KR102225139B1 - Method for restoring positional information of robot - Google Patents

Abstract

Re-teaching is not required when the robot is replaced, either when the robot is replaced, or when the robot is reassembled or relocated, and it is possible to easily resolve problems in the data and verify the validity of the location information. Provides a way.
Before and after the robot exchange, the origin offset of the robot and a predetermined position coordinate indicating the position and posture of the robot in the external coordinate system when the robot's hand is extended and moved to a predetermined position are acquired. The difference in the origin offset before and after the robot exchange is referred to as the first deviation amount, and the deviation amount based on the difference in the predetermined position coordinates is referred to as the second deviation amount. It is managed as.

Description

How to restore robot's location information {METHOD FOR RESTORING POSITIONAL INFORMATION OF ROBOT}

The present invention relates to a method for restoring positional information so that the previous teaching data can be used by the robot when replacing equipment in a robot, reassembling or relocating a robot, or the like.

In a robot that operates based on teaching (teaching) data, there are cases in which equipment such as a motor or arm constituting the robot is replaced, and the robot itself is reassembled or relocated, if necessary. When the device is replaced, reassembled, and relocated, the amount of error related to the assembly or installation of the robot changes. Therefore, it is necessary to re-teach the robot before performing work by the robot again. However, since teaching a robot requires a lot of time and labor, it is desired to be able to use the previous teaching data even in the case of exchanging devices, reassembling or relocating the robot, and the like. Patent Document 1 relates to a robot that performs processing on a work held by a holding device, before and after the transfer of the robot, the positions of the three positions of the holding device or the work held by the holding device are determined by the robot. It is disclosed that the teaching data is corrected so that a change in the relative position between the robot and the holding device is compensated based on a change in the measurement result before and after the robot is moved, and measured by a visual sensor installed on the arm.

In robots, the position of each axis (especially the rotational position) is obtained by a sensor (for example, an encoder), but when the motor, reducer, or arm is replaced, the reference position used to determine the position of each axis is shifted. This is also the cause of the inability to use the previous teaching data after the replacement of the device, but Patent Document 2 discloses that pin holes are provided in each of a pair of structures (for example, arms, etc.) constituting the joint axis of the robot. A method of defining a reference position by inserting a pin penetrating through the hole, or by providing a V-shaped groove in one structure constituting the joint axis and a proximity sensor corresponding to the V-shaped groove in the other structure, Disclosed is a method of specifying a reference position by a signal.

When equipment is replaced, the robot itself is reassembled or relocated, and furthermore, in order to cope with changes over time, the robot is calibrated. In the case of calibration, the instrument parameters used to describe the robot kinematically change, and the teaching data used before calibration cannot be used as it is. Patent Document 3 discloses that the teaching data is corrected and used based on the instrument parameter before calibration and the instrument parameter after calibration.

By the way, among various robots, a horizontal articulated robot is used for conveyance of semiconductor wafers, glass substrates, etc., for example. Patent documents 4 and 5 disclose examples of a horizontal articulated robot for transport using a semiconductor wafer or a glass substrate as a transport object. With the increase in the size of the object to be conveyed by the horizontal articulated robot and the complexity of the process performed on the object to be conveyed, the horizontal articulated robot itself has also increased in size, and the transport distance of the object to be conveyed is also increasing. When the horizontal articulated robot becomes large, it is also necessary to disassemble and transport the robot once and reassemble it at the place after completing and adjusting the robot in order to ship the robot and mount it to the customer.

Japanese Patent No. 3733364 Japanese Patent No. 4819957 Japanese Patent Publication No. 2017-213668 Japanese Patent Publication No. 2015-139854 Japanese Patent No. 5199117

Patent Document 1-3 discloses a method of allowing the use of previous teaching data without re-teaching even when the robot is replaced with equipment, reassembled or relocated to the robot itself, or even recalibrated the robot. I'm doing it. The methods of Patent Documents 1-3 are all one set of correction data (if Patent Document 1, data relating to the displacement of the position related to the specific holding device before and after relocation, Patent Document 2, data for correcting the reference position, Patent Document If it is 3, it is based on the data on the deviation of the instrument parameter before and after calibration). However, when the robot becomes large and its movement range is also increased, such as a horizontal articulated robot for transport, the method of Patent Document 1-3 cannot sufficiently correct the teaching data, and as a result, inevitably. In some cases, re-classification may occur. In addition, when there is a problem with the correction data used to correct the teaching data, it is difficult to cope with the cause of the problem, and it is difficult to verify the validity of the correction data. .

