Robot control device

Abstract

Provided is a robot control device (20) which controls a robot, the robot control device (20) comprising: an area setting unit (201) for setting an operation area in which the robot can operate or a restricted area that the robot cannot enter; a position calculation unit (204) that calculates the position of the robot; an interference detection unit (205) that detects the interference between the robot and the outer surface of the operation area, or the restricted area, on the basis of the calculated position of the robot; an operation state detection unit (206, 209) that detects the operation state of the robot from when the interference is detected; and a stop unit (207) that stops the robot through stop control according to the detected operation state.

Description

[Technical Field]

[0001] The present invention relates to a robot control device. [Background technology]

[0002] Various technologies have been proposed to ensure safety in the workspace where the robot system is located. For example, Patent Document 1 states that "in an arm-type robot, when a person approaches within a first stage range, the speed of the arm is controlled to slow down, and when the person approaches within a second stage range, which is closer than that, the arm is stopped" (paragraph 0016).

[0003] Patent Document 2 states that "the robot comprises a robot arm 2, a human body identifier 4 that outputs human body identification information for distinguishing between human bodies and non-human objects in a predetermined monitoring area that includes the operating range of the robot arm 2, and a controller 3 that controls the operation of the robot arm 2, wherein the controller 3 is configured to distinguish between human bodies and non-human objects in the predetermined monitoring area based on the human body identification information output by the human body identifier 4, and to control the robot arm 2 to slow down or stop the operation of the robot arm 2 when it detects that a human body has entered the predetermined monitoring area" (abstract). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-202790 [Patent Document 2] Japanese Patent Application Publication No. 2019-42871 Summary of the Invention [Problem to be solved by the invention]

[0005] In a robot system, a range of motion within which the robot can operate or a restricted area within which the robot cannot enter is set as a designated area calculated within the control device, and the robot is brought to an emergency stop when interference between the robot and the outer surface of the range of motion or the restricted area is detected. While such safety functions are important from the perspective of ensuring the safety of people within the workspace, emergency stops can impose a load on the robot's mechanical components. It is desirable to be able to adaptively change the stop control applied when interference between the outer surface of the range of motion of the robot or the restricted area is detected. [Means for solving the problem]

[0006] One aspect of the present disclosure is a robot control device that controls a robot, comprising: an area setting unit that sets an operating area in which the robot can operate or a restricted area in which the robot cannot enter; a position calculation unit that calculates the position of the robot; an interference detection unit that detects interference between the robot and the outer surface of the operating area or the restricted area based on the calculated position of the robot; an operation state detection unit that detects the operating state of the robot when the interference is detected; and a stop unit that stops the robot by stop control according to the detected operating state. [Effects of the Invention]

[0007] According to the above configuration, when interference with the outer surface of the robot's operating area or a restricted area is detected, appropriate stop control can be applied depending on the operating state of the robot, thereby realizing stop control that reduces the load on the robot mechanism while ensuring the safety of the operator.

[0008] These and other objects, features and advantages of the present invention will become more apparent from the detailed description of exemplary embodiments of the invention illustrated in the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a diagram illustrating a device configuration of a robot system according to an embodiment. [Figure 2] FIG. 10 is a diagram showing an example in which an operating area is set around a robot. [Figure 3] FIG. 2 is a diagram illustrating an example of the hardware configuration of a robot control device and an external input device. [Figure 4] 1 is a functional block diagram of a robot control device according to a first embodiment. FIG. [Figure 5A] FIG. 4 is a diagram illustrating an example of stop control operation when a motion area is designated in the first embodiment. [Figure 5B] FIG. 4 is a diagram illustrating an example of stop control operation when a motion area is designated in the first embodiment. [Figure 6A] 5A to 5C are diagrams illustrating an example of the operation of stop control when a restricted area is designated in the first embodiment. [Figure 6B] 5A to 5C are diagrams illustrating an example of the operation of stop control when a restricted area is designated in the first embodiment. [Figure 7A] 10A and 10B are diagrams illustrating an example of operation when a user coordinate system is set as a reference coordinate for detecting a direction of movement. [Figure 7B] 10A and 10B are diagrams illustrating an example of operation when a user coordinate system is set as a reference coordinate for detecting a direction of movement. [Figure 8] FIG. 10 is a diagram showing a first example of a user interface screen for setting a designated area and a stopping method in the first embodiment. [Figure 9] FIG. 10 is a diagram showing a second example of a user interface screen for setting a designated area and a stopping method in the first embodiment. [Figure 10] 10A and 10B are diagrams for explaining an example of operation when determining a component of the robot's movement direction. [Figure 11] FIG. 10 is a diagram for explaining how to determine a stopping method when the robot's motion direction has multiple components. [Figure 12] FIG. 10 is a diagram showing interference between a robot model set in a robot and the outer surface of the operating area. [Figure 13] FIG. 10 is a functional block diagram of a robot control device according to a second embodiment. [Figure 14] FIG. 10 is a diagram illustrating an example of assigning identification numbers to motion areas. [Figure 15] FIG. 10 is a diagram illustrating an example of assigning identification numbers to motion areas. [Figure 16A] 10A and 10B are diagrams illustrating an example of the operation of stop control when interference occurs between the outer surface of the motion area and the robot in the second embodiment. [Figure 16B] 10A and 10B are diagrams illustrating an example of the operation of stop control when interference occurs between the outer surface of the motion area and the robot in the second embodiment. [Figure 17A] 10A and 10B are diagrams illustrating an example of the operation of stop control when interference occurs between the outer surface of a restricted area and the robot in the second embodiment. [Figure 17B] 10A and 10B are diagrams illustrating an example of the operation of stop control when interference occurs between the outer surface of a restricted area and the robot in the second embodiment. [Figure 18] FIG. 10 is a diagram showing a user interface screen for setting a designated area and a stopping method in the second embodiment. [Figure 19] FIG. 10 is a functional block diagram of a robot control device according to a third embodiment. [Figure 20A] FIG. 10 is a diagram for explaining stop control in an area invalid state. [Figure 20B] FIG. 10 is a diagram for explaining stop control in a valid region state. [Figure 20C] FIG. 10 is a diagram for explaining stop control in a valid region state. [Figure 21] FIG. 11 is a diagram showing a user interface screen for setting a designated area and a stopping method in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, like components or functional parts are designated by like reference numerals. The scales of these drawings have been changed appropriately to facilitate understanding. Furthermore, the embodiment shown in the drawings is one example for implementing the present invention, and the present invention is not limited to the illustrated embodiment.

