Self-interference detection device

Abstract

This self-interference determination device is provided with a link shape correction unit that corrects link shapes on the basis of a specified distance between link shapes at which links of a robot comprising a plurality of links are regarded as having undergone self-interference, and a shape interference determination unit that determines the presence or absence of self-interference on the basis of the link shapes.

Description

[Technical field]

[0001] The present invention relates to a robot control technology, and more particularly to a self-interference determination device for determining self-interference of a robot having a complex shape or axis structure. [Background technology]

[0002] In a robot having a plurality of links, when the links are operated, self-interference may occur, in which a certain link collides with another link. The robot is controlled so that self-interference does not occur, and the position or angle of the link when self-interference occurs can be determined by a predetermined self-interference formula. However, in a robot having a complex shape or axis structure, the conventional self-interference formula, which determines the presence or absence of self-interference only from the position or angle of a specific link regardless of the position or angle of links other than the specific link, cannot easily handle all conditions. Furthermore, if an attempt is made to handle it using a formula for the self-interference formula, the operating range of the robot may be significantly limited. Furthermore, the formula may have too many conditional branches and may not be practical. The documents described below are known as prior art for determining self-interference of a robot.

[0003] Patent Document 1 discloses an interference determination device for an articulated robot. The interference determination device includes an acquisition unit that acquires area information representing an interference area in which self-interference always occurs regardless of the rotation angle of joints other than the specific joints and a non-interference area in which no interference occurs regardless of the rotation angle of joints other than the specific joints in a configuration space having the rotation angles of two or three specific joints of the articulated robot as coordinate axes, and a determination unit that determines whether a coordinate representing a posture determined by the rotation angle of the specific joint belongs to the interference area or the non-interference area to determine self-interference. If the coordinate belongs to a detailed determination area that does not belong to either the interference area or the non-interference area, the determination unit determines whether self-interference occurs based on the shapes of multiple links.

[0004] Patent Document 2 discloses an interference check device for a robot. The interference check device checks whether there is a possibility of interference between multiple components of the robot. The interference check device includes a primary interference determination unit that determines whether there is a possibility of interference between primary approximation elements in a first model expressed as primary approximation elements including each of the multiple components, and a secondary interference determination unit that determines whether there is a possibility of interference between secondary approximation elements in a second model expressed as secondary approximation elements equal to or smaller than the primary approximation elements. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-198914 A [Patent Document 2] JP 2011-131303 A Summary of the Invention [Problem to be solved by the invention]

[0006] In consideration of the problems of the conventional technology, the present invention aims to provide a technology capable of determining the presence or absence of self-interference even in a robot having a complex shape or axis structure in which the presence or absence of self-interference cannot be determined based only on the position or angle of a specific link, regardless of the positions or angles of links other than the specific link. [Means for solving the problem]

[0007] One aspect of the present disclosure is At least one memory that stores information about a plurality of links of the robot, and at least one processor, the at least one processor performing, based on the information about the links, The position or angle of one of the links From Indeterminable links where the presence or absence of self-interference cannot be determined Define the following, judge whether the undeterminable link self-interferes, and if it is judged that the link self-interferes, Based on the specified distance between the link shapes that are considered to be self-colliding, judgment Fixed link shape for indeterminable links death, Based on the corrected link shape, the presence or absence of self-interference of the undeterminable link is judged. execute a process, A self-interference determination device is provided. Another aspect of the present disclosure is a self-interference equation definition unit that defines a self-interference equation for determining a possibility that a robot having a plurality of links self-interferes; Defined by the self-interference equation definition part and a self-interference equation determination unit that determines the possibility of self-interference based on the self-interference equation, wherein the self-interference equation definition unit defines the self-interference equation for an undeterminable link for which the presence or absence of self-interference cannot be determined from the position or angle of a specific link regardless of the positions or angles of links other than the specific link, based on a shape that encompasses the movable areas of all links from the undeterminable link on the root side of the robot to the undeterminable link on the tip side of the robot. Yet another aspect of the present disclosure is a first link and a second link A robot with multiple links, including A self-interference determination device for determining self-interference of Based on information about multiple links, An indeterminable link in which it is not possible to determine whether or not one of the first and second links has self-interference based on the position or angle of the other link. The undeterminable link definition part defines the undeterminable link, and the undeterminable link defined by the undeterminable link definition part may actually self-interfere. an undeterminable link determination unit that determines whether or not there is an undeterminable link; By the undetermined link determination unit The present invention provides a self-interference determination device including an interference determination unit that determines self-interference of an undeterminable link based on a result of the determination. Effect of the Invention

