WO2016139766A1

WO2016139766A1 - Assembly motion-teaching device

Info

Publication number: WO2016139766A1
Application number: PCT/JP2015/056279
Authority: WO
Inventors: 博文田口; 中須　信昭
Original assignee: 株式会社日立製作所
Priority date: 2015-03-04
Filing date: 2015-03-04
Publication date: 2016-09-09

Abstract

The purpose of the present invention is to implement an assembly motion-teaching technology capable of creating teaching data in a short time. An assembly motion-teaching device for a multi-arm robot is characterized: in being provided with a storage unit in which part information, robot information and hand/tool-part category information are stored; and in performing a process for extracting, from the part information, part assembly order and part category and on the basis thereof, assigning a tool or hand and an arm for handling a part to be assembled, and a process for extracting, from the robot information, possible part supply/placement positions that can be handled by said robot, establishing a coordinate system having the center position of the robot as the starting point, calculating the angle from a direction orthogonal to the front surface of the robot, and generating an arm movement path with respect to the part on the basis of said angle.

Description

Assembly operation teaching device

The present invention relates to a technique for teaching an assembling operation to an assembling robot.

When using robots in assembly automation to generate assembly operation data, direct teaching is usually performed while operating the robot directly. In this direct teaching, it is necessary to teach all of a series of operations that should be desired by the robot. In addition, complicated teaching work or long-time teaching work has been a heavy burden on the teaching worker.

In recent years, the diversification of customer needs has shifted the product production form from low-mix, high-volume production to multi-variable, variable-volume production, and assembly using a robot is also forced to support a wide variety of products. The burden is to be increased at an accelerated rate.

Therefore, for example, Japanese Patent Laid-Open No. 63-295192 (Patent Document 1) is an invention relating to an automation technique for reducing the work burden of teaching. Patent Document 1 describes an exhaustive search method using “optical search” as an example for obtaining an optimal solution for an operation procedure, or a method using “graph expression” as an example for obtaining a suboptimal solution.

JP-A-63-295192

The exhaustive search method by “optical search” in Patent Document 1 has a heavy calculation load and takes time to calculate. In addition, the method of obtaining a sub-optimal solution based on “graph expression” in Patent Document 1 requires time to create a graph expression. That is, the technique of Patent Document 1 requires a long time to generate teaching data.

Also, with the teaching data of Patent Document 1, the operation time of the robot could not be shortened sufficiently.

An object of the present invention is to realize an assembly operation teaching technique capable of creating teaching data in a short time.

In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-mentioned problems, and an example is given below.
An assembly operation teaching device for a multi-arm robot,
A database and a control unit,
The database stores part information and robot information,
The part information includes an assembly order, and the robot information includes a main body position, an arm ID, and candidate positions that can be handled by the arm.
The control unit extracts the assembly order from the parts information, extracts the arm information from the robot information, assigns the parts to the robot arm in the assembly order, and arm candidate positions from the robot information. And a process for assigning each part to one of the candidate positions, a coordinate system with the center position of the robot as the origin is set for the set part position, and is orthogonal to the robot front axis An assembly operation teaching apparatus, comprising: processing for calculating an angle from a direction; and processing for generating an operation path of an arm with respect to the component based on the angle.

According to the present invention, teaching data can be generated in a short time.

