JP2020179462A - Robot original point setting method and robot original point setting system - Google Patents

Abstract

To improve accuracy in setting an original point of a shaft of a robot regardless of skill level of a worker.SOLUTION: A robot system 1 comprises a robot 2 having a plurality of shafts, a controller 3 and a display part 16, which is a system for performing original point setting that calibrates a relation between a detected value by an encoder 15, which detects a rotation angle of a motor 13 that drives a target shaft while rotating the target shaft so that an angle of the target shaft, a shaft targeted for the original point setting is equal to a reference angle and an actual angle of the target shaft. The controller 3 comprises a shaft-designation processing part 19, a display processing part 20 and an execution processing part 21. The shaft-designation processing part 19 designates the target shaft. The display processing part 20 makes the display part 16 display a posture display representing a posture of the robot 2 in which the angle of the target shaft is equal to the reference angle and an angle of a non-target shaft that is not designated as the target shaft is equal to a current angle detected based on the detected value by the encoder 15. The execution processing part 21 executes original point setting according to operation for execution by a worker.SELECTED DRAWING: Figure 2

Description

The present invention relates to a robot origin setting method and a robot origin setting system for origining the axes of a robot having a plurality of axes.

For example, in an industrial robot system, it is necessary to calibrate the relationship between the position information of each axis recognized by the controller and the actual position of the robot arm, in other words, to calibrate the origin position of each axis of the robot. .. In this specification, such calibration of the origin position may be referred to as origin determination. Origin setting is the work of aligning the origin of the robot arm (axis) with the origin of the encoder that detects the rotation angle of the motor that drives the robot arm.

Such origination is basically performed at a factory at a stage before shipment, as described in Patent Document 1, for example. However, even after the robot etc. is shipped from the factory and installed at the installation site, if one or both of the motor and the reducer break down and are replaced, the encoder battery will run out. In such a case, it was necessary to perform the above-mentioned origin setting again.

Japanese Unexamined Patent Publication No. 2009-274188

When the origin is set, the worker who performs the origin setting first rotates the robot arm so that the angle of the axis to be the origin is set to a predetermined reference angle. In this specification, the axis that is the target of origin determination may be referred to as the target axis. Data for finding the origin based on the difference between the reference angle and the detection angle calculated from the detection value of the encoder in a state where the angle of the target axis is rotated so as to match the reference angle in this way. That is, correction data corresponding to the reference angle and the detection angle is generated, and the correction data is stored in the controller. The controller can accurately detect the actual angle of the robot arm based on the detection value of the encoder and the correction data.

The above-mentioned reference angle can be determined by one of the following two methods. The first is a mechanical method. In the mechanically determined method, the angle at which the robot arm comes into contact with a predetermined object is set as the reference angle. Specifically, in the mechanical determination method, the angle when the robot arm is pressed against a mechanical structure such as a mechanical stopper (mechanical end), and the angle when the robot arm is fixed using a knock pin (positioning pin). Etc. are used as the reference angle. The second is a method of visually determining. In the method of visually determining, markings are made in advance on the two robot arms sandwiching the rotation axis to be the origin, and the markings are in a predetermined state (for example, a state in which the two marks are connected). The reference angle is 0 degrees when the robot arm is horizontal or 90 degrees when the robot arm is vertical.

Compared with the mechanical determination method, the visual determination method tends to cause variations in the angle due to the skill level of the operator, and if the operator's skill level is low, the accuracy of origin determination may be low. On the other hand, in the mechanical determination method, the angle variation due to the skill level of the operator is less likely to occur as compared with the visual determination method, so that the accuracy of origin determination can be basically improved. However, the mechanical method may cause problems in the following cases.

That is, when the robot arm is pressed against the mechanical structure, the operator determines whether the robot arm (axis) is rotated in the positive direction from the current position and pressed, or is rotated in the negative direction and pressed. It can be difficult to know exactly. For example, in a 6-axis vertical articulated robot, when the 5-axis origin is set, the pressing direction is reversed depending on whether the 4-axis angle is 0 degrees or 180 degrees.

In such a robot, the difference in the state (posture) of the robot between the case where the angles of the four axes are 0 degrees and the case where the angles of the four axes are 180 degrees can only be determined by, for example, the presence or absence of a connector, and the work experience is inexperienced. That is, it is extremely difficult for an operator with a relatively low skill level to discriminate such a difference. Therefore, when locating the origin of the five axes of such a robot, even if a worker with a relatively low skill level moves the robot arm based on the maintenance manual, for example, the target axis is set. There is a possibility of moving to an erroneous angle different from the reference angle, and as a result, the accuracy of origin setting may decrease.

As described above, conventionally, the accuracy of origin setting largely depends on the skill level of the operator who performs the work. Since the origin setting performed at the factory is usually performed by a relatively skilled worker such as a person involved in the production of robots, the accuracy can be improved, but the origin performed after shipment from the factory. Since the delivery may be performed by a relatively unskilled worker such as a robot user, it is difficult to improve the accuracy.