[0008] According to an aspect of the present disclosure, it is possible to determine the presence or absence of self-interference even for robots with complex shapes or axis structures in which the presence or absence of self-interference cannot be determined based solely on the position or angle of a specific link, regardless of the position or angle of links other than the specific link. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of a robot system according to an embodiment. [Diagram 2] FIG. 1 is a functional block diagram of a robot system according to an embodiment. [Diagram 3] FIG. 1 is a perspective view of a robot illustrating an example of a self-interference type definition method. [Figure 4] FIG. 1 is a geometric diagram of a robot illustrating an example of a self-interference definition method. [Figure 5A]FIG. 13 is a perspective view of the robot showing the link shape enlarged by a specified distance. [Figure 5B] FIG. 1 is a perspective view of a robot showing a link shape simplified to fall within a specified range. [Figure 6] 10 is a flowchart showing an example of pre-processing of the self-interference determination device. [Figure 7] 10 is a flowchart showing an example of a determination process of the self-interference determination device. [Figure 8] FIG. 11 is a functional block diagram of a robot system according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In each drawing, the same or similar components are given the same or similar reference numerals. In addition, the embodiments described below do not limit the technical scope of the invention described in the claims and the meaning of the terms. In this specification, the term "link" means a connecting member in a single-axis robot or a multi-axis robot. For example, it should be noted that "link" includes not only the arm part of a robot but also tool parts such as a hand, a driver, and a welding gun. In addition, in this specification, the term "self-interference" means that links interfere with each other. Furthermore, in this specification, it should be noted that the term "interference" means not only contact between objects but also intersection between objects in the calculation of shape interference judgment based on the link shape. In addition, in this specification, it should be noted that the term "rotation" means both forward and reverse rotation.

[0011] First, the configuration of the robot system of this embodiment will be described. Fig. 1 is a schematic diagram of the robot system 1. The robot system 1 includes a robot 10 having a plurality of links, and a self-interference determination device 20 that determines the presence or absence of self-interference. The robot 10 is, for example, a collaborative robot having a complex shape or shaft structure. The robot 10 includes 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 link 11 to the sixth link 16 are the arm portion of the robot 10, and the seventh link 17 is a tool portion (for example, a hand). These multiple links are connected in series.

[0012] The first link 11 to the sixth link 16 are connected to each other by gears such as a reducer. The sixth link 16 and the seventh link 17 are fastened to each other by screws such as bolts. The first link 11 rotates about the axis J1, the second link 12 rotates about the axis J2, the third link 13 rotates about the axis J3, the fourth link 14 rotates about the axis J4, the fifth link 15 rotates about the axis J5, and the sixth link 16 and the seventh link 17 rotate together about the axis J6. The first link 11 to the seventh link 17 are driven by a drive source (not shown) such as a servo motor.

[0013] This robot 10 has a complex shape or axis structure in which the centers of rotation of other links (e.g., the third link 13 to the seventh link 17) do not exist on a virtual plane (e.g., the XZ plane or the YZ plane) that includes the axis J1 of the first link 11. In addition, since the third link 13 rotates 360° around the axis J3 and the fourth link 14 rotates 360° around the axis J4, the fifth link 15 to the seventh link 17, which are located closer to the tip of the robot 10 than the fourth link 14, may interfere with the first link 11 or the second link 12.