It is a figure which shows the system configuration | structure of an assembly operation | movement teaching system. It is a figure which shows an example of the data table of the components information. It is a figure which shows an example of the data table of the robot information. 6 is a diagram illustrating an example of hand / tool-part type information 113. FIG. It is a figure which shows the operation | movement flow which concerns on the assembly operation | movement teaching apparatus of Example 1. FIG. FIG. 4 is a detailed flowchart of step 130. It is an example of matching of a robot arm and a part. It is an example of matching of a robot arm and a part. It is a figure which shows the operation pattern of the left and right arms of a double-arm robot. It is a figure which shows the operation pattern of the left and right arms of a double-arm robot. It is a figure which shows the operation pattern of the left and right arms of a double-arm robot. It is a figure which shows the operation pattern of the left and right arms of a double-arm robot. It is a figure which shows the operation pattern of the left and right arms of a double-arm robot. It is operation | movement explanatory drawing of the left-right arm of a double-arm robot. It is operation | movement explanatory drawing of the left-right arm of a double-arm robot. It is a figure which shows the response | flow flow when interference generate | occur | produces. It is a figure which shows the operation | movement flow of the assembly operation | movement teaching apparatus in Example 2. FIG. It is operation | movement explanatory drawing of the left-right arm of a double-arm robot. It is a figure which shows the operation | movement flow of the assembly operation | movement teaching apparatus in Example 2. FIG. It is a component re-layout flowchart. It is a component re-layout flowchart. It is a figure which shows an example of an input screen.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[System Overview]
FIG. 1 is a diagram showing a system configuration of an assembly operation teaching system. The assembly operation teaching system includes an assembly operation teaching device 100, an input device 101 for inputting data to the assembly operation teaching device 100, a display device 102 for displaying a teaching state or input value in the assembly operation teaching device 100, and model data. A 3D-CAD device 104 that generates component information is provided with a vision system 105 that supplements data not created by the 3D-CAD device 104 with a camera or a scanner. The input device 101, the display device 102, the 3D-CAD device 104, and the vision system 105 of this embodiment are connected to the assembly operation teaching device 100 via a network, but may be part of the assembly operation teaching device 100. In this embodiment, an assembly motion teaching system applied to motion teaching of a multi-arm robot, particularly a double-arm robot will be described, but the present invention is not limited to a double-arm.

[Assembly operation teaching device]
The assembly operation teaching device 100 includes a DB 110 and a control unit 200. The DB 110 is a database configured by a storage device in the assembly operation teaching apparatus 100, and stores part information 111, robot information 112, and hand / tool-part type information 113. The control unit 200 includes an allocation unit 201, an operation path generation unit 202, an interference determination unit 203, and an assembly time calculation unit 204. Each part will be described in detail below.

[DB110]
First, each information of DB110 is explained in full detail.

<Part information 111>
An example of the data table of the component information 111 is shown in FIG. The component information 111 of the present embodiment includes, for example, component ID, component type, assembly order, and information (for example, effective length, mass, and installation surface friction coefficient) specifying torque that can be handled without holding other arms. ing.

<Robot information 112>
An example of the data table of the robot information 112 is shown in FIG. The robot information of this embodiment includes, for example, the robot ID, the position of the robot body, the arm ID of the robot, the arm position, the candidate positions registered for parts supply and part assembly, the hand and tools that can be handled, and the time of work Includes torque generated by the tool.

<Hand / Tool-Part Type Information 113>
The hand / tool-part type information 113 is information for specifying a hand or tool that can be handled for each part type. An example of the data table of the hand / tool-part type information 113 is shown in FIG. The hand is for gripping parts, claw type (eg, 2 claw type, 3 claw type), gripping type (eg, gripping the part with inner closing, type gripping the part with outside opening), suction type There are types such as finger type. The tool is a tool such as a screwdriver or a spanner necessary for assembling the parts.

[Overview of Control Unit 200]
The assignment unit 201 assigns to each part an arm, a hand, and a tool that handle the part.

The operation path generation unit 202 reads the supply position and the assembly position of each component, and generates an operation path of an arm that performs conveyance between them.

The interference determination unit 203 determines whether interference occurs in the operation path generated by the operation path generation unit 202.

The assembly time calculation unit 204 calculates the time required for assembling the parts based on the operation path generated by the operation path generation unit 202.

Hereinafter, the function of each part of the assembly operation teaching device will be described in more detail along with the operation flow.

[Operation flow of assembly operation teaching device]
FIG. 5 is an operation flowchart of the assembly operation teaching apparatus of the present embodiment.

