JPH08166809A - Method for evading interference of plural robots and method for determining order and partial charge of operation - Google Patents

Abstract

PURPOSE: To obtain the interference evading method for plural robots and operation order and operation partial charge determining method which can securely evade the mutual interference between the robots and make a robot stop time extremely short. CONSTITUTION: The priority levels of the operations of the respective robots are set (S1), areas that the robots are expected to pass through when operating in a specific time or occupation areas including them are computed in order (S2), and it is decided whether or not the occupation areas overlap with one another (S3); when they overlap, the robot having low priority are made to stand by and the robot having high priority is placed in operation (S5). Then the occupation areas of the other robot where the robot has finished its operation are reset in order (S6) and after the overlap is eliminated as the occupation areas of the other robot change, the operation of one robot is started (S7) Consequently, the mutual interference between the robots can securely be evaded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for avoiding interference between a plurality of robots and a method for determining a work order / work assignment, and more particularly, a method for avoiding mutual interference between a plurality of robots having a common movement space and each method. The present invention relates to a method for determining a work order and work assignment of a robot.

[0002]

2. Description of the Related Art Conventionally, as a method of avoiding mutual interference of a plurality of robots having a common moving space, the moving space is divided into an interference area and a non-interference area in advance, and a robot having a high priority interferes with each other. When in the area, robots with lower priority generally waited without entering the interference area. Furthermore, the space is divided into blocks, and n ~
There has been a method in which an area occupied in n + 1 steps is set as an occupied area and interference occurs when there is a common block. In this case, if the time of n to n + 1 steps is not uniform, an interpolation step is provided (Japanese Patent Laid-Open No. 61-260306).
(See the official gazette). On the other hand, when the work is performed by a plurality of robots, the work order and the assignment determination method of each robot are conventionally determined by humans and teaching is performed.

[0003]

The conventional interference avoidance method for a plurality of robots as described above has the following problems. (1) In the method of dividing the interference area in advance, even if a plurality of robots enter the interference area, there is a case where the robots do not interfere with each other, but the robot with a low priority cannot enter the area. For this reason, there was a tendency for the robot stop time to increase due to mutual interference between robots. (2) In the method of dividing the interference space into blocks, the smaller the size of the blocks, the shorter the robot stop time, but the longer the calculation time. Also, since the interference is determined based on the presence / absence of a common block, even if it is determined that there is no interference, or if it is determined that there is no interference in adjacent blocks, depending on the robot position in the block, There was a risk that the robots would approach each other and interfere with each other. In addition, in the conventional work order / work assignment determination method for multiple robots, when the work to be performed by multiple robots increases, the work order and work assignment become very large, so the total work time is the shortest. It was difficult to decide the order of work and the division of labor. The present invention has been made in view of the above circumstances. A first object of the present invention is to provide a plurality of robots capable of reliably avoiding mutual interference between robots and significantly reducing robot stop time. Is to provide a method of avoiding interference. The second purpose is to determine the work order and work assignment of each robot so that the total work time is the shortest when the work is performed by the plurality of robots. The purpose is to provide a method of determining the sharing.

[0004]

