WO2016151862A1 - Assembly teaching device and assembly teaching method - Google Patents

Abstract

An assembly teaching device for a robot that performs assembly work comprises: a data reading unit for acquiring assembly sequence information for a part to be assembled, dimensional information for the part to be assembled, information on a surface that contacts another part, information on placement on equipment, robot dimensional and placement information, and robot hand dimensional and placement information; an assembly point-generating unit for calculating the assembly point for the part to be assembled from placement information for said part on assembly equipment; an assembly direction-calculating unit for calculating an assembly direction from information on the surface of the part to be assembled that contacts another part; a retreat point-generating unit for performing a simulation to determine whether or not there is a neighboring part that will cause interference and when there is a neighboring part, calculating a retreat point (Ps) for avoiding the neighboring part, and calculating, regardless of the presence of a neighboring part, a retreat point (Pb) immediately prior to assembly and a retreat point (Pa) immediately after assembly; a program-generating unit for generating a robot movement program from the assembly sequence information and the calculated assembly point and retreat points; and an assembly teaching output unit for outputting the generated robot movement program to an external apparatus.

Description

Assembly teaching apparatus and assembly teaching method

The present invention relates to an assembly teaching apparatus for parts and an assembly teaching method.

When assembling parts using a robot, the robot operation program registers the coordinates and orientation by moving the robot to a point where the robot passes, such as the part pick-up position and assembly position, so-called operation points. In general, it is created by using a teaching playback method for programming connected actions. The operation points that need to be registered with the teaching playback method when assembling parts are not only the final target position such as the pickup position or assembly position of the part, but also the via position that passes until the final target position is reached, or just before the final target position. There are a plurality of retraction positions for one operation. Further, in the case of assembly work using a robot, since the combination is not a linear operation, the operation points are arranged in a complicated manner in a three-dimensional space.

When parts are assembled by an articulated robot, the trajectory for moving the parts to the final assembly position immediately before the final assembly position is a straight line in a state where the posture of the part is accurately maintained by linear interpolation control. It is necessary to make an action take place. However, if linear interpolation control is performed with coordinated movements of each joint, the speed will slow down, so the distance for linear interpolation control should be shortened as much as possible, and robot movement between other operating points will coordinate all joints. In order to increase productivity, it is generally performed to employ many PTP trajectory controls that are simultaneously controlled.

The teaching playback method includes a direct method in which a robot is directly operated by a controller to register an operating point, and a robot model similar to a real space is constructed on a computer space, and a simulator is virtually operated without operating the robot directly. There is an offline method for registering operating points. In either method, as the operating point of the retracted position that is taught and registered is farther from the final target position, the robot passes an unnecessarily long path through linear interpolation control, which takes extra time for assembly and reduces productivity. To do. Also, if other parts are arranged in the vicinity, depending on the registered operating point of the retraction position, there is a risk of collision with other parts and damage, so a skilled worker is required to teach the operating point. It was.

As a background art in this technical field, there is JP-A-2006-4262 (Patent Document 1). This publication provides "a method for creating robot teaching data that can create data for offline teaching in consideration of the relationship between the work scheduled to be executed at each work target point and the characteristics of the end effector. On the computer. In the off-line teaching method in which a virtual robot is operated to teach the robot, the work content that the robot is scheduled to perform and the tool characteristics of the tool used for the work match for each work target point on the work on which the robot works. "An off-line teaching method characterized by including a conformity determination step (step S3) for determining whether or not it has been performed" (see summary).

There is also JP-A-11-194812 (Patent Document 2). This publication provides "offline teaching method capable of obtaining a more appropriate motion trajectory so that data change after teaching is minimized in offline teaching of a robot. For each teaching target point, for each teaching target point, the step (S2) of extracting the approaching angle for the robot to work and the robot approaching angle at each extracted teaching target point are all compared, A step of grouping teaching target points whose angles fall within a predetermined allowable range and creating an operation trajectory for connecting the teaching target points in each group so that the robot continuously operates in each group ( Off-line teaching method characterized by having S3) ”(see summary).

JP 2006-4262 A Japanese Patent Laid-Open No. 11-194812

However, since the methods of Patent Documents 1 and 2 determine the feasibility and optimize the operating points registered in advance, the optimization of the operating points themselves depends on the skill level of the teacher. Also, it is necessary to register the operating point of the retracted position immediately before the final target position.

The present invention has been made in view of such circumstances, and using the data in which the positional relationship between parts, robots, and the like is three-dimensionally illustrated, the operation point (assembly) of the final target position in assembly work is provided. It is an object of the present invention to provide an assembly teaching device that calculates an operation point (retraction point) at a retracted position immediately before the final target position and teaches it to a robot.

In order to solve the above problems, in the present invention, an assembly teaching apparatus for a robot that performs an assembly operation includes an assembly order information of parts to be assembled, dimension information of parts to be assembled, contact surface information with other parts, equipment, and the like. The data reading unit that acquires the above placement information, robot dimensions, placement information, and robot hand dimensions, placement information, and the assembly points of the parts are calculated from the placement information of the assembly target parts on the assembly equipment. Cause the interference by simulating the assembly of the assembly target part by the robot hand and the assembly direction calculation part for calculating the assembly direction from the contact surface information of the assembly target part and other parts of the assembly target part The presence / absence of a peripheral part is determined, and if there is a peripheral part, a evacuation point Ps for avoiding the peripheral part, a evacuation point Pb immediately before assembly regardless of the presence / absence of the peripheral part, and a evacuation point Pa immediately after assembly. Calculate A evacuation point generation unit, an assembly sequence information, a program generation unit that generates a robot operation program from the calculated assembly point and evacuation point, and an assembly teaching output unit that outputs the generated robot operation program to an external device Configured.

In order to solve the above-described problem, in the present invention, in the assembly teaching device, the retreat point generation unit, according to a peripheral component determination distance E ′ designated and input by a user, The provisional value and the retraction point Pb immediately before assembly are calculated, the conveyance by the evaluation target robot from the retraction point Ps to the retraction point Pb is simulated, the peripheral component determination distance E for each assembly target component is calculated, According to the peripheral component determination distance E, the presence / absence of peripheral components that cause interference is determined again.

