Robot system and robot control device

Abstract

A robot system (100) is provided, comprising a robot (10), a robot control device (50) that executes a robot program and controls the robot, and a force detection unit that detects a force acting on the robot. The robot control device (50) comprises: a detection unit (154) that, based on the robot program, determines an operating mode of force control executed by the robot program using the force detection unit; and a force control setting unit (155) that sets operating settings for force control in accordance with the operating mode for force control determined by the detection unit.

Description

Area

[0001] The present invention relates to a robot system and a robot control device. State of the art

[0002] A robot system in which a robot is controlled to perform a predetermined work while tracking a workpiece carried on a conveyor is known.

[0003] Patent Application Publication No. 1 (PTL) describes a robot system including a robot 100, an end effector 200, a robot controller 300, a camera 400, and a conveyor 500 (paragraph 0033). Patent Application Publication No. 1 further describes as follows: "A control signal generation unit 310 generates a position control signal indicating a target position at which the end effector 200 is to be positioned and outputs the signal to a position control unit 320. When receiving an instruction to perform tracking control from a user, the control signal generation unit 310 outputs a signal indicating that tracking control is to be performed to the position control unit 320. When receiving an instruction to perform force control from the user, the control signal generation unit 310 outputs a control signal indicating that force control is to be performed to the position control unit 320." (paragraph 0042).

[0004] PTL 2 describes as follows: "A control method for a robot 1 that performs work on a target object W conveyed by a conveyor 50 using an end effector 20, the method including: calculating a target position of the end effector 20 based on a position of the target object W; calculating an amount of tracking correction for correcting the target position in accordance with an amount of conveyance of the target object W; causing the end effector 20 to follow the target object W based on the target position and the amount of tracking correction; detecting an acting force from the target object W acting on the end effector 20 using a force sensor P; calculating an amount of force control correction for correcting the target position so that the acting force agrees with a target force;and controlling the acting force to be a predetermined target force by driving a manipulator 10 based on the amount of force control correction." (SUMMARY).; List of citationsPatent literature [PTL 1] Unexamined Japanese Patent Publication (Kokai) No. 2018-171665 A [PTL 2] Unexamined Japanese Patent Publication (Kokai) No. 2020-189392 A OverviewTechnical task

[0005] When an operator creates a robot program for controlling a robot to perform work using force control while tracking a workpiece conveyed on a conveyor, the operator must add statements defining a force control operating mode to the robot program before and after an instruction for calling the force control. Such programming is tedious and can cause human error, such as missetting. A robot system and a robot controller that enable automatic setting of the force control operating mode are desirable. Technical solution

[0006] One aspect of the present disclosure is a robot system including: a robot; a robot controller configured to execute a robot program and control the robot; and a force detection unit configured to detect a force acting on the robot, wherein the robot controller includes: a determination unit configured to determine, based on the robot program, an operation mode of force control using the force detection unit, wherein the force control is executed in the robot program; and a force control setting unit configured to perform setting of the force control according to the operation mode of force control determined by the determination unit.

[0007] Another aspect of the present disclosure is a robot control device for executing a robot program and controlling a robot, the robot control device including: a determination unit configured to determine, based on the robot program, an operation mode of a force controller using a force detection unit, wherein the force controller is executed in the robot program; and a force controller setting unit configured to perform setting of the force controller according to the operation mode of the force controller determined by the determination unit. Advantageous effects of the invention

[0008] The above-mentioned configurations enable automatic detection of an operating mode of the force control and automatic operating setting of the force control.

[0009] 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. Short description of the drawings Fig. 1 is a diagram illustrating a configuration of a robot system according to an embodiment. Fig. Figure 2 is a graphical representation of a functional configuration of the robot system. Fig. 3 is a flowchart illustrating determination processing of the operation mode of a force controller. Fig. Figure 4 is a conceptual diagram illustrating a mapping between a robot program and a tracking plan. Fig. 5 is an example of a confirmation screen of an association between a robot program and a tracking plan. Fig. 6 is a diagram showing a setting example of a work area. Fig. Figure 7 is a graphical representation showing an example of automatic setting of a work area. Fig. 8 is a graph showing an example of resetting a work area by excluding an obstacle. Fig. 9 is a diagram for illustrating detection of a state of the robot leaving a work area. Fig. 10 is a flowchart illustrating a flow of processing including setting a force control mode and setting and monitoring a range. Description of the embodiments

[0010] Next, embodiments of the present disclosure will be described with reference to the drawings. In the referenced drawings, similar components or functional parts are designated by similar reference numerals. For ease of understanding, the drawings may use different scales. Furthermore, configurations illustrated in the drawings are examples of an implementation of the present invention, and the present invention is not limited to the illustrated configurations.

