculation step for calculating a second center position, which is the center point of the installation section, based on the multiple positions of the arc shape of the installation section detected in the detection step, and a misalignment determination step for determining a misalignment between the object and the installation section based on the first center position and the second center position.

[0021] According to this aspect, in the detection step, a part of the arc shape of the object and a part of the arc shape of the installation section on which the object is installed are each detected multiple times by a sensor held by the robot. In the first center position calculation step, a first center position which is the center point of the object is calculated based on the multiple positions of the object detected in the detection step, and in the second center position calculation step, a second center position which is the center point of the installation section is calculated based on the multiple positions of the installation section detected in the detection step. Then, in the deviation determination step, a deviation between the object and the installation section is determined based on the first center position and the second center position, and as a result, it is possible to determine whether the object is appropriately installed in the target position. Effect of the Invention

[0022] According to the present invention, it is possible to provide a robot control device and an object placement determination method capable of determining whether an object is appropriately placed at a target position. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic diagram showing a system configuration of a transfer robot system 1 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing how the transfer robot 10 operates in a clean environment. [Diagram 3] 1 is a diagram showing a state in which a sensor device 20 is held by a hand 11 of a transfer robot 10. FIG. [Figure 4] 1 is a functional block diagram showing each function of a robot control device 100 according to an embodiment of the present invention. [Diagram 5] 13 is a diagram showing how the center position of a circular object 99 is grasped using a moving sensor 80. FIG. [Figure 6] 1 is a diagram showing how the hand 11, holding the sensor device 20, moves toward the stage S on which the wafer W is placed. [Figure 7]13 is a diagram showing how the sensor device 20 held by the hand 11 detects the stage S and the wafer W by passing above the stage S and the wafer W. FIG. [Figure 8A] 1 is a diagram showing how the edge of a wafer W is detected by optical sensors 21 and 22 in a sensor device 20 to grasp the center position of the wafer W. FIG. [Figure 8B] 13 is a diagram showing how the edge of the stage S is detected by the optical sensors 21 and 22 in the sensor device 20 to grasp the center position of the stage S. FIG. [Figure 9] 10 is a flowchart showing the process flow of an object installation determination method M100 executed by a robot control device 100 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings. Note that the embodiment described below is merely a specific example for carrying out the present invention, and is not intended to limit the interpretation of the present invention. In addition, in order to facilitate understanding of the description, the same reference numerals are used as far as possible for the same components in each drawing, and duplicated descriptions may be omitted.

[0025] <One embodiment> [Transport robot system configuration] 1 is a schematic diagram showing a system configuration of a transfer robot system 1 according to an embodiment of the present invention. As shown in FIG. 1, the transfer robot system 1 includes a robot control device 100 and a transfer robot 10.

[0026] The transport robot 10 is, for example, a horizontal articulated robot intended for transporting wafers, and is a clean transport robot used for transport in clean environments in the manufacture of semiconductor devices and flat panel displays, the medical and food industries, etc. In this embodiment, the transport robot 10 is, for example, of a two-axis or three-axis cylindrical coordinate type, and has a hand 11 as an end effector, and a wafer (object) is held and transported by the hand 11, as an example.

[0027] The robot control device 100 is a device that controls the operation of the transport robot 10. For example, the robot control device 100 is connected to an operating device (not shown) such as a teach pendant, and can acquire operation instruction information inputted in the operating device. Based on the operation instruction information, the robot control device 100 operates each axis of the transport robot 10 as well as the arms and hands 11 in order to start and stop the transport robot 10, and to pick up, transport and set down an object.

[0028] An operating device such as a teach pendant accepts input from an operator regarding operation instruction information for the transport robot 10, which is related to the transport work of transporting an object. Typically, an operator inputs appropriate instruction information using an operating device such as a teach pendant, for example, for starting and stopping the transport robot 10, further, settings for the transport robot 10, operations of the arms and hands 11, registration of teaching points, and the like.

[0029] Furthermore, regarding the registration of teaching points, teaching points on the operation path may be automatically registered by automatic teaching, instead of the operator sequentially registering the teaching points on the operation path using an operating device such as a teach pendant while operating the transport robot 10. Such automatic teaching is effective, for example, in an environment or situation where the intrusion space (work space) of the operator cannot be sufficiently secured.