The present invention has been made in view of the above circumstances, and an object of the present invention is a robot origin setting method and a robot origin that can improve the accuracy of the origin of the robot axis regardless of the skill level of the operator. It is to provide a delivery system.

In the method of setting the origin of the robot according to claim 1, the operator controls the target axis so that the angle of the target axis, which is the axis to be set at the origin among the plurality of axes of the robot, becomes a predetermined reference angle. This is a method for calibrating the relationship between the detection value of the encoder that detects the rotation angle of the motor that drives the target shaft and the actual angle of the target shaft in the state of being rotated. This method includes an axis designation processing procedure for designating a target axis, a display processing procedure, and an execution processing procedure for executing origin setting according to an operation for execution by an operator.

In the display processing procedure, when the axis not specified in the axis designation processing procedure among multiple axes is set as the non-target axis, the angle of the target axis becomes the reference angle and the angle of the non-target axis is based on the detection value of the encoder. This is a procedure for displaying the attitude display indicating the posture of the robot so as to be the current angle detected by the display device. In this way, by displaying not only the posture corresponding to the target axis but also the posture corresponding to the non-target axis, the correct posture that the robot should take when performing the origin setting, in other words, the origin setting is displayed. The final posture of the robot at the time of execution will be displayed on the display device.

The operator moves (rotates) the target axis so that the actual robot takes the same posture as the displayed posture while checking the posture of the robot displayed by such a display processing procedure. Can be easily and surely fixed to the reference angle. After that, the operator can perform the origin setting in a state where the target axis is surely fixed at the reference angle by performing the operation for execution.

According to such an origin setting method, the information displayed on the display device plays a role like a work procedure manual for the origin setting work, and as a result, the worker who performs the origin setting work can read a maintenance manual or the like. It is possible to easily and surely fix the target axis to the reference angle without checking. Further, according to the above method, the operator only needs to move the target axis so that the actual robot takes the same posture as the posture displayed on the display device. Therefore, the vertical articulated robot as described above. It is possible to prevent the occurrence of an error in the rotation direction when the origin of the five axes is set.

As described above, according to the above-mentioned origin setting method, the accuracy of the origin setting of the robot axis can be improved regardless of the skill level of the operator who performs the work. Therefore, such a method of origin setting is not only applied to the origin setting performed by a relatively skilled worker performed at the factory before shipment, but also compared with the installation site such as a robot after the factory shipment. It can also be applied to origin setting performed by an operator with a low skill level (for example, a robot user), and is particularly useful in such origin setting after factory shipment.

If the worker has some experience in working with the robot, the posture display displayed by the display processing procedure may be a simple display that symbolizes the axis (joint), arm, etc. of the robot, for example. It is considered relatively easy to move the target axis so that the actual robot takes the same posture as the displayed posture. However, for workers who have little experience working with robots (such as users who have newly purchased a robot), such a simple display should take the same posture as the actual robot is displayed. It may be difficult to move the target axis.

Therefore, in the display processing procedure in the origin setting method according to claim 2, the attitude display is such that the appearance of the robot is schematically represented. In this way, the operator moves the target axis so that the appearance of the actual robot is the same as the appearance of the displayed robot while checking the posture display displayed by the display processing procedure. The shaft can be easily and surely fixed to the reference angle.

In this case, the worker only has to move the target axis so that the appearance of the robot is the same as what is displayed. Therefore, even a worker who has very little experience in working with the robot can move the target axis. It can be more easily and surely fixed to the reference angle. Therefore, according to the above method, it is possible to maintain good accuracy of origining the axis of the robot even when an inexperienced operator performs the origining work.

In the display processing procedure in the origin setting method according to claim 3, the display device displays the angles related to each of the plurality of axes. Further, in this case, the display mode of the angle of the target axis and the display mode of the angle of the non-target axis are different from each other. In this way, the operator can easily recognize which axis is the target of the current origin setting by the difference in the display mode. Therefore, according to the above method, the operator can surely move the axis that is currently the target of origin, and prevents the axis that is not the target of origin from being accidentally moved. The effect of being able to do it is obtained.

In the display processing procedure in the origin setting method according to claim 4, the attitude display is updated intermittently or continuously. According to this, even if the non-target axis moves for some reason such as an erroneous operation by the worker while the worker is rotating the target axis toward the reference angle, the non-target axis in the posture display is supported. The posture of the robot changes so as to be the same as the actual posture. As a result, according to the above method, the final posture of the robot at the time of executing the origin setting is always displayed on the display device, and the above-mentioned effect can be surely obtained.

