Robot control device

Abstract

A robot control device (20) is provided for controlling a robot, the robot control device (20) comprising: an area setting unit (201) for setting an operating area in which the robot can operate and a restricted area which the robot cannot enter; a position calculation unit (204) that calculates the position of the robot; an interference detection unit (205) that, based on the calculated position of the robot, detects the interference between the robot and the outer surface of the operating area or the restricted area; an operating state detection unit (206, 209) that detects the operating state of the robot from the time at which the interference is detected; and a stop unit (207) that stops the robot by means of a stop control according to the detected operating state.

Description

Technical area

[0001] The present invention relates to a robot control device. Related prior art

[0002] Various technologies have been proposed to ensure human safety in a work area where a robot system is located. For example, PTL 1 describes the following: "A robot arm performs low-speed arm speed control when a person approaches a first-stage area and stops the arm when the person approaches a second-stage area that is closer to the robot than the first-stage area" (paragraph 0016).

[0003] PTL 2 describes the following: “A robot system comprises: a robot arm 2; a human body identification device 4 that outputs human body identification information for distinguishing a human body from an object other than a human body in a predetermined monitoring area including a moving range of the robot arm 2;and a control device 3 that controls a movement of the robot arm 2, wherein the control device 3, when detecting the entry of a human body into the predetermined monitoring area by distinguishing a human body from an object other than a human body in the predetermined monitoring area based on the human body identification information outputted from the human body identification device 4, controls the robot arm 2 such that a movement of the robot arm 2 is slowed down or stopped." (Abstract).; Citation listPatent literature [PTL 1] Unexamined Japanese Patent Publication (Kokai) No. 2000-202790 A [PTL 2] Unexamined Japanese Patent Publication (Kokai) No. 2019-42871 A SummaryTechnical problem

[0004] To ensure the safety of a person in a work area where a robot system is arranged, the robot system can be configured to set a motion zone in which a robot is allowed to move or a boundary zone into which the robot is not allowed to enter as a computationally specified zone in a controller, and to cause the robot to perform an emergency stop when interference is detected between the robot and the outer surface of the motion zone or boundary zone. While such a safety function is important to ensure the safety of a person in a work area, another aspect of the safety function is that an emergency stop imposes a significant load on the robot mechanism. It is desirable to adaptively change the stop control when interference is detected between the robot and the outer surface of the motion zone or boundary zone. Solution to the problem

[0005] One embodiment of the present disclosure is a robot control device for controlling a robot, the robot control device comprising: a zone setting unit configured to set a movement zone in which the robot is allowed to move or a restriction zone into which the robot is not allowed to enter; a position calculation unit configured to calculate a position of the robot; an interference detection unit configured to detect, based on the calculated position of the robot, interference between the robot and an outer surface of the movement zone or the restriction zone; an operation state detection unit configured to detect an operation state of the robot when the interference is detected; and a stop unit configured to stop the robot according to a stop control based on the detected operation state. Advantageous effects of the invention

[0006] The configuration described above enables appropriate stop control based on the operating state of a robot when interference between the robot and the outer surface of a motion zone or a boundary zone is detected, and thus provides stop control that can reduce the load on the robot mechanism while ensuring the safety of an operator.

[0007] The objects, features and advantages of the present invention and other objects, features and advantages will become more apparent from the detailed description of typical embodiments of the present invention illustrated in the accompanying drawings. Brief description of the drawings

[0008] They show: Fig. 1 is a diagram showing the configuration of a robot system according to an embodiment; Fig. 2 is a diagram showing an example of setting a movement zone around a robot; Fig. 3 is a diagram showing examples of the hardware configuration of a robot control device and an external input device; Fig. 4 is a functional block diagram of a robot control device according to a first embodiment; Fig. 5A is a diagram showing an operation example of the stop control when a movement zone is specified in the first embodiment; Fig. 5B is a diagram showing an operation example of the stop control when a movement zone is specified in the first embodiment; Fig. 6A is a diagram showing an operation example of the stop control when a limit zone is specified in the first embodiment; Fig. 6B is a diagram showing an operation example of the stop control when a limit zone is specified in the first embodiment; Fig. 7A is a diagram showing an operation example in which a user coordinate system is set as reference coordinates in detecting a moving direction; Fig. 7B is a diagram showing an operation example in which the user coordinate system is set as reference coordinates in detecting a moving direction; Fig. 8 is a diagram showing a first example of a user interface screen for setting a specified zone and a stopping method in the first embodiment; Fig. 9 is a diagram showing a second example of a user interface for setting a specified zone and a stopping method in the first embodiment; Fig. 10 is a diagram showing an operation example when a component of the moving direction of the robot is determined; Fig. 11 is a diagram for describing a decision on a stopping method when there are a plurality of components with respect to the direction of movement of the robot; Fig. 12 is a diagram showing the interference between a robot model set on the robot and the outer surface of a motion zone; Fig. 13 is a functional block diagram of a robot control device according to a second embodiment; Fig. 14 is a diagram showing an example of the assignment of an identification number to a movement zone; Fig. 15 is a diagram showing an example of the assignment of an identification number to a movement zone; Fig. 16A is a diagram showing an operation example of the stop control when interference occurs between the outer surface of a moving zone and a robot in the second embodiment; Fig. 16B is a diagram showing an operation example of the stop control when interference occurs between the outer surface of the moving zone and the robot in the second embodiment; Fig. 17A is a diagram showing an operation example of the stop control when interference occurs between the outer surface of a boundary zone and the robot in the second embodiment; Fig. 17B is a diagram showing an operation example of the stop control when interference occurs between the outer surface of the restriction zone and the robot in the second embodiment; Fig. 18 is a diagram showing a user interface screen for setting a specified zone and a stopping method in a second embodiment; Fig. 19 is a functional block diagram of a robot control device according to a third embodiment; Fig. 20A is a diagram for describing the stop control in a zone-locked state; Fig. 20B is a diagram for describing the stop control in a zone-released state; Fig. 20C is a diagram describing the stop control in the zone-released state; and Fig. 21 is a diagram showing a user interface for setting a specified zone and a stopping method in the third embodiment. Description of implementation examples

[0009] Embodiments of the present disclosure will be described below with reference to the drawings. In the referenced drawings, similar components or functional parts are designated by similar reference numerals. To facilitate understanding, different scales may be used in the drawings. Furthermore, the configurations illustrated in the drawings are examples for implementing the present invention, but the present invention is not limited to the illustrated configurations.