[0011] FIG. 1 is a diagram illustrating the configuration of a robot system according to an embodiment. As shown in FIG. 1, the robot system 100 includes a robot 10, a robot control device 20 that controls the robot 10, and an external input device 40 connected to the robot control device 20. The external input device 40 is, for example, a teaching pendant. Note that the external input device 40 may also be an information processing device such as a tablet terminal, a smartphone, or a personal computer (PC). The robot 10 is, for example, a six-axis articulated robot. Note that various types of robots, such as parallel-link robots and dual-arm robots, may also be used depending on the work target. 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, starting from the base. The J1 axis to the J6 axis correspond to rotation axes controlled by actuators provided for the respective axes. In FIG. 1, the rotation directions of the axes are indicated by arrows J1 to J6.

[0012] The robot 10 can perform a desired task using an end effector attached to its wrist. The end effector is an external device that can be replaced depending on the application, such as a hand, a welding gun, or a tool. Figure 1 shows an example in which a hand is used as the end effector.

[0013] The robot control device 20 has a safety function that stops the robot 10 when it deviates from the operating area or when it enters a restricted area. The operating area may be defined as a calculated (i.e., virtual) area that specifies an area in which the robot can operate. The restricted area may be defined as a calculated (i.e., virtual) area that specifies an area in which the robot cannot enter. The safety function includes a function that stops the robot when it deviates from the operating area (i.e., when it interferes with the outer surface (boundary surface) of the operating area) and a function that stops the robot when it interferes with the restricted area.

[0014] This safety function will be described with reference to Figure 2. Figure 2 shows an example in which an operating region R1 is set around the robot 10. When the operating region R1 is set, the robot 10 is stopped if interference between the robot 10 and the outer surface of the operating region R1 is detected. When performing an interference check using the safety function, a cylindrical or spherical model (robot model 101M) may be set around the robot 10 to surround the arms, joints, and tool unit, and the robot 10 may be stopped if interference between this robot model 101M and the outer surface of the operating region R1 is detected. Similarly, when a restricted region is set, the robot can be stopped if interference with the robot 10 or robot model 101M is detected.

[0015] When interference between the robot (or robot model) and the outer surface of the motion area or the restricted area is detected, the robot control device 20 according to this embodiment can stop the robot 10 by performing stop control according to the motion state of the robot 10. This allows the robot control device 20 to reduce the occurrence of situations in which a load is placed on the mechanism of the robot 10 due to an emergency stop, while maintaining safety.

[0016] 3 shows an example of the hardware configuration of the robot control device 20 and the external input device 40. The robot control device 20 may have a configuration as a general computer, in which a memory 22 (ROM, RAM, non-volatile memory, etc.), various input / output interfaces 23, an operation unit 24 including various operation switches, etc. are connected to a processor 21 via a bus. The input / output interface 23 includes a network interface, a serial interface, a sensor signal interface, and other external device interfaces.

[0017] The external input device 40 may have a configuration as a general computer, in which a memory 42 (ROM, RAM, non-volatile memory, etc.), a display unit 43, an operation unit 44 consisting of input devices such as a keyboard (or software keys), and various input / output interfaces 45 are connected via a bus to a processor 41. The input / output interface 45 includes a network interface, a serial interface, and other external device interfaces.

[0018] Below, we will explain three embodiments (first to third embodiments) of the robot control device 20. For ease of explanation, the robot control device according to the first embodiment will be referred to as the robot control device 20, the robot control device according to the second embodiment as the robot control device 20A, and the robot control device according to the third embodiment as the robot control device 20B.

[0019] First embodiment 4 is 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 a movement control unit 201, an area 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.

[0020] The operation control unit 201 controls the robot 10 in accordance with commands from the operation program 208 or the external input device (teaching console) 40. That is, the operation control unit 201 executes servo control of the servo motors that drive the joint axes of the robot 10 based on commands from the operation program 208 or the external input device 40 and feedback information from position sensors (encoders, etc.) 11 arranged on each axis of the robot 10, thereby moving a predetermined control part of the robot 10 in accordance with the commands.

[0021] The region setting unit 202 provides a function for setting a designated region (operation region or restriction region). The functions provided by the region setting unit 202 may include a function for receiving a setting input for the designated region from an external device or a user and storing the input in a storage unit. For example, the region setting unit 202 may be configured to receive the setting input for the operation region or restriction region via a UI screen for setting the operation region or restriction region. In this case, the region setting unit 202 may be configured to display the UI screen on the display screen of the display unit 43 of the external input device 40 and receive an operation input for the UI screen via an operation on the operation unit 44. In this case, the setting input may include information about the three-dimensional position and size of the designated region. The region setting unit 202 provides information about the designated region to the collision detection unit 205.