[0030] [Wafer transportation] Fig. 2 is a schematic diagram showing the operation of a transfer robot 10 in a clean environment. As shown in Fig. 2, the transfer robot 10 installed in a working space WS transfers a wafer W held by a hand 11 to each of stages S1 to S3 (hereinafter, sometimes collectively referred to as "stage S") in a process chamber in a vacuum environment.

[0031] Specifically, the transfer robot 10 operates the arms and hands 11 based on operation instruction information from the robot control device 100 to pick up the wafer W and transfer it to the stage S as the transfer destination.

[0032] Here, the target position to which the wafer W is transported and set is, for example, the center of the stage S, and it is preferable to set the wafer W at the center of the stage S with high accuracy, and the robot control device 100 actually transports the wafer W and sets it at the target position, that is, the center of the stage S, based on the teaching data. Then, after setting the wafer W at the target position, the robot control device 100 determines, for example, by using a sensor device, whether the wafer W is set at the target position, that is, the center of the stage S.

[0033] [Sensor device configuration] The sensor device is a device that includes an optical sensor and can be grasped, held, or attached to the hand 11 of the transport robot 10. Fig. 3 is a diagram showing a state in which the sensor device 20 is held by the hand 11 of the transport robot 10. As shown in Fig. 3, the hand 11 holds the sensor device 20 having two optical sensors 21 and 22.

[0034] The two optical sensors 21 and 22 are attached to the rear surface of the sensor device 20, and are reflective optical sensors capable of calculating distance by receiving reflected light of light emitted downward from a light source.

[0035] Since the sensor device 20 is placed on the hand 11, the two optical sensors 21 and 22 are attached near the outer periphery (edge) of the sensor device 20 so that the light emitted downward is not blocked by the hand 11. In other words, the hand 11 holds the sensor device 20 so as to avoid the area where the two optical sensors 21 and 22 are attached.

[0036] The sensor device 20 may also be equipped with a control unit and a communication unit, and the two optical sensors 21 and 22 control the light emitted from the light source, receive reflected light, and notify information thereabout, for example, to the robot control device 100.

[0037] When determining whether the wafer W is placed at the center of the stage S, which is the target position, a sensor device 20 held by the hand 11 of the transport robot 10 is used to grasp the positional relationship between the stage S and the wafer W placed on the stage S, as described below.

[0038] The determination as to whether the wafer W is placed at the center of the stage S may be performed each time a wafer W is transported, but considering the operation time, it may actually be performed every predetermined number of wafers, every predetermined time, for each type of wafer transported, immediately after the start or end of the operation, or when some abnormality is detected. For example, immediately after the start of the operation of the day or at a predetermined time, the sensor device 20 may be held by the hand 11 of the transport robot 10 to determine whether the wafer W placed on the stage S is placed at the center of the stage S. This determination will be described in detail below.

[0039] [Robot control device configuration] FIG. 4 is a functional block diagram showing each function of a robot control device 100 according to an embodiment of the present invention. As shown in FIG. 4, the robot control device 100 includes a robot control unit 110, a detection unit 120, a first center position calculation unit 130, a second center position calculation unit 140, and a deviation determination unit 150, and controls the operation of the transfer robot 10. The robot control device 100 detects the stage S and the wafer W placed on the stage S by the two optical sensors 21 and 22 while moving the hand 11 holding the sensor device 20 (two optical sensors 21 and 22). Then, the robot control device 100 grasps the positional relationship between the stage S and the wafer W based on the detection result, and determines whether the wafer W placed on the stage S is placed with a deviation from the target position.

[0040] 1, the robot control device 100 is connected to the transfer robot 10, and further has many functions for performing various controls and processes based on operation instruction information from an operating device such as a teach pendant, automatic control (automatic teaching), etc. Here, the robot control device 100 is mainly shown to have a wafer W placement determination function for determining whether or not the wafer W placed on the stage S is placed in a misaligned position with respect to the target position, but it also has other configurations and functions.

[0041] The robot control means 110 operates the transfer robot 10. For example, the transfer robot 10 holds a sensor device 20 in a hand 11, and the robot control means 110 operates each axis of the transfer robot 10, as well as the arm and hand 11, so that two optical sensors 21 and 22 attached to the sensor device 20 pass above a stage S and a wafer W placed on the stage S.