[0014] In contrast, for example, a typical vertical articulated robot has a simple shape or axis structure in which the centers of rotation of other links exist on a virtual plane including the axis J1 of the first link, and therefore self-interference can be easily determined using a self-interference method that determines the presence or absence of self-interference only from the position or angle of a specific link, regardless of the positions or angles of links other than the specific link. However, in a robot 10 having a complex shape or axis structure as shown in Figure 1, it is not possible to determine whether the fifth link 15, the sixth link 16, and the seventh link 17 will self-interfere with the first link 11 or the second link 12 only from the position or angle of the specific link. The self-interference determination device 20 can determine the presence or absence of self-interference even in a robot 10 having such a complex shape or axis structure.

[0015] 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, a memory, an input / output unit, etc. The processor is equipped with, for example, a central processing unit (CPU). The memory is equipped with, for example, a random access memory (RAM), a read only memory (ROM), etc. The memory stores, for example, programs executed by the processor and various data used or generated by the processor. The input / output unit inputs or outputs various data used or generated by the processor.

[0016] First, the self-interference determination device 20 defines a conventional self-interference formula for determining the presence or absence of self-interference only from the position or angle of a specific link for links (hereinafter referred to as "determinable links") where the presence or absence of self-interference can be determined only from the position or angle of the specific link, regardless of the positions or angles of links other than the specific link. However, it should be noted that in the robot 10 shown in FIG. 1, there is no determinable link that may self-interfere.

[0017] On the other hand, for links for which the presence or absence of self-interference cannot be determined based on the position or angle of a specific link alone, regardless of the positions or angles of links other than the specific link (hereinafter referred to as "undeterminable links"), the self-interference determination device 20 defines a self-interference equation for determining the possibility of self-interference based on a shape that includes the movable ranges of all links from the undeterminable link at the base side of the robot 10 (e.g., the fifth link 15) to the undeterminable link at the tip side of the robot 10 (e.g., the seventh link 17). For example, in the robot 10 shown in FIG. 1, the fifth link 15 to the seventh link 17 are undeterminable links, and the self-interference equation is defined based on a shape that includes the movable ranges of all links from the fifth link 15 at the base side of the robot to the seventh link 17 at the tip side of the robot. Then, the self-interference determination device 20 roughly determines the possibility of self-interference based on the self-interference equation (hereinafter referred to as "self-interference equation determination" or "rough determination").

[0018] Furthermore, the self-interference determination device 20 determines the presence or absence of self-interference for links that can be determined by the self-interference method, but for links that cannot be determined, it performs a detailed determination of the presence or absence of self-interference based on whether the link shapes have approached each other to within a specified distance (hereinafter referred to as "geometric interference determination" or "detailed determination"). For example, in the robot 10 shown in Fig. 1, detailed determination based on geometric interference determination is performed for the fifth link 15 to the seventh link 17, which are links that cannot be determined. This makes it possible to prevent the operating range of the robot 10 from being restricted. In other words, the self-interference determination device 20 has a hybrid determination function that performs rough determination based on the self-interference method determination and detailed determination based on geometric interference determination.

[0019] FIG. 2 is a functional block diagram of the robot system 1. It should be noted that the "~ unit" of the self-interference determination device 20 is a functional module realized by a program executed by a processor, for example. The self-interference determination device 20 includes a self-interference equation definition unit 21, a self-interference equation determination unit 22, and a robot control unit 29. The self-interference equation definition unit 21 defines a self-interference equation for determining the possibility of self-interference of the robot 10, and the self-interference equation determination unit 22 determines the possibility of self-interference based on the defined self-interference equation. The robot control unit 29 controls the driving source 18 of the robot 10, and the driving 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 equation determination unit 22 with the current state of the link. The self-interference equation determination unit 22 determines the possibility of self-interference by substituting the provided current position or angle of the link into the self-interference equation.

[0020] 3 is a perspective view of the robot 10 showing an example of a self-interference equation definition method. For example, when defining the self-interference equations of the fifth link 15 to the seventh link 17, which are undeterminable links, the self-interference equation definition unit 21 first operates all links from the fourth link 14 on the base side of the robot 10 to the seventh link 17 on the tip side of the robot 10, and defines a cylinder 15-17 that includes the movable areas of all links from the fifth link 15 on the base side of the robot 10 to the seventh link 17 on the tip side of the robot 10. The self-interference equation definition unit 21 may acquire the link shapes of the fifth link 15 to the seventh link 17 from a link shape acquisition unit 25 described later.

