JP2023172561A - Work system and work method - Google Patents

Abstract

To perform appropriate work sharing even when an error is generated in a shape or a position of a workpiece as a work object.SOLUTION: A work system for executing a work of welding or joining an object member includes: a measuring robot for measuring a shape of the object member; a plurality of work robots for executing the work relative to the object member; a work route generating part for generating a work route including work position information based on the measured data measured by the measuring robot; and a work distribution part for dividing the work route into a plurality of routes, and distributing the work routes after divided into the plurality of work robots.SELECTED DRAWING: Figure 1

Description

The present invention relates to a technique for performing operations such as welding, adhesion, and other processing on target members.

Techniques for welding workpieces using multiple welding robots have been proposed in the past, and Patent Document 1 discloses that a plurality of welding robots are set in advance on the workpiece so that the time required for the robot to reach the work point is the shortest possible time. A technology has been disclosed that allocates work points to multiple robots and efficiently shares the work among the multiple robots.

JP 8-36409

In actual work sites, errors occur in the shape and position of the workpieces that have been set in advance, so the technology for determining work assignments described in Patent Document 1 causes deformation of the shape and positional deviation of the workpieces. In some cases, work could not be divided appropriately among multiple robots.

The present invention has been made in view of this background, and provides a work system or a work system that allows appropriate division of work even when an error occurs in the shape or position of the workpiece. The purpose is to provide a method.

The main invention of the present invention for solving the above problems is a work system that performs a work of welding or joining target members, which includes a measuring robot that measures the shape of the target member, and a measuring robot that performs the work on the target member. a plurality of work robots that execute a plurality of work robots, a work route generation unit that generates a work route including work position information based on measurement data measured by the measurement robot, and a work route generation unit that divides the work route into a plurality of parts, and divides the work route into a plurality of parts, and a work distribution unit that distributes the work route to the plurality of work robots.

Other problems disclosed in the present application and methods for solving the problems will be made clear by the section of the embodiments of the invention and the drawings.

According to the present invention, it is possible to provide a welding system and a welding method that can suppress deterioration of welding accuracy.

1 is a diagram showing an example of the overall configuration of a welding system 100 according to the present embodiment. FIG. 2 is a diagram showing how a welding target member is measured using the welding system 100 of the present embodiment. FIG. 2 is a diagram showing how welding target members are welded using the welding system 100 of the present embodiment. It is a figure showing the example of composition of the measurement control part 24 and other hardware concerning this embodiment. It is a diagram showing an example of the functional configuration of a measurement control section 24 according to the present embodiment. FIG. 3 is a diagram showing an example of condition data stored by a torch position/angle condition storage unit according to the present embodiment. It is a figure which shows an example of the control flowchart of the measurement control part 24 based on this embodiment. It is a figure which shows an example of the boundary line between the members to be welded which are the planned welding parts by the gap measurement part based on this embodiment. FIG. 3 is a diagram showing an example of a plurality of cylindrical arcs defined around a planned welding location by the gap measuring section according to the present embodiment. FIG. 6 is a diagram illustrating an example in which the gap measurement unit according to the present embodiment estimates a gap distance from point cloud data. FIG. 6 is a diagram showing how welding is performed when the gap distance is smaller than a predetermined value in this embodiment. FIG. 6 is a diagram showing how welding is performed when the gap distance is larger than a predetermined value in this embodiment. FIG. 6 is a diagram illustrating an example in which the gap measurement unit according to the present embodiment estimates a gap distance from point cloud data. FIG. 6 is a diagram showing how welding is performed when the gap distance is smaller than a predetermined value in this embodiment. FIG. 6 is a diagram showing how welding is performed when the gap distance is larger than a predetermined value in this embodiment. FIG. 6 is a diagram illustrating an example in which the gap measurement unit according to the present embodiment estimates a gap distance from point cloud data. FIG. 6 is a diagram showing how welding is performed when the gap distance is smaller than a predetermined value in this embodiment. FIG. 6 is a diagram showing how welding is performed when the gap distance is larger than a predetermined value in this embodiment. It is a diagram showing an example of the functional configuration of a work sharing section 34 according to the present embodiment. It is a figure showing an example of welding priority stored by a welding priority storage part concerning this embodiment. FIG. 3 is a diagram illustrating an example of distribution conditions stored by a distribution condition storage unit according to the present embodiment. It is a figure which shows an example of the control flowchart of the work allotment part 34 based on this embodiment. It is a figure showing an example of the distribution result of welding work by work distribution part 34 concerning this embodiment. 7 is a diagram illustrating another example of the distribution result of welding work by the work distribution unit 34 according to the present embodiment. FIG. 7 is a diagram illustrating another example of the distribution result of welding work by the work distribution unit 34 according to the present embodiment. FIG.

The contents of the embodiments of the present invention will be listed and explained. The present invention includes, for example, the following configuration.

[Item 1]
A work system that performs work to weld or join target members,
a measuring robot that measures the shape of the target member;
a plurality of work robots that perform the work on the target member;
a work route generation unit that generates a work route including work position information based on measurement data measured by the measurement robot;
A work system comprising: a work distribution unit that divides the work route into a plurality of parts and distributes the divided work route to the plurality of work robots.
[Item 2]
In the work system described in item 1,
A work system, wherein the measurement data measured by the measurement robot includes a gap distance between the target members.
[Item 3]
In the work system described in item 2,
In the work system, the divided work route generated by the work distribution unit is a work route in which the work route with the shorter gap distance is worked on before the work route with the longer gap distance.
[Item 4]
In the work system described in any one of items 1 to 3,
comprising a robot characteristic storage unit that stores characteristics of the plurality of work robots,
The work distribution unit distributes the work path to the work robots so that the operating distance or operation time of each work robot, which is estimated based on the characteristics, is approximately uniform among the plurality of work robots. Distribute, work system.
[Item 5]
In the work system described in any one of items 1 to 4,
comprising a work history storage unit that stores history information of the working distance or working time of each of the plurality of working robots,
The work distribution unit is configured to distribute the work route to the work robots based on the history information so that a difference in cumulative values of the movement distance or the movement time is reduced.
[Item 6]
In the work system described in any one of items 1 to 5,
A work system in which a coordinate system of the measurement robot and a coordinate system of the work robot are the same coordinate system.
[Item 7]
In the work system described in any one of items 1 to 6,
The work system wherein the measurement data measured by the measurement robot is three-dimensional point group data of the target member.
[Item 8]
A work method using a system for performing work of welding or joining target members, the method comprising:
Measuring the shape of the target member using one or more measuring robots;
generating a work route including information on work positions based on measurement data measured by the measurement robot;
A working method comprising the steps of dividing the working route into a plurality of parts and distributing the divided working route to the plurality of working robots.