[0011] Fig. 1 is a diagram illustrating a configuration of a robot system 100 according to an embodiment. As shown in Fig. 1, the robot system 100 includes a conveyor 120 that conveys a workpiece, a robot 10, a robot controller 50 that controls the robot 10, a visual sensor 71, and a visual data processing device 70 that controls the visual sensor 71. The visual data processing device 70 is connected to the robot controller 50. The conveyor 120 includes a pulse encoder 121 as a sensor for detecting an amount of movement of a workpiece by the conveyor 120. For example, the visual sensor 71 is attached to a work site and serves to monitor a work area, etc. A stationary sensor 80 for detecting a workpiece is arranged on the conveyor 120.The stationary sensor 80 may, for example, be a sensor that includes a light-emitting unit and a light-receiving unit, and detects a target object passing between the light-emitting unit and the light-receiving unit. Note that some of the components constituting the robot system 100 (an operation panel 20 and a display device 40) (see FIG. Fig. 2)), in Fig. 1 is omitted.

[0012] The robot 10 can perform a desired task using an end effector attached to the wrist of the arm tip. The end effector is an external device that can be replaced according to the purpose and is, for example, a hand, a welding gun, or a tool. Fig. 1 shows an example of using a hand 30 as an end effector.

[0013] A force sensor 60, as a force detection unit that detects a force (an external force) acting on the robot 10, is provided between the hand 30 as a work tool and the arm tip (the flange) on the robot 10. For example, the force sensor 60 is a six-axis force sensor that detects the forces acting on the work tool in the directions of three axes, namely an x-axis, a y-axis, and a z-axis, as well as the moment about each of the x-axis, the y-axis, and the z-axis. In other words, the force sensor 60 can detect the force and moment generated by contact between a part or the work tool held by the robot 10 and an article. Another type of force detector (such as a torque sensor arranged on each axis of the robot) can be used to detect the force acting on the robot 10.

[0014] The robot 10 in the robot system 100 can perform a predetermined work using force control while tracking a workpiece traveling on the conveyor 120. Fig. 1 illustrates an example of performing a work of fitting a workpiece W1 as a part held by the robot 10 into a workpiece W traveling on the conveyor 120.

[0015] Furthermore, a stationary workbench 110 is provided in the robot system 100. Furthermore, the robot 10 (the robot controller 50) can perform work on a workpiece placed on the stationary workbench in a regular force control mode.

[0016] The robot system 100 according to the present embodiment is configured to be capable of automatically determining, based on a robot program, which of the force control mode executed during a tracking operation and the regular force control mode is to be applied, and performing force control mode setting.

[0017] Fig. 2 is a diagram showing a functional configuration of the robot system 100. The robot controller 50 may have a configuration as a general computer including a processor 51, a storage unit (memory) 52, various input / output interfaces (not shown), an operation unit (not shown), etc. as hardware components. Fig. 2 illustrates functional blocks provided by executing software by the processor 51. As in Fig. 2, the robot controller 50 includes a motion control unit 151, an article recognition unit 152, a movement amount recognition unit 153, a determination unit 154, a force control setting unit 155, and a force control unit 156.

[0018] A robot program for controlling the robot 10 to perform a predetermined work and a tracking plan 300 including setting information related to the tracking operation, the setting information being applied when the robot 10 is controlled to perform a work while tracking a workpiece traveling on the conveyor 120, are registered in the storage unit 52.

[0019] The robot program registered in the storage unit 52 includes a robot program A for performing a predetermined work using force control while causing the robot 10 to perform the tracking operation, and a robot program B for performing a predetermined work on the stationary workbench 110 using force control without the tracking operation.