[0021] Next, the self-interference equation definition unit 21 defines a self-interference equation for determining the possibility that the cylinder 15-17 including the movable areas of the fifth link 15 to the seventh link 17, which are undeterminable links, may interfere with, for example, the second link 12. Fig. 4 is a geometric diagram of the robot 10 showing an example of a method for defining the self-interference equation. It should be noted that for ease of understanding, Fig. 4 shows a simplified drawing of only the second link 12, the third and fourth links 13-14, and the cylinder 15-17.

[0022] Here, the base point of the second link 12 is P1, the center of rotation of the third link 13 is P2, the center of the cylinder 15-17 is P3, the nearest point of the cylinder 15-17 to the second link 12 is P4, and the intersection point of the perpendicular line drawn from the center P3 of the cylinder 15-17 to the center line of the second link 12 and the center line of the second link 12 is P5. Furthermore, the length of the line segment P2P3 is L1, the length of the line segment P3P4 is L2, the current angle of the third link 13 is θ1, and the current angle of the fifth link 15 (the angle formed by the line segments P2P3 and P3P4) is θ2.

[0023] At this time, the angle between the perpendicular line P3P5 and the line segment P3P4 is θ1+θ2-90°, so the magnitude of the cylinder 15-17 toward the second link 12 can be expressed as L2cos(θ1+θ2-90°). The magnitude of the second link 12 toward the cylinder 15-17 is R1. Meanwhile, the distance between the cylinder 15-17 and the second link 12 can be expressed as L1sinθ1. Therefore, when the distance L1sinθ1 between the cylinder 15-17 and the second link 12 is equal to or less than the sum of the magnitude L2cos(θ1+θ2-90°) of the cylinder 15-17 toward the second link 12 and the magnitude R1 of the second link 12 toward the cylinder 15-17, it is possible that the cylinder 15-17 (i.e., the fifth link 15 to the seventh link 17, which are the undeterminable links) may have interfered with the second link 12. In other words, the self-interference equation for determining the possibility that the undeterminable links (the fifth link 15 to the seventh link 17) self-interfere with the second link 12 can be expressed as follows.

[0024]

number

[0025] Here, L1, L2, and R1 are constants, so by substituting 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, it becomes possible to determine the possibility that the undeterminable link (the fifth link 15 to the seventh link 17) will self-interfere with the second link 12. The self-interference equation definition unit 21 defines self-interference equations using the same principle for other combinations of links that may self-interfere (for example, the fifth link 15 to the seventh link 17 and the first link 11).

[0026] 2 again, the robot control unit 29 provides the current state of the link (i.e., the current position or angle) to the self-interference type determination unit 22. The self-interference type determination unit 22 substitutes the current state of the link into the self-interference equation to determine whether or not there is a possibility of self-interference. For example, the self-interference type 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 type determination (rough determination).

[0027] The self-interference determination device 20 may further include an undeterminable link definition unit 23 and an undeterminable link determination unit 24. The undeterminable link definition unit 23 defines an undeterminable link that may self-interfere, and the undeterminable link determination unit 24 determines whether or not the undeterminable link actually has a possibility of self-interfering.

[0028] The undeterminable link definition unit 23 defines, for example, the fifth link 15 to the seventh link 17 as the undeterminable links. That is, the fifth link 15 to the seventh link 17 are undeterminable links that may self-interfere with the first link 11 or the second link 12, and the presence or absence of self-interference cannot be determined only from the positions or angles of these links. In other words, the fifth link 15 to the seventh link 17 are links whose centers of rotation do not exist on a virtual plane including the axis J1 of the first link 11.

