JP2015005682A - Transfer robot and transfer method of disk-shaped transfer object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering in detection accuracy due to variation in scan timing of a sensor for detecting a wafer mounted on a hand, and accurately determine the difference between the position of the wafer mounted on the hand and a normal mounting position to securely transfer the wafer.SOLUTION: A transfer robot has: peripheral position detection means for detecting three peripheral positions in a wafer 7 mounted on a hand 23 which is in a stopped state at a transfer start position by liner sensors 6L, 6C, 6R, respectively; center position calculation means for calculating the center position of the wafer 7 on the basis of the position information of the respective liner sensors 6L, 6C, 6R on the orthogonal coordinate system and the peripheral position of the wafer 7; displacement calculation means for calculating the difference between the reference center position and the calculated center position of the wafer 7; and operation instruction generation means for generating an operation instruction to specify an operation amount of a transfer driving mechanism 1 on the basis of the calculated difference. On the basis of the operation instruction, operation of the transfer driving mechanism 1 is controlled.

Description

  The present invention relates to a transport robot that transports a disk-shaped transport target such as a wafer, and a method for transporting a disk-shaped transport target using the transport robot.

  Conventionally, a disk on a hand is operated by operating a transport driving mechanism including the hand in a state where a disk-shaped transport object such as a wafer is placed and held on a transport hand (hereinafter abbreviated as “hand”). 2. Description of the Related Art A transfer robot configured to be able to transfer an object to be transferred to a predetermined transfer position (transfer target position) is known. For example, when the object to be transferred is a wafer, the wafer is manufactured in a precise disk shape (however, notches such as notches and orientation flats may be formed), so there is no error for each transferred wafer. It is considered a thing. In such a transport robot, if the disc-shaped transport object is placed at a regular placement position on the hand, the transport drive mechanism performs an appropriate operation so that the disc-shaped transport object on the hand is moved. It can be transported to a regular transfer position.

  However, if the disk-shaped transport object is placed at a position slightly displaced from the regular placement position on the hand, the disk-shaped transport object is moved to a position displaced from the regular transfer position according to the amount of displacement. The object will be transported.

  Therefore, the present applicant obtains the difference between the position of the disc-shaped conveyance object placed and held on the hand of the conveyance robot and the normal placement position, and appropriately controls the operation amount of the conveyance drive mechanism according to the difference. Therefore, as a transport robot capable of transporting a disk-shaped transport target object to a regular transport target position, the configuration shown in Patent Document 1 below has been invented and a patent application has already been filed.

  In the transport robot shown in Patent Document 1, the movement of the disc-shaped transport target placed on the hand is configured to be detected by a single sensor, and the passage sensed by the sensor when the disc-shaped transport target passes the sensor. Placed at the normal placement position on the hand and the passing distance in the first axis direction (Y-axis direction on the Cartesian coordinate system) with respect to the sensor of the disk-shaped conveyance object obtained based on the start point and the passage end point A Cartesian coordinate system of the placement position of the disc-shaped transport object on the hand and the normal placement position using the distance that the held disk-shaped transport object passes the sensor and the radius of the disk-shaped transport object. The above difference is obtained, calculated by converting the difference into a correction value in the robot movement polar coordinate system of the pivot axis and the arm, and outputting the correction value.

JP 2012-74469 A

  However, in the invention described in Patent Document 1, it is essential that the disk-shaped transported object placed on the hand is passed through the sensor as the hand moves. Therefore, there is a delay time from when the sensor detects the peripheral position of the disc-shaped transported object until the peripheral position data is taken in, and there may be an error in the true value of the peripheral position due to the moving speed of the disc-shaped transported object. .

  When the hand is moved at a relatively slow constant speed, the above errors do not pose a major problem. However, the hand is moved at a high speed or the moving speed of the hand is accelerated while the object is being transported in a disk shape. Is transported to the transport target position, the transport speed at the time when the disc-shaped transport object placed on the hand finishes passing through the sensor is higher than the transport speed at the time when the disc-shaped transport object starts passing through the sensor. The possibility that the detection accuracy at the time of passing through the sensor is lower than the detection accuracy at the time of starting to pass through the sensor due to variations in the sensor scan timing cannot be excluded. In particular, as the moving speed of the hand is set faster to improve the transport efficiency of the disk-shaped transport object, the detected value (the disk shape detected by the sensor) with respect to the actual peripheral position (true value) of the disk-shaped transport object It is expected that the error in the peripheral position of the conveyance object will increase.

  In addition, when the center position of the disc-shaped transport object is calculated by using the diameter size of the disc-shaped transport object as a known value, an error in the diameter size in the disc-shaped transport object that is strictly manufactured is individual. Although the actual diameter size is different from the value used as a known value by, for example, expansion processing, the center position of the disc-shaped transport object calculated using the known diameter size is actually It will deviate from the center position (true value) of the disk-shaped transport object.

  Furthermore, when the peripheral position of the disc-shaped conveyance object is indirectly detected by an encoder attached to a drive source (such as a motor) that drives the conveyance drive mechanism, the drive source generated at the time of operation and the tip of the conveyance drive mechanism It is also conceivable that an error in the detection value (disc-shaped transport object) with respect to the true value occurs due to the influence of elastic deformation of a plurality of transmission mechanisms (belts and gears) interposed between the hand and the hand. Also in this case, the center position of the disk-shaped transport object calculated based on the position detection value including the error is also a value deviated from the true value (actual center position of the disk transport object).

  When such a situation occurs, it is impossible to accurately calculate the center position of the disk-shaped transport object that is actually transported, and the correction value in the robot motion polar coordinate system obtained from the calculated value including the error is used. The amount of deviation from the reference placement position (reference grip position) of the disc-shaped transport target placed and held (gripped) on the hand by operating the transport drive mechanism based on the correction value is calculated. By correcting, the accuracy of transporting to a predetermined transport target position decreases.

  The present invention has been made paying attention to such a problem, and the main purpose is not to be affected by the transfer speed of the disk-shaped transfer object by the hand, and the diameter size of the disk-shaped transfer object. Without using as a known value, the difference between the position of the disc-shaped transport object placed and held on the hand and the normal center position is accurately obtained, and the disc-shaped transport object is more accurately moved to the predetermined transport target position. Another object of the present invention is to provide a transport robot and a disk-shaped transport object transport method that can transport the transport object.

  That is, the present invention includes a transport drive mechanism capable of transporting a disk-shaped transport object on a hand to a predetermined transport target position by moving the hand from a transport start position to a delivery position along a linear movement path, and a transport The present invention relates to a transfer robot including a control unit that controls the operation of a drive mechanism.

  Here, the disk-shaped conveyance object may be a disk-shaped object, and examples thereof include a semiconductor wafer and a liquid crystal panel. Further, the control unit may be built in or attached to the transport driving mechanism, or may be provided outside the transport driving mechanism. As the transport drive mechanism, the hand is configured to be able to move back and forth linearly along two orthogonal axes, or the base end of the arm is configured to be pivotable around the pivot axis and provided at the distal end of the arm And a hand configured to be able to move forward and backward.

  The transfer robot according to the present invention is a disk-shaped transfer target on the hand if the hand is moved from the transfer start position to the delivery position in a state where the disk-shaped transfer target is mounted at a normal mounting position on the hand. An object can be accurately conveyed to a predetermined conveyance target position. This means that if the hand is moved from the transport start position to the delivery position in a state where the disc-shaped transport object is placed at a position shifted from the normal placement position on the hand, This means that the object to be transported is transported to a position moved according to the amount of displacement of the placement position with respect to a predetermined transport target position. In the transfer robot according to the present invention, even when the disk-shaped transfer object is placed at a position deviated from the normal placement position on the hand, the disk-like transfer object on the hand is set to a predetermined value. The structure described below is adopted so that it can be accurately transported to the transport target position.

  In other words, the transport robot according to the present invention includes, as the control unit, a peripheral position detection unit, a center position calculation unit, a displacement amount calculation unit, and an operation command generation unit, and an operation generated by the operation command generation unit. The present invention is characterized in that a configuration that controls the operation of the transport drive mechanism based on a command is applied.

  Specifically, the peripheral position detection means detects three or more different peripheral positions of the disc-shaped transport object placed on the stopped hand at the transport start position by three or more linear sensors. is there. Further, the center position calculation means, when the orthogonal coordinate system is defined by the first axis that is the normal movement path of the hand and the second axis that is orthogonal to the first axis in the horizontal plane including the first axis, The center position of the disc-shaped conveyance object is calculated using the linear sensor position information, which is the installation position of each linear sensor on the coordinate system, and the peripheral position detected by the peripheral position detecting means.

  The displacement amount calculating means calculates the reference center position on the Cartesian coordinate system, which is the center position of the disk-shaped transport object when the disk-shaped transport object is placed at the normal placement position on the hand, and the center position calculation. The difference (displacement amount) from the center position of the disk-shaped conveyance object calculated by the means is calculated. Further, the operation command generating means operates the transport driving mechanism necessary for transporting the disc-shaped transport object on the hand to a predetermined transport target position based on the difference (displacement amount) calculated by the displacement amount calculating means. An operation command that defines the quantity is generated.

  In such a transfer robot according to the present invention, at least the peripheral portions of the disc-shaped transfer object placed on the hand that is stopped at the transfer start position are detected by three or more linear sensors, respectively. Based on a plurality of peripheral positions that are detection values and linear sensor position information that is an installation position of each linear sensor, the plurality of peripheral positions and the plurality of linear sensor position information can be defined on a common orthogonal coordinate system. Because it is configured to calculate the center position of the disc-shaped transport object on the Cartesian coordinate system by using what is possible, it is affected by the transport speed of the disk-shaped transport object and the acceleration during transport. The accuracy of detecting the peripheral position of the disc-shaped transport object decreases as the transport speed of the disc-shaped transport object increases, and it is further placed on the hand. Accuracy of calculating the center position of the disc-like object to be transported it is possible to avoid a situation of reduced.