[0010] Fig. 1 is a diagram showing a configuration of a robot system according to an embodiment. As shown in Fig. 1, the robot system 100 includes a robot 10, a robot controller 20 that controls the robot 10, and an external input device 40 connected to the robot controller 20. The external input device 40 is, for example, a teach pendant. An information processing device such as a tablet, a smartphone, or a personal computer (PC) can also be used as the external input device 40. For example, the robot 10 is assumed to be a six-axis articulated robot. Depending on the work target, various types of robots, such as a parallel-joint robot and a dual-arm robot, can be used as the robot 10. The joint axes of the robot 10 are referred to as the J1 axis, J2 axis, J3 axis, J4 axis, J5 axis, and J6 axis in this order from the base side.The J1 to J6 axes correspond to the rotation axes of the actuators provided for the respective axes. In . Fig. 1 the directions of rotation of the axes are specified by the arrows J1 to J6.

[0011] The robot 10 can perform the desired task using an end effector attached to the wrist. The end effector is an external device that can be replaced depending on its purpose, e.g., a hand, a welding gun, or a tool. Fig. Figure 1 shows an example where a hand is used as an end effector.

[0012] The robot control device 20 has a safety function that stops the robot 10 when the robot 10 leaves a movement zone or enters a restriction zone. The movement zone can be defined as a computational (i.e., virtual) zone that specifies an area within which the robot is permitted to move. The restriction zone can be defined as a computational (i.e., virtual) zone that specifies a zone into which the robot is not permitted to enter. The safety function includes a function for stopping the robot when the robot leaves the movement zone (i.e., when the robot interferes with the outer surface (interface) of the movement zone) and a function for stopping the robot when the robot 10 interferes with the restriction zone.

[0013] The security function is based on Fig. 2 described. Fig. 2 shows an example of a state in which a movement zone R1 is established around the robot 10. In the case where the movement zone R1 is specified, the robot 10 is stopped when interference is detected between the robot 10 and the outer surface of the movement zone R1. When the safety function performs an interference check, a cylindrical or spherical model (a robot model 101M) may be arranged around the robot 10 so as to enclose an arm, a joint, and a tool part, and the robot 10 may be stopped when interference is detected between the robot model 101M and the outer surface of the movement zone R1. Likewise, the robot may be stopped when interference is detected between the restriction zone and the robot 10 or the robot model 101M when a restriction zone is specified.

[0014] The robot control device 20 according to the present embodiment can stop the robot 10 according to the stop control based on the operating state of the robot 10 when interference is detected between the robot (or the robot model) and the outer surface of a movement zone or a restriction zone. Consequently, the robot control device 20 can prevent the occurrence of a situation in which the mechanism of the robot 10 is subjected to significant stress due to an emergency stop while maintaining human safety.

[0015] Fig. 3 shows examples of the hardware configuration of the robot control device 20 and the external input device 40. The robot control device 20 may be configured as a conventional computer, including a memory 22 (e.g., a read-only memory (ROM), a random access memory (RAM), or a non-volatile memory), various input / output interfaces (I / O interfaces) 23, an operation unit 24 having various operation switches, etc., connected to a processor 21 via a bus. The input / output interfaces 23 include a network interface, a serial interface, a sensor signal interface, and other interfaces for external devices.

[0016] The external input device 40 may be configured as a conventional computer, including a memory 42 (e.g., a read-only memory (ROM), a random access memory (RAM), or a non-volatile memory), an output unit 43, an operation unit 44 with a display device such as a keyboard (or a software keyboard), various input / output interfaces 45, etc., connected to a processor 41 via a bus. The input / output interfaces 45 include a network interface, a serial interface, and other interfaces of the device.

[0017] Three embodiments (a first embodiment to a third embodiment) relating to the robot control device 20 will be described below. For convenience, a robot control device according to the first embodiment will be referred to as robot control device 20, a robot control device according to the second embodiment will be referred to as robot control device 20A, and a robot control device according to the third embodiment will be referred to as robot control device 20B. First embodiment

[0018] Fig. 4 shows a functional block diagram of the robot control device 20 according to the first embodiment. As shown in Fig. 4, the robot control device 20 includes an operation control unit 201, a zone setting unit 202, a stopping method setting unit 203, a position calculation unit 204, an interference detection unit 205, a movement direction detection unit 206, and a stopping unit 207.

[0019] The operation control unit 201 controls the operation of the robot 10 according to a command from an operation program 208 or an external input device (a teach pendant) 40. In other words, the operation control unit 201 moves a predetermined control section of the robot 10 according to a command from the operation program 208 or the external input device 40 by performing servo control of a servo motor that drives each joint axis of the robot 10 based on the command and feedback information from a position sensor (such as an encoder) 11 arranged on each axis of the robot 10.

[0020] The zone setting unit 202 provides a function for setting a specified zone (a motion zone or a restriction zone). The function provided by the zone setting unit 202 may include a function for accepting an input for setting a specified zone from an external device or a user and storing the input in a storage unit. For example, the zone setting unit 202 may be configured to accept an input for setting a motion zone or a restriction zone via a UI screen to perform the setting of a motion zone or a restriction zone. In this case, the zone setting unit 202 may be configured to display the UI screen on a display screen of the display unit 43 of the external input device 40 and accept an input on the UI screen by an operation on an operation unit 44.In this case, the setting input may include information about the three-dimensional position and size of the specified zone. The zone setting unit 202 provides information about the specified zone to the interference detection unit 205.