[0022] The stop method setting unit 203 provides a function for making settings related to stopping the robot when the robot 10 deviates from the operating area or interferes with the restricted area. The functions provided by the stop method setting unit 203 may include a function for accepting setting input of the stop method from an external device or a user and storing it in the storage unit. The setting input in this case includes, for example, the following items: (1) A reference coordinate system that serves as a reference for detecting the robot's position and direction of movement. (2) Information that associates the robot's movement direction and the type of stop control when collision is detected

[0023] Hereinafter, the types of stop control will be referred to as “stop categories.” Note that a stop category is a classification of the contents of stop control when stopping a robot, and may include, for example, the following: (1) Stop Category 0: The power supply to the robot's servo control is turned off to instantly stop the robot's operation. In Stop Category 0, the servo power supply is turned off while the robot is operating, so the trajectory of the deceleration operation is not controlled. (2) Stop Category 1: After the robot's movement is decelerated to a stop, the robot's servo power is turned off.

[0024] Stop category 0 is used in situations where urgency is high. Stop category 0 stops the robot faster than stop category 1, but places a greater load on the robot mechanical unit. The stop method setting unit 203 may have a function of accepting input for setting the 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 to accept operation input for the UI screen via an operation on the operation unit 44.

[0025] The position calculation unit 204 calculates the position of the robot 10 by kinematic calculation based on position information from the position sensors 11 of each axis of the robot 10. Here, the "robot position" as the target of position calculation may include the positions of control parts such as the TCP (tool center point), as well as the positions of all parts on the robot, such as the positions of specific arms and joints on the robot. Furthermore, if the robot 10 is equipped with a tool (end effector), the position on the tool may also be subject to position calculation as the "robot position." The position calculation may also include calculation of the orientation. The position calculation unit 204 provides the calculated position of the robot 10 to the interference detection unit 205.

[0026] The interference detection unit 205 detects whether the robot 10 has interfered with the outer surface of the operating area or the restricted area based on the position of the robot 10 provided by the position calculation unit 204 and the position information of the operating area or the restricted area set in the area setting unit 202.

[0027] The movement direction detection unit 206 functions as a movement state detection unit that detects the movement 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 interference is detected by the interference detection unit 205. The movement direction of the robot can be obtained based on the position information of the robot 10 calculated at a predetermined cycle by the position calculation unit 204. The coordinate system used as a reference when determining the movement direction of the robot 10 is acquired from the area setting unit 202 or the stop method setting unit 203.

[0028] The stopping unit 207 stops the robot 10 according to the stopping category corresponding to the direction of movement of the robot 10 when interference between the robot 10 and the outer surface of the movement area or the restricted area is detected, based on the setting information set via the stopping method setting unit 203.

[0029] A specific example of the operation of the stop control when the motion area is set as the designated area will be described with reference to FIGS. 5A and 5B. In the situation shown in FIGS. 5A and 5B, a motion area R101 is set for the robot 10, and the operator OP is located to the right of the front of the robot 10 in the figure. In this situation, if the robot 10 deviates from the motion area R101, and the robot 10 is moving toward the operator OP, the robot 10 is stopped in stop category 0 to prioritize safety. In other cases, the robot 10 is stopped in stop category 1, taking into account the load on the robot 10. In this example, a world coordinate system C1 fixed to the base of the robot 10 is used as the reference coordinate system used to detect the motion direction. For ease of explanation, the directions of the coordinate axes of the world coordinate system C1 are indicated in the upper right corner of FIG. 5A (as well as other similar figures). In this example, the motion direction of the robot 10 is set to stop category 0 in the +Y direction, and stop category 1 in other directions.

[0030] 5A shows a state when the robot 10 interferes with the outer surface of the operating area R101. In this case, the operating direction of the robot 10 when it interferes with the outer surface of the operating area R101 is determined to be the +Y direction, and the robot 10 is stopped in stop category 0. In this case, the robot 10 moves in a direction approaching the operator OP and deviates from the operating area R101, so the robot 10 is brought to an emergency stop in stop category 0 to reliably ensure the safety of the operator OP.

[0031] In the case of Fig. 5B, the movement direction of the robot 10 when it interferes with the outer surface of the operating area R101 is determined to be the -Y direction, and the robot 10 is stopped in stop category 1. From the positional relationship between the robot 10 and the operator OP in Fig. 5B, if the robot 10 moves in the -Y direction and deviates from the operating area R101, the safety of the operator OP is ensured. Therefore, in this case, by stopping the robot 10 in stop category 1, the load on the robot 10 can be reduced while ensuring the safety of the operator OP.

[0032] A specific example of the operation of stop control when a restricted area is set as the specified area will be described with reference to Figures 6A and 6B. In the situation of Figures 6A and 6B, restricted areas R102 and R103 are set for the robot 10, and the operator OP is located on the right side in front of the robot 10 in the figures. Note that the restricted area R102 in Figure 6A and the restricted area R103 in Figure 6B are located in different positions.

[0033] In this situation, when the robot 10 enters the restricted area, if the robot 10 is moving in a direction approaching the operator OP, it is stopped in stop category 0, emphasizing the urgency of the situation, and in other cases it is stopped in stop category 1, taking into account the burden on the robot 10. In this example, a world coordinate system C1 fixed to the base of the robot 10 is used as the reference coordinate system used to detect the movement direction. In this example, the movement direction of the robot 10 is set to stop category 0 when in the +Y direction, and stop category 1 when in other directions.