[0042] The detection means 120 operates the transport robot 10 by the robot control means 110, and detects a part of the arc shape of the wafer W, at least a part of which constitutes an arc shape, and a part of the arc shape of the stage S, at least a part of which constitutes an arc shape on which the wafer W is placed, multiple times using the sensor device 20 (two optical sensors 21 and 22) held by the hand 11 of the transport robot 10. For example, the two optical sensors 21 and 22 provided on the back surface of the sensor device 20 emit light downward, and when a part of the arc shape of the wafer W and a part of the arc shape of the stage S reach the position of the emitted light, the reflected light received by the two optical sensors 21 and 22 changes. The detection means 120 acquires information from the sensor device 20 that the part of the arc shape of the wafer W and the part of the arc shape of the stage S have been detected by the two optical sensors 21 and 22.

[0043] It should be noted that the two optical sensors 21 and 22 detect a portion of the arc shape of the wafer W and a portion of the arc shape of the stage S multiple times, and each time the two optical sensors 21 and 22 detect a different position of the arc shape of the wafer W and the arc shape of the stage S, respectively.

[0044] The first center position calculation means 130 calculates a first center position, which is the center point of the wafer W, based on multiple positions in the arc shape of the wafer W detected by the detection means 120. For example, the first center position calculation means 130 calculates multiple positions (robot coordinate system) in the detected arc shape of the wafer W based on the positions and postures of the transfer robot 10 when a part of the arc shape of the wafer W is detected multiple times by the two optical sensors 21 and 22. Then, the first center position calculation means 130 calculates the center of the circle based on the multiple positions (robot coordinate system) in the arc shape of the wafer W as the first center position, which is the center point of the wafer W.

[0045] The second center position calculation means 140 calculates a second center position, which is the center point of the stage S, based on multiple positions in the arc shape of the stage S detected by the detection means 120. For example, the second center position calculation means 140 calculates multiple positions (robot coordinate system) in the detected arc shape of the stage based on the position and posture of the transport robot 10 when a part of the arc shape of the stage S is detected multiple times by the two optical sensors 21 and 22. Then, the second center position calculation means 140 calculates the center of the circular shape based on the multiple positions (robot coordinate system) in the arc shape of the stage S as the second center position, which is the center point of the stage S.

[0046] The deviation determination means 150 determines the deviation between the wafer W and the stage S based on the first center position calculated by the first center position calculation means 130 and the second center position calculated by the second center position calculation means 140. For example, when the target position for placing the wafer W is the center position of the stage S, the deviation determination means 150 can determine whether the wafer W is appropriately placed at the center position of the stage S, which is the target position, by comparing the center position of the wafer W placed on the stage S with the center position of the stage S. Specifically, the deviation determination means 150 may determine that the wafer W is placed deviated from the stage S, which is the target position, if the first center position calculated by the first center position calculation means 130 as the center point of the wafer W and the second center position calculated by the second center position calculation means 140 as the center point of the stage S deviate by a predetermined threshold value or more. In other words, the deviation determination means 150 determines that the wafer W is not appropriately placed at the target position.

[0047] In this way, the robot control device 100 holds the sensor device 20 using the hand 11 of the transport robot 10 and detects the wafer W placed on the stage S and the stage S using the two optical sensors 21 and 22, thereby appropriately calculating the center positions of the wafer W and the stage S and determining whether the wafer W is appropriately placed on the target position, the stage S.

[0048] The following provides a more detailed explanation of how to determine whether or not the wafer W is properly placed on the stage S based on multiple positions of the arc shape of the wafer W and stage S detected by the two optical sensors 21 and 22.

[0049] [Principle of positioning using reflective sensors] First, the positional relationship between a moving sensor and a target object having a circular shape will be described. Fig. 5 is a diagram showing how the center position of a circular object 99 is grasped using a moving sensor 80. As shown in Fig. 5, the sensor 80 (corresponding to the optical sensor 21 or 22) moves toward the circular object 99 and detects positions 81, 82, and 83 of the circular shape (arc shape) of the object 99.

[0050] Specifically, the sensor 80 approaches the object 99 and records a detection position 81 when a part of the arc of the object 99 is detected by the sensor 80 (first time). Next, the sensor 80 approaches the object 99 from a position different from the first time and records a detection position 82 when a part of the arc of the object 99 (a place different from the first time) is detected by the sensor 80 (second time). Furthermore, the sensor 80 approaches the object 99 from a position different from the first and second times and records a detection position 83 when a part of the arc of the object 99 (a place different from the first and second times) is detected by the sensor 80 (third time).