[0021] The stopping method setting unit 203 provides a function for performing a setting related to stopping the robot when the robot 10 leaves the movement zone or interferes with the restriction zone. The function provided by the stopping method setting unit 203 may include a function for receiving an input for setting a stopping method from an external device or a user and storing the input in a storage unit. The setting input in this case includes, for example, the following items. (1) A reference coordinate system on the basis of which the position and direction of movement of the robot are detected. (2) Information in which a direction of movement of the robot at the time of detection of the interference is linked to a type of stop control.

[0022] The type of stop control is referred to below as a stop category. A stop category represents a type of stop control under which a robot is stopped and may include, for example, the following. (1) Stop Category 0: The robot's movement is stopped immediately by turning off the power to the robot's servo control. Since in Stop Category 0, the power to the servo control is turned off while the robot is moving, a trajectory in decelerating motion of the robot is not controlled. (2) Stop category 1: The robot servo drive is turned off after the robot movement has been decelerated and stopped.

[0023] Stop category 0 is used in situations with a high degree of urgency. The robot stops faster in stop category 0 than in stop category 1, but the load on the robot mechanism is greater in stop category 0 than in stop category 1. The stop method setting unit 203 may have the function of accepting an input for setting a stop method via a UI screen. In this case, the stop method setting unit 203 may be configured to display the UI screen on the display screen of the display unit 43 of the external input device 40 and accept an input to the UI screen through an operation on the operation unit 44.

[0024] The position calculation unit 204 calculates the position of the robot 10 through kinematic calculations based on position information from the position sensor 11 on each axis of the robot 10. The "position of the robot" as the target of the position calculation may include the position of any section of the robot, such as the position of a specified arm or joint on the robot, in addition to the position of a control section, such as a tool center point (TCP). If the robot 10 is equipped with a tool (an end effector), a position on the tool as the target of the position calculation may be regarded as "the position of the robot." Calculating a position may also include calculating a posture. The position calculation unit 204 provides the calculated position of the robot 10 to the interference detection unit 205.

[0025] The interference detection unit 205 detects whether the robot 10 interferes with the outer surface of the movement zone or the boundary zone based on the position of the robot 10 supplied from the position calculation unit 204 and the position information of the movement zone or the boundary zone set in the zone setting unit 202.

[0026] The movement direction detection unit 206 functions as an operating state detection unit that detects the operating state of the robot 10 when interference is detected by the interference detection unit 205. The movement direction detection unit 206 detects the movement direction of the robot 10 when the interference detection unit 205 detects interference. The movement direction of the robot can be determined based on position information of the robot 10 calculated by the position calculation unit 204 at a predetermined cycle. A coordinate system on the basis of which the movement direction of the robot 10 is determined is obtained from the zone setting unit 202 or the stopping method setting unit 203.

[0027] Based on the setting information set via the stop method setting unit 203, the stop unit 207 stops the robot according to a stop category corresponding to the moving direction of the robot 10 when interference is detected between the robot 10 and the outer surface of the moving zone or the boundary zone.

[0028] A specific operation example of the stop control when a movement zone is set as a specified zone will be explained with reference to Fig. 5A and Fig. 5B. In the Fig. 5A and Fig. In the situation shown in Figure 5B, a motion zone R101 is specified for the robot 10, and an operator OP is located at a position on the right side of the robot 10, as viewed from the front in the figure. In this situation, when the robot 10 leaves the motion zone R101, the robot controller stops the robot 10 according to stop category 0, placing more emphasis on human safety when the robot 10 moves toward the operator OP, while the robot controller stops the robot according to stop category 1 to consider the load on the robot 10 in other cases. In this example, it is assumed that a world coordinate system C1 fixed to the base of the robot 10 is used as the reference coordinate system for detecting the movement direction. Fig. 5A (and similarly in other similar diagrams), the direction of each coordinate axis in the world coordinate system C1 is specified in the upper right part of the diagram to facilitate description. In this example, the setting is made such that stop category 0 is used when the movement direction of robot 10 is a +Y direction, and stop category 1 is used for the remaining directions.

[0029] Fig. 5A shows a state where the robot 10 interferes with the outer surface of the motion zone R101. In this case, the movement direction of the robot 10 when the robot 10 interferes with the outer surface of the motion zone R101 is determined to be the +Y direction, and the robot 10 is stopped according to stop category 0. In this case, since the robot 10 leaves the motion zone R101 in a state where it moves toward the operator OP, the robot controller causes the robot 10 to perform an emergency stop according to stop category 0 so that the safety of the operator OP can be reliably ensured.

[0030] In the case of Fig. 5B, the direction of movement of the robot 10 when the robot 10 interferes with the outer surface of the movement zone R101 is determined as the -Y direction, and the robot 10 is stopped according to stop category 1. From the Fig. From the positional relationship between the robot 10 and the operator OP shown in Figure 5B, it can be seen that the safety of the operator OP is ensured when the robot 10 leaves the motion zone R101 by moving in the -Y direction. Accordingly, in this case, stopping the robot 10 according to stop category 1 can reduce the load on the robot 10 while ensuring the safety of the operator OP.

[0031] A specific operation example of the stop control when a limit zone is set as a specified zone will be explained with reference to Fig. 6A and Fig. 6B. In the Fig. 6A and Fig. In the situation shown in Figure 6B, the limit zones R102 and R103 are set to the robot 10, and an operator OP is located at a position on the right side of the robot 10, as viewed from the front in the figure. The limit zone R102 in Fig. 6A and the boundary zone R103 in Fig. 6B are arranged at different positions.