In order to achieve the above first object, a first invention is a method for avoiding mutual interference between a plurality of robots having a common moving space, and prioritizing the operation of each robot. Set the order, sequentially calculate the occupancy area that is the expected passage area of the robot or the expanded area including it by the movement of each robot within the predetermined time, and judge whether there is overlap between the calculated occupancy areas, If there is an overlap, one of the robots with lower priority is placed on standby, and the other robot with higher priority is operated.
The occupying area of the other robot is released in sequence for the parts that have already finished moving during the operation of the other robot, and based on the change of the occupying area of the other robot, after the overlap disappears, It is configured as a method for avoiding interference of a plurality of robots, characterized in that the operation of one robot is started. In order to achieve the above-mentioned second object, the second invention is a method for determining the work order / work sharing of a plurality of robots having a common moving space, in which the first work of a certain robot is selected in advance. Aside
The priority of each robot's motion is set, and the occupied area, which is an expanded area including the planned passage area of the robot due to the motion of each robot within a predetermined time, is sequentially calculated, and the overlap between the calculated occupied areas If there is no overlap, and if there is no overlap, each robot is selected based on the distance between the unselected work and the work selected immediately before, and the above-mentioned priority order, among the unselected works within the motion range of each robot. After sequentially selecting one work for each robot, each robot is operated for the selected work, and when there is an overlap, two or more robots with lower priority are placed on standby, and
From the unselected tasks within the motion range of the other robot with the highest priority, one task is selected based on the distance between the unselected task and the task selected immediately before, and then the other task is selected. Robots for the selected work,
The occupying area of the other robot is released in sequence for the parts that have already finished moving during the operation of the other robot, and based on the change of the occupying area of the other robot, after the overlap disappears, From the unselected tasks in the robot's waiting motion range, one task is sequentially selected for each robot based on the distance between the unselected task and the task selected immediately before and the priority. After that, the work order and work assignment of each robot are determined by sequentially operating the robots that have been put on standby for the selected work. It is configured as a sharing decision method. Furthermore, it is a method of determining the work order / work share of a plurality of robots in which the work order is the welding order and the work distribution is the welding share.

[0005]

According to the first aspect of the present invention, when avoiding mutual interference of a plurality of robots having a common movement space, the priority of each robot is set, and the robots pass by movements within a predetermined time of each robot. The planned area or the occupied area which is an expanded area including the planned area is sequentially calculated. Whether or not there is an overlap between the calculated occupied areas is determined, and if there is an overlap, one of the robots with a lower priority is put on standby and the other robot with a higher priority is operated. The occupying area of the other robot is sequentially released for the part of the other robot that is already in operation. The operation of the one robot is started after the overlap disappears based on the change of the occupied area of the other robot. Thus, by obtaining the interference area in a continuous area and updating the interference area at a certain time, mutual interference between the robots can be surely avoided, and the robot stop time can be extremely shortened. According to the second aspect of the present invention, when determining the work order / work assignment of a plurality of robots having a common movement space, the first work of a certain robot is selected in advance, the priority of each robot is set, and An occupied area, which is an expanded area including the planned passage area of the robot or an area through which the robot will pass, is sequentially calculated by the operation of the robot within a predetermined time. Whether or not there is an overlap between the calculated occupation areas is determined, and when there is no overlap, the unselected work and the work selected immediately before are selected from the unselected work within the operation range of each robot. One work is sequentially selected for each robot on the basis of the distance and the priority, and each robot is operated for the selected work. The above robots are put on standby, and one of the unselected tasks within the operation range of the other robot with the highest priority is selected based on the distance between the unselected task and the task selected immediately before. After a work is selected, the other robot is operated for the selected work. The occupying area of the other robot is sequentially released for the part of the other robot that is already in operation. After the overlap disappears based on the change in the occupied area of the other robot, the unselected work is selected immediately before the unselected work from the unselected work in the operation range of the robot that has been put on standby. One work is sequentially selected for each robot based on the distance to the work and the priority order, and the robots that have been on standby are sequentially operated for the selected work. The work order and work allocation are determined. In this way, the total work time can be minimized.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not intended to limit the technical scope of the present invention. 1 is a diagram showing a schematic flow of an interference avoidance method for a plurality of robots according to an embodiment (first embodiment) of the first invention, and FIG. 2 shows an apparatus to which the interference avoidance method is applicable. Example A
1 is a block diagram showing a schematic configuration in FIG. 1, FIG. 3 is a diagram showing a schematic operation flow of the interference avoidance device A1, FIG. 4 is a conceptual diagram of a reserved area, FIG. 5 is a conceptual diagram showing an overall configuration of a robot, FIG.
Is a conceptual diagram showing the envelope shape of the robot, FIG. 7 is a diagram showing the coordinate system of the reserved area, FIG. 8 is a flow chart showing the detailed operation procedure of the interference avoidance device A1, and FIG. 9 is a device to which the interference avoidance method is applicable. FIG. 10 is a block diagram showing a schematic configuration of another example A2 of the present invention, and FIG. 10 is a diagram showing a schematic flow of a work order / work sharing determination method for a plurality of robots according to an embodiment (second embodiment) of the second invention. , Fig. 11 is a conceptual diagram of a plurality of robots, Fig. 12 is a diagram showing a detailed flow of a welding order / weld sharing determination method of a plurality of welding robots, and Fig. 13 is a case where the robots of priority 1 and 2 are adjacent to each other. FIG. 14 is an explanatory view showing an example of determining the welding order, FIG. 14 is an explanatory view showing an example in which a robot moves between welding lines, FIG. 15 is an explanatory view showing a change example of an interference region at time t and t + T, and FIG. 16 is welding. Simulator, robot waiting for welding and buffer FIG. 17 is a block diagram showing the relationship of the welding determination mechanism, FIG. 17 is an explanatory diagram showing a work in which welding lines are arranged, and FIG. 18 is a chart showing the operation time chart of each robot with respect to the simulation time in the work and the registration state in the buffer. , FIG. 19 is an explanatory diagram showing a state during the simulation.

