JP7260105B1 - Teaching system and teaching method - Google Patents

Abstract

An object of the present invention is to enable direct teaching to be performed simply and efficiently. An end effector (42) is attached via a pressing force adjusting mechanism (43) to the tip of an arm of a robot. The pressing force adjusting mechanism 43 can adjust the pressing force when pressing the workpiece by the end effector 42 so as to be constant. The relative distance between the tip and end effector 42 is changed. The setting support device 61 connected to the robot controller 51 acquires encoder information indicating the angle of each joint from the encoder 26 of each joint when the user performs a position acquisition operation, and performs the position acquisition operation. Assuming that the pressing force adjusting mechanism is in the longest state when is performed, the movement of the robot is taught based on the information on the length of the pressing force adjusting mechanism 43 in the longest state and the encoder information. Set control points for [Selection diagram] Fig. 2

Description

The present invention relates to teaching systems and teaching methods.

Conventionally, when teaching an industrial robot such as an articulated robot, a method of creating an operation program using an operation terminal such as a teaching pendant has been employed. However, with such a method, it is not possible to intuitively give instructions to the robot, and there is a problem that it takes a lot of time for an inexperienced operator to achieve a desired movement. In recent years, a technique (so-called direct teaching) in which an operator directly touches a robot to teach a robot has been proposed in order to improve the efficiency of teaching (see, for example, Patent Document 1).

JP 2017-74669 A

Here, it is relatively easy to teach the movement by direct teaching, for example, for a simple movement such as conveyance of a work. On the other hand, if you try to teach the movement of cutting and polishing the workpiece by direct teaching, you can achieve uniform machining with reduced unevenness in cutting, etc., and the pressing force on the machining surface of the workpiece will be constant. In this way, it is necessary to move the end effector along the machining surface while pressing the end effector, which makes direct teaching extremely difficult. It is not preferable in terms of promoting automation by robots that direct teaching also requires user skill. Moreover, even a user with a high level of skill may need to concentrate and re-do the teaching due to the need for detailed handling as described above. This is not preferable in terms of improving work efficiency. In this way, there is still room for improvement in the configuration and specific methods related to the teaching in order to enable direct teaching to be performed easily and efficiently.

It should be noted that the above-mentioned problems related to direct teaching are not problems that occur only in processing operations such as shaving and polishing. This may also occur when direct teaching is used for other work requiring movement of the end effector.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems exemplified above, and a main object of the present invention is to enable direct teaching to be performed simply and efficiently.

Means for solving the above problems will be described below.

First means. An arm, an end effector disposed on the tip side of the arm, and a pressing force adjustment interposed between the arm and the end effector, which can adjust the pressing force of the end effector against the workpiece to a predetermined value. mechanism, wherein the pressing force adjusting mechanism expands and contracts as the pressing force is adjusted, thereby changing the relative distance between the tip of the arm and the end effector, and A robot capable of teaching a predetermined movement by direct teaching to move the end effector along the predetermined portion while maintaining the state in which the end effector is in contact with the predetermined portion of the planar or linear shape in A teaching system,
The direct teaching is performed under the condition that the pressing force adjustment mechanism is activated,
When the user performs an operation to designate an operation position while the end effector is in contact with the predetermined portion, information on the current operation position is acquired, and the predetermined operation position is obtained based on the acquired information on the current operation position. A setting unit for setting teaching data for teaching the movement of
The setting unit determines whether the pressing force adjusting mechanism is in a predetermined state or in a contracted state more than the predetermined state when the information on the operating position is acquired. Even if there is, it is assumed that the pressing force adjustment mechanism is in a standby state in which adjustment of the pressing force due to contact between the work and the end effector does not occur, or contraction of the pressing force adjustment mechanism is taken into account. without setting the teaching data.

According to the configuration shown in the first means, even if the pressing force adjustment mechanism contracts due to the adjustment of the pressing force, the teaching data is set as if it were not contracted. When the robot is operated according to the set teaching data (during automatic operation), there will be a gap between the position of the hand (for example, the end effector) assumed in the control and the actual position of the hand. . By deliberately creating such a gap, when the hand is moved toward the assumed pressure position assumed in the control by automatic operation, the actual position of the hand is made to precede the assumed position of the hand. be able to. As a result, during automatic operation, while the robot is changing its posture, that is, before it reaches the assumed pressing position, the hand touches the workpiece, and the force (advance force) that moves the hand toward the assumed pressing position ) will change to the pressing force that presses the workpiece. At this time, for example, when the actual pressing force exceeds the predetermined pressing force, the excessive pressing force is absorbed by the pressing force adjusting mechanism, and the workpiece is appropriately pressed. It should be noted that creating the above-mentioned gap is advantageous in that it is difficult to cause the inconvenience that a gap is generated between the end effector and the work during automatic operation, that is, that the two do not come into contact with each other. This is preferable in terms of preventing the pressing force adjusting function from becoming ineffective.

Further, according to the configuration shown in the first means, the relative distance between the tip of the arm and the end effector is changed by expanding and contracting the pressing force adjusting mechanism. In other words, even if the end effector is pushed further after coming into contact with the workpiece during direct teaching, the actual pushing force during automatic operation will not be affected, at least within the range where the relative distance is changed (decreased) by the pushing force adjustment mechanism. It is possible to avoid the phenomenon that the pressure increases in proportion to the excessive pressing during direct teaching. In other words, since the operator does not need to pinpoint the degree of pressing so as to obtain a desired pressing force, it is possible to shorten the time from confirmation of contact to designation operation. For the above reasons, teaching can be performed easily and efficiently. This is preferable in lowering the teaching proficiency requirements and facilitating robotic automation.