[0032] In this situation, when the robot 10 enters the boundary zone, the robot controller stops the robot 10 according to stop category 0, placing more emphasis on urgency when the robot 10 is moving in a direction approaching the operator OP, while the robot controller stops the robot according to stop category 1 to consider a load on the robot 10 in other cases. In this example, it is assumed that the world coordinate system C1 fixed to the base of the robot 10 is used as the reference coordinate system for detecting the movement direction. In this example, the setting is made such that stop category 0 is used when the movement direction of the robot 10 is the +Y direction, and stop category 1 is used for the other directions.

[0033] Fig. 6A shows a situation where the robot 10 enters the restriction zone R102 and interference is detected. In this case, the robot 10 moves in the +Y direction, and therefore, stop control is performed according to stop category 0. In this case, the robot 10 moves in a direction approaching the operator OP, and therefore, the operator's safety can be reliably ensured by the robot 10 executing an emergency stop according to stop category 0.

[0034] In the situation in Fig. 6B, the robot 10 is stopped according to stop category 1 because the robot 10 is moving in the -Y direction when the robot 10 interferes with the boundary zone R103. Fig. From the positional relationship between the robot 10 and the operator OP shown in Figure 6B, it is clear that the safety of the operator OP is ensured when the robot 10 enters the restriction zone R103 by moving in the -Y direction. Accordingly, in this case, stopping the robot according to stop category 1 can reduce the load on the robot while ensuring the safety of the operator OP.

[0035] Likewise, any user coordinate system set by the user can be used as a reference coordinate system, which is used as a reference in detecting the direction of movement in addition to the world coordinate system, as in the example described above. An operation example in which a coordinate system set by a user (hereinafter referred to as the user coordinate system) is used as a reference coordinate system for detecting the direction of movement will be described with reference to Fig. 7A and Fig. 7B. A user coordinate system is, for example, a coordinate system that is set to a workpiece in a motion zone or a workbench on which a workpiece is placed. Fig. 7A and Fig. 7B shows an operation example in which a motion zone R101 is set as the specified zone. In this situation, the operator OP is located on the left side of the robot 10 as viewed from the front in the figure. In this situation, when the robot 10 leaves the motion zone, the robot controller stops the robot 10 according to stop category 0, placing more emphasis on urgency when the robot 10 is moving in a direction approaching the operator OP, while the robot controller stops the robot according to stop category 1 to consider a load on the robot 10 in other cases. In this example, the setting is made such that stop category 0 is used when the movement direction of the robot 10 is the +Y direction in a user coordinate system U1, and stop category 1 is used for the remaining direction.

[0036] Fig. Fig. 7A shows a state in which the robot 10 interferes with the outer surface of the movement zone R101. In the case of Fig. 7A, the direction of movement of the robot 10 when the robot 10 interferes with the outer surface of the movement zone R101 is determined as the -Y direction, and the robot 10 is stopped according to stop category 1. From the Fig. From the positional relationship between the robot 10 and the operator OP shown in Figure 7A, it is clear that the safety of the operator OP is ensured when the robot 10 leaves the motion zone R101 by moving in the -Y direction. Accordingly, in this case, stopping the robot according to stop category 1 can reduce the load on the robot while ensuring the safety of the operator.

[0037] Fig. 7B shows a state where the robot 10 interferes with the outer surface of the motion zone R101. In this case, the movement direction of the robot 10 when the robot 10 interferes with the outer surface of the motion zone R101 is determined to be the +Y direction, and the robot 10 is stopped according to stop category 0. In this case, the robot 10 leaves the motion zone R101 by moving toward the operator OP, and therefore, the operator's safety can be reliably ensured by the robot 10 performing an emergency stop according to stop category 0.

[0038] Since a user coordinate system is a coordinate system that can be easily and intuitively grasped by a user, and by allowing a user to set a user coordinate system as a reference coordinate system in the safety function, it is possible for a user to easily and intuitively set a stopping method and recognize the moving direction of the robot.

[0039] Fig. 8 is a diagram showing a first example of a user interface (UI) screen for setting a specified zone and a stopping method. A UI screen 300 is provided by the function of the zone setting unit 202 and the stopping method setting unit 203. The UI screen 300 can be displayed on the display screen of the display unit 43 of the external input device 40, and input to the UI screen can be accepted by an operation of the operation unit 44.

[0040] The UI screen 300 includes a specification field 301 in which a movement zone or a boundary zone can be specified as a specified zone. Fig. Figure 8 shows an example in which a motion zone is specified as a specified zone. The position of the motion zone can be specified, for example, in a position specification field 304. For example, if a cuboid-shaped zone is set, diagonal positions are specified in the position specification field 304. A robot model for an interference check, as shown in Fig. 2, can be specified in a target model specification field 302.

[0041] The UI screen 310 also includes a specification field 305 for specifying a stopping method, a specification field 306 for specifying the movement direction of stopping category 0, and a specification field 303 for specifying a reference coordinate system when detecting the movement direction. In this example, stopping category 0 is used only for the direction specified in the specification field 306 for specifying the direction of stopping category 0, and the stopping category specified in the specification field 305 for a stopping method is used for the remaining directions. When setting in Fig. 8, the robot is stopped only in the +X direction according to stop category 0 and in the remaining directions according to stop category 1. The options that can be specified in the specification field 306 for a stop category include "none", "+X", "+Y", "+Z", "-X", "-Y", and "-Z".

[0042] Fig. Figure 9 shows a diagram illustrating a second example of UI screens for setting a specified zone and a stopping method. The UI screens are provided by the function of the zone setting unit 202 and the stopping method setting unit 203. The UI screens can be displayed on the display screen of the display unit 43 in the external input device 40, and an input to the UI screen can be accepted by an operation on the operation unit 44. Fig. 9, the UI screen 310 shown on the left mainly relates to the setting of a specified zone. Fig. 9 Screen 320 shown on the right is a setting screen for the detailed setting of a stopping procedure.