As shown in FIG. 1, an interference avoidance method for a plurality of robots according to an embodiment (first embodiment) of the first invention avoids mutual interference between a plurality of robots having a common moving space. In doing so, the priority order of the motions of the robots is set (S1), and the planned passage region of the robots due to the motions of the robots within a predetermined time or the occupied region that is an expanded region including the region is sequentially calculated (S2). Whether or not there is an overlap between the calculated occupied areas is determined (S3), and if there is no overlap, each robot is operated (S4), but if there is an overlap, one of the robots with the lower priority is on standby. At the same time, the other robot having the higher priority is operated (S5), and the occupied area of the other robot is sequentially released for the already completed part of the operation of the other robot ( 6), and it is configured to initiate operation of said one robot since when the overlap on the basis of changes in the occupied area of the other robot runs out (S7). The above priority may be set in advance,
For example, it may be dynamically determined such as a robot in operation or a robot with a lot of scraping work. FIG. 2 shows an apparatus A for realizing the above-mentioned robot interference avoidance method at the time of actual operation of the robot.
It is a schematic block diagram of 1. This device A1 has a system configuration in which the operations of a plurality of robots 1, 1, ... Having a common moving space are managed and controlled by a computer 3 connected to robot controllers 2, 2 ,. In addition, the computer 3 has a motion determination unit 4
And a memory 5 for storing an occupied area and a reserved area (an occupied area at the time of operation reservation). Then, a certain time interval transmitted from the robot controller 2, 2, ...
Alternatively, when one operation starts or one operation ends, an operation status flag (start, progress, end), current position, target position, and arrival time data is received, and the occupied area and the reserved area stored in the memory 5 are used to cause interference. Then, the operation permission and operation prohibition signals are transmitted to the robot controllers 2, 2, ....

Next, the processing of the motion judging section 4 will be described. FIG. 3 is a processing flow of the operation determination unit 4. When the operation status flag transmitted from the robot controller 2 is the start, the interference area from the current position to the target position is stored in the memory 5 as a reserved area. This is checked for the overlap with the occupied area already in the memory 5, and if there is an overlap, an operation prohibition signal is sent to the robot controller 2 of the transmission source. If there is no overlap, the reserved area is stored in the memory 5 as an occupied area. When the operation status flag transmitted from the robot controller 2 is in progress or has ended, the occupied area up to the current position is deleted from the occupied area. as a result,
If there is a robot in which the reserved area and the occupied area do not overlap each other, the reserved area is stored in the memory 5 as the occupied area, and the operable signal is transmitted to the robot controller 2. Next, how to obtain the occupied area will be described. FIG. 4 shows an example of how to obtain the occupied and reserved areas. Here, the method of obtaining the occupied area will be described by taking a robot as shown in FIG. 5 capable of moving in the XY directions as an example. However, the same can be applied to a robot in which the waist position of the robot is fixed. The current position and the target position are first transmitted from the robot controller 2. These positions may be the positions of all axes, or may be the positions of limited axes, such as the positions of the waist, upper bowl, and lower arm, in order to delete the traffic. Further, the region may be defined in three dimensions, or the projected coordinates on the XY plane may be obtained in order to reduce the interference time. In FIG. 4, the positions of the waist, upper bowl, and lower arm are received from the robot controller 2 and the interference determination is X.
-The projection coordinates on the Y plane are used.

