Work support device and work support method

Abstract

Provided are a work assistance device and a work assistance method that automatically create a projected drawing suitable for designating a work region on a subject, regardless of the skill level of a worker or the like. This work assistance device has: a projected drawing creation function for projecting a work subject, which has a work subject surface that includes a work subject region on which work is performed by a robot, in a direction perpendicular to the work subject surface, thereby creating in a virtual space a projected drawing parallel to the work subject surface; a work region designation function for designating a work subject region in the projected drawing; and a work region conversion function for converting the location of the work subject region designated in the projected drawing to a location in the virtual space.

Description

Technical Field

[0001] The present invention relates to an apparatus and method for assisting work to be performed by a robot.

Background Art

[0002] Techniques are known for simulating various operations using a robot in advance using a simulation device. For example, in a bending process in which a robot grips a workpiece and supplies it to a bending machine, a simulation technique is well-known in which a development drawing of the workpiece is displayed so that an operator can determine the bending order of the workpiece (see, for example, Patent Document 1).

[0003] Also, a technique is well-known in which two-dimensional projection data is acquired using three-dimensional CAD data of an object so that only the necessary NC data can be selectively created (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] When an operator designates a part of an object to be worked on by a robot, such as a bending line of a workpiece, using a terminal or the like, the difficulty of the work varies greatly depending on how the object is displayed. For example, a workpiece that is a three-dimensional object is easier to specify its position and the like when represented by a two-dimensional image projected in a certain direction, but it is difficult to determine the optimal projection direction regardless of the operator's skill level.

Means for Solving the Problems

[0006] One aspect of the present disclosure is that a robot Bending process performs Bending line a projection function that projects an object having a work target surface including Bending line in a direction perpendicular to the work target surface to create a projection view parallel to the work target surface in a virtual space, a work part designation function that designates Bending line on the projection view, and a work part conversion function that converts the position of and the bending line is the intersection line of the object and a virtual plane in the virtual space, and the normal direction of the virtual plane does not coincide with any of the axial directions of the robot coordinate system in the virtual space designated on the projection view into a position in the virtual space.

[0007] Another aspect of the present disclosure is that a robot Bending process performs Bending line projecting an object having a work target surface including Bending line in a direction perpendicular to the work target surface to create a projection view parallel to the work target surface in a virtual space, designating Bending line on the projection view, and converting the position of it can be seen that the bending line is the intersection line of the object and a virtual plane in the virtual space, and the normal direction of the virtual plane does not coincide with any of the axial directions of the robot coordinate system in the virtual space designated on the projection view into a position in the virtual space.

Advantages of the Invention

[0008] According to the present disclosure, a projection view suitable for designating a work part on a workpiece can be automatically created regardless of the skill level of the operator or the like, so that the burden on the operator and the work time can be significantly reduced.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0010] FIG. 1 is a schematic block diagram of a system including a work support device and a robot according to a preferred embodiment. The system 10 includes at least one robot 12, a robot control device 14 that controls the robot 12, a work support device 16 that supports the work to be performed by the robot 12 by the processing described later, and a shape data storage device 18 that stores data (for example, CAD data) of the three-dimensional (3D) shape of the work object (work) of the robot 12. These devices are connected to each other so as to be communicable by wire or wirelessly.

[0011] The robot 12 is, for example, an industrial articulated robot, and is configured to be able to execute various operations such as bending processing and taking-out operations described later based on commands transmitted from the robot control device 14. The robot control device 14 includes a processor, a memory, etc., and is configured to control the robot 12 based on a prepared robot program, a simulation result of the work support device 16, etc.

[0012] The work support device 16 is, for example, a computer such as a personal computer (PC) that is independent of the robot control device 14, and includes a processor 20, a memory 22, an input unit 24 such as a keyboard or a touch panel, and a display 26 for executing the processes described later. However, the control device 14 and the work support device 16 can also be substantially integrated devices. The shape data storage device 18 is, for example, a CAD device and can store data such as 3D shape data of a workpiece. Also, the work support device 16 and the shape data storage device 18 can be substantially integrated devices.