In order to solve the above-described problem, in the present invention, in the assembly teaching device, the retraction point generation unit determines whether or not the assembly target part is an insertion part. The length of the insertion part of the part is extracted from the dimension information, it is determined whether there is a peripheral part that interferes in the assembly operation of the insertion part, and if there is a peripheral part that interferes, The distance (peripheral component distance) between the assembly point and the interfering peripheral component farthest in the direction opposite to the assembly direction is extracted (peripheral component distance), and the peripheral component is avoided from the insertion part length of the component and the peripheral component distance. A retraction point Ps is calculated, a retraction point Pa immediately after assembly is calculated from the peripheral component distance, and a distance between the assembly point and the retraction point that avoids the peripheral component is calculated immediately after the assembly point and immediately after the assembly. Generate a evacuation point longer than the distance to the evacuation point It was configured to.

In order to solve the above-described problems, the present invention provides an assembly teaching method for a robot that performs an assembly operation, assembly order information of parts to be assembled, dimension information of parts to be assembled, and contact surface information with other parts. , Obtaining the placement information on the equipment, the dimensions of the robot, the placement information, the dimensions of the robot hand, and the placement information, and calculating the assembly points of the parts from the placement information of the parts to be assembled on the assembly equipment Simulating the assembly direction of the assembly target part by the robot hand and determining the presence or absence of peripheral parts that cause interference When there is a peripheral part, a retreat point Ps for avoiding the peripheral part, a retreat point Pb immediately before assembly regardless of the presence or absence of the peripheral part, and a retreat point Pa immediately after assembly are calculated. And step was to have the assembly order information, and generating a robot operation program from the calculated assembly point and save point, and outputting the generated robot operation program to an external device.

According to the present invention, when inserting and assembling parts, it is possible to automatically generate operating points in consideration of the length and insertion length of parts and the positional relationship with peripheral parts. In addition, since it is possible to register an operating point that does not depend on the skill level of the instructor and the operating distance of the robot can be minimized, an assembly teaching device that contributes to productivity improvement can be obtained.

It is a schematic block diagram of the assembly teaching apparatus concerning the Example of this invention. It is a figure explaining the element of the three-dimensional drawing information in connection with the Example of this invention. It is a flowchart of the assembly teaching process concerning the Example of this invention. It is the figure which showed the processing flow of the evacuation point calculation in the assembly teaching apparatus concerning the Example of this invention. It is the figure which showed the processing flow of the evacuation point calculation of the insertion component in the Example of this invention. It is a figure explaining the assembly operation | movement of the robot when other components exist around the assembly | attachment object component. It is a figure explaining the assembly operation of the robot when there are no other parts around the part to be assembled. It is a figure explaining the assembly operation | movement of the robot when an assembly | attachment object component is inserted in the positioning pin of an assembly | attachment object component. It is the figure which showed the processing flow of the evacuation point calculation of the non-insertion part in the Example of this invention. It is a figure explaining the assembly operation | movement of the robot when other components exist around the assembly | attachment object component. It is a figure explaining the assembly operation of the robot when there are no other parts around the part to be assembled. It is a figure explaining operation | movement of the robot in the assembly operation by a robot. FIG. 11 is a diagram showing a robot position Pt at an arbitrary time t when moving in a circular arc from a retreat point Ps that avoids peripheral parts to a retreat point Pb just before assembly in an assembly operation by the robot. It is a figure explaining the relationship of the distance E for determining the holding | grip state of the assembly object components by a robot hand, and the presence or absence of a peripheral component. It is a figure explaining the example of a display screen of the assembly teaching apparatus displayed on a display part. It is a figure explaining the example which displayed the assembly | attachment point and retraction | saving point output by the assembly teaching apparatus with the robot simulator.

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

1 to 16, a description will be given of a part assembly operation as an example of an assembly teaching apparatus according to the present invention.

<Configuration of assembly teaching device>
FIG. 1 shows an example of a schematic configuration diagram of an assembly teaching apparatus 100 of the present invention.
The assembly teaching apparatus 100 can be configured on a general-purpose computer, and the hardware configuration thereof includes an arithmetic unit 110 including a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only). Memory 120, HDD (Hard Disk Drive) storage unit 120, keyboard and mouse input device 130, LCD (Liquid Crystal Display) display device, various output devices, etc. A display unit 140, a communication unit 150 including a NIC (Network Interface Card), and the like.
The communication unit 150 is connected to an external CAD device 160, a robot controller 170, a robot simulator 180, and the like via a network 190.

The storage unit 120 has an area 121 for storing an assembly teaching process program for executing the assembly teaching process of the present invention, and a CAD created by the CAD device 160 and received via the network 190 or mounted on the same device 100. An area 122 for storing three-dimensional drawing information such as parts, equipment, and robot hands created by a system (not shown), and an assembly order that describes the assembly order of parts created by a CAM system (not shown) An information storage area 123 and an assembly teaching result storage area 124 for storing generated operation points, robot operation programs, and the like are provided.

The calculation unit 110 implements the following functional units by loading and executing the assembly teaching processing program 121 stored in the storage unit 120.
The calculation unit 110 includes a data reading unit 111 that reads the three-dimensional drawing information 122 and the assembly order information 123, and an assembly point generation unit that calculates an operating point of the assembly position that is the final target position from the three-dimensional drawing information 122. 112, an assembly direction calculation unit 113 that calculates the assembly direction of the part from the three-dimensional drawing information 122, and a retraction that calculates the operating point of the retraction position immediately before the final target position from the three-dimensional drawing information 122 and the assembly sequence information 123. The point generator 114, the program generator 115 in which the generated operation points are arranged in order and described as a robot operation program, the robot controller 170 that directly moves the output destination robot, or the robot simulator 180 that confirms the robot operation on the computer. Output the robot operation program generated in the file format and store the assembly teaching result And an assembly teaching output unit 116 which records to 124.

The assembly teaching apparatus 100 may be configured to include other teaching function programs, CAD systems, CAM systems, and the like in addition to the assembly teaching processing program 121. However, FIG. 1 shows only the functional units and storage areas related to the assembly teaching processing program 121 of the present invention.

