JP7080068B2 - How to restore the location information of the robot - Google Patents

Description

The present invention relates to a position information restoration method that enables a previously taught data to be used by a robot when exchanging equipment in the robot, reassembling or relocating the robot, and the like.

In a robot that operates based on teaching data, equipment such as motors and arms constituting the robot may be replaced, and the robot itself may be reassembled or relocated as necessary. When the equipment is replaced, reassembled, or relocated, the amount of error related to the assembly and installation of the robot changes, so it is necessary to re-teach the robot before performing work with the robot again. However, since it takes a lot of time and labor to teach a robot, it is desired that the previous teaching data can be used even when the equipment is replaced, the robot is reassembled or relocated. Patent Document 1 relates to a robot that processes a work held by a holding device, and attaches three positions of the holding device or the work held by the holding device to the arm of the robot before and after the robot is relocated. It discloses that the teaching data is modified so that the change in the relative position between the robot and the holding device is compensated based on the change in the measurement result before and after the relocation of the robot by measuring with the visual sensor.

In a robot, the position of each axis (especially the rotation 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 It will shift. This is also the reason why the previous teaching data cannot be used after the equipment is replaced. However, in Patent Document 2, pin holes are provided in each pair of structures (for example, an arm) constituting the joint axis of the robot. A method of defining a reference position by inserting a pin penetrating into each pin hole, or a proximity sensor corresponding to a V-shaped groove is provided in one structure constituting the joint axis and a V-shaped groove is provided in the other structure. Discloses a method of specifying a reference position by a signal from a proximity sensor.

When the equipment is replaced, the robot itself is reassembled or relocated, and the robot is calibrated in order to cope with changes over time. When calibration is performed, the mechanical 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 modified and used based on the mechanism parameters before calibration and the mechanism parameters after calibration.

By the way, among various robots, the horizontal articulated robot is used for transporting, for example, a semiconductor wafer or a glass substrate. Patent Documents 4 and 5 show examples of a horizontal articulated robot for transporting a semiconductor wafer, a glass substrate, or the like as a transporting object. With the increase in the size of the object to be transported by the horizontal articulated robot and the complexity of the process performed on the object to be transported, the size of the horizontal articulated robot itself has also increased, and the transport distance of the object to be transported has also become long. .. As the size of the horizontal articulated robot becomes larger, in order to ship the robot and install it at the demand destination, it becomes necessary to complete and adjust the robot, disassemble the robot once, transport it, and reassemble it at the installation destination. ing.

Japanese Patent No. 3733364 Japanese Patent No. 481995 Japanese Unexamined Patent Publication No. 2017-213668 Japanese Unexamined Patent Publication No. 2015-139854 Japanese Patent No. 5199117

Patent Document 1-3 makes it possible to use the previous teaching data without re-teaching even when the equipment in the robot is replaced, the robot itself is reassembled or relocated, and the robot is recalibrated. The method is disclosed. In each of the methods of Patent Document 1-3, a set of correction data (data relating to a position shift regarding a specific holding device before and after relocation in the case of Patent Document 1, and data relating to a reference position in the case of Patent Document 2) are used. In the case of Patent Document 3, it depends on the data regarding the deviation of the mechanical parameters before and after the calibration). However, when the robot becomes large and its moving range becomes large like a horizontal articulated robot for transportation, the teaching data can be sufficiently corrected by the method of Patent Document 1-3. It cannot be done, and as a result, it may be forced to re-teach. In addition, if there is a problem with the correction data used to correct the teaching data, it is difficult to deal with the cause of the problem, and it is also difficult to verify the validity of the correction data. Will require a great deal of effort.

An object of the present invention is that in a robot such as a large horizontal articulated robot for transportation, re-teaching is not required when exchanging equipment constituting the robot, reassembling or relocating the robot, and solving problems in data. The purpose is to provide a location information restoration method that can easily verify the validity.