Second means. An arm, an end effector disposed on the tip side of the arm, and a pressing force adjustment interposed between the arm and the end effector, which can adjust the pressing force of the end effector against the workpiece to a predetermined value. mechanism, wherein the pressing force adjusting mechanism expands and contracts as the pressing force is adjusted, thereby changing the relative distance between the tip of the arm and the end effector, and A teaching method for teaching, by direct teaching, a predetermined movement to move the end effector along the predetermined portion while maintaining a state in which the end effector is in contact with a predetermined planar or linear portion in hand,
The end effector is brought into contact with the predetermined portion under the condition that the pressing force adjustment mechanism is activated,
Acquiring information on a current operating position while the end effector is in contact with the predetermined portion;
Regardless of whether the pressing force adjusting mechanism is in a predetermined state or in a contracted state more than the predetermined state when the information on the operating position is acquired, the Assuming that the pressing force adjustment mechanism is in a standby state in which adjustment of the pressing force due to contact between the work and the end effector does not occur, or without considering the contraction of the pressing force adjustment mechanism, the predetermined Sets the teaching data for teaching the movement of the

According to the method shown in the second means, direct teaching can be performed easily and efficiently.

Schematic diagram showing a robot in one embodiment. FIG. 2 is a block diagram showing the electrical configuration of the robot system; Schematic diagram showing how the pressing force is adjusted. Schematic diagram showing a teaching system. Schematic which shows the structure which concerns on the partial control of a stroke. Schematic diagram showing the flow of teaching. Schematic diagram showing contrast. Schematic diagram showing the flow of control point setting. Schematic diagram showing the relationship between the state of the pressing force adjustment mechanism and the control point.

An embodiment embodied in a robot system used in a factory polishing process or the like will be described below with reference to the drawings.

As shown in FIG. 1, the robot system 10 includes a robot 11 that is a vertically articulated (six-axis) industrial robot, and a controller 51 (see FIG. 2) that controls the robot 11 . The robot 11 has a robot body 21 composed of a base 22 fixed to the floor or the like and an arm 23 attached to the base 22 . The arm 23 is formed by connecting a plurality of movable parts, and is provided with a motor 25 for driving the movable parts for each joint and an encoder 26 for detecting the rotation angle of each joint (shaft) (Fig. 2).

A distal end unit 41 formed by unitizing an end effector 42 and a pressing force adjusting mechanism 43 is arranged at the distal end portion 24 of the arm 23 . 24 is attached. The end effector 42 includes a disc for grinding and a motor as a disc drive unit, and the disc is rotatable around an axis CL (specifically, the axis of the sixth axis) extending in the same direction as the distal end portion 24 of the arm 23. It has become. This motor is connected to a controller 51 (specifically, a unit controller 53), and the controller 51 controls the rotational speed and the like.

In the polishing process to which the robot system 10 is applied, a work W (for example, a helmet) is set on a table TB attached to the robot 11, and the end effector 42 is pressed against the work W while the end effector 42 is rotated. Thus, the surface of the work W (the curved outer peripheral portion) is polished. In this embodiment, the surface of the workpiece W corresponds to the "predetermined portion".

As shown in FIG. 2, the controller 51 is connected to a setting support device 61 such as a personal computer or a teaching pendant. The control unit 62 of the setting assistance device 61 is installed with an application that assists the user in setting the movement of the robot 11 (including offline teaching and direct teaching). Operation instructions set by teaching are stored in the memory 63 and sent to the controller 51 when the robot 11 is to be automatically operated. This operation instruction includes information indicating control points for the robot 11 (corresponding to "teaching data").

The controller 51 receives the operation instruction from the setting support device 61 , reads an operation program corresponding to the operation instruction from the program storage unit, and specifies the operation target positions of the movable parts that constitute the arm 23 . A target trajectory that smoothly connects the motion target position specified from the motion instruction and the current position of each movable part is generated, and interpolation positions, which are positions obtained by subdividing the target trajectory, are obtained by a servo amplifier built into the robot main body 21 (illustrated). abbreviated). A motor 25 and an encoder 26 are connected to the servo amplifier, and drive control of the motor 25 for each joint is performed based on an instruction from a controller 51 (more specifically, a robot controller 52) and a rotation angle detected by the encoder 26. etc.

Here, when polishing the surface of the work W, the degree of scraping of the work W varies depending on the magnitude of the force (pressing force) with which the end effector 42 is pressed against the work W. FIG. In other words, in order to suppress unevenness in polishing, it is necessary to perform polishing with the pressing force kept as constant as possible. In the robot 11 shown in this embodiment, the pressing force adjustment mechanism 43 is interposed between the arm 23 and the end effector 42 in order to suppress such changes in the pressing force (to make the pressing force constant). there is Here, with reference to FIG. 3, the pressing force adjusting mechanism 43 will be additionally described.

The pressing force adjusting mechanism 43 is a solenoid type actuator, and has a case 44 and a plunger 45 held by the case 44 so as to be movable in the same direction as the axis CL. The end effector 42 is fixed to one end of the plunger 45, and the end effector 42 follows the plunger 45 and displaces in the direction of the axis CL. The pressing force adjusting mechanism 43 is connected to the unit controller 53 , and the unit controller 53 monitors the pressing force of the work W by the end effector 42 . In the unit controller 53, the pressing force desired by the user can be arbitrarily set. By comparing the reference value set by the user with the monitoring result of the pressing force, the actual measurement value of the pressing force = the reference value The power supplied to the pressing force adjusting mechanism 43 is changed so that

In the example shown in FIG. 3A, the actual value of the pressing force is 21N, which exceeds the reference value of 20N. This phenomenon occurs because the arm 23 is too close to the workpiece W, for example. In this case, the unit controller 53 reduces the output of the pressing force adjustment mechanism 43 by reducing the power supply. From this, the measured value of the pressing force drops to 20 N, and the measured value matches the reference value. The amount of protrusion of the plunger 45 (remaining stroke on the compression side) decreases with such a change in the pressing force (S1→S2).

On the other hand, in the example shown in FIG. 3B, the actual measurement value of the pressing force is 19N, which is lower than the reference value of 20N. This phenomenon occurs because the arm 23 is too far from the workpiece W, for example. In this case, the unit controller 53 increases the output of the pressing force adjustment mechanism 43 by increasing the power supply. As a result, the actual measurement value of the pressing force increases to 20 N, and the actual measurement value and the reference value match. The amount of protrusion of the plunger 45 (remaining stroke on the compression side) increases (S1→S3) as the pressing force changes.

The specific configuration for moving the plunger 45 in both directions is arbitrary. While moving in one direction by magnetic force, it may be configured to move in other directions by biasing force such as a spring. , and a drive unit (for example, a second solenoid) that moves in another direction by magnetic force may be used together.