<Details of Embodiment 1>
A specific example of a welding system 100 according to an embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims. In the following description, the same or similar elements are given the same or similar reference numerals and names in the accompanying drawings, and overlapping description of the same or similar elements may be omitted in the description of each embodiment. Furthermore, features shown in each embodiment can be applied to other embodiments as long as they do not contradict each other.

FIG. 1 is a diagram showing an example of a welding system 100 of this embodiment. As shown in FIG. 1, the welding inspection system 100 of this embodiment includes an input/output unit 1, a controller 3, one or more measurement robots 20, and one or more measurement robot control units 23. , a measurement control section 24, a plurality of welding robots 30, a plurality of welding robot control sections 33, and a work distribution section . The measuring robot 20 acquires information regarding the shape of the welding object 2 using the sensor 21 . The measurement robot control unit 23 is a control unit that is connected to the measurement robot 20 so as to be able to communicate with each other by wire or wirelessly, and controls the measurement operation of the measurement robot 20 and obtains measurement results. If there are a plurality of measurement robots, the measurement robot control unit 23 is provided for each measurement robot. The measurement control unit 24 is connected to each measurement robot control unit 23 so as to be able to communicate with each other by wire or wirelessly, and indicates the welding position for the measurement object 2 based on the measurement results obtained from each measurement robot control unit 23. This is a control unit that generates a work path (welding path). Here, the measurement control unit 24 does not necessarily have to be an independent device from the measurement robot control unit 23, and the measurement control unit 24 and the measurement robot control unit 23 may be configured in one and the same device. Also good.

The work distribution section 34 is connected to the measurement control section 24 by wire or wirelessly so as to be able to communicate with each other, and acquires information such as work routes from the measurement control section 24 . Further, the work distribution unit 34 allocates the work of welding the work path, and transmits information regarding the welding work to be allocated to each welding robot control unit 33 to the welding robot control unit 33.
The welding robot control section 33 is connected to the work distribution section 34 in a wired or wireless manner so as to be able to communicate with each other, and controls the welding robot based on the information regarding the welding work received from the work distribution section 34 . Further, the welding robot control section 33 can also accommodate a plurality of welding robots 30 corresponding to the plurality of welding robots 30. The welding robot 30 is connected to a welding robot control section 33 by wire or wirelessly so as to be able to communicate with each other, and performs welding work on the welding object 2 based on control commands received from the welding robot control section 33. Execute. Here, the work distribution section 34 does not necessarily have to be an independent device from the welding robot control section 33, and the work distribution section 34 and the welding robot control section 33 may be configured as one and the same device. Also good.

The input/output unit 1 is an output device that is connected to the measurement control unit 24 and the work distribution unit 34 so as to be able to communicate with each other by wire or wirelessly, and displays data stored in the storage units of the measurement control unit 24 and the work distribution unit 34. (for example, a display) and an information input device (for example, a keyboard, a mouse, a touch panel, etc.) for inputting data stored in the storage unit. The controller 3 is connected to the measurement control unit 24 and the work distribution unit 34 so as to be able to communicate with each other by wire or wirelessly, and includes an input unit for inputting instructions for starting and stopping the operation of the measurement robot 20 and the welding robot 30. .

FIG. 2 is a diagram showing how a three-dimensional shape of a welding target member is measured using a plurality of measuring robots 20 of the welding system 100 and a working path 200 is generated. The measurement robot 20 has an arm 21 and a sensor 22 mounted on the tip of the arm 21. Based on the three-dimensional CAD data of the welding object 2 obtained in advance, the measurement range is set as a range including the parts where the two welding objects 201 and 202, which are the two members to be welded, are close to each other. The measuring robot 20 uses a sensor 22 provided on the arm 21 of the measuring robot 2 to acquire point cloud data of the surface shape of the measurement range. Furthermore, a work route 200 for welding work is generated based on this point cloud data.

FIG. 3 is a diagram showing how welding is performed on the work path 200 using the plurality of welding robots 30 of the welding system 100. The welding robot 30 includes at least an arm 31 and a welding torch 32 mounted on the tip of the arm 31. As shown in FIG. 3, when the welding object 2 has a complicated structure, it is difficult for one welding robot to weld all positions on the work path 200, so multiple welding robots are required. The welding work will be divided and carried out. Since the welding work on the work path 200 is distributed to each welding robot by the work distribution unit 34, the welding robot 30 can set the target position of the welding torch 32 based on the welding work assigned to it. The operation of the arm 31 is controlled to achieve the target angle, and the welding work is executed.

<Hardware>
FIG. 4 is a diagram showing the hardware configuration of the measurement control section 24, the work distribution section 34, the measurement robot control section 23, or the welding robot control section 33. The measurement control unit 24, the work distribution unit 34, the measurement robot control unit 23, or the welding robot control unit 33 may be a general-purpose computer such as a personal computer, or may be logically realized by cloud computing. It's okay. Note that the illustrated configuration is an example, and other configurations may be used. For example, some of the functions provided in the processor 10 may be executed by a server or another terminal external to the measurement control section 24, the work distribution section 34, the measurement robot control section 23, or the welding robot control section 33.

The measurement control section 24, the work distribution section 34, the measurement robot control section 23, or the welding robot control section 33 includes at least a processor 10, a memory 11, a storage 12, a transmission/reception section 13, an input/output section 14, etc. are electrically connected to each other through a bus 15.

The processor 10 controls the operation of the measurement control unit 24 and the like in which it is installed, controls the transmission and reception of data, etc. to and from devices connected by wire or wirelessly via the transmission/reception unit 13, and executes and authenticates applications. This is a calculation device that performs information processing necessary for processing. For example, the processor 10 is a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a CPU and a GPU, and executes programs for this system stored in the storage 12 and developed in the memory 11. Performs each information processing.