The position information restoration method of the present invention is used in a processing apparatus having a plurality of processing chambers, and is a method of restoring the position information of a robot that supports an object and conveys it between a plurality of processing chambers based on teaching data. The robot is provided with a base installed in a processing device, a hand supporting an object, and at least one arm interposed between the base and the hand, and a part of the robot can be replaced. Reassembly of part or all of the robot, or relocation of the robot is regarded as robot replacement, and the origin offset of the robot and the position and posture of the robot when the hand is extended and moved to the predetermined position are indicated before the robot replacement is executed. The process of storing the position coordinates and the process of acquiring the origin offset of the robot after the robot exchange and storing the first deviation amount which is the difference between the origin offset before the robot exchange and the origin offset after the robot exchange. After the robot exchange, the hand is extended to move the robot to the predetermined position to acquire the predetermined position coordinates, and the second deviation is based on the difference between the predetermined position coordinates before the robot exchange and the predetermined position coordinates after the robot exchange. It has a step of calculating and storing the amount, and manages the first deviation amount and the second deviation amount separately.

In the present invention, the correction amount used for correcting the teaching data is divided into two, a first deviation amount based on the origin offset and a second deviation amount based on predetermined position coordinates, and these deviation amounts are managed separately. When there is an abnormality in the deviation amount, it is possible to easily determine whether the abnormality is present and which deviation amount the abnormality is in. Further, even if data loss occurs in the process of calculating the deviation amount, if the calculation of the first deviation amount is completed, the first deviation amount can be used as it is and the second deviation amount can be calculated. , The time for calculating the correction amount can be shortened.

In the first aspect of the position information restoration method of the present invention, the processing device 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 acquire the position of the object. By doing so, a predetermined position coordinate in a coordinate system separate from the robot, for example, a coordinate system of the processing device is acquired . The deviation that occurs in the predetermined position coordinates when the robot is moved to the predetermined position after the robot is replaced is mainly the displacement in the plane where the robot is installed (the deviation in the XY coordinates with the installation plane of the robot as the XY plane) and the orientation of the robot. Although it is caused by the deviation (angle deviation), the effect of the orientation deviation is larger than the position deviation in a large robot, so if the second deviation amount is calculated by focusing on the orientation deviation, 1 It is sufficient to use only one reference marker, and the calculation for calculating the second deviation amount can be simplified.

In the present invention, after the robot is replaced, the robot is moved to the origin position by rough adjustment by the origin sensor provided in the robot and fine adjustment by the fitting means for regulating the position between the structures included in the robot. You can move it to get the origin offset. By moving the robot to the origin position in such a procedure when acquiring the origin offset, it becomes possible to accurately align the robot with the origin position by mechanical means in the robot. As a result, even when only one reference marker is used, when the teaching data is corrected based on the first deviation amount and the second deviation amount, the robot accurately moves to a desired position based on the teaching data. become able to.

In the second aspect of the position information restoration method of the present invention, 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 acquire the position of the object. By doing so, a predetermined position coordinate in a coordinate system separate from the robot, for example, a coordinate system of the processing device is acquired . When two reference markers are provided, the position deviation and the angle deviation included in the second deviation amount can be separated. Therefore, even if there is some error in the origin offset, the first deviation amount and the second deviation amount are provided. The teaching data modified based on the amount and the amount allows the robot to be accurately moved to the desired position. When two reference markers are provided, the shape of the object is square, and two reference markers are provided corresponding to each of the positions that are both ends of one diagonal line of the object when the robot is in a predetermined position. It is preferable to provide it. By providing the reference markers corresponding to both ends of the diagonal line, the distance between the reference markers becomes large, and the deviation of the orientation in the robot can be detected accurately.

In the present invention, it is preferable to provide a reference marker in any one of the plurality of treatment chambers. By using the reference marker provided in the processing chamber actually used in the processing apparatus, it becomes possible to correct the teaching data for the deviation in the processing chamber actually used. When the reference marker is provided in the processing chamber as described above, it is preferable that the predetermined position is the position when the hand is farthest from the base in the processing chamber. By extending the arm and hand of the robot and setting the position where the hand is farthest from the base in the processing room as a predetermined position, it becomes possible to detect the deviation of the orientation of the robot as a large value, so the teaching data can be corrected accurately. You will be able to do it.

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

According to the present invention, it is not necessary to re-instruct when exchanging the equipment constituting the robot, reassembling or relocating the robot, and it becomes possible to easily solve the defect in the data and verify the validity. ..