[0029] The undeterminable link determination unit 24 determines whether or not the undeterminable links, for example, the fifth link 15 to the seventh link 17, actually have a possibility of self-interfering with the first link 11 or the second link 12. Specifically, the undeterminable link determination unit 24 determines whether or not the link determined by the self-interference determination unit 22 to have a possibility of self-interfering is a defined undeterminable link (the fifth link 15 to the seventh link 17).

[0030] If a link determined to have the possibility of self-interference by the self-interference type is not a defined undeterminable link but a determinable link, the link is one for which the presence or absence of self-interference can be accurately determined by the self-interference type, so the undeterminable link determiner 24 sends a command to stop the robot 10 to the robot control unit 29. The robot control unit 29 stops the driving source 18 of the robot 10 based on the stop command.

[0031] Alternatively, if a link determined to have the possibility of self-interference by the self-interference type is a defined undeterminable link, the presence or absence of self-interference cannot be accurately determined by the self-interference type, so the undeterminable link determiner 24 sends a geometric interference determination command to the geometric interference determiner 28. The self-interference determination device 20 further includes a link shape acquirer 25, a specified distance acquirer 26, a link shape corrector 27, and a geometric interference determiner 28.

[0032] The link shape acquisition unit 25 acquires the link shapes, the specified distance acquisition unit 26 acquires the specified distance between the link shapes at which the links are deemed to interfere with each other, the link shape correction unit 27 corrects the link shapes based on the specified distance, and the shape interference determination unit 28 makes a detailed determination of the presence or absence of self-interference based on whether the link shapes have approached each other to within the specified distance. The robot control unit 29 provides the shape interference determination unit 28 with the current states of the links (i.e., the current positions or angles, speed, etc.). The shape interference determination unit 28 calculates the current position and posture of the link shapes from the provided current positions or angles of the links.

[0033] The link shape acquisition unit 25 acquires link shapes of the first link 11, the second link 12, the fifth link 15, the sixth link 16, and the seventh link 17 that may self-interfere. Alternatively, the link shape acquisition unit 25 may acquire all of 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 acquires the link shapes from, for example, a memory or an external device.

[0034] The specified distance acquisition unit 26 acquires, for example, a specified distance of 50 mm between the link shapes at which the second link 12 and the fifth link 15 are deemed to have self-interfered with each other. As a result, when the second link 12 and the fifth link 15 approach each other to within the specified distance of 50 mm or less, it is deemed that self-interference has occurred, and the robot 10 can be stopped. Alternatively, the specified distance may be designated as a range, and in this case, the specified distance acquisition unit 26 acquires, for example, a range of 50 mm to 70 mm between the link shapes at which the second link 12 and the fifth link 15 are deemed to have self-interfered with each other. As a result, when the second link 12 and the fifth link 15 approach each other to within the specified range of 50 mm to 70 mm, it is deemed that self-interference has occurred, and the robot 10 can be stopped. The specified distance acquisition unit 26 acquires the specified distance from, for example, a memory or an external device.

[0035] For example, the link shape correction unit 27 enlarges the link shape by a specified distance. FIG. 5A is a perspective view of the robot 10 showing a link shape 15a enlarged by the specified distance. The link shape 15a is obtained by enlarging the actual link shape of the fifth link 15 by a specified distance of 50 mm. Alternatively, when the specified distance is specified as a range, the link shape correction unit 27 may simplify the link shape to fit within the specified range. FIG. 5B is a perspective view of the robot 10 showing a link shape 15b simplified to fit within the specified range. The link shape 15b is obtained by simplifying the actual link shape of the fifth link 15 to fit within a specified range of 50 mm to 70 mm. The link shape 15b is simplified to two cylinders 30, 31 and one sphere 32. The link shape may be simplified to one cylinder or one sphere, etc., as long as it fits within the specified range of 50 mm to 70 mm.

[0036] Similarly, the link shape correcting unit 27 also enlarges the other undeterminable links, such as the sixth link 16 and the seventh link 17, by the specified distance or simplifies them so that they fall within the specified range.