[0051] In this way, when the detection positions 81, 82, and 83 are obtained, a circle 80C including these three points can be uniquely drawn. Then, the center position of the circle 80C can be calculated as the center position 90 of the object 99.

[0052] [Wafer and stage shape] In order to utilize the principle regarding the positional relationship between the sensor and the object described using Figure 5, the object, which is the wafer W transported by the transport robot 10, and the stage S, which is the target position for placing the wafer W, form part of a circle (arc shape).

[0053] [Optical sensor for wafer and stage detection] 6 is a diagram showing how the hand 11, holding the sensor device 20, moves toward the stage S on which the wafer W is placed. As shown in Fig. 6, the hand 11 approaches the stage S, and the sensor device 20 held by the hand 11 moves above the stage S and the wafer W placed on the stage S. Then, two optical sensors 21 and 22 provided on the sensor device 20 detect the stage S and the wafer W.

[0054] 7 is a diagram showing how the sensor device 20 held by the hand 11 detects the stage S and the wafer W by passing above the stage S and the wafer W. As shown in Fig. 7, the sensor device 20 held by the hand 11 passes above the stage S and the wafer W placed on the stage S, so that the two optical sensors 21 and 22 detect the edges of the stage S and the wafer W.

[0055] Specifically, first, the optical sensor 21 detects a part (edge) of the arc shape on the front side of the stage S (the side toward which the hand 11 moves) (detection position SP1), and then the optical sensor 22 detects the front edge of the stage S (detection position SP2).

[0056] As the hand 11 moves further, the optical sensor 21 detects a part (edge) of the arc shape on the front side of the wafer W (detection position WP1), and the optical sensor 22 detects the front edge of the wafer W (detection position WP2).

[0057] As the hand 11 moves further, the optical sensor 22 can detect part (edge) of the arc shape on the far side of the wafer W (the side through which the hand 11 passes) (detection position WP3), and the optical sensor 22 can detect part (edge) of the arc shape on the far side of the stage S (detection position SP3).

[0058] In this way, as the sensor device 20 held by the hand 11 passes above the stage S and the wafer W, the two optical sensors 21 and 22 detect the edge (detection positions SP1-SP3) of the stage S and the edge (detection positions WP1-WP3) of the wafer W. Then, based on the principle described using Fig. 5, the center position of the stage S can be calculated from the detection positions SP1-SP3, and the center position of the wafer W can be calculated from the detection positions WP1-WP3.

[0059] [Wafer position] 8A is a diagram showing how the optical sensors 21 and 22 in the sensor device 20 detect the edges of the wafer W to determine the center position of the wafer W. As described with reference to FIG. 7, the two optical sensors 21 and 22 detect the edges of the stage S (detection positions SP1 to SP3) and the edges of the wafer W (detection positions WP1 to WP3), but here, elements related to the wafer W are extracted from those and how the center position of the wafer W is determined will be described.

[0060] In state (A), the hand 11 of the transfer robot 10 is moved toward the wafer W placed on the stage S. As the hand 11 approaches the wafer W, the sensor device 20 held by the hand 11 passes above the wafer W, and the edge of the wafer W is detected by the optical sensor 21 provided in the sensor device 20, and the detection position WP1 at that time is recorded (first point).

[0061] The hand 11 is further moved to the (B) state, where the edge of the wafer W is detected by the optical sensor 22 provided in the sensor device 20, and the detected position WP2 at that time is recorded (second point).

[0062] The hand 11 is further moved to the (C) state, where the edge of the wafer W is detected by the optical sensor 22 provided in the sensor device 20, and the detected position WP3 at that time is recorded (third point).

[0063] In this way, when the three detection positions (WP1 to WP3) are obtained, a circle W10 including these three points can be uniquely drawn. Then, the center point of the circle W10 can be calculated as the center position W0 of the wafer W (robot coordinate system).

[0064] [Stage Position] 8B is a diagram showing how the optical sensors 21 and 22 in the sensor device 20 detect the edges of the stage S to determine the center position of the stage S. As described with reference to FIG. 7, the two optical sensors 21 and 22 detect the edges of the stage S (detection positions SP1 to SP3) and the edges of the wafer W (detection positions WP1 to WP3), but here, elements related to the stage S are extracted from those and how the center position of the stage S is determined will be described.