The memory 11 includes a main memory made up of a volatile storage device such as a DRAM (Dynamic Random Access Memory), and an auxiliary memory made up of a non-volatile storage device such as a flash memory or an HDD (Hard Disc Drive). . The memory 11 is used as a work area of the processor 10, and also stores a BIOS (Basic Input/Output System) that is executed when the measurement control unit 24 and the like in which it is installed is started, various setting information, and the like.

The storage 12 stores various programs such as application programs. A database storing data used for each process may be constructed in the storage 12.

The transmitting/receiving unit 13 connects to a device that is communicably connected to the device in which it is mounted, and transmits and receives data and the like according to instructions from the processor. Note that the transmitter/receiver 13 is configured by wire or wirelessly, and in the case of wireless, it may be configured by, for example, a short-range communication interface such as WiFi, Bluetooth (registered trademark), or BLE (Bluetooth Low Energy). .

The bus 15 is commonly connected to each of the above elements and transmits, for example, address signals, data signals, and various control signals.

<Measurement robot 20>
Returning to FIGS. 1 and 2, the working robot 2 according to this embodiment will be described. As described above, the measurement robot 20 includes the arm 21 and the sensor 22. Note that the illustrated configuration is an example, and the present invention is not limited to this configuration.

The operation of the arm 21 is controlled by a measuring robot control section 23 based on a three-dimensional robot coordinate system. Further, the operation of the arm 21 may be controlled by the controller 3.

The sensor 22 performs sensing of the welding target members 201 and 202 based on a three-dimensional sensor coordinate system. The sensor 22 is, for example, a laser sensor that operates as a three-dimensional scanner, and acquires three-dimensional point group data 50 of the members to be welded 201 and 202 including the position to be welded by sensing. In the three-dimensional model data 50, for example, each point data has coordinate information of the sensor coordinate system, and the shape of the object to be inspected can be grasped by the point group. Note that the sensor 22 is not limited to a laser sensor, and may be an image sensor using a stereo system, for example, or may be a sensor independent of the measurement robot, and may be a sensor in a three-dimensional sensor coordinate system. Any information from which coordinate information can be obtained may be used. Further, in order to make the explanation more specific, a configuration using three-dimensional point group data as the three-dimensional model data 50 will be described below as an example.

Note that by performing a predetermined calibration before work and associating the robot coordinate system and the sensor coordinate system with each other, for example, the user can specify the position (coordinates) based on the sensor coordinate system, so that the arm 21 and sensor 22 can The configuration may be such that the operation is controlled based on the position. In addition, when the shape of the welding object 2 is complex or the planned welding position is three-dimensional, a plurality of measuring robots 20 may be used to measure the three-dimensional welding object members 201 and 202 of the welding object 2. Point cloud data 50 is acquired, and the measurement control unit 24 generates a work route 200 based on the three-dimensional point cloud data 50. By defining the robot coordinate systems of multiple measurement robots as the same coordinate system, the three-dimensional point cloud data acquired by each measurement robot can be integrated in a short time, and the entire part to be welded can be integrated. 3D point cloud data can be obtained with high precision and in a short time.

<Welding robot 3>
A welding robot 3 according to this embodiment will be explained using FIGS. 1 and 3. As described above, the welding robot 2 includes the arm 31 and the welding torch 32. Note that the illustrated configuration is an example, and the present invention is not limited to this configuration.

The operation of the arm 31 is controlled by a welding robot control section 33 based on a three-dimensional robot coordinate system. Further, the operation of the arm 31 may be controlled by the controller 4.

The welding torch 32 performs welding work based on a work path 200 set in the vicinity of the welding target members 201 and 202 based on a three-dimensional torch coordinate system. The welding torch 32 is a tool used in fusion welding methods such as arc welding, laser welding, electron beam welding, and plasma arc welding, and the welding torch outputs an arc, laser, beam, etc. that melts the workpiece to be welded. Then, the members to be welded 201 and 202 are welded. Note that the welding torch may be a discharge part for a filler material (adhesive) used in soldering such as brazing, or a discharge part for a sealant or an adhesive.

Note that a predetermined calibration is performed before the work, and the robot coordinate systems and torch coordinate systems of the measurement robot 20 and welding robot 30 are associated with each other, and for example, the user specifies the position (coordinates) based on the torch coordinate system. Accordingly, the configuration may be such that the operation of the arm 31 and the welding torch 32 is controlled based on the corresponding positions. Furthermore, by defining the robot coordinate systems of a plurality of welding robots as the same coordinate system as the robot coordinate system of the measuring robot, welding work can be performed in a short time on the work paths distributed from the work distribution section. be able to.

<Functions of the measurement robot control unit 23>
If there are a plurality of measurement robots, the measurement robot control unit 23 is provided for each measurement robot. The measurement robot control unit 23 also receives measurement conditions related to the measurement operation (including the position and measurement direction of the sensor 22) from the measurement control unit 24, generates an operation command that satisfies the measurement conditions, and connects the unit for communication. The operation command is transmitted to the measuring robot 20 to control the measuring operation by the measuring robot 20, and the three-dimensional point group data 50 measured by the measuring robot 20 is acquired. The measurement robot control unit 23 transmits the acquired three-dimensional point group data 50 to the measurement control unit 24. Here, the measurement robot control section 23 does not necessarily need to be provided for each measurement robot, and if the computing performance of the hardware is sufficiently high, one measurement robot control section 23 can control multiple robots. It may also be configured to control a measuring robot.

<Function of measurement control unit 24>
FIG. 5 is a block diagram illustrating functions implemented in the measurement control section 24. As shown in FIG. In this embodiment, the measurement control section 24 includes a processing section 2410 and a storage section 2420. The processing section 2410 includes a measurement condition determination section 2411, a point cloud data acquisition section 2412, a gap measurement section 2413, a welding torch position/angle determination section 2414, and a work path generation section 2415. The storage unit 2420 of the measurement control unit 24 also includes a measurement condition storage unit 2421, a three-dimensional CAD data storage unit 2422, a measurement point group data storage unit 2423, a torch position/angle condition storage unit 2424, a gap storage unit 2425, and a working route. It has a storage section 2426.