[0037] Referring again to FIG. 2, the shape interference determination unit 28 determines whether or not the enlarged link shape 15a of the fifth link 15 and the link shape of the second link 12 interfere (contact or intersect). For example, when using three-dimensional polygon data, it is advisable to determine whether or not the polygon faces contact or intersect with each other in a brute-force manner. For example, if one or more vertices of one polygon face are on the back side of the other polygon face and the remaining vertices are on the front side of the other polygon face, it can be determined that the link shapes interfere with each other. Such shape interference determination is superior in terms of calculation cost to a brute-force determination of whether or not the distance between the polygon faces is equal to or less than a specified distance.

[0038] Alternatively, the geometric interference determination unit 28 may determine whether or not there is interference (contact or intersect) between, for example, the simplified link shape 15b of the fifth link 15 and the link shape of the second link 12. For example, when three-dimensional polygon data is used, the simplified link shape 15b has an overwhelmingly smaller number of polygon faces than the enlarged link shape 15a, so that geometric interference determination based on the simplified link shape 15b is superior in terms of calculation cost to geometric interference determination based on the enlarged link shape 15a.

[0039] If it is determined that there is self-interference based on such geometric interference determination (detailed determination), the geometric interference determination unit 28 sends a command to stop the robot 10 to the robot control unit 29. The robot control unit 29 stops the driving source 18 of the robot 10 based on the stop command. Alternatively, if it is determined that there is no self-interference based on the geometric interference determination (detailed determination), the geometric interference determination unit 28 sends a determination command to the self-interference type determination unit 22 to return to the self-interference type determination (rough determination), or repeats the geometric interference determination (detailed determination).

[0040] The self-interference determination device 20 may further include a robot stop command unit (not shown) that calculates the current shortest distance between the link shapes and the current relative speed between the link shapes, determines whether the robot 10 can be stopped safely (softly) based on the shortest distance and the relative speed, and sends a safety stop command to the robot control unit 29 when it is determined that the robot 10 can be stopped safely. The robot stop command unit may send an emergency stop command to the robot control unit 29 when it is determined that the robot 10 cannot be stopped safely.

[0041] 6 is a flowchart showing an example of pre-processing of the self-interference determination device 20. This flowchart is executed, for example, by a processor of the self-interference determination device 20. In step S10, an undeterminable link is defined, which is a link for which the presence or absence of self-interference cannot be determined based only on the position or angle of the specific link. For example, the fifth link 15 to the seventh link 17, which are the undeterminable links, are input by a user operation via a graphical user interface (GUI).

[0042] In step S11, a self-interference equation for determining the possibility of self-interference between links is defined. For example, a conventional self-interference equation is defined for links for which the self-interference can be determined, and for links for which the self-interference cannot be determined, the self-interference equation is defined based on a shape that includes the movable areas of all links from the fifth link 15 on the base side of the robot 10 to the seventh link 17 on the tip side of the robot 10.

[0043] In step S12, the link shape is obtained. For example, the link shape is input from a memory or an external device. In step S13, a specified distance between the link shapes at which the links are considered to interfere with each other is obtained. For example, a specified distance of 50 mm is input by a user operation via the GUI. In step S14, the link shape is modified 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 fall within the specified range of 50 mm to 70 mm.

[0044] It should be noted that in the flowchart shown in FIG. 6, the order of steps S10-S11 and steps S12-S14, and the order of steps S12 and S13 may be reversed.

[0045] 7 is a flowchart showing 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 while the robot 10 is in operation. In step S20, the possibility of self-interference is determined based on the self-interference equation (i.e., a self-interference equation determination (rough determination) is performed). If it is determined that there is no possibility of self-interference based on the self-interference equation (NO in step S20), the self-interference equation determination (rough determination) in step S20 is repeated.

[0046] If it is determined that there is a possibility of self-interference using the self-interference type (YES in step S20), it is determined in step S21 whether or not the link determined to have the possibility of self-interference using the self-interference type is an undeterminable link. If the link determined to have the possibility of self-interference using the self-interference type is a determinable link (NO in step S21), self-interference has occurred, so the operation of the robot 10 is stopped in step S23. At this time, the current shortest distance between the link shapes and the current relative speed between the link shapes may be calculated, and the robot 10 may be brought to a safe stop based on the shortest distance and the relative speed.