[0013] The work support device 16 has a projected view creation function of creating, in a virtual space, a projected view obtained by projecting a work target surface, which is a part where the robot 12 performs work on the workpiece, in a direction perpendicular to the work target surface, using the three-dimensional data of the workpiece stored in the CAD device 18 or the like, and a work part setting function of setting, on the created projected view, a part where the robot 12 performs work. In the present embodiment, it is assumed that the processor of the work support device 16 is responsible for the projected view creation function and the work part conversion function, and the processor and the input unit are responsible for the work part designation function. Hereinafter, a specific example of the process in the work support device 16 will be described.

[0014] (Example 1) In this example, as an example of processing an object using a robot, an apparatus and method for performing a simulation of bending processing will be described. FIGS. 2 and 3 show a virtual space displayed on the display 26 or the like of the work support device 16. Here, it is assumed that a workpiece 30, which is a flat sheet metal, is gripped by the robot 12, and a simulation of processing (here, bending processing) the workpiece 30 is performed along a processing line (for example, a bending line) 34 specified on the work target surface 32 of the workpiece.

[0015] As one method of specifying the bending line 34, there is a method of setting a virtual plane 36 as shown in FIG. 3 in the virtual space and setting the intersection line of the workpiece 30 and the plane 36 as the bending line 34. Usually, since the bending of sheet metal is performed in the direction of the thinnest part of the sheet metal, it is preferable to specify the normal direction 38 of the plane 36 in a direction perpendicular to the thinnest direction of the sheet metal.

[0016] Here, as shown in FIGS. 2 and 3, if the directions of the respective axes of the robot coordinate system 40 in the virtual three-dimensional space are parallel to the respective sides of the workpiece 30, the operator can relatively easily specify the bending line 34 via the input unit 24 of the work support device 16 or the like by making a specification such that the normal direction 38 of the plane 36 coincides with one of the axis directions (here, the x direction) of the coordinate system 40.

[0017] However, as shown in FIG. 4, when the directions of the respective axes of the coordinate system 40 are not parallel to the respective sides of the workpiece 30, the normal direction 38 of the plane 36 does not coincide with any of the axis directions of the coordinate system 40. Therefore, before specifying the bending line 34, the operator must make an appropriate change (such as a rotational movement) to the normal direction 38. Such an operation is difficult and time-consuming, depending on the skill level of the operator.

[0018] Therefore, in the first embodiment, as shown in FIG. 5, the operator designates the direction 42 perpendicular to the work surface 32 of the workpiece 30 (the thinnest direction of the workpiece 30 in this embodiment) or obtains it by the process described later, creates a projection view in which the work surface 32 is projected onto a plane having this direction 42 as the normal vector (that is, a plane parallel to the work surface 32), and designates the bending line on the created projection view. Hereinafter, these processes will be described with reference to the flowchart of FIG. 6.

[0019] First, in step S1, the 3D data of the workpiece 30 stored in the CAD device 18 is divided into an appropriate number of meshes, and a coordinate group of representative points such as the vertices of the meshes is obtained.

[0020] Next, in step S2, as shown in FIG. 7, a work 30, more specifically, an oriented bounding box (hereinafter also referred to as OBB) 44 that includes the acquired vertex coordinate group, is created in a virtual space based on the robot coordinate system 40. The OBB 44 is a rectangular parallelepiped with directionality, and since the OBB 44 itself and its creation method are well-known, detailed description thereof is omitted. The direction of each side of the OBB 44 is represented by the OBB coordinate system 46 set for the OBB 44. In FIG. 7, for clarity, the dimension in the thickness direction of the work 30 (the z direction of the coordinate system 46) is enlarged.

[0021] Next, in step S3, a virtual plane 48 (see FIG. 9 described later) is created with the direction vector of the shortest side of the OBB 44 (the z direction of the OBB coordinate system 46 in the illustrated example) as the normal vector. Here, the z direction of the OBB is the thinnest direction of the work 30 and is also the direction perpendicular to the work surface 32.

