JP6567101B2 - Teaching method, robot operating method, program, storage medium, teaching apparatus - Google Patents

Description

  The present invention relates to a teaching method that teaches operations so that a plurality of robots do not collide with each other while avoiding obstacles, and a teaching device used therefor. In particular, the present invention relates to a method and apparatus for generating and teaching an operation path that does not interfere with each other when a plurality of robots work simultaneously in a common work area.

  Automation such as assembly, transport, and application in factory production lines is performed using industrial robots. In many cases, these robots are arranged close to each other and work simultaneously in a common area in order to improve production capacity and save space. In such a case, conventionally, a teacher teaches by trial and error so that the robot does not interfere with each other in consideration of the route through which the robot passes and the timing for operating each robot.

  However, this method has a problem that as the number of robots and the number of operations increase, it becomes more difficult to find a trajectory without interference, and teaching work takes a lot of labor and time. In addition, every time there was a change in the arrangement of equipment and robots in the production line, the teaching work had to be reworked with a great deal of labor and time.

  Therefore, a technique for automatically generating a path in which a robot does not cause interference in a virtual space, instead of searching in real space by trial and error, has been studied. For example, route generation algorithms such as RRT (Rapidly-Expanding Random Tree) and PRM (Probabilistic Load Map Method) are known. If this technique is used, it is only necessary to specify the start point and end point of the robot operation, so the burden on the teacher in the teaching work can be reduced. In addition, even if there is a change in the arrangement of equipment and robots in the production line, the calculation is performed in the virtual space, so that a route that does not cause interference can be recalculated in a short time without occupying the production line.

  These techniques are techniques for generating a path that does not cause interference with an obstacle for a single robot. However, a method that does not cause interference even when a plurality of robots are used has been proposed.

  For example, Patent Document 1 discloses a technique for avoiding interference between robots by providing an interlock. Patent Document 1 describes an automatic interlock that automatically sets an interlock between a plurality of robots by editing an operation program of each of the plurality of robots in a system including a plurality of robots. It is a setting device. With respect to the area swept by the movement of the robot, it is determined whether or not there are overlapping portions between the plurality of robots. If there are overlapping portions, an interlock is provided at the entrance. The timing at which each robot passes through the interlock is adjusted so that the robots do not interfere with each other when passing through the overlapping portion.

  Non-Patent Document 1 discloses a technique for avoiding the occurrence of interference among a plurality of robots by adjusting the speed at the time of operation of the robot. In the trajectory generation of Non-Patent Document 1, the path from the start point to the end point of each robot is calculated assuming that no other robot exists, and then a graph is generated using the position of each robot on the path as a parameter. Then, on the generated graph, search for a combination of positions on the path of each robot without interference, and combine the first obtained path and a combination of positions on the path of each robot to adjust the operation speed. Operate and get trajectories that do not interfere with each other.

JP 2007-164417 A G. Sanchez and J.-C. Latombe, “On delaying collision checking in PRM planning: Application to multi-robot coordination” International Journal of Robotics Research, vol. 21, no. 1, pp. 5-26, 2002

  First, when a teacher teaches the area through which a plurality of robots pass in a real space and teaches them manually, the teacher is required to have high skills, and the teaching work requires a great deal of labor and time. It is.

  Further, in the methods disclosed in Patent Document 1 and Non-Patent Document 1, the trajectory of each robot is obtained in advance, and then the interference between the robots during operation is verified. Or trying to adjust the speed to prevent interference. However, since a trajectory created without considering the region through which another robot passes is used, there is a possibility that a solution for avoiding interference cannot be found only by adjusting the timing and speed. Even if a solution can be found, the operation speed of each robot is reduced or temporarily stopped in order to avoid interference, so that it takes a long time for the robot to complete all operations in the entire system. Tend to be.

  The present invention is a teaching method for teaching a plurality of robots arranged so as to have a common work area by using a computer, and includes a starting point and a via point of a reference part of each robot for the motion to be taught. A step of storing an operation command list including position information of end points by the computer, a step of storing information of positions and shapes of obstacles within the operation range of the plurality of robots, and the computer; However, based on the operation command list and the position and shape information of the obstacle, an additional via point for moving the reference portion from the start point to the end point while avoiding the obstacle is independently set for each robot. A teaching value generation step of generating and storing as a teaching value; and the computer operates the driving unit of each robot based on the teaching value. A robot passage area calculation step of calculating and storing a robot passage area, which is a set of trajectories drawn by points constituting each robot, in a virtual space for each robot; and An intersection detection step for detecting the presence or absence of intersections between the passing areas of the robots calculated in step (b), and when the computer detects an intersection in the intersection detection step, at least a part of the spaces in the intersected regions is A restriction condition adding step of setting a restriction condition that prevents any of the robots from passing through and adding the restriction condition to the action command list or the position information of the obstacle, and the operation command after the restriction condition adding step. Based on the list and the position information of the obstacle, the reference portion is moved from the start point to the end point while avoiding the obstacle. The teaching value of the fit, has a teaching value regeneration process to regenerate for each robot, and a teaching method which is characterized in that.