When the start of the assembly operation teaching device 100 is started (START step 120), the assignment unit 201 first acquires the part information 111 from the DB 110. If there is insufficient information, the allocating unit 201 acquires the information from the 3D-CAD device 104 or the vision system 105 and stores it as the component information 111 in the DB 110 (step 121).

Next, the allocation unit 201 acquires the robot information 112 from the DB 110 (step 122).

Next, the allocating unit 201 acquires the assembly order of components from the component information 111 (step 123).

Next, the assignment unit 201 extracts the robot body position from the robot information 112, and sets a coordinate space with the robot body position as the origin on the robot installation surface. In the case of a dual-arm robot, this coordinate space has the front central axis as the Y axis and the orthogonal direction as the X axis (step 124). When the front central axis is not specified, the arm position of the robot information 112 is extracted and specified from the arrangement. Instead of the XY coordinate system, a polar coordinate system using an angle θ and a distance r with the origin at the apex from the plus side of the X axis may be used.

Next, the assignment unit 201 extracts the supply assembly candidate positions from the robot information 112 and sets each position on the coordinate space set in step 124. Further, the component of the component information 111 is arranged at the candidate position. Then, an angle θ formed by each component position with the origin at the apex is calculated from the plus side of the X axis (step 125).

Next, the allocating unit 201 acquires information for specifying the number of robot arms N _a from the robot information 112. If the robot information 112 does not include information specifying the number of arms N _a , the display device 102 prompts the user to input the number of arms N _{a of the} robot via the input device 101. The allocating unit 201 acquires the number of robot arms N _a through input by the user and stores it in the robot information 112 (step 126).

Subsequently, the allocating unit 201 refers to the hand / tool-part type information 113 in FIG. 4 by using the part type in the part information 111 in FIG. 2 as a reference key, so that a tool (for example, A screwdriver or a wrench necessary as a tool corresponding to the screw is assigned to the assembly of the part (step 127).

Subsequently, the allocating unit 201 similarly refers to the hand / tool-part type information 113 using the part type of the part information 111 as a reference key, so that the hand used for assembling the part can be used as the part operation. Assign (step 128). In addition, by providing a function for automatically determining an appropriate hand or tool, or by providing a function for allowing the user to input an appropriate hand or tool through the input device 101, it is possible to deal with a case where there is no corresponding data in the table. It is good also as a possible structure.

The part-tool association (step 127) and the part-hand association (step 128) are collectively referred to as step 138. After this step 138 is completed, the arm according to the present embodiment is associated with each component (step 130). Details of step 130 will be described later with reference to FIG.

After step 130, the motion path generation unit 202 generates an arm motion path (step 131).

Next, the interference determination unit 203 performs, for example, an interference check in the arm, hand, or arm operation path (step 132).

The assembly time calculation unit 204 calculates the movement time by dividing the operation path by the unit movement speed. Next, the assembling time calculation unit 204 counts the number of times of hand switching by checking whether or not there has been a change from the previous hand, and multiplies the number of times of hand switching by a preset time for one hand switching. Thus, the hand switching time is calculated. Further, the assembly time calculation unit 204 calculates the time required for assembling the parts of the robot by adding the movement time, the hand switching time, and the actual work time. This calculation calculates not only the individual parts but also the integrated value of the working time up to that point. (Step 133).

The assembly time calculation unit 204 further determines the work time calculated in step 133 (step 134). The determination condition is determined to be YES if it is shorter than a preset threshold value. It is possible to repeat a plurality of times and use the shortest time as a condition of YES. However, in order to generate teaching data in a shorter time, in this embodiment, a threshold value is used as a criterion. Further, this determination is made by both the assembling time of the individual parts and the integrated value of the assembling time of the parts so far.

If the determination of the assembly time (step 134) is Yes, the motion path generation unit 202 generates robot motion data (step 135).

If the determination of the assembly time (step 134) is No, the process returns to step 129.
<Step 130>
Next, the association between the robot arm and the part in step 130 will be described with reference to FIGS. FIG. 6 shows a detailed flowchart of step 130, and FIGS. 7 and 8 show examples of correspondence.