[0047] If the link determined to have the possibility of self-interference by the self-interference method is an undeterminable link (YES in step S21), the presence or absence of self-interference is determined in step S22 based on whether the link shapes have approached each other to within a specified distance (i.e., a shape interference determination (detailed determination) is performed). For example, it is determined whether the link shape expanded by the specified distance interferes (contacts or intersects) with another link shape. Alternatively, if the specified distance is specified as a range, it is determined whether the simplified link shape interferes (contacts or intersects) with another link shape within the specified range.

[0048] 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 may be repeated. If it is determined that the link shapes interfere with each other (YES in step S22), self-interference exists, and the operation of the robot 10 is stopped in step S23. At this time, the current shortest distance between the link shapes and the current relative speed between the link shapes may be calculated, and the robot 10 may be brought to a safe stop based on the shortest distance and the relative speed.

[0049] The above-mentioned self-interference determination device 20 may be configured as a host computer device that sends various commands to the robot control device, rather than as a robot control device. Fig. 8 is a functional block diagram of a robot system 1 according to another embodiment. The robot system 1 includes one self-interference determination device 20, multiple robot control devices 40, and multiple robots 10. The current state of the link of each robot 10 (for example, the current position or angle, speed, etc.) is collected in the self-interference determination device 20 via each robot control device 40.

[0050] The self-interference determination device 20 performs self-interference type determination (rough determination) and shape interference determination (detailed determination) based on the current state (current position or angle, speed, etc.) of the links of each robot 10. If the self-interference determination device 20 determines that there is self-interference, it sends a stop command for each robot 10 to each robot controller 40. Each robot controller 40 stops the driving source 18 of each robot 10 based on the stop command.

[0051] It should be noted that the configurations of the robot system 1 and the self-interference determination device 20 described above are merely examples, and other configurations may be adopted. For example, the robot 10 may not be an industrial robot, but may be a robot of another form, such as a humanoid. Furthermore, the robot 10 may not be provided with a plurality of links in series, but may be a robot (e.g., a dual-arm robot) that has a plurality of links in parallel, and the geometric interference determination may be applied to the robot 10. Furthermore, the seventh link 17 of the robot 10 may not be a hand, but may be a tool portion of another form, such as a driver, a welding tool, or a sealing tool.

[0052] Furthermore, the self-interference determination device 20 may not have a processor that executes a program, but may have an integrated circuit that does not execute a program (for example, an FPGA (field-programmable gate array), an ASIC (application specific integrated circuit), etc.), and the integrated circuit may have the "unit" shown in FIG. 2. The flowcharts shown in FIGS. 6 and 7 may be executed by the integrated circuit, rather than by a processor. Furthermore, the self-interference determination device 20 may not have a hybrid determination function of self-interference determination (rough determination) and geometric interference determination (detailed determination), but may have only a geometric interference determination function.

[0053] Further, the link shape correction unit 27 may enlarge the link shape of the first link 11 or the second link 12 that may self-interfere with the fifth link 15, for example, instead of enlarging the link shape of the fifth link 15, which is an undeterminable link, by the specified distance. Alternatively, the link shape correction unit 27 may enlarge the link shapes of the fifth link 15 and the first link 11 or the second link 12, respectively, if they are within the specified distance. Similarly, when the specified distance is specified as a range, the link shape correction unit 27 may simplify the link shapes of the first link 11 or the second link 12 that may self-interfere with the fifth link 15, for example, instead of simplifying the link shape of the fifth link 15, which is an undeterminable link, so that it falls within the specified range, or may simplify the link shapes of the fifth link 15 and the first link 11 or the second link 12, respectively, if they are within the specified range.

[0054] In addition, when links are deemed to self-interfere based on the self-interference equation, even if one of these links is an indeterminable link where the presence or absence of self-interference cannot be determined based on the position or angle of that link alone, if self-interference can be determined based on the position or angle, etc. of the other link, the self-interference determination device 20 may be provided with an interference determination unit that does not perform geometric interference determination but simply determines self-interference of the indeterminable link based on the position, angle, etc. of the other link.