According to another aspect of the present invention, there is provided a teaching device including a computer that calculates, on a virtual space, trajectories of a plurality of robots arranged so as to have a common work area, and the display device based on the teaching value. said plurality of robot passage region wherein a set of trajectory points constituting each robot is drawn when operating the drive unit of each robot of the robot, is calculated in a virtual space for each robot Te, each robot A virtual obstacle as a constraint that prevents any of the plurality of robots from passing through at least a part of the space in the intersected area when the crossing area is detected . set, the robot passage region and the constraint condition is displayed on the display device, a new teaching value for moving to avoid the virtual obstacle, before A robot passing area, which is a set of trajectories drawn by the points constituting each robot when the driving unit of each robot is operated based on the new teaching value, is generated for each robot. It is a teaching device characterized in that it is calculated in space and displayed on the display device together with the virtual obstacle .
According to another aspect of the present invention, there is provided a teaching device including a computer that calculates, on a virtual space, trajectories of a plurality of robots arranged so as to have a common work area, and the display device based on the teaching value. Calculating a robot passing region, which is a set of trajectories drawn by points constituting each robot when the driving unit of each robot of the plurality of robots is operated, in the virtual space for each robot; As a restriction condition that prevents any of the plurality of robots from passing through at least a part of the space within the intersected area when the intersection is detected, Each robot must pass through a point on the line connecting the middle point of the line connecting two points intersecting each other and the origin of each robot. Set as derived point, the cause robot passage region and the via-points displayed on the display device, it is teaching device according to claim.

  The present invention provides a method for automatically teaching a plurality of robots arranged to have a common work area so that they do not interfere with each other without adjusting the operation timing. In addition, the present invention provides a teaching device that displays restriction conditions set in teaching on a display and facilitates the teaching work of an operator.

The block diagram of the apparatus which enforces the teaching method of this invention. 1 is a block diagram of a computer 10. FIG. The figure which shows the example of the robot arm which teaches operation | movement. 3 is a flowchart showing steps of a teaching method according to the first embodiment. The figure which shows the example of the starting point of a robot arm, a via-point, an end point, and an obstruction. The figure which shows the example which a robot passage area | region cross | intersects. The figure which shows the obstacle added virtually. The figure which shows the path | route regenerated after adding an obstacle virtually. 9 is a flowchart showing steps of a teaching method according to the second embodiment. The figure which shows the waypoint to add. The figure which shows the path | route regenerated after adding a waypoint. 10 is a flowchart showing steps of a teaching method according to the third embodiment. 10 is a flowchart showing steps of a teaching method according to the fourth embodiment.

  The teaching method of the present invention for teaching the operation of each robot using a computer in a system in which a plurality of robots are arranged so as to have a common work area will be described. For convenience of explanation, the meanings of terms used are described in advance.

(Reference part)
When teaching a target operation to each robot, it indicates a part whose position needs to be determined in advance, for example, a hand portion of each robot.
(Operation command list)
It is a list including position information of a start point, a via point, and an end point to be taken by the reference portion of each robot in a series of operations to be taught.
(Route)
This is a trajectory through which the reference part passes when the reference part is moved from the start point to the end point of the operation command list while avoiding an obstacle.
(Teaching value)
A set of teaching points such as a start point, a transit point, and an end point to avoid an obstacle.
(Drive part)
When operating a robot, it refers to a mechanism that is driven according to a drive instruction value, for example, a joint mechanism that can be rotated by a motor or an arm mechanism that can be expanded and contracted.

(Robot passage area)
This is a set of trajectories in the virtual space through which each point constituting the robot passes when the robot drive unit is driven based on the teaching value in the virtual space. That is, the robot passing area is a virtual space that represents a sweep space (a set of three-dimensional trajectories) when a robot, which is a tangible object, moves according to a teaching value.

(Restrictions)
When the passing areas of multiple robots intersect (spatial overlap), the computer is set so that no robot can pass through at least a part of the space in the area where the intersection occurs. This is the condition to set.

Below, the aspect of the teaching method of this invention is demonstrated concretely.
First, a computer as a teaching device stores an operation command list including position information of starting points, via points, and ending points to be taken by a reference portion of each robot in a series of operations to be taught. Here, the reference portion refers to a portion whose position needs to be determined when the robot performs a target operation, and is typically a hand portion of each robot.
Further, the computer as the teaching device stores information on the position and shape of the obstacles within the operation range of each robot.

  When the operation command list and the information on the position and shape of the obstacle are stored, the computer, based on the information, sets a waypoint, that is, a teaching value for moving the reference part of each robot avoiding the obstacle from the start point to the end point. The robot is generated independently. Here, generating independently means generating without considering interference with a path of another robot.