[0020] The motion control unit 151 controls the movement of the robot 10 in accordance with the robot program. The article recognition unit 152 can, for example, detect a time at which a workpiece conveyed on the conveyor 120 enters a work area based on a signal from the stationary sensor 80. The movement amount detection unit 153 can determine an amount of movement by which the robot 10 is moved during the tracking operation based on a signal from the pulse encoder 121. In addition to the technique of using a signal from the pulse encoder 121, a technique of detecting an amount of movement of a workpiece conveyed on the conveyor 120 by a visual sensor can be used as a technique for detecting an amount of movement of the workpiece.For example, a technique for detecting an amount of movement of a workpiece being conveyed by capturing a movement of the workpiece with a camera mounted on the tip of the robot 10 may also be employed.

[0021] Based on a detection timing of a workpiece detected by the article detection unit 152, information on a movement amount of the workpiece detected by the movement amount detection unit 153, etc., the movement control unit 151 can perform a predetermined work on the workpiece by applying force control while tracking the workpiece traveling on the conveyor device 120.

[0022] The determination unit 154 automatically determines, based on a robot program to be executed, whether the robot program employs an operation mode for performing force control while performing a tracking operation or an operation mode for performing regular force control.

[0023] The force control setting unit 155 switches the force control operation mode between the force control mode executed during a tracking operation and the regular force control mode according to a determination result by the determination unit 154. Since the workpiece W1 comes into contact with the workpiece W during a movement for fitting the workpiece W1 into the workpiece W by the robot 10 in the force control during the tracking operation, it is considered that the robot 10 is likely to generate a vibrational movement. In view of the above, as an example, in the force control during the tracking operation, a setting parameter related to filtering for reducing the vibration of the robot 10 is included.Thus, the force control setting unit 155 sets a force control parameter different between the regular force control mode and the force control mode during a tracking operation during the tracking operation.

[0024] The force control unit 156 performs force control using the force sensor 60 in accordance with force control parameters set by the force control setting unit 155.

[0025] The device 70 for processing visual data may also have a configuration as a computer that includes a processor, a memory, etc. As in Fig. As shown in Figure 2, the visual data processing device 70 includes a visual data processing unit 171 and a storage unit 172. The visual data processing unit 171 may provide a function for performing various types of image processing for recognizing and monitoring an object based on an image captured by the visual sensor 71. For example, the visual data processing unit 171 may provide a function for recognizing a target object in an image based on model data of the target object. The position of the robot 10 when the robot 10 performs work on a workpiece W can be controlled to be corrected using the recognition function of the workpiece W by the visual sensor 71 (the visual data processing device 70).

[0026] The storage unit 172 stores calibration data of the visual sensor 71 and various types of setting information required when executing image processing.

[0027] As in Fig. 2, the robot controller 50 may be further connected to the control panel 20 to perform input of an instruction and output of various types of information to and from the robot controller 50. The robot controller 50 may be further connected to the display device 40 to display various types of information about work performed by the robot 10.

[0028] The manner in which the determination unit 154 determines whether the force control operation mode is force control during the tracking operation or regular force control will be described. When a robot program is created that operates the conveyor device 120 and causes the robot to perform the tracking operation, setting data including various types of setting information related to the tracking operation (referred to as a tracking map) is created. For example, an operator can input setting parameters of the tracking map through a user interface (UI) screen. Such a UI screen can be displayed on a display unit of the operation panel 20. Parameters of the tracking map can have, for example, the following content. • a tracking plan number • a tracking type • a reference coordinate system for tracking • a direction of pursuit • an encoder used for tracking • a scale factor of the encoder

[0029] The "tracking plan number" represents the number of the tracking plan data. When multiple tracking plans are created, each plan can be identified by the number. The "tracking type" is used to indicate the type of movement (such as linear movement or arcuate movement) of the tracking operation. The "reference coordinate system for tracking" indicates a reference coordinate system used when tracking a target object. The "tracking direction" indicates a direction in which tracking is performed. The "encoder used for tracking" indicates an identification number of an encoder as a movement amount detector used in tracking. The "encoder scale factor" indicates a relationship between a pulse number of the encoder and a movement distance of the conveyor.