When the reference angle corresponding to the target axis is determined by the above-mentioned mechanical determination method, the direction in which the target axis should be rotated when the origin is set is uniquely determined. Further, although the detection value of the encoder corresponding to the target axis does not show a correct value, the direction in which the target axis is rotated can be obtained from the change in the detected value. Therefore, the origin setting method according to claim 5 includes a notification processing procedure having the following contents.

That is, in the notification processing procedure, when the reference angle corresponding to the target axis is the angle when the robot arm comes into contact with a predetermined object, the target axis is rotated at the time of origin determination based on the reference angle. The direction to be made is required. Further, in the notification processing procedure, the direction in which the target axis is currently rotated is obtained based on the detection value of the encoder. Further, in the notification processing procedure, the operator is notified that there is an error in the direction in which the target axis is rotated when the respective directions do not match.

According to such a method, when the operator rotates the target axis so as to have a reference angle determined by a mechanical method, even if the target axis is rotated in an erroneous direction, the error is notified. Therefore, according to the above method, when the operator cannot understand the correct rotation direction even if the attitude display displayed on the display device is confirmed, or when the operator neglects to confirm the attitude display displayed on the display device. Also, the rotation direction of the target axis can be prompted in the correct direction. Therefore, according to the above method, it is possible to more effectively prevent the occurrence of an error in the rotation direction when the origin of the five axes of the vertical articulated robot as described above is set.

The robot origin setting system according to claim 6 is based on a technical idea common to the robot origin setting method described above. Therefore, even with such a robot origin setting system, the accuracy of the origin setting of the robot axis can be improved regardless of the skill level of the operator, as in the above-mentioned origin setting method.

The figure which shows typically the structure of the robot system which concerns on 1st Embodiment The figure which shows typically the electric structure of the robot system which concerns on 1st Embodiment The figure which shows typically the state of the robot before and after the work of rotating the wrist so that the angle of the target axis which concerns on 1st Embodiment becomes a reference angle. The figure which shows typically the processing content which is executed by the controller at the time of origin setting which concerns on 1st Embodiment. The figure which shows typically the specific example of the screen displayed by the display process which concerns on 1st Embodiment The figure which shows typically the state of the robot when the angle of the 4th axis which concerns on 1st Embodiment is 0 degree. The figure which shows typically the state of the robot when the angle of the 4th axis which concerns on 1st Embodiment is 180 degrees. The figure which shows typically the electric structure of the robot system which concerns on 2nd Embodiment

Hereinafter, a plurality of embodiments of the robot origin setting system will be described with reference to the drawings. In each embodiment, substantially the same configuration is designated by the same reference numerals and the description thereof will be omitted.
(First Embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 7.

The robot system 1 shown in FIG. 1 is, for example, a general industrial robot system, and includes a robot 2, a controller 3 that controls the operation of the robot 2, and a teaching pendant 4 for operating and displaying the robot 2. .. The robot 2 is, for example, a 6-axis vertical articulated robot.

The robot 2 has a base 5, a shoulder portion 6 rotatably supported by the base 5, a lower arm 7 rotatably supported by the shoulder portion 6 in the vertical direction, and a lower arm 7 rotatably supported by the lower arm 7. The first upper arm 8 supported, the second upper arm 9 rotatably supported by the first upper arm 8, the wrist 10 rotatably supported by the second upper arm 9 in the vertical direction, and It is composed of a flange 11 that is twistably and rotatably supported by the wrist 10. The base 5, the shoulder portion 6, the lower arm 7, the first upper arm 8, the second upper arm 9, the wrist 10 and the flange 11 function as arms of the robot 2, and the flange 11 which is the tip of the arm is not shown. It does not, but an end effector (hand) is attached.

In this case, the joint axis of the rotary joint connecting the base 5 and the shoulder portion 6 is the first axis J1, and the joint axis of the rotary joint connecting the shoulder portion 6 and the lower arm 7 is the second axis J2. The joint axis of the rotary joint that connects the lower arm 7 and the first upper arm 8 is the third axis J3, and the joint of the rotary joint that connects the first upper arm 8 and the second upper arm 9 The axis is the 4th axis J4, the joint axis of the rotary joint that connects the second upper arm 9 and the wrist 10 is the 5th axis J5, and the joint axis of the rotary joint that connects the wrist 10 and the flange 11 is Let it be the 6th axis J6.

As shown in FIG. 2, the plurality of axes J1 to J6 provided in the robot 2, and by extension, each arm 12 are driven by motors 13 provided corresponding to the respective axes J1 to J6. Further, in this case, each motor 13 drives each arm 12 (shafts J1 to J6) via, for example, a speed reducer 14 which is a gear. An encoder 15 for detecting the rotation angle of each rotation axis is provided in the vicinity of each motor 13.