Next, a method for teaching the robot 11 how to polish the work W by the robot 11 equipped with the pressing force adjusting mechanism 43 will be described. In this embodiment, as the method, direct teaching is embodied in which the user directly moves the robot by hand to designate control points.

As shown in FIG. 4, the robot 11 is installed within a safety fence G surrounding the processing area of the factory in consideration of safety. In this embodiment, a leader-follower relationship is established between the robots 11 and 111 by linking the robot 11 and a similar robot 111 that is a smaller version of the robot 11 . Specifically, the robot 111 is assumed to be a leader robot (hereinafter also referred to as a leader robot 111), and the robot 11 is assumed to be a follower robot (hereinafter also referred to as a follower robot 11) that operates in the same posture as the leader robot 111. there is

Like the follower robot 11, the leader robot 111 is of a vertically articulated type (6 axes), and has a robot main body consisting of a base 122 placed on a workbench or the like and an arm 123 attached to the base 122. 121. The arm 123 is formed by connecting a plurality of movable parts, and is provided with a motor for driving the movable parts for each joint and an encoder for detecting the rotation angle of each joint (shaft). The leader robot 111 is connected to the controller 51 , and the follower robot 11 , leader robot 111 , controller 51 and setting support device 61 constitute a “teaching system”. The motion information of the leader robot 111 and the motion information of the follower robot 11 are transmitted to the setting support device 61 through the controller 51 .

When the user E touches the leader robot 111 to change the posture of the leader robot 111 , the rotation angles of the joints of the leader robot 111 are input to the setting support device 61 via the controller 51 . The setting support device 61 determines the rotation angles of the joints of the follower robot 11 according to the rotation angles of the joints of the leader robot 111 , and transmits a posture change command of the follower robot 11 to the controller 51 . The controller 51 changes the posture of the follower robot 11 based on the command. As a result, the change in posture of the leader robot 111 is reflected in the follower robot 11 .

The arm 123 of the leader robot 111 (specifically, the portion near the tip 124) is provided with a move button 128 and a position capture button 129, which are operation units operated by the user. The posture change of the leader robot 111 is restricted during direct teaching, and the posture of the leader robot 111 can be changed only while the movement button 128 is being pressed.

When the user operates position capture button 129 , the capture command is transmitted to setting support device 61 . The setting support device 61 that has received this fetch command acquires encoder information indicating the rotation angle of each axis from the encoder 26 of the follower robot 11 or the like, and information indicating the control point specified from the encoder information (hand position information) is stored in the memory 63 of the setting support device 61 as teaching data.

The user can teach the movement of the arm 123 of the follower robot 11 by repeating the movement operation and position acquisition operation of the arm 123 of the leader robot 111 . Then, the control unit 62 of the setting support device 61 specifies each control point from the teaching data recorded in time series by the memory 63, and drives and controls the arm 23 so that the hand passes through these control points. reproduce the behavior.

In this embodiment, the pressing force adjustment mechanism 43 is turned ON not only during automatic operation but also during direct teaching. Then, the pressing force is adjusted to the reference value set by the user at the start of direct teaching or the like. This reference value is set (for example, 10 N) to be lower than the reference value (for example, 20 N) for polishing by automatic operation. This is a device that makes it easier for the stroke change associated with the pressing force adjustment to occur when the end effector 42 is pressed against the work W during direct teaching.

However, during direct teaching, the function of the pressing force adjusting mechanism 43 is partially restricted. Specifically, the stroke range of the plunger 45 is narrowed when the pressing force is adjusted. The basic state of the pressing force adjustment mechanism 43 shown in the present embodiment is a state in which the amount of protrusion of the plunger 45 is maximum (longest state). This state is maintained. When direct teaching is started, the stroke amount is regulated so that the maximum amount of protrusion of the plunger 45 is smaller than that in the basic state. Here, with reference to FIG. 5, the configuration related to the regulation will be described.

A flange 49 is formed on the plunger 45 so as to protrude from the shaft portion of the plunger 45 . A stopper 48 is provided in the case 44 to contact the flange 49 from the front side (lower side) in the pressing direction. When the flange 49 comes into contact with the stopper 48, further projection becomes impossible. That is, the stopper 48 defines the maximum amount of projection of the plunger 45 (see SMAX).

A slit penetrating inside and outside is formed in the side surface of the case 44, and a plate-shaped restricting member 46 can be inserted through this slit. By pushing the regulating member 46 into the predetermined mounting position, the regulating member 46 is sandwiched between the stopper 48 and the locking portion 47 , and the locking portion 47 is caught to prevent the regulating member 46 from coming off the case 44 .

A notch into which the shaft of the plunger 45 is inserted is formed in the regulating member 46. By pushing the regulating member 46 into the predetermined mounting position, the shaft is inserted into the notch. The notch has a size that prevents the flange 49 from passing therethrough. It is necessary to secure a clearance in which the regulation member 46 can be inserted between .

When the restricting member 46 is attached, the restricting member 46 is interposed between the stopper 48 and the flange 49 . Further projection of the plunger 45 is avoided by the flange 49 coming into contact with the restricting member 46 from the front side in the pressing direction. That is, the maximum protrusion amount of the plunger 45 is regulated by the regulating member 46 so as to be smaller than that in the basic state (SMAX→Smax). More specifically, the restricted section and the permissible section during the full stroke are compared, and a difference is generated such that the restricted section is smaller than the permissible section. This is a device for suppressing deterioration of the original function of the pressing force adjustment mechanism 43 . Next, the flow of direct teaching in this embodiment will be described with reference to FIG.

When direct teaching is performed, the posture of the leader robot 111 is changed by pushing and pulling the leader robot 111 while the movement button 128 provided on the leader robot 111 is being pressed. The attitude of the follower robot 11 is also changed so as to follow such a change in the attitude of the leader robot 111 . There is no object corresponding to the work W near the leader robot 111 , and the work W is arranged near the follower robot 11 . Therefore, the user operates the reader robot 111 to bring the end effector 42 closer to the work W while visually confirming the end effector 42 of the reader robot 111 and the work W. FIG.

