Self-interference determination apparatus

Abstract

A self-interference determination device includes a link shape correction section that corrects a link shape based on a specified distance between the link shapes of links of a robot that are considered to have self-interference with each other, and a shape interference determination section that determines whether or not there is self-interference based on the link shape.

Description

Technical Field

[0001] This invention relates to robot control technology, and more particularly to a self-interference determination device for determining self-interference in robots with complex shapes or axis structures. Background Technology

[0002] In robots with multiple links, self-interference sometimes occurs when a link collides with other links while the links are being moved. The robot is controlled to prevent self-interference, and the position or angle of the link at the time of self-interference can be determined using a pre-defined self-interference formula. However, in robots with complex shapes or axis structures, conventional self-interference formulas, which determine the presence or absence of self-interference solely based on the position or angle of a specific link, regardless of the position or angle of links other than that specific link, cannot simply handle all conditions. Furthermore, if a mathematical formula for the self-interference formula is used, the robot's range of motion is sometimes significantly limited. Moreover, the conditional branches of the mathematical formula become excessive and sometimes impractical. The literature described below is known as prior art for determining self-interference in robots.

[0003] Patent Document 1 discloses an interference determination device for a multi-joint robot. The interference determination device includes: an acquisition unit that acquires region information within a configuration space using the rotation angles of two or three specific joints of the multi-joint robot as coordinate axes; region information representing interference regions where self-interference is certain to occur regardless of the rotation angles of joints other than the specific joints, and non-interference regions where interference is certain to occur regardless of the rotation angles of joints other than the specific joints; and a determination unit that determines self-interference by determining whether the coordinates representing the posture determined by the rotation angles of the specific joints belong to either the interference region or the non-interference region. If the coordinates belong to a detailed determination region that is neither an interference region nor a non-interference region, the determination unit determines whether self-interference has occurred based on the shape of multiple links.

[0004] Patent Document 2 discloses an interference detection device for a robot. The interference detection device checks whether there is a possibility of interference between multiple constituent elements of the robot. The interference detection device includes: a primary interference determination unit that determines whether there is a possibility of interference between primary approximation elements by using a first model representing a primary approximation element that includes each of the multiple constituent elements; and a secondary interference determination unit that determines whether there is a possibility of interference between secondary approximation elements by using a second model representing a secondary approximation element that is equal to or smaller than the primary approximation element.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-198914

[0008] Patent Document 2: Japanese Patent Application Publication No. 2011-131303 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] This invention addresses the problems of the past and aims to provide a technology that can determine whether a robot with a complex shape or axis structure has self-interference, even if the position or angle of the links other than the specific link cannot be determined solely by the position or angle of the specific link.

[0011] Methods for solving problems

[0012] One aspect of this disclosure provides a self-interference determination device, comprising: a link shape correction unit that corrects the link shape based on a specified distance between the link shapes of a robot having multiple links in which self-interference occurs between the links; and a shape interference determination unit that determines whether self-interference exists based on the link shape.

[0013] Another aspect of this disclosure provides a self-interference determination device, which includes: a shape interference determination unit, which determines whether there is self-interference for links that cannot be determined based on whether the shapes of the links are close to each other to within a specified distance. The links that cannot be determined are not affected by the position or angle of the links other than the specific link of the robot with multiple links, and the presence or absence of self-interference cannot be determined solely by the position or angle of the specific link.

[0014] Another aspect of this disclosure provides a self-interference determination device comprising: a self-interference definition unit that defines a self-interference type for determining the possibility of self-interference occurring in a robot having multiple links; and a self-interference determination unit that determines the possibility of self-interference based on the self-interference type. The self-interference definition unit defines a self-interference type for links that cannot be determined, based on the shape of the movable area of ​​all links from the root side of the robot to the front side of the robot that cannot be determined, regardless of the position or angle of the links other than the specific link, the presence or absence of self-interference cannot be determined solely by the position or angle of the specific link.

[0015] Another aspect of this disclosure provides a self-interference determination device for determining self-interference between a first link and a second link, comprising: an undeterminable link determination unit, which determines whether either the first link or the second link is an undeterminable link whose self-interference cannot be determined solely by the position or angle of one link when it is considered that self-interference has occurred between the first link and the second link; and an interference determination unit, which determines the self-interference of the undeterminable link based on the determination result.