[0043] The UI screen 310 includes a zone specification field 311 in which a movement zone or a boundary zone can be specified as a specified zone. Fig. Figure 9 shows an example of a motion zone specified as a specified zone. The position of the motion zone can be specified, for example, in a position specification field 312. For example, if a cuboid-shaped zone is set, diagonal positions are specified in the position specification field 312. A robot model for an interference check, as shown in Fig. 2, can be specified in a target model specification field 313.

[0044] The UI screen 310 includes a stopping method specification field 314. When the stopping method specification field 314 is selected, the screen 320 for detailed setting of a stopping method can be opened. As shown in Fig. As shown in Figure 9, the UI screen 320 is configured such that different stopping methods can be set for the respective directions of movement. The UI screen 320 allows the setting (1) a detention category (a specification field 321), (2) the direction of movement of the robot when interference occurs (a specification field 322), and (3) a reference coordinate system used when detecting the direction of movement (a specification field 323) for each stopping method.

[0045] On the UI screen 320 of the user interface in Fig. 9 contains four stopping procedures with the following content. (1) Stopping procedure 1: Stopping category 0, direction of movement: +X direction, reference coordinate system: world coordinate system (2) Stopping method 2: Stopping category 0, movement direction: +Y direction, reference coordinate system: user coordinate system 1 (3) Stopping method 3: Non-stop setting, movement direction: +Z direction, reference coordinate system: user coordinate system 2 (4) Stopping procedure 4: Stopping category 1, movement direction: -X direction, reference coordinate system: user coordinate system 3

[0046] A component of the movement direction of the robot 10 when the robot 10 interferes with the outer surface of the movement zone or the boundary zone can be detected, and a stop category can be decided based on the detected component. When a plurality of components are detected as the movement direction, the robot controller 20 can decide a stop category using the following procedures. (A1) Detecting interference between the robot and the outer surface of the motion zone or the boundary zone. (A2) Detecting a variety of components in the direction of motion. (A3) Obtaining a stopping category for each movement component detected in the procedure (A2). (A4) Using a stop category with the highest priority among the stop categories obtained with procedure (A3).

[0047] A specific decision for a detention category based on the procedures described above using Fig. 10 and Fig. 11 described. Fig. Figure 10 shows a situation in which two components are detected as the direction of movement when the robot 10 leaves a movement zone R101. In the situation in Fig. 10, a +Y component and a -X component are obtained as components of the movement direction V of the robot. Fig. 11 shows a setting content for a stopping method used in this example (a UI screen 320A).

[0048] The components of the direction of movement that in this situation are Fig. 10 are the +Y component and the -X component, and therefore the stopping categories obtained in the procedure (A3) described above are the stopping category 0 and the stopping category 1, as shown in the fields with the reference numerals 325 and 326 in Fig. 11. Regarding the priority of a stop category, for example, a stop category that has greater significance for safety is assigned a higher priority. In this case, stop category 0 has a higher priority than stop category 1. Accordingly, in this case, stop category 0 is used in procedure (A4), and the robot 10 is stopped according to stop category 0. When the robot 10 leaves the movement zone R101 by moving towards an operator OP, as in Fig. 10, the robot 10 is caused to perform an emergency stop according to stop category 0 in order to ensure the safety of the operator OP.

[0049] In order to detect interference between the robot 10 and the outer surface of the movement zone or the boundary zone by calculation, the robot control device can be configured using the robot model 101M as shown in Fig. 12, determine whether there is an interference between a robot model 101M covering the robot 10 (cf. Fig. 2), and the outer surface of the movement zone or the boundary zone. Fig. Figure 12 shows a situation where a state of the robot model 101M covering the robot 10 is detected that interferes with the outer surface of the motion zone R101 (the robot model 101M deviates from the motion zone R101). By detecting the interference using the robot model 101M, the computational burden can be reduced. Second embodiment

[0050] The robot control device 20A according to the second embodiment will be described below. The robot control device 20A according to the second embodiment is configured to detect, among the surfaces constituting the outer surface of a movement zone or a restriction zone, a surface with which a robot 10 interferes, and to enable setting of a stop category based on the surface on which interference is detected.

[0051] Fig. 13 shows a functional block diagram of the robot control device 20A according to the second embodiment. In the functional block diagram in Fig. 13 is a functional block corresponding to a functional block in the robot control device 20 according to the first embodiment in Fig. 4, are provided with the same reference numeral. As in Fig. 13, the robot control device 20A includes an operation control unit 201, a zone setting unit 202, a stopping method setting unit 203A, a position calculation unit 204, an interference detection unit 205, an interference area detection unit 209, and a stopping unit 207A.

[0052] The stopping method setting unit 203A can provide a function for setting a stopping category for each surface of the outer surface of a movement zone or a boundary zone. The interference surface detection unit 209 functions as an operating state detection unit that detects the operating state of the robot 10 when interference is detected by the state detection unit 205. When interference is detected between the robot 10 and the outer surface of the movement zone or the boundary zone, the interference surface detection unit 209 determines which of the surfaces constituting the outer surface of the movement zone or the boundary zone the robot 10 is interfering with.

[0053] The stopping unit 207A stops the robot 10 according to a stopping category set on an area detected by the interference area detecting unit 209.

[0054] If a stopping category is specified for each area of ​​a specified zone, identification information can be assigned to each side of the specified zone, as shown in Fig. 14 and Fig. 15 shown. Fig. Figure 14 shows an example of the assignment of identification numbers 1 to 6 for the front, right side, back, left side, bottom / bottom surface, and top / top surface, respectively, when a cuboid-shaped movement zone R1 is set. The identification numbers 1 to 6 are shown in Fig. 14 specified by circled numbers.