First, in accordance with the assembly order of parts, parts are selected by the number of robot arms (in this embodiment, the number of arms is 2 because a dual-arm robot is used) (step 156). The rule with which the arm located on the negative side of the X axis takes charge is applied to a component having a larger absolute value with respect to the positive side (step 157). This rule is applied to all the parts (step 158), and when the condition is satisfied, the process proceeds to arm operation path generation (step 131). Although it is assumed that all parts, tools, and hands can be used for each arm, the arm may not be handled depending on the tool or hand. In that case, the robot component information 111 is acquired. Next, by using the component type included in the component information 111, a hand and a tool that can handle the component type are acquired from the hand / tool-component type information 113. Next, an arm number that can handle the acquired hand and tool is extracted from the robot information 112. As a result, the arm that can be assigned to the work of each part is specified, and it can be determined which arm should be assigned to the part, tool, and hand.

FIG. 7 is a view of the robot and the parts layout state as seen from above the robot. Here, reference numeral 300 denotes a robot main body, which shows a robot (two-arm robot) provided with two arms. 310l is the left arm of the

robot

300, and 320r is the right arm of the robot 300. 420y is an axis passing through the approximate center O of the robot main body 300 and passing toward the front side of the robot, and is set as the Y axis (second axis). An orthogonal axis is set as an X axis (first axis) 410x. In the figure,

reference numerals

501a, 502b, 503c, 504d, 505e, 506f, and 507g denote the parts supply positions to be assembled, and the assembly is performed in alphabetical order of the subscripts. Reference numeral 510 denotes an assembly area where parts are assembled. Also, in this figure, the angle formed by the X axis, which is the first axis, and the part takes the part 504d as an example, and a line segment passing through the center of the part 504d and passing through the origin O is drawn as 430. The angle formed by the minute 430 and the X axis can be expressed as θn.

FIG. 8 illustrates an example in which parts are associated with robot arms according to this embodiment. Since the reference numerals in FIG. 8 are the same as those in FIG. 7, the reference numerals already described are omitted. First, the

parts

501a and 502b which are No. 1 and No. 2 in the assembly order will be described. Similar to the description so far, the angles formed by the X axis of the

parts

501a and 502b can be expressed as θA and θB, respectively, by drawing

line segments

450 and 440, respectively. Here, in the rule of step 157 in FIG. 6, in the selected part, the part with the larger absolute value of the angle formed with the first axis is in charge of the arm located on the negative side of the first axis. And attach the arm. In other words, since the larger angle of θA and θB is handled by the arm located on the negative side of the X-axis, that is, the left arm, θA> θB in the example of this figure, so the component 501a is moved by the left arm. The component 502b is handled by the right arm. Here, the left arm 310l moves in the direction of the arrow 311 and holds the part 501a (pick operation), then moves in the direction of the dashed arrow 312 and moves to the assembly area 510 (place operation). It moves in the direction of the arrow 321 and holds the part 502b (same pick operation), then moves in the direction of the broken arrow 322 and moves to the assembly area 510 (same place operation). Here, for the sake of simplicity, FIGS. 7 and 8 do not show a hand for gripping a part on the arm.

Subsequently, the movement patterns of the left and right arms of the dual-arm robot will be described with reference to FIGS. FIG. 9 is a diagram summarizing the operation patterns of the left and right arms and the operation rules at that time. This operation rule is assumed to be applied in the processing in the assignment unit 201, arm-part association (step 130), arm operation path generation (step 131), and operation path generation (steps 132 to 135). (1) When the left and right arms can move independently, (2) When the left and right arms are in order, (3) When the left and right arms cooperate, (4) The left and right arms cooperate, and carry-over operation FIGS. 10 to 13 show patterns to be performed arranged in time series.

FIG. 10 shows a pattern in which (1) the left and right arms can move independently, and the left arm is in charge of parts A and C, and the right arm is in charge of parts B and D at the same time. Yes.