[0016] Invention Effects

[0017] According to the method disclosed herein, even for robots with complex shapes or axis structures where the presence or absence of self-interference cannot be determined solely by the position or angle of a specific link, regardless of the position or angle of the links other than the specific link, it is still possible to determine whether or not self-interference exists. Attached Figure Description

[0018] Figure 1 This is a schematic structural diagram of a robot system according to one embodiment.

[0019] Figure 2 This is a functional block diagram of a robot system according to one implementation method.

[0020] Figure 3 This is a 3D diagram of a robot representing an example of a self-interference definition method.

[0021] Figure 4 This is a geometric diagram of a robot representing an example of a self-interference definition method.

[0022] Figure 5A It is a 3D diagram representing a robot with a linkage shape magnified by a specified distance.

[0023] Figure 5B It is a 3D diagram representing a robot with a simplified link shape that converges to a specified range.

[0024] Figure 6 This is a flowchart illustrating an example of the preprocessing of a self-interference determination device.

[0025] Figure 7 This is a flowchart illustrating an example of the determination process of a self-interference determination device.

[0026] Figure 8 This is a functional block diagram of a robot system with other implementation methods. Detailed Implementation

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same or similar constituent elements are labeled with the same or similar reference numerals. Furthermore, the embodiments described below do not limit the technical scope of the invention described herein or the meaning of the terms used. In this specification, the term "link" refers to a connecting component in a single-axis or multi-axis robot. It should be noted that, for example, "link" includes not only the robot's arm but also tool parts such as hands, screwdrivers, and welding torches. In this specification, the term "self-interference" refers to links interfering with each other. Furthermore, it should be noted that in this specification, the term "interference" refers to the calculation of shape interference based on the shape of the link, encompassing not only contact between objects but also intersections between objects. Additionally, it should be noted that in this specification, the term "rotation" includes both clockwise and counterclockwise rotation.

[0028] First, the structure of the robot system in this embodiment will be described. Figure 1 This is a schematic diagram of robot system 1. Robot system 1 includes: robot 10, which has multiple links; and self-interference detection device 20, which determines whether self-interference exists. Robot 10 is, for example, a collaborative robot with a complex shape or axis structure. Robot 10 has a first link 11, a second link 12, a third link 13, a fourth link 14, a fifth link 15, a sixth link 16, and a seventh link 17. For example, the first links 11 to the sixth links 16 are the arm part of robot 10, and the seventh link 17 is the tool part (e.g., a hand). These multiple links are connected in series.

[0029] The first link 11 to the sixth link 16 are connected to each other, for example, by gears such as a reducer. The sixth link 16 and the seventh link 17 are fastened together, for example, by bolts or screws. The first link 11 rotates about axis J1, the second link 12 rotates about axis J2, the third link 13 rotates about axis J3, the fourth link 14 rotates about axis J4, the fifth link 15 rotates about axis J5, and the sixth link 16 and the seventh link 17 rotate together about axis J6. The first link 11 to the seventh link 17 are driven by a drive source (not shown) such as a servo motor.

[0030] The robot 10 has a complex shape or axis structure with no other links (e.g., links 13 to 17) at the center of rotation on a virtual plane (e.g., the XZ plane or YZ plane) containing the axis J1 of the first link 11. Furthermore, the third link 13 rotates 360° about axis J3, and the fourth link 14 rotates 360° about axis J4. Therefore, links 15 to 17, located closer to the front end of the robot 10 than the fourth link 14, may interfere with the first link 11 or the second link 12.

[0031] In contrast, a typical vertical articulated robot, for example, has a simple shape or axis structure with rotational centers of other links existing on a virtual plane containing the axis J1 of the first link. Therefore, regardless of the position or angle of links other than the specific link, the presence or absence of self-interference can be easily determined by judging the position or angle of the specific link alone. However, in robots with… Figure 1 In a robot 10 with a complex shape or axis structure as shown, it is impossible to determine whether the fifth link 15, the sixth link 16, and the seventh link 17 interfere with the first link 11 or the second link 12 only at specific positions or angles. The self-interference determination device 20 can determine whether self-interference exists even in a robot 10 with such a complex shape or axis structure.