The measurement method determining unit 2411 determines the method based on the measurement conditions stored in the measurement condition storage unit 2421 and the three-dimensional CAD data (three-dimensional shape data) of the welding object 2 stored in the three-dimensional CAD data storage unit 2422. , determines a measurement method including the position and measurement direction (orientation of the sensor 22 ) of the sensor 22 that performs the measurement, and transmits the measurement conditions to the measurement robot control unit 23 . The three-dimensional CAD data includes information on a predetermined welding location on the welding object 2, and the measurement conditions include information on the position and measurement direction of the sensor 22 with respect to the welding location. ing. Furthermore, when a plurality of measurement robots 20 share the measurement work, the measurement condition storage unit 2421 includes information regarding the plurality of measurement robots 20 as measurement conditions, and the measurement condition determination unit 2411 As well as assigning a measurement range to each of the measurement robots 20 on the stand, measurement conditions including the position and measurement direction (orientation of the sensor 22) of the sensor 22 of each measurement robot 22 are determined. The measurement conditions are transmitted to the corresponding measurement robot control unit 23.

The point cloud data acquisition unit 2412 generates a three-dimensional point cloud of the welding object 2 including the boundary position (planned welding location) between the welding target members 201 and 202 acquired by the measuring robot 20 via the measuring robot control unit 23. Get data. The acquired three-dimensional point group data is, for example, three-dimensional coordinate information data based on the sensor coordinate system, and is stored in the measurement point group data storage unit 2423.

The gap measurement unit 2413 measures the distance (gap distance) between the welding target members 201 and 202 at the welding location set in the 3D CAD data based on the acquired 3D point cloud data and 3D CAD data. do. The measured gap distance is recorded in the gap storage section 2424. Here, the distance (gap distance) between the members to be welded 201 and 202 is the distance between the gaps between the parts to be welded 201 and the members to be welded 202 in the vicinity of the welding target part. It can be estimated as the distance between two points where the straight line distance is the shortest among the straight line distances connecting the point group of and the point group of the welding target member 202, but it is not necessarily limited to this. Further, the gaps are estimated at multiple positions of the planned welding location. A specific method for estimating the gap will be described later.

The welding torch position/angle determining unit 2414 performs gap measurement according to the measured gap distance, information on each shape type of T type, J type, and overlap type, and information in the torch position/angle condition storage unit 2424. Determine the position and angle of the welding torch relative to the workpiece to be welded. In addition, if the gap distance exceeds a predetermined value (for example, a predetermined threshold value), it is determined that welding is not possible, and an error notification is sent via the input/output unit 14 to the effect that welding should not be performed. Prohibit execution of work. Details of how to determine the position and angle of the welding torch for each of the T-shape, J-shape, and overlap-shape types will be described later.

The work route generation unit 2415 generates a work route based on the information on the position and angle of the welding torch with respect to the welding target member determined by the welding torch position/angle determination unit 2414. The generated work route is recorded in the work route storage section 2426. Preferably, the generated work route is defined in a coordinate system based on the same measurement target member as the coordinate system of the measurement robot.

FIG. 6 is a diagram showing an example of information recorded in the torch position/angle condition storage section 2424. The torch position/angle condition storage unit 2424 stores the measured gap distance, information on the position and angle of the welding torch corresponding to each shape type of T type, J type, and overlap type, and information on welding suitability. has been done. In the overlap type, when the gap distance n is smaller than the first threshold value (Th1), the welding torch position and welding torch angle are not changed from the predetermined position and predetermined angle (θ1), respectively, and the gap distance is If n is larger than the first threshold value (Th1) and smaller than the second threshold value (Th2), the position of the welding torch is shifted from the predetermined position to the positive side in the Z direction (the torch angle is set to a predetermined value). If the gap distance n is larger than the second threshold value (Th2), the gap distance is too large and welding is rejected.

Next, in the T type, if the gap distance n is smaller than the third threshold value (Th3), the welding torch position is set to the member boundary position, and the welding torch angle is set to a predetermined angle (θ2). If the gap distance n is larger than the third threshold value (Th3) and smaller than the fourth threshold value (Th4), the torch position is shifted from the member boundary position to the positive side in the Z direction. (the torch angle is not changed from the predetermined angle (θ2)), and if the gap distance n is larger than the fourth threshold value (Th4), the gap distance is too large and welding is rejected.

Next, in the J type, when the gap distance n is smaller than the fifth threshold value (Th5), the welding torch position and welding torch angle are not changed from the predetermined position and predetermined angle (θ3), respectively. When the gap distance n is larger than the fifth threshold value (Th5) and smaller than the sixth threshold value (Th6), the torch position is shifted from the predetermined position to the negative side in the X direction, and the torch angle is set to the predetermined value. Do not change the angle. When the gap distance n is larger than the sixth threshold value (Th6) and smaller than the seventh threshold value (Th7), the torch position is shifted from the predetermined position to the negative side in the X direction, and the torch angle is set to the predetermined value. The angle is decreased from the angle (θ3) to an angle (θ3') that is nearly parallel to the lower member. If the gap distance n is larger than the seventh threshold value (Th7), the gap distance is too large and welding is rejected.

<Control flow>
FIG. 7 is a diagram showing a control flow of the measurement control section 24 in this embodiment. First, the measurement condition determination unit 2411 determines measurement conditions, etc. (step 101). Next, the point cloud data acquisition unit 2412 acquires three-dimensional point cloud data (step 102). In this step, the measurement robot 20 is controlled to measure the welding object 2 based on the measurement conditions determined in step 101 described above, and three-dimensional point cloud data of the surface shape of the welding object including the planned welding location is obtained. get.

Next, gap measurement is performed by the gap measurement unit 2413 (step 103). In this step, the gap measurement unit 2413 measures the distance (gap distance) between the welding target members 201 and 202 at the welding planned location based on the measured three-dimensional point group data. FIG. 8 shows a boundary line between members 201 and 202 to be welded when performing overlap type welding. The gap measurement unit 2413 generates a plurality of circular arcs surrounding the welding location based on the information of the welding location preset in the three-dimensional CAD data, and generates a cylindrical space around the welding location. . FIG. 9 shows an example of a plurality of cylindrical arcs defined around the work path in this process. The gap measurement unit 2413 extracts two-dimensional point cloud data within the cylinder (inside the circular arc) on each cross-sectional plane defined by this circular arc from the three-dimensional point cloud data acquired by the point cloud data acquisition unit 2412. The gap measurement unit 2413 calculates the gap distance between the welding target member 201 and the welding target member 202 based on two-dimensional point cloud data.