<< 3D drawing information >>
The three-dimensional drawing information 122 read by the assembly teaching apparatus 100 does not necessarily have to be displayed as a three-dimensional image, and may be character information in which the dimensions of the parts and the coordinates at which the parts are arranged are stored.
For example, the three-dimensional drawing information 122 includes elements as shown in FIG. The elements are parts to be assembled, a robot hand, and a robot. When there are a plurality of each element, they are identified by ID. Eight types of items are stored in the parts. Information on the type of part, the length in the assembly direction, the length of the insertion part, the bounding box and the dimensions of the component surface, the contact surface number with other parts, on the equipment And information relating to the arrangement of the equipment (at the time of pickup) and the arrangement on the equipment (at the time of assembly) are stored. Three types of items are stored in the robot hand, and information regarding hand dimensions when gripping a part and dimensions of the gripping position of the part, and arrangement information on the robot are stored. Two types of items are stored in the robot, and dimension information between axes and arrangement information on equipment are stored. These pieces of information are input by a method of additionally writing as a property of the three-dimensional CAD model, a method of defining in a text format or an XML format, and the like.

<Operation of assembly teaching device>
FIG. 3 is a diagram illustrating a flowchart of the assembly teaching process according to the present invention. In the assembly teaching process, first, the data reading unit 111 reads the three-dimensional drawing information 122 and the parts assembly order information 123 (S801).
Secondly, the assembly point generation unit 112 extracts the arrangement of the assembly target parts stored in the three-dimensional drawing information 122 on the facility and calculates the assembly point Pm (S802). The assembly point Pm referred to here is position coordinate information and orientation information of the assembly target component when assembled to the assembly target component that is the final target position in the assembly operation. The assembly point Pm is defined as a point that coincides with the tip of the robot hand when the part to be assembled is gripped by the robot hand.

Third, the assembly direction calculation unit 113 extracts a contact surface with the other component to be assembled stored in the three-dimensional drawing information 122, and determines the assembly direction of the assembly target component from the positional relationship of the contact surface. Calculate (S803). For example, if the contact direction is one plane, the normal vector of the contact surface is the assembly direction, and if the contact surface is one cylindrical surface, the contact surface axis vector is calculated as the assembly direction. To do.
Fourth, the retraction point generation unit 114 calculates a retraction point (S804). The retraction point calculation will be described with reference to FIGS.

Fifth, using the assembly order information 123 and the assembly points and retraction points calculated in steps S802 and S804 in the program generation unit 115, a path connecting the assembly points and retraction points in order according to the assembly order is used as a robot operation path. Then, a program for robot operation is generated (S805).
Sixth, the assembly teaching output unit 116 outputs the generated robot operation program to the robot controller 170 or the robot simulator 180 and the assembly teaching result storage area 124 (S806).

<< Saving point calculation process in the saving point generation unit >>
FIG. 4 is a diagram illustrating a processing flow for calculating a retract point in the assembly teaching device according to the present invention. In the retraction point calculation, first, the insertion portion length information of the assembly target part stored in the three-dimensional drawing information 122 is acquired (S901).
Secondly, it is determined whether the assembly target part is an insertion part based on the acquired insertion part length information (S902). Judgment is made based on the presence or absence of insertion section length information. Parts such as screws and connectors in which insertion section length information is stored are determined to be insertion parts, and parts such as covers and boards that do not store insertion section length information are insertion parts. It is determined that it is not. However, there is a case in which a positioning hole is provided even if the part is determined not to be an insertion part because the insertion portion length information is not stored and is assembled by being inserted into a positioning pin. For this reason, in the case of a component type that is determined not to be an inserted component, the arrangement information on the equipment, the bounding box information, and the contact surface with other components when assembling the component stored in the three-dimensional drawing information 122 From the information, extract the positional relationship with other parts in contact with the part to be assembled, and if the part to be assembled at the time of assembly interferes with the bounding box of other parts in the vicinity, it is partially inserted inside the other part It is determined that the part is an inserted part. If it is an inserted part, a retraction point of the inserted part is calculated third (S910), and if it is not an inserted part, a retreat point of the non-inserted part is calculated third (S940).

《Evacuation point calculation process for inserted parts》
The retraction point calculation process (S910) of the inserted part will be described with reference to FIGS.
FIG. 5 is a diagram illustrating a processing flow in calculating a retract point for an inserted part. FIG. 6 is a diagram for explaining the assembly operation of the robot when other parts exist around the part to be assembled. FIG. 7 is a diagram for explaining the assembly operation of the robot when there are no other parts around the part to be assembled. FIG. 8 is a diagram illustrating the assembly operation of the robot when the assembly target component is inserted into the positioning pin of the assembly target component.

In the insertion part retraction point calculation process, the length M of the assembly target part and the length L of the insertion part shown in FIG. 6A or 7A are acquired from the three-dimensional drawing information 122 in step S911. Since the parts assembled by inserting into the positioning pins as described above are also inserted parts, as shown in FIG. 8 (A), the length of the positioning pins is as long as the parts are assembled by inserting into the positioning pins. Is obtained as the length L of the insertion part (data is stored in the insertion part length of the three-dimensional drawing information on the part to be assembled side).

In step S912, peripheral parts arranged within the periphery E ′ of the assembly target part are extracted. (When assembling a part to be assembled to a part to be assembled, check the possibility that the part to be assembled or the robot hand will interfere with existing peripheral parts in the process of assembling with the robot hand up to the final assembly position. As will be described later with reference to Fig. 13, the circular arc trajectory differs depending on the robot model, position, orientation, and trajectory interpolation method, so it is necessary to check for each assembly target part, but in this step, it was positioned at the final assembly position. (The distance E ′ for determining the periphery of the assembly target part is designated by the user and used as a temporary fixed value for determining the peripheral part.)
When extracting peripheral parts, the assembly order information 123 is used, and parts already assembled are determined as peripheral parts, and parts not yet assembled are not determined as peripheral parts. By increasing the peripheral parts according to the progress of the assembly work, the state of the assembly target in each scene can be reflected in the peripheral part determination.

In step S913, the presence / absence of peripheral parts is determined. Details of the determination of the peripheral parts will be described later. If there are peripheral parts, the process proceeds to step S921, and if not, the process proceeds to step S933. Since the subsequent processing differs depending on the presence or absence of the peripheral component, first, the case where the peripheral component exists will be described with reference to FIG.