It is a figure which shows an example of a robot, (a) is a plan view, (b) is a front view, (c) is a front view of a robot at the origin position. It is a block diagram which shows the circuit structure of a robot and a robot controller. It is a figure which shows the processing apparatus provided with the robot shown in FIG. 1, and (b) is the figure which shows the cross section of the processing chamber schematically. It is a flowchart which shows the operation of the position information restoration method based on this invention. It is a figure which shows typically the processing chamber of another example.

Next, a preferred embodiment of the present invention will be described with reference to the drawings. Before explaining the position information restoration method based on the present invention, first, an example of a robot to which the position information restoration method is applied will be described.

FIG. 1 shows an example of a robot to which the position information restoration method based on the present invention is applied. 1 (a) and 1 (b) are a plan view and a front view showing a robot in a state where an arm and a hand are extended. The robot shown in FIG. 1 is similar to the horizontal articulated robot for transportation described in Patent Document 4, and has a base 11, a first arm 12 attached to the base 11, and a first arm. It includes a second arm 13 attached to the tip of the arm 12 and a hand 14 attached to the tip of the second arm 13. The hand 14 holds a semiconductor wafer, a glass substrate, or the like, which is an object to be conveyed, and is formed in a fork shape. The first arm 12 is rotatable about the axis A with respect to the base 11, the second arm 13 is rotatable about the axis B with respect to the first arm 12, and is rotatable with respect to the second arm 13. The hand 14 is rotatable around the axis C. The robot is equipped with a motor for each axis in order to enable rotation around the axes A to C, which are the joint axes of the robot. Further, the robot is provided with a mechanism provided on the base 11 to raise and lower the first arm 12 in the Z direction shown in the drawing, and this raising and lowering mechanism is also driven by the raising and lowering motor. The axes A to C are all parallel to the Z direction. Each of the base 11, the arms 12, 13 and the hand 14 is a structure included in the robot.

The robot shown in FIG. 1 has an origin position that is a reference for the operation of the robot. At the origin position, the robot has an arm and a hand in a predetermined folded posture. FIG. 1C shows the posture of the robot at the origin position, and the second arm 13 and the hand 14 are folded so that the second arm 13 and the hand 14 overlap on the first arm 12.

A robot controller is provided to control the robot shown in FIG. FIG. 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 for the axes A to C and the elevating mechanism, and these motors 15 have an encoder 16 for measuring the rotation angle of the motor 15. Each is attached.

The robot controller 40 performs calculations necessary for the operation and control of the robot, the bus 41 used for transmitting various signals and data, the servo circuit 42 provided for each motor 15 and driving the motor 15. Each servo circuit 42 includes a CPU (central processing unit) 43 that outputs commands, and a storage unit 44 that stores data necessary for calculation and control by the CPU 43. The storage unit 44 includes a teaching data storage unit 51 that stores teaching data as a storage area or a file, an origin offset storage unit 52 that stores the origin offset, and a predetermined position coordinate storage unit 53 that stores predetermined position coordinates. It is set. The origin offset and 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. A camera 23, which is a visual sensor, and a teaching pendant 60 used for teaching the robot are connected to the robot controller 40, and these are connected to the bus 41 via an interface circuit (not shown).

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

As shown in FIG. 3B, a reference marker 24 is attached to the ceiling surface of the processing chamber 22 used for carrying in / out the work 31 to and from the outside of the manufacturing system among the plurality of processing chambers 22. A camera 23 is provided on the floor surface of the processing chamber 22 so as to photograph the reference marker 24. The camera 23 is also depicted in FIG. 3 (a). The camera 23 and the reference marker 24 are used to determine whether or not the work 31 placed on the robot's hand 14 is placed in the correct position on the hand 14. The robot is moved to the processing chamber 22 provided with the camera 23 and the reference marker 24 based on the teaching data, and at that time, the reference marker 24 is photographed so that the edge of the work 31 is reflected by the camera 23. Therefore, it is possible to know whether or not the work 31 is correctly placed on the hand 14, and in what direction and how much the work 31 is displaced from the original position. When the mounting position of the work 31 deviates from the original position, the mounting position of the work 31 can be corrected by a position correction device (not shown).