It is an object of the present invention in robots such as large horizontal articulated robots for transport, which eliminates the need for re-teaching when replacing equipment constituting the robot, reassembling or relocating the robot, and eliminating data problems. It is to provide a method for restoring location information that can easily verify validity.

The positional information restoration method of the present invention is a method for restoring positional information of a robot used in a processing apparatus having a plurality of processing chambers and supporting an object and conveying it between a plurality of processing chambers based on teaching data. It has a base to be installed, a hand that supports the object, and at least one arm interposed between the base and the hand, and replaces a part of the robot, reassembles part or all of the robot, or transfers the robot. As a result, before executing the robot exchange, a step of storing the robot's origin offset and a predetermined position coordinate indicating the robot position and posture when the hand is stretched and moved to a predetermined position, and after the robot exchange, the robot's origin offset is acquired. Then, the step of storing the first amount of shift, which is the difference between the origin offset before the robot exchange and the origin offset after the robot exchange, and after the robot exchange, extend the hand to move the robot to a predetermined position to obtain the predetermined position coordinates, and obtain the predetermined position before the robot exchange. A second shift amount is calculated and stored based on the difference between the position coordinates and the predetermined position coordinates after the robot is exchanged, and the first shift amount and the second shift amount are separately managed.

In the present invention, since the correction amount used for correction of the teaching data is divided into two of the first deviation amount based on the origin offset and the second deviation amount based on the predetermined position coordinates, and these deviation amounts are separately managed, When there is an abnormality, it is possible to easily determine that there is an abnormality and the amount of deviation in which the abnormality exists. In addition, even if data loss or the like occurs in the process of calculating the amount of deviation, if the first amount of deviation is calculated, the first amount of deviation can be used as it is and the second amount of deviation can be calculated, thereby reducing the time required for calculating the amount of correction. can do.

In the position information restoration method of the present invention, a single reference marker is provided in the processing device, and at least a part of the object mounted on the hand and the reference marker are imaged by a visual sensor to obtain the position of the object, thereby making the object separate from the robot. It is preferable to acquire predetermined positional coordinates in a coordinate system, for example, a coordinate system of a processing device. The deviation that occurs in the predetermined position coordinates when the robot is moved to a predetermined position after exchanging is mainly caused by a positional deviation in the plane on which the robot is installed (a deviation in XY coordinates with the installation plane of the robot as the XY plane) and of the robot. This is caused by a misalignment (angular misalignment), but in a large robot, the influence of the misalignment of the orientation is greater than that of the position. The use of is sufficient, and the calculation for calculating the second deviation amount can be made concise.

In the present invention, after the robot is exchanged, the robot is moved to the origin position by rough adjustment by an origin sensor provided in the robot and fine adjustment by a fitting means that regulates the mutual positions of structures included in the robot, You can get the origin offset. By moving the robot to the origin position in this order when acquiring the origin offset, it is possible to accurately align the position to the origin position by a mechanical means in the robot. Thereby, even when only one reference marker is used, when teaching data is corrected based on the first shift amount and the second shift amount, the robot can accurately move to a desired position based on the teaching data.

In the present invention, the processing apparatus is provided with two reference markers, and at least a part of the object mounted on the hand and the reference marker are imaged with a visual sensor to obtain the position of the object, thereby obtaining a coordinate system separate from the robot, for example, It is also possible to obtain the predetermined positional coordinates in the coordinate system of the processing device. In the case of providing two reference markers, since the positional deviation and the angle deviation included in the second deviation amount can be separated, even if there is a slight error in the origin offset, the first deviation amount and the second deviation amount Based on the corrected teaching data, it is possible to accurately move the robot to a desired position. In the case of providing two reference markers, the shape of the object is made into a square shape, and when the robot is in a predetermined position, it is recommended to provide two reference markers corresponding to each of the ends of one diagonal line of the object. desirable. By providing the reference markers corresponding to both ends of the diagonal line, the distance between the reference markers increases, and it is possible to detect a shift in orientation in the robot with high accuracy.