When there are peripheral parts, in step S921, the assembly point Pm obtained by the assembly point generation unit 112, the assembly direction U of the assembly target part obtained by the assembly direction calculation unit 113, and the three-dimensional The distance H between the assembly point Pm shown in FIG. 6A and the front surface of the peripheral component is acquired from the configuration surface information of the peripheral component stored in the drawing information 122 and the arrangement information on the equipment. The surface farthest from the assembly point Pm in the direction opposite to the assembly direction U is extracted as the front surface in the component surface information of the peripheral parts and the arrangement information on the equipment, and the front surface and the assembly of the peripheral parts in the direction opposite to the assembly direction U The distance to the attached point Pm is calculated and set as the distance H.

In step S922, a retreat point Ps that avoids the peripheral components shown in FIG. 6A is calculated. At this time, when the coordinates of the assembly point Pm in the equipment are (Mx, My, Mz) and the coordinates of the retreat point Ps that avoids the peripheral parts are (Sx, Sy, Sz), the assembly point Pm and the surroundings The relationship with the retreat point Ps that avoids the part is expressed by the following equation using a unit vector u = (ux, ui, uz) in the assembling direction.
(Equation 1) (Sx, Sy, Sz) = (Mx, My, Mz) −s (ux, uy, uz)
(Expression 2) s = L + δ + H
Here, δ is a constant indicating a margin length of the retreat distance, and s is a distance between the retreat point Ps and the assembly point Pm.
The evacuation point Ps is arranged on the same axis in the assembling direction U with respect to the assembling point Pm. By calculating the evacuation point Ps that avoids the peripheral component defined by this calculation formula, the peripheral component is taken into consideration. It is possible to minimize the distance s from the assembly point to the retraction point and avoid interference with other parts.

In step S923, the retract point Pb immediately before assembly shown in FIG. 6B is calculated. At this time, when the coordinates of the retreat point Pb immediately before assembly in the equipment are (Bx, By, Bz), the relationship between the assembly point Pm and the retreat point Pb immediately before assembly is the unit vector u in the assembly direction. Is expressed by the following equation.
(Equation 3) (Bx, By, Bz) = (Mx, My, Mz) −b (ux, uy, uz)
(Expression 4) b = L + δ
Here, b is the distance between the retreat point Pb and the assembly point Pm.
The evacuation point Pb is arranged on the same axis as the assembling point Pm in the same way as the evacuation point Ps, and is calculated by calculating the evacuation point Pb immediately before the assembly defined by this calculation formula. It is possible to define a retract point closer to the point and minimize the distance b from the assembly point to the retract point.

In step S924, the retract point Pa immediately after the assembly shown in FIG. At this time, when the coordinates of the retreat point Pa immediately after assembly in the equipment are (Ax, Ay, Az), the relationship between the assembly point Pm and the retreat point Pa immediately after assembly is the unit vector u in the assembly direction. Is expressed by the following equation.
(Equation 5) (Ax, Ay, Az) = (Mx, My, Mz) −a (ux, uy, uz)
(Equation 6) a = δ + H
Here, a is the distance between the retreat point Pa and the assembly point Pm.

Since the parts are not gripped after the parts are assembled, it is not necessary to retreat to the retreat point Ps that avoids the peripheral parts before the assembly, and it is sufficient to retreat to a position considering only the peripheral parts. Similarly to the retraction points Ps and Pb, the retraction point Pa is arranged on the same axis in the assembly direction U with respect to the assembly point Pm, and by calculating the retraction point Pa immediately after the assembly defined by this calculation formula, It is possible to minimize the distance a from the assembly point to the retraction point when the component after assembly is not gripped. At this time, the distance s between the assembly point Pm and the retraction point Ps is longer than the distance a between the assembly point Pm and the retraction point Pa because of the gripping / non-holding relationship of the parts.

In step S925, the surrounding part determination distance E for each part to be assembled is determined by the evacuation point Ps calculated by the provisional value E ′ (if the evacuation point Ps is not calculated by the tentative value E ′ when there is no peripheral part. In this case, the retraction point Ps is provisionally set at a predetermined height above the retraction point Pb and used for the simulation of the robot.) The space between Pb is determined by the evaluation target robot and the trajectory interpolation control method used. A simulation of moving the assembly target part is performed, and calculation is performed according to (Equation 11) described later.

In step S926, peripheral components arranged within the periphery E of the assembly target component are extracted again using the calculated peripheral component determination distance E.
In step S927, if there is a peripheral part other than the peripheral part extracted in step S912 among the peripheral parts extracted in step S926, the process proceeds to step S921, and if there is no peripheral part, a retraction point calculation process for the inserted part is performed. finish.

Next, the case where there are no peripheral parts will be described with reference to FIGS. If there are no peripheral parts, a retraction point Pb immediately before assembly shown in FIG. 7A or FIG. 8A is calculated in step S933. At this time, the relationship between the assembly point Pm and the retraction point Pb immediately before the assembly is the same as in the case where there are peripheral parts (Equation 4).

In step S934, the retraction point Pa immediately after assembly shown in FIG. At this time, the relationship between the assembly point Pm and the retract point Pa immediately after the assembly is expressed by the following equation.
(Expression 7) a = ML−δ
Since the parts are not gripped after the parts are assembled, there is no need to retreat up to the retreat point Pb immediately before the assembling, but it is necessary to retreat in consideration of the length ML of the part where no parts are inserted. Don't be. By calculating the evacuation point Pa immediately after assembly defined by these formulas, the evacuation point is retracted from the assembly point when the part after assembly is not grasped in consideration of the part where no part is inserted. It becomes possible to minimize the distance a to the point. At this time, the distance b between the assembly point Pm and the retraction point Pb is longer than the distance a between the assembly point Pm and the retraction point Pa because of the gripping / non-holding relationship of the parts.