[0055] Fig. Figure 15 shows a state in which an octagonal prism-shaped movement zone R2 has been set up around the robot, with the eight sides assigned identification numbers 1 to 8 and the top / surface and the bottom / bottom surface assigned identification numbers 9 and 10, respectively. The identification numbers 1 to 10 are shown in Fig. 15 is specified by circled numbers. The interference surface detection unit 209 and the stopping unit 207A can identify the surfaces of the outer surface of the specified zone using the identification numbers. By assigning identification information to each surface of the outer surface constituting a specific zone to identify each surface, a stopping category can be efficiently defined for each surface, even if the specific zone is specified as a polyhedron.

[0056] Fig. Figure 16A shows a state in which a cuboid-shaped motion zone R101 is set. If the lower side in the figure is assumed to be the front side, the identification numbers 1 to 4 are assigned to the front, right side, back, and left side of the motion zone R101, respectively. The identification numbers are shown in Fig. 16A (and other similar diagrams) are specified by circled numbers. This example assumes that stopping category 0 is set on the area with identification number 2 (the right side) and stopping category 1 on the remaining areas.

[0057] Fig. 16A shows a situation where the robot 10 exits the movement zone R101 in a state where it interferes with an area with identification number 2 (the right side). In this case, the robot 10 is stopped according to the stop category 0 assigned to the area with identification number 2 (the right side). In this case, the robot 10 exits the movement zone R101 by moving toward an operator OP, so the safety of the operator OP is reliably ensured.

[0058] Fig. 16B shows a situation where the robot 10 exits the movement zone R101 in a state where it interferes with an area with identification number 4 (the left side). In this case, the robot 10 is stopped according to stop category 1 assigned to the area with identification number 4 (the left side). Since the robot 10 exits the movement zone R101 in this case by moving in a direction away from the operator OP, the robot control device operates to prevent stress on the robot 10 while ensuring the safety of the operator OP.

[0059] Fig. 17A and Fig. 17B show an operation example in which an identification number is assigned to each surface constituting the outer surface of a boundary zone. The figures show a state in which identification numbers 1 to 4 are assigned to the front, right, rear, and left sides of each of the boundary zones R102 and R103, respectively, with the lower side in the diagram assumed to be the front. In this case, it is assumed that stopping category 0 is set on a surface with identification number 4 (the left side) and stopping category 1 is set on the remaining surfaces.

[0060] Fig. Figure 17A shows a situation in which the robot 10 enters the boundary zone R102 by interfering with the area of ​​the boundary zone R102 with the identification number 4 (the left side). In this case, the robot 10 is stopped according to the stop category 0 set on the area with the identification number 4 (the left side). In the situation in Fig. 17A, an operator OP is located on the right side of the boundary zone R102. Accordingly, in a situation where the robot 10 enters the boundary zone R102 in such a way that it approaches the operator OP, as shown in Fig. 17A, stopped according to stopping category 0 in order to reliably ensure the safety of the operator OP.

[0061] Fig. Figure 17B shows a situation in which the robot 10 enters the boundary zone R103 by interfering with a surface of the boundary zone R103 with the identification number 2 (the right side). In this case, the robot 10 is stopped according to the stop category 1 set on the surface with the identification number 2 (the right side). The operator OP is in this situation in Fig. 17B on the right side of the boundary zone R103. Accordingly, in a situation where the robot 10 enters the boundary zone R103 and moves away from the operator OP, as shown in Fig. 17B, ​​is stopped according to stop category 1 to prevent stress on the robot 10 while ensuring the safety of the operator OP.

[0062] Fig. 18 is a diagram showing an example of user interface (UI) screens for setting a specified zone and a stopping method according to the second embodiment. The UI screens are provided by the function of the zone setting unit 202 and the stopping method setting unit 203A. The UI screens can be displayed on a display screen of a display unit 43 in an external input device 40, and an input to the UI screen can be accepted by an operation on an operation unit 44. Fig. 18, the UI screen 410 shown on the left mainly relates to the setting of a specified zone. Fig. 18 Screen 420 shown on the right is a setting screen for detailed setting of a stopping procedure.

[0063] The UI screen 410 includes specification fields corresponding to the specification fields 311 to 314 on the Fig. 9. The UI screen 410 includes a specification field 411 for a stopping method. For example, when an operation to select the specification field 411 is performed, the UI screen 420 for setting the details of a stopping method can be opened. As shown in Fig. As shown in Figure 18, the UI screen 420 is configured such that a variety of stopping methods can be set for the respective surfaces with which the robot interferes. Thus, the UI screen 420 can (1) a stop category (a specification field 421) and (2) an area with which the robot interferes (a specification field 422) can be set for each method.

[0064] By setting a stopping procedure for each area, the configuration of the stopping procedure content can be simplified. An operator only needs to assign each area of ​​a specified zone to a stopping category and can therefore configure the stopping procedure in a simple and intuitive manner.

[0065] On the UI screen 420 in Fig. 18 contains four stopping procedures with the following content. Procedure 1: specified area 1 (identification number 1), stopping category 0 Procedure 2: specified area 2 (identification number 2), stopping category 0 Procedure 3: specified area 3 (identification number 3), non-stop Procedure 4: specified area 4 (identification number 4), stopping category 1 Third embodiment

[0066] The robot control device 20B according to the third embodiment will be described below. The robot control device 20B according to the third embodiment is configured to enable setting of whether a restriction zone is enabled or disabled, to set a restriction zone as enabled when an operator enters the restriction zone, and to stop a robot 10 according to a stop category based on the robot's movement direction in the restriction zone when the operator enters the restriction zone.

[0067] The above-described function of the robot control device 20B can be achieved by disposing a sensor for detecting the entry of a person into a restriction zone, inputting a signal from the sensor to the robot control device 20B, and controlling to release the restriction zone when the entry of a person into the restriction zone is detected. Various sensors, such as a light curtain, a safety mat, and an area sensor, can be used as the sensor for detecting the entry of a person into the restriction zone. In addition to the signal from a sensor, an input from an I / O device, such as a sequencer, via the input-output interface 45 can also be used as the signal for detecting the entry of a person into the restriction zone.