The method of obtaining the occupied and reserved areas in this example will be described in more detail below. First, a rectangle that envelops the waist, upper bowl, and lower arm at the current position is calculated. Similarly, a rectangle enclosing the waist, upper bowl, and lower arm at the target position is obtained. Then each side of these rectangles is extended to a predefined risk area. The corresponding points of these rectangles are connected by straight lines, and the largest area is occupied and reserved. To obtain the area in three dimensions, the rectangle may be a rectangular parallelepiped. In this example, the rectangle that covers the three axes is the starting point and the target point area,
As shown in FIG. 6, each axis may be surrounded by a rectangle that extends to the dangerous area, and these areas may be overlapped. Such a reserved area is stored in the memory 5 for each robot 1 in a format as shown in FIG. FIG. 7 is an example of a storage format corresponding to the reserved area in FIG. When the start point and the end point are enveloped by a rectangle on a two-dimensional plane, the coordinates of the six corner points (p1 to p6 in FIG. 7) of the area are stored clockwise. A flag indicating whether the area is occupied or reserved is also stored for each robot 1.

Next, whether or not the reserved area and the occupied area overlap each other is determined by the flow shown in FIG. Now, consider a case where the number of robots is n and it is determined whether or not the m-th (0 <m <n + 1) reserved area and the occupied areas of the other n-1 robots overlap. First, six line segments surrounding the reserved and occupied areas are numbered 1 to 6. For example, line segment 1 is p
A line segment connecting 1, p2, ..., A line segment 6 is a line segment connecting p6, p1. Next, the number of robots (hereinafter referred to as “occupied robots”) having occupied areas, which are the objects of determination of the presence or absence of overlap, is set to 1. This is because m is equal and the occupied robot number is n.
If it is equal to, it is determined that there is no interference and the determination ends. The occupied robot number is equal to m and the occupied robot number is n
If it is not equal to, the overlap judgment is performed by adding 1 to the occupied robot number and setting it as a new occupied robot number. If the occupied robot number is not equal to m, overlap judgment is performed for the robot having the occupied robot number. The overlap determination is first performed from the line segment 1 of the robot m and the line segment 1 of the robot having the occupied robot number. If there is an intersection between the two line segments, it is determined that there is an overlap, and the determination ends. This is done for all combinations of line segments for each robot. further,
These determinations are performed for the robot having all occupied areas, and if there is no interference, it is determined that there is no interference and the determination ends. However, when one area is included in the other area, the above method cannot determine. Therefore, in that case, the interference check is performed by the intersection, and one point in one area is arbitrarily selected with respect to the one that is determined not to interfere, and if it is included in the other area, it is determined that there is interference. Here, the reason why one arbitrary point is sufficient is that, when it is judged that there is no interference by the check by the intersection, this one point is included in the other area or there is no overlap at all. Therefore, if even one point is inside, the interference area is included.