In the parts that are inserted and assembled into the positioning pins shown in FIG. 8C, the distance to be retracted after the assembly is different, and is expressed by the following formula.
(Equation 8) a = δ
This is because it is possible to retreat without considering the length of the portion not inserted after assembly. By calculating the evacuation point Pa immediately after assembly defined by these formulas, the evacuation point is retracted from the assembly point when the part after assembly is not grasped in consideration of the part where no part is inserted. It becomes possible to minimize the distance a to the point. At this time, the distance b between the assembly point Pm and the retraction point Pb is longer than the distance a between the assembly point Pm and the retraction point Pa because of the gripping / non-holding relationship of the parts.

The evacuation point Ps for avoiding the peripheral parts calculated by the evacuation point generation unit 114, the evacuation point Pb immediately before assembly, and the evacuation point Pa immediately after assembly are opposite to the assembly direction calculated by the assembly direction calculation unit 113. When the vector is set from the assembly point, all the retraction points are set on the vector in the same direction. << Retraction point calculation process for non-inserted parts >>
The non-inserted part retraction point calculation process S940 will be described with reference to FIGS. FIG. 9 is a diagram for explaining a flowchart in the non-inserted part retraction point calculation process. FIG. 10 is a diagram for explaining the assembly operation of the robot when there are other parts around the part to be assembled. FIG. 11 is a diagram for explaining the assembly operation of the robot when there are no other parts around the part to be assembled.

In the non-inserted part retraction point calculation process, in step S941, the length M of the assembly target part stored in the three-dimensional drawing information 122 shown in FIG. 10 (A) or 11 (A) is acquired.
In step S942, peripheral components arranged within the periphery E ′ of the assembly target component (using the peripheral component determination distance E ′ specified by the user as in the description in step S912) are extracted. At this time, as in the case where the assembly target part is an insertion part, the assembly order information 123 is used, and already assembled parts are determined as peripheral parts, and parts not yet assembled are determined as peripheral parts. By not using the target, the state of the assembly target in each scene can be reflected in the peripheral component determination.

In step S943, it is determined whether there is a peripheral part. Details of the determination of the peripheral parts will be described later. If there are peripheral parts, the process proceeds to step S951. If there are no peripheral parts, the process proceeds to step S963. Since the subsequent processing differs depending on the presence or absence of the peripheral component, first, the case where the peripheral component exists will be described with reference to FIG.

When there are peripheral parts, in step S951, the assembly point Pm obtained by the assembly point generation unit 112 and the assembly direction calculation unit 113 are obtained in the same manner as in step S921 of calculating the retraction point of the insertion part. From the assembly direction U of the assembly target part, the configuration surface information of the peripheral part stored in the three-dimensional drawing information 122, and the arrangement information on the facility, the assembly point Pm and the peripheral part shown in FIG. Get the distance H from the front of

In step S952, a retreat point Ps that avoids the peripheral parts shown in FIG. 10A is calculated. At this time, the relationship between the assembly point Pm and the retreat point Ps that avoids the peripheral parts is expressed by the following equation.
(Equation 9) s = M + δ + H
By calculating the evacuation point Ps that avoids the peripheral part defined by this calculation formula, the distance s from the assembly point to the evacuation point is minimized in consideration of the peripheral part, and interference with other parts is also avoided. It becomes possible to do.

In step S953, a retract point Pb immediately before assembly shown in FIG. 10B is calculated. At this time, the relationship between the assembly point Pm and the retract point Pb immediately before the assembly is expressed by the following equation.
(Equation 10) b = δ
Unlike the case where the target part is an insertion part, the retraction point Pb immediately before assembly is calculated without considering the length of the insertion part. By calculating the retract point Pb immediately before assembly defined by this calculation formula, it is possible to define the retract point closer to the assembly point and minimize the distance b from the assembly point to the retract point. It becomes.

In step S954, the evacuation point Pa immediately after assembly shown in FIG. At this time, the relationship between the assembly point Pm and the retraction point Pa immediately after the assembly is the same as in the case of the insertion part (Equation 6). This is because the same calculation can be performed regardless of the component type when the component is not gripped. By calculating the retract point Pa immediately after assembly defined by this calculation formula, it is possible to minimize the distance a from the assembly point to the retract point when the component after assembly is not gripped. Become. At this time, the distance s between the assembly point Pm and the retraction point Ps is longer than the distance a between the assembly point Pm and the retraction point Pa because of the gripping / non-holding relationship of the parts.

Next, the case where there are no peripheral parts will be described with reference to FIG. If there are no peripheral parts, a retraction point Pb immediately before assembly shown in FIG. 11A is calculated in step S963. At this time, the relationship between the assembly point Pm and the retract point Pb immediately before the assembly is the same as in the case where there are peripheral parts (Equation 10). This is because the retraction distance is determined regardless of the length of the component because no component is inserted.

In step S964, a retract point Pa immediately after the assembly shown in FIG. At this time, the relationship between the assembly point Pm and the retraction point Pa immediately after assembly is the same as in the case of a component that is inserted into the positioning pin and assembled (Equation 8). This is because the positions of the parts to be assembled after assembly are the same regardless of whether or not they are inserted into the positioning pins. By calculating the evacuation point Pb immediately before assembly and the evacuation point Pa immediately after assembly defined by these equations, the distances b and a from the assembly point before and after assembly to the retract point are minimized. Is possible.

<< Determination of peripheral parts >>
The determination of peripheral components shown in steps S912 and S926 in FIG. 5 and steps S942 and S956 in FIG. 9 will be described with reference to FIGS.

FIG. 12 is a diagram for explaining the operation of the robot in the assembly work by the robot, and shows a case where a 6-axis driven vertical articulated robot is used as an example. In the assembly by the robot, the assembly target part 222 is gripped by the robot hand 210, the robot 250 is moved from the retreat point Ps that avoids the peripheral parts to the retreat point Pb just before the assembly, and the assembly is performed from the retreat point Pb just before the assembly. It is moved to the point Pm and assembled to the part 240 to be assembled. When moving from the retraction point Ps that avoids the peripheral parts to the retraction point Pb immediately before assembly, the robot 250 rotates the six operation axes J1 to J6 while fixing the posture of the assembly target part 222, and moves each operation. An arc as shown in FIG. 12 (A) is moved to the target position by an operation that combines the rotational movements of the shaft. At this time, as shown in FIG. 12B, when there is a peripheral part 231 in the vicinity, there is a possibility that the part 222 or the peripheral part 231 may be damaged due to interference with the peripheral part 231 during the assembling operation. For this reason, when the peripheral component 231 exists within the operation range of the robot 250 that holds the assembly target component 222, the robot is linearly moved from the retreat point Ps that avoids the peripheral component to the retreat point Pb immediately before the assembly point. There is a need.