In the present invention, it is preferable to provide a reference marker in any one of the plurality of processing chambers. In the processing apparatus, by using the reference marker provided in the processing chamber that is actually used, it is possible to correct the teaching data for the deviation in the processing chamber that is actually used. When the reference marker is provided in the processing chamber in this way, it is preferable that the predetermined position is the position at which the hand is farthest from the base in the processing chamber. Since the robot's arm and hand are unfolded and the position farthest from the base in the processing chamber is set to a predetermined position, the deviation of the robot's orientation can be detected as a large value, making it possible to correct the teaching data with high precision. .

In the present invention, it is preferable to move the robot to a predetermined position based on teaching data actually used in the robot. By moving based on the teaching data actually used, the shift amount is calculated in consideration of the moving direction of the robot, and the influence of the backlash can be reduced. At this time, until the deviation of the predetermined position coordinates before and after the robot exchange is within the allowable range, correct the teaching data using the first deviation amount and the second deviation amount, and set the robot from the origin position based on the corrected teaching data. It is possible to repeat moving to the position and recalculating the second shift amount. By such repetitive calculations, the accuracy of correcting the teaching data can be improved.

Advantageous Effects of Invention According to the present invention, there is no need for re-teaching at the time of exchange of devices constituting a robot, reassembly or relocation of the robot, and it is possible to easily solve problems in data and verify validity.

1 is a diagram showing an example of a robot, (a) is a plan view, (b) is a front view, and (c) is a front view of the robot at the origin position.
2 is a block diagram showing a circuit configuration of a robot and a robot controller.
FIG. 3A is a diagram showing a processing apparatus in which the robot shown in FIG. 1 is provided, and FIG. 3B is a diagram schematically showing a cross section of a processing chamber.
4 is a flowchart showing an operation of a method for restoring location information according to the present invention.
5 is a diagram schematically showing a processing chamber of another example.

Next, preferred embodiments of the present invention will be described with reference to the drawings. Before describing the method for restoring location information based on the present invention, first, an example of a robot to which the method for restoring location information is applied will be described.

1 shows an example of a robot to which the method for restoring position information based on the present invention is applied. 1A and 1B are plan and front views showing a robot in a state in which an arm or hand is extended. The robot shown in FIG. 1 is the same as the horizontal articulated robot for transport described in Patent Document 4, and includes the base 11, the first arm 12 provided on the base 11, and the first arm 12. A second arm 13 provided at the tip end and a hand 14 provided at the tip end of the second arm 13 are provided. The hand 14 holds a semiconductor wafer, a glass substrate, or the like as an object to be conveyed, and is formed in a fork shape. With respect to the base 11, the first arm 12 is rotatable around the axis A, with respect to the first arm 12, the second arm 13 is rotatable around the axis B, and the second arm ( For 13) the hand 14 is rotatable around the axis C. In order to enable rotation around the axes A to C, which are joint axes of the robot, the robot is equipped with a motor for each axis. Further, the robot is provided on the base 11 and a mechanism for lifting the first arm 12 in the illustrated Z direction is provided, and this lifting mechanism is also driven by a lifting motor. All of the axes A to C are parallel to the Z direction. Each of the base 11, arms 12 and 13, and the hand 14 is a structure included in the robot.

In the robot shown in Fig. 1, an origin position, which is a reference for the operation of the robot, is determined, and at the origin position, the arm or hand is in a predetermined folded position. 1C shows the posture of the robot at the origin position, and so that the second arm 13 and the hand 14 overlap on the first arm 12, the second arm 13 and the hand ( 14) is folded.

A robot controller is provided to control the robot shown in Fig. 1. 2 shows the electrical circuit configuration of the robot and the robot controller 40. As described above, the robot is provided with four motors 15 in total for the axes A to C and the lifting mechanism. These motors 15 include encoders 16 that measure the rotation angle of the motor 15, respectively. Installed.