[0034] 6A shows a situation in which the robot 10 has entered the restricted area R102 and interference has been detected. In this case, the robot 10 is moving in the +Y direction, so stop control is performed using stop category 0. In this case, the robot 10 is moving in a direction approaching the operator OP, so an emergency stop is performed using stop category 0, ensuring the safety of the operator.

[0035] In the situation of Fig. 6B, when the robot 10 interferes with the restricted area R103, the robot 10 is moving in the -Y direction, and therefore the robot 10 is stopped in stop category 1. From the positional relationship between the robot 10 and the operator OP in Fig. 6B, if the robot 10 moves in the -Y direction and enters the restricted area R103, the safety of the operator OP is ensured. Therefore, in this case, by stopping the robot in stop category 1, the load on the robot can be reduced while ensuring the safety of the operator OP.

[0036] The reference coordinate system used as the basis for detecting the movement direction can be not only the world coordinate system as in the example described above, but also a user coordinate system arbitrarily set by the user. Referring to FIGS. 7A and 7B, an example of operation will be described when a coordinate system set by the user (hereinafter referred to as the user coordinate system) is used as the reference coordinate system used for detecting the movement direction. The user coordinate system is, for example, a coordinate system set for a workpiece within the movement area or a workbench on which the workpiece is placed. FIGS. 7A and 7B show an example of operation when a movement area R101 is set as the specified area. The operator OP is positioned to the left of the front of the robot 10 in the figure. In this situation, if the robot 10 deviates from the movement area and moves toward the operator OP, the robot 10 is stopped under stop category 0, emphasizing urgency. Otherwise, the robot 10 is stopped under stop category 1, taking into account the load on the robot 10. In this example, the movement direction of the robot 10 in the +Y direction of the user coordinate system U1 is set to stop category 0, and in other directions, it is set to stop category 1.

[0037] 7A shows a state when the robot 10 interferes with the outer surface of the operating area R101. In the case of FIG. 7A, the operating direction of the robot 10 when it interferes with the outer surface of the operating area R101 is determined to be the -Y direction, and the robot 10 is stopped in stop category 1. From the positional relationship between the robot 10 and the operator OP in FIG. 7A, if the robot 10 moves in the -Y direction and deviates from the operating range R101, the safety of the operator OP is ensured. Therefore, in this case, by stopping the robot in stop category 1, it is possible to reduce the load on the robot while ensuring the safety of the operator.

[0038] 7B shows a state when the robot 10 interferes with the outer surface of the operating area R101. In this case, the operating direction of the robot 10 when it interferes with the outer surface of the operating area R101 is determined to be the +Y direction, and the robot 10 is stopped in stop category 0. In this case, the robot 10 moves in a direction approaching the operator OP and deviates from the operating area R101, so the robot 10 is brought to an emergency stop in stop category 0, thereby ensuring the safety of the operator.

[0039] Since the user coordinate system is a coordinate system that is easy for users to understand intuitively, making it possible to set the user coordinate system as the reference coordinate system for safety functions can make it easier for users to intuitively understand how to set the stopping method and understand the direction of robot movement.

[0040] 8 is a diagram showing a first example of a UI (user interface) screen for setting a designated area and a stop method. The UI screen 300 is provided as a function of the area setting unit 202 and the stop method setting unit 203. The UI screen 300 is displayed on the display screen of the display unit 43 of the external input device 40, and an operation input to the UI screen may be accepted via an operation to the operation unit 44.

[0041] The UI screen 300 has an area specification field 301 in which either an operating area or a restricted area can be specified as the specified area. Fig. 8 shows an example in which an operating area is specified as the specified area. For example, the position of the operating area can be set in the position specification field 304. For example, when setting a rectangular parallelepiped area, a diagonal position is specified in the position specification field 304. In the target model specification field 302, a robot model for interference check such as that shown in Fig. 2 can be specified.

[0042] The UI screen 310 further has a specification field 305 for specifying a stop method, a specification field 306 for specifying a movement direction of stop category 0, a specification field 306 for specifying a movement direction when detecting a movement direction, and a specification field 303 for specifying a reference coordinate system when detecting a movement direction. In this example, stop category 0 applies only to the direction specified in specification field 306 for specifying the direction of stop category 0, and the stop category specified in stop method specification field 305 applies to other directions. In the case of the settings in FIG. 8 , only the +X direction is stop category 0, and all other directions are stopped in stop category 1. Note that the options that can be specified in stop category specification field 306 may be "none," "+X," "+Y," "+Z," "-X," "-Y," or "-Z."

[0043] Fig. 9 is a diagram showing a second example of a UI screen for setting the designated area and the stop method. These UI screens are provided as functions by the area setting unit 202 and the stop method setting unit 203. These UI screens are displayed on the display screen of the display unit 43 of the external input device 40, and operation inputs to the UI screens may be accepted via operations on the operation unit 44. The UI screen 310 shown on the left side of Fig. 9 mainly relates to setting the designated area. The UI screen 320 shown on the right side of Fig. 9 is a setting screen for detailed settings of the stop method.

[0044] The UI screen 310 has an area specification field 311 in which either an operating area or a restricted area can be specified as the specified area. Fig. 9 shows an example in which an operating area is specified as the specified area. For example, the position of the operating area can be set in the position specification field 312. For example, when setting a rectangular parallelepiped area, a diagonal position is specified in the position specification field 312. In the target model specification field 313, a robot model for interference check such as that shown in Fig. 2 can be specified.