The encoder 15 is, for example, an absolute encoder, and has a function of detecting a rotation angle within one rotation of the motor 13 and a function of counting and storing the number of rotations of the motor 13. The detected value of the encoder 15 includes one rotation data indicating the rotation angle within one rotation of the motor 13 and multi-rotation data indicating how many rotations the motor 13 has made. The encoder 15 is operated by the main power supply of the robot system 1 supplied from the controller 3.

Further, even when the main power supply is stopped due to the controller 3 being turned off, the encoder 15 counts and retains (stores) multi-rotation data by the backup battery built in the robot 2. It is supposed to do. In the encoder 15, when such a battery is exhausted and the battery runs out, the one-rotation data is retained, but the multi-rotation data disappears.

The teaching pendant 4 has a size that allows the user to carry or hold it in his / her hand and operate it, for example, and is formed in a thin, substantially rectangular box shape. The teaching pendant 4 has a display unit 16 made of, for example, a liquid crystal display at the center of the surface portion. Various screens are displayed on the display unit 16. The display unit 16 is an example of a display device for displaying the robot 2. The display unit 16 is composed of a touch panel. Further, the teaching pendant 4 is provided with various key switches 17 around the display unit 16. The key switch 17 and the touch switch provided on the touch panel correspond to the operation unit 18 shown in FIG. The user performs various input operations by the operation unit 18.

The teaching pendant 4 is connected to the controller 3 via a cable and executes high-speed data transfer to and from the controller 3 via a communication interface, and is input by the operation of the operation unit 18. Information such as an operation signal is transmitted from the teaching pendant 4 to the controller 3. Further, the controller 3 supplies driving power to the teaching pendant 4 together with a control signal, a display signal, and the like.

The user can execute various functions such as operation and setting of the robot 2 by using the teaching pendant 4, and for example, by operating the operation unit 18, a control program stored in advance is called to activate the robot 2. And various parameter settings can be executed. Further, the robot system 1 having such a configuration can manually operate the robot 2 to perform various teaching operations and to set the origin of the axes J1 to J6 of the robot 2. Therefore, the robot system 1 of the present embodiment corresponds to the origin setting system of the robot.

The origin setting described above is to calibrate the origin positions of the axes J1 to J6 of the robot 2. In this case, in the origin setting, the operator rotates the target axis so that the angle of the target axis, which is the target axis of the origin setting among the plurality of axes J1 to J6, becomes a predetermined reference angle. , The relationship between the detection value of the encoder 15 that detects the rotation angle of the motor 13 that drives the target axis and the actual angle of the target axis is calibrated. Details such as how to determine the reference angle are as described in the description of the prior art. The controller 3 includes a CPU, a ROM, a RAM, and the like, and has a configuration for executing the above-mentioned origin determination.

That is, as shown in FIG. 2, the controller 3 includes functional blocks such as an axis designation processing unit 19, a display processing unit 20, and an execution processing unit 21. Each of these functional blocks is realized by executing the process corresponding to the program by executing the program stored in the ROM or the like by the CPU of the controller 3, that is, it is realized by software. At least a part of each of these functional blocks may be realized by hardware.

The axis designation processing unit 19 designates a target axis according to a predetermined operation on the operation unit 18 of an operator (for example, a user) who sets the origin. Each process executed by the axis designation processing unit 19 corresponds to the axis designation processing procedure. In the following description, among the plurality of axes J1 to J6, the axis not designated by the axis designation processing unit 19 is defined as the non-target axis. The display processing unit 20 displays a posture display representing the posture of the robot 2 so that the angle of the target axis becomes the reference angle and the angle of the non-target axis becomes the current angle detected based on the detection value of the encoder 15. Display on 16.

In this case, the display processing unit 20 updates the above-mentioned attitude display intermittently, specifically, at predetermined time intervals. The display processing unit 20 may continuously update the above-mentioned attitude display. Each process executed by the display processing unit 20 corresponds to a display processing procedure.

The execution processing unit 21 executes the origin setting according to the operation for execution of the operation unit 18 of the operator. Specifically, when the operation for execution is performed, the execution processing unit 21 is based on the difference between the detection angle of the target axis and the reference angle obtained by calculating from the detection value of the encoder 15 at that time. Then, the correction data corresponding to the reference angle and the detection angle is generated, and the correction data is stored in the ROM of the controller 3 or the like. Each process executed by the execution processing unit 21 corresponds to an execution processing procedure. By performing such origin determination, the controller 3 can accurately detect the actual angles of the axes J1 to J6 based on the detection value of the encoder 15 and the correction data.

Next, the operation of the above configuration will be described.
[1] Flow of origin setting method The origin setting of each axis J1 to J6 of the robot 2 using the robot system 1 having the above configuration is performed in the following flow. Here, the flow of origin setting will be described by taking the case where the axis J5 is targeted as an example. In this case, the reference angle corresponding to the axis J5 is determined by the method of mechanically determining as described above, and is set to the angle (for example, about 122 degrees) when pressed against the mechanical end.