The robot controller 40 includes a bus 41 used to transmit various signals and data, a servo circuit 42 provided for each motor 15 to drive the motor 15, and the operation and control of the robot. A CPU (central processing unit) 43 that performs necessary calculations and outputs commands to each servo circuit 42, and a storage unit 44 that stores data necessary for calculation or control by the CPU 43 is provided. . The storage unit 44 includes a teaching data storage unit 51 that stores teaching data as a storage area or file, an origin offset storage unit 52 that stores an origin offset, and a predetermined position coordinate that stores a predetermined position coordinate. The storage unit 53 is set. The origin offset and the predetermined position coordinates will be described later. The servo circuit 42, the CPU 43 and the storage unit 44 are connected to the bus 41. The output from the encoder 16 is supplied to the servo circuit 41 that drives the corresponding motor 15 and is also sent to the CPU 43 via the bus 41. The robot controller 40 is connected to a camera 23 as a visual sensor and a teaching pendant 60 used for teaching the robot, and they are connected to the bus 41 through an interface circuit (not shown).

Next, a usage mode of the robot described here will be described with reference to FIG. 3. Here, it is assumed that a robot is used in a processing apparatus used to manufacture a liquid crystal display or an organic EL (electroluminescence) display by performing a process such as film formation or etching on the work 31, which is a substantially rectangular glass substrate. do. As shown in FIG. 3A, the processing apparatus includes a conveyance chamber (transfer chamber) 21 and a plurality of processing chambers (process chambers) 22 arranged so as to surround the conveyance chamber 21. In the processing chamber 22, there are provided for carrying in or out of the work 31 into the manufacturing system itself, and there are provided for performing film formation, etching, or other processing on the work 31. The robot is provided in the conveyance chamber 11 by installing the base 11 in the conveyance chamber 21, and carries out the conveyance of the work 31 passing through the conveyance chamber 21 between the processing chambers 22. Therefore, the robot is provided approximately in the center of the conveyance chamber 21, and when the work 31 is transferred, the arms 12 and 13 are extended so that the hand 14 enters the processing chamber 22.

Among the plurality of processing chambers 22, for example, on the ceiling surface of the processing chamber 22 used for carrying in/out of the work 31 to the outside of the manufacturing system, as shown in FIG. 3(b), a reference marker ( 24) is provided, and a camera 23 is provided on the bottom surface of the processing chamber 22 so as to photograph the reference marker 24. The camera 23 is also drawn in Fig. 3A. The camera 23 and the reference marker 24 are used to determine whether or not the work 31 mounted on the hand 14 of the robot is mounted at the correct position on the hand 14. Based on the teaching data, the robot is moved with respect to the processing chamber 22 equipped with the camera 23 and the reference marker 24, and the edge (corner) of the work 31 is taken by the camera 23 at that time. By photographing the marker 24, it is possible to know whether the work 31 is correctly mounted on the hand 14 or in which direction and how much the work 31 is shifted from the original position. When the loading position of the workpiece 31 is shifted from the original position, the loading position of the workpiece 31 can be corrected by a position correction device (not shown).

Next, a method of restoring location information in an embodiment of the present invention will be described. The method of restoring position information of the present embodiment is a case in which equipment such as a motor or arm constituting a robot is replaced, or when there is a reassembly or relocation of the robot itself, and before their replacement, reassembly, or relocation, the robot can be used. The used teaching data can be used even after exchange, reassembly, or relocation without re-teaching. Hereinafter, the replacement of the device in the robot and the reassembly or relocation of the robot itself will be collectively referred to as robot replacement.

As described above, the origin position serves as a reference for the position and posture when moving the robot, and in the robot at the origin position, the rotation positions of the respective motors 15 of the robot are all considered to be zero. The rotational position of the motor 15 is measured by the encoder 16 connected to the motor 15 and output to the robot controller 40. However, depending on the assembly and mounting state of the motor 15 to the arms 12 and 13 or the hand 14, and the assembly and mounting state between the motor 15 and the encoder 16, even if the robot is in the home position, the encoder 16 The value of the rotational position output from) does not just become zero. The rotational position measured by the encoder 16 when the robot is at the origin position is referred to as an origin offset. When moving the robot based on the teaching data, in the teaching data, the rotation position at the origin position is set to zero, and then compensation by the origin offset is performed, or the rotation position at the origin position is assumed to be a value indicated by the origin offset. Teaching data needs to be described. In any case, when the robot is replaced, for example, when the motor 15 and the hands 12 and 13 are replaced, the value of the origin offset is generally different before and after the replacement. Therefore, in order to use the same teaching data before and after the robot exchange without re-teaching, it is necessary to correct the teaching data based on the change in the origin offset caused by the robot exchange.