Next, FIG. 3 will be described in detail by taking the above-mentioned reservation and occupied area storage method as an example. Robot controller 2
When the motion status flag transmitted from the robot 1 is started, the interference area (p1 to p1) from the current position of the robot 1 to the target position is
The coordinate (p6) is stored in the memory 5 to which the operation reservation flag is assigned. Next, the overlap between this and the occupied area already in the memory 5 is checked by the above method, and if there is an overlap, an operation prohibition signal is sent to the robot controller 2 of the transmission source. If there is no overlap, the reserved area is stored in the memory 5 as an occupied area (reservation and occupied flag are changed). When the operation status flag transmitted from the robot controller 2 is in progress or has ended, the occupied area up to the current position is deleted from the occupied area. That is, the coordinates of p1 to p6 from the current position to the end position are stored in the memory 5. An interference check is performed between the robot 1 having all reserved areas and the robot 1 having the occupied area deleted. As a result, if there is a robot that does not overlap the reserved operation area and the occupied area,
The reserved area is stored in the memory 5 as an occupied area (reserved, the occupied flag is changed). Then, the operable signal is transmitted to the robot controller 2.

Next, another example A2 of the apparatus to which the above interference avoidance method can be applied will be briefly described. The schematic configuration of the device A2 is shown in FIG. Here, the management / control computer 3 is connected to a simulator for simulating the operation of a plurality of robots 1, 1, ... Instead of the robot controllers 2, 2, ... Or a simulator is built into the computer 3. By doing so, interference between multiple robots is avoided in order to create an optimal operation schedule. This will be described below. That is, FIG.
Is a robot that uses the robot interference avoidance method 1, 1, ...
2 shows a system configuration for creating an optimum operation schedule of. Here, instead of the robot controllers 2, 2, ..., By connecting or incorporating a robot operation simulator, a simulation can be performed without interfering with the plurality of robots 1, 1. As a result, the optimal work order can be obtained by changing the work order of each robot 1, 1 ... As described above, by obtaining the interference area in the continuous area and updating the interference area at every certain time, mutual interference between the robots can be surely avoided, and the robot stop time can be extremely shortened. In addition, since the occupied area and the like are expressed by a shape having a relatively small number of elements, the load on the memory and the CPU of the computer that performs the determination calculation is much smaller than that of the conventional method using blocks. As a result, it is possible to ensure optimum work efficiency with multiple robots. In the first embodiment described above, the interference avoidance method for a plurality of robots has been described, but this can be further applied to a work order / work assignment determination method for a plurality of robots. That is, when there is only one robot waiting for interference avoidance, the above-mentioned interference avoidance result can be used as it is for determining the operation order / operation sharing of a plurality of robots. However,
When there are two or more robots to be on standby, it is necessary to further determine the operation start order between these waiting robots. The second invention was made in view of this point and will be described below.

As shown in FIG. 10, the method of determining the order of operations and the allocation of operations of a plurality of robots according to an embodiment (second embodiment) of the second invention is that of a plurality of robots having a common moving space. When deciding the work order and work assignment, the first work of a certain robot is selected in advance (S10), the priority of the motion of each robot is set (S11), and the robot is operated by the motion of each robot within a predetermined time. The area to be passed through or the occupied area that is an expanded area including it is sequentially calculated (S
12), it is determined whether or not there is an overlap between the calculated occupied areas (S13), and if there is no overlap, the unselected work within the motion range of each robot is immediately before the unselected work. After sequentially selecting one work for each robot based on the distance to the selected work and the above priority,
Each robot is operated for the selected work (S14), but if there is an overlap, the two or more robots with the lower priority are put on standby and within the operation range of the other robot with the highest priority. Among the unselected tasks of the above, one task is selected based on the distance between the unselected task and the task selected immediately before, and the other robot is operated for the selected task ( S1
5) The occupying area of the other robot is sequentially released for the already completed portion of the operation of the other robot (S16), and there is no overlap based on the change of the occupying area of the other robot. From among the unselected tasks in the robot's operation range that have been on standby since the time when the task is performed, 1 is set for each robot based on the distance between the unselected task and the task selected immediately before and the priority. After sequentially selecting one work, the robot that has been put on standby is sequentially operated for the selected work (S17).
Thus, the work order and work sharing of each robot are determined (S18). Note that the above-mentioned priority order may be set in advance, for example, a robot in motion,
It may be determined dynamically like a robot with a lot of sawing work. The welding order and the welding share determination method will be described below by taking a welding system using a plurality of robots as shown in FIG. 11 as an example. However, it goes without saying that the invention can also be applied to a system composed of a plurality of other industrial robots such as assembly and painting. In the example of FIG. 11, two robots are installed side by side in a gate-type robot mounting device, and a system for welding one welding target by a total of 10 robots is shown. It can be moved in the X, Y, and Z directions. FIG. 12 shows a detailed flow for obtaining the welding order and welding allocation of each robot in such a welding system. The flow will be described below.