In the example shown in FIGS. 6A to 6B, the end effector 42 of the follower robot 11 is in contact with the workpiece W as a result of changing the posture of the leader robot 111 . As shown in FIG. 6(b)→FIG. 6(c), by continuing to change the posture of the leader robot 111, the end effector 42 is strongly pressed against the workpiece W, and the pressing force is the reference value. Over 10N. At this time, the pressing force is adjusted by the pressing force adjustment mechanism 43 . This adjustment reduces the amount of protrusion of the plunger 45 and shortens the overall length of the pressing force adjustment mechanism 43 .

In the example shown in FIG. 6, the position capture button 129 is operated after the end effector 42 contacts the workpiece W and continues to change its posture. At this point, the teaching data is set. After that, the operation of the position capture button 129 is repeated while moving the end effector 42 along the surface of the work W to change its position. In the example shown in FIG. 6(d), the position capture button 129 is operated at a different position from the example shown in FIG. 6(c). The amount of protrusion is different (see S4 and S5). Although it is difficult to bring the end effector 42 and the work W into contact with each other, the teaching operation is simplified by turning on the pressing force adjustment mechanism 43 and allowing a certain degree of error.

It is technically significant to turn on the pressing force adjusting mechanism 43 not only during automatic operation but also during direct teaching. However, in such a configuration, it is necessary to pay attention to the following points regarding setting of teaching data by teaching. The points to be noted (issues) will be described below with reference to the comparison in FIG.

In the comparison shown in FIG. 7, the pressing force adjusting mechanism 43 is in the shortest state during direct teaching. In this shortest state, the distance from the connection point EP between the tip portion 24 of the arm 23 and the tip unit 41 to the tip of the follower robot 11X (the tool center point APX of the end effector 42) is the shortest (full length L1). That is, the tool center point APX is located at a position offset from the connection point EP in the direction of the axis CL by the same distance as the overall length L1. Here, the control unit 62 of the setting support device 61 can specify the tool center point APX by considering the encoder information of each axis and the total length of the pressing force adjusting mechanism 43 . If information indicating the position of the tool center point APX is stored as teaching data (control point), the control point CPX when polishing the work W by automatic operation becomes a point on the surface of the work W, and this control The arm 23 operates so that the tool center point APX of the end effector 42 coincides with the point CPX. That is, the end effector 42 comes into contact with the workpiece W in a state (basic state) in which the adjustment margin of the pressing force adjusting mechanism 43 is left to the maximum.

With respect to such a contact mode, if the trajectory of the arm 23 deviates toward the work W or the set position of the work W deviates toward the robot 11X, the pressing force adjustment function can be properly adjusted. It is advantageous because it can be demonstrated. On the other hand, if the trajectory of the arm 23 deviates away from the work W or the set position of the work W deviates away from the robot 11X, it is difficult to further increase the stroke, and the pressing force There is a concern that the adjustment function will not work well. When the end effector 42 is moved along the surface of the workpiece W, the movement distance becomes longer to some extent, and if the above event occurs in the process, polishing may be partially insufficient. This is not preferable in terms of improving processing quality. The present embodiment is devised in consideration of such circumstances. Hereinafter, a configuration related to setting of teaching data in this embodiment will be described with reference to FIGS. 8 and 9. FIG.

As shown in FIG. 8 , when setting teaching data, first, the control unit 62 of the setting support device 61 acquires encoder information from each encoder 26 of the follower robot 11 . On the other hand, information indicating the state of the pressing force adjusting mechanism 43 (control information and stroke information) is not acquired from the pressing force adjusting mechanism 43 . The control unit 62 treats the pressing force adjusting mechanism 43 as being in the basic state (maximum state), and determines the acquired encoder information and the maximum total length LMAX of the pressing force adjusting mechanism 43 in the pre-stored basic state. The control point CP is set based on the indicated information, specifically the distance from the connection point EP to the tool center point AP.

For example, as shown in FIG. 9(a), when the pressing force adjustment mechanism 43 is in a state of being compressed to the total length L1, the control point CP1 is determined based on the maximum total length LMAX instead of the total length L1. is set. For this reason, the set control point CP1 is shifted forward from the surface of the work W in the pressing direction. When performing polishing by automatic operation, the arm 23 is operated so that the control point CP1 and the tool center point AP coincide, thereby suppressing the end effector 42 from coming out of contact with the workpiece W. .

In the example shown in FIG. 9(b), the pressing force adjusting mechanism 43 is in a compressed state as in FIG. 9(a), but the total length L2 is different from the total length L1. Also in this case, the control point CP2 is set based on the maximum total length LMAX instead of the total length L2. For this reason, the set control point CP2 is shifted forward from the surface of the work W in the pressing direction. When performing polishing by automatic operation, the arm 23 is operated so that the control point CP2 and the tool center point AP coincide, thereby suppressing the end effector 42 from coming out of contact with the workpiece W. .

FIG. 9(c) schematically shows an area in which control points are set. The control point set by the teaching described above falls within a region between the surface SL of the workpiece W and a virtual plane FL offset inward from the surface SL by the stroke amount of the pressing force adjusting mechanism 43 in the regulated state. Become. Therefore, the target motion trajectory connecting the control points is also inside the surface SL of the work W, and the end effector 42 moving along this target motion trajectory is maintained in contact with the work W, and the pressing force is Since it is within the range of the adjustment effect of the adjusting mechanism 43, the function of keeping the pressing force of the pressing force adjusting mechanism 43 constant can be exhibited favorably.

According to the embodiment detailed above, the following excellent effects can be expected.

Even if the pressing force adjusting mechanism 43 is contracted by adjusting the pressing force, the teaching data (control point) is set as if it were not contracted. When the robot 11 is operated according to the set teaching data (during automatic operation), there is a gap between the position of the end effector 42 assumed for control and the actual position of the end effector 42. . By deliberately creating such a gap, when the end effector 42 is moved toward the assumed pressing position assumed in the control by automatic operation, the position of the actual end effector 42 is changed to the assumed end effector 42 can precede the position of As a result, during automatic operation, the end effector 42 hits the workpiece W while the posture of the robot 11 is being changed, that is, before reaching the assumed pressing position, and the end effector 42 moves toward the assumed pressing position. The force (advance force) to be changed to the pressing force that presses the work W. As shown in FIG. At this time, for example, when the actual pressing force exceeds a reference value, the excess pressing force is absorbed by the pressing force adjusting mechanism 43, and the workpiece W is appropriately pressed. It should be noted that the creation of the gap is advantageous in that it is difficult to cause the inconvenience of a gap between the end effector 42 and the work W during automatic operation, that is, the two do not come into contact with each other. This is preferable in terms of preventing the pressing force adjusting function from becoming ineffective.