  Along with the route, in order to move the reference portion along the route, a drive instruction value to be given to the drive unit based on the teaching value is independently generated for each robot. Here, the drive unit refers to a mechanism that is driven when the robot is operated, such as a joint that is rotated by motor drive according to a drive instruction value, or an arm that expands and contracts according to the drive instruction value.

  Next, when the computer drives the robot drive unit in the virtual space based on the teaching value, each of the robot passing regions, which are a set of trajectories in the virtual space through which each point constituting the robot passes, Calculate and store the robot. In other words, the robot passage area is a sweep space (a set of three-dimensional trajectories) when a robot that is a tangible object is virtually operated according to a teaching value, and if it is a point that constitutes the robot, It always moves in the robot passage area.

Next, the computer uses the stored robot passage area data to determine whether the passage areas intersect (spatial overlap).
If no intersection is detected, the teaching value is adopted as it is.

  On the other hand, when an intersection is detected, the computer sets a restriction condition that no robot can pass through at least a part of the area where the intersection has occurred, and sets the restriction condition in the operation command list or the obstacle information. to add.

  In one aspect of the present invention, the constraint condition is added by the computer setting a virtual obstacle in an area where the robot passage areas intersect, and the computer additionally providing information on the position and shape of the virtual obstacle. This is done by storing in

  In another aspect of the present invention, the constraint condition is that the reference point of each robot starts from a point on the line segment connecting the midpoint of the line connecting the two points where the robot passage area intersects and the origin of each robot. It is set as a waypoint that must be routed on the way from to the end point. The constraint condition is added by the computer adding the stored waypoints to the operation command list and storing them.

When the constraint condition is added, the computer sets a teaching value for moving the reference part from the start point to the end point while avoiding the obstacle based on the added operation command list and the position and form information of the obstacle. , Regenerate for each robot.
According to the teaching method of the present invention, it is not necessary to adjust the operation timing of each robot in order to avoid interference between the robots.

  If the system is a simple system in which only two robots perform a planar operation, the regenerated teaching value may be adopted as it is. However, if the number of robots is large or the system includes complicated three-dimensional movements, the robot passage areas are calculated again based on the regenerated teaching values, and it is confirmed whether the robot passage areas do not cross each other. It is good to do. When a new intersection is confirmed with the regenerated teaching value, the computer adds a constraint that prevents any robot from passing through at least a part of the area where the new intersection has occurred. To do. Then, the teaching value is regenerated based on the operation command list after the addition and the information on the position and form of the obstacle.

  As described above, the computer can repeatedly generate a teaching value in which a plurality of robots do not interfere with each other by repeatedly confirming the intersection of the robot passage areas and regenerating the teaching value.

  A robot teaching method and teaching apparatus according to embodiments of the present invention will be described below with reference to the drawings. The robot targeted by the teaching method may be anything as long as it is operated and controlled by a power source such as a motor. For example, a robot having an articulated mechanism and a robot moving on a plane are included.

Example 1
In the embodiment, an example in which two serial link type robot arms having rotating joints are taught will be described.

(Configuration of teaching device)
1 and 2 show the configuration of a robot teaching system according to Embodiment 1 of the present invention. FIG. 1 is a diagram showing the configuration of the entire robot teaching system, and FIG. 2 is a block diagram of a computer that implements the teaching method.

  In FIG. 1, an arithmetic processing unit 1 that is a part of a computer 10 generates a teaching value for controlling the operations of a plurality of robots arranged sharing a work area. Although details will be described later, in this embodiment, the computer 10 generates a teaching value that allows the two robot arms to operate without interfering with each other while avoiding an obstacle. A program for this purpose is stored in a storage medium and can be read when the computer executes it.

  Here, the obstacle refers to an object other than the robot arm arranged within the operation range of the robot arm, and is arranged in a work area in the real space such as a component supply device, a ventilation duct, or a robot system housing. All objects that are made are included. In the virtual space used by the computer 10 to simulate the operation of the robot arm, obstacles having positions and shapes corresponding to the obstacles in the real space are arranged. Obstacle data arranged in the virtual space may be generated by the arithmetic processing unit 1 or may be introduced from the external device 32 to the computer 10 via the network interface 31.

A keyboard 11 and a mouse 12 (or a pointing device such as a track pad) are connected to the arithmetic processing unit 1 as input units for inputting operation commands, data, and the like. The operator inputs an operation command for the robot arm using the keyboard 11 and the mouse 12. In the present embodiment, the worker inputs the three-dimensional coordinate data of the start point, the via point, the end point, etc. of the hand part of the tip of the robot arm as the operation command for the work operation to be taught, and stores it in the computer 10.
In addition, a display 13 is connected as a display device for confirming an operation command input by an operator, a robot passage area generated by the arithmetic processing unit 1 based on the operation command, a constraint condition, or a virtual obstacle.