FIG. 11 shows the case where the left and right arms are in the same order in the assembly work. For example, after A is picked and placed with the left arm, the part B must be picked and placed with the right arm. An example that should not be shown. At this time, the right arm cannot perform the pick operation or the place operation at the timing of STEP2 in FIG. 7, and the place operation on the right arm is not performed until the left arm places the part A at the timing of STEP2. It shows that it becomes possible.

FIG. 12 shows (3) the case where the left and right arms cooperate. In the first STEP1 and STEP2, the left arm and the right arm perform the picking and placing operation for the parts A and B, respectively, and then STEP3. , STEP 4 shows a pattern in which the left arm and the right arm cooperate to pick and place the same part.

FIG. 13 shows (4) a pattern in which the left and right arms cooperate and perform a change-over operation. In this example, in the first STEP1 and STEP2, the left arm and the right arm are picked for the parts A and B, respectively. After the operation & place operation is performed, an example is shown in which the left arm and the right arm cooperatively change parts or deliver parts in STEP3, STEP4, and STEP5. In STEP3, the part C is first picked by the left arm, and then the place operation is started. The place destination at this time is the right arm, and the left arm place = the right arm pick operation (STEP 4). Thereafter, the right arm performs the place operation of the part C in STEP5, and the left arm starts the picking operation of the part E at the same timing, and reduces the time during which the left and right arms are not moving as much as possible, thereby improving workability. It has become.

These operation patterns (1) to (4) are obtained from the processes in the allocation unit 201 and the operation path generation unit 202, the arm-part association (step 129), the arm operation path generation (step 130), and the operation path. This is executed by generation (steps 131 to 135).

Here, the operation of the left and right arms of the double-arm robot will be described again with reference to FIGS. FIG. 14 is an operation explanatory view showing an example in which the parts in the state where the assembly is advanced and the left and right arms of the double-arm robot in FIG. 13 are associated with each other. Since the reference numerals in FIG. 14 are the same as those in FIGS. 7 to 8, the reference numerals already described are omitted.

Referring to FIG. 14, the

parts

503c and 504d that are the third and fourth in the assembly order will be described. As described above, the angles formed by the X axis of the

parts

503c and 504d are determined by plotting

line segments

470 and 460 connecting the origin O and the approximate center of the part 503c and the origin O and the approximate center of the part 504d. These can be expressed as θC and θD, respectively. Here, considering the same rule as explained in step 157 of FIG. 6, since θC> θD in the example of FIG. 14, pick operation with the left arm and component 504d with the right arm, Responsible for operations such as place operations. Here, the left arm 310l moves in the direction of the arrow 313 and holds the part 503c (pick operation), then moves in the direction of the broken arrow 314 and moves to the assembly area 510 (place operation), and the right arm 320r moves to the arrow at the same timing. It moves in the direction 323, holds the part 504d (same pick operation), then moves in the direction of the broken arrow 324 and moves to the assembly area 510 (same place operation).

Next, the case where interference occurs during the robot arm operation will be described with reference to FIG. Since the reference numerals used in FIG. 15 are the same as those used in FIGS. 7 to 8, the details are omitted here, but a hand that grips a part at the tip of a robot arm as a new form close to an actual robot. FIG. In FIG. 15, the hand attached to the tip of the left arm 310l is 311l, and the hand attached to the tip of the right arm is 321r. Here, consider the case where, for example, the

components

503c and 504d are close to each other in FIG. 14 described above. The angle formed by the component 503c is θC as described above, and the angle formed by the component 504d is θD. Therefore, as in FIG. 14, the left and right arms 310 l and 320 r try to pick up the

parts

503 c and 504 d allocated to them (pick operation). Here, when the distance between the parts is small, the hands 311l and 321r at the tip of the arm may interfere with each other.