[0032] The self-interference determination device 20 is, for example, a robot control device. Although not shown, the self-interference determination device 20 may be, for example, a computer device equipped with a processor, memory, input / output units, etc. The processor may include, for example, a CPU (central processing unit). The memory may include, for example, RAM (random access memory), ROM (read-only memory), etc. The memory may store, for example, programs executed by the processor, and various data used or generated by the processor. The input / output units input or output various data used or generated by the processor.

[0033] First, the self-interference determination device 20 defines a conventional self-interference method that determines the presence or absence of self-interference solely by the position or angle of the specific link, regardless of the position or angle of the links other than the specific link (hereinafter referred to as "determinable link"). However, it should be noted that in Figure 1 In the robot 10 shown, there are no identifiable links that may have self-interference capabilities.

[0034] On the other hand, the self-interference determination device 20 defines a self-interference formula for links (hereinafter referred to as "undeterminable links") for which self-interference cannot be determined solely by the position or angle of the specific link, regardless of the position or angle of the links other than the specific link. This formula is based on the shape of the movable area of ​​all links, from the undeterminable link (e.g., the fifth link 15) on the root side of the robot 10 to the undeterminable link (e.g., the seventh link 17) on the front side of the robot 10. For example, in Figure 1In the robot 10 shown, links 15 through 17 are links that cannot be determined. The self-interference type is defined based on the shape of the motion range of all links from the fifth link 15 at the root side of the robot to the seventh link 17 at the front side of the robot. Then, the self-interference determination device 20 roughly determines the possibility of self-interference based on the self-interference type (hereinafter referred to as "self-interference type determination" or "probability determination").

[0035] Furthermore, for identifiable links, the self-interference determination device 20 determines the presence or absence of self-interference using a self-interference method. However, for links that cannot be determined, the self-interference determination device 20 makes a detailed determination of whether self-interference exists based on whether the shapes of the links are close to each other within a specified distance (hereinafter referred to as "shape interference determination" or "detailed determination"). For example, in Figure 1 In the robot 10 shown, detailed determinations based on shape interference determination are performed on the fifth to seventh links 17, which are links that cannot be determined. This prevents the robot 10's range of motion from being limited. In other words, the self-interference determination device 20 has a hybrid determination function that combines a general determination based on self-interference determination with a detailed determination based on shape interference determination.

[0036] Figure 2 This is a functional block diagram of robot system 1. It should be noted that the "~component" in the self-interference determination device 20 refers to a functional module implemented, for example, by a program executed by a processor. The self-interference determination device 20 includes a self-interference definition unit 21, a self-interference determination unit 22, and a robot control unit 29. The self-interference definition unit 21 defines a self-interference pattern for determining the likelihood of self-interference occurring in robot 10, and the self-interference determination unit 22 determines the likelihood of self-interference based on the defined self-interference pattern. The robot control unit 29 controls the drive source 18 of robot 10, and the drive source 18 provides the robot control unit 29 with the current state of the link (i.e., the current position or angle, speed, etc.). The robot control unit 29 provides the self-interference determination unit 22 with the current state of the link. The self-interference determination unit 22 determines the likelihood of self-interference by substituting the provided current position or angle of the link into the self-interference pattern.

[0037] Figure 3This is a perspective view of a robot 10 illustrating an example of a self-interference definition method. For example, in the case of defining a self-interference method where the fifth link 15 to the seventh link 17 are links that cannot be determined, the self-interference definition unit 21 first causes all links from the fourth link 14 (located closer to the root of the robot 10 than the fifth link 15) to the seventh link 17 (located at the front of the robot 10) to move, defining cylinders 15-17 that include the movable regions of all links from the fifth link 15 (root side of the robot 10) to the seventh link 17 (front side of the robot 10). Alternatively, the self-interference definition unit 21 can also obtain the link shapes of the fifth link 15 to the seventh link 17 from the link shape acquisition unit 25 (described later).