[0022] Next, in step S4, the coordinate group acquired in step S1 is projected onto the created plane 48 in the direction of the normal vector (the z direction of the OBB coordinate system 46) to create a projection view 50 as shown in FIG. 8.

[0023] Next, in step S5, an operator or the like inputs and designates the position of the bending line 34 on the projection view 50 displayed on the display 26 via the input unit 24 or the like, and the display 26 displays the designated bending line 34. Finally, in step S6, the position of the bending line 34 designated on the projection view 50 is converted into the position in the virtual space based on the robot coordinate system 40, thereby completing the setting of the bending line. In this way, three-dimensional data of the bending line that can be used when the robot 12 performs bending processing is obtained.

[0024] Among steps S1 - S6, steps other than S5 can be automatically executed by the work support device 16, and S5 is performed based on the input of the operator. However, by setting conditions of the bending line or the like in advance, S5 can also be automatically executed by the processor 20 or the like of the work support device 16.

[0025] In Embodiment 1, by creating a projection view 50 obtained by projecting the 3D model of the workpiece 30 in its thinnest direction, an operator can specify the position of the bending line 34 on the projection view 50. Since the projection view 50 accurately reflects the shape of the work surface 32, even when the directions of the sides of the workpiece 30 do not match the directions of the axes of the robot coordinate system 40, the operator can easily and accurately specify the desired bending line without performing cumbersome operations such as rotating the 3D model.

[0026] Also, if the OBB 44 is used, since the direction vector of the shortest side of the OBB 44 (here, the z direction) coincides with the thinnest direction of the workpiece 30, a projection view 50 suitable for specifying the bending line 34 can be calculated and created more easily.

[0027] FIG. 9 is a schematic diagram showing the positional relationship between the work surface 32 of the workpiece 30 and the plane 48 on which the projection view 50 is created. Even when the thickness of the workpiece 30 is not uniform as shown in FIG. 9, by projecting the vertices of each mesh as shown by points 52, 54, and 56 onto the plane 48 having the direction of the shortest side of the OBB 44 (the z direction of the coordinate system 46) as the normal vector and setting points 58, 60, and 62 on the projection view 50, a projection view suitable for specifying the bending line can be obtained.

[0028] Normally, since the bending line is specified at the thinnest part of the workpiece, in the example of FIG. 9, the bending line can be specified at point 60, but not at points 58 and 62. Therefore, when the thickness is not uniform, by utilizing the fact that the distance between the work surface of the workpiece and the projection view varies depending on the location, based on the distance between each point on the workpiece 30 and the corresponding point on the plane 48 (for example, the distance between point 54 and point 60), each point on the projection view can be visually identified by changing the color, mark shape, etc. In this way, for example, the point 60 at the thin part of the workpiece 30 is displayed in a different color and shape from the points 58 and 62 at the thick part, so that the operator can more clearly grasp which part of the projection view the bending line should be specified.

[0029] Thus, in the first embodiment, the work support device 16 functions as a simulation device configured to execute a bending process simulation and transmit the simulation results to the robot control device 14.

[0030] (Second Embodiment) In the second embodiment, the work support device 16 functions as a device that supports the operation of taking out an article by the robot 12. Here, as shown in FIG. 10, a plurality of workpieces 64 having an elliptical work surface 68 are stacked, and based on the result of detecting these workpieces by a vision sensor (for example, an image captured by a camera), consider the operation of sequentially taking out the workpieces 64 with the robot 12.

[0031] Also in this case, similar to the first embodiment, the workpiece 64 is divided into an appropriate number of meshes to obtain a point group 66 representing representative points such as the vertices of the meshes. Next, the point group 66 is projected onto a virtual plane to create a projection view. However, since the stacked workpieces 64 are inclined, for example, when the point group 66 is projected onto a virtual plane 72 perpendicular to the vertical direction 70, the distances and positional relationships between the points may not be accurately reflected in the obtained projection view.