  In the transfer robot of the present invention, the center position of the disk-shaped transfer object on the orthogonal coordinate system is calculated without using the diameter size of the disk-shaped transfer object placed on the hand as a known value. Therefore, the center position of each disk-shaped transport object can be calculated with high accuracy even if it is a disk-shaped transport object having a different diameter size for each individual due to high-temperature processing or the like. Further, since the center position of the disc-shaped transport object is calculated based on the detection values obtained by sensing the peripheral portion of the stopped disk-shaped transport object with three or more linear sensors, the transport drive It is not affected by the elastic deformation of the transmission mechanism that is interposed between the drive source of the mechanism and the hand, and there is no need to consider the effect, and in this respect also, the accuracy of calculating the center position of the disc-shaped conveyance object It contributes to the improvement.

  Thus, with the transfer robot according to the present invention, the center position of the disc-shaped transfer object actually placed on the hand can be calculated more accurately, and the actual placement on the hand is possible. The center position of the disc-shaped transport target object is orthogonal to the reference center position, which is the center position of the disc-shaped transport target object when the disc-shaped transport target object is placed on the regular placement position on the hand. An accurate difference on the coordinate system can be obtained, and an operation command in which the operation amount of the transport drive mechanism is corrected including this difference is generated, and based on this operation command (an operation command including the corrected operation amount) By operating the transport drive mechanism, correct the amount of discrepancy between the center position of the disk-shaped transport object actually placed on the hand and the reference center position, and place it on the hand. Move the object to be transported to the specified transport target position. It can be sent.

  As described above, the transfer robot according to the present invention moves the hand from the transfer start position to the delivery position in a state where the disc-shaped transfer target object is placed at the normal placement position on the hand. A disk-shaped conveyance object can be accurately conveyed to a predetermined conveyance target position. Therefore, when the difference (displacement amount) calculated by the displacement amount calculating means with the above-described configuration is zero, that is, when the disc-shaped transport object is placed at the regular placement position on the hand, the operation command The correction operation amount included in the operation command generated by the generating means is zero, and if the hand is moved from the transfer start position to the delivery position, the disk-shaped transfer object on the hand is accurately transferred to the predetermined transfer target position. can do. On the other hand, when the difference (displacement amount) calculated by the displacement amount calculation means is not zero, that is, when the disc-shaped transport object is placed at a position shifted from the normal placement position on the hand, the operation command By operating the transport drive mechanism based on the correction operation amount included in the motion command generated by the generating means, the disc-shaped transport target on the hand can be transported to a predetermined transport target position. In the latter case, the position of the hand when it has been transported to the predetermined transport target position is a position moved by a correction operation amount with respect to the delivery position in the former case.

  Based on the above, the transfer robot according to the present invention is configured so that the operation command generated by the operation command generating means (the operation of the transfer drive mechanism necessary for transferring the disc-shaped transfer object on the hand to a predetermined transfer target position). This is a command that regulates the amount, and when a disc-shaped object to be transported is placed at a position deviated from the normal placement position on the hand, it is actually on the hand based on the motion command including the compensation motion amount). For example, after the hand is moved from the transport start position to the delivery position, the amount of deviation between the center position of the disc-shaped transport object placed on the base and the reference center position is corrected by the operation of the transport drive mechanism. It does not exclude the configuration.

  However, with such a configuration, after moving the hand from the transfer start position to the delivery position, the hand is operated with a small amount of correction, so it is easily affected by lost motion and hysteresis of the mechanical system, There may be a problem that the tact of minutes is excessive.

  Therefore, in the transfer robot of the present invention, the operation command is generated using the center position of the disc-shaped transfer object calculated based on the information on the peripheral position of the disk-shaped transfer object on the hand at the transfer start position. The control unit generates an operation command for the transport drive mechanism at a time before the hand moves the hand from the transport start position toward the delivery position, and at least the hand is moved based on the operation command. The operation of the transport drive mechanism is controlled so that the disk-shaped transport object is transported to a predetermined transport target position by moving from the transport start position to a delivery position or a position shifted by the correction operation amount with respect to the delivery position. Preferably there is.

  With such a configuration, the hand is moved from the transfer start position to the transfer position or the transfer position based on an operation command calculated in advance and generated before the hand is moved from the transfer start position toward the transfer position. The disc-shaped transport object can be transported to a predetermined transport target position by moving it to a position shifted by the corrective motion amount all at once, and the corrective motion amount after moving the hand from the transport start position to the delivery position Compared with a configuration that moves only the additional amount, the effects of lost motion and hysteresis of the mechanical system can be avoided or reduced, and the operation tact can be shortened by an amount that does not add extra tact for the minute operation. it can.

  In the transport robot according to the present invention, the center position calculation means of the control unit uses linear sensor position information that is the installation position of each linear sensor on the Cartesian coordinate system. Even if it is installed, it is inevitable that a slight error will occur. Therefore, in the transfer robot of the present invention, the disk-shaped transfer object detected by each linear sensor in the state where the disk-shaped transfer object on the hand is set as a reference and is mounted at the reference position. The reference peripheral position, which is the peripheral position of the sensor, and the mounting position for calibration obtained by displacing the disc-shaped transport object used for extracting the reference peripheral position on the hand by an arbitrary amount different from the reference mounting position A plurality of sets of calibration peripheral positions, each of which is a peripheral position of the disc-shaped conveyance object detected by each linear sensor in the state of being mounted on the substrate, and includes the same number of peripheral positions as the linear sensor. The position coordinates of each linear sensor are estimated using the relative position coordinates of each calibration mounting position with respect to the mounting position, and this estimated linear Can be configured to utilize at the center position calculation means a linear sensor position information based on the capacitors position coordinates. By adopting such a configuration, it is possible to accurately calculate the center position of the disc-shaped conveyance object placed and held on the hand without being affected by the installation error of each linear sensor. Here, there are a plurality of “calibration peripheral positions” used for accurately calculating the center position of the disk-shaped transport target, and the number of calibration peripheral positions in each set is the same as the number of linear sensors. is there. In other words, the number of calibration peripheral positions acquired by the process of extracting one set of calibration peripheral positions is the same as the number of linear sensors. In addition, only one set is sufficient as the “reference peripheral position” used when accurately calculating the center position of the disk-shaped transport object in the above-described manner. Since it is the peripheral position of the disk-shaped conveyance object at the reference placement position detected by the sensor, the number is the same as that of the linear sensor.

  As described above, in the configuration in which the linear sensor position coordinates are estimated using the relative position coordinates of each calibration placement position with respect to the reference placement position, the accurate placement of each calibration placement position with respect to the reference placement position is determined. As a configuration for efficiently acquiring the position coordinates, in the present invention, the disk-shaped transport object is handed after the reference peripheral position extraction process or after the n-th set (n is an integer of 1 or more) calibration peripheral position extraction process. A position where the hand is displaced by an arbitrary amount of displacement with respect to the delivery position by the calibration position correction operation of the first group or m-th group (m is n + 1) to which an arbitrary amount of displacement is added while being placed on the top. The disk-shaped transfer object is moved to the specified transfer destination, the hand returned to the transfer start position is moved to the delivery position without the position correction operation, and the disk-shaped transfer is transferred to the transfer destination. The controller drives the conveyance drive mechanism so as to perform the extraction processing of the peripheral position for calibration of the first group or the m-th group (m is n + 1) with the figurine placed on the hand and returned to the conveyance start position. The relative position coordinates of each calibration placement position with respect to the reference placement position are controlled based on the displacement amount during the calibration position correction operation performed to extract each set of calibration peripheral positions. Can be adopted. If it is the said structure, after the process which extracted the reference | standard peripheral position, the process which extracts the peripheral position for 1st calibration, and the peripheral position for calibration of the nth set (n is an integer greater than or equal to 1, for example, 4) After the process of extracting the m-th calibration (m is n + 1, for example, 5 if n is 4), the calibration peripheral position is extracted through both processes. The amount of displacement during the calibration position correction operation to be performed can be grasped (acquired), and the position of each calibration placement position relative to the reference placement position can be determined based on the amount of displacement during the calibration position correction operation. Accurate relative position coordinates can be acquired.

  In addition, the method for transporting a disc-shaped transport object according to the present invention includes moving a hand from a transport start position to a delivery position along a linear movement path so that the disc-shaped transport object on the hand has a predetermined transport purpose. The present invention relates to a transport method used when transporting a disk-shaped transport object to a transport target position using a transport robot having a transport drive mechanism capable of transport to a position, a peripheral position detection step, a center position calculation step, The operation of the transport drive mechanism is controlled based on the motion command generated in the motion command generation step through the displacement amount calculation step and the motion command generation step.

  Specifically, the peripheral position detection step is a process of detecting three or more different peripheral positions of the disc-shaped transport object placed on the stopped hand at the transport start position by three or more linear sensors. The center position calculating step is a process in which an orthogonal coordinate system is defined by a first axis that is a normal movement path of the hand and a second axis that is orthogonal to the first axis in a horizontal plane including the first axis. Processing for calculating the center position of the disc-shaped transport object on the orthogonal coordinate system based on the linear sensor position information that is the installation position of each linear sensor on the orthogonal coordinate system and the peripheral position detected in the peripheral position detection step It is a process.

  In addition, the displacement amount calculating step includes a reference center position and a center position on an orthogonal coordinate system that is a center position of the disk-shaped transport object when the disk-shaped transport object is placed at a normal placement position on the hand. It is a processing step of calculating a difference (displacement amount) from the center position of the disk-shaped conveyance object calculated in the calculation step, and the operation command generation step is based on the difference (displacement amount) calculated in the displacement amount calculation step. This is a processing step for generating an operation command that defines the operation amount of the transport drive mechanism necessary for transporting the disc-shaped transport target on the hand to a predetermined transport target position. And if it is a disc-shaped conveyance object conveyance method that controls the operation of the conveyance drive mechanism based on the operation command generated in the operation command generation step, it obtains the operation effect according to the operation effect exhibited by the above-described transfer robot. Can do.