[0030] A robot program for controlling a robot to perform a job while tracking a workpiece refers to such a tracking plan. Fig. Figure 4 is a conceptual graphical representation of a situation in which a tracking plan 301 is referenced by a robot program 501 for controlling the robot to perform work while tracking a workpiece. For example, the robot program 501 may be configured to reference the tracking plan 301 through a statement that allows data in the tracking plan 301 to be referenced by the robot program 501 (such as a define statement that imports the tracking plan data into a variable).

[0031] Thus, the robot program 501 including the tracking operation is associated with the tracking plan 301. The determination unit 154 determines, based on whether the robot program is associated with the tracking plan, whether the force control operation mode in the robot program is an operation mode of force control executed during a tracking operation or an operation mode of regular force control.

[0032] Fig. Fig. 5 shows an example of a screen when a state is confirmed in which a robot program including a tracking operation is associated with a tracking plan. A screen 351 on the left side in Fig. Figure 5 is a screen example of a robot program that is a confirmation target. The example shows that the program name that is a confirmation target is "TTESTSUB." A screen 352 on the right side of Fig. 5 indicates that the number of a trace plan referred to by the “TTESTSUB” program is “1” (a display field with a character 361 is referred to).

[0033] Fig. 3 is a flowchart illustrating determination processing of the operation mode of force control performed by the robot controller 50. First, the determination unit 154 determines whether a robot program is a robot program that includes the tracking operation based on whether the robot program is associated with a tracking plan as described above (step S1). If it is determined that the robot program is not a robot program that includes the tracking operation (S1: NO), the force control setting unit 155 automatically sets to the regular force control mode by setting force control parameters for performing regular force control at the force control unit 156 (step S2).When it is determined that the robot program is a robot program including the tracking operation (S1: YES), the force control setting unit 155 automatically sets the mode of force control performed during a tracking operation by setting force control parameters for performing the force control during a tracking operation at the force control unit 156 (step S3).

[0034] Functions for setting and monitoring a work area of ​​the robot 10, which are performed by the robot controller 50, are described below. As in Fig. 2, the robot controller 50 includes a range setting unit 161 and a range monitoring unit 162.

[0035] The area setting unit 161 provides a function for setting an area within which the robot 10 is permitted to work. For example, the area setting unit 161 may be configured to accept setting input for setting a work area through a user interface (GUI) screen. The work area may be defined as an area in a world coordinate system defined in a space in which the robot system 100 is arranged. For example, the work area may be defined as an area extending two-dimensionally on a conveying surface of the conveying device 120.

[0036] The area monitoring unit 162 monitors a work area based on an image captured by the visual sensor 71 and detects an obstacle entering the work area and an exit from the work area by the robot 10. The area monitoring unit 162 may provide a monitoring function using an image processing function of the visual data processing unit 171. For example, the area monitoring unit 162 may detect an object entering the work area and an exit from the work area by the robot 10 by comparing pixel values ​​of images successively captured by the visual sensor 71. Another object detection method known in the technical field of object detection in an image may be used.

[0037] Fig. 6 is a schematic diagram showing a state of setting a work area 201 of the robot 10 on the conveyor 120. The robot 10 can perform a predetermined work by force control while tracking a workpiece W3 traveling on the conveyor 120, and can also perform work on a workpiece on the stationary workbench 110 by the regular force control.

[0038] The work area 201 is set on the conveyor 120 in front of the robot 10. The visual sensor 71 is arranged to capture an image in an area including the work area 201. The area monitoring unit 162 monitors the work area based on an image captured by the visual sensor 71.

[0039] If no work area is set, the area setting unit 161 can automatically set a work area in the image pickup area of ​​the visual sensor 71 based on position information of the visual sensor 71 and the robot 10. For example, a work area 202 as shown in Fig. 7, can be automatically set as an area extending two-dimensionally on the conveyor device 120 and in front of the robot 10.