Fig. 16 shows the response flow when interference occurs. FIG. 16 is a diagram showing in detail the interference check (step 132) in FIG. 5 and is a process performed by the interference determination unit 203. In FIG. 16, when the interference check function is started (step 132a), the presence / absence of interference is confirmed (step 132b). When there is no interference, the next step, assembly time calculation (step 133), is executed. . On the other hand, when there is interference, only one of the arms is operated by a predetermined amount (step 132d), the other arm is retracted by a predetermined amount (step 132e), and the presence / absence of interference is confirmed again (step 132f and step 132). 132b) This process is repeated until there is no interference. By this processing, it is possible to generate a route in which the hands do not interfere with each other in time.

So far, examples of various arm operations in a dual-arm robot have been described. Here, as an example in which the left and right arms perform coordinated operations, a case of performing a work of fastening screws to parts will be described. In fact, when tightening screws, if the mass of the component is small relative to the torque of the robot's screw tightening, or if the friction coefficient of the component installation surface is small, the component will be tightened if the component is not held. It may rotate.

Therefore, in the present embodiment, when the mass of the component information 111, the effective length of the component (effective friction) and the installation surface friction coefficient, and the generated torque of the robot information 112 satisfy the following conditional expression 1, The other arm is responsible for holding the parts.

Screw tightening torque T> Part mass × Weight acceleration g × Friction effective part length × Installation surface friction coefficient… Condition 1
Thereby, it is possible to prevent unnecessary rotation of components during screw tightening.

On the other hand, if this conditional expression 1 is not satisfied, the vacant arm (the arm that is not in charge of screw tightening) will be used to grip the next component to be assembled.

FIG. 17 shows an operation flow of the assembly operation teaching apparatus according to the second embodiment. FIG. 17 is a partial improvement in FIG. 5 in that the part is held by one arm so that the part does not rotate with the screw tightening torque when the part is the target of screw tightening. The determination is based on the operation flow of the assembly teaching apparatus shown in FIG. 5 as to whether or not the part to be handled is accompanied by screw fastening (step 130a), and in the case of Yes, the condition shown in FIG. It is determined whether or not the component to be screwed is rotated (step 130b), and in the case of Yes, the component is continuously held by the arm and the hand holding the component during the screw tightening operation. According to the aspect of the present embodiment, it is possible to eliminate the problem that the component rotates during the screw tightening operation.

In the first embodiment, the case where each component is only one (use one) has been described. However, in the case of actual part assembly, the same part may be used in plural. First, the case where the left arm and the right arm are each equipped with a hand (not shown) capable of handling the same parts will be described with reference to FIG. FIG. 18 is a diagram showing an operation pattern of the left and right arms of the double-arm robot. Since the reference numerals used in FIG. 18 are the same as those in FIGS. 7 to 8, the description thereof is omitted here. As an example of using the same part, a case where there are two parts 502b will be described. Here, it is assumed that the part assembling procedure is in the order of 501a → 502b → 502b → 503c. FIG. 19 shows an operation flow of the assembly operation teaching apparatus according to the third embodiment. FIG. 19 is a diagram in which the invention is expanded in step 130 for associating an arm with a part shown in FIG. Here, FIG. 18 and FIG. 19 are used for explanation.

As described above, in FIG. 18, the angle of the component 501a is θA, the angle of the component 502b is θB, and θA> θB according to the rule. First, the left arm is assigned to the component 501a and the right arm is assigned to the component 502b. (FIG. 19: When step 157 is executed). Next, if the correspondence between the parts and the arms is assigned according to the same rule, this time θB> θC, so it is possible to handle the part 502b with the left arm 310l and the part 503C with the right arm 320r (FIG. 19, when executing step 157) ).