Next, the welding torch position/angle determination unit 2414 determines the welding position and angle of the welding torch on each cross-sectional plane defined by the aforementioned circular arcs (step 104). In this step, the welding torch position/angle determining unit 2414 uses information on the torch position and angle corresponding to the gap distance and shape type, and information on welding suitability, which are stored in the torch position/angle condition storage unit 2424. , determines the position of the welding torch and the angle of the welding torch, determines the suitability of welding, and notifies the user of the determination result of suitability of welding via the controller 3 or the input/output unit 1.

Next, the work route generation unit 2415 generates a work route (step 105). In this step, the work path generation unit 105 defines the welding torch movement route and angle based on the welding torch position and welding torch angle determined for each cross-sectional plane defined by a plurality of circular arcs. Generate a work route. Here, the work route can also be defined as a movement route defined only by the position of the welding torch. Here, an example is shown in which the position and angle of the welding torch are changed according to the size of the gap distance measured by the gap measurement section, but the working route is determined using three-dimensional point cloud data acquired by the point cloud data acquisition section 2412. It is also possible to detect the boundary line between the welding target member 201 and the welding target member 202 and generate the boundary line as a work route.

<Overlap type>
FIG. 10(a) shows the positions of the welding target member 201, the welding target member 202, and the sensor 22 on the cross-sectional plane defined by the circular arc 220 when measuring the welding target members 201 and 202 of the overlap type shape type. Show relationships. FIGS. 10(b) and 10(c) show point cloud data ( 2D). The gap measurement unit 2413 calculates a point group indicating the lowest part (end) of the welding target member 201 and the surface shape of the welding target member 202 based on two-dimensional point cloud data as shown in FIG. 10(b). By calculating the distance to the indicated point group, the gap distance between the welding target members 201 and 202 is obtained. As an example, the gap distance in the overlap type (a shape in which the members to be welded are arranged so as to overlap each other) shown in Fig. 10 is as shown in Fig. 10b. A pair of points of the member 201 and a point group of the member to be welded 202, and can be defined as the distance between the pair of points where the straight distance between the points is the shortest. However, it does not necessarily have to be the distance between the point groups where the straight line distance is the shortest, but is defined as the distance between point groups that are close to each other in a pair of point groups of the welding target member 201 and the point group of the welding target member 202 You may do so.

Alternatively, as another method of calculating the gap distance, the gap measurement unit 103 calculates the coordinates in the Z-axis direction of a point group indicating the upper surface of the welding target member 201 and the welding target member 202, as shown in FIG. 10(c). It is also possible to calculate the distance between the upper surfaces from the coordinates in the Z-axis direction of the point group indicating the upper surfaces, and then obtain a value obtained by subtracting the thickness of the member 201 to be welded from this distance as the gap distance.

FIG. 11 is a diagram showing the welding position and the angle of the welding torch when the gap distance between the members is less than the first threshold value (for example, 1 mm). As shown in Fig. 11, when the gap distance between the members is less than a predetermined distance (for example, 1 mm), the welding torch is shifted from the member boundary position in the X-axis direction by a predetermined distance (several millimeters) in the X-axis direction. is the welding position, and the angle of the welding torch with respect to the plane of the member 202 to be welded is determined to be a predetermined angle (θ ₁ ).

Figure 12 shows the welding position and angle of the welding torch when the gap distance (n mm) between the members is greater than the first threshold (for example, 1 mm) and less than the second threshold. FIG. As shown in FIG. 13, when the gap distance between the members is larger than the first threshold (for example, 1 mm) and less than the second threshold, the welding torch moves toward the welding target member 202 in the Z-axis direction. The welding position is defined as a position shifted from the surface position by the gap distance (n millimeters) in the Z-axis direction from the boundary position of the member, and the welding torch is tilted at a predetermined angle (θ ₁ ) from the member plane of the member to be welded 202. determined (i.e., no change in angle). In this way, by shifting the welding torch from the boundary position in the Z-axis direction by the gap distance (n millimeters), the arc etc. discharged from the welding torch will follow the upper workpiece to be welded and will be connected to the lower workpiece. Can be joined.

<T type>
FIG. 13A shows the positional relationship on the cross-sectional plane defined by the circular arc 220 when measuring the T-shaped members 201 and 202 to be welded. FIG. 13(b) shows point group data (two-dimensional) on a cross-sectional plane defined by the circular arc 220, extracted from the three-dimensional point group data acquired in the positional relationship shown in FIG. 13(a). The gap measuring unit 2413 calculates a point group indicating the lowest part (end) of the welding target member 201 and the surface shape of the welding target member 202 based on two-dimensional point cloud data as shown in FIG. 13(b). By calculating the distance to the indicated point group, the gap distance between the welding target members 201 and 202 is obtained. The gap distance in the T-shape (a shape in which the members to be welded are substantially perpendicular to each other) shown in FIG. It is a pair of point clouds of the welding target member 202, and can be defined as the distance between the pair of point clouds where the straight line distance between the point clouds is the shortest. However, it does not necessarily have to be the distance between the point groups where the straight line distance is the shortest, but is defined as the distance between point groups that are close to each other in a pair of point groups of the welding target member 201 and the point group of the welding target member 202 You may do so.

FIG. 14 is a diagram showing the welding position and the angle of the welding torch when the gap distance between the members is less than the third threshold (for example, 0.5 mm). As shown in FIG. 14, when the gap distance between the members is less than a predetermined distance (for example, 0.5 mm), the welding torch sets the welding position at the member boundary position, and the welding torch angle is set at a predetermined angle from the member plane of the welding target member 202. The angle (θ ₂ ) is determined to be an inclined angle.