[0068] Fig. 19 shows a functional block diagram of the robot control device 20B according to the third embodiment. In Fig. 19, a functional block similar to a functional block in the robot control device 20 according to the first embodiment is provided with the same reference numeral. As in Fig. As shown in Figure 19, the robot control device 20B includes a zone setting unit 202B, a stopping method setting unit 203, a position calculation unit 204, an interference detection unit 205B, a movement direction detection unit 206, and a stopping unit 207 as functional blocks related to the safety function. A detection signal from a sensor 80 that detects a person entering a restriction zone is input to the interference detection unit 205B.

[0069] In addition to functioning as the zone setting unit 202 according to the first embodiment, the zone setting unit 202B is configured to provide a function for enabling or disabling a specified zone. When the entry of a person into the restriction zone is detected by the sensor 80, the interference detection unit 205B enables the restriction zone. If interference between the robot 10 and the restriction zone is detected in this situation, it reports this to the movement direction detection unit 206. On the other hand, if the entry of a person into the restriction zone is not detected by the sensor 80, the interference detection unit 205B considers the restriction zone to be blocked.

[0070] The movement direction detection unit 206 functions as an operating state detection unit that detects the operating state of the robot 10 when interference is detected by the interference detection unit 205B. The movement direction detection unit 206 detects the movement direction of the robot 10 when a person enters the boundary zone and interference is detected between the robot 10 and the boundary zone. The stop unit 207 stops the robot 10 according to the stop control based on the movement direction of the robot 10 when a person enters the boundary zone in a situation where interference is detected between the robot 10 and the boundary zone.

[0071] A specific operational example is given with reference to Fig. 20A to Fig. 20C described. Fig. 20A to Fig. 20C shows a situation where a boundary zone R110 is set at the front of the robot 10, and an operator OP can enter the boundary zone R110. In this example, assume that with a world coordinate system C1 set at the base of the robot 10 as a reference, a stop category 0 is set to a +X direction as the movement direction and a stop category 1 is set to a -X direction as the movement direction.

[0072] In a condition according to Fig. 20A, the operator OP has not entered the boundary zone R110, so the boundary zone R110 is locked. In this case, the interference detection unit 205B assumes that the boundary zone R110 is locked and does not check for detection of interference between the robot 10 and the boundary zone R110. In this example, although no stop control is executed when the robot 10 interferes with the boundary zone R110, it is possible to avoid a load on the robot 10 due to the stop control while ensuring the safety of the operator OP.

[0073] Fig. 20B shows a situation where the operator OP has entered the restriction zone R110. In this case, the operator OP's entry into the restriction zone R110 is detected by the sensor 80, and the restriction zone R110 is released. In this situation, the robot 10 has entered the restriction zone R110 when the restriction zone R110 is released, and the movement direction of the robot 10 is in the +X direction; therefore, the robot 10 is caused to perform an emergency stop according to stop category 0. Consequently, the safety of the operator OP is reliably ensured.

[0074] Fig. 20C shows a situation where the operator OP has entered the restriction zone R110. In this case, the entry of the operator OP into the restriction zone R110 is detected by the sensor 80, and the restriction zone R110 is released. In this situation, the robot 10 has entered the restriction zone R110 when the restriction zone R110 is released, and the moving direction of the robot 10 is the -X direction; therefore, the robot 10 is stopped according to stop category 1. In this case, since the robot 10 moves in a direction away from the operator OP, the load on the robot 10 is reduced in a state where the safety of the operator OP is maintained.

[0075] Fig. 21 shows an example of a UI screen used in the setting according to the third embodiment. A UI screen 300A is provided by the function of the zone setting unit 202B and the stopping method setting unit 203. The UI screen 300A can be displayed on a display screen of a display unit 43 of an external input device 40, and an input to the UI screen 300A can be accepted by an operation on an operation unit 44. The UI screen 300A used in the present embodiment can be provided in such a way that the UI screen 300 according to the first embodiment described with reference to Fig. 8, a specification field 309 is added for specifying a signal for enabling / disabling a specified zone. For example, in the UI screen 300A, a signal from a safety mat is set as a signal for locking a restriction zone. Based on a setting content in a specification field 315, the interference detection unit 205B can identify which state of a signal from the sensor 80 represents an instruction to lock the restriction zone. In the UI screen 300A, a direction of stopping category 0 can be specified in a specification field 305A to set a stopping method.

[0076] While the present embodiment includes an operation example of setting a restriction zone as a specified zone and performing stop control during the locking or unlocking of the restriction zone based on a signal from the sensor 80, a configuration may also be employed in which a movement zone is set as a specified zone, the entry of a person into the movement zone is detected by the sensor 80, and stop control is performed during the locking or unlocking of the movement zone based on a signal from the sensor 80. Also, in this case, similar to the above-described embodiment, stop control can be performed that reduces the load on the robot while ensuring the safety of the operator.

[0077] In the present embodiment, an operation example has been described in which the robot control device enables setting of the zone enabling or disabling in the case where the robot is stopped according to a stopping category corresponding to the moving direction of the robot 10 when interference with the outer surface of a moving zone or a restriction zone is detected.Likewise, in the second embodiment, in which an area of ​​the outer surface of a movement zone or a restriction zone with which the robot 10 interferes is detected, when interference is detected between the robot 10 and the outer surface of the movement zone or the restriction zone, and the robot 10 is stopped according to a stop category set on the detected area, the robot control device can enable setting of the zone's release or lock, so that stop control can be performed while a movement zone is locked or released based on a signal from the sensor 80. Also, in this case, similar to the above-described embodiment, the stop control can reduce the load on the robot while ensuring operator safety.