[0038] Next, the self-interference definition unit 21 defines a self-interference type that determines the possibility of interference between, for example, the second link 12 and the cylinder 15-17, which includes the movable area of ​​the fifth link 15 to the seventh link 17, which are links that cannot be determined. Figure 4 This is a geometric diagram of robot 10, representing an example of a self-interference definition method. It should be noted that, for ease of understanding, in... Figure 4 Only the second link 12, the third and fourth links 13-14, and the cylinder 15-17 are depicted in a simplified manner.

[0039] Here, the base point of the second link 12 is set as P1, the rotation center of the third link 13 is set as P2, the center of cylinder 15-17 is set as P3, the nearest point of cylinder 15-17 to the second link 12 is set as P4, and the intersection of the perpendicular line drawn from the center P3 of cylinder 15-17 to the center line of the second link 12 and the center line of the second link 12 is set as P5. Furthermore, the length of line segment P2P3 is set as L1, the length of line segment P3P4 is set as L2, the current angle of the third link 13 is set as θ1, and the current angle of the fifth link 15 (the angle between line segments P2P3 and P3P4) is set as θ2.

[0040] At this point, the angle between the perpendicular line P3P5 and line segment P3P4 is θ1+θ2-90°. Therefore, the magnitude of the direction of cylinder 15-17 toward the second link 12 is expressed as L2cos(θ1+θ2-90°). Furthermore, the magnitude of the direction of the second link 12 toward cylinder 15-17 is set as R1. On the other hand, the distance between cylinder 15-17 and the second link 12 is expressed as L1sinθ1. Therefore, if the distance L1sinθ1 between cylinder 15-17 and the second link 12 is less than the sum of the magnitude of cylinder 15-17 toward the second link 12 (L2cos(θ1+θ2-90°)) and the magnitude of the second link 12 toward cylinder 15-17 (R1), then cylinder 15-17 (i.e., the fifth to seventh links 17, which are links whose direction cannot be determined) may interfere with the second link 12. That is, the self-interference formula for determining the possibility of self-interference between the link (fifth link 15 to seventh link 17) and the second link 12 is as follows.

[0041] [Formula 1]

[0042] L1sinθ1≤L2cos(θ1+θ2-90°)+R1···Equation 1

[0043] Here, since L1, L2, and R1 are constants, if the current angle θ1 of the third link 13 and the current angle θ2 of the fifth link 15 are substituted into the self-interference formula of Equation 1, it can be determined that the possibility of self-interference between the links (fifth link 15 to seventh link 17) and the second link 12 cannot be determined. The self-interference formula definition unit 21 also defines the self-interference formula using the same principle for other combinations of links that may cause self-interference (e.g., fifth link 15 to seventh link 17 and first link 11).

[0044] Refer again Figure 2 The robot control unit 29 provides the current state of the links (i.e., the current position or angle) to the self-interference determination unit 22. The self-interference determination unit 22 substitutes the current state of the links into the self-interference equation to determine whether there is a possibility of self-interference. For example, the self-interference determination unit 22 substitutes the current angle θ1 of the third link 13 and the current angle θ2 of the fifth link 15 into the self-interference equation of Equation 1 to perform a self-interference determination (approximate determination).

[0045] The self-interference determination device 20 may also include an undeterminable link definition unit 23 and an undeterminable link determination unit 24. The undeterminable link definition unit 23 defines undeterminable links that may have self-interference, and the undeterminable link determination unit 24 determines whether the undeterminable link has the possibility of actual self-interference.

[0046] The "Undeterminable Link" definition section 23 defines, for example, links 15 to 17 as "undeterminable links." That is, links 15 to 17 are links that have the potential to self-interfere with links 11 or 12, and whose self-interference cannot be determined solely by their position or angle. In other words, links 15 to 17 are links that do not have a center of rotation on a virtual plane containing the axis J1 of link 11.

[0047] The link determination unit 24 determines, for example, whether the fifth to seventh links 17, which are undeterminable links, have the potential to actually interfere with the first link 11 or the second link 12. Specifically, the link determination unit 24 determines whether the links that the self-interference determination unit 22 determines to have the potential to interfere are the defined undeterminable links (fifth to seventh links 17).