Figure 15 shows the welding position and angle of the welding torch when the gap distance (n millimeters) between members is greater than the third threshold (for example, 0.5 mm) and less than the fourth threshold. FIG. As shown in FIG. 15, when the gap distance between the members is greater than the third threshold (for example, 0.5 mm) and less than the fourth threshold, the welding torch moves toward the welding target member 202 in the Z-axis direction. The welding position is a position shifted by the gap distance (n millimeters) from the boundary position of the member in the Z-axis direction from the surface position of the member, and the angle of the welding torch is an angle tilted by a predetermined angle (θ ₂ ) from the member plane of the member to be welded 202. (i.e., no change in angle). In this way, by shifting the welding torch by the gap distance (n millimeters) from the boundary position in the Z-axis direction, the arc etc. discharged from the welding torch will follow the upper welding target member, and the lower welding target member It can be joined with

<J type>
FIG. 16(a) shows the positional relationship on the cross-sectional plane defined by the circular arc 220 when measuring the J-shaped members 201 and 202 to be welded. FIG. 16(b) shows point group data (two-dimensional) on a cross-sectional plane defined by the circular arc 220, extracted from the three-dimensional point group data acquired in the positional relationship shown in FIG. 16(a). As shown in FIG. 16(b), the gap measurement unit 2413 estimates the radius of curvature of the curved portion based on the point cloud data of the bent curved portion of the welding target member 201, or calculates the radius of curvature based on information input by the user. get. The gap distance between the lower side of the curvature portion (the welding target member 202 side) and the welding target member 202 is estimated based on the estimated or acquired curvature radius. The gap distance in the J-shape (a shape in which the welding target member 201 having a bent curvature portion and the plate-shaped welding target member 202 are welded at the curvature portion) shown in FIG. 16 is, for example, as shown in FIG. 16b. , the distance between the end of the bent curvature part of the welding target member 201 that is close to the welding target member 202 and the end of the welding target member 202, and the distance between the ends where the straight line distance is the shortest. Can be defined by distance. However, it does not necessarily have to be the shortest distance, and may be defined as the distance between the ends of the welding target member 201 and the welding target member 202 at positions close to each other.

FIG. 17 is a diagram showing the welding position and the angle of the welding torch when the gap distance between the members is less than the fifth threshold (for example, 1 mm). As shown in FIG. 17, when the gap distance between the members is less than a predetermined distance (for example, 1 mm), the welding torch is moved from the intersection of the extension line of the side surface of the upper welding target member 201 and the lower welding target member 202. A position shifted by a predetermined distance (for example, 1 mm) in the negative direction of the X-axis is defined as a welding position, and the angle of the welding torch is determined to be inclined by a predetermined angle (θ ₃ ) from the plane of the member 202 to be welded. In this way, by setting the welding position at a position shifted by a predetermined distance in the negative direction of the X-axis from the intersection of the extension line of the side surface of the upper welding target member 201 and the lower welding target member 202, the welding torch discharges the welding torch. The arc and the like can more easily hit the upper and lower members to be welded, and the members to be welded can be joined more reliably.

FIG. 18 is a diagram showing the welding position and the angle of the welding torch when the gap distance (n millimeters) between members is larger than the fifth threshold (for example, 1 millimeter). The angle of the welding torch is such that if the gap distance (n mm) between the parts is greater than the fifth threshold (e.g. 1 mm) and less than the sixth threshold (e.g. 2 mm), the welding torch The angle is determined to be a predetermined angle (θ ₃ ) (that is, the angle is not changed). If the gap distance (n mm) between the parts is greater than the sixth threshold (e.g. 2 mm) and less than the seventh threshold (e.g. 3 mm), the angle of the welding torch should be reduced. θ _3′ , which is smaller than θ _3, is determined as the angle of the welding torch (that is, the lower welding target member). In this way, by changing the welding torch angle to a smaller angle and setting the welding torch angle to θ _{3 ', which is smaller than θ 3} , it is possible to weld even if the gap distance between members is large. Since the arc discharged from the torch reaches the inner side of the curved portion, it is easier to hit the upper and lower parts to be welded, and the parts to be welded can be joined together more reliably.

If the gap distance (n mm) between the parts is greater than the fifth threshold (e.g. 1 mm) and less than the seventh threshold (e.g. 3 mm), the welding position by the welding torch is the upper side. A position shifted by the predetermined distance + α (for example, 1 millimeter) in the negative X-axis direction (that is, the direction toward the back of the curvature) from the intersection of the extension line of the side surface of the welding target member 201 and the lower welding target member 202. is the welding position. In other words, the welding position is a position shifted by α in the direction toward the back of the curvature from the welding position shown in FIG. In this way, the welding torch is shifted by the predetermined distance +α from the intersection of the extension line of the side surface of the upper welding target member 201 and the lower welding target member 202 in the negative direction of the X axis (that is, the direction toward the back of the curved part). By doing so, even if the gap distance between the parts is large, the arc discharged from the welding torch will reach the back of the curved part, making it easier to hit the upper and lower parts to be welded, making it more reliable. The members to be welded can be joined together.

<Function of work distribution unit 34>
FIG. 19 is a block diagram illustrating functions implemented in the work distribution 34. In this embodiment, the work distribution section 34 includes a processing section 3410 and a storage section 3420. The processing section 3410 includes a welding order determining section 3411, a welding work assignment determining section 3412, and a welding execution instruction section 3413. Further, the storage section 3420 of the work distribution section 34 includes a welding order storage section 3421, a distribution condition storage section 3422, a robot characteristic storage section 3423, and a work history storage section 3424.

The welding order determining unit 3411 divides the work route into three types of areas described below based on the gap information received from the measurement control unit 24 and the information regarding the welding priority recorded in the welding priority storage unit 3421. The welding order is determined by dividing it. FIG. 20 is a diagram showing an example of information recorded in the welding priority storage section 3421. Three area classifications are defined in the welding priority storage unit 3421 according to the size of the gap distance (G) at each position of the work route 200.

If the gap distance G is smaller than the first threshold (Th1), the area is classified into area A. In area A, automatic welding by the welding robot is determined to be OK, and the priority of automatic welding work is set to "high." On the other hand, if the gap distance is larger than the first threshold (Th1) and smaller than the second threshold (Th2), it is classified into area B. In area B, automatic welding by the welding robot is determined to be OK, and the priority of automatic welding work is set to "low." If the gap distance is larger than the second threshold (Th2), it is classified into area C. In area C, automatic welding by the welding robot is determined to be NG, automatic welding by the welding robot is stopped, and the user is notified of this via the controller 3 or the input/output unit 1.