  According to the present invention, three or more different positions on the periphery of the disc-shaped conveyance object on the hand stopped by the three or more linear sensors are detected, and the detected peripheral position and the position information of the linear sensor Is used to calculate the center of the disc-shaped transport target placed on the hand, and the difference between the calculated value and the center of the disc-shaped transport target placed on the regular placement position on the hand is calculated. The disk drive object can be moved to a predetermined transfer target position (regular transfer position) with high accuracy by operating the transfer drive mechanism based on the operation command generated based on this difference. It can be transported. In the present invention adopting such a configuration or a transport method, the hand is not affected by the transport speed of the disk-shaped transport object, and the diameter size of the disk-shaped transport object is not used as a known value. Thus, the difference between the position of the disc-shaped transport object placed and held at the regular center position can be accurately obtained, and the disc-shaped transport object can be accurately transported to a predetermined transport target position.

1 is an overall schematic diagram of a transfer robot according to an embodiment of the present invention. FIG. 2 is a diagram corresponding to FIG. 1 of the transfer robot in which the hand is in a delivery position in the embodiment. The principle figure of the peripheral position detection process of the wafer by the linear sensor in the embodiment. The principle figure of the wafer peripheral position detection process of the transparent body by the linear sensor in the embodiment. The figure which shows the relative position of the wafer and linear sensor in the same embodiment on an orthogonal coordinate system. FIG. 3 is a view corresponding to FIG. 2 in a state in which the hand is moved to the delivery position in a state where the wafer is placed at a position not matching the regular placement position on the hand. The functional block diagram of the control part in the embodiment. FIG. 5 is a diagram corresponding to FIG. 5 in a state in which each linear sensor is installed at an arbitrary angle. The figure which shows the position fluctuation amount (position correction amount) of the wafer at the time of the calibration process of the embodiment. The flowchart of the wafer conveyance method which concerns on the same embodiment. FIG. 6 is a view corresponding to FIG. 6 of a transfer robot according to a modification of the present embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The transfer robot T according to the present embodiment moves the hand 23 from the transfer start position (S) shown in FIG. 1 to the delivery position (E) shown in FIG. A transport drive mechanism 1 capable of transporting the upper disc-shaped transport object 7 to a predetermined transport target position, and a control unit 4 that controls the operation of the transport drive mechanism 1 are provided.

  In this embodiment, the wafer 7 is applied as a disk-shaped conveyance object. The wafer 7 is formed with high accuracy in order to eliminate the occurrence of dimensional errors for each individual. Below, the case where the wafer 7 having a diameter of, for example, 300 mm (radius is 150 mm) is transferred to a predetermined transfer target position (regular transfer position) by the transfer robot T will be described.

  As shown in FIGS. 1 and 2, the transfer robot T of the present embodiment is disposed in the wafer transfer chamber A, and the wafer 7 is placed in the processing chamber adjacent to the wafer transfer chamber A or the port B1 in the load lock chamber B. The wafer 7 can be delivered or delivered into a FOUP on a load port (not shown) adjacent to the wafer transfer chamber A. Hereinafter, a case where the wafer 7 is transferred to a predetermined transfer target position (regular transfer position) set in the processing chamber or the load lock chamber B will be described.

  The transport driving mechanism 1 according to the present embodiment has an arm 2 that can move a hand 23 provided at a tip portion along a linear movement path between a transport start position (S) and a delivery position (E). And a main body 3 that rotatably supports the proximal end portion of the arm 2 by the pivot shaft 31. That is, the transport drive mechanism 1 in this embodiment is capable of linear motion and turning motion.

  In this embodiment, as shown in FIG. 1, a plurality of linear sensors (also referred to as line sensors) are provided at positions where the periphery of the wafer 7 placed on the hand 23 at the transfer start position (S) can be detected. ) 6L, 6C, 6R are arranged. Specifically, each of the linear sensors 6L, 6C, 6R is arranged so that three different positions on the periphery of the wafer 7 can be detected by the three linear sensors 6L, 6C, 6R. In this specification, for convenience, the left linear sensor, the central linear sensor, and the right linear sensor in FIGS. 1 and 2 are referred to as “the left linear sensor 6L” and “the central linear sensor 6C”, respectively. And “right linear sensor 6R”.

  The left linear sensor 6L, the center linear sensor 6C, and the right linear sensor 6R are, for example, a light receiving unit 63 (see FIG. 3) in which light receiving elements such as photodiodes that can store an amount of signal charge corresponding to incident light are arranged one-dimensionally. The signal charge according to the amount of light received by the light receiving surface 64 can be transferred to the output unit side by an appropriate charge transfer method using a CCD (charge coupled device) or the like. Note that a linear sensor in which the light receiving unit 63 is configured by a CMOS sensor instead of the CCD sensor may be applied. Alternatively, each of the linear sensors 6L, 6C, and 6R is configured by using a position detection element such as a PSD (Position Sensitive Detector) that itself has a band-shaped light receiving surface and does not require an array of light receiving elements such as a CCD. It is also possible to do.

  Each linear sensor (the left linear sensor 6L, the central linear sensor 6C, and the right linear sensor 6R) of the present embodiment has an amount of incident light obtained by making the irradiation light from the light source 61 into parallel light by the lens 62 as shown in FIG. (An amount proportional to the light intensity level, which is the intensity of light received by the light receiving surface 64 of the light receiving unit 63) is converted into an electric signal, and the reference point 6S (light receiving surface 64 in the linear sensor (center linear sensor 6C in the figure)) is converted. The linear distance Δl (unit: mm) from the sensor edge position (position indicated by reference numeral “6T” in FIG. 3) where the light amount level above a certain value changes to a predetermined value or less to the edge of the wafer 7 It is set to detect as a position. Even when the wafer 7 is formed of a transparent material, as shown in FIG. 4, a linear sensor is utilized by utilizing a change in the light amount level due to the difference in refractive index at the periphery of the wafer 7. (In the figure, the linear distance Δl (unit: mm) from the reference point 6S in the central linear sensor 6C to the sensor pixel position 6T where the light amount level above a certain level changes to a predetermined value or less is detected as the peripheral position of the wafer 7. can do.

  As described above, the transfer robot T according to the present embodiment delivers the hand 23 from the transfer start position (S) in a state where the wafer 7 is mounted at the normal mounting position on the hand 23 (see FIG. 1). It is set so that the wafer 7 on the hand 23 can be accurately transferred to a predetermined transfer target position by moving to the position (E) (FIG. 2). When the movement path from the transfer start position (S) to the delivery position (E) of the hand 23 is defined as a “regular movement path of the hand 23”, each linear sensor (the left linear sensor 6L, the central linear sensor 6C, the right Each linear sensor 6L, 6C, 6R is arranged at a predetermined position in such a posture that the longitudinal direction of the linear sensor 6R) is parallel to the regular movement path of the hand 23. In the present embodiment, only the region on one end edge side in the longitudinal direction of each linear sensor 6L, 6C, 6R overlaps with the wafer 7 placed on the hand 23 at the transfer start position (S) in plan view. The reference point 6S for detecting the peripheral position of the wafer 7 at the center in the width direction of the other edge in the longitudinal direction of each linear sensor (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R). It is set to. In the present embodiment, the reference point 6S includes linear sensor position information (positional coordinates of the linear sensor) that is the installation position of each linear sensor (the left linear sensor 6L, the central linear sensor 6C, and the right linear sensor 6R) described below. It is the same position.

  Here, an axis coinciding with the normal movement path of the hand 23 is defined as a first axis (Y axis), and an axis orthogonal to the first axis in the horizontal plane including the first axis is defined as a second axis (X axis). When the orthogonal coordinate system is defined by one axis and the second axis, the arrangement positions of the linear sensors 6L, 6C, and 6R can be grasped as coordinates on the orthogonal coordinate system. In this embodiment, as shown in FIG. 5, among the linear sensors 6L, 6C, and 6R, the one that is relatively far from the intersection of the Y axis and the X axis (in relation to the disk-shaped transport object 7, The linear sensor receives light at the center position in the width direction (short direction of the linear sensor) at the edge of the edge of the disc-shaped transport object 7 placed on the hand 23 at the transport start position (S) in a plan view. It is assumed that the elements (pixels) are arranged one-dimensionally, and this central position is the arrangement position (coordinates) of each linear sensor 6L, 6C, 6R on the orthogonal coordinate system.

As shown in FIG. 5, the installation position of the left linear sensor 6L on the orthogonal coordinate system is (x _L , y _L ), and the installation position of the central linear sensor 6C on the orthogonal coordinate system is (x _C , y _C ). The installation position of the right linear sensor 6R on the orthogonal coordinate system is (x _R , y _R ). The transfer robot T according to the present embodiment includes installation position information (x _L , y _L ), which are coordinates on the orthogonal coordinate system of these linear sensors (the left linear sensor 6L, the central linear sensor 6C, and the right linear sensor 6R), By using (x _C , y _C ), (x _R , y _R ) and the peripheral position information of the wafer 7 that is a sensing value, the wafer 7 is transferred to a normal transfer position by the transfer robot T as will be described later. It is configured to be able to.

  In some cases, notches such as an orientation flat and a notch are formed on the periphery of the wafer 7. In this case, each linear sensor (the left linear sensor 6L, the center linear sensor 6C, and the right linear sensor 6R) senses a portion of the periphery of the wafer 7 where no notches such as an orientation flat and a notch are formed. The arrangement position of each linear sensor (left linear sensor 6L, center linear sensor 6C, right linear sensor 6R) or the mounting posture (orientation) of the wafer 7 on the hand 23 is set.