Next, the position information restoration method in the embodiment of the present invention will be described. The position information restoration method of the present embodiment is to replace, reassemble, or relocate the robot itself when the equipment such as the motor or arm constituting the robot is replaced, or when the robot itself is reassembled or relocated. The teaching data previously used in the robot can be used after replacement, reassembly, and relocation without re-teaching. In the following, the replacement of equipment in a robot, the reassembly and 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 position of each motor 15 of the robot is 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 assembled state of the motor 15 with respect to the arms 12 and 13 and the hand 14, and the assembled state between the motor 15 and the encoder 16, the value of the rotation position output from the encoder 16 is zero even if the robot is in the origin position. It is not always the case. The rotation position measured by the encoder 16 when the robot is at the origin position is called the origin offset. When moving the robot based on the teaching data, compensation is performed by the origin offset after assuming that the rotation position at the origin position is zero in the teaching data, or the rotation position at the origin position is the origin offset. It is necessary that the teaching data is described as a value to be shown. 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 due to the robot exchange.

When finding 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 the robot is replaced is not yet known, the robot cannot be moved to the origin position by an origin return command or the like for the robot. Therefore, the robot may be moved to the origin position by using the teaching pendant while visually observing the robot. In order to move the robot to the origin position more accurately, for example, as described in Patent Document 2, pin holes for restricting the posture of the robot to the posture at the origin position are provided in the arms 12, 13 and the hand 14. The robot may be fixed at the origin position by providing and inserting a jig pin into the pin hole. When a jig pin is used, an origin sensor is provided on one of two structures (arms 12, 13 and a hand 14) that share a joint axis separately from the encoder 16, and a groove or protrusion that can be detected by the origin sensor is provided on the other. It is possible to make a rough adjustment based on the output of the origin sensor, and then make fine adjustments to slowly move the robot to the position where the jig pin fits in the pin hole, and mechanically move the robot to the origin position. .. The jig pin and the pin hole function as a fitting means for regulating the position between the structures (here, the base 11, the arms 12, 13 and the hand 14) included in the robot.

By the way, the origin position is a state in which the arms 12, 13 and the hand 14 of the robot are folded, and in the case of a robot having a long arm or hand such as a transport robot, the arm 12, just by compensating for the change in the origin offset, When the 13 and the hand 14 are extended and attempted to move, it is not always possible to accurately move to the desired position. This is because the robot installation position and orientation may shift due to robot replacement. Therefore, in the present embodiment, the arms 12, 13 and the hand 14 of the robot are extended and moved to a predetermined position based on the teaching data before and after the robot exchange. Then, in an external coordinate system (for example, a coordinate system defined in the processing chamber 22) that is separate from the coordinate system of the robot itself, coordinates indicating the position and posture of the robot are obtained. These coordinates are called predetermined position coordinates. Since the predetermined position coordinates are for compensating for the deviation that cannot be compensated by the origin offset measured with the arms 12, 13 and the hand 14 folded, the arms 12, 13 and the hand 14 are extended as much as possible. Moreover, it is preferable to measure at a position as far as possible from the base 11 of the robot. Therefore, in the present embodiment, the predetermined position coordinates are measured by 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 transport chamber 21.

In the measurement of the predetermined position coordinates, the measuring jig is placed at the correct position of the hand 14 as the work 31, and the hand 14 is moved to the processing chamber 22 based on the teaching data with the measuring jig mounted. The camera 24 takes a picture so that the measuring jig is reflected in the image. In the present embodiment, for example, a square-shaped jig is used as the measuring jig, the edge of the jig is extracted from the image taken by the camera 24, and the image of the reference marker 24 and the image of the edge of the jig are taken. The coordinates of the edge of the jig are obtained from the positional relationship with the robot, and this is used as the predetermined position coordinates of the robot. At this time, the coordinates of the position of the apex of the measuring jig which is a quadrangle may be obtained, or in addition to the coordinates of the apex, the orientations of the two sides connected to the apex are acquired as an indicator of the posture of the robot. May be good. Since the reference marker 24 is fixed to the processing chamber 22, the coordinates of the edge of the jig obtained here, that is, the predetermined position coordinates, indicate the position of the robot in the external coordinate system. The reason why the robot is moved based on the teaching data in the measurement of the predetermined position coordinates is to eliminate the influence of the backlash.