In addition, the relative distance between the distal end portion 24 of the arm 23 and the end effector 42 is changed by expanding and contracting the pressing force adjusting mechanism 43 . In other words, even if the end effector 42 abuts on the workpiece W and then pushes it further, within the range in which the relative distance is changed (decreased) by the pressing force adjusting mechanism 43, the pressing force at the time of actual polishing is reduced. It is possible to avoid the phenomenon that the height is increased by the pushing amount during direct teaching. In other words, the user does not need to pinpoint the degree of pressing so as to obtain a desired pressing force, so the time from contact confirmation to designation operation can be shortened. For the above reasons, teaching can be performed easily and efficiently. This is preferable in lowering the teaching proficiency requirements and facilitating robotic automation.

In the present embodiment, by setting the teaching data based on the state (standby state) in which the relative distance is maximum, when the robot 11 operates based on the teaching data, the end effector 42 and the work W are not in contact with each other. It is possible to more preferably reduce the chances of causing inconveniences such as the occurrence of gaps.

The stroke range in which the pressing force adjusting mechanism 43 can extend and retract during direct teaching is included in the stroke range in which the pressing force adjusting mechanism 43 can extend and retract during automatic operation, so that the stroke range can be taken into account in direct teaching. It is possible to suitably suppress the occurrence of re-teaching, such as being out of the support by the pressing force adjustment mechanism during automatic operation in spite of being designated as .

If the surface of the work W is slightly curved or uneven, the distance between the work W and the end effector 42 will be larger than expected. In such a case, the difficulty in providing support on the extension side is a factor in not being able to exhibit the function of keeping the pressing force constant. In this regard, as shown in the present embodiment, if the pressing force adjustment mechanism 43 is configured to be used in the range from the shortest state to the intermediate state during direct teaching, that is, if it is configured to be slightly contracted, polishing can be performed. When it is executed, it is possible to secure a certain amount of allowance for the support on the extension side, and it is possible to improve the ability to follow the curve or the like.

As shown in the present embodiment, in the configuration in which the follower robot 11 is operated so as to follow the leader robot 111, the user moves away from the follower robot 11 by operating the leader robot 111 at hand while looking at the follower robot 11. Remote direct teaching is possible at the same position. This is preferable in terms of enabling teaching by direct teaching even for robots that are difficult for the user to touch and move. However, with such a method, it is difficult to finely adjust the position of the end effector 42 (orientation of the follower robot 11) by operating the leader robot 111 at hand while visually observing the follower robot 11 at a distance. It is stressful even for a user with a high skill level that such detailed work is essential. Here, if a configuration is adopted in which a certain amount of margin is provided in setting the control points as shown in the present embodiment, the inconvenience of teaching from a distance using the reader robot 111 can be resolved favorably.

The ideal pressing force may differ between direct teaching and automatic operation. Therefore, by making it possible to set the standard pressing force (reference value) separately for when direct teaching is performed and when automatic operation is performed, the pressing force during teaching may become excessively large. , can be suppressed from becoming excessively small.

Setting the pressing force adjusting mechanism 43 in the intermediate state during direct teaching as shown in the present embodiment has the following merits. That is, since the operating position is taught in a slightly compressed state, there is room for the pressing force adjustment mechanism 43 to extend even when the pressing force is reduced. As a result, even if the end effector 42 is likely to be lifted from the surface of the work W due to deviation of the installation position of the work W, individual differences of the work W, or the like, contact with the surface can be favorably ensured.

<Modification>
It should be noted that the present invention is not limited to the contents described in the above-described embodiment, and may be implemented as follows, for example. Incidentally, each of the following configurations may be applied individually to the above embodiment, or may be applied to the above embodiment by combining a part or all of them.

・In the above-described embodiment, it is assumed that the pressing force adjustment mechanism 43 is in the maximum stretched state (basic state) regardless of the stretched state, and based on the information on the maximum stretched state and the encoder information of the follower robot 11, Although the control point is set, the control point may be set based on the encoder information of the follower robot 11 without considering the state of the pressing force adjusting mechanism. In such a configuration, the drive control is not performed so that the tool center point AP coincides with the control point, but the distal end portion 24 (the connection point EP) of the arm 23 is made so as to coincide with the control point. It is preferable to adopt a configuration in which drive control is performed by In the above embodiment, information indicating the state of the pressing force adjusting mechanism 43 from the pressing force adjusting mechanism 43 is not input to the setting support device 61 during teaching. On the other hand, it is also possible to configure such that the same information is not referred to when setting the control point. For example, the information indicating the state of the pressing force adjusting mechanism 43 may be configured to be used for notification, which will be described later.

In the above embodiment, when restricting the stroke of the pressing force adjusting mechanism 43 to be short during direct teaching, it is assumed that the user manually attaches the restricting member 46 to the pressing force adjusting mechanism 43. By changing this, when the direct teaching start operation is performed by the setting support device 61 or the like, the locking device or the like provided in the pressing force adjusting mechanism is operated to automatically perform the above regulation. It is also possible to

・When using the regulating member 46 to regulate the stroke of the pressing force adjusting mechanism 43 to be short, the regulated section in the full stroke is compared with the allowable section, and the difference is made so that the regulated section is smaller than the allowable section. is provided, but is not limited to this. The restricted section and the permissible section may have the same length, or a difference may be provided so that the restricted section is longer than the permissible section.

- In the above embodiment, the direct teaching of the follower robot 11 is performed using the leader robot 111, but the present invention is not limited to this. It is also possible to employ a configuration in which direct teaching is performed by directly moving the robot 11 by hand.

- Although the pressing force adjusting mechanism 43 shown in the above embodiment is electrically operated, it may be changed to a hydraulic or pneumatic type as long as the pressing force can be adjusted.