In the case of obtaining the origin offset after replacing the robot, it is necessary to move the robot to the origin position. At this time, since the origin offset after replacement of the robot is not yet known, the robot cannot be moved to the origin position by an origin return command or the like to the robot. So, you can move the robot to the origin position using the teaching pendant while looking at the robot with your eyes. In order to more accurately move the robot to the home position, for example, as described in Patent Document 2, pin holes for regulating the robot's posture to the posture at the home position are provided on the arms 12 and 13 or the hand 14. The robot can be fixed at the original position by providing a jig pin and inserting a jig pin into the pin hole. In the case of using a jig pin, separate from the encoder 16, an origin sensor is provided on one of two structures (arms 12, 13 or hand 14) that share a joint axis, and the origin sensor is detected on the other. The robot is mechanically originated by preparing grooves or protrusions that can be made, making rough adjustments based on the output of the origin sensor, and then slowly moving the robot to the position where the jig pin is inserted into the pin hole. You can move it to a location. The jig pin and the pin hole function as fitting means for regulating the mutual positions of the structures (here, the base 11, arms 12 and 13, and the hand 14) included in the robot.

By the way, the origin position is a state in which the arms 12 and 13 or the hand 14 of the robot are folded, and in the case of a robot with a long arm or hand such as a transport robot, just by compensating for the change in the origin offset, the arm 12 , 13) and the hand 14 are not only able to be accurately moved to a desired position in the case of extending and moving the hand 14. This is because the installation position and orientation of the robot may be shifted due to replacement of the robot. Therefore, in the present embodiment, on the basis of the teaching data, the arms 12 and 13 and the hand 14 of the robot are extended and moved to a predetermined position before and after the robot exchange. And in an external coordinate system separate from the robot's own coordinate system (for example, a coordinate system defined in the processing chamber 22), coordinates representing the position and posture of the robot are obtained. This coordinate is called a predetermined position coordinate. Since the predetermined position coordinates are for compensating for misalignment that cannot be compensated by the origin offset measured in the folded state of the arms 12 and 13 or the hand 14, the arms 12 and 13 or the hand 14 It is desirable to measure at a position as extended as possible and as spaced apart as possible from the base 11 of the robot. Therefore, in the present embodiment, predetermined position coordinates are measured using the camera 23 and the reference marker 24 provided in the processing chamber 22. It is preferable that the camera 23 and the reference marker 24 are provided in the processing chamber 22 on the side far from the conveyance chamber 21.

In the measurement of the predetermined position coordinates, the measuring jig is placed as the workpiece 31 at the correct position of the hand 14, and the hand 14 is transferred to the processing chamber 22 based on the teaching data while the measuring jig is mounted. It is moved and photographed by the camera 24 so that the measuring jig is taken. In the present embodiment, as a jig for measurement, for example, a square shape is used, and the edge of the jig is extracted from the image photographed by the camera 24, and the image of the reference marker 24 and the image of the edge of the jig The coordinates of the edge of the jig are obtained from the positional relationship of, and this is taken as the coordinates of the predetermined position of the robot. At this time, the coordinates of the positions of the vertices of the rectangular measuring jig may be obtained, or the orientations of the two sides connected to the vertices may be obtained as representing the attitude of the robot in addition to the coordinates of the vertices. Since the reference marker 24 is fixed in the processing chamber 22, the coordinates of the edge of the jig obtained here, that is, the predetermined positional coordinates, represent the position of the robot in the external coordinate system. The reason for moving the robot based on the teaching data in the measurement of the predetermined position coordinates is to eliminate the influence of the backlash.