In the position information restoration method of the present embodiment, the amount of change in the origin offset before and after the robot exchange is defined as the first deviation amount, and the amount of change in the predetermined position coordinates before and after the robot exchange is defined as the second deviation amount. The methods described in Patent Documents 1 and 3 are, after all, a method of measuring a value corresponding to the sum of the first deviation amount and the second deviation amount and using it for correcting the teaching data, and are described in Patent Document 2. The method described relates to the measurement of the first deviation amount. On the other hand, in the present embodiment, when the teaching data is reused after the robot is replaced, the teaching data is corrected by using both the first deviation amount and the second deviation amount, but the first deviation amount and the second deviation amount are used. 2 The amount of deviation is managed separately. In the storage unit 44, the origin offset before and after the robot exchange and the first deviation amount calculated from the origin offset are stored in the origin offset storage unit 52, and the predetermined position coordinates before and after the robot exchange and the second deviation amount calculated from the predetermined position coordinates are the predetermined position coordinates. It is stored in the storage unit 53.

In the present embodiment, the first deviation amount and the second deviation amount are managed separately. When both are managed as one, even if there is an abnormality in these deviation amounts, the abnormality is found. This is because it becomes difficult to determine which deviation amount has an abnormality. The difference in the length of the arm before and after the replacement may affect the second deviation amount, but the difference in the installation position and orientation of the robot is greater than the possible difference in the length of the arm. The second deviation amount may be considered to be the deviation amount related to the position of the robot with respect to the external coordinate system. On the other hand, the first deviation amount is the deviation amount related to the coordinates of the robot itself. Therefore, there is no inconvenience in managing these deviation amounts separately. Further, even if data is lost due to, for example, a voltage abnormality in the process of acquiring the first deviation amount and the second deviation amount, if the calculation of the first deviation amount is completed, the first time is again. It is not necessary to start over from the beginning, and it can be performed from the calculation of the second deviation amount by using the already calculated first deviation amount as it is.

Here, the second deviation amount will be examined. The second deviation amount has a component caused by the deviation of the robot installation position on the plane on which the robot is installed and the deviation of the direction of the robot. The goal of this embodiment is to reuse the teaching data without re-teaching after replacing the robot, and when the teaching data is reused, the error of the position of the hand 14 in each processing chamber 22 is set to be within a predetermined value. It is to be. For example, a deviation of 1 mm at the robot installation position is only a deviation of 1 mm at the position of the hand 14, but the sum of the lengths of the robot arms 12, 13 and the hand 14 is as large as 3 m. Considering the transfer robot, a deviation of 0.1 ° in the direction 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 installation position error (deviation of the center position of the robot) to 1 mm or less, but it is difficult to set the orientation error to 0.1 ° or less. Therefore, it can be considered that the second deviation amount corrects the deviation of the orientation of the robot after the robot is replaced. If so, the second deviation amount is calculated by a simple calculation using one reference marker 24. Will be able to be asked. Then, by using the accurately obtained first deviation amount and the second deviation amount calculated using one reference marker 24, the teaching data used before the robot replacement is corrected, and the teaching is performed. Data can be reused.

In the present embodiment, the second deviation amount is determined by using the camera 23 and the reference marker 24 provided in any of the processing chambers 22, but the processing chamber 22 provided with the camera 23 and the reference marker 24 is used for teaching data. It is preferable that the processing chamber 22 is actually used when the robot is moved based on the above. Further, when the second deviation amount is obtained from the predetermined position coordinates, the teaching data is corrected by using the first deviation amount and the second deviation amount, and after returning to the origin position once, it is moved to the above-mentioned predetermined position again to be predetermined. The position coordinates are obtained, and if the difference between the predetermined position coordinates obtained last time and the predetermined position coordinates obtained this time is within the allowable value, the second deviation amount is determined. If not, the second deviation is determined by the predetermined position coordinates obtained this time. By repeating updating the amount, the correction accuracy when reusing the teaching data can be improved.