Next, a case will be described in which the number of parts and the layout are the same, and a hand (not shown) that can handle the part 502b is attached to only one arm. Here, it is assumed that the hand handling the component 502b is attached only to the right arm (320r). As in the previous examples, since θA> θB, the part 501 a is first picked by the left arm and placed in the assembly area 510. At the same time, the right arm 320r picks the part 502b and places it in the assembly area 510 (when executing step 157 in FIG. 19). Next, since θB> θC, according to the rules so far (FIG. 19, step 157), the left arm 310l picks up the part 502b and the right arm picks up the part 503c and places it. However, since the arm 310l on the left side does not have a hand for handling the part 502b, it cannot actually handle the part. Therefore, a new rule was set. According to this rule, when a part to be handled (pick, place, etc.) cannot be handled due to hand incompatibility, etc., the hand corresponding to the part is given priority (step 157d in FIG. 19). ).

However, if it is faster to replace the hand attached to the right arm 310l and replace it with the left arm, work with the combination of the arm and parts with the shorter working time, including hand replacement. A rule is set (FIG. 19, step 157b and step 157c). In other words, the arm is associated with the component so that the difference in work time between the left and right arms is minimized.

What has been described so far is an invention in which an appropriate arm is associated with a part corresponding to the assembly order with respect to a predetermined part layout, but in this embodiment, the part layout is optimized. is there.

In the fourth embodiment, a layout in which components are brought close to the assembly area by a predetermined amount based on a predetermined component layout is generated, and between the arms (under the operating conditions of the arms in accordance with the assembly procedure) And part) are checked, and if there is no interference, the part is brought closer to the assembly area by a predetermined amount. As a result, the component layout can be made as close to the assembly area as possible without interference of the arms and components, so that the amount of movement of the arm can be reduced, and finally the assembly work time can be reduced.

Fig. 20 shows a part re-layout flow diagram where one part is used. First, the number N of parts is set (step 651). This step 651 can be performed in steps (step 180 or 181) before and after the robot motion data generation (step 135) in FIG.

Next, the counter n for counting the number of parts is reset (n = 0) (step 653), then the counter n is incremented by 1 (step 655), and the position of the part with the part number n is determined with respect to the initial part layout. Re-layout is performed by approaching the assembly area (510 in FIG. 10) by a fixed amount. This part re-layout is performed by updating the information of the part information 111 in FIG. 1 or the information in the 3D-CAD device 104 of FIG. Subsequently, the motion path generation unit 111 in FIG. 1 checks for interference when the arm is operated (step 657), and checks whether there is interference in consideration of the interference margin amount set in advance or input (step 657). 658). This process is performed for all parts and continues until interference occurs. As a result, the layout state at the step before the first round in which interference occurs is that each component is close to the assembly area, and the arm operation is minimized, so it is possible to determine a component layout that shortens the assembly work. It becomes.

FIG. 21 shows a flow when there are a plurality of parts used. First, the number of types N of parts and the total number NN of parts are extracted (step 601), and how many parts are used for assembling is confirmed (step 602). Subsequently, the parts are ranked in descending order of usage. (Step 603), the parts are re-laid out around the assembly area for each part with a high ranking (Step 604). Thereafter, the re-layout for each component described in FIG. 20 is performed (steps 651 to 660).

As described above, with the method described with reference to FIGS. 20 and 21, it is possible to generate a component layout that minimizes the operation of the robot arm.

FIG. 22 shows an example of the input screen of the assembly operation teaching apparatus according to the present invention. This screen is displayed on the display device 102 in FIG. 1, and an input operation is performed with the input device 101 including a keyboard and a mouse. In FIG. 22, an input unit 901 for inputting a product name (file name) of 3D-CAD data, a display unit 902a for displaying 3D-CAD information of product completion, and a part 902b displaying a part layout layout Show.

Also, an assembly operation simulation display screen 904 for displaying an assembly operation simulation is shown. An assembly order generation execution button 910 that executes generation of an assembly order, and an assembly teaching button 911 that executes generation of robot operation data shown in step 135 in FIG. 5 are shown. In addition, as the input screen for the optimal component layout described in the fourth embodiment, an input unit 909 for inputting a step value for each component for the optimal component layout, an input unit 912 for inputting an interference margin amount of components and hands, and a component layout An optimization execution start button 903 is arranged.