  An external storage device 14 and a network interface 31 can be connected to the arithmetic processing unit 1. The external storage device 14 in FIG. 1 is mainly composed of a disk device such as an external HDD or SSD, or various optical disk devices. The network interface 31 is used to transfer operation command data and the like to the actual robot arm.

  The external storage device 14 and the network interface 31 can be used as an install / update means for installing the trajectory generation program in the arithmetic processing unit 1 or updating the installed program. In this case, for example, the external storage device 14 can be constituted by an optical disk device capable of exchanging media. A control program for carrying out the present invention can be installed in the arithmetic processing unit 1 via the optical disk and can be updated. Similarly, a control program for carrying out the present invention can be installed in the arithmetic processing unit 1 by using a predetermined network protocol via the network interface 31 and can be updated.

  1 may be connected to an actual robot arm to be taught, and is configured to generate a teaching value even in an offline environment without connection to the robot arm. ing. In the teaching value generation in the offline environment, 3D virtual display of the robot arm to be programmed is performed on the display 13. Such a 3D virtual display GUI can be configured such that an arm or a joint thereof virtually displayed on the display 13 can be operated using the keyboard 11, the mouse 12, or the like.

  FIG. 2 shows an example of the configuration of the computer 10 as a block diagram. As shown in the figure, the computer 10 is configured by connecting various components such as a CPU 20, a ROM 21, a RAM 22, and an HDD 23 (for example, those built in the casing of the arithmetic processing unit 1) on a system bus 29.

  The external storage device 14 is connected to the system bus 29 via the interface 28. In FIG. 2, an optical disk device is illustrated as a member that constitutes the external storage device 14 in particular. Such a disk device is shown as a recording disk drive 24 in FIG. The recording disk drive 24 can read data on the recording disk 15 configured in a format such as various optical disks, or can further write data to the recording disk 15. Therefore, the recording disk 15 can be used for input / output of a control program for implementing the present invention, for example. In that case, the recording disk 15 constitutes a computer-readable recording medium of the control program.

  FIG. 3 is a diagram showing a robot to be instructed to operate, and shows two robot arms arranged in a common work area 30. The robot arm 5 includes three rotary joints 51, 52, and 53, and a hand 54 at the tip of the robot arm. Similarly, the robot arm 6 includes three rotary joints 61, 62, 63 and a hand 64. The rotary joint 51 of the robot arm 5 and the rotary joint 61 of the robot arm 6 are respectively fixed to the base of the work area 30. The position on the base where the rotary joint 51 and the rotary joint 61 are fixed is called the origin of each robot arm. Each robot arm operates along the paper surface direction of FIG. 3 by driving a rotary joint.

(Teaching method)
Hereinafter, the teaching method according to the first embodiment will be described in detail with reference to FIGS.
FIG. 4 is a flowchart showing the steps of the teaching method, and includes the following six steps. S100 is an operation command preparation step, S110 is a teaching value generation step for generating a teaching value for the robot to avoid an obstacle, S120 is a robot passage region calculation step for generating a robot passage region in the virtual space, and S130 is a passage through the robot. This is an intersection detection step of detecting an intersection of regions. Further, S140 is a constraint condition adding step for adding a virtual obstacle as a constraint condition, and S150 is a teaching value regenerating step for regenerating a teaching value for the robot to avoid the obstacle after the constraint condition adding step. The program including the above six steps is provided in the ROM 21 of the arithmetic processing unit 1.

In the operation command preparation step S100, first, an instructor inputs an operation command list which is information necessary for generating a teaching value. An operation command consists of a combination of a start point and an end point, and if necessary, a via point. A plurality of motion commands can be assigned to each robot.
As a method of giving an operation command, a point serving as a reference of the robot arm is determined (the tip of the hand in this embodiment), and information on the start point, via point, and end point of the position of the reference point in the operation to be taught is given.

  Further, in S100, the computer 10 stores information on the position and shape of the obstacle present in the common work area 30 of the two robot arms. In this embodiment, it is assumed that there are two obstacles 100 and 101 in the work area.

  FIG. 5 exemplifies the start point, the waypoint, and the end point given to teach the robot arm 5 and the robot arm 6 about the work. The reference part of the robot arm 5 is the tip of the hand 54. In FIG. 5, a1 is the start point, a2 is the via point, and a3 is the end point. This can be interpreted that the robot arm 5 moves from the start point a1 to the end point a2, and then moves from the start point a2 to the end point a3. The reference part of the robot arm 6 is the tip of the hand 64. In FIG. 5, b1 is the start point and b2 is the end point.

The following two operation commands are given to the robot arm 5 and are referred to as operation commands Oa1 and Oa2, respectively.
Oa1 = {a1, a2}
Oa2 = {a2, a3}
This means that the robot arm 5 moves from the start point a1 to the end point a2, and then moves from the start point a2 to the end point a3.
Further, one operation command is given to the robot arm 6 and is set as the operation command Ob1.
Ob1 = {b1, b2}
For the robot arm 6, this means that the robot arm 6 moves from the start point b1 to the end point b2.