[0048] If the link that is determined to have a potential for self-interference by the self-interference method is not a link that cannot be determined but a link that can be determined, then since the link that cannot be determined can be accurately determined by the self-interference method, the link determination unit 24 sends a stop command to the robot control unit 29 for the robot 10. The robot control unit 29 then stops the drive source 18 of the robot 10 based on the stop command.

[0049] Alternatively, if the link that is determined to have a possibility of self-interference by the self-interference method is a link that cannot be determined by definition, the link determination unit 24 cannot send a shape interference determination command to the shape interference determination unit 28 because the self-interference method cannot accurately determine whether a link has self-interference. The self-interference determination device 20 also includes a link shape acquisition unit 25, a specified distance acquisition unit 26, a link shape correction unit 27, and a shape interference determination unit 28.

[0050] Link shape acquisition unit 25 acquires the link shape, designated distance acquisition unit 26 acquires the designated distance between link shapes considered to interfere with each other, link shape correction unit 27 corrects the link shape based on the designated distance, and shape interference determination unit 28 determines in detail whether there is self-interference based on whether the link shapes are close to each other to within a designated distance. Robot control unit 29 provides the shape interference determination unit 28 with the current state of the link (i.e., current position or angle, speed, etc.). Shape interference determination unit 28 calculates the current position and posture of the link shape based on the provided current position or angle of the link.

[0051] The link shape acquisition unit 25 acquires, for example, the link shapes of the first link 11, the second link 12, the fifth link 15, the sixth link 16, and the seventh link 17, which may have self-interference potential. Alternatively, the link shape acquisition unit 25 may acquire all the link shapes of the first link 11 to the seventh link 17. For example, the link shapes may be three-dimensional data such as three-dimensional CAD (computer-aided design) data or three-dimensional polygon data. The link shape acquisition unit 25 may acquire the link shapes from a memory or an external device, for example.

[0052] The specified distance acquisition unit 26 acquires, for example, a specified distance of 50 mm between the link shapes considered to be causing self-interference between the second link 12 and the fifth link 15. Therefore, when the second link 12 and the fifth link 15 approach to within 50 mm of the specified distance, self-interference is considered to have occurred, and the robot 10 can be stopped. Alternatively, the specified distance can also be specified as a range. In this case, the specified distance acquisition unit 26 acquires, for example, a range of 50 mm to 70 mm between the link shapes considered to be causing self-interference between the second link 12 and the fifth link 15. Therefore, when the second link 12 and the fifth link 15 approach to within the specified range of 50 mm to 70 mm, self-interference is considered to have occurred, and the robot 10 can be stopped. The specified distance acquisition unit 26 acquires the specified distance, for example, from a memory or an external device.

[0053] The link shape correction section 27, for example, expands the link shape by a specified distance. Figure 5A This is a perspective view of the robot 10 showing the link shape 15a expanded by a specified distance. The link shape 15a is obtained by expanding the actual link shape of the fifth link 15 by a specified distance of 50 mm. Alternatively, when a specified distance is specified in the range, the link shape correction unit 27 can be simplified, for example, to converge the link shape within the specified range. Figure 5B This is a perspective view of a robot 10 showing a simplified link shape 15b that converges to a specified range. The link shape 15b is obtained by simplifying the actual link shape of the fifth link 15 within a specified range of 50mm to 70mm. The link shape 15b is simplified using two cylinders 30 and 31 and a sphere 32. Alternatively, the link shape can be simplified using a cylinder or a sphere, as long as it converges to the specified range of 50mm to 70mm.

[0054] In addition, the link shape correction unit 27 also expands the specified distance or simplifies the connection to a specified range for other links that cannot be determined, such as the sixth link 16 and the seventh link 17.

[0055] Refer again Figure 2The shape interference determination unit 28 determines, for example, whether the enlarged link shape 15a of the fifth link 15 interferes with (contacts or intersects with) the link shape of the second link 12. For example, when using three-dimensional polygon data, the contact or intersection of polygon faces can be determined by looping. For example, if one or more vertices of one polygon face are located on the back side of another polygon face, and the remaining vertices are located on the front side of another polygon face, it can be determined that the link shapes interfere with each other. Such shape interference determination is computationally more efficient than the method of determining whether the distance between polygon faces is less than a specified distance by looping.