First, the worker who carries out the work of origining operates (rotates) the wrist 10 so that the angle of the axis J5 to be origined becomes a predetermined reference angle. In this case, as shown in the figure on the left side of FIG. 3, the angle of the axis J5 is about 0 degrees in the robot 2 in the state before the operator rotates the wrist 10. Therefore, the operator rotates the wrist 10 so that the angle of the axis J5 changes from 0 degrees to about 122 degrees, which is a reference angle.

By rotating the wrist 10 by the operator in this way, as shown in the figure on the right side of FIG. 3, the robot 2 has an angle of the axis J5 of about 122 degrees, which is a reference angle. With the wrist 10 rotated so that the angle of the axis J5 becomes the reference angle in this way, the above-mentioned correction is based on the difference between the reference angle and the detection angle calculated from the detection value of the encoder 15. Data is generated and stored.

[2] Process executed by the controller 3 at the time of origin setting The process executed mainly by the controller 3 at the time of origin setting has the contents as shown in FIG. Here, the description will be given by taking as an example the origin setting that is performed again after the robot 2 is shipped from the factory and installed at the installation destination. In this specification, the origin setting performed again in this way may be referred to as origin restoration. The series of processes related to the origin setting shown in FIG. 4 is started in response to a predetermined operation on the operation unit 18 of the operator.

First, in step S100, it is determined whether or not there is an operation for designating the axis. Here, when the operator performs an operation for designating the axis, the result is "YES" in step S100, and the process proceeds to step S200. The operation for designating the axis includes, for example, an operation of touching and selecting one of the icons representing the axes J1 to J6 displayed on the display unit 16, and the axis number displayed on the display unit 16. Various modes of operation can be applied, such as an operation of inputting a desired axis number (number) in an input field for inputting.

In step S200, the axis designated by the operator's operation is set as the target axis. After the execution of step S200, the process proceeds to step S300, and the axis not specified by the operator's operation is set as the non-target axis. By executing steps S200 and S300, each of the axes J1 to J6 of the robot 2 is classified into either a target axis or a non-target axis. The details will be described later, but the purpose of such classification is to make the display mode different between the target axis and the non-target axis. After the execution of step S300, the process proceeds to step S400, and each process (display process) described above is executed by the display processing unit 20.

When the display process is executed, the display unit 16 displays a screen as shown in FIG. The contents of such a screen will be described later. After the execution of step S400, the process proceeds to step S500, and it is determined whether or not there is an operation for executing the origin setting. Here, when the operator performs an operation for executing the origin setting, the result is "YES" in step S500, and the process proceeds to step S600. The details of the operation for executing the origin setting will be described later. In step S600, each process (execution process) described above is executed by the execution process unit 21. After the execution of step S600, a series of processes related to origin determination is completed.

[3] Screen displayed by the display process The screen displayed by executing the display process is specifically a screen as shown in FIG. In this case, it is assumed that the axes J5 are set as the target axes and the axes J1 to J4 and J6 are set as the non-target axes. As shown in FIG. 5, "recovery of origin", which is a character indicating the work currently being performed, is displayed at the left end of the area 22 at the upper part of the screen. In the area 23 provided below the area 22, the angle display 24 showing the angles (reference angle and current angle) related to each of the axes J1 to J6, the posture display 25 showing the posture of the robot 2, the execution key 26, and the execution key 26 The CANCEL key 27 is displayed.

The reference angle displayed on the angle display 24 is a predetermined angle for each of the axes J1 to J6. Therefore, the value of the reference angle displayed on the angle display 24 does not change even when the axes J1 to J6 move (rotate). The current angle displayed on the angle display 24 is an angle detected for each of J1 to J6 of each axis based on the detection value of the encoder 15 at that time. Therefore, the value of the current angle displayed on the angle display 24 changes when each of the axes J1 to J6 moves (rotates).

In the angle display 24, the display mode of the angle of the axis J5, which is the target axis, and the display mode of the angles of the axes J1 to J4 and J6, which are the non-target axes, are different from each other. Specifically, the column in which the angle of the target axis (J5) is displayed has a white background, whereas the column in which the angle of the non-target axis (J1 to J4 and J6) is displayed is The background is gray, that is, the angle of the asymmetric axis is grayed out.

At this point, the origin setting of the axis J5, which is the target axis, has not been completed, and the origin positions of the axis J5 are not consistent. Therefore, the current angle of the axis J5, that is, the angle detected based on the detection value of the encoder 15, is, for example, a structure (second upper arm 9) in which a portion (flange 11 or the like) beyond the axis J5 extends to the axis J4. It shows a number that is immersive and impossible in reality. The posture display 25 represents the posture of the robot 2 such that the angle of the target axis (J5) becomes the reference angle and the angle of the non-target axes (J1 to J4 and J6) becomes the current angle. In this case, the attitude display 25 is a display that schematically represents the appearance of the robot 2, and more specifically, the robot 2 is displayed as a three-dimensional image (3D display).