[0045] The UI screen 310 includes a stop method specification field 314. By selecting the stop method specification field 314, a UI screen 320 for setting detailed settings of the stop method can be called up. As shown in FIG. 9, the UI screen 320 is configured so that different stop methods can be set depending on the movement direction. The UI screen 320 displays the following for each stop method: (1) Stop Category (Specify column 321) (2) Robot movement direction when interference occurs (specify field 322) (3) Reference coordinate system for detecting the direction of movement (specify field 323) can be set.

[0046] On the UI screen 320 of FIG. 9, the following four stop methods are set. (1) Stop method 1: Stop category 0, movement direction is +X direction, reference coordinate system is world coordinate system (2) Stop method 2: Stop category 0, movement direction is +Y direction, reference coordinate system is user coordinate system 1 (3) Stop method 3: Do not stop, operation direction is +Z direction, reference coordinate system is user coordinate system 2 (4) Stop method 4: Stop category 1, movement direction is -X direction, reference coordinate system is user coordinate system 3

[0047] The components of the movement direction of the robot 10 when the robot 10 interferes with the outer surface of the movement area or the restricted area may be detected, and the stop category may be determined based on the detected components. When multiple components are detected as the movement direction, the robot control device 20 can determine the stop category using the following procedure. (A1) Detect interference between the robot and the outer surface of the operating area or the restricted area. (A2) Detect multiple components of the movement direction. (A3) The stop category set for all the movement direction components detected in step (A2) is obtained. (A4) The stop category with the highest priority among the stop categories obtained in step (A3) is adopted.

[0048] Specific determination of a stop category based on the above procedure will be described with reference to Fig. 10 and Fig. 11. Fig. 10 shows a situation in which two components are obtained as the movement direction when the robot 10 deviates from the movement area R101. In the situation in Fig. 10, a +Y component and a -X component are obtained as the components of the movement direction V of the robot. Fig. 11 shows the setting contents (UI screen 320A) of the stop method used in this example.

[0049] The movement direction components obtained in the situation of FIG. 10 are +Y and −X components, and therefore, as shown in columns 325 and 326 in FIG. 11, the stop categories obtained in step (A3) above are stop category 0 and stop category 1. As for the priority of the stop categories, for example, a higher priority is assigned to a stop category that is more important from a safety perspective. In this case, stop category 0 has a higher priority than stop category 1. Therefore, in this case, stop category 0 is adopted in step (A4), and the robot 10 is stopped in stop category 0. As a result, if the robot 10 moves in a direction approaching the operator OP and deviates from the movement region R101 as shown in FIG. 10, the robot 10 is brought to an emergency stop by stop category 0, and the safety of the operator OP is ensured.

[0050] When determining the interference between the robot 10 and the outer surface of the motion area or the restricted area by calculation, a robot model 101M (see FIG. 2) covering the robot 10 may be used to calculate whether or not interference between the robot model 101M and the outer surface of the motion area or the restricted area occurs, as shown in FIG. 12. FIG. 12 shows a situation in which a state is detected in which the robot model 101M set in the robot 10 interferes with the outer surface of the motion area R101 (the robot model 101M deviates from the motion area R101). In this way, by detecting interference using the robot model 101M, the calculation load can be reduced.

[0051] Second embodiment 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 which of the surfaces constituting the outer surface of the operating area or restricted area the robot 10 is interfering with, and to set a stop category according to the surface with which the interference has occurred.

[0052] Fig. 13 is a functional block diagram of a robot control device 20A according to the second embodiment. In the functional block diagram of Fig. 13, the same functional blocks as those of the robot control device 20 according to the first embodiment shown in Fig. 4 are assigned the same reference numerals. As shown in Fig. 13, the robot control device 20A has an operation control unit 201, an area setting unit 202, a stopping method setting unit 203A, a position calculation unit 204, an interference detection unit 205, an interference surface detection unit 209, and a stopping unit 207A.

[0053] The stop method setting unit 203A can provide a function for setting a stop category for each outer surface of the motion area or the restricted area. The interfering surface detection unit 209 functions as a motion state detection unit that detects the motion state of the robot 10 when interference is detected by the interference detection unit 205. When interference between the robot 10 and the outer surface of the motion area or the restricted area is detected, the interfering surface detection unit 209 detects which outer surface of the motion area or the restricted area the robot 10 has interfered with.

[0054] The stopping unit 207A stops the robot 10 according to the stopping category set for the surface detected by the interfering surface detection unit 209.

[0055] When a stop category is set for each face of the specified area, identification information may be assigned to each face as shown in Figures 14 and 15. Figure 14 shows an example in which a rectangular parallelepiped operating area R1 is set and identification numbers 1 to 6 are assigned to the front, right side, back, left side, bottom, and top faces, respectively. In Figure 14, the identification numbers 1 to 6 are indicated by numbers in circles.

[0056] FIG. 15 shows a state in which an octagonal prism-shaped operating area R2 is set around the robot, with identification numbers 1 to 8 assigned to the eight side surfaces and identification numbers 9 and 10 assigned to the top and bottom surfaces, respectively. In FIG. 15, the identification numbers 1 to 10 are indicated by numbers in circles. The interfering surface detection unit 209 and the stopping unit 207A can identify each surface on the outer surface of the designated area using these identification numbers. In this way, by assigning identification information to each surface on the outer surface that constitutes the designated area and enabling the surfaces to be identified, it is possible to efficiently specify a stop category for each surface, even when the designated area is set as a polyhedron.