As described above, the present invention has been described by taking the assembling operation teaching device as an example, but the scope of the invention is not limited to this, and may be applied as an assembling teaching method.

According to the above embodiment, when using a dual-arm robot, it is easy to determine which part should be associated with which side of the left and right arms based on the initial position of each part and the position (angle) of the robot. Therefore, it is possible to reduce the calculation load and shorten the calculation time.

Further, not only the assembly work time of individual parts by the arm operation but also the integrated value is calculated and evaluated by the assembly time calculation unit 204, so that the assembly time can be shortened.

Furthermore, since it is possible to change the part layout so that the movement distance of the arm is minimized with respect to a predetermined part layout, it is possible to further reduce the assembly time.

The present invention is not limited to a double-arm robot having two arms, and it goes without saying that the present invention can also be applied to a multi-arm robot including three or more arms.

Also, layout rearrangement can be applied not only to multi-arm robots but also to single-arm robots.

100 ... Assembly operation teaching device,
101 ... Input device,
102... Display device,
104 ... 3D-CAD device,
105 ... Vision system,
110 ... DB,
111 ... Part information,
112 ... Robot information,
113... Hand / tool-part type DB,
201 ... allocation part,
202... Operation path generation unit,
203 ... Interference determination unit 204 ... Assembly time calculation unit 300 ... Dual-arm robot body,
310l ... The left arm of the double-arm robot,
320r ... Right arm 410x of the double-arm robot ... first coordinate axis 420y passing through the substantial body center of the double-arm robot ... second orthogonal to the first coordinate axis passing through the substantial body center of the double-arm robot Coordinate

axes

501a, 502b, 503c, 504d, 505e, 506f, 507g ... part 510 ... assembly area

Claims

An assembly operation teaching device for a multi-arm robot,
A database and a control unit,
The database stores part information and robot information,
The part information includes an assembly order,
The robot information includes a body position, an arm ID, and candidate positions that can be handled by the arm,
The controller is
A process of extracting an assembly order from the part information;
Extracting arm information from the robot information and assigning the parts to the robot arm in an assembly sequence;
Extracting a candidate position of the arm from the robot information and assigning each component to one of the candidate positions;
A process of setting a coordinate system with the center position of the robot as an origin for the set component position and calculating an angle from a direction orthogonal to the robot front axis;
An assembly operation teaching apparatus, which performs processing for generating an operation path of an arm with respect to the component based on the angle.
In claim 1,
When teaching the fastening operation to the robot,
The robot information in the database includes a tool that can be handled by each arm, and a torque T that is generated during a fastening operation.
The parts information in the database includes part type, part mass M, effective length L, friction coefficient μ,
The database includes tool information corresponding to each component type,
The controller is
Extracting the component type from the component information,
Identify the corresponding tool from the part type,
Extracting torque T generated during assembly work with the tool specified from the robot information,
Extracting the mass M, friction coefficient μ, and effective length L of the part from the part information,
An assembly operation teaching apparatus comprising: a process of assigning a component holding operation to one arm and assigning a fastening operation to another arm when the following (Equation 1) is satisfied.
Torque T> part mass M × gravity acceleration g × (friction effect) part length L × friction coefficient μ (Equation 1)
In claim 1,
Furthermore, the control unit
A process of calculating a movement time from the arm movement path and the movement speed;
When the tool assigned to the part needs to be replaced, a process for calculating the tool replacement work time;
An assembly operation teaching apparatus that performs a process of calculating an assembly operation time based on the movement time and the tool replacement operation time.
In claim 3,
An assembly operation teaching apparatus, wherein operation path generation is repeated until the assembly operation time is shorter than a threshold value.
In claim 4,
An assembly operation teaching apparatus, wherein operation path generation is repeated until the sum of the assembly operation time of each component and the assembly operation time of all components becomes shorter than a threshold value.
In claim 4 or 5,
An assembly operation teaching apparatus, wherein the candidate position to which a part is assigned is changed when the operation path generation is repeated.