FIG. 13 is a diagram showing the position Pt of the robot at an arbitrary time t when moving in a circular arc from the retraction point Ps that avoids the peripheral parts to the retraction point Pb just before assembly in the assembly work by the robot. is there. In the example shown in FIG. 13, since the assembly target part 222 is assembled in the −Z direction on the XY plane, there is no peripheral part that interferes during the assembly in the + Z direction. Therefore, from the state in which the assembly target part 222 is assembled to the assembly target part 240, it is determined whether there is a peripheral part within a predetermined distance E from the assembly target part on the XY plane. In the example shown in FIG. 13, the peripheral component 231 is determined as a peripheral component, and the peripheral component 232 is not determined as a peripheral component. The distance E for determining the presence or absence of peripheral parts is a range in which the robot moves on the XY plane when the robot makes a circular motion. Here, when the linear distance between the robot position Pt at the arbitrary time t and the retraction point Pb immediately before assembly is Et, the maximum value of the value Eo obtained by projecting the linear distance Et onto the XY plane indicates the presence / absence of peripheral parts. It becomes the distance E for determination. When the coordinates of the retract point Pb immediately before assembly is (Bx, By, Bz) and the coordinates of the robot position Pt at any time t are (tx, ty, tz) The distance E is expressed by the following formula.
(Equation 11) E = Eo + β
= Max _{0 ≦ t ≦ T} (√ {(tx−Bx) ² + (ty−By) ² }) + β
Here, T is the time from the retreat point Ps that avoids the peripheral parts to the retreat point Pb immediately before assembly, and β is the assembly time of the robot hand on the XY plane when the robot hand grips the assembly target part. This is the distance jumped out from the outermost periphery of the target part.

FIG. 14 is a diagram for explaining the relationship between the gripping state of the assembly target component by the robot hand and the distance E for determining the presence or absence of the peripheral component. As shown in FIG. 14A, when the assembly target part 222 protrudes from the robot hand 210 on the XY plane, the assembly target part 222 first interferes with the peripheral part during movement. Therefore, since it is necessary to determine the presence / absence of the peripheral component within the range of the distance E for determining the presence / absence of the peripheral component from the outermost periphery of the assembly target component 222, the distance for determining the presence / absence of the peripheral component with β being 0. E is calculated.
On the other hand, as shown in FIG. 14B, when the robot hand 210 partially protrudes from the assembly target part 223 on the XY plane, the robot hand 210 first interferes with the peripheral parts during the movement. . Therefore, the side on which the robot hand 210 is protruding determines the presence or absence of the peripheral component within the range of the distance E for determining the presence or absence of the peripheral component from the outermost periphery of the robot hand 210 instead of from the outermost periphery of the assembly target component 223. On the side where the robot hand 210 does not protrude, it is necessary to determine the presence or absence of the peripheral component within the range of the distance E for determining the presence or absence of the peripheral component from the outermost periphery of the assembly target component 223 as in FIG. Since the distance β that the robot hand jumps out of the outermost periphery of the assembly target part on the XY plane can be calculated from the bounding box of the part stored in the three-dimensional drawing information 122 and the hand dimension information at the time of gripping the part of the robot hand. Depending on the situation, the distance E for calculating the presence / absence of the peripheral part is calculated by adding the distance β that the robot hand has jumped from the outermost periphery of the part to be assembled on the XY plane.

The peripheral part determination distance E for each part to be assembled is the retraction point Ps calculated by the provisional value E ′ (if the retraction point Ps is not calculated by the provisional value E ′ determined that there is no peripheral part, retraction is performed. A evacuation point Ps is provisionally set at a predetermined height above the point Pb and used for the simulation of the robot.) Between the Pb, the robot to be evaluated uses the trajectory interpolation control method to be used, and the assembly target part is selected. A moving simulation is performed, the distance that the robot hand to be used has jumped out from the outermost periphery of the assembly target part is calculated, and the peripheral part determination distance E is obtained by (Equation 11).

13 and 14 show examples of assembling the parts on the XY plane, the distance E for determining the presence or absence of the peripheral parts and the distance β projected from the robot hand are calculated on the XY plane. The value is calculated according to the contact surface between the assembly target component and the assembly target component obtained from the contact surface information with other components stored in the three-dimensional drawing information 122. By determining the presence / absence of the peripheral component at the distance E defined by (Equation 11), it is possible to select the peripheral component to be subject to interference avoidance. This makes it possible to minimize the distance from the assembly point before and after assembly to the retraction point without setting the unnecessary retraction point Ps of peripheral parts.

<< Program generation procedure >>
A procedure for generating a program for robot operation including the generation of the saving points described above will be described with reference to FIGS. FIG. 15 is a diagram for explaining an example of a display screen of the assembly teaching apparatus 100 displayed on the display unit 140. The display screen 301 includes an input information setting field 302, an output destination setting field 303, an output result log display field 305, and an output button 304. In the input information setting field 302, a file storing the three-dimensional drawing information 122, which is input information of the assembly teaching apparatus 100, and a file storing the assembly order information 123 are designated, and an allowance length δ of the evacuation distance is input. To do. In the output destination setting field 303, the robot controller 170 or the robot simulator 180 is selected as the output destination, and the robot controller model and the robot simulator software are selected. When the output button 304 is pressed when the setting of the input information and the output destination is completed, a program for robot operation including generation of a save point is generated. The progress of the program generation output is displayed in the log display field 305.

In the log display field 305, the number of parts to be assembled is first extracted after the output is started, and the completion of assembly point generation is displayed. Next, it is displayed that the generation of the save point is completed for each extracted part. At that time, if it is a part determined to be an insertion part in the determination of whether or not it is an insertion part shown in step S901 in FIG. 4, the insertion length L is set to the peripheral part shown in step S913 in FIG. 5 and step S943 in FIG. If it is determined that there is a peripheral component in the presence / absence determination, the distance H between the assembly point in the assembly direction of the assembly target component and the front surface of the peripheral component is displayed. In FIG. 15, with respect to the four parts to be assembled, the result is that the ID1 and ID2 parts are non-inserted parts, the ID3 and ID4 parts are inserted parts, and the ID2 and ID4 parts are determined to be peripheral parts. is doing. After the generation of the saving points for the number of parts is completed, it is displayed that the generation of the robot operation program generated from the information of the assembly points and the saving points is completed. Finally, it displays that the generated robot operation program has been output in a file format that matches the output destination.