  As shown in FIGS. 1 and 2, the arm 2 constituting the transport driving mechanism 1 includes a first link element 21 disposed on the most proximal side (main body 3 side) of the arm 2, and a first link element 21. The second link element 22 is connected to the front end of the second link element 22 so as to be horizontally rotatable, and the hand 23 is an end effector connected to the front end of the second link element 22 so as to be horizontally rotatable. The arm 2 has a link structure (multiple shapes) whose shape changes between a folded state (see FIG. 1) in which the arm length is minimum and an extended state (see FIG. 2) in which the arm length is longer than in the folded state. Joint structure). Further, in the internal space of the first link element 21, a power transmission mechanism (for example, a pulley and a belt) that transmits power to the second link element 22 to rotate the second link element 22 is provided. A power transmission mechanism (for example, a pulley and a belt) that transmits power to the hand 23 to rotate the hand 23 is also provided in the internal space (not shown). Although FIG. 1 shows a hand 23 that is formed in a fork shape having a bifurcated tip, it interferes with sensing processing by each linear sensor (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R). If the condition that does not occur is satisfied, a hand having another shape such as a tip formed in a substantially rectangular shape in plan view may be applied.

  In such an arm 2, the base 23 is horizontally swiveled around the turning shaft 31, or the link elements 21, 22 are horizontally swiveled at the joint portions to appropriately deform the shape of the entire arm 2, and the hand 23 is illustrated. 2 is moved from the transfer start position (S) shown in FIG. 1 (the position of the hand 23 in the arm 2 in the folded state) to the delivery position 23 (E) (the position of the hand 23 of the arm 2 in the extended state) shown in FIG. Thus, the wafer 7 is transferred to a predetermined transfer target position (regular transfer position). Here, as shown in FIG. 1, the Y axis (first axis) overlapping the regular movement path of the hand 23 is a coordinate axis passing through the center 31 a of the turning shaft 31, and the X axis (second axis) orthogonal to the Y axis. Axis) is a coordinate axis orthogonal to the Y axis and passing through the center 31a of the swivel axis 31 in a horizontal plane including the Y axis, and the arm 2 including the hand 23 has an XY coordinate system defined by these coordinate axes (the present invention). It can be considered as moving on the plane of (orthogonal coordinate system).

The motion coordinate system of the turning shaft 31 and the arm 2 can be shown as a robot motion polar coordinate system (r, θ). “R” is the traveling direction (r-axis direction) of the hand 23 passing through the center 31 a of the turning shaft 31, and “θ” is the rotation angle of the r-axis around the turning shaft 31. Then, the center position of the wafer 7 at the time when the wafer 7 is transferred to the regular transfer position (in this embodiment, a predetermined transfer target position set in the processing chamber or the load lock chamber B) by the transfer drive mechanism 1 ( r ₀ , θ ₀ ), the Y axis coincides with the r axis direction when θ is θ ₀ (see FIG. 2).

  As shown in FIG. 6, when the hand 23 is moved from the transfer start position (S) to the delivery position (E) in a state where the wafer 7 is placed at a position shifted from the normal placement position on the hand 23. Then, the center position 7a of the wafer 7 on the hand 23 after the movement is shifted from the center position 7a of the wafer 7 when the wafer 7 is transferred to a predetermined transfer target position (regular transfer position). Displaces according to the amount. In FIG. 6, the wafer 7 placed and held at a position displaced from the normal placement position in the hand 23 is indicated by a solid line, and the wafer 7 placed and held at a regular placement position in the hand 23 is indicated by a broken line.

  As a specific arrangement of the linear sensors (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R) arranged in parallel to the Y axis on the XY coordinate system, for example, the left linear sensor 6L is arranged in the second quadrant ( The X linear coordinate 6R is arranged in the first quadrant (a point where both the X coordinate and the Y coordinate take a positive value) and is arranged in an area where the X coordinate takes a negative value and the Y coordinate takes a positive value. In this embodiment, the central linear sensor 6C is arranged in the first quadrant. However, in the present embodiment, the central linear sensor 6C is arranged in the first quadrant. Therefore, an arrangement different from the standard arrangement is adopted.

  In the transfer robot T according to the present embodiment, the control unit 4 that controls the operation of the transfer drive mechanism 1 includes a peripheral position detection unit 41, a center position calculation unit 42, and a displacement amount calculation unit 43, as shown in FIG. And an operation command generation means 44 and a position correction execution means 45. 1 and 2 exemplify a mode in which the control unit 4 is built in or attached to the main body unit 3, the control unit 4 is connected to the main body unit 3 by connecting an information processing device or the like separate from the control unit 4. 4 can also be configured.

The peripheral position detection means 41 detects each peripheral position of the wafer 7 by each linear sensor (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R). Specifically, as shown in FIG. 5, the peripheral position detection means 41 has the reference point 6S of the light receiving surface 64 in each linear sensor 6L, 6C, 6R (the conveyance start position (in each linear sensor 6L, 6C, 6R) A sensor in which the light quantity level received by the light receiving surface 64 is switched to a predetermined value or less from the edge in the width direction of the edge that does not overlap the outer peripheral edge of the wafer 7 placed on the stopped hand 23 in S). A linear distance (see FIGS. 3 and 4) to the pixel position 6T is detected (extracted) as the peripheral position of the wafer 7. In the present embodiment, the position (reference point 6S) of one edge of the light receiving surface 64 in each linear sensor 6L, 6C, 6R is the coordinates (x _L , y) of each linear sensor 6L, 6C, 6R on the XY coordinate system. _L ), (x _C , y _C ), (x _R , y _R ), and the sensor pixel position 6T at which the light amount level is switched below the predetermined value on the light receiving surface 64 of each linear sensor 6L, 6C, 6R, that is, in plan view The position where each linear sensor 6L, 6C, 6R intersects the periphery of the wafer 7 is defined as coordinates (x _L , y _Li ), (x _C , y _Ci ), (x _R , y _Ri ) on the XY coordinate system. The peripheral position of the wafer 7 detected by each linear sensor 6L, 6C, 6R is detected (extracted) as Δy _Li , Δy _Ci , Δy _Ri (unit: mm) on the XY coordinate system.

The center position calculation means 42 includes linear sensor position information that is the installation position of each linear sensor 6L, 6C, 6R on the XY coordinate system, and the peripheral position Δy _Li , Δy _Ci , of the wafer 7 detected by the peripheral position detection means 41. The center position of the wafer 7 is calculated using Δy _Ri . In this embodiment, the reference point 6S of the light receiving surface 64 of each linear sensor 6L, 6C, 6R is used as the linear sensor position information of each linear sensor 6L, 6C, 6R. However, the installation error of the linear sensors 6L, 6C, 6R is used. In order to eliminate this, position coordinates estimated based on data acquired by a calibration process described later can be used as linear sensor position information of each of the linear sensors 6L, 6C, 6R.

Here, the linear sensor position information is the coordinates (x _L , y _L ), (x _C , y _C ), (x _R , y _R ) of the reference point 6S of each linear sensor 6L, 6C, 6R shown in FIG. , The coordinates (x _L , y _L ), (x _C , y _C ), (x _R , y _R ), and the periphery of the wafer 7 acquired by the sensing process of each linear sensor 6L, 6C, 6R Coordinates (x _L , y _Li ), (x _C , y _Ci ), positions where the linear sensors 6L, 6C, 6R and the peripheral position of the wafer 7 intersect in a plan view by the positions Δy _Li , Δy _Ci , Δy _Ri , (X _R , y _Ri ) is a coordinate represented by Equation 1 below.

The center coordinates of the wafer 7 placed on the hand 23 in the stopped state at the transfer start position (S) are (x _i , y _i ), and the wafer 7 is a circle having a radius R _i (unit: mm). Assuming that, the equation shown by the following formula 2 holds from the three-square theorem.

When the above equation is solved with respect to (x _i , y _i ), which is the center coordinate of the wafer 7, the following equation 3 is obtained.

In the center position calculation means 42 according to the present embodiment, the center position 7a of the wafer 7 placed on the hand 23 in the stopped state at the transfer start position (S) is coordinated on the XY coordinate system by the arithmetic processing shown in Formula 3. It is configured to calculate as (x _i , y _i ). In addition, the said Numerical formula 3 is an example of the numerical solution which solved the equation shown by the said Numerical formula 2, and may become the type | formula further rearranged or deform | transformed depending on the derivation method of the solution.

In the present embodiment, as shown in FIG. 5, the linear sensor 6L, 6C, 6R is at the transport start position (S) according to the above mathematical formula 3 on the assumption that the longitudinal direction is parallel to the Y axis. The center position 7a of the wafer 7 placed on the hand 23 in the stopped state is calculated as coordinates (x _i , y _i ) on the XY coordinate system. However, as shown in FIG. 8, it can be assumed that the longitudinal direction of each linear sensor 6L, 6C, 6R is not parallel to the Y axis but is installed at an arbitrary angle. In this case, the coordinates of the position where each of the linear sensors 6L, 6C, 6R and the peripheral position of the wafer 7 intersect in plan view can be grasped as Equation 4 below.

Here, if θ _L , θ _C , and θ _R in FIG. 8 are positive in the counterclockwise direction in FIG. 8, Δx _L1 , Δy _L1 , Δx _C1 , Δy _C1 , Δx _R1 , and Δy _R1 in Equation 4 are 5 can be represented.

Assuming that the wafer 7 is a circle having a radius R _i (unit: mm), the equation of the circle shown in Equation 6 below is established.

Solving the equation (6) with respect to the center coordinates (x _i , y _i ) of the wafer 7 gives the following equation (7). The coordinates (x _L , y _L , θ _L ), (x _C , y _C , θ _C ), (x _R , y _R , θ _R ) of the installation positions of the linear sensors 6L, 6C, 6R are set to known values. Then, the coordinates (x _i , y _i ) of the center position 7a of the wafer 7 can be obtained from the peripheral positions Δl _L1 , Δl _C1 , Δl _R1 detected by the linear sensors 6L, 6C, 6R.