FIG. 4 shows an example of processing by the position information restoration method of the present embodiment. First, in step 101, the origin offset before the robot exchange is stored in the origin offset storage unit 52. When a robot is installed, the origin offset should normally be obtained by adjusting the origin of the robot, so that value may be used. Next, in step 102, a jig for measurement is attached to the robot as a work 31, the robot is moved to the above-mentioned predetermined position based on the teaching data, and the edge of the jig is detected using the camera 23 and the reference marker 24. To obtain the predetermined position coordinates. The predetermined position coordinates obtained here are set as the position P, and are stored in the predetermined position coordinate storage unit 53. This is the preparatory stage before the robot is replaced, and then in step 103, the robot is replaced, that is, the robot is replaced with a device such as a motor or an arm, and the robot itself is reassembled or relocated.

After the robot exchange is completed, 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 obtained. The difference in the origin offset before and after the robot replacement stored in the storage unit 52 is obtained as the first deviation amount and stored in the origin offset storage unit 52. Subsequently, in step 106, the same measurement jig as that 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 deviation amount, and the same as described above. The predetermined position coordinates are obtained, and the predetermined position coordinates at this time are stored in the predetermined position coordinate storage unit 53 as the position Q. In step 107, the second deviation amount is obtained 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 then the robot is moved to a predetermined position from the origin position using the teaching data corrected based on the first deviation amount and the second deviation amount. The predetermined position coordinates are obtained in the same manner as described above, and the predetermined position coordinates at this time are stored 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 the robot replacement and the position R obtained this time exceeds the allowable value. When the allowable value is exceeded, the second deviation amount is not accurately obtained. Therefore, in step 110, the second deviation amount is recalculated based on the difference between the position P and the position R, and the predetermined position coordinates are stored. It is stored in the unit 53. In the recalculation of the second deviation amount, the deviation amount exceeding the permissible value occurred in the position P and the position R in the second deviation amount before the recalculation, so the second deviation amount is corrected so as to eliminate this deviation. Performs an operation to find the value to be used. After the execution of step 110, the process returns to step 108, and the processes of steps 108 to 110 are repeated until the difference between the position P and the position R is within the allowable value. If the difference between the position P and the position R in step 109 is within the allowable value, it is assumed that the second deviation amount has been determined, and the process ends.

After the first deviation amount and the second deviation amount are determined as described above 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 replacement is used. By making corrections based on the first deviation amount and the second deviation amount, the teaching data can be continued to be used even after the robot is replaced.

According to the embodiment described above, the first deviation amount based on the origin offset and the second deviation amount based on the predetermined position coordinates are separately calculated, stored, and managed to detect an abnormal value in the deviation amount. 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 after the robot exchange without re-teaching. Will also be available. Further, the robot controller 40 shown in FIG. 2 is designed so that the origin offset and the predetermined position coordinates can be managed separately, but the hardware configuration is not different from that of a general robot controller. The method of restoring the position information of the form can be realized by using a general robot controller.

In the position information restoration method of the present embodiment described above, the predetermined position coordinates are obtained by using one reference marker 24 provided in the processing chamber 22, but the two reference markers 24 provided in the processing chamber 22 are used. By using it, it becomes possible to separately acquire the deviation of the installation position and the deviation of the orientation, and it becomes possible to accurately obtain the second deviation amount in a short time. FIG. 5 shows an example in which the camera 23 is arranged corresponding to each of the two reference markers 24, assuming that the processing chamber 22 is provided with the two reference markers 24. When the predetermined position coordinates are obtained using the two reference markers 24, the deviation of the installation position and the deviation of the orientation are obtained separately. Therefore, the first deviation amount is obtained only by rough adjustment by the origin sensor. Even if the values are used, the robot can be moved with sufficient accuracy when the teaching data is reused. If a camera 23 having a sufficiently wide field of view can be used, the two reference markers 24 can be photographed by using a single camera 23 so that the measuring jig is reflected, and from the photographed image, the two reference markers 24 can be photographed. It is possible to separately obtain the deviation of the installation position and the deviation of the orientation. If a jig for measuring a quadrangle 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 line of the jig. By doing so, the distance between the two positions for detecting the edge of the jig can be lengthened, so that the deviation of the orientation can be detected 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 to the base 11 in this order, but the robot to which the position information restoration method of the present invention can be applied is to this. Not limited. The robot shown 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, and an arm connected to the tip of the arm-side link. It is a horizontal articulated robot equipped with a hand connected to the tip of the arm and a mechanism provided on the base to raise and lower the base side link, and the movement of the tip of the arm side link is regulated by the link mechanism. The present invention is also applicable to such a robot. Furthermore, the present invention can be applied to vertical articulated robots and the like.