[0032] Therefore, in the second embodiment, it is preferable to project the point group 66 along the direction 74 onto a virtual plane 76 perpendicular to the normal vector 74 of the work surface (here, the surface held by suction or the like by the hand of the robot 12) 68 (that is, parallel to the work surface 68) to obtain a projection view. In this way, as shown in FIG. 11, a projection view 78 including a point group having the same positional relationship as the point group on the work surface 68 can be obtained, so that the operator can accurately specify which part of the work surface 68 should be the work target part for operations such as suction. Instead of the operator's specification, for example, the centroid position of the work surface 68 can be automatically calculated based on the position of the point group 66 within the projection view 78, and the centroid position can be set as the work target part. Using the position of the work target part obtained in this way, the part of the work surface 68 that the robot 12 should hold can be appropriately determined.

[0033] In Example 2 as well, if the 3D data of the workpiece 64 is stored in advance in the CAD device 18 or the like, the work support device 16 can create an OBB as in Example 1 based on the 3D data and the camera image of the workpiece. In that case, if the workpiece 64 and the point group 66 are projected in the direction perpendicular to the work target surface 68 (for example, the XY plane) of the workpiece 64 among the OBBs (for example, the Z-axis direction), and a projection view parallel to the work target surface 68 is created, the same effect as in Example 1 can be obtained.

[0034] According to the present disclosure, by virtually generating a projection view parallel to the work target surface, settings necessary for various operations by the robot, such as specifying the bending line and the workpiece gripping position, can be performed easily and accurately.

Description of Reference Numerals

[0035] 10 System 12 Robot 14 Robot Control Device 16 Work Support Device 18 Shape Data Storage Device 20 Processor 22 Memory 24 Input Unit 26 Display 30, 64 Workpiece 32, 68 Work Target Surface 34 Bending Line 36, 48, 72, 76 Virtual Plane 38, 42, 74 Normal Vector 40 Robot Coordinate System 44 Oriented Bounding Box 46 OBB Coordinate System 50, 78 Projection View

Claims

1. A projection drawing creation function that projects an object having a work target surface including a bending line on which a robot performs bending work in a direction perpendicular to the work target surface to create a projection drawing parallel to the work target surface in a virtual space; A work part designation function for designating the bending line on the projection drawing; A work part conversion function for converting the position of the bending line designated on the projection drawing into a position in the virtual space; and has The bending line is an intersection line between the object and a virtual plane in the virtual space, and a normal direction of the virtual plane does not coincide with any axial direction of a robot coordinate system in the virtual space. A work support device.

2. An oriented bounding box including the object is created, and the projection drawing is created by projecting the object in a direction of the shortest side of the oriented bounding box. The work support device according to claim 1.

3. A projection drawing creation function that projects an object having a work target surface including a work target part on which a robot performs work in a direction perpendicular to the work target surface to create a projection drawing parallel to the work target surface in a virtual space; A work part designation function for designating the work target part on the projection drawing; A work support device having a work part conversion function for converting the position of the work target part designated on the projection drawing into a position in the virtual space, wherein the work target part on the projection drawing is displayed so as to be visually distinguishable based on a distance between the work target part on the projection drawing and the work target part on the corresponding object. A work support device.

4. The work is a take-out operation of the object, and the work target part is a part where the robot holds the object. The work support device according to claim 3.

5. Projecting an object having a work target surface including a bending line on which a robot performs bending work in a direction perpendicular to the work target surface to create a projection drawing parallel to the work target surface in a virtual space; Designating the bending line on the projection drawing; Converting the position of the bending line designated on the projection drawing into a position in the virtual space; including The bending line is an intersection line between the object and a virtual plane in the virtual space, and a normal direction of the virtual plane does not coincide with any axial direction of a robot coordinate system in the virtual space. A work support method. Item 6. A method for assisting work, comprising: projecting an object having a work target surface including a work target part on which a robot performs work in a direction perpendicular to the work target surface to create a projection view parallel to the work target surface in a virtual space; designating the work target part on the projection view; converting the position of the work target part designated on the projection view into a position in the virtual space; displaying the work target part on the projection view so as to be visually distinguishable based on the distance between the work target part on the projection view and the corresponding work target part on the object; ​

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