The displacement amount calculation means 43 is calculated by the reference center position on the XY coordinate system, which is the center position of the wafer 7 when the wafer 7 is placed at the normal placement position on the hand 23, and the center position calculation means 42. The difference (displacement amount) from the center position of the wafer 7 is calculated. Specifically, in the displacement amount calculating means 43, the reference center position on the XY coordinate system is set to (x ₀ , y ₀ ), and the center position (x _i ) of the wafer 7 with respect to the reference center position (x ₀ , y ₀ ). , Y _i ), the displacement amount (Δx, Δy) is calculated by the equation (8).

  The operation command generation unit 44 is based on the difference (displacement amount) calculated by the displacement amount calculation unit 43 and is required to transfer the wafer 7 on the hand 23 to a predetermined transfer destination position. The operation command which prescribes | regulates is produced | generated. The transfer robot T according to the present embodiment employs a transfer drive mechanism 1 that includes a turning shaft 31 and an arm 2. As described above, the operation coordinate system of the turning shaft 31 and the arm 2 is a robot operation polar coordinate system. It can be shown as (r, θ). Then, the wafer 7 at the time when the hand 23 is moved from the transfer start position (S) to the delivery position (E) along the normal transfer path in a state where the wafer 7 is mounted on the normal load position on the hand 23. The displacement amount (Δx, Δy) calculated by the displacement amount calculation means 43 can be expressed by the following Equation 9 when the Y coordinate of the center position of “n” is “r”.

  Since the normal transfer position (predetermined transfer target position) is a positive value on the Y axis in the XY coordinates, the operation command generation unit 44 in this embodiment uses the first quadrant and the second in the coordinates. The correction amount (Δr, Δθ) of the transport drive mechanism 1 on the robot motion polar coordinate system (r, θ) is calculated as shown in the following Equation 10 only for position correction within the two quadrants (condition: r + Δr> 0). Seeking by processing.

  Note that the computing capacity of the device for calculating the correction amount (Δr, Δθ) of the transport drive mechanism 1 is not sufficient, and the “r” is added to Δy among the displacement amounts (Δx, Δy) calculated by the displacement amount calculation means 43. When the added distance (r + Δy) is sufficiently larger than Δx of the displacement amount (Δx, Δy) calculated by the displacement amount calculating means 43, the arithmetic processing shown in the following formula 11 obtained by the first approximation of Taylor expansion Thus, the correction amount (Δr, Δθ) of the transport drive mechanism 1 on the robot operation polar coordinate system (r, θ) may be calculated.

  The position correction execution unit 45 controls the operation of the turning shaft 31 and the arm 2 based on the operation command of the transport drive mechanism 1 calculated by the operation command generation unit 44, so that the wafer 7 placed on the hand 23 is moved. Position correction processing for moving to a predetermined transfer target position (regular transfer position) is executed.

  Next, using such a transfer robot T and each linear sensor (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R), the center position 7a of the wafer 7 placed on the hand 23 and the reference About a method and an action of detecting a difference from the center position and actually reflecting the detected value on the operation of the turning shaft 31 and the arm 2 to transfer the wafer 7 to a predetermined transfer target position (regular transfer position). explain.

  In this embodiment, when detecting the difference between the center position 7a of the wafer 7 placed on the hand 23 and the reference center position, each linear sensor (left linear sensor 6L, center linear sensor 6C, right linear sensor 6R) is detected. ) And the position information on the coordinates of the linear sensors 6L, 6C, 6R themselves are used. However, the linear sensors 6L, 6C, and 6R are accurately arranged at design positions due to various influences such as assembly accuracy of a device that supports the linear sensors 6L, 6C, and 6R at predetermined positions and processing accuracy of parts. This is difficult, and some errors occur between the actual positions of the linear sensors 6L, 6C, and 6R and the designed positions. When the transfer process of the wafer 7 is executed without considering this error, it is assumed that the accuracy of transferring the wafer 7 to the regular transfer position is lowered.

  Therefore, in the present embodiment, calibration processing is performed in advance for each linear sensor (the left linear sensor 6L, the center linear sensor 6C, and the right linear sensor 6R), and data (a plurality of calibration data) acquired by the calibration processing is used. The position coordinates of each of the linear sensors 6L, 6C, 6R are estimated by use.

  The calibration process is based on one mounting position of the wafer 7 on the hand 23, and each linear sensor (the left linear sensor 6L, the central linear sensor 6C, the right) in a state where the wafer 7 is mounted on the reference mounting position. Calibration is performed by displacing the reference peripheral position, which is the peripheral position of the wafer 7 detected by the linear sensor 6R), and the wafer 7 used for extracting the reference peripheral position from the reference mounting position (an arbitrary amount different from each other). A plurality of sets of calibration peripheries, each of which is a peripheral position of the wafer 7 detected by each of the linear sensors 6L, 6C, 6R in the state of being mounted at the mounting position for the calibration, and includes the same number of peripheral positions as the linear sensors. Each linear sensor using the position and the relative position coordinate of each calibration placement position with respect to the reference placement position. L, 6C, is a process for estimating the position coordinates of the 6R.

  Here, a procedure for acquiring a reference peripheral position and a plurality of sets of calibration peripheral positions used in the process of estimating the position coordinates of each linear sensor 6L, 6C, 6R will be described.

  First, the center position 7a of the wafer 7 on the port B1 in the load lock B chamber, which is the transfer destination of the wafer 7, is approximately the center position of the wafer 7 transferred to the regular transfer position (predetermined transfer target position). Place it in a matching position in advance.

  In the transfer robot T of the present embodiment, the transfer drive mechanism 1 is operated without position correction by the operation control by the control unit 4 in accordance with dedicated teaching data used at the time of calibration, and the wafer 7 placed on the port B1. Is transferred onto the hand 23 positioned at the delivery position (E), and the hand 23 is moved to the transport start position (S). When the wafer 7 is transferred between the hand 23 and the port B1, the entire transport driving mechanism 1 may be moved up and down by an appropriate lifting mechanism (not shown), or the transport driving mechanism 1 may be moved. It may be configured so that it cannot be moved up and down, and the port B1 may be moved up and down by a lifting mechanism provided in the processing chamber or the load lock chamber B.

In the transfer robot T of this embodiment, the wafer 7 is taken out from the processing chamber or the load lock chamber B, the hand 23 is stopped at the transfer start position (S), and each linear sensor (the left linear sensor 6L, the central linear sensor) is stopped. The peripheral positions (Δl _L1 *, Δl _C1 *, Δl _R1 *) of the wafer 7 on the hand 23 are detected by the sensor 6C and the right linear sensor 6R, respectively, and these circumferential positions (Δl _L1 *, Δl _C1 *, Δl) are detected. _R1 *) and the center position of the wafer 7 at the time of detection is the above-mentioned reference center position (when the wafer 7 is mounted at the normal mounting position on the hand 23 at the transport start position (S) in the stopped state). A set of a displacement (amount of deviation) (Δx ₁ *, Δy ₁ *) with respect to the center position 7a of the wafer 7 (reference center position on the orthogonal coordinate system) is the first carry. The data is stored in a predetermined storage unit as vibration data. Here, the amount of deviation (Δx ₁ *, Δy ₁ *) at the time of obtaining the first calibration data is (0, 0). Here, the placement position of the wafer 7 on the hand 23 at the time of the first calibration data acquisition is the “reference placement position” at the time of the calibration process, and the periphery of the wafer 7 placed at this reference placement position. The position (Δl _L1 *, Δl _C1 *, Δl _R1 *) becomes the “reference peripheral position”. The reference peripheral position extraction process is completed by the above procedure.

Subsequent to the extraction process of the reference peripheral position, the transfer robot T of the present embodiment detects the peripheral position (Δl _Ln *) of the wafer 7 detected by each linear sensor (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R). , Δl _Cn *, Δl _Rn *), and a process of acquiring a plurality of sets of calibration peripheral positions with one set of the same number of peripheral positions as the linear sensor (extraction processing of calibration peripheral positions). In the present embodiment, the peripheral position (Δl _Ln *, Δl _Cn *, Δl _Rn *) of each set of wafers 7 and a shift amount (Δx _n *, Δy _n *) = (Δx _n , Δy _n ), which will be described later, A process of acquiring a plurality of sets of data (calibration data) that are combined. In addition, “n” in the coordinate value means what number of calibration data. In the present embodiment, 49 sets of calibration data are set to be acquired.

A procedure for extracting a plurality of sets of calibration peripheral positions (in other words, a procedure for acquiring the second and subsequent calibration data) will be described below. Subsequently to the acquisition of the first calibration data, the control unit 4 adjusts the position correction amount (Δx for calibration) to the XY coordinate position (x _hand , y _hand ) of the hand 23 shown in FIG. 9 based on the teaching data. _{n 2} , Δy _n ), the arm 2 and the turning shaft 31 are actuated to move the hand 23 from the transfer start position (S) toward the delivery position (E), and the wafer 7 is transferred to the processing chamber. Alternatively, after transporting to the load lock chamber B and transferring to the port B1, the hand 23 is moved to the transport start position (S). As a result, the center position 7a of the wafer 7 on the port B1 is a position correction amount for calibration (Δx _n , Δy _n ) with respect to the center position of the wafer 7 transferred to the regular transfer position on the port B1. It is displaced by the minute. That is, the above-mentioned “deviation amount” means the position correction amount for this calibration. Note that “n” in the calibration position correction amount (Δx _n , Δy _n ) means the position correction amount at the time of calibration data acquisition. The position correction amounts (Δx _n , Δy _n ) of the hand 23 at the time of the calibration process are set so as to be different from each other in the numerical order of the order of spiral displacement from the center one shown in FIG. Note that the position correction amount for calibration is not an equal interval, and may be an arbitrary value in the transport area where the position correction operation is performed in actual transport. Further, the acquisition order of calibration data is not limited to a spiral shape, and may be an appropriate order.