FIG. 16 is a diagram for explaining an example in which assembly points and retraction points output by the assembly teaching device are displayed on a robot simulator. 15 shows the generation result of the assembly point and the evacuation point in the four parts to be assembled shown in FIG. 15, the part ID1 in FIG. 15 is the part to be assembled 261 in FIG. 16, and the part ID2 in FIG. 15 is the part to be assembled in FIG. The component 262, the component ID 3 in FIG. 15 corresponds to the assembly target component 263 in FIG. 16, and the component ID 4 in FIG. 15 corresponds to the assembly target component 264 in FIG.

First, when the assembly target part 262 that is a non-insertion part is assembled to the assembly target part 261 in the U direction, the retraction point is determined to be the peripheral part, and there is a peripheral part in the flow shown in FIG. Is calculated by At this time, the distance s between the assembly point Pm and the retraction point Ps is longer than the distance a between the assembly point Pm and the retraction point Pa because of the gripping / non-holding relationship of the parts.

Next, after the assembly target part 262 is assembled to the assembly target part 261, it is determined that there is no peripheral part when the assembly target part 263 that is an insertion part is assembled in the U direction, and in the flow shown in FIG. Calculated when there are no peripheral parts. At this time, the distance b between the assembly point Pm and the retraction point Pb is longer than the distance a between the assembly point Pm and the retraction point Pa because of the gripping / non-holding relationship of the parts.

Finally, the retraction point when assembling the assembly target part 264 as the insertion part in the U direction after the assembly target part 262 is assembled to the assembly target part 261 is determined as the peripheral part, and FIG. Calculated when there are peripheral parts in the flow shown. At this time, the distance s between the assembly point Pm and the retraction point Ps is longer than the distance a between the assembly point Pm and the retraction point Pa because of the gripping / non-holding relationship of the parts.

According to the embodiment described above, the retracted position closest to the final target position is automatically set as the operating points Ps, Pb, and Pa in consideration of the component length M, the insertion length L, and the positional relationship H with the peripheral components. Since the operation point can be registered without depending on the skill level of the teacher and the operation distance of the robot can be minimized, it is possible to obtain an assembly teaching device that contributes to productivity improvement.

As described above, the present invention has been specifically described on the basis of the embodiment with the component assembly as an example, but the present invention is not limited to the embodiment of the present invention, and the pickup position at the time of picking up the component is defined as the final target position. Since the robot operation described above can be explained in the same manner, it is needless to say that the assembly teaching device with teaching of the operating point can be changed without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 100 ... Assembly teaching apparatus 110 ... Operation part 111 ... Data reading part 112 ... Assembly point generation part 113 ... Assembly direction calculation part 114 ... Retraction point generation part 115 ... Program generation unit 116 ... assembly teaching output unit 120 ... storage unit 121 ... assembly teaching processing program (storage area)
122 ... 3D drawing information (storage area)
123 ... Assembly order information (storage area)
124 ... Assembly teaching result 130 ... Input unit 140 ... Display unit 150 ... Communication unit 160 ... CAD device 170 ... Robot controller 180 ... Robot simulator 190 ... Network 210, 221 ... Robot hand 220 ... Parts to be assembled (inserted parts)
221 ... Parts to be assembled (inserted parts using positioning pins)
222 ... Parts to be assembled (non-insertable parts)
223 ... Parts to be assembled (non-insertable parts)
230 ... Peripheral parts 231 ... Peripheral parts 232 ... Peripheral parts 240 ... Parts to be assembled (no positioning pins)
241 ... Parts to be assembled (with positioning pins)
250 ... Robot 261 ... Assembly target part 262 ... Assembly target part (non-insertion part)
263 ... Parts to be assembled (inserted parts)
264 ... Parts to be assembled (inserted parts)
301 ... Assembly teaching device display screen 302 ... Input information setting field 303 ... Output destination setting field 304 ... Output button 305 ... Output result log display field Pm ... Assembly point Ps ... Retraction point Pb to avoid surrounding parts ... Retraction point Pa just before assembly ... Retraction point Pt just after assembly ... Point M in the middle of assembly ... Parts to be assembled Length L in the assembly direction of the insertion part H of the assembly target part H distance between the assembly point and the front surface of the peripheral part in the assembly direction of the part to be assembled δ E: Distance Et for determining presence / absence of peripheral parts Et ... Linear distance Eo ... Et projected on XY plane from point during assembly to retraction point just before assembly β・ Distance that the robot hand pops out from the outermost periphery of the part when gripping the part U ・ ・ ・ Assembly direction u ・ ・ ・ Single direction of assembly Position vector s: Distance between retraction point to avoid peripheral parts and assembly point b ... Distance between retraction point just before assembly and assembly point a ... Retraction point and assembly just after assembly Distance to point

Claims (10)