[0065] In state (A), the hand 11 of the transport robot 10 is moved toward the stage S. As the hand 11 approaches the stage S, the sensor device 20 held by the hand 11 passes above the stage S, and the edge of the stage S is detected by the optical sensor 21 provided in the sensor device 20, and the detection position SP1 at that time is recorded (first point).

[0066] The hand 11 is further moved to the (B) state, where the edge of the stage S is detected by the optical sensor 22 provided in the sensor device 20, and the detection position SP2 at that time is recorded (second point).

[0067] The hand 11 is further moved to state (C), where the edge of the stage S is detected by the optical sensor 22 provided in the sensor device 20, and the detection position SP3 at that time is recorded (third point).

[0068] In this way, when the three detection positions (SP1 to SP3) are obtained, a circle S10 including these three points can be uniquely drawn. Then, the center point of the circle S10 can be calculated as the center position S0 of the stage S (robot coordinate system).

[0069] By comparing the center position W0 of the wafer W calculated as described above with the center position S0 of the stage S, it is determined whether or not the wafer W is properly placed on the stage S. For example, if the center position W0 of the wafer W and the center position S0 of the stage S deviate by a predetermined threshold value or more, it may be determined that the wafer W is not properly placed in the center of the stage S and is placed displaced from the target position.

[0070] [Wafer placement judgment method] Next, a method for determining whether or not the wafer W placed on the stage S is properly placed using the two optical sensors 21 and 22 in the sensor device 20 held by the hand 11 will be specifically described in detail.

[0071] 9 is a flowchart showing the process flow of an object installation determination method M100 executed by a robot controller 100 according to one embodiment of the present invention. As shown in FIG 9, the object installation determination method M100 includes steps S110 to S160, and each step is mainly executed by a processor included in the robot controller 100.

[0072] In step S110, the transfer robot 10 (hand 11) is moved (robot control step). As a specific example, the transfer robot 10 holds the sensor device 20 in the hand 11, and the robot control means 110 operates the transfer robot 10 (hand 11) so that the two optical sensors 21 and 22 attached to the sensor device 20 pass above the wafer W placed on the stage S and the stage S.

[0073] In step S120, the two optical sensors 21 and 22 detect the edge of the wafer W or the edge of the stage S (detection step). As a specific example, the sensor device 20 held by the hand 11 passes above the wafer W and the stage S, causing the two optical sensors 21 and 22 to detect the edge of the wafer W or the edge of the stage S.

[0074] In step S130, the detection positions of the edge of the wafer W or the edge of the stage S detected in step S120 are stored (detection position storage step). As a specific example, as described with reference to Figures 7, 8A, and 8B, the edge of the wafer W is detected by the two optical sensors 21 and 22, and the detection positions (WP1 to WP3) at that time are stored in memory, and the edge of the stage S is detected by the two optical sensors 21 and 22, and the detection positions (SP1 to SP3) at that time are stored in memory.

[0075] In step S140, it is determined whether circles can be formed for the wafer W and the stage S, respectively, based on the detection positions saved in step S130. If it is determined that circles can be formed for the wafer W and the stage S, respectively ("Yes" in step S140), the process proceeds to step S150, and if it is determined that circles cannot be formed for the wafer W and the stage S, respectively ("No" in step S140), the process returns to step S110, and steps S110 to S140 are repeated.

[0076] For example, as explained using Figures 5, 8A, and 8B, a circle can be drawn uniquely with three points, but it can also be drawn with two points if the radius or diameter of the circle is known.

[0077] In step S150, the center position W0 of the wafer W and the center position S0 of the stage S are calculated based on the detection positions stored in step S130 (first center position calculation step and second center position calculation step). As a specific example, the first center position calculation means 130 calculates the center position W0 of a circle W10 as the center position of the wafer W, as shown in Fig. 8A, based on the detection positions (WP1 to WP3) of the edge of the wafer W stored in step S130.

[0078] Similarly, the second center position calculation means 140 calculates the center position S0 of the circle S10 as the center position of the stage S, as shown in FIG. 8B, based on the detected positions (SP1 to SP3) of the edge of the stage S stored in step S130.

[0079] In step S160, a misalignment is determined based on the center position W0 of the wafer W and the center position S0 of the stage S calculated in step S150 (misalignment determination step). As a specific example, the misalignment determination means 150 compares the center position W0 of the wafer W with the center position S0 of the stage S, and if there is a misalignment of a predetermined threshold or more, determines that the wafer W is placed misaligned with respect to the target position of the stage S.