Subsequently, in the transfer robot T of the present embodiment, the peripheral position of the wafer 7 on the hand 23 in the stopped state at the transfer start position (S) is detected by each linear sensor 6L, 6C, 6R, and this detection value (Δl _L2 *, Δl _C2 *, Δl _R2 *) and a deviation amount (Δx ₂ *, Δy ₂ *) = (Δx ₂ , Δy ₂ ) of the center position of the wafer 7 with respect to the reference center position described above at the time of detection Is stored in a predetermined storage unit as second calibration data. In the present embodiment, the procedure according to the procedure for acquiring the second calibration data is repeated until the 49th calibration data is acquired. Here, the placement position and the peripheral position of the wafer 7 in the second and subsequent calibration data are the “calibration placement position” and the “calibration peripheral position” in the present invention. As described above, the number of calibration peripheral positions in each group is the same as the number of linear sensors (when the position of the linear sensor is estimated by an optimization problem as will be described later, The number is the same as the number of parameters to be estimated, that is, the number of linear sensors, and is “3” in this embodiment. The number of calibration data to be acquired is not limited to “49”, and can be set to an appropriate number.

  Based on the plurality of calibration data acquired by the above procedure, the position coordinates of the linear sensors 6L, 6C, 6R are estimated.

Specifically, at each placement position (reference placement position and calibration placement position) where the center position (x _i , y _i ) of the wafer 7 is placed on the hand 23 different from each other. In this embodiment in which data of the peripheral position (reference peripheral position and calibration peripheral position) of the wafer 7 is acquired by calibration processing, each linear sensor to be estimated (the left linear sensor 6L, the central linear sensor 6C, the right linear) The position coordinates of the sensor 6R) are set to the coordinates shown in the following formula 12, and the peripheral position of the wafer 7 and the radius of the wafer 7 detected by the linear sensors 6L, 6C, 6R before the execution of the calibration process are expressed by the following formula. 13 and paying attention to the fact that the error ε of the linear sensor can be expressed by the following equation 14: Each coordinate shown in Equation 12 that minimizes the evaluation function J shown in Equation 15 is obtained by an optimization method, and each of these coordinates is obtained as the position of each linear sensor (the left linear sensor 6L, the central linear sensor 6C, and the right linear sensor 6R). It can be a coordinate. Here, in order to make an optimization problem that minimizes the evaluation function J, ε ² is used in which the error ε, which takes a positive or negative value, is squared to be a positive value.

  Since the process of acquiring calibration data is performed using the same wafer 7, the radius of the wafer 7 is a value that does not depend on the number of measurements. Here, Formula 15 can be expressed as an evaluation function shown in Formula 16 below based on Formula 14.

Then, the deviation amount of the center position coordinates (x _i , y _i ) of the wafer 7 at each placement position (calibration placement position) with respect to the reference center position (x ₀ , y ₀ ) of the wafer 7 on the hand 23 is calculated. (Δx _i *, Δy _i *) and the peripheral position of the wafer 7 detected by each linear sensor (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R) is Δl _Li *, Δl _Ci *, Δl _Ri *. ,, The evaluation function J can be organized into the following equation (17).

  Then, by substituting a plurality of sets of calibration data acquired by the calibration process into the equation 17, the coordinates shown in the equation 12 are obtained by an optimization method, and the obtained coordinates are obtained from each linear sensor (the left linear sensor 6L). , The position coordinates of the center linear sensor 6C and the right linear sensor 6R).

  For the optimization problem in which the evaluation function J is an extreme value (minimized in this case), a steepest descent method, a quasi-Newton method, a conjugate gradient method, or the like, which is a general nonlinear optimization solution, can be used.

  As the amount of deviation of the wafer 7 increases, the calculation accuracy of the center position of the wafer 7 using the estimated position coordinates of each linear sensor (left linear sensor 6L, center linear sensor 6C, right linear sensor 6R) tends to deteriorate. If there is, an evaluation function J ′ multiplied by a weight W proportional to the amount of deviation is used to estimate the position coordinates of each linear sensor (left linear sensor 6L, central linear sensor 6C, right linear sensor 6R). Processing may be performed. An example of weighting is shown in Equation 18 below.

  Further, when it takes time to estimate the position coordinates of each linear sensor 6L, 6C, 6R, or the calculation result is a local solution, the calculation accuracy of the estimated value for the true value (the coordinate value of the actual installation position of the linear sensor) is high. In order to avoid a decrease, the optimization problem may be solved by giving the attachment position ranges of the linear sensors 6L, 6C, and 6R as constraint conditions in advance.

  Furthermore, when each linear sensor 6L, 6C, 6R is installed in parallel with a predetermined coordinate axis (Y-axis), the value related to θ is 0. Therefore, each linear sensor 6L, The position coordinates of 6C and 6R can be estimated.

  The transfer robot T of the present embodiment estimates the position coordinates of each linear sensor (left linear sensor 6L, center linear sensor 6C, right linear sensor 6R) through such arithmetic processing, and then detects the peripheral position detection shown in FIG. Each process after step S1 is performed.

That is, after carrying out the linear sensor position coordinate estimation process, the transfer robot T according to the present embodiment first performs a predetermined receiving destination (for example, a FOUP placed on a load port (not shown)) by the operation control of the control unit 4. The wafer 7 to be transferred received on the hand 23 from the inside is placed and held, and the peripheral position of the wafer 7 on the hand 23 in a stationary state at the transfer start position (S) is detected by the peripheral position detection means 41 ( Peripheral position detection step S1, see FIG. Specifically, in the peripheral position detection step, as shown in FIG. 5, the reference point 6S (x _L , y _L ) of the light receiving surface 64 in each linear sensor (left linear sensor 6L, center linear sensor 6C, right linear sensor 6R). ), (X _C , y _C ), (x _R , y _R ), the sensor pixel position 6T (x _L , y _Li ), (x _C , y _Ci ) at which the light level received by the light receiving surface 64 is switched to a predetermined value or less. ), (X _R , y _Ri ) are detected (extracted) as peripheral positions Δy _Li , Δy _Ci , Δy _Ri (unit: mm) of the wafer 7. In the present embodiment, the reference points 6S (x _L , y _L ), (x _C , y _C ), (x of the light receiving surface 64 in each linear sensor (left linear sensor 6L, center linear sensor 6C, right linear sensor 6R). _{As R 1} , y _R ), the position coordinates of each linear sensor (the left linear sensor 6L, the center linear sensor 6C, and the right linear sensor 6R) estimated through the calibration process described above can be used.

Subsequently, the transfer robot T according to the present embodiment uses the center position calculation unit 42 of the control unit 4 to detect the linear sensor position information and the peripheral position (Δy _Li , Δy _Ci , A center position calculation step S2 for calculating the center position 7a of the wafer 7 is performed using Δy _Ri ) (see FIG. 10). In this embodiment, the position coordinates of the linear sensors 6L, 6C, and 6R estimated through the calibration process can be used as the linear sensor position information. The linear sensor position information and the detection of the linear sensors 6L, 6C, and 6R can be used. Using the peripheral position (Δy _Li , Δy _Ci , Δy _Ri ) of the wafer 7 that is a value, the wafer is placed on the hand 23 in the stopped state at the transfer start position (S) by the arithmetic processing shown in the mathematical formula 3. The center position 7a of the wafer 7 is calculated as coordinates (x _i , y _i ) on the XY coordinate system.

Next, the transfer robot T according to the present embodiment uses the displacement amount calculation unit 43 of the control unit 4 to determine the reference center position of the wafer 7 (this wafer when the wafer 7 is placed at a regular placement position on the hand 23). 7) and the difference (displacement amount) between the center position 7a (x _i , y _i ) of the wafer 7 calculated in the center position calculation step S2 (displacement amount calculation step S3, see FIG. 10). In this displacement amount calculation step S3, the reference center position on the XY coordinate system is set to (x ₀ , y ₀ ), and the center position (x _i , y _i ) of the wafer 7 with respect to this reference center position (x ₀ , y ₀ ). The displacement amount (Δx, Δy) is calculated according to the equation (8).

Subsequently, the transfer robot T of this embodiment is necessary for transferring the wafer 7 on the hand 23 to a predetermined transfer target position based on the displacement amounts (Δx, Δy) calculated in the displacement amount calculation step S3. An operation command that defines the operation amount of the transport drive mechanism 1 is generated by the operation command generation means 44 of the control unit 4 (operation command generation step S4, see FIG. 10). In this operation command generation step S4, the hand 23 is moved from the transfer start position (S) to the delivery position (E) along the normal transfer path in a state where the wafer 7 is mounted at the normal position on the hand 23. The Y coordinate of the center position of the wafer 7 at the time of this is set to “r”, and the robot operation polar coordinate system (limited to the position correction in the first quadrant and the second quadrant (condition: r + Δr> 0) on the coordinates ( The correction amount (Δr, Δθ) of the transport driving mechanism 1 on (r, θ) is obtained by the arithmetic processing shown in the equation 10. When the displacement amount of the center position (x _i , y _i ) of the wafer 7 with respect to the reference center position (x ₀ , y ₀ ) on the XY coordinate system is _zero in the displacement amount calculation step S3, that is, the reference center position. When (x ₀ , y ₀ ) and the center position (x _i , y _i ) of the wafer 7 coincide with each other, in the operation command generation step S5, the regular movement amount of the transport drive mechanism 1 (movement amount in the case of no position correction). ) Is generated with an amount of correction for zero.