In an assembly teaching device for a robot that performs assembly work,
Assembling order information of parts to be assembled, dimension information of parts to be assembled, contact surface information with other parts, placement information on equipment, dimensions of robot, placement information, dimensions of robot hand, and placement information are acquired. A data reading section;
An assembly point generator for calculating assembly points of the parts from the arrangement information of the parts to be assembled on the assembly facility;
An assembly direction calculation unit for calculating an assembly direction from contact surface information with other parts to be assembled; and
By simulating the assembly of the parts to be assembled by the robot hand, the presence / absence of peripheral parts causing interference is determined, and if there are peripheral parts, the retreat point Ps for avoiding the peripheral parts and the presence / absence of the peripheral parts A retract point generation unit for calculating a retract point Pb immediately before assembly and a retract point Pa immediately after assembly;
A program generation unit that generates a robot operation program from the assembly order information, the calculated assembly point, and the retraction point;
An assembly teaching apparatus, comprising: an assembly teaching output unit that outputs the generated robot operation program to an external device. The assembly teaching device according to claim 1,
The retraction point generation unit
According to the peripheral component determination distance E ′ designated and input by the user, a retreat point Ps that avoids the peripheral component, or a provisional value thereof, and a retreat point Pb immediately before assembly are calculated.
Simulating the conveyance by the evaluation target robot from the retraction point Ps to the retraction point Pb, and calculating the peripheral component determination distance E for each assembly target component,
An assembly teaching apparatus, wherein the presence / absence of a peripheral component causing interference is determined again according to the peripheral component determination distance E. The evacuation point Ps for avoiding the peripheral parts calculated by the evacuation point generation unit, the evacuation point Pb immediately before assembly, and the evacuation point Pa immediately after assembly are the reverse directions of the assembly direction calculated by the assembly direction calculation unit. The assembly teaching apparatus according to claim 1, wherein when a vector is set from the assembly point, all the retraction points are set on a vector in the same direction. The assembly teaching device according to claim 1,
The retraction point generation unit
Determine whether the assembly target part is an inserted part or not,
In the case of an insertion part, extract the length of the part and the length of the insertion part in the assembly direction from the dimension information of the part to be assembled,
Calculate the retraction point Pb immediately before assembly from the length of the insertion part of the part,
Calculate the retract point Pa immediately after assembly from the difference between the length of the part and the length of the insertion part,
An assembly teaching apparatus characterized in that a retraction point is generated such that a distance between the assembly point and the retraction point immediately before the assembly is longer than a distance between the assembly point and the retraction point immediately after the assembly. The assembly teaching device according to claim 1,
The retraction point generation unit
Determine whether the assembly target part is an inserted part or not,
In the case of an insertion part, the part insertion length is extracted from the dimension information of the part to be assembled,
Determine whether there are any peripheral parts that interfere with the assembly operation of the insertion part,
When there is an interfering peripheral part, the distance (peripheral part distance) between the assembly point of the insertion part and the surface farthest in the direction opposite to the assembly direction of the interfering peripheral part is extracted. And
A retraction point Ps that avoids the peripheral part is calculated from the length of the insertion part of the part and the peripheral part distance,
Calculate the retraction point Pa immediately after assembly from the peripheral component distance,
An assembly teaching apparatus characterized in that a retraction point is generated such that a distance between the assembly point and a retreat point that avoids the peripheral part is longer than a distance between the assembly point and the retraction point immediately after the assembly. The assembly teaching device according to claim 1,
The retraction point generation unit
Determine whether the assembly target part is a part that is inserted into the protruding part of the assembly target part and assembled,
In the case of a part that is inserted and assembled into the protruding part of the assembly target part, the length of the protruding part of the assembly target part is extracted as the insertion part length of the assembly target part,
Calculate the retraction point Pb immediately before assembly from the length of the insertion part of the part,
An assembly teaching apparatus, wherein a retraction point is generated such that a distance between the assembly point and the retraction point immediately before the assembly is longer than a distance between the assembly point and the retraction point immediately after the assembly. The assembly teaching device according to claim 1,
The retraction point generation unit
Determine whether the assembly target part is an inserted part or not,
When the assembly target part is not an insertion part and there is no interfering peripheral part, the distance between the assembly point and the retract point immediately before assembly and the distance between the assembly point and the retract point immediately after assembly Generating an evacuation point that is equal to each other. The assembly teaching device according to claim 1,
The retraction point generation unit
Determine whether the assembly target part is an inserted part or not,
When the assembly target part is not an insertion part, the length of the part in the assembly direction is extracted from the dimension information of the assembly target part,
Determine whether there are any peripheral parts that interfere with the assembly operation of the non-insertion parts,
When there is an interfering peripheral part, the distance (peripheral part distance) between the assembly point and the surface farthest in the direction opposite to the assembling direction of the interfering peripheral part in the assembly direction of the non-insertion part. Extract and
A retraction point Ps that avoids a peripheral component is calculated from the length of the component in the assembly direction and the peripheral component distance,
Calculate the retraction point Pa immediately after assembly from the peripheral component distance,
An assembly teaching apparatus characterized in that a retraction point is generated such that a distance between the assembly point and a retreat point that avoids the peripheral part is longer than a distance between the assembly point and the retraction point immediately after the assembly. In an assembly teaching method for a robot that performs assembly work,
Assembling order information of parts to be assembled, dimension information of parts to be assembled, contact surface information with other parts, placement information on equipment, dimensions of robot, placement information, dimensions of robot hand, and placement information are acquired. Steps,
Calculating an assembly point of the part from the arrangement information of the part to be assembled on the assembly facility;
Calculating an assembly direction from contact surface information with other parts to be assembled; and
By simulating the assembly of the parts to be assembled by the robot hand, the presence / absence of peripheral parts causing interference is determined, and if there are peripheral parts, the retreat point Ps for avoiding the peripheral parts and the presence / absence of the peripheral parts A step of calculating a retract point Pb immediately before assembly and a retract point Pa immediately after assembly;
Generating a robot operation program from the assembly sequence information and the calculated assembly points and retraction points;
And a step of outputting the generated robot operation program to an external device. The assembly teaching method according to claim 9,
By simulating the assembly of the parts to be assembled by the robot hand, the presence / absence of peripheral parts causing interference is determined, and if there are peripheral parts, the retreat point Ps for avoiding the peripheral parts and the presence / absence of the peripheral parts The step of calculating the evacuation point Pb immediately before assembly and the evacuation point Pa immediately after assembly,
According to the peripheral component determination distance E ′ designated and input by the user, a retreat point Ps that avoids the peripheral component, or a provisional value thereof, and a retreat point Pb immediately before assembly are calculated.
Simulating the conveyance by the evaluation target robot from the retraction point Ps to the retraction point Pb, and calculating the peripheral component determination distance E for each assembly target component,
According to the peripheral component determination distance E, the presence / absence of the peripheral component causing the interference is determined again, and when there is a peripheral component, the retreat point Ps for avoiding the peripheral component and the immediately before assembly regardless of the presence or absence of the peripheral component An assembly teaching method, comprising a step of calculating a retract point Pb and a retract point Pa immediately after assembly.

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