First, one welding line to be welded first to the robot having the highest priority set in advance is selected from the operating range of the robot (S21). Next, one robot having the highest priority is selected from the robots adjacent to the robot whose welding line has already been determined (S22).
Then, as the welding line from the welding line within the operation range of the selected robot, the welding line with the closest center position of the welding line is selected from the welding lines that do not interfere with other robots already decided to weld. Yes (S23). FIG. 13 shows an example of determining the welding line when the robots of priority 1 and 2 are adjacent to each other. It is assumed that the first welding line of the robot 1 is the welding line with the welding line number 1. When determining the welding line of the robot 2, first, among welding lines within the operating range of the robot 2 (in this case, 4 to 9), welding lines of other robots already decided to weld (in this case, Excluding the welding line (4 in this case) that causes interference during the welding work in 1). For example, as shown in FIG. 13, a certain occupied area (interference area) is set around the welding line to determine whether or not to interfere, and when the areas overlap each other, it is considered to interfere. From the welding lines that do not interfere (5 to 9 in this case), select the welding line with the shortest distance from the welding line 1. The distance Dj is set to (xi, yi) as the center coordinates of the welding line that has already been decided to be welded (i = 1 in this case), and within the operating range of the robot from which the welding line is to be determined, and If the center coordinates of the welding line of the robot that does not interfere with the welding line are (xj, yj) (j = 5 to 9 in this case), it can be obtained by the following formula.

[Equation 1] In the case of FIG. 13, the welding line 5 having the smallest distance Dj is selected.

Similarly, welding lines of other robots are selected (S24). In the case of FIG. 11, it is necessary to determine the welding line of the robot 10. In addition, when moving from the welding line to the welding line, interference may occur. Therefore, when checking the presence or absence of the above interference, the interference region is set also by using the portion surrounded by the movement region as shown in FIG. Is desirable. Next, a welding simulation is performed (S2
5). The simulation is performed by obtaining the position of the robot every certain simulation cycle (T seconds), and obtaining the interference region surrounding the position of the robot and the end point of the welding line during welding for each robot. In FIG. 15, time t
An example of a change in the interference region at t and T + T is shown. In addition, the simulation is performed every simulation time T seconds,
If there is a robot that has completed welding in the process of advancing the simulation, the robot number is registered in the welding waiting buffer. FIG. 16 shows the relationship between the welding simulator, the welding waiting robot buffer, and the welding line determination mechanism. The welding line simulator sends the position and size of the interference region at that time and the robot number of the welding completion robot, if any, at each simulation time interval T seconds to the welding line determination mechanism as data (S26). If there is a welding completion robot, the welding line determination mechanism registers the number in the welding waiting robot buffer (S27). Also, if there is a robot registered in the welding waiting robot buffer (S28), the welding line determination mechanism uses the same method as the above-described method (steps S22 to S24) according to the priority order, and the welding line is not yet welded. Then, the welding line to be welded next is determined (S29 to S31). At this time, even if there are welding lines that can be welded, all of them interfere with other welding lines, and if there is no next welding line to be welded, the welding line is not determined and the robot number waiting for welding is registered. .
For a robot for which the welding line to be welded has been determined, that robot number is deleted from the welding waiting robot buffer.