The transfer robot T according to the present embodiment is placed on the hand 23 by controlling the operation of the turning shaft 31 and the arm 2 based on the operation command of the transfer drive mechanism 1 calculated in the operation command calculation step S4. A position correction process for transferring the wafer 7 being transferred to a predetermined transfer target position (regular transfer position) is executed (see position correction execution step S5, FIG. 10). In the present embodiment, an operation command for the transport driving mechanism 1 is generated before the hand 23 is moved from the transport start position (S) toward the delivery position (E), and the turning shaft 31 is generated based on the operation command. And the hand 23 is turned from the transfer start position (S) to the delivery position (E) or delivery position (E) including the amount reduced by the correction amount (Δr). On the other hand, the wafer 7 is moved from the wafer transfer chamber A to the processing chamber or load that is the transfer destination by moving to the position shifted by the correction amount (Δr, Δθ) without stopping for a predetermined time or longer. In the lock chamber B, position correction processing is performed for transporting to a predetermined transport target position (regular transfer position) set in advance. Here, when the reference center position (x ₀ , y ₀ ) and the center position (x _i , y _i ) of the wafer 7 actually placed and held on the hand 23 match, the transport drive mechanism 1 The hand 23 moves from the transport start position (S) to the delivery position (E) along the normal movement path. On the other hand, if the reference center position (x ₀ , y ₀ ) and the center position (x _i , y _i ) of the wafer 7 actually placed and held on the hand 23 do not match, the transport drive mechanism 1 is Position correction operation is performed based on an operation command including a correction amount in the movement amount of the hand 23, and the hand 23 subtracts correction amounts (Δr, Δθ) from the transfer start position (S) to the delivery position (E). Move to a position that is offset by the same amount. In any case, the wafer 7 placed and held on the hand 23 can be transported to a predetermined transport target position (regular transfer position).

  The transfer robot T of the present embodiment transfers the wafer 7 to a predetermined transfer target position in the processing chamber or the load lock chamber B, and then operates the above-described lifting mechanism (lifting means) to move the wafer 7 on the hand 23. The wafer 23 is transferred to the port B1 in the processing chamber or the load lock chamber B, and the hand 23 on which the wafer 7 is not placed and held is moved to the transfer start position (S).

  With the above procedure, the wafer 7 placed and held on the hand 23 can be transferred to the regular transfer position. Then, when there is a wafer 7 to be transferred next, that is, when the next transferred wafer 7 is placed on the hand 23, the above steps S1 to S5 are repeated, and each wafer 7 is transferred to the regular transfer. It can be transported to the loading position.

As described above, the transfer robot T according to the present embodiment uses the three linear sensors (the left linear sensor 6L, the left linear sensor 6L, the peripheral portion of the wafer 7 placed on the hand 23 in the stopped state at the transfer start position (S). If the central linear sensor 6C and the right linear sensor 6R are respectively detected, and a plurality of peripheral positions (each linear sensor 6L, 6C, 6R) that are detected values thereof are installed in parallel to the Y axis, each linear sensor 6L , 6C, 6R are Δy _Li , Δy _Ci , Δy _Ri shown in FIG. 5. If the linear sensors 6L, 6C, 6R are not installed in parallel to the Y axis, each linear sensor A plurality of peripheral positions detected by 6L, 6C, and 6R are Δl _L1 , Δl _C1 , and Δl _R1 shown in FIG. 8) and the positions where the linear sensors 6L, 6C, and 6R are installed. Based on the near sensor position information (x _L , y _L ), (x _C , y _C ), (x _R , y _R ), it is placed on the hand 23 stationary at the transfer start position (S). The center position (x _i , y _i ) of the wafer 7 on the orthogonal coordinate system is calculated. As a result, in the middle of moving the hand 23 on which the wafer 7 is placed and held while accelerating from the transfer start position (S) toward the delivery position (E), the point where the wafer 7 starts to pass through the sensor is passed. If the configuration is such that the center point of the wafer 7 is calculated based on the straight line distance between the detected points, that is, the finished point, a problem that can occur, that is, an increase in the wafer conveyance speed due to variations in scan timing. As a result, the sensing accuracy deteriorates, and the sensing accuracy at the end of passing, where the transfer speed is relatively high, is inferior to the sensing accuracy at the start of passage, where the transfer speed is relatively slow. An error occurs in the value, and the center position of the wafer calculated based on the detected value including the error also deviates from the true value, and is calculated based on the center position. It can be precision by correcting the deviation amount with respect to the mounting position of the normal to be conveyed a predetermined conveying target position to avoid the problem of deterioration.

  Furthermore, since the transfer robot T according to the present embodiment does not use the diameter size of the wafer 7 placed on the hand 23 as a known value when calculating the center position 7a of the wafer 7, for example, Even in the case of wafers 7 having different diameter sizes for each individual due to high temperature processing or the like, the center position of each wafer 7 can be calculated with high accuracy.

  Further, in the transfer robot T according to the present embodiment, detection is performed by sensing each of three different peripheral positions on the wafer 7 in a stationary state with the respective linear sensors (the left linear sensor 6L, the central linear sensor 6C, and the right linear sensor 6R). Since the center position of the wafer 7 is calculated based on the value, the influence of the elastic deformation of the transmission mechanism (pulley or belt) interposed between the driving source for driving the transport driving mechanism 1 and the hand 23 is provided. This also contributes to improving the accuracy of calculating the center position of the wafer 7.

  The transfer robot T according to the present embodiment actually calculates the center position 7a of the wafer 7 actually placed on the hand 23 on the hand 23 by accurately calculating the center position 7a with respect to the true value without error. An accurate difference between the center position 7a of the wafer 7 placed on the wafer 7 and the reference center position, which is the center position when the wafer 7 is placed at the regular placement position on the hand 23, can be obtained. Including this difference, an operation command that defines the amount of movement of the transport drive mechanism 1 necessary for transporting the wafer 7 on the hand 23 to a predetermined transport target position (the normal placement position of the wafer 7 on the hand 23). When the device is placed at a position deviated from the position, an operation command including a correction operation amount is generated, and the conveyance drive mechanism 1 is operated based on the operation command. Have Correct the deviation amount between the center position and the reference center position of the wafer 7, it is possible to transport the wafers 7 are placed on the hand 23 to a predetermined transport destination position.

  In addition, the transfer robot T according to the present embodiment generates an operation command for the transfer drive mechanism 1 before moving the hand 23 from the transfer start position (S) toward the delivery position (E). Based on the command, the swivel shaft 31 and the hand 23 are operated at once according to the operation amount including the correction amount without temporarily stopping in the middle of each, and from the transfer start position (S) to the delivery position (E) or the delivery position. Since the wafer 7 is transferred to a predetermined transfer target position by moving it to a position shifted by a correction operation amount with respect to (E), the hand 23 is moved from the transfer start position (S) to the delivery position. Compared with the configuration in which the turning shaft 31 is turned by the amount of motion correction after the movement to (E) or the hand 23 is moved, the influence of lost motion and hysteresis of the mechanical system is avoided or reduced. It is possible, tact small operation amount is not Kakekara extra, it is possible to shorten the operation cycle time.

  In addition, the transfer robot T according to the present embodiment uses the calibration acquired by the calibration process as the linear sensor position information (position coordinates of each of the linear sensors 6L, 6C, 6R) used by the center position calculating unit 42 of the control unit 4. Since the values estimated based on the operation data are applied, the installation of the linear sensors 6L, 6C, 6R on the hand 23 eliminates slight installation errors that cannot be avoided even if they are mounted with a high degree of accuracy. Thus, the center position of the wafer 7 can be accurately calculated.

  In particular, in the present embodiment, as a procedure for acquiring calibration data and estimating the position coordinates of each of the linear sensors 6L, 6C, 6R, one mounting position of the wafer 7 on the hand 23 is used as a reference, and the reference mounting is performed. A set of reference peripheral positions, which are peripheral positions of the wafer 7 detected by the respective linear sensors 6L, 6C, 6R in the state of being placed at the mounting position, and the wafer 7 used for extracting the reference peripheral position, The peripheral position of the wafer 7 detected by each of the linear sensors 6L, 6C, 6R in a state where it is placed on the calibration placement position displaced from the reference placement position by an arbitrary amount different from each other, and Multiple sets of calibration peripheral positions with one set of the same number of peripheral positions as the linear sensor, and each calibration with respect to the reference placement position Utilizing the calibration data consists of the relative position coordinates of mounting positions, and estimates a linear sensor position coordinates. Therefore, even when the position of each linear sensor is not accurately adjusted at the time of sensor installation (not accurately adjusted), the position of each linear sensor can be defined by the above method. It becomes possible to accurately calculate the center position of the wafer using the position of each defined linear sensor.

  Further, in the transfer robot T according to the present embodiment, the wafer 7 is placed on the hand 23 after the extraction process of the reference peripheral position or after the extraction process of the n-th set (n is an integer of 1 or more) the calibration peripheral position. The hand 23 is moved to a position shifted by an arbitrary displacement amount from the delivery position (E) in the first or m-th (m is n + 1) calibration position correction operation with an arbitrary displacement amount. Then, the wafer 7 on the hand 23 is transferred to a predetermined transfer destination (port B1 in the processing chamber or the load lock chamber B in the present embodiment), and the hand 23 returned to the transfer start position (S) is subjected to position correction. The wafer 7 moved to the delivery position 23 (E) without operation and transferred to the transfer destination during the extraction process of the reference peripheral position or the extraction peripheral position of the n-th set (n is an integer of 1 or more). The The controller 4 transports the first set or the m th set (m is n + 1) of the peripheral edge positions for calibration while being placed on the card 23 and returned to the transfer start position (S). Displacement during calibration position correction operation for controlling the operation of the drive mechanism 1 and extracting the relative position coordinates of each calibration placement position with respect to the reference placement position for each set of calibration peripheral positions. Since the configuration of acquiring based on the quantity is adopted, it is possible to efficiently acquire the accurate relative position coordinates of each calibration mounting position with respect to the reference mounting position used when estimating the linear sensor position coordinates. it can.