・During direct teaching, the setting support device 61 grasps the state of the pressing force adjustment mechanism 43, and the display of the setting support device 61 indicates what state (stretched state) the pressing force adjustment mechanism 43 is in. It is good also as a structure which alert|reports by. For example, when the remaining adjustment margin of the pressing force adjustment mechanism 43 becomes smaller than the threshold value or becomes 0, it may be configured to notify that fact. In addition, considering that the user performs the work while watching the robot 11 during direct teaching, the configuration may be such that the notification is given by lighting a lamp or the like provided on the robot 11 in a predetermined display mode. If so, it is possible to reduce the chances that the user will miss the notification.

In the above-described embodiment, the configuration in which the reference pressing force (reference value) to be adjusted by the pressing force adjustment mechanism 43 is different between when teaching is performed and when automatic operation is performed has been exemplified. It is not intended to deny a configuration in which the reference value is the same in the case of implementation and in the case of implementation of automatic operation.

- Stroke regulation at the time of direct teaching shown in the above embodiment is not an essential configuration, and a configuration in which the stroke regulation is not performed may be adopted.

- In the above embodiment, the robot 11 is used to polish the workpiece W. However, it is preferable to move the end effector along the surface of the workpiece while maintaining a constant pressing force. The robot 11 can also be applied to work other than polishing if it can be performed. For example, the robot 11 may be used to grind the workpiece. In addition, the object to be polished or ground is not necessarily limited to a planar portion. It is also possible to subject the flat portion to polishing or grinding. Also, the robot 11 may be engaged in the assembly process. For example, when assembling a resin member such as a weatherstrip or trim into a groove, the resin member is pressed against the groove with a constant pressure while shifting the pressing position in the longitudinal direction of the groove. The robot 11 may be applied to such work.

<Invention group extracted from the above embodiment>
Hereinafter, the features of the group of inventions extracted from the above-described embodiments will be described while showing effects and the like as necessary. In the following description, for ease of understanding, configurations corresponding to the above-described embodiments are appropriately shown in parentheses or the like, but are not limited to the specific configurations shown in parentheses or the like.

Feature 1. an arm (arm 23), an end effector (end effector 42) disposed on the tip (tip 24) side of the arm, and an end effector interposed between the arm and the end effector, the above-mentioned end effector for the work (workpiece W). A pressing force adjusting mechanism (pressing force adjusting mechanism 43) capable of adjusting the pressing force of the end effector to be constant is provided. Applied to a robot (robot 11) configured to change the relative distance between the tip and the end effector, the end effector is brought into contact with a predetermined planar or linear portion (surface of the work W) of the work. A teaching system for a robot capable of teaching, by direct teaching, a predetermined movement to move the end effector along the predetermined portion while maintaining the state of the end effector,
The direct teaching is performed under the condition that the pressing force adjustment mechanism is activated,
Information on the current operating position (angle of each axis) is acquired when the user performs an operating position specifying operation (operating the position acquisition button 129) while the end effector is in contact with the predetermined portion. , a setting unit (for example, a setting support device 61) for setting teaching data (control points for tool center points, etc.) for teaching the predetermined motion based on the acquired information of the current motion position,
The setting unit determines whether the pressing force adjusting mechanism is in a predetermined state or in a contracted state more than the predetermined state when the information on the operating position is acquired. Even if there is, the pressing force adjusting mechanism is in a standby state (maximum state) in which the pressing force adjustment due to the contact between the work and the end effector does not occur, or the pressing force adjusting mechanism A teaching system for setting the teaching data without considering shrinkage.

According to the configuration shown in this feature, even if the pressing force adjustment mechanism contracts due to the adjustment of the pressing force, the teaching data is set as if it were not contracted. When the robot is operated according to the set teaching data (during automatic operation), there will be a gap between the position of the hand (for example, the end effector) assumed in the control and the actual position of the hand. . By deliberately creating such a gap, when the hand is moved toward the assumed pressure position assumed in the control by automatic operation, the actual position of the hand is made to precede the assumed position of the hand. be able to. As a result, during automatic operation, while the robot is changing its posture, that is, before it reaches the assumed pressing position, the hand touches the workpiece, and the force (advance force) that moves the hand toward the assumed pressing position ) will change to the pressing force that presses the workpiece. At this time, for example, when the actual pressing force exceeds the predetermined pressing force, the excessive pressing force is absorbed by the pressing force adjusting mechanism, and the workpiece is appropriately pressed. It should be noted that creating the above-mentioned gap is advantageous in that it is difficult to cause the inconvenience that a gap is generated between the end effector and the work during automatic operation, that is, that the two do not come into contact with each other. This is preferable in terms of preventing the pressing force adjusting function from becoming ineffective.

Further, according to the configuration shown in this feature, the relative distance between the tip of the arm and the end effector is changed by expanding and contracting the pressing force adjusting mechanism. In other words, even if the end effector is pushed further after coming into contact with the workpiece during direct teaching, the actual pushing force during automatic operation will not be affected, at least within the range where the relative distance is changed (decreased) by the pushing force adjustment mechanism. It is possible to avoid the phenomenon that the pressure increases in proportion to the excessive pressing during direct teaching. In other words, since the operator does not need to pinpoint the degree of pressing so as to obtain a desired pressing force, it is possible to shorten the time from confirmation of contact to designation operation. For the above reasons, teaching can be performed easily and efficiently. This is preferable in lowering the teaching proficiency requirements and facilitating robotic automation.

Note that "constant" includes not only the case where the pressing force is completely constant, but also variations in the pressing force within an allowable error range in machining, assembling, etc. of the workpiece. Incidentally, the description of the "pressing force adjusting mechanism" is described as "interposed between the arm and the end effector, and capable of adjusting the pressing force of the end effector against the workpiece to a predetermined value (predetermined pressing force)". good too.

Feature 2. The teaching system according to feature 1, wherein the standby state is a state in which the relative distance between the tip of the arm and the end effector is maximized.

By setting the teaching data based on the maximum relative distance (standby state), when the robot operates based on the teaching data, a gap may occur between the end effector and the workpiece. Opportunities can be reduced even better.