[0055] A program executed by the above-mentioned processor, other integrated circuits, etc., or a program executing the above-mentioned flowchart may be provided by being recorded on a computer-readable non-transitory recording medium, such as a CD-ROM, or may be provided by being distributed from a server device on a WAN (wide area network) or LAN (local area network) via wired or wireless communication.

[0056] Although various embodiments have been described herein, it should be appreciated that the present invention is not limited to the above-described embodiments, but may be modified in various ways within the scope of the appended claims. [Explanation of symbols]

[0057] 1. Robot System 10. Robot 11 First Link 12 Second Link 13 Third Link 14 Fourth Link 15 Fifth Link 15a Enlarged link shape 15b Simplified link shape 16 Sixth Link 17 Seventh Link 18 Power Source 13-14 3rd and 4th links 15-17 Cylinder 20 Self-interference detection device 21 Self-interference equation definition section 22 Self-interference judgment section 23 Undeterminable link definition 24 Undeterminable Link Determination Unit 25 Link shape acquisition section 26 Specified distance acquisition section 27 Link shape correction section 28 Geometric interference detection section 29 Robot control unit 30, 31 Cylinder 32 Sphere J1~J6 axis

Claims

1. A robot comprising at least one memory for storing information relating to a plurality of links of the robot; and at least one processor; The at least one processor defining an indeterminable link, the presence or absence of self-interference of which cannot be determined from the position or angle of one of the links, based on information about the links; determining whether the undeterminable link self-interferes; when it is determined that self-interference occurs, modifying the link shape of the undeterminable link based on a designated distance between link shapes that are deemed to have self-intersected; determining whether or not the self-interference of the undeterminable link exists based on the corrected link shape; A self-interference determination device that executes the process.

2. The self-interference determination device according to claim 1 , wherein modifying the link shape includes enlarging the link shape by the specified distance.

3. The self-interference determination device according to claim 1 or 2, wherein when the specified distance is specified as a range, modifying the link shape includes simplifying the link shape so that the link shape falls within the specified range.

4. The at least one processor The self-interference determination device according to claim 1 , further comprising a process for acquiring the designated distance.

5. The at least one processor The self-interference determination device according to claim 1 , further comprising a step of acquiring the link shape.

6. The at least one processor, The self-interference determination device according to claim 1 , further comprising: a process of calculating a current shortest distance between the link shapes and a current relative speed between the link shapes; and sending a safety stop command to bring the robot to a safe stop based on the shortest distance and the relative speed.

7. a self-interference equation definition unit that defines a self-interference equation for determining a possibility of self-interference of a robot having a plurality of links; a self-interference equation determination unit that determines the possibility of self-interference based on the self-interference equation defined by the self-interference equation definition unit; Equipped with The self-interference equation definition unit defines the self-interference equation for an undeterminable link for which the presence or absence of self-interference cannot be determined from the position or angle of a specific link regardless of the positions or angles of links other than the specific link, based on a shape that encompasses the movable areas of all links from the undeterminable link on the root side of the robot to the undeterminable link on the tip side of the robot.

8. an undeterminable link definition unit that defines the undeterminable link that may self-interfere; an undeterminable link determination unit that determines whether or not the undeterminable link actually has a possibility of self-interference; The self-interference determination device according to claim 7 , further comprising:

9. A self-interference determination device for determining self-interference of a robot having a plurality of links including a first link and a second link, an undeterminable link definition unit that defines an undeterminable link in which it is not possible to determine whether or not self-interference exists between either the first link or the second link based on a position or angle of the one link, based on information about the plurality of links; an undeterminable link determination unit that determines whether or not the undeterminable link defined by the undeterminable link definition unit actually has a possibility of self-interference; an interference determination unit that determines self-interference of the undeterminable link based on a result of the determination by the undeterminable link determination unit; A self-interference determination device comprising:

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