11 ... Base; 12, 13 ... Arm; 14 ... Hand; 15 ... Motor; 16 ... Encoder; 21 ... Transport room; 22 ... Processing room; 23 ... Camera; 24 ... Reference marker; 31 ... Work; 40 ... Robot controller 41 ... Bus; 42 ... Servo circuit; 43 ... CPU; 44 ... Storage unit; 51 ... Teaching data storage unit; 52 ... Origin offset storage unit; 53 ... Predetermined position coordinate storage unit; 60 ... Teaching pendant.

Claims (8)

A method for restoring position information of a robot that is used in a processing apparatus having a plurality of processing chambers and that supports an object and conveys the object between the plurality of processing chambers based on teaching data.
The robot includes a base installed in the processing device, a hand that supports the object, and at least one arm that is interposed between the base and the hand.
The replacement of a part of the robot, the reassembly of a part or the whole of the robot, or the relocation of the robot is regarded as the robot replacement, and before the execution of the robot replacement, the origin offset of the robot and the hand are extended and predetermined. The process of memorizing the position and the predetermined position coordinates indicating the posture of the robot when the robot is moved to the position, and
A step of acquiring the origin offset of the robot after the robot exchange and storing a first deviation amount which is a difference between the origin offset before the robot exchange and the origin offset after the robot exchange.
After the robot exchange, the hand is extended to move the robot to the predetermined position to acquire the predetermined position coordinates, and the predetermined position coordinates before the robot exchange and the predetermined position coordinates after the robot exchange are obtained. The process of calculating and storing the second deviation amount based on the difference between
Have,
The first deviation amount and the second deviation amount are managed separately, and the first deviation amount and the second deviation amount are managed separately .
The processing device 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 acquire the position of the object, thereby being separate from the robot. A position information restoration method for acquiring the predetermined position coordinates in a coordinate system . After the robot is replaced, the robot is moved to the origin position by rough adjustment by the origin sensor provided in the robot and fine adjustment by the fitting means for regulating the position between the structures included in the robot. The position information restoration method according to claim 1 , wherein the robot is moved to obtain the origin offset. A method for restoring position information of a robot that is used in a processing apparatus having a plurality of processing chambers and that supports an object and conveys the object between the plurality of processing chambers based on teaching data.
The robot includes a base installed in the processing device, a hand that supports the object, and at least one arm that is interposed between the base and the hand.
The replacement of a part of the robot, the reassembly of a part or the whole of the robot, or the relocation of the robot is regarded as the robot replacement, and before the execution of the robot replacement, the origin offset of the robot and the hand are extended and predetermined. The process of memorizing the position and the predetermined position coordinates indicating the posture of the robot when the robot is moved to the position, and
A step of acquiring the origin offset of the robot after the robot exchange and storing a first deviation amount which is a difference between the origin offset before the robot exchange and the origin offset after the robot exchange.
After the robot exchange, the hand is extended to move the robot to the predetermined position to acquire the predetermined position coordinates, and the predetermined position coordinates before the robot exchange and the predetermined position coordinates after the robot exchange are obtained. The process of calculating and storing the second deviation amount based on the difference between
Have,
The first deviation amount and the second deviation amount are managed separately, and the first deviation amount and the second deviation amount are managed separately.
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 acquire the position of the object, thereby being separate from the robot. A position information restoration method for acquiring the predetermined position coordinates in a coordinate system. 3. The object is rectangular, and the two reference markers are provided at positions corresponding to both ends of one diagonal of the object when the robot is in the predetermined position. The location information restoration method described in. The position information restoration method according to any one of claims 1 to 4 , wherein the reference marker is provided in any one of the plurality of processing chambers. The position information restoration method according to claim 5 , wherein the predetermined position is a position when the hand is farthest from the base in the processing chamber provided with the reference marker. The position information restoration method according to any one of claims 1 to 6 , wherein the robot is moved 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 is 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 position information restoration method according to claim 7 , wherein the robot is repeatedly moved from the origin position to the predetermined position and the second deviation amount is recalculated.

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