[0080] If it is determined that the wafer W is misaligned with respect to the target position of the stage S, a notice to that effect may be sent, and then the robot teaching may be redone, or the robot teaching information may be automatically corrected according to the amount of misalignment. Also, threshold values ​​may be set in stages, and normal range, allowable range, danger range, installation misalignment, and the like may be notified according to the amount of misalignment, and further, a prediction of the danger range and installation misalignment may be made based on the history.

[0081] As described above, according to the robot control device 100 and the object placement determination method M100 according to an embodiment of the present invention, the sensor device 20 is held by the hand 11 of the transport robot 10, and the robot control means 110 operates the transport robot 10 so that the two optical sensors 21 and 22 attached to the sensor device 20 pass above the stage S and the wafer W placed on the stage S. The detection means 120 detects the edge of the wafer W and the edge of the stage S multiple times, and the first center position calculation means 130 calculates the center position (W0) of the wafer W from the circle W10 of the wafer W drawn based on the multiple detection positions (WP1 to WP3) of the edge of the wafer W detected by the detection means 120. Similarly, the second center position calculation means 140 calculates the center position (S0) of the stage S from the circle S10 of the stage S drawn based on the multiple detection positions (SP1 to SP3) of the edge of the stage S detected by the detection means 120. Then, the misalignment determination means 150 determines the misalignment between the wafer W and the stage S by comparing the center position (W0) of the wafer W with the center position (S0) of the stage S. As a result, it is possible to determine whether the wafer W has been appropriately placed at the center position of the stage S, which is the target position.

[0082] In this embodiment, as described using Figures 8A and 8B, the detection means 120 detects three points on the edge of the wafer W and the edge of the stage S, and the first center position calculation means 130 and the second center position calculation means 140 calculate the center position W0 of the circle W10 and the center position S0 of the circle S10, by drawing a circle W10 from the detection positions (WP1 to WP3) and drawing a circle S10 from the detection positions (SP1 to SP3), respectively; however, this is not limited to this.

[0083] For example, if the radius (diameter) of the circle constituting the wafer W and / or stage S is known in advance (as a fixed value), two points can be detected by the detection means 120, and two different circles can be drawn from the two points. Then, one of the two different circles can be selected based on the positional relationship (the moving direction of the hand 11) between the two optical sensors 21 and 22 provided in the sensor device 20 and the wafer W and / or stage S. In other words, if the detection means 120 detects two points on each of the edges of the wafer W and / or stage S, the center position of the wafer W and / or stage S can be calculated.

[0084] In the semiconductor manufacturing device (facility), the radius (diameter) of the stage S is a fixed value, and the design (measurement) precision is high, so that the radius (diameter) can be used as a highly reliable value. That is, the center position of the stage S can be appropriately calculated based on two detection positions of the edge of the stage S detected by the detection means 120 and the radius (diameter) of the stage S, which is known in advance. In other words, if two points are detected instead of three points on the edge of the stage S, a circle S10 of the stage S can be drawn based on the detection positions of the two points, and the center position S0 of the stage S can be calculated with high precision.

[0085] On the other hand, although the wafer W has a high degree of circularity, the radius (diameter) tolerance is large, so it is preferable to appropriately calculate the center position of the wafer W for each wafer W based on the three detection positions of the edge of the wafer W detected by the detection means 120.

[0086] In addition, in this embodiment, the sensor device 20 is provided with two optical sensors 21, 22, but this is not limited to this. For example, the optical sensor may be one, or three or more, and the required number of optical sensors may be provided depending on the detection of the edges of the wafer W and stage S.

[0087] Furthermore, in this embodiment, the sensor device 20 is circular, but is not limited thereto, and may be rectangular, triangular, or other polygonal. Specifically, it is sufficient that the sensor device is disposed in a manner that the optical sensor provided in the sensor device is not blocked by the robot hand when the sensor device is held by the robot hand according to the shape of the robot hand.

[0088] Furthermore, the sensor device 20 is not limited to being placed and held by a robot hand from below, but may be held by being sandwiched from both sides by the robot hands, for example.