In the positional information restoration method of the present embodiment, the amount of change in the origin offset before and after the robot exchange is referred to as the first amount of deviation, and the amount of change in the predetermined position coordinates before and after the robot exchange is referred to as the second amount of deviation. The method described in Patent Documents 1 and 3 is, in the end, a method of measuring what corresponds to the sum of the first deviation amount and the second deviation amount and using it for correction of teaching data, and the method described in Patent Document 2 is the first deviation. It is about the measurement of quantity. In contrast, in this embodiment, when the teaching data is reused after the robot is exchanged, the teaching data is corrected using both the first deviation amount and the second deviation amount, but the first deviation amount and the second deviation amount are separated. It is managed as. In the storage unit 44, the origin offset before and after robot replacement and the first shift amount calculated therefrom are stored in the origin offset storage section 52, and the predetermined position coordinates before and after the robot replacement and the second shift amount calculated therefrom are It is stored in the predetermined position coordinate storage unit 53.

In the present embodiment, the first and second misalignment amounts are managed separately, when both are managed as one, even if there is an abnormality in these misalignment amounts, it becomes difficult to detect the anomaly, and any misalignment. This is because it is sometimes difficult to determine whether an abnormality has occurred in the quantity. There is a possibility that the difference in the length of the arm before and after the replacement may affect the second displacement amount, but the influence of the difference in the installation position and orientation of the robot is larger than the conceivable difference in the length of the arm. It is okay to think that the second amount of deviation is the amount of deviation with respect to the position of the robot with respect to the external coordinate system. In contrast, the first amount of deviation is the amount of deviation with respect to the coordinates of the robot itself. Therefore, there is no problem in separately managing these misalignments. In addition, even if data loss occurs due to, for example, a voltage abnormality in the process of acquiring the first and second misalignment amounts, if the calculation of the first misalignment amount has been completed, it is necessary to perform it again from the beginning. Is not, and the first shift amount already calculated can be used as it is, and the calculation of the second shift amount can be performed.

Here, the second amount of misalignment is reviewed. The second shift amount includes a component generated by a shift in the installation position of the robot in the plane on which the robot is installed, and a shift in the orientation of the robot. The goal of this embodiment is to reuse the teaching data without re-teaching after the robot is exchanged, and when the teaching data is reused, the error of the position of the hand 14 in each processing room 22 is within a predetermined value. will be. For example, a deviation of 1 mm in the installation position of the robot is only a deviation of 1 mm in the position of the hand 14, but the lengths of the arms 12, 13 and the hand 14 of the robot are summed. Considering this large-sized transport robot of 3 m, a deviation of 0.1° in the orientation of the robot corresponds to a deviation of about 5 mm at the position of the extended hand 14. It is easy to set the error of the installation position (difference of the center position of the robot) to 1 mm or less, but it is difficult to make the error of orientation to 0.1° or less. Therefore, it can be considered that the second shift amount is to correct the shift in the orientation of the robot after the robot is exchanged, and if so, it is possible to obtain the second shift amount by a simple calculation using one reference marker 24. Then, the teaching data can be reused by correcting the teaching data used before the robot exchange by using the accurately determined first deviation amount and the second deviation amount calculated using one reference marker 24.

In the present embodiment, the second shift amount is determined using the camera 23 and the reference marker 24 provided in a certain processing chamber 22, but the processing chamber 22 in which the camera 23 and the reference marker 24 are provided. ) Is preferably a processing chamber 22 that is actually used when moving the robot based on the teaching data. In addition, if the second amount of deviation is obtained from the predetermined position coordinates, the teaching data is corrected using the first amount of deviation and the second amount of deviation, and after returning to the original position, it is moved to the above-described predetermined position to obtain the predetermined position coordinates. , When the difference between the previously determined position coordinates and the current determined position coordinates is within the allowable value, the amount of deviation is determined, and otherwise, the second amount of deviation is repeatedly updated according to the previously determined position coordinates, whereby the teaching data is reused. Can increase the accuracy of correction.

4 shows an example of processing by the position information restoration method of the present embodiment. First, in step 101, the origin offset before performing the robot exchange is stored in the origin offset storage unit 52. When a robot is installed, since it would normally be done by aligning the origin of the robot to obtain the origin offset, the value may be used. Next, in step 102, a measuring jig is installed on the robot as the workpiece 31, the robot is moved to the predetermined position described above based on the teaching data, and the jig is made using the camera 23 and the reference marker 24. Detects the edge of and obtains the predetermined position coordinates. The predetermined position coordinates obtained here are referred to as position P, and are stored in the predetermined position coordinate storage unit 53. This is the preparatory step before the robot replacement is performed. Subsequently, in step 103, the robot is replaced, that is, equipment such as a motor or arm in the robot is replaced, and the robot itself is reassembled or relocated.