The execution key 26 and the CANCEL key 27 are both operation keys that can be touch-operated by the operator. When the execution key 26 is touch-operated, the execution processing unit 21 executes the execution process, that is, the origin is set. Then, after displaying that the origin setting is completed, the entire screen shown in FIG. 5 is closed (hidden).

As described above, in the present embodiment, the touch operation on the execution key 26 is an operation for executing the origin setting. As the operation for executing the origin setting, various modes of operation such as an operation for a specific key switch 17 can be applied. When the CANCEL key 27 is touch-operated, the entire screen shown in FIG. 5 is closed (hidden) without executing the execution process, that is, the origin setting.

As described above, the following effects can be obtained according to the present embodiment.
When the origin of the robot 2 is set using the robot system 1 of the present embodiment, the controller 3 performs a process of designating the target axis according to the operation of the operator who sets the origin, and the angle of the target axis is a reference angle. A display process for displaying the posture display representing the posture of the robot 2 such that the angle of the non-target axis becomes the current angle on the display unit 16, and an execution process for executing the origin setting according to the operation of the operator. Is executed.

In the posture display displayed by the above-mentioned display process, not only the posture corresponding to the target axis but also the posture corresponding to the non-target axis is displayed. As a result, the correct posture that the robot 2 should take when performing the origin setting, in other words, the final posture of the robot 2 when performing the origin setting is displayed on the display unit 16. While confirming the posture of the robot 2 displayed on the display unit 16 in this way, the operator moves (rotates) the target axis so that the actual robot 2 takes the same posture as the displayed posture. , The target axis can be easily and surely fixed to the reference angle. After that, the operator can perform the origin setting in a state where the target axis is surely fixed at the reference angle by performing the operation for execution.

According to the origin setting method of the present embodiment, the information displayed on the display unit 16 plays a role like a work procedure manual for the origin setting work, and as a result, the worker who performs the origin setting work , The target axis can be easily and surely fixed to the reference angle without checking the maintenance manual or the like. Further, according to the above method, the operator only needs to move the target axis so that the actual robot 2 takes the same posture as the posture displayed on the display unit 16 of the teaching pendant 4. Therefore, according to the present embodiment, as described below, it is possible to prevent the occurrence of an error in the rotation direction when the origin of the fifth axis J5 of the robot 2, which is a 6-axis vertical articulated robot, is set. Can be done.

That is, when the origin of the axis J5 of the robot 2 is set, the operator determines whether the wrist 10 is rotated in the positive direction from the current position and pressed against the mechanical end, or rotated in the negative direction and pressed against the mechanical end. , It may be difficult to grasp accurately. In the robot 2, when the origin of the axis J5 is set, the pressing direction is reversed depending on whether the angle of the axis J4 is 0 degrees or 180 degrees.

The difference in the state (posture) of the robot 2 between the case where the angle of the axis J4 is 0 degrees as shown in FIG. 6 and the case where the axis J4 is 180 degrees as shown in FIG. 7 is, for example, the connector 28. There is no choice but to discriminate by the presence or absence, and it is extremely difficult for a worker who has little work experience, that is, a worker with a relatively low skill level, to discriminate such a difference. Therefore, when the 5-axis origin of the robot 2 is set, even if a worker with a relatively low skill level moves the wrist 10 based on the maintenance manual, for example, the target axis is set to a reference angle. It may be moved to an incorrect angle different from the above, and as a result, the accuracy of origin setting may be reduced.

According to the origin setting method of the present embodiment, the final posture of the robot 2 when executing the origin setting is displayed on the display unit 16, so that when the angle of the axis J4 is 0 degrees, the wrist The posture of the robot 2 pressed by rotating 10 in the positive direction is displayed, and when the angle of the axis J4 is 180 degrees, the posture of the robot 2 pressed by rotating the wrist 10 in the negative direction is displayed. Will be done. Then, since the operator only needs to move the target axis so that the actual robot 2 takes the same posture as the posture displayed on the display unit 16, the rotation when the origin of the axis J5 of the robot 2 is set. It is possible to prevent the occurrence of an incorrect direction.

As described above, according to the origin setting method of the present embodiment, the accuracy of origin setting of the axes J1 to J6 of the robot 2 can be improved regardless of the skill level of the operator who performs the work. Therefore, such an origin setting method is applied not only to the origin setting performed by a relatively skilled worker performed at the factory before shipment, but also at the installation destination such as the robot 2 after the factory shipment. It can also be applied to origin setting performed by a relatively unskilled worker (for example, a user of robot 2), and is particularly useful in such origin setting after factory shipment.