  In the teaching value generation step S110, the computer 10 generates a waypoint (teaching value) necessary for moving the robot arm while avoiding the obstacle 100 and the obstacle 101 based on the operation command. The computer 10 stores in advance information necessary for generating a route and a teaching value, such as the link shape and length of each robot arm and the movable range of each drive unit (joint).

  Here, when generating the path and the teaching value of each robot arm, it is generated independently for each robot arm without considering interference with other robot arms. That is, generation is performed without recognizing other robot arms as obstacles.

  Specifically, the teaching value generation step S110 includes three sub-steps of route planning, route shortening, and driving value calculation.

  In the route planning process, a route for avoiding an obstacle between the start point and the end point is obtained. In order to obtain the route, it is possible to use a method of automatically calculating by various known methods such as RRT and PRM.

  In the route shortening step, the route generated by the route planning step is corrected. When a method using random search is selected in the route planning process, the route to be generated has a detour or a sudden change in angle, and thus the route needs to be corrected. In this route shortening process, there are many ways to shorten the route, such as searching for points that can be connected without interference between points in the route, and smoothing the route by approximating with a spline curve. Any method may be used.

  In the driving value calculation process, the rotational speed and acceleration of each driving unit (joint) of the robot arm is based on the teaching value so that the path generated by the path planning / path shortening process can be operated in the shortest time. Is calculated and an instruction value to the drive unit is generated. The interference with other robots is generated without consideration here.

FIG. 6 schematically shows paths generated based on the operation commands Oa1, Oa2, and Ob1.
As for the robot arm 5, as shown in FIG. 6, a path rTra1 along which the tip of the hand that is a reference part moves is generated based on the operation command Oa1, and a path rTra2 is generated based on the operation command Oa2. For the robot arm 6, a path rTrb1 along which the tip of the hand that is the reference part moves is generated based on Ob1.

  Next, in step S120 of FIG. 4, when the computer 10 drives the driving unit of the robot based on the teaching value, the computer 10 is a set of trajectories (sweep space) on the virtual space through which each point constituting the robot passes. Generate a robot passage area. In FIG. 6, the robot passage area 500 of the robot arm 5 and the robot passage area 600 of the robot arm 6 are schematically shown as hatched areas. The computer 10 displays the obstacles shown in FIG. 6, the robot passage area of each robot arm, and the like on the display 13, thereby facilitating the operator's teaching work.

  In step S130 of FIG. 4, the computer 10 calculates by calculation whether the robot passage area 500 of the robot arm 5 and the robot passage area 600 of the robot arm 6 intersect (overlap) in the virtual space. judge.

  In the example of FIG. 6, the robot passage area 500 and the robot passage area 600 have an intersection (overlapping) portion, and the robot arms interfere with each other when the robot arms are driven with the teaching values generated in the teaching value generation step S <b> 110. I understand that.

  If no intersection (overlap) between the robot passage areas is detected, that is, if step S130 is No, the computer 10 adopts and stores the already generated teaching value. However, when an intersection (overlap) is detected as in the example of FIG. 6, that is, when Step S <b> 130 is Yes, a constraint condition is set and the teaching value is regenerated. The computer 10 displays the set constraint conditions and the like on the display 13 to facilitate the operator's teaching work.

  In the first embodiment, for at least a part of an area where the robot passage areas intersect (overlapping), information on a virtual obstacle that cannot be passed by any robot is newly generated as a restriction condition to obtain obstacle information. It is added (S140), and the teaching value is regenerated under the conditions (S150). The computer 10 displays information on virtual obstacles set as a constraint condition on the display 13 to facilitate the teaching work of the operator.

Specifically, as shown in FIG. 6, the robot passage area 500 and the robot passage area 600 intersect in the path rTra1 and the path rTrb1, but do not intersect in the path rTra2 and the path rTrb1.
Therefore, in step S140, a virtual obstacle addition process is performed for the intersecting route rTra1 and route rTrb1. FIG. 7 is a diagram for explaining this. First, as shown in FIG. 7, the points Int1 and Int2, which are the intersections of the robot passage areas on the route rTra1 and the route rTrb1, are calculated. Next, a line connecting the points Int1 and Int2 is calculated, and this is added to the obstacle information as a new virtual obstacle w1. In this example, one virtual obstacle is added, but a plurality of obstacles are added if they intersect at a plurality of locations.

In step S150, a route is regenerated so as to avoid the virtual obstacle added in step S140. FIG. 8 shows the result of re-creating the route with the virtual obstacle w1 added. The route based on the operation command Oa1 was initially rTra1, but a new route Tra1 was generated by adding the obstacle w1. In addition, a new route Trb1 is generated as the route rTrb1 based on the operation command Ob1. Regarding the route rTra2 based on the operation command Oa2, since the robot passage areas of the robot arm 6 have not intersected from the beginning, the route remains unchanged. The computer 10 displays the obstacle shown in FIG. 8, a virtual obstacle, a robot passage area of each robot arm based on the regenerated route, and the like on the display 13, thereby facilitating the operator's teaching work.
The computer 10 stores the waypoint corresponding to the newly generated route as the changed teaching value.