The welding order determining unit 3411 classifies the work route into areas A, B, or C based on the gap information received from the measurement control unit 24, welds area A preferentially, and performs welding in area A. The welding order is determined so that the welding work in area B is performed after the work is completed. Generally, in order to weld a position with a large gap distance with the same strength as a position with a small gap distance, it is necessary to relatively increase the output of the welding torch compared to a position with a small gap distance. At this position, a relatively large amount of heat is applied to the workpiece 2 to be welded. Therefore, the amount of deformation of the welding object 2 due to heat increases, and welding operations tend to cause problems such as distortion and increased gap distance in other areas of the work path. On the other hand, since the gap distance in area A is sufficiently small, welding work can be performed without generating large amounts of heat during welding. Therefore, by determining the welding order so that area A, which has a smaller gap distance, is welded before area B, welding quality is less likely to deteriorate due to thermal deformation of the welding object during welding. I can do it.

Further, the area classified as area C is not automatically welded by the welding robot, but areas A and B other than area C are automatically welded by the welding robot. In this way, for area C where the gap distance is large and it is difficult to weld with a welding robot, automatic welding can be prohibited and the welding work can be performed manually, which improves the overall quality of welding on the welding target. Easier to maintain.

The welding work allocation determining unit 3412 determines the allocation (distribution) of welding work to be performed by a plurality of welding robots. The allocation conditions can be set and changed by the user via the input/output unit 1 or the controller 3 from a plurality of distribution conditions recorded in the distribution condition storage unit 3422. FIG. 21 is a diagram showing an example of a plurality of distribution conditions recorded in the distribution condition storage section 3422. For example, the following three distribution conditions are set in the distribution condition storage unit 3422.

(1) "Work quality priority" Work is distributed to a plurality of welding robots based on the priority (high/low) determined by the welding order determining unit 3411 for each area classified according to the size of the gap distance. A specific example of performing distribution under this distribution condition will be described later.

(2) "Priority for shortening work time" Work is distributed so that the working distance (or working time) of each welding robot is approximately uniform when the work paths are distributed. Here, the tip angle (welding torch angle) of an articulated robot generally used in automatic welding and the like is determined by driving not only the movable part near the tip but also other movable parts in a complex manner. Therefore, in actual automatic welding operations using articulated robots, etc., the robot drive time required to change the angle of the welding torch cannot be ignored, so in order to reduce work time, the robot drive time must be taken into account. It is desirable to distribute work on a work path to multiple welding robots. The robot characteristic storage unit 3423 stores the drive time of each welding robot, which is necessary when moving the movement route and angle of the welding torch of the robot according to the work path, or the information necessary to calculate the drive time, as well as information necessary for calculating the drive time of each welding robot. The spatial range reached by the tip position of the welding robot is recorded. By selecting this distribution condition of "prioritize work time reduction", the actual robot driving time and each By considering the range that can be welded by a welding robot, it is possible to perform work distribution that reduces the change in posture of each welding robot and shortens the welding work performed by a plurality of welding robots.

(3) "Maintenance equal priority" Based on the history information of each welding robot's operating distance (or operating time) stored in the work history storage unit, the difference in cumulative distance or cumulative time between welding robots is reduced. Determine the work assignment for each welding robot so that

The welding execution instruction unit 3413 issues a welding execution command to the plurality of welding robot control units 33 corresponding to each welding robot according to the welding work allocation to each welding robot determined by the welding work allocation determining unit 3412. send and have the welding work performed. The work history storage unit 3424 records performance information of welding work actually performed by the welding robots from each welding robot control unit 33 in the work history storage unit 3424. Here, the welding robot control section 33 does not necessarily need to be provided for each welding robot, and if the computing performance of the hardware is sufficiently high, one welding robot control section 33 can control multiple welding robots. It may be configured to control a welding robot.

FIG. 22 is a diagram showing an example of a control flowchart of the work sharing section 34. First, the work route and gap information are acquired from the measurement control unit 24 (step 201). Next, the welding order determining section 3411 determines the welding order based on the information acquired from the measurement control section 24 and the information recorded in the welding priority storage section 3421 (step 202). Next, the welding work allocation determining unit 3412 determines the welding work allocation (step 203). Next, the welding execution instruction section 3413 transmits a welding command to each welding robot control section 33 (step 204).

FIGS. 23 to 25 are diagrams showing examples in which the welding work allocation determining unit 3412 allocates work to two welding robots 30a and 30b when "work quality priority" is set as the distribution condition. Welding work allocation determining unit 3412 selects points where welding execution times are expected to overlap (welding start point, welding intermediate point, welding end point) in order to avoid contact between two welding robots that distribute welding work. etc.), it is necessary to set the work route so that the work routes are not closer than a predetermined distance, and furthermore, based on the distribution condition of "work quality priority", it is necessary to set the work route so that the It is necessary to distribute work to welding robots. In other words, the work route in area A where the gap distance is relatively short (less than a predetermined value, e.g. Th1) is longer than the work route in area B where the gap distance is relatively long (greater than a predetermined value, e.g. Th1). A post-distribution work path to be distributed to each welding robot is generated so that the work is executed first.

In the example shown in FIG. 23, a welding robot 30a is installed on the upper side of the drawing, and a welding robot 30b is installed on the lower side. Also, based on the results of measuring the members 201 and 202 to be welded, the welding order determining unit 3411 selects two areas A with high priority (inside the dotted line frame) and two areas B with low priority (inside the solid line frame). An example of determining (within) is shown. The welding work allocation determining unit 3412 sets the lower ends of the two areas A as the welding start points of the work routes 200a and 200b of each welding robot 30a and 30b, and sets the upper end of the area B adjacent to the upper side of each area A as the welding start point of each work route 200a. , 200b is the welding end point. In this way, if there are multiple areas A and B, welding can be done by distributing the work route connecting one set of Areas A and B to one welding robot. Since there is no action to move the position of the welding torch other than the action, the working time can also be shortened.

In the example shown in FIG. 24, a welding robot 30a is installed on the upper side of the drawing, and a welding robot 30b is installed on the lower side. In addition, based on the results of measuring the members 201 and 202 to be welded, the welding order determining unit 3411 determines that area A with high priority is placed in one place in the center (within the dotted line frame), and areas with low priority are located above and below area A. B shows an example in which two locations (within the solid line frame) are determined. Welding in area A can be assigned to either the welding robots 30a or 30b, but since area B on the welding robot 30a side is narrower than area B on the welding robot 30b side, welding work The allocation determining unit 3412 allocates area A and upper area B to welding robot 30a, and allocates lower area B to welding robot 30b. In addition, a work path 200a in which the lower end of area A is the welding start point and the upper end of upper area B is the welding end point is assigned to the welding robot 30a, and the lower end of lower area B is the welding start point and the upper end of lower area B is the welding point. A work path 200b having a welding end is assigned as a work for the welding robot 30b. In this way, if there is one area A, by distributing the work so that the work path for welding area A is assigned to one welding robot, the position of the welding torch can be moved other than during welding operations. Since no movement occurs, the working time can also be shortened.