If the worker has some experience in working with the robot 2, the posture display displayed by the display process may be a simple display in which the axis (joint), arm, etc. of the robot 2 are symbolized, for example. It is considered that it is relatively easy to move the target axis so that the actual robot 2 takes the same posture as the displayed posture. However, in the case of a worker who has little experience in working with the robot 2 (such as a user who newly purchased the robot 2), such a simple display has the same posture as the actual posture in which the robot 2 is displayed. It may be difficult to move the target axis so as to take.

Therefore, in the display process in the origin setting method of the present embodiment, as the attitude display, a display (3D display) that schematically represents the appearance of the robot 2 is performed. In this way, when the origin is set, the operator confirms the posture display displayed on the display unit 16 so that the actual appearance of the robot 2 becomes the same as the appearance of the robot 2 displayed. By moving the target axis, the target axis can be easily and surely fixed at the reference angle.

In this case, since the worker only needs to move the target axis so that the appearance of the robot 2 is the same as the displayed one, even a worker who has very little experience in working on the robot 2 is a target. The shaft can be more easily and reliably fixed to the reference angle. Therefore, according to the origin setting method of the present embodiment, it is possible to maintain good accuracy of the origin setting of the axis of the robot 2 even when an inexperienced worker performs the origin setting work.

In this case, in the display process, the display unit 16 displays the angles related to the axes J1 to J6 of the robot 2. Further, in this case, the display mode of the angle of the target axis and the display mode of the angle of the non-target axis are different from each other. Specifically, the column in which the angle of the target axis is displayed has a white background, whereas the column in which the angle of the non-target axis is displayed has a gray background.

In this way, the operator can easily recognize which axis is the target of the current origin setting by the difference in the display mode. Therefore, according to the origin setting method of the present embodiment, the operator can surely move the axis that is currently the origin setting target, and mistakenly moves the axis that is not the origin setting target. The effect of being able to prevent it from being lost can be obtained.

In this case, in the display process, the attitude display is updated intermittently or continuously, so that the following effects can be obtained. That is, even if the non-target axis moves for some reason such as an erroneous operation by the worker while the worker is rotating the target axis toward the reference angle, the robot 2 corresponding to the non-target axis in the posture display. The posture changes so as to be the same as the actual posture. As a result, according to the origin setting method of the present embodiment, the final posture of the robot 2 at the time of executing the origin setting is always displayed on the display device, and the above-mentioned effect can be surely obtained. ..

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to FIG.
As shown in FIG. 8, the robot system 31 of the present embodiment is different from the robot system 1 of the first embodiment in that the controller 32 is provided in place of the controller 3. The controller 32 is different from the controller 3 in that the notification processing unit 33 is added.

When the reference angle corresponding to the target axis is determined by the mechanical determination method described above, the direction in which the target axis should be rotated when the origin is set is positive or negative regardless of the current angle of the target axis. It will be uniquely determined in one of the directions. Further, in the period before the origin setting is executed, the detection value of the encoder 15 corresponding to the target axis does not show a correct value, but the direction in which the target axis is rotated can be obtained from the change of the detected value. Can be done. Specifically, if the change in the detected value is a positive value, the rotation direction is known to be positive, and if the change in the detected value is a negative value, the rotation direction is found to be negative.

Therefore, when the reference angle corresponding to the target axis is the angle when the arm 12 of the robot 2 comes into contact with a predetermined object (mechanical end, positioning pin, etc.), the notification processing unit 33 is based on the reference angle. Find the direction in which the target axis should be rotated when the origin is set. Further, the notification processing unit 33 obtains the direction in which the target axis is currently rotated based on the change in the detected value of the encoder 15.

Further, the notification processing unit 33 executes notification processing for notifying the operator that there is an error in the direction in which the target axis is rotated when the directions obtained as described above do not match. As the notification process, for example, a warning message indicating that the rotation direction is incorrect can be displayed on the display unit 16, an error sound or the like can be generated, and various types of notification can be adopted. Each process executed by such a notification processing unit 33 corresponds to a notification processing procedure.

As described above, the following effects can be obtained according to the present embodiment.
According to the origin setting method of the present embodiment, when the operator rotates the target axis so as to have a reference angle determined by a mechanical method, even if the target axis is rotated in the wrong direction, the error is notified. To. Therefore, according to the above method, if the operator cannot understand the correct rotation direction even after checking the posture display displayed on the display unit 16, he neglects to check the posture display displayed on the display unit 16. Even in some cases, the rotation direction of the target axis can be prompted in the correct direction. Therefore, according to the present embodiment, it is possible to more effectively prevent the occurrence of an error in the rotation direction when the origin of the five axes of the vertical articulated robot as described above is set.

(Other embodiments)
It should be noted that the present invention is not limited to each of the above-described embodiments and described in the drawings, and can be arbitrarily modified, combined, or extended without departing from the gist thereof.
The numerical values and the like shown in each of the above embodiments are examples, and are not limited thereto.