When the welding line determination mechanism finishes examining the determination and non-determination of the welding line for the robot in the welding waiting robot buffer, the determined welding line is sent to the simulator, and then the simulation is started (S32). Figure 1
The relationship between the motion simulation of each robot and the buffer will be described by taking a work having welding lines as shown in 7 as an example. In FIG. 17, the welding assignment and welding order of each robot are as follows: welding line 1-1 → 1-2 for robot 1, welding line 2-1 for robot 2, and welding line 3-1 → 3-for robot 3.
2. It is assumed that the robot 4 is the welding line 4-1. FIG. 18 shows an operation time chart of each robot with respect to the simulation time in this work and a state in the buffer. Here, in order to simplify the explanation, it is assumed that the moving time from the welding line to the next welding line as shown in FIG. 14 is not considered.

First, at time T0, four robots simultaneously start welding. The interference region at this time is shown in FIG. At this time, since there is no overlap in any interference area, any welding robot starts welding. Next, the welding of the welding line 2-1 of the robot 2 ends at time Ta, and the welding of the welding line 2-2 starts. At this time as well, there is no overlap in any interference region, so welding is continued (Fig. 19).
(See (a)). Next, at time Tb, the welding of the welding line 3-1 of the robot 3 is completed and the welding line 3-2 is tried to be welded, but an overlap with the interference region of the welding line 2-1 occurs (Fig. 19 ( The robot 3 is registered in the buffer. Next, at time Tc, welding of the welding line 1-1 of the robot 1 is completed and an attempt is made to weld the welding line 1-2, but there is an overlap with the welding line 2-2 (FIG. 19).
(See (c)), the robot 1 is registered in the buffer. That is, at this point, the robots 1, 3 are in the buffer.
Is registered. Next, at time Td, the welding line 2
Since there is no interference between -2 and 3-2, the robot 3 is deleted from the buffer and welding of the welding line 3-2 is started (see FIG. 19 (d)). Therefore, at this point, only the robot 1 is registered in the buffer. Next, at time Te, since there is no interference between the welding lines 2-2 and 1-2, the robot 1 is deleted from the buffer and the welding line 1-2
Welding is started (see FIG. 19 (e)). Therefore, the buffer is empty at this point.

The above process is repeated until all the welding lines are welded, and the order of welding and the sharing are set as the welding order and sharing of the actual work in the simulation (S33). In this way, it is possible to determine the work order and work assignment that minimize the total work time. Also, in order to make the total work time extremely short, it is not necessary to repeat the simulation of the work order and work assignment of each robot, and to repeat trial and error regarding the work assignment and work order, so it is necessary to decide in a short time. You can In the second embodiment, the interference area on the two-dimensional plane is obtained by using simulation, but in actual use, the interference area is obtained by using the three-dimensional robot position and posture. Maybe,
Further, the robot may be actually operated to sequentially determine the work order and work sharing. In the second embodiment, the criterion for determining the next welding line is the one with the shortest distance, but in actual use, another criterion, such as the farthest welding line, may be used.

[0019]

Since the interference avoidance method for a plurality of robots according to the first aspect of the invention is configured as described above, it is possible to obtain an interference area in a continuous area and update the interference area every certain time. , Mutual interference between robots can be reliably avoided, and the robot stop time can be greatly reduced. In addition, since the occupied area and the like are expressed by a shape having a relatively small number of elements, the load on the memory and the CPU of the computer that performs the determination calculation is much smaller than that of the conventional method using blocks. As a result, it is possible to obtain optimal work efficiency with multiple robots. Further, in the work order / work sharing determination method for a plurality of robots according to the second aspect of the invention, the work order and work sharing can be determined such that the total work time is the shortest. Furthermore, in order to reduce this total work time very much,
It is possible to repeat work sharing by repeating simulations, work sharing,
Since it is not necessary to repeat trial and error regarding the work order, it can be decided in a short time.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic flow of an interference avoidance method for a plurality of robots according to an embodiment (first embodiment) of the first invention.

FIG. 2 shows an example A of an apparatus to which the above interference avoidance method can be applied.
2 is a block diagram showing a schematic configuration in 1. FIG.

FIG. 3 is a diagram showing a schematic operation flow of the interference avoidance device A1.

FIG. 4 is a conceptual diagram of a reserved area.