[0057] Figure 16A shows a rectangular parallelepiped operating area R101, with the bottom side of the figure being the front side, and shows a state in which identification numbers 1 to 4 have been assigned to the front, right side, back, and left side of the operating area R101, respectively. In Figure 16A (as well as other similar figures), the identification numbers are each indicated by a number in a circle. In this example, stop category 0 is set to the side with identification number 2 (right side), and stop category 1 is set to the other sides.

[0058] 16A illustrates a situation in which the robot 10 deviates from the operating area R101 while interfering with the face (right side face) with identification number 2. In this case, the robot 10 is stopped in stop category 0, which is assigned to the face (right side face) with identification number 2. In this case, the robot 10 moves in a direction approaching the operator OP and deviates from the operating area R101, so the safety of the operator OP is reliably ensured.

[0059] 16B illustrates a situation in which the robot 10 deviates from the operating area R101 while interfering with the face (left side) with identification number 4. In this case, the robot 10 is stopped in stop category 1, which is assigned to the face (left side) with identification number 4. In this case, the robot 10 moves away from the operator OP and deviates from the operating area R101, so the safety of the operator OP is maintained and load on the robot 10 is avoided.

[0060] 17A and 17B show an example of operation when assigning identification numbers to each surface that constitutes the outer surface of a restricted area. Here, for restricted areas R102 and R103, the bottom side in the figure is the front side, and identification numbers 1 to 4 are assigned to the front, right side, back, and left side, respectively. In this case, stop category 0 is set to the surface with identification number 4 (left side), and stop category 1 is set to the other surfaces.

[0061] 17A shows a situation in which the robot 10 interferes with the face (left side) of the restricted area R102 with identification number 4 and enters the restricted area R102. In this case, the robot 10 is stopped in stop category 0, which is set for the face (left side) with identification number 4. In the situation in FIG. 17A, the operator OP is on the right side of the restricted area R102. Therefore, in a situation in which the robot 10 enters the restricted area R102 so as to come close to the operator OP, as shown in FIG. 17A, the robot 10 is stopped in stop category 0, and the safety of the operator OP is reliably ensured.

[0062] 17B shows a situation in which the robot 10 interferes with the face (right side) of the restricted area R103 with identification number 2 and enters the restricted area R103. In this case, the robot 10 is stopped in stop category 1, which is set for the face (right side) with identification number 2. In the situation in FIG. 17B, the operator OP is on the right side of the restricted area R103. Therefore, in a situation in which the robot 10 enters the restricted area R103 so as to move away from the operator OP, as shown in FIG. 17B, the robot 10 is stopped in stop category 1, thereby avoiding a load on the robot 10 while maintaining the safety of the operator OP.

[0063] Fig. 18 is a diagram showing an example of a UI (user interface) screen for setting a designated area and a stop method in the second embodiment. These UI screens are provided as functions by the area setting unit 202 and the stop method setting unit 203A. These UI screens are displayed on the display screen of the display unit 43 of the external input device 40, and operation inputs to the UI screens may be accepted via operations on the operation unit 44. The UI screen 410 shown on the left side of Fig. 18 mainly relates to setting the designated area. The UI screen 420 shown on the right side of Fig. 18 is a setting screen for detailed settings of the stop method.

[0064] The UI screen 410 has designation fields similar to the designation fields 311 to 314 in the UI screen 310 shown in FIG. 9. The UI screen 410 includes a designation field 411 for a stop method. For example, by performing an operation to select the designation field 411, a UI screen 420 for setting the details of the stop method can be called up. As shown in FIG. 18, the UI screen 420 is configured so that a plurality of stop methods can be set depending on the surface with which the robot interferes. The UI screen 420 has the following designation fields for each stop method: (1) Stop Category (Specify column 421) (2) The surface where the robot interferes (specify field 422) can be set. In this way, by configuring the stop method to be set by face, the setting contents can be simplified. In addition, the operator can set the stop method in an intuitive and easy-to-understand manner, since all that is required is to associate each face in the specified area with a stop category.

[0065] On the UI screen 420 of FIG. 18, four stop methods are set, and the settings are as follows. Stop method 1: Designated surface 1 (identification number 1), stop category 0 Stop method 2: Designated surface 2 (identification number 2), stop category 0 Stop method 3: Designated surface 3 (identification number 3), do not stop Stop method 4: Designated surface 4 (identification number 4), stop category 1

[0066] Third embodiment 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 be able to set whether a restricted area is valid or invalid, to validate the restricted area when the operator enters the restricted area, and to stop the robot 10 in a stop category that corresponds to the direction of movement of the robot 10 within the restricted area at that time.

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

[0068] Fig. 19 is a functional block diagram of a robot control device 20B according to the third embodiment. In Fig. 19, the same reference numerals are assigned to functional blocks that are the same as those of the robot control device 20 according to the first embodiment. As shown in Fig. 19, the robot control device 20B includes, as functional blocks related to safety functions, an area setting unit 202B, a stop method setting unit 203, a position calculation unit 204, an interference detection unit 205B, a movement direction detection unit 206, and a stop unit 207. A detection signal from a sensor 80 for detecting that a person has entered a restricted area is input to the interference detection unit 205B.

[0069] The area setting unit 202B is configured to provide a function for setting the specified area as valid or invalid in addition to the function of the area setting unit 202 according to the first embodiment. The interference detection unit 205B determines that the restricted area is valid when the sensor 80 detects that a person has entered the restricted area, and notifies the movement direction detection unit 206 when interference between the robot 10 and the restricted area is detected in that situation. On the other hand, when the sensor 80 does not detect that a person has entered the restricted area, the interference detection unit 205B determines that the restricted area is invalid.