  As described above, the path Tra1 and path Tra2 of the robot arm 5 and the path Trb1 of the robot arm 6 and the corresponding teaching value are obtained. It can be said that the regenerated path and the teaching value are considered in consideration of the operation of another robot. As can be seen from FIG. 8, since the robot passing areas do not intersect each other, it is understood that the robot arm interference can be prevented without performing control such as operation timing and speed adjustment.

  In the first embodiment, since the robot arm that operates in a plane is described, the virtual obstacle is represented by a line. However, in an articulated robot or the like that operates three-dimensionally, a virtual obstacle to be added may need to be expressed in a plane or a solid. The computer 10 displays an obstacle, a virtual obstacle, a robot passage area of each robot arm, and the like on the display 13 using an image expressed three-dimensionally, thereby facilitating the operator's teaching work. . In such a case, it is preferable to use a sweep space technique capable of obtaining a region through which the object has passed due to the movement of the object.

If sweep space technology is applied, calculate the area where the robot link sweeps along the path for one robot arm, and interfere with that area when the other robot arm is moved along the path. Can be determined. By calculating two points, that is, a point at which interference starts in the swept region and a point at which interference does not occur, the points Int1 and Int2 that are the intersection points can be obtained in the three-dimensional space, as in the first embodiment. Next, a virtual obstacle having a planar or three-dimensional shape including two points on the three-dimensional space is generated. For example, in step S140, a plane obtained by extending a line segment connecting two points in the height direction of the robot arm may be generated as an obstacle to be added. Alternatively, a cylinder having a line segment connecting two points as an axis may be generated as a virtual obstacle.
As described above, the teaching method of the first embodiment can be applied to a robot that moves in a three-dimensional space.

(Example 2)
In the second embodiment, the robot teaching system shown in FIGS. 1 and 2 is used to teach two serial link type robot arms having the rotary joint shown in FIG. Parts that overlap with the description of the first embodiment are omitted here.

In the first embodiment, a robot passing area is obtained, and when an intersection is detected, a virtual obstacle is added to at least a part of the intersecting area, and a path is generated again to interfere with other robot arms. Not generated routes and teaching values were generated.
On the other hand, in the second embodiment, the route is corrected by additionally setting a waypoint for avoiding the intersection of the robot passage areas instead of the virtual obstacle. Here, the via point is the point that the robot arm must pass from the start point to the end point, and the route of the robot arm can be corrected by placing the via point at an appropriate position. It becomes possible.
Hereinafter, a teaching method according to the second embodiment including a method of adding via points will be described.

  FIG. 9 is a flowchart showing the steps of the teaching method according to the second embodiment, and includes the following six steps. S100 is an operation command preparation step, S110 is a teaching value generation step for generating a teaching value for the robot to avoid an obstacle, S120 is a robot passage region calculation step for generating a robot passage region in the virtual space, and S130 is a passage through the robot. This is an intersection detection step of detecting an intersection of regions. Further, S240 is a constraint condition adding step for adding a via point as a constraint condition, and S250 is a teach value regenerating step for regenerating a teach value for the robot to avoid an obstacle after the constraint condition adding step. The program including the above six steps is provided in the ROM 21 of the arithmetic processing unit 1.

Among these, the steps S100 to S130 are the same as those in the first embodiment. Also in the second embodiment, as in the first embodiment, it is assumed that the robot passage areas of FIG. 6 are generated in step S120, and the intersection (overlap) of the robot passage areas is detected in step S130.
In the first embodiment, when an intersection is detected, a virtual obstacle is added as a constraint in step S140 in FIG. 4, but in the second embodiment, a via point is used as a constraint in step S240 in FIG. to add.

  First, as shown in FIG. 10, M1 which is an intermediate point of a line segment connecting the points Int1 and Int2 is obtained by calculation from points Int1 and Int2 where the robot passage areas of the route rTra1 and the route rTrb1 intersect. The intermediate point M1 is preferably a midpoint that equally divides the line segment as shown, but may be another point on the line segment. A line segment connecting the intermediate point M1 and the origin of the robot arm 5 (position on the base to which the rotary joint 51 is fixed) is denoted by la, and the origin of the intermediate point M1 and the robot arm 6 (the rotary joint 61 is fixed). A line segment connecting positions on the base) is defined as lb. The points on each line segment when the line segments la and lb are divided at an arbitrary ratio are Sa1 and Sb1, and these are added as via points when a route is generated again. The computer 10 displays on the display 13 the points Int1, Int2, the intermediate point M1, the waypoints Sa1, Sb1, and the like at which the obstacles and the robot passage area intersect, as shown in FIG.