After the end of the robot exchange, in step 104, the robot is mechanically moved to the origin position as described above, the origin offset after the robot exchange is obtained, and stored in the origin offset storage unit 52, and in step 105, the origin offset is stored. The difference in the origin offset stored in the unit 52 before and after the robot exchange is determined as the first shift amount, and stored in the origin offset storage unit 52. Subsequently, in step 106, the same measurement jig as used in step 102 is mounted on the robot, and the robot is moved to a predetermined position using the teaching data corrected based on the first shift amount, and a predetermined value is carried out in the same manner as described above. The position coordinates are obtained, and the predetermined position coordinates at this time are set as the position Q and stored in the predetermined position coordinate storage unit 53. In step 107, the second shift amount is calculated from the difference between the position P and the position Q, and stored in the predetermined position coordinate storage unit 53.

Next, in step 108, the robot is moved to the origin position by inputting a command to the robot controller 40, and thereafter, the robot is operated using the corrected teaching data based on the first and second shift amounts. It moves from the origin position to a predetermined position, obtains the predetermined position coordinates in the same manner as described above, and stores the predetermined position coordinates at this time in the predetermined position coordinate storage unit 53 as the position R. Then, in step 109, it is determined whether or not the difference between the position P obtained before replacing the robot and the position R obtained this time exceeds an allowable value. When it exceeds the allowable value, since the second deviation amount has not been obtained with high precision, in step 110, the second deviation amount is recalculated based on the difference between the position P and the position R, and a predetermined position coordinate storage unit I remember it in (53). In the recalculation of the second shift amount, since a shift exceeding the allowable value has occurred in the position P and the position R in the second shift amount before the recalculation, an operation to obtain a value that corrects the second shift amount to eliminate this shift. Do. After the execution of step 110, the process returns to step 108, and the processing of steps 108 to 110 is repeated until the difference between the position P and the position R is within the allowable value. In step 109, if the difference between the position P and the position R is within the allowable value, it is assumed that the second shift amount is determined, and the process is terminated.

As described above, after the first shift amount and the second shift amount are determined and stored in the origin offset storage unit 52 and the predetermined position coordinate storage unit 53, respectively, the teaching data used before the robot exchange is determined. By performing the correction based on the 1st shift amount and the 2nd shift amount, it becomes possible to continue to use the teaching data even after the robot is exchanged.

According to the embodiment described above, by separately calculating, storing, and managing the first shift amount based on the origin offset and the second shift amount based on the predetermined position coordinates, it is possible to reliably detect an abnormal value in the shift amount. In addition, by correcting the teaching data using the first deviation amount and the second deviation amount, the teaching data used before the robot exchange can be used even after the robot exchange without re-teaching. In addition, although the robot controller 40 shown in Fig. 2 is capable of separately managing the origin offset and the predetermined position coordinates, the hardware configuration is not different from a general robot controller, so the position information restoration method of the present embodiment is , Can be realized using a general robot controller.

In the position information restoration method of the present embodiment described above, predetermined position coordinates are obtained using one reference marker 24 provided in the processing chamber 22, but two reference markers 24 provided in the processing chamber 22 are used. By doing so, it becomes possible to separate and obtain the shift in the installation position and the shift in orientation, and the second shift amount can be obtained with high accuracy in a short time. FIG. 5 shows an example in which two reference markers 24 are provided in the processing chamber 22 and the cameras 23 are arranged corresponding to each of the two reference markers 24. In the case of obtaining the predetermined position coordinates using the two reference markers 24, the deviation of the installation position and the deviation of the orientation can be separately obtained. Therefore, the first deviation amount is obtained by only rough adjustment by the origin sensor. Even if a value is used, the robot can be moved with sufficient precision when the teaching data is reused. If a camera 23 having a sufficiently wide field of view can be used, two reference markers 24 can be photographed so that a measuring jig can be taken using a single camera 23, and from the photographed image, the installation position is shifted. It can be obtained by separating the misalignment of and orientation. If a rectangular measuring jig is used, when two reference markers 24 are used, the reference markers 24 may be arranged corresponding to each of the vertices on both sides of one diagonal of the jig. By doing in this way, since the distance between the two positions for detecting the edge of the jig can be lengthened, it is possible to detect a shift in orientation with high accuracy.