[0070] The movement direction detection unit 206 functions as a movement state detection unit that detects the movement 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 restricted area in a situation where interference between the robot 10 and the restricted area is detected. The stopping unit 207 stops the robot 10 by performing stop control according to the movement direction of the robot 10 when a person enters the restricted area in a situation where interference between the robot 10 and the restricted area is detected.

[0071] A specific example of operation will be described with reference to Figures 20A to 20C. In Figures 20A to 20C, a restricted area R110 is set in front of the robot 10, and the operator OP may enter the restricted area R110. In this example, it is assumed that a world coordinate system C1 set at the base of the robot 10 is used as a reference, and stop category 0 is set for the +X direction as the movement direction, and stop category 1 is set for the -X direction as the movement direction.

[0072] 20A, the operator OP has not entered the restricted area R110, and therefore the restricted area R110 is invalid. In this case, the interference detection unit 205B considers the restricted area R110 to be invalid and does not check for interference between the robot 10 and the restricted area R110. In this example, stop control is not executed when the robot 10 interferes with the restricted area R110, but the safety of the operator OP is maintained and the load on the robot 10 due to stop control is avoided.

[0073] 20B shows a situation in which the operator OP has entered the restricted area R110. In this case, the sensor 80 detects the operator OP's entry into the restricted area R110, and the restricted area R110 is activated. In this situation, when the restricted area R110 is activated, the robot 10 has entered the restricted area R110 and its movement direction is the +X direction, so the robot 10 is brought to an emergency stop according to stop category 0. This reliably ensures the safety of the operator OP.

[0074] 20C shows a situation in which the operator OP has entered the restricted area R110. In this case, the sensor 80 detects the operator OP's entry into the restricted area R110, and the restricted area R110 is activated. In this situation, when the restricted area R110 is activated, the robot 10 has entered the restricted area R110 and its movement direction is the -X direction, so the robot 10 is stopped by stop category 1. In this case, the robot 10 is moving away from the operator OP, so the load on the robot 10 is reduced while the safety of the operator OP is maintained.

[0075] FIG. 21 shows an example of a UI screen used in the setting in the third embodiment. The UI screen 300A is provided as a function by the area setting unit 202B and the stop method setting unit 203. The UI screen 300A is displayed on the display screen of the display unit 43 of the external input device 40, and an operation input to the UI screen 300A may be accepted via an operation on the operation unit 44. The UI screen 300A used in this embodiment may be realized by adding a designation field 309 for designating a signal for enabling / disabling the designated area to the UI screen 300 in the first embodiment described with reference to FIG. 8. The UI screen 300A shows an example in which a setting is made to designate a signal from a safety mat as a signal for disabling the restricted area. The interference detection unit 205B is configured to designate a signal from a safety mat as a signal for disabling the restricted area in the designation field 309Based on the settings in step 10, it is possible to specify the state of the signal from the sensor 80 that will cause the restricted area to be invalid. Note that on the UI screen 300A, the specification field 305A for specifying the stop method is configured to specify the direction of stop category 0.

[0076] In this embodiment, an example of an operation has been described in which a restricted area is set as the designated area, and stop control is performed by disabling or enabling the restricted area based on a signal from the sensor 80. However, a configuration may also be adopted in which a motion area is set as the designated area, the sensor 80 detects intrusion of a person into the motion area, and stop control is performed by disabling or enabling the motion area based on a signal from the sensor 80. Even in this case, as in the above embodiment, stop control can be achieved that reduces the burden on the robot while ensuring the safety of the operator.

[0077] In this embodiment, an example of operation has been described in which the area in which the robot is stopped can be set to be valid or invalid in accordance with the stop category corresponding to the direction of movement of the robot 10 when interference with the outer surface of the motion area or the restricted area is detected. However, as shown in embodiment 2, when interference between the robot 10 and the outer surface of the motion area or the restricted area is detected, it is detected which surface of the motion area or the restricted area the robot 10 has interfered with, and the robot 10 is stopped according to the stop category set for the detected surface. It is also possible to configure the area to be valid or invalid, and to perform stop control by invalidating or enabling the motion area based on a signal from the sensor 80. Even in this case, as in the above embodiment, stop control can be achieved that reduces the burden on the robot while ensuring the safety of the operator.

[0078] As described above, according to each embodiment, when interference with the outer surface of the robot's operating area or a restricted area is detected, appropriate stop control can be applied depending on the operating state of the robot, thereby realizing stop control that reduces the load on the robot mechanism while ensuring the safety of the operator.

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

[0080] For example, the functional layouts shown in the functional block diagrams (FIGS. 4, 13, and 19) of the robot control device in the above-described embodiments are merely examples, and various modifications are possible with regard to the layout of these functional blocks. For example, a configuration example is possible in which at least some of the functional blocks related to safety functions (e.g., an area setting unit, a stop method setting unit) arranged in the robot control device are arranged in a teaching pendant as an external input device. In this case, the overall function combining the functions of the teaching pendant as an external input device and the functions of the robot control device can also be defined as the robot control device.

[0081] In detecting interference between the robot and the outer surface of the motion area or the restricted area, if interference between any part (which may include all parts from the base of the robot to the tool part) constituting the robot (or the robot model covering the robot) and the outer surface of the motion area or the restricted area is detected, it goes without saying that it can be said that "interference between the robot and the outer surface of the motion area or the restricted area has been detected." Also, in detecting the movement direction or interfering surface when interference between the robot and the outer surface of the motion area or the restricted area is detected, it goes without saying that "the movement direction of the robot and the interfering surface with the robot are detected" if interference between any part (which may include all parts from the base of the robot to the tool part) constituting the robot (or the robot model covering the robot) and the outer surface of the motion area or the restricted area is detected.