  In addition, this invention is not limited to embodiment mentioned above. For example, the disk-shaped conveyance object may be other than a wafer, such as a liquid crystal.

  In addition, the disk actually placed on the hand based on the operation command (command generated by the motion command generation means (motion command generation step)) after operating the transport drive mechanism by the normal amount of motion. A position correction operation according to the amount of deviation between the center position of the object to be conveyed and the reference center position may be additionally performed. In this case, the timing for generating the operation command of the transport driving mechanism is that the hand is moved from the transport start position toward the delivery position before the hand is moved from the transport start position in the stopped state toward the delivery position. It may be any time during or after the hand is moved from the transfer start position to the delivery position.

  Moreover, the number of linear sensors should just be three or more, and the number of the peripheral positions of the disk-shaped conveyance target detected by a linear sensor becomes the same as the number of linear sensors.

  Further, the installation position (position coordinates) of each linear sensor used in the center position calculation means (center position calculation step) may be a design installation position (position coordinates) instead of a value estimated by the calibration process. Absent.

  Further, the installation position (position coordinates) of each linear sensor that can be estimated or acquired by an appropriate process or method other than the calibration process can be used in the center position calculation means (center position calculation step).

  When estimating the installation position (positional coordinates) of each linear sensor by calibration processing, the marker position on the disk-shaped transport object is measured by an image processing device such as an area sensor, or used as a drive source for the transport drive mechanism. Based on the information of an attached position detector such as an encoder, the displacement (relative position coordinates) of each calibration placement position with respect to the reference placement position may be calculated directly or indirectly.

  Moreover, the conveyance drive mechanism should just be what can convey the disk-shaped conveyance thing mounted and hold | maintained on the hand along a linear movement path | route, and the number and shape of the link elements which comprise an arm, a joint part (axis | shaft). ) Can be changed as appropriate. Furthermore, the link elements may be connected so as to be slidable instead of or in addition to the horizontal turning operation.

  Furthermore, as shown in FIG. 11, the transport drive mechanism has an axis center 31a of the turning shaft 31 of the arm 2 that is not on the first axis (Y axis), but in the second axial direction ( It may be at a position displaced by an arbitrary value in the X-axis positive direction or the X-axis negative direction). FIG. 11 is a view showing the transport drive mechanism according to this modified example corresponding to FIG. 6, and parts corresponding to the parts shown in FIG. 6, dimension display, angle display, etc. are denoted by the same reference numerals. ing. In FIG. 11, the linear sensor is omitted. The arm 2 shown in FIG. 11 is set to a position in which the axis center 31a of the turning shaft 31 is displaced by an arbitrary value in the negative direction of the second axis with respect to the first axis, as compared with the arm 2 shown in FIG. The third link element 24 having a longitudinal dimension corresponding to the amount of displacement in the X-axis direction relative to the Y-axis of the pivot axis 31a is interposed between the second link element 22 of the arm 2 and the hand 23. In addition, the distal end portion of the second link element 22 and the proximal end portion of the third link element 24 are connected so as to be capable of relative swiveling, and the distal end portion of the third link element 24 and the proximal end portion of the hand 23 can be relatively swiveled. It is different in that it is connected to. The tip shape of the hand 23 and the number and dimensions of the link elements interposed between the second link element and the hand can be appropriately changed.

  The transport drive mechanism may be a multi-arm type having a plurality of arms. As an example, a two-arm robot in which arms as shown in FIG. 11 are arranged symmetrically about the first axis (Y axis) can be mentioned. Of course, a multi-arm robot in which the pivot axes of the arms are set at the same position may be used.

  In addition, as the transport driving mechanism, a Cartesian coordinate system robot that can move the hand straightly along two axes orthogonal to each other (the first axis and the second axis in the present invention) can be applied.

  Further, the longitudinal directions of three or more linear sensors may be arranged in parallel or substantially parallel to a direction (X-axis direction) orthogonal to the normal movement path of the hand.

  In addition, as a mode of holding the disk-shaped transport object in a state of being placed on the hand, “vacuum suction holding” for holding by vacuum suction, so-called “Bernoulli holding” using the Bernoulli effect, mechanical nails, “Mechanical holding” that holds the disk-shaped transport object in physical contact with a roller, “Static holding” that holds the disk-shaped transport object with electrostatic force, and holds by the gravity of the disk-shaped transport object itself. (For example, the hand is provided with a groove or three or more notches, and the disc-shaped conveyance object is held in the groove or the plurality of notches) “gravity holding”, any of these mounting and holding modes may be used. .

  Further, the transfer destination of the disk-shaped transfer object is not limited to the port in the processing chamber or the load lock chamber, but may be in the FOUP on the load port or an appropriate port.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Conveyance drive mechanism 23 ... Hand 4 ... Control part 41 ... Perimeter position detection means 42 ... Center position calculation means 43 ... Correction amount calculation means 44 ... Operation command generation means 45 ... Position correction execution means 6L, 6C, 6R ... Linear sensor (Left linear sensor, center linear sensor, right linear sensor)
7 ... Disc-shaped transfer object (wafer)
T ... Transport robot

Claims (5)

A transport drive mechanism capable of transporting the disk-shaped transport object on the hand to a predetermined transport target position by moving the hand from a transport start position to a delivery position along a linear movement path; and the transport drive mechanism A control unit for controlling the operation of
The control unit is
A peripheral position detection means for detecting three or more different peripheral positions of the disc-shaped transport object placed on the hand in a stopped state at the transport start position by three or more linear sensors;
The installation position of each linear sensor on an orthogonal coordinate system defined by a first axis along the normal movement path of the hand and a second axis orthogonal to the first axis in a horizontal plane including the first axis. Center position calculating means for calculating a center position of the disc-shaped transport object on the orthogonal coordinate system based on certain linear sensor position information and the peripheral position detected by the peripheral position detecting means;
Calculated by the center position calculation means and the reference center position on the Cartesian coordinate system, which is the center position of the disk-shaped transport object when the disk-shaped transport object is placed at a regular placement position on the hand Displacement amount calculating means for calculating a difference from the center position of the disc-shaped transport object,
Based on the difference calculated by the displacement amount calculation means, an operation command is generated that defines an operation amount of the transport drive mechanism necessary for transporting the disc-shaped transport object on the hand to the predetermined transport target position. Operation command generating means for
A transport robot characterized in that the operation of the transport drive mechanism is controlled based on the motion command generated by the motion command generation means. The control unit generates the operation command at a time before moving the hand from the transfer start position toward the delivery position, and based on the operation command, at least the hand is moved from the transfer position to the transfer position or 2. The operation of the transport drive mechanism is controlled so that the disk-shaped transport object is transported to a predetermined transport target position by moving to a position shifted by the correction operation amount with respect to the delivery position. The transfer robot described in 1. The peripheral position of the disc-shaped transport object detected by the linear sensor in a state where the disc-shaped transport object is placed on the hand with the reference position as a reference. A reference peripheral position;
The disk-shaped transport object used for extracting the reference peripheral position is detected by the linear sensor in a state where it is placed on a calibration placement position displaced from the reference placement position on the hand. A plurality of sets of calibration peripheral positions which are the peripheral positions of the disc-shaped conveyance object and have the same number of the peripheral positions as the linear sensor.
Using the relative position coordinates of the calibration mounting positions with respect to the reference mounting position, the position coordinates of the linear sensors are estimated,
The transport robot according to claim 1, wherein the center position calculation unit uses the linear sensor position information based on the estimated position coordinates of the linear sensors. Arbitrary displacement with the disc-shaped transport object placed on the hand after the extraction processing of the reference peripheral position or after the extraction processing of the calibration peripheral position of the n-th set (n is an integer of 1 or more) The disc-shaped conveyance is performed by moving the hand to a position shifted by an arbitrary displacement amount with respect to the delivery position by the calibration position correcting operation of the first group or m-th group (m is n + 1) to which the amount is added. The object is transferred to a predetermined transfer destination, the hand returned to the transfer start position is moved to the delivery position without a position correction operation, and the disk-shaped transfer object transferred to the transfer destination is moved to the transfer destination. The controller drives the transport so that the calibration peripheral position of the first group or the m-th group (m is n + 1) is extracted while being returned to the transport start position while being placed on the hand. Control the operation of the mechanism Relative position coordinates of each calibration placement position with respect to the reference placement position are acquired based on a displacement amount during a calibration position correction operation performed to extract each set of calibration peripheral positions. The transfer robot according to claim 3. Utilizing a transport robot having a transport drive mechanism capable of transporting the disc-shaped transport object on the hand to a predetermined transport target position by moving the hand from a transport start position to a delivery position along a linear movement path And a transport method for transporting the disc-shaped transport object,
A peripheral position detection step of detecting three or more different peripheral positions of the disc-shaped transport object placed on the hand in a stopped state at the transport start position by three or more linear sensors;
An installation position of each linear sensor on an orthogonal coordinate system defined by a first axis that is a normal movement path of the hand and a second axis that is orthogonal to the first axis in a horizontal plane that includes the first axis. A center position calculating step for calculating a center position of the disc-shaped transport object on the orthogonal coordinate system based on linear sensor position information and the periphery position detected in the periphery position detection step;
Calculated by the center position calculation step and the reference center position on the Cartesian coordinate system, which is the center position of the disk-shaped transport object when the disk-shaped transport object is placed at a regular placement position on the hand. A displacement amount calculating step for calculating a difference from the center position of the disc-shaped transport object,
Based on the difference calculated in the displacement amount calculating step, an operation command that defines an operation amount of the transport driving mechanism necessary for transporting the disc-shaped transport object on the hand to the predetermined transport target position is generated. Through the operation command generation step to
A method for transporting a disk-shaped transport object, wherein the operation of the transport drive mechanism is controlled based on the motion command generated in the motion command generation step.

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