FIG. 5 is a conceptual diagram showing the overall configuration of a robot.

FIG. 6 is a conceptual diagram showing an envelope shape of a robot.

FIG. 7 is a diagram showing a coordinate system of a reserved area.

FIG. 8 is a flowchart showing a detailed operation procedure of the interference avoidance device A1.

FIG. 9 is a block diagram showing a schematic configuration of another example A2 of an apparatus to which the interference avoidance method can be applied.

FIG. 10 is a diagram showing a schematic flow of a work order / work sharing determination method for a plurality of robots according to an embodiment (second embodiment) of the second invention.

FIG. 11 is a conceptual diagram of a plurality of robots.

FIG. 12 is a diagram showing a detailed flow of a welding order / welding share determination method for a multiple welding robot.

FIG. 13 is an explanatory diagram showing an example of determining a welding order when the robots having the priority orders 1 and 2 are adjacent to each other.

FIG. 14 is an explanatory diagram showing an example in which a robot moves between welding lines.

FIG. 15 is an explanatory diagram showing an example of changes in the interference region at times t and t + T.

FIG. 16 is a block diagram showing a relationship among a welding simulator, a welding waiting robot buffer, and a welding determination mechanism.

FIG. 17 is an explanatory view showing a work on which welding lines are arranged.

FIG. 18 is a diagram showing an operation time chart of each robot with respect to a simulation time in the work and a registration state in a buffer.

FIG. 19 is an explanatory diagram showing a state during simulation.

[Explanation of symbols]

 S1 ... Priority setting step S2 ... Occupied area calculation step S3 ... Occupied area overlap determination step S6 ... Other robot occupied area release step S7 ... One robot operation start step S10 ... One robot's first work selection step S11 ... Priority setting step S12 ... Occupied area calculation step S13 ... Occupied area overlap determination step S16 ... Occupied area release step of the other robot S17 ... Robot start operation step in standby S18 ... Work order / work allocation decision step

Claims (3)

[Claims] 1. In a method for avoiding mutual interference between a plurality of robots having a common movement space, a priority order of motions of each robot is set, and a planned passage area of the robots according to motions of each robot within a predetermined time or The occupied area, which is the expanded area including it, is sequentially calculated, and it is determined whether or not there is overlap between the calculated occupied areas. If there is overlap,
While waiting for one robot with the lower priority, the other robot with the higher priority is operated, and the occupation area of the other robot is released in sequence for the parts that have already completed their operations during the operation of the other robot. An interference avoidance method for a plurality of robots, wherein the operation of one of the robots is started after the overlap is eliminated based on the change of the occupied area of the other robot. 2. A method of determining a work order / work sharing of a plurality of robots having a common movement space, wherein a first work of a certain robot is selected in advance, and a priority order of motions of the robots is set. When the robot's planned passage area or the occupied area, which is an expanded area including it, is sequentially calculated by the operation of each robot within a predetermined time, and it is determined whether or not there is overlap between the calculated occupied areas, and there is no overlap. Is
From among the unselected tasks within the motion range of each robot, one task is sequentially selected for each robot based on the distance between the unselected task and the task selected immediately before and the above priority, Each robot is operated for the selected work, and when there is an overlap, two or more robots with lower priority are placed on standby, and an unselected robot within the operation range of the other robot with the highest priority is selected. Among the works, one work is selected based on the distance between the unselected work and the work selected immediately before, and the other robot is operated for the selected work, and the other robot is operated. The occupying area of the other robot is sequentially released for the part that has already finished moving during the operation of the other robot, and based on the change of the occupying area of the other robot, after the overlap disappears, From the unselected tasks within the robot's operation range, one task was sequentially selected for each robot based on the distance between the unselected task and the task selected immediately before and the priority. The work order and work sharing of a plurality of robots characterized in that the work order and work sharing of each robot are determined by sequentially operating the robots that have been on standby for the selected work. How to decide. 3. The method for determining the work order / work share of a plurality of robots according to claim 2, wherein the work order is the welding order and the work share is the welding share.