  Various methods are conceivable for setting the ratio when dividing the line segments la and lb. For example, the ratio may be set so that the distance between Sa1 and Sb1 is longer than the minimum clearance that is required to be secured in order to operate the two robot arms. Further, the ratio may be set according to the time for operating the routes rTra1 and rTrb1.

By adding a waypoint, a constraint condition in which none of the plurality of robots can pass is set in a space where the robot passage regions intersect. When a via point is added, the teaching value generated in S110 is changed. For the robot arm 5, the operation command Oa1 is divided and changed to an operation command Oa1-1 from the start point a1 to the transit point Sa1 and an operation command Oa1-2 from the transit point Sa1 to the end point a2. Therefore, the operation command for the robot arm 5 is as follows.
Oa1-1 = {a1, Sa1}, Oa1-2 = {Sa1, a2}, Oa2 = {a2, a3}
Similarly, the operation command for the robot arm 6 is as follows.
Ob1-1 = {b1, Sb1}, Ob1-2 = {Sb1, b2}
In S250 of FIG. 9, the teaching value is generated again based on the changed operation command.

  FIG. 11 is a diagram illustrating a path of a reference portion when moving each robot arm while avoiding the obstacle 100 and the obstacle 101 based on the regenerated teaching value. Routes Tra1-1 and Tra1-2 that pass through the route point Sa1 are generated for the initial route rTra1, and routes Trb1-1 and Trb1-2 that pass through the route point Sb1 are also generated for the route rTrb1. As described above, the path of each robot arm and the teaching value corresponding thereto are obtained. The computer 10 displays the obstacle passing points shown in FIG. 11, the robot passage area of each robot arm based on the regenerated route, and the like on the display 13 to facilitate the operator's teaching work.

Even in the method of adding a new waypoint as in the second embodiment, it is possible to generate a route in which the robot arms do not interfere with each other. The method of adding a waypoint is characterized in that it is easy to intentionally correct the route because the position where the waypoint is added can be determined arbitrarily. This means that, for example, it is possible to adjust such that one robot is operated with a short operation time and the other robot is operated with a long operation time.
In the second embodiment, the robot arm that operates in a planar manner has been described, but the present invention can also be applied to a robot that moves in a three-dimensional space.

(Example 3)
In the first embodiment, an example of two robot arms operating in a plane has been described. However, when a robot operating three-dimensionally or a large number of robots share a work area, the flowchart of FIG. , May not always be enough. Even if a virtual obstacle is added and the route is regenerated in step S140, the robot passing regions may not necessarily intersect with each other on the regenerated route.

  Therefore, in the third embodiment, a process flow changed as shown in FIG. 12 is used. That is, if the route and the teaching value are regenerated under the condition that a virtual obstacle is added in step S150, the robot passing region is generated based on the teaching value regenerated by returning to step S120, instead of ending as it is. In step S130, it is determined whether or not there is an intersection. In this way, it is possible to reliably generate a path and a teaching value without an intersection by forming a feedback loop and repeating the addition of the constraint condition and the generation of the teaching value again until no intersection is detected. is there. The computer 10 displays obstacles, virtual obstacles, robot passage areas, and the like on the display 13 at each stage of the process flow of FIG. 12, thereby facilitating the operator's teaching work.

Example 4
In the second embodiment, an example of two robot arms that operate in a planar manner has been described. However, when a robot that operates three-dimensionally or a large number of robots share a work area, the flowchart of FIG. , May not always be enough. Even if the route is regenerated by adding a waypoint in step S240, there may be a case where the robot passing areas do not always intersect each other on the regenerated route.

  Therefore, in the fourth embodiment, a process flow changed as shown in FIG. 13 is used. That is, if the route and the teaching value are regenerated under the condition that the waypoint is added in step S250, the process does not end as it is, but returns to step S120 to generate a robot passing area based on the regenerated teaching value, In S130, it is determined whether or not there is an intersection. In this way, it is possible to reliably generate a path and a teaching value without an intersection by forming a feedback loop and repeating the addition of the constraint condition and the generation of the teaching value again until no intersection is detected. is there. The computer 10 displays obstacles, waypoints, robot passage areas, and the like on the display 13 at each stage of the process flow of FIG. 13 to facilitate the teaching work of the operator.

(Other examples)
The implementation of the present invention is not limited to the four embodiments described above, and can be changed or combined as appropriate. For example, the shape of the common work area, the number and type of installed robots, the installation position, etc. are not limited to the above example. Further, the configuration of the computer that generates the teaching value is not limited to the above example.