Feature 3. The teaching data indicates a control point (control point CP, etc.) as a target position of the hand of the robot,
Regardless of whether the pressing force adjusting mechanism is in a predetermined state or in a contracted state from the predetermined state when the information on each operating position is acquired, the pressing force adjustment mechanism Assuming that the pressure adjusting mechanism is in a standby state (maximum state) in which adjustment of the pressing force due to the contact between the work and the end effector does not occur, or without considering the contraction of the pressing force adjusting mechanism , by setting the teaching data, the control point is arranged on the front side in the pressing direction of the end effector with respect to the contact point (surface of the work W) with the end effector in the predetermined portion. Or the teaching system according to feature 2.

The teaching data is set so that the control point, which is the target position of the hand of the robot, is located on the front side in the pressing direction with respect to the contact point between the workpiece and the end effector. If the robot operates in accordance with this control point, the end effector will inevitably come into contact with the workpiece. With such a configuration, the technical idea shown in feature 1 can be suitably embodied.

Feature 4. Any of feature 1 to feature 3, wherein a stroke range in which the pressing force adjustment mechanism can extend and contract during the direct teaching is included in a stroke range in which the pressing force adjustment mechanism can extend and retract during automatic operation of the robot. A teaching system according to claim 1.

As shown in this feature, the stroke range in which the pressing force adjustment mechanism can extend and retract during direct teaching is included in the stroke range in which the pressing force adjustment mechanism can extend and retract during automatic operation. It is possible to suitably suppress the occurrence of re-teaching such as being out of the support by the pressing force adjustment mechanism during automatic operation even though the stroke range is specified in consideration of it.

Feature 5. The state of the pressing force adjustment mechanism includes a longest state in which the relative distance between the tip of the arm and the end effector is the longest, and a shortest state in which the relative distance between the tip of the arm and the end effector is the shortest. , and an intermediate state between the longest and shortest states,
Teaching according to any one of features 1 to 4, wherein during the direct teaching, the state of the pressing force adjustment mechanism can be regulated so as to transition between the shortest state and the intermediate state. system.

If the surface of the work is slightly curved or uneven, the distance between the work and the end effector will be larger than expected. In such a case, the difficulty in providing support on the extension side is a factor in not being able to exhibit the function of keeping the pressing force constant. In this regard, as shown in this feature, if the pressing force adjustment mechanism is configured to be used in the range from the shortest state to the intermediate state during direct teaching, that is, if it is configured to be slightly shortened, a predetermined operation is executed. In this case, a certain amount of allowance can be secured for the support on the extension side, and the followability to the bending or the like can be improved.

Note that the "intermediate state" may be a state close to the longest state, a state close to the shortest state, or a state in the middle between the longest state and the shortest state.

Feature 6. The robot is a target robot (follower robot 11) to be taught,
an operation robot (leader robot 111) configured to be able to change its posture by being directly touched and operated by a user;
a control unit (controller 51 and setting support device 61) that controls the posture of the target robot according to the posture of the operating robot;
The operating robot is deficient in the end effector and the pressing force adjustment mechanism of the target robot,
The teaching system according to any one of features 1 to 5, wherein the operation robot is provided with an operation unit (position acquisition button 129) for the specified operation.

According to the configuration shown in this feature, remote direct teaching can be performed at a position away from the target robot by operating the operating robot at hand while looking at the target robot. This is preferable in terms of enabling teaching by direct teaching even for robots that are difficult for the user to touch and move. However, with such a method, it is difficult to finely adjust the position of the end effector (orientation of the target robot) by operating the operating robot at hand while viewing the target robot in the distance. It is stressful even for a highly skilled worker to have to perform such detailed work. Here, by applying the technical idea shown in feature 1 and the like, it is possible to provide a certain amount of latitude in the amount of pressing that provides an appropriate pressing force. In this way, if the configuration allows for a certain degree of work variation, it is possible to solve the problem of teaching from a distance using an operation robot.

Feature 7. The teaching system according to any one of features 1 to 6, further comprising a notification unit (for example, a display screen or a lamp) that notifies a user of the expansion/contraction state of the pressing force adjustment mechanism during the direct teaching.

For example, if the end effector is strongly pressed against the workpiece and the operating position is specified with the pressure force adjustment mechanism greatly compressed, the adjustment range of the pressure force adjustment mechanism during automatic operation will be reduced on the compression side. will deviate significantly from This is not preferable in terms of absorbing individual differences in workpieces, deviations in installation positions of workpieces, and the like. Therefore, as shown in this feature, if the user is notified of the expansion/contraction state of the pressing force adjustment mechanism, it is possible to encourage consideration of the pressing force adjustment mechanism during teaching, thereby contributing to the elimination of the above concerns. In addition, in combination with feature 6, since it is assumed that the user will operate while looking at the target robot, it is preferable to provide notification to the target robot.

Feature 8. The pressing force adjustment mechanism adjusts the pressing force of the end effector against the workpiece to a predetermined pressing force,
A pressing force setting unit (unit controller 53) for setting the predetermined pressing force,
Any one of features 1 to 7, wherein the predetermined pressing force can be set to different values depending on whether the direct teaching is executed or the robot is automatically operated. The teaching system described in .

The ideal pressing force may differ between direct teaching and automatic operation. Therefore, by making it possible to set a predetermined reference pressing force (value) separately for when direct teaching is performed and when automatic operation is performed, the pressing force during teaching does not become excessively large. or excessively small.

For example, the predetermined pressing force when direct teaching is performed may be set lower than the predetermined pressing force when the robot is automatically operated.

Feature 9. The end effector according to any one of features 1 to 8, wherein the end effector is rotatably provided, and is pressed against the predetermined portion of the workpiece in a rotated state to grind or polish the predetermined portion. teaching system.

By applying the technical idea shown in feature 1 and the like, it is possible to suppress processing unevenness when a robot cuts or grinds a predetermined portion of a work, and to perform uniform processing. In order to exhibit such a function, when setting the teaching data of the operating position, the end effector should be in a state of being pressed against a predetermined portion by intentionally not considering the contraction of the pressing force control mechanism. can be done. In other words, it is possible to prevent the end effector from being lifted up from a predetermined portion, thereby preventing partial insufficient machining. Here, during teaching, it is only necessary to perform a specified operation with the end effector touching the work, and there is no need to adjust the amount of pushing force for normal operation of the pushing force adjusting mechanism, so work becomes easier and more efficient. can contribute to

Feature 10. Applied to the teaching system according to any one of features 1 to 9, the end effector is moved along the predetermined portion while maintaining the state in which the end effector is in contact with the predetermined portion. A teaching method for teaching a movement to cause by the direct teaching,
The end effector is brought into contact with the predetermined portion under the condition that the pressing force adjustment mechanism is activated,
A teaching method for specifying the operation position in the contact state.