The robot shown in Fig. 1 is a horizontal articulated robot in which the arms 12, 13 and the hand 14 are connected in this order to the base 11, but the robot to which the position information restoration method of the present invention can be applied is limited to this. It does not become. The robot disclosed in Patent Document 5 includes a base, a base-side link connected to the base, an arm-side link connected to the tip of the base-side link, an arm connected to the tip of the arm-side link, and a hand connected to the tip of the arm. , It is a horizontal articulated robot provided on the base and provided with a mechanism for raising and lowering the base-side link, and the movement of the tip end of the arm-side link is regulated by the link mechanism, but the present invention can also be applied to such a robot. Furthermore, the present invention can be applied to a vertical articulated robot or the like.

11: base
12, 13: cancer
14: hand
15: motor
16: encoder
21: transfer room
22: processing room
23: camera
24: reference marker
31: work
40: robot controller
41: bus
42: servo circuit
43: CPU
44: memory unit
51: teaching data storage unit
52: origin offset storage unit
53: predetermined position coordinate storage unit
60: teaching pendant

Claims (9)

It is a method of restoring positional information of a robot used in a processing apparatus having a plurality of processing chambers and supporting an object and conveying between the plurality of processing chambers based on teaching data,
The robot includes a base installed in the processing apparatus, a hand supporting the object, and at least one arm interposed between the base and the hand,
A part of the robot is replaced, part or all of the robot is reassembled, or the robot is relocated as a robot exchange, and before the robot exchange is executed, the robot's origin offset and the hand are extended to move to a predetermined position. A step of storing predetermined position coordinates indicating the position and posture of the robot when ordered, and
A step of acquiring an origin offset of the robot after replacement of the robot, and storing a first amount of shift, which is a difference between the origin offset before replacement of the robot and the origin offset after replacement of the robot;
After the robot exchange, the hand is extended to move the robot to the predetermined position to obtain the predetermined position coordinates, and a second based on the difference between the predetermined position coordinates before the robot exchange and the predetermined position coordinates after the robot exchange Have a process of calculating and storing the amount of misalignment,
Separately managing the first amount of misalignment and the second amount of misalignment,
Moving the robot to the predetermined position based on the teaching data actually used in the robot,
Until the deviation of the predetermined position coordinates before and after the robot exchange falls within the allowable range, the teaching data is corrected using the first deviation amount and the second deviation amount, and based on the corrected teaching data, the robot And repeating recalculation of the second shift amount by moving from the origin position to the predetermined position. The method of claim 1,
The processing unit is provided with one reference marker, and at least a part of the object mounted on the hand and the reference marker are imaged by a visual sensor to obtain the position of the object, thereby obtaining the predetermined position in a coordinate system separate from the robot. A method of restoring location information to obtain location coordinates. The method of claim 1,
After the robot is exchanged, the robot is moved to the origin position by rough adjustment by an origin sensor provided in the robot and fine adjustment by a fitting means that regulates the mutual positions of structures included in the robot, A method for restoring positional information, for acquiring the origin offset. The method of claim 1,
The processing device is provided with two reference markers, and at least a part of the object mounted on the hand and the reference marker are imaged by a visual sensor to obtain the position of the object, thereby obtaining the position of the object in a coordinate system separate from the robot. A method of restoring location information, acquiring predetermined location coordinates. The method of claim 4,
The object has a rectangular shape, and the two reference markers are provided at positions respectively corresponding to both ends of one diagonal line of the object when the robot is at the predetermined position. The method according to claim 2 or 4,
The reference marker is provided in any one of the plurality of processing chambers. The method of claim 6,
The predetermined position is a position when the hand is furthest from the base in the processing chamber in which the reference marker is provided. delete delete

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