[0089] Furthermore, instead of a configuration in which the sensor device is held by the robot hand, a configuration in which the sensor is attached to the robot hand (part of the robot) may be used as long as the edges of the wafer W and the stage S can be detected. A sensor device provided with a sensor or a sensor may be installed on the robot hand (part of the robot) using, for example, a magnet or a suction cup that can be easily attached and detached to the robot hand (part of the robot).

[0090] In this embodiment, the optical sensors 21 and 22 are provided at the rear of the sensor device 20 with respect to the moving direction of the hand 11, but the present invention is not limited to this and may be provided depending on the shape and moving direction of the hand 11, and further the configuration of the stage S and its surroundings. For example, when the space on the other side of the stage S with respect to the moving direction of the hand 11 is limited, the optical sensors 21 and 22 may be provided forward with respect to the moving direction of the hand 11.

[0091] Furthermore, multiple edges of the wafer W and stage S are detected, and the detection positions are preferably as far apart as possible to reduce errors in the circles of the wafer W and stage S drawn based on those detection positions, and as a result, the central positions of the wafer W and stage S can be calculated with high accuracy. For example, when two optical sensors 21 and 22 are provided in the sensor device 20, it is advisable to provide them as far apart as possible on both sides.

[0092] In addition, in this embodiment, the hand 11 moves in one direction to detect multiple edges of the wafer W and multiple edges of the stage S, but this is not limited to this. If multiple edges of the wafer W and multiple edges of the stage S are detected, for example, after detecting the edge of the wafer W and the edge of the stage S, the hand 11 may retreat once and approach the direction of the wafer W and the stage S at a different angle to detect another position of the edge of the wafer W and the edge of the stage S.

[0093] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those shown as examples and can be changed as appropriate. In addition, configurations shown in different embodiments can be partially substituted or combined with each other. [Explanation of symbols]

[0094] 1...Transport robot system, 10...Transport robot, 11...Hand, 20...Sensor device, 21, 22...Optical sensor, 80...Sensor, 81-83, WP1-WP3, SP1-SP3...Detection position, 80C, W10, S10...Circle, 90, W0, S0...Center position, 99...Object, 100...Robot control device, 110...Robot control means, 120...Detection means, 130...First center position calculation means, 140...Second center position calculation means, 150...Displacement determination means, WS...Work space, W...Wafer, S, S1-S3...Stage, M100...Object placement determination method, S110-S160...Each step of the object placement determination method

Claims

1. A robot control device for controlling an operation of a robot, A robot control means for operating the robot; a detection means for detecting, by operating the robot using the robot control means, a part of an object that at least a part of which forms an arc shape, and a part of an installation section that at least a part of which forms an arc shape on which the object is installed, multiple times using a sensor held by the robot; a first center position calculation means for calculating a first center position that is a center point of the object based on a plurality of positions in the arc shape of the object detected by the detection means; a second center position calculation means for calculating a second center position, which is a center point of the installation portion, based on a plurality of positions in the arc shape of the installation portion detected by the detection means; a deviation determination means for determining a deviation between the object and the installation portion based on the first center position and the second center position, Robot control device.

2. The first center position calculation means calculates the first center position based on at least three positions in the arc shape of the object detected by the detection means. The robot control device according to claim 1 .

3. the second center position calculation means calculates the second center position based on at least three positions in the arc shape of the installation portion detected by the detection means. The robot control device according to claim 1 .

4. the second center position calculation means calculates the second center position based on at least two positions in the arc shape of the installation portion detected by the detection means and a diameter of a circle configured to include a part of the arc shape of the installation portion. The robot control device according to claim 1 .

5. the detection means detects a part of the arc shape of the object and a part of the arc shape of the installation portion multiple times using a sensor held by the robot by operating the robot so that the sensor moves in one direction using the robot control means; The robot control device according to claim 1 .

6. A method for determining whether an object is placed on a robot, the method comprising: a robot control step of operating the robot; a detection step in which, by operating the robot in the robot control step, a part of an object that at least a part of which forms an arc shape and a part of an installation part that at least a part of which forms an arc shape on which the object is installed are detected a plurality of times by a sensor held by the robot; a first center position calculation step of calculating a first center position that is a center point of the object based on a plurality of positions on the arc shape of the object detected in the detection step; a second center position calculation step of calculating a second center position that is a center point of the installation portion based on a plurality of positions on the arc shape of the installation portion detected in the detection step; and determining a deviation between the object and the installation section based on the first center position and the second center position. Method for determining installation of object.

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