The present invention is not limited to those used in robot systems 1 and 31, which are general industrial robot systems, and displays a robot having a plurality of axes, a controller that controls the operation of the robot, and the robot. It can be applied to all robot systems equipped with a display device for the purpose.

The display device is not limited to the display unit 16 of the teaching pendant 4, and may be, for example, a display device such as a display that performs various displays based on display signals given from the controllers 3 and 32. , A display device such as a personal computer or a mobile operation terminal (for example, a smartphone, a tablet terminal, etc.) capable of communicating with the controllers 3 and 32.

The posture display displayed by the display process may be, for example, a simple display in which the axis (joint), arm, etc. of the robot 2 are symbolized. In the display process, the display mode of the angle of the target axis and the display mode of the angle of the non-target axis may be the same display mode.
In each of the above embodiments, the origin setting method of the present invention has been described by taking the case where there is one target axis as an example, but the same origin setting method can be applied even when there are a plurality of target axes.

In each of the above embodiments, a series of processes executed at the time of origin setting, that is, an axis designation process procedure, a display process procedure, and an execution process procedure are performed by the controllers 3 and 32, but a part of these processes. Alternatively, the whole may be performed by another device (for example, a mobile operation terminal used in place of the teaching pendant 4). That is, the axis designation processing unit, the display processing unit, the execution processing unit, and the like may be configured by a device different from the controllers 3 and 32.

In each of the above embodiments, the axis designation processing unit 19 executes the process of designating the target axis according to the operation of the operator on the operation unit 18, but the process of automatically designating the target axis is performed. You may want to do it. For example, in the case of a system having a diagnostic function for diagnosing the battery exhaustion of the encoder 15, the axis designation processing unit 19 automatically designates the axis corresponding to the one whose battery exhaustion is detected by the diagnostic function as the target axis. (Setting) may be performed.

2 ... Robot, 3, 32 ... Controller, 16 ... Display unit, 13 ... Motor, 15 ... Encoder, 19 ... Axis designation processing unit, 20 ... Display processing unit, 21 ... Execution processing unit, 33 ... Notification processing unit, J1 to J6 ... Axis.

Claims (6)

The operator drives the target axis in a state where the operator rotates the target axis so that the angle of the target axis, which is the target of origin extraction among the plurality of axes of the robot, becomes a predetermined reference angle. It is a method for calibrating the relationship between the detection value of the encoder that detects the rotation angle of the motor and the actual angle of the target axis.
The axis designation processing procedure for designating the target axis and
When the axis not specified in the axis designation processing procedure among the plurality of axes is used as the non-target axis, the angle of the target axis becomes the reference angle and the angle of the non-target axis becomes the detection value of the encoder. A display processing procedure for displaying on the display device a posture display indicating the posture of the robot such that the current angle is detected based on the above.
An execution processing procedure for executing the origin setting according to an operation for execution by the worker, and
How to get the origin of the robot including. In the display processing procedure,
The method for determining the origin of a robot according to claim 1, wherein the posture display is such that the appearance of the robot is schematically represented. In the display processing procedure,
The display device is designed to display the angles related to each of the plurality of axes.
The method for originating a robot according to claim 1 or 2, wherein the display mode of the angle of the target axis and the display mode of the angle of the non-target axis are different from each other. In the display processing procedure,
The method for determining the origin of a robot according to any one of claims 1 to 3, wherein the attitude indicator is updated intermittently or continuously. Further, when the reference angle corresponding to the target axis is an angle when the arm of the robot comes into contact with a predetermined object, the target axis is rotated at the time of origin setting based on the reference angle. The direction to be rotated is obtained, and the direction in which the target axis is currently rotated is obtained based on the detection value of the encoder, and when the respective directions do not match, the direction in which the target axis is rotated is incorrect. The method for determining the origin of a robot according to any one of claims 1 to 4, which includes a notification processing procedure for notifying the operator. A robot having a plurality of axes, a controller for controlling the operation of the robot, and a display device for displaying the robot, and the target which is the target of origin determination among the plurality of axes. The detection value of the encoder that detects the rotation angle of the motor that drives the target shaft while the operator rotates the target shaft so that the angle of the shaft becomes a predetermined reference angle, and the actual detection value of the target shaft. It is a system for setting the origin to calibrate the relationship with the angle.
The controller
The axis designation processing unit that specifies the target axis and
When the axis not specified in the axis designation process among the plurality of axes is set as the non-target axis, the angle of the target axis becomes the reference angle and the angle of the non-target axis becomes the detection value of the encoder. A display processing unit that causes the display device to display an attitude display indicating the attitude of the robot so that the current angle is detected based on the present angle.
An execution processing unit that executes the origin setting according to an operation for execution by the worker, and an execution processing unit.
A robot origin system equipped with.

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