[0082] The functional blocks of the robot control device shown in Figures 4, 13, and 19 may be realized by the processor of the robot control device executing various software stored in a storage device, or may be realized by a configuration mainly based on hardware such as an ASIC (Application Specific Integrated Circuit).

[0083] The program that executes various processes such as the procedure for determining the stop category in the above-described embodiment can be recorded on various computer-readable recording media (e.g., semiconductor memory such as ROM, EEPROM, flash memory, magnetic recording media, optical discs such as CD-ROM, DVD-ROM, etc.). [Explanation of symbols]

[0084] 10. Robot 11 Position Sensor 20, 20A, 20B Robot control device 21 processors 22 Memory 23 Input / Output Interface 24 Control section 40 External input device 41 processors 42 memory 43 Display section 44 Control section 45 Input / Output Interface 100 Robot Systems 101M Robot Model 201 Motion control unit 202, 202B area setting section 203, 203A, 203B Stop method setting section 204 Position calculation section 205, 205B Interference detection unit 206 Motion direction detection unit 207, 207A Stop part 208 Operation Program 209 Interference surface detection unit 310A, 320, 320A, 410, 420 UI screen

Claims

1. A robot control device for controlling a robot, an area setting unit for setting an operating area in which the robot can operate or a restricted area in which the robot cannot enter; a position calculation unit that calculates the position of the robot; an interference detection unit that detects interference between the robot and the outer surface of the operating area or the restricted area based on the calculated position of the robot; a motion state detection unit that detects a motion state of the robot when the interference is detected; a stop unit that stops the robot by stop control according to the detected motion state; A robot control device comprising:

2. a stop method setting unit for setting stop control according to the operating state of the robot; The robot control device according to claim 1 , wherein the stopping unit stops the robot by a stop control that corresponds to the operating state set in the stopping method setting unit.

3. the motion state detection unit includes a motion direction detection unit that detects a motion direction of the robot when the interference is detected, The robot control device according to claim 2 , wherein the stopping unit stops the robot by performing stop control according to the movement direction of the robot when the interference is detected.

4. The robot control device according to claim 3 , wherein the stop method setting unit is configured to be able to set different stop controls for each movement direction of the robot.

5. A robot control device for controlling a robot, an area setting unit for setting an operating area in which the robot can operate or a restricted area in which the robot cannot enter; a position calculation unit that calculates the position of the robot; an interference detection unit that detects interference between the robot and the outer surface of the operating area or the restricted area based on the calculated position of the robot; a motion state detection unit that detects a motion state of the robot when the interference is detected; a stop unit that stops the robot by stop control according to the detected operating state; a stop method setting unit for setting stop control according to the operating state of the robot, the stopping unit stops the robot by stop control according to the operation state set in the stop method setting unit, the motion state detection unit includes a motion direction detection unit that detects a motion direction of the robot when the interference is detected, the stopping unit stops the robot by performing stop control according to the movement direction of the robot when the interference is detected, The robot control device, wherein the stop method setting unit is configured to be able to set a coordinate system that serves as a reference when the movement direction detection unit detects the movement direction of the robot.

6. the motion state detection unit includes an interfering surface detection unit that detects, when the interference is detected, which surface of a plurality of surfaces that constitute the outer surface of the motion area or the outer surface of the restricted area the robot has interfered with; The robot control device according to claim 2 , wherein when the interference is detected, the stopping unit stops the robot by performing stop control according to the surface with which the robot interferes, among the plurality of surfaces.

7. A robot control device for controlling a robot, an area setting unit for setting an operating area in which the robot can operate or a restricted area in which the robot cannot enter; a position calculation unit that calculates the position of the robot; an interference detection unit that detects interference between the robot and the outer surface of the operating area or the restricted area based on the calculated position of the robot; a motion state detection unit that detects a motion state of the robot when the interference is detected; a stop unit that stops the robot by stop control according to the detected operating state; a stop method setting unit for setting stop control according to the operating state of the robot, the stopping unit stops the robot by stop control according to the operation state set in the stop method setting unit, the motion state detection unit includes an interfering surface detection unit that detects, when the interference is detected, which surface of a plurality of surfaces that constitute the outer surface of the motion area or the outer surface of the restricted area the robot has interfered with; the stopping unit, when the interference is detected, stops the robot by performing stop control according to the surface with which the robot interferes among the plurality of surfaces; The robot control device, wherein the stop method setting unit is configured to be able to set different stop controls for each surface that constitutes the outer surface of the motion area or the outer surface of the restriction area.

8. the region setting unit is configured to be able to specify a signal for switching between enabling and disabling the operation region or the restriction region, the interference detection unit is configured to detect the interference when the operating region or the restricted region is valid based on the signal; The robot control device according to claim 1, wherein the stopping unit stops the robot by performing stop control according to the operating state of the robot when the interference is detected when the operating area or the restricted area is valid based on the signal.

9. 9. The robot control device according to claim 8, wherein the area setting unit is configured to be able to specify a detection signal from a sensor for detecting that a person has entered the operation area or the restricted area as a signal for switching between enabling and disabling the operation area or the restricted area.

10. The robot control device according to claim 2 , wherein the stop method setting unit is configured to accept a setting of stop control according to an operating state of the robot via a user interface screen.

11. The robot control device according to claim 1 , wherein the area setting unit is configured to accept settings regarding the operation area or the restricted area via a user interface screen.

Images