  The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  DESCRIPTION OF SYMBOLS 1 ... Operation processing part / 5 ... Robot arm / 6 ... Robot arm / 10 ... Computer / 100 ... Obstacle / 101 ... Obstacle / 500 ... Robot arm 5 Robot passing area / 600 ... Robot passing area of the robot arm 6 / a1 ... start point / a2 ... via point / a3 ... end point / b1 ... start point / b2 ... end point / rTra1, rTra2 ... Robot arm 5 path / rTrb1 ... Robot arm 6 path / w1 ... Virtual obstacle / Tra1 ... Regenerated robot arm 5 path / Trb1 ... Regenerated robot Route of arm 6 / M1... Midpoint of line segment connecting intersection areas / sa1... Via point added to route of robot arm 5 / sb1... Route point added to route of robot arm 6

Claims (13)

A teaching method for teaching a plurality of robots arranged to have a common work area using a computer,
A step in which the computer stores an operation command list including position information of a start point, a via point, and an end point of each robot's reference site for the operation to be taught;
Storing information on the position and shape of obstacles within the operating range of the plurality of robots;
Based on the operation command list and information on the position and shape of the obstacle, the computer sets an additional via point for each robot to move the reference portion from the start point to the end point while avoiding the obstacle. A teaching value generation step that is independently generated and stored as a teaching value;
When the computer operates the driving unit of each robot based on the teaching value, a robot passing area, which is a set of trajectories drawn by points constituting each robot, is calculated for each robot in a virtual space. A robot passing area calculating step to store,
The computer detects the presence or absence of intersection between the passing areas of each robot calculated in the robot passing area calculation step,
When the computer detects an intersection in the intersection detection step, the computer sets a restriction condition that prevents any of the plurality of robots from passing through at least a part of the space in the intersected area, A constraint condition adding step to add to the position information of the obstacle;
Based on the operation command list after the constraint condition adding step and the position information of the obstacle, the computer uses a teaching value for moving the reference part from the start point to the end point while avoiding the obstacle. A teaching value regeneration step for regenerating each robot.
A teaching method characterized by the above. The computer re-executes the robot passage area calculation step and the intersection detection step based on the teaching value of each robot regenerated in the teaching value regeneration step.
The teaching method according to claim 1. The constraint condition adding step includes:
The computer sets a virtual obstacle in an area where the robot passage areas of the respective robots intersect with each other, and adds information on the position and shape of the virtual obstacle to the position and shape information of the obstacle. It is a process to add,
The teaching method according to claim 1 or 2, wherein The constraint condition adding step includes:
Each robot has a point on a line segment connecting an intermediate point of a line connecting two points where the robot passing areas of each robot intersect with each other and an origin of each robot from the start point to the end point. It is a step of setting as a waypoint that must be routed on the way and adding to the operation command list.
The teaching method according to claim 1 or 2, wherein The reference part is a hand provided in the robot.
The teaching method according to any one of claims 1 to 4, wherein: The plurality of robots are operated based on the teaching value generated by the teaching method according to any one of claims 1 to 5.
A method for operating a plurality of robots.   A program for causing a computer to execute the teaching method according to any one of claims 1 to 5.   A storage medium storing a program for causing a computer to execute the teaching method according to claim 1. A computer,
An apparatus storing the program according to claim 6.
A teaching device. In a teaching device having a computer that calculates, in a virtual space, trajectories of a plurality of robots arranged to have a common work area, and a display device,
The computer
The robot passage region wherein a set of trajectory points draws constituting each robot when based on the teaching values by operating the driving portion of each robot of said plurality of robots, calculated in a virtual space for each robot to detect the presence or absence of the intersection of the passage region between the each robot,
When an intersection is detected, a virtual obstacle is set as a constraint that prevents any of the plurality of robots from passing through at least a part of the space in the intersected region, and the robot passage region and the constraint Is displayed on the display device ,
A new teaching value for moving around the virtual obstacle is generated for each robot,
A robot passing area, which is a set of trajectories drawn by points constituting each robot when the driving unit of each robot is operated based on the new teaching value, is calculated for each robot in a virtual space; Displaying on the display device together with the virtual obstacle,
A teaching device. The computer sets the virtual obstacle on a line segment connecting two points where the robot passage area intersects each other.
Teaching device according to claim 1 0, characterized in that. In a teaching device having a computer that calculates, in a virtual space, trajectories of a plurality of robots arranged to have a common work area, and a display device,
The computer
Based on the teaching value, a robot passing area, which is a set of trajectories drawn by points constituting each of the robots when the driving unit of each of the plurality of robots is operated, is calculated for each robot in a virtual space. , Detecting the presence or absence of crossing between the passing areas of each robot,
When a crossing is detected, as a constraint that prevents any of the plurality of robots from passing through at least a part of the space in the crossing region, a line segment connecting two points where the robot passing region crosses each other a point on line segment connecting the said intermediate point of each robot origin, the set as route point that must traverse the robot is to display the via-point and the robot passing area on the display device ,
Teaching shows device you wherein a. The computer generates a new teaching value for each robot to be moved via the waypoint,
The robot passage region which is a set of trajectory points draws constituting each robot when said based on the new teaching value by operating the driving portion of the each robot, it calculates in a virtual space for each robot, Display on the display device together with the waypoint,
Teaching device according to claim 1 2, characterized in that.

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