[0056] Alternatively, the shape interference determination unit 28 may determine, for example, whether the simplified link shape 15b of the fifth link 15 interferes with (contacts or intersects with) the link shape of the second link 12. For example, when using three-dimensional polygon data, the simplified link shape 15b has an overwhelmingly smaller number of polygon faces compared to the enlarged link shape 15a. Therefore, shape interference determination based on the simplified link shape 15b is more computationally efficient than shape interference determination based on the enlarged link shape 15a.

[0057] If, based on this shape interference determination (detailed determination), a self-interference is determined to exist, the shape interference determination unit 28 sends a stop command to the robot control unit 29 for the robot 10. The robot control unit 29 then stops the drive source 18 of the robot 10 based on the stop command. Alternatively, if, based on the shape interference determination (detailed determination), a self-interference determination unit 28 sends a determination command to the self-interference determination unit 22 and returns to the self-interference determination (general determination), or repeats the shape interference determination (detailed determination).

[0058] Furthermore, the self-interference determination device 20 may also include a robot stop command unit (not shown), which calculates the current shortest distance between the links and the current relative speed between the links, and determines whether the robot 10 can be safely (gently) stopped based on the shortest distance and relative speed. If it is determined that the robot 10 can be safely stopped, a safe stop command is sent to the robot control unit 29. The robot stop command unit may also send an emergency stop command to the robot control unit 29 if it is determined that the robot 10 cannot be safely stopped.

[0059] Figure 6This is a flowchart illustrating an example of the preprocessing of the self-interference determination device 20. This flowchart is executed, for example, by the processor of the self-interference determination device 20. In step S10, links that cannot be determined based solely on the position or angle of a specific link are defined as undeterminable links. For example, links 15 to 17 are identified as undeterminable links via user input through a graphical user interface (GUI).

[0060] In step S11, a self-interference formula is defined for determining the possibility of self-interference between the links. For example, a conventional self-interference formula is defined for links that can be determined, while for links 15 to 17 that cannot be determined, a self-interference formula is defined based on the shape of the movable area of ​​all links from the root side of the robot 10 to the front side of the robot 10.

[0061] In step S12, the link shape is obtained. For example, the link shape is input from memory or an external device. In step S13, a specified distance between the link shapes that are considered to be interfering with each other is obtained. For example, a specified distance of 50 mm is input via the GUI through user operation. In step S14, the link shape is corrected based on the specified distance. For example, the link shape of the fifth link 15 is expanded by the specified distance of 50 mm, or, if the specified distance is specified as a range, the link shape of the fifth link 15 is simplified to converge within the specified range of 50 mm to 70 mm.

[0062] In addition, it should be noted that, Figure 6 In the flowchart shown, the order of steps S10-S11 and S12-S14, and the order of steps S12 and S13, can also be reversed.

[0063] Figure 7 This is a flowchart illustrating an example of the determination process of the self-interference determination device 20. This flowchart is executed, for example, by the processor of the self-interference determination device 20. Note that this flowchart is executed during the operation of the robot 10. In step S20, the possibility of self-interference is determined based on self-interference criteria (i.e., a self-interference determination (preliminary determination) is performed). If the self-interference determination indicates that there is no possibility of self-interference ("No" in step S20), the self-interference determination (preliminary determination) in step S20 is repeated.

[0064] If self-interference is deemed possible through the self-interference method ("Yes" in step S20), in step S21, it is determined whether the link deemed to have a possibility of self-interference through the self-interference method is an undeterminable link. If the link deemed to have a possibility of self-interference through the self-interference method is a determinable link ("No" in step S21), the robot 10 is stopped in step S23 because self-interference exists. At this time, the current shortest distance between the link shapes and the current relative speed between the link shapes can also be calculated, and the robot 10 is safely stopped based on the shortest distance and relative speed.