[0040] As in Fig. As shown in Figure 8, assume that an obstacle 250 enters the work area 201. In this case, the entry of the obstacle 250 into the work area 201 is detected by the area monitoring unit. The area setting unit may, for example, set a rectangular area 260 enclosing the obstacle 250 based on the detection result of the obstacle 250 and reset a work area such that the area 260 is excluded from the work area 201. As a result, the area 260 is excluded from the work area in which the robot 10 is allowed to move, and interference between the robot 10 and the obstacle 250 can be avoided. Such reset of a work area can be performed in real time.

[0041] Fig. 9 illustrates a state in which the robot 10 performs a movement to leave the work area. Assume that an arm 11 of the robot 10 leaves the work area 201. The area monitoring unit detects the robot 10 leaving the work area 201 based on an image captured by the visual sensor 71. In this case, the motion control unit can cancel the force control operation by the force control unit and proceed to processing a next operation instruction. As a result, a situation in which the flow of the entire work is interrupted can be avoided.

[0042] Fig. 10 is a flowchart illustrating a flow of processing including the above-described force control mode setting and range setting / monitoring in the robot program 100.

[0043] First, for example, an operator sets the parameters of a tracking plan through a UI screen (step S11). As a result, the tracking plan setting data is created as described above. Next, the operator creates a robot program that includes the force control performed with the tracking operation. The operator assigns the robot program to the tracking plan number.

[0044] Next, the operator instructs the robot controller to execute the robot program created as described above. If force control is executed in the robot program, the determination unit 154 determines whether the robot program is a robot program that includes the tracking operation (step S14). If it is determined that the robot program is a robot program that includes the tracking operation (S14: YES), the force control setting unit 155 sets to the mode of force control executed during a tracking operation (step S15). If it is determined that the robot program is not a robot program that includes the tracking operation (S14: NO), the force control setting unit 155 sets to the regular force control mode (step S16).

[0045] After setting the force control mode in this way, an operation based on the force control is executed in accordance with the robot program (step S17).

[0046] Next, real-time monitoring of a work area is performed by the visual sensor 71 (step S18). The area setting unit 161 determines whether a work area is set (step S19). If a work area has already been set by a user (S19: YES), the processing proceeds to step S21. If no work area is set (S19: NO), the area setting unit 161 automatically sets a work area of ​​the robot 10, as described above with reference to Fig. 7 (step S20).

[0047] The area monitoring unit 162 continues monitoring the work area based on an image captured by the visual sensor 71 (step S12). If the area monitoring unit 162 determines that an obstacle has entered the work area (S22: YES), the area setting unit 161 resets a safe work area so as to exclude the obstacle area, as described with reference to Fig. 8 (step S23).

[0048] Next, the area monitoring unit 162 determines whether the robot 10 is outside the work area (step S24). If it is determined that the robot 10 is outside the work area (S24: YES), the motion control unit 151 cancels the currently executed force control operation (step S25) and executes an instruction for a next work (step S26). On the other hand, if it is determined that the robot 10 is not outside the work area (S24: NO), the motion control unit 151 proceeds to execute an instruction for a next work normally (step S26).

[0049] In this way, according to the present embodiment, it is possible to determine whether a robot program is a robot program that includes the tracking operation and to automatically and appropriately set the force control operation mode. In other words, the present embodiment enables automatic determination of the force control operation mode and automatic setting of the force control.

[0050] Although the present invention has been described above by means of the typical embodiments, it will be apparent to those skilled in the art that changes and various other changes, omissions and additions can be made to the above-mentioned embodiments without departing from the scope of the present invention.

[0051] When arranging the functional blocks in the Fig. The graphical functional block diagram shown in Figure 2 is an example, and various modified examples may exist with respect to the arrangement of functions. For example, the function of the visual data processing device 70 may be provided in the robot controller 50.

[0052] Although the force control operation mode is determined based on a robot program according to the above-mentioned embodiment, whether the force control operation mode is the operation mode for performing force control during a tracking operation or the operation mode for regular force control is determined based on a robot program, the present invention is not limited to such a determination example. The force control operation mode can be determined based on various types of information acquired by a robot program or various types of data associated with the robot program, and the force control operation mode can be automatically changed by changing force control setting parameters according to the determination