In the example shown in FIG. 25, a welding robot 30a is installed on the upper side of the drawing, and a welding robot 30b is installed on the lower side. Furthermore, based on the results of measuring the members 201 and 202 to be welded, the welding order determining unit 3411 determines that area C, which is determined to be an area in which automatic welding is not performed (NG area), is located at one location in the center (within the dotted line frame); An example is shown in which two low-priority areas B (within the solid line frame) are determined on both sides of the top and bottom of C. Since area C is an area where automatic welding is not possible, no work route is set in area C, and the work route 20a set in upper area B is assigned to the welding robot 30a and set in lower area B. Work path 20b is assigned to welding robot 30b. In this way, if there is a mixture of area C where automatic welding is not performed and area A or B where automatic welding is performed, the work route set for areas other than area C is allocated to each welding robot. Therefore, even if the area C includes a large gap distance where automatic welding cannot be performed, automatic welding can be performed only in areas where the gap distance is small.

Setting work assignments to multiple welding robots in advance based on three-dimensional CAD data is disclosed in Patent Document 1, etc., but in reality, the shape and position of the welding target member are determined based on the three-dimensional CAD data. As there were deviations from the ideal shape and position, the work allocation was not necessarily optimal, but as explained in the above embodiment, the actual shape of the part to be welded was measured by the measuring robot. However, since work is allocated to multiple welding robots taking into consideration the position of the planned welding location and gap distance, it is possible to allocate welding work that is appropriate for the actual condition of the parts to be welded. .

In the embodiment described above, as shown in FIG. 1, the measurement control unit 24 does not directly communicate with the measurement robot 20, but exchanges measurement command signals and measurement data with the measurement robot via the measurement robot control unit. Furthermore, an example has been shown in which the work distribution section 34 does not directly communicate with the welding robot 30, but exchanges welding command signals and welding performance data with the welding robot via the welding robot control section 33. With this configuration, the welding system can be improved by incorporating external equipment such as the measurement control section 24 and the work distribution section 34 without changing the hardware or software of each existing robot and the control section of the robot. It becomes possible to construct.

Although the present embodiment has been described above, the above embodiment is for facilitating understanding of the present invention, and is not for construing the present invention in a limited manner. The present invention may be modified and improved without departing from the spirit thereof, and the present invention also includes equivalents thereof.

In the embodiment described above, an example in which the present invention is applied to a welding system that performs welding using a robot arm has been described, but the present invention is not limited to welding applications, but can also be applied to sealing work, bonding work, etc. It is also possible to apply the present invention to a work system that includes other work such as gluing on the boundary part, and in that case, the welding torch may be replaced with a discharge part that discharges sealant or adhesive. is possible, and the working nozzle section in this specification shall be interpreted to include a welding torch and a discharge section. Furthermore, when work other than welding is included, "welding path" in this specification can be interpreted as being replaced with "work route".

1: Input/output section, 2: Welding object, 3: Controller, 10: Processor,
11: Memory, 12: Storage, 13: Transmission/reception unit, 15: Bus,
20: Measuring robot, 21, 31: Arm, 22: Sensor,
23: Measurement robot control unit, 24: Measurement control unit, 30: Welding robot,
32: Welding torch, 33: Welding robot control section, 34: Work distribution section,
200: Working path, 201, 202: Welding target member, 220: Arc,
100: Welding system, 2410, 3410: Welding condition setting section,
2420, 3420: Storage unit, 2411: Measurement condition determination unit,
2412: Point cloud data acquisition unit, 2413: Gap measurement unit,
2414: Welding torch position/angle determining unit, 2415: Working route generating unit,
2421: Measurement condition storage unit, 2422: Three-dimensional CAD data storage unit,
2423: Measurement point group data storage unit, 2424: Torch position/angle condition storage unit,
2425: Gap storage unit, 2426: Work route storage unit,
3411: Welding order determining unit, 3412: Welding work allocation determining unit,
3413: Welding execution instruction section, 3421: Welding priority storage section,
3422: Distribution condition storage unit, 3423: Robot characteristics storage unit,
3424: Work history storage unit

Claims (8)

A work system that performs work to weld or join target members,
a measuring robot that measures the shape of the target member;
a plurality of work robots that perform the work on the target member;
a work route generation unit that generates a work route including work position information based on measurement data measured by the measurement robot;
A work system comprising: a work distribution unit that divides the work route into a plurality of parts and distributes the divided work route to the plurality of work robots. The working system according to claim 1,
The measurement data measured by the measurement robot includes a gap distance between the target members, and the work system The working system according to claim 2,
The work route that the work distribution unit distributes to the plurality of work robots includes the work route where the gap distance is shorter than the predetermined value, and the work route where the gap distance is longer than the predetermined value. A work system, which is a work route. The work system according to claim 1 or 2,
comprising a robot characteristic storage unit that stores characteristics of the plurality of work robots,
The work distribution unit distributes the work path to the work robots so that the operating distance or operation time of each work robot, which is estimated based on the characteristics, is approximately uniform among the plurality of work robots. Distribute, work system. The work system according to claim 1 or 2,
comprising a work history storage unit that stores history information of the working distance or working time of each of the plurality of working robots,
The work distribution unit is configured to distribute the work route to the work robots based on the history information so that a difference in cumulative values of the movement distance or the movement time is reduced. The work system according to claim 1 or 2,
A work system in which a coordinate system of the measurement robot and a coordinate system of the work robot are the same coordinate system. The work system according to claim 1 or 2,
The work system wherein the measurement data measured by the measurement robot is three-dimensional point group data of the target member. A work method using a system for performing work of welding or joining target members, the method comprising:
Measuring the shape of the target member using one or more measuring robots,
Generating a work route including information on work positions based on measurement data measured by the measurement robot,
A working method, wherein the working route is divided into a plurality of parts, and the divided working route is distributed to the plurality of working robots.

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