[0065] If a link that is deemed to have a potential for self-interference cannot be determined by the self-interference method ("Yes" in step S21), in step S22, the presence or absence of self-interference is determined based on whether the link shapes are close to each other within a specified distance (i.e., shape interference determination (detailed determination) is performed). For example, it is determined whether the link shape that has been increased by a specified distance interferes with other link shapes (contacts or crosses). Alternatively, if a specified distance is specified by a range, it is determined whether the simplified link shape within the specified range interferes with other link shapes (contacts or crosses).

[0066] If it is determined that the link shapes do not interfere with each other (No in step S22), the process returns to the self-interference determination in step S20. Alternatively, the shape interference determination in step S22 can be performed repeatedly. If it is determined that the link shapes interfere with each other (Yes in step S22), the robot 10 is stopped in step S23 due to the existence of self-interference. At this time, the current shortest distance between the link shapes and the current relative speed between the link shapes can also be calculated, and the robot 10 can be safely stopped based on the shortest distance and relative speed.

[0067] The self-interference determination device 20 mentioned above may also be configured not as a robot control device, but as a host computer device that sends various instructions to the robot control device. Figure 8 This is a functional block diagram of robot system 1 in another embodiment. Robot system 1 includes a self-interference determination device 20, multiple robot control devices 40, and multiple robots 10. The current state of the links of each robot 10 (e.g., current position or angle, speed, etc.) is converged to the self-interference determination device 20 via each robot control device 40.

[0068] The self-interference determination device 20 performs self-interference determination (approximate determination) and shape interference determination (detailed determination) based on the current state of the links of each robot 10 (current position or angle, speed, etc.). If self-interference is determined to exist, the self-interference determination device 20 sends a stop command to each robot control device 40. Each robot control device 40 then stops the drive source 18 of each robot 10 based on the stop command.

[0069] It should be noted that the structure of the robot system 1 and the self-interference determination device 20 described above is just one example, and other structures can also be used. For example, robot 10 may not be an industrial robot, but a humanoid robot or other types of robot. In addition, robot 10 may not have multiple links connected in series, and shape interference determination may be applied to robots with multiple links connected in parallel (such as dual-arm robots). Furthermore, the seventh link 17 of robot 10 may not be a hand, but a tool part such as a screwdriver, welding tool, or sealing tool.

[0070] Alternatively, the self-interference determination device 20 may not have a processor that executes programs, but instead has an integrated circuit that does not execute programs (such as an FPGA (field-programmable gate array), ASIC (application-specific integrated circuit), etc.). This integrated circuit has... Figure 2 The “~” section is shown. Furthermore, Figure 6 and Figure 7 The flowchart shown may also be executed by the integrated circuit instead of the processor. Furthermore, the self-interference determination device 20 may not have a hybrid determination function such as self-interference determination (general determination) and shape interference determination (detailed determination), but may only have a shape interference determination function.

[0071] Furthermore, the link shape correction unit 27 may, for example, not expand the link shape of the fifth link 15, which is an undeterminable link, by a specified distance, but instead expand the link shape of the first link 11 or the second link 12, which may have self-interference with the fifth link 15. Alternatively, if within the specified distance, the link shape of the fifth link 15 and the link shape of the first link 11 or the second link 12 may be expanded separately. Similarly, when the specified distance is specified by a range, the link shape correction unit 27 may, for example, not simplify the link shape of the fifth link 15, which is an undeterminable link, to converge within the specified range, but instead simplify the link shape of the first link 11 or the second link 12, which may have self-interference with the fifth link 15, or if within the specified range, the link shape of the fifth link 15 and the link shape of the first link 11 or the second link 12 may be simplified separately.

[0072] Furthermore, the self-interference determination device 20 may also include an interference determination unit. When the links are considered to be interfering with each other based on self-interference, even if any of these links is a link that cannot be determined to have self-interference based solely on its position or angle, if self-interference can be determined based on the position or angle of the other link, the interference determination unit will not perform shape interference determination, but will determine the self-interference of the link that cannot be determined solely based on the position or angle of the other link.