[0078] As described above, according to each embodiment, when interference is detected between a robot and the outer surface of a movement zone or a restriction zone, appropriate stop control can be applied based on the operating state of the robot, so that stop control that reduces the load on the robot mechanism while ensuring the safety of an operator can be achieved.

[0079] Although the present invention has been described above with reference to the typical embodiments, it will be apparent to those skilled in the art that changes and various other modifications, omissions and additions can be made to the embodiments described above without departing from the scope of the present invention.

[0080] The arrangement of the functions shown in the functional block diagrams of the robot control devices according to the above-described embodiments ( Fig. 4, Fig. 13 and Fig. 19) are examples, and various modified examples may be configured with respect to the arrangement of the functional blocks. For example, there may be a configuration example in which at least part of the functional blocks related to the safety function and arranged in the robot control direction (such as the zone setting unit and the stopping method setting unit) are arranged in a teach pendant as an external input device. In this case, an overall function in which the function of the teach pendant as an external input device is combined with the function of the robot control device can be defined as a robot control device.

[0081] It goes without saying that with regard to the detection of interference between a robot and the outer surface of a motion zone or a boundary zone, “interference is detected between the robot and the outer surface of the motion zone or the boundary zone” means that interference is detected between any portion (which may include any portion from the base of the robot to a tool part) constituting the robot (or a robot model covering the robot) and the outer surface of the motion zone or the boundary zone.Furthermore, with respect to the detection of a moving direction or an interference surface, when interference is detected between a robot and the outer surface of a moving zone or a boundary zone, it goes without saying that “the moving direction of the robot and an interference surface that interferes with the robot are detected” when interference is detected between any portion (which may include any portion from the base of the robot to a tool part) constituting the robot (or a robot model covering the robot) and the outer surface of the moving zone or the boundary zone.

[0082] The functional blocks of the Fig. 4, Fig. 13 and Fig.19 may be provided by the execution of various types of software stored in a memory device, by the processor in the robot control device, or by a primarily hardware-based configuration such as an application-specific integrated circuit (ASIC).

[0083] A program that executes various types of processing such as methods for deciding a stopping category in the above-described embodiments can be recorded on various computer-readable recording media (e.g., semiconductor memories such as a ROM, an EEPROM, and a flash memory; a magnetic recording medium; and optical disks such as a CD-ROM and a DVD-ROM). List of reference symbols 10 robots 11 Position sensor 20, 20A, 20B Robot control device 21 processor 22 storage 23 Input-output interface 24 Control unit 40 External input device 41 processor 42 storage 43 Display unit 44 Control unit 45 Input-output interface 100 robot system 101M robot model 201 Operating control unit 202, 202B zone setting unit 203, 203A, 203B stopping method setting unit 204 Position calculation unit 205, 205B Interference detection unit 206 Movement direction detection unit 207, 207A stopping unit 208 Operating program 209 Interference area detection unit 310A, 320, 320A, 410, 420 UI screen QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2000-202790 A

[0003] JP 2019-42871 A

[0003]

Claims

[1] A robot control device for controlling a robot, the robot control device comprising: a zone setting unit configured to set a movement zone in which the robot is allowed to move or a restriction zone into which the robot is not allowed to enter; a position calculation unit configured to calculate a position of the robot; an interference detection unit configured to detect interference between the robot and an outer surface of the movement zone or the boundary zone based on the calculated position of the robot; an operating state detection unit configured to detect an operating state of the robot when the interference is detected; and a stopping unit configured to stop the robot according to a stopping control based on the detected operating state. [2] A robot control device according to claim 1, further comprising a stopping method setting unit configured to set the stopping control based on the operating state of the robot, wherein the stopping unit stops the robot according to the stopping control based on the operating state and set by the stopping method setting unit. [3] Robot control device according to claim 2, wherein the operating state detection unit comprises a movement direction detection unit configured to detect a movement direction of the robot when the interference is detected, and the stopping unit stops the robot according to the stopping control based on the moving direction of the robot when the interference is detected. [4] The robot control device according to claim 3, wherein the stopping method setting unit is configured to be capable of setting a different stopping control for each moving direction of the robot. [5] The robot control device according to claim 3 or 4, wherein the stopping method setting unit is configured to be capable of setting a coordinate system as a reference when a moving direction of the robot is detected by the moving direction detecting unit. [6] Robot control device according to claim 2, wherein the operating state detection unit comprises an interference surface detection unit configured to detect, from a plurality of surfaces constituting an outer surface of the movement zone or an outer surface of the boundary zone, an area with which the robot interferes when the interference is detected, and the stopping unit stops the robot according to the stopping control based on the surface interfering with the robot from the plurality of surfaces when the interference is detected. [7] The robot control device according to claim 6, wherein the stop method setting unit is configured to be capable of setting a different stop control for each surface constituting the outer surface of the moving zone or the outer surface of the restriction zone. [8] Robot control device according to claim 3, wherein the zone setting unit is configured to be able to specify a signal for switching between enabling and disabling the motion zone or the restriction zone, the interference detection unit is configured to detect the interference when, based on the signal, the movement zone or the restriction zone is released, and the stopping unit stops the robot according to the stopping control based on the moving direction of the robot when the interference is detected in a case where the moving zone or the limit zone is released due to the signal. [9] The robot control device according to claim 8, wherein the zone setting unit is configured to be capable of specifying a detection signal from a sensor for detecting the entry of a person into the movement zone or the restriction zone as the signal for switching between the enabling and disabling of the movement zone or the restriction zone. [10] The robot control device according to any one of claims 2 to 9, wherein the stop method setting unit is configured to accept a setting of the stop control based on the operation state of the robot via a user interface screen. [11] The robot control device according to any one of claims 1 to 10, wherein the zone setting unit is configured to accept a setting regarding the movement zone or the restriction zone via a user interface screen.

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