During the direct teaching, even if the end effector is pressed too much when the instruction operation is performed with the end effector reaching a predetermined portion, the influence of the end effector on the teaching data can be suppressed. This is preferable in terms of simplification and efficiency of teaching work.

It should be noted that the description "specifying operation of the operating position is performed in the contact state" shown in this feature is changed to "the operating position is performed in the contact state and the pressing force adjustment mechanism is contracted." It is also possible to say "perform the designation operation of

Feature 11. an arm (arm 23), an end effector (end effector 42) disposed on the tip (tip 24) side of the arm, and an end effector interposed between the arm and the end effector, the above-mentioned end effector for the work (workpiece W). A pressing force adjusting mechanism (pressing force adjusting mechanism 43) capable of adjusting the pressing force of the end effector to be constant is provided. Applied to a robot (robot 11) configured to change the relative distance between the tip and the end effector, the end effector is brought into contact with a predetermined planar or linear portion (surface of the work W) of the work. A teaching method for teaching, by direct teaching, a predetermined movement to move the end effector along the predetermined portion while maintaining the state of the end effector,
The end effector is brought into contact with the predetermined portion under the condition that the pressing force adjustment mechanism is activated,
Acquiring information on a current operating position while the end effector is in contact with the predetermined portion;
Regardless of whether the pressing force adjusting mechanism is in a predetermined state or in a contracted state more than the predetermined state when the information on the operating position is acquired, the Assuming that the pressing force adjustment mechanism is in a standby state in which adjustment of the pressing force due to contact between the work and the end effector does not occur, or without considering the contraction of the pressing force adjustment mechanism, the predetermined A teaching system that sets teaching data for teaching the movement of the

During the direct teaching, even if the end effector is pressed too much when the instruction operation is performed with the end effector reaching a predetermined portion, the influence of the end effector on the teaching data can be suppressed. This is preferable in terms of simplification and efficiency of teaching work.

Feature 12. The state of the pressing force adjustment mechanism includes a longest state in which the relative distance between the tip of the arm and the end effector is the longest, and a shortest state in which the relative distance between the tip of the arm and the end effector is the shortest. , intermediate states between the longest and shortest states,
The teaching method according to feature 10 or feature 11, wherein the pressing force adjusting mechanism is placed in the intermediate state, and the direct teaching is performed while the transition from the intermediate state to the maximum state is regulated.

Setting the pressing force adjusting mechanism in the intermediate state as shown in this feature has the following merits. That is, since the operating position is taught in a slightly compressed state, there is room for the pressing force adjusting mechanism to expand even when the pressing force is reduced. As a result, even if the end effector is likely to be lifted from the predetermined portion due to deviation of the installation position of the work, individual differences in the work, or the like, it is possible to ensure proper contact with the predetermined portion.

The intermediate state may be set manually by the user, or the intermediate state may be automatically set when the teaching mode is set.

Feature 13. 13. The teaching method according to feature 12, wherein a stroke for transitioning from the longest state to the intermediate state is smaller than a stroke for transitioning from the intermediate state to the shortest state.

According to the configuration shown in this feature, it is possible to exhibit the effect shown in feature 10 and the like, while suppressing pressure on the permissible width of the pushing amount during teaching.

DESCRIPTION OF SYMBOLS 10... Robot system, 11... Robot (follower robot), 21... Robot main body, 23... Arm, 24... Tip part, 41... Tip unit, 42... End effector, 43... Pressure adjusting mechanism, 46... Regulating member, 51 Controller, 61: Teaching device, 62: Control section, 63: Memory, 111: Robot (leader robot), 129: Position acquisition button, CL: Axis, W: Work.

Claims (2)

an arm, an end effector disposed on the distal end side of the arm and constituting a hand of the robot, and a pressing force adjustment mechanism capable of adjusting the pressing force of the end effector against a workpiece to a predetermined value, wherein the pressing force The robot is configured such that the relative distance between the portion of the end effector that contacts the work and the tip of the arm changes as the adjustment mechanism expands and contracts along with the adjustment of the pressing force. A teaching system for a robot that can teach, by direct teaching, the movement of moving the end effector along the predetermined portion while maintaining the state in which the end effector is in contact with the predetermined portion of the planar or linear shape of and
The pressing force adjustment mechanism can be extended and contracted during direct teaching as well as during robot operation,
Information indicating the rotation angle of each axis of the robot when the user performs an acquisition operation in a situation where the pressing force adjustment mechanism contracts due to the contact between the work and the end effector. Acquired teaching data indicating control points for moving the hand during operation of the robot, information indicating the angle of rotation, and information indicating the adjustment of the pressing force when contraction has not occurred . A teaching system comprising a setting unit for setting based on information indicating the length of a pressing force adjusting mechanism. an arm, an end effector disposed on the distal end side of the arm and constituting a hand of the robot, and a pressing force adjustment mechanism capable of adjusting the pressing force of the end effector against a workpiece to a predetermined value, wherein the pressing force The robot is configured such that the relative distance between the portion of the end effector that contacts the work and the tip of the arm changes as the adjustment mechanism expands and contracts along with the adjustment of the pressing force. A teaching method for teaching by direct teaching the movement of moving the end effector along the predetermined portion while maintaining the state in which the end effector is in contact with the predetermined portion of the planar or linear shape in
The end effector is brought into contact with the predetermined portion under the condition that the pressing force adjustment mechanism can be expanded and contracted,
Acquiring information indicating a rotation angle of each axis of the robot while the end effector is in contact with the predetermined portion;
The teaching data indicating the control points for moving the hand during operation of the robot, the information indicating the rotation angle, and the adjustment of the pressing force when contraction associated with the adjustment of the pressing force is not occurring. A teaching method that is set based on information indicating the length of the mechanism.

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