[0073] The program executed by the aforementioned processor, other integrated circuits, etc., or the program executing the aforementioned flowchart, may be provided by recording on a computer-readable non-transient recording medium, such as a CD-ROM, or may be provided by distributing via wired or wireless means from a server device on a WAN (wide area network) or LAN (local area network).

[0074] Various embodiments have been described in this specification, but the present invention is not limited to the embodiments described above, and it should be recognized that various modifications can be made within the scope of the claims.

[0075] Symbol Explanation

[0076] 1. Robot system;

[0077] 10 robots;

[0078] 11. First link;

[0079] 12. Second link;

[0080] 13. Third link;

[0081] 14. Fourth link;

[0082] 15. Fifth link;

[0083] 15a Enlarged link shape;

[0084] 15b Simplified link shape;

[0085] 16. Sixth link;

[0086] 17. Seventh link;

[0087] 18 driving sources;

[0088] 13-14 Third and fourth links;

[0089] 15-17 Cylinders;

[0090] 20 Self-interference detection device;

[0091] 21. Self-interference definition section;

[0092] 22 Self-interference determination unit;

[0093] 23. The link definition cannot be determined;

[0094] 24. The linkage determination unit cannot be determined.

[0095] 25. Linkage shape acquisition part;

[0096] 26. Obtain the unit at a specified distance;

[0097] 27. Linkage shape correction section;

[0098] 28. Shape interference determination unit;

[0099] 29. Robot Control Department;

[0100] 30, 31 cylinders;

[0101] 32 sphere;

[0102] J1~J6 axis.

Claims

1. A self-interference determination device, characterized in that, have: The link shape correction unit corrects the link shape based on a specified distance between the links of a robot with multiple links, where the links interfere with each other. The shape interference determination unit determines whether there is self-interference based on the shape of the connecting rod; as well as The robot stop command unit calculates the current shortest distance between the links and the current relative speed between the links, and sends a safety stop command to bring the robot to a safe stop based on the shortest distance and the relative speed.

2. The self-interference determination device according to claim 1, characterized in that, The link shape correction section expands the link shape by the specified distance.

3. The self-interference determination device according to claim 1 or 2, characterized in that, When the specified distance is specified by a range, the link shape correction unit simplifies the link shape by converging the link shape within the specified range.

4. A self-interference determination device, characterized in that, It includes: a shape interference determination unit, which determines whether there is self-interference for links that cannot be determined based on whether the shapes of the links are close to each other to a specified distance or less. Regardless of the position or angle of the links other than the specific link of the robot with multiple links, it is impossible to determine whether there is self-interference based solely on the position or angle of the specific link. as well as The robot stop command unit calculates the current shortest distance between the links and the current relative speed between the links, and sends a safety stop command to bring the robot to a safe stop based on the shortest distance and the relative speed.

5. The self-interference determination device according to claim 1 or 4, characterized in that, The self-interference determination device also includes a designated distance acquisition unit for acquiring the designated distance.

6. The self-interference determination device according to claim 1 or 4, characterized in that, The self-interference determination device also includes a link shape acquisition unit for acquiring the link shape.

7. A self-interference determination device, characterized in that, have: The self-interference definition section defines a self-interference type that determines the probability of self-interference occurring in a robot with multiple links; and The self-interference determination unit determines the likelihood of self-interference based on the self-interference pattern. The self-interference definition unit defines the self-interference type for undeterminable links based on the shape of the movable area of ​​all links from the undeterminable link on the root side of the robot to the undeterminable link on the front side of the robot. Regardless of the position or angle of the links other than the specific link, the presence or absence of self-interference cannot be determined solely by the position or angle of the specific link.

8. The self-interference determination device according to claim 7, characterized in that, The self-interference determination device also includes: The link definition cannot be determined, and its definition may cause self-interference; and the link that cannot be determined. The link determination unit cannot determine whether there is a possibility that the link that cannot be determined is actually experiencing self-interference.

9. A self-interference determination device, which determines the self-interference between a first link and a second link, characterized in that, The self-interference determination device includes: The link determination unit cannot determine whether either the first link or the second link is a link that cannot be determined to have self-interference if it considers that the first link and the second link are interfering with each other. as well as The interference determination unit determines the self-interference of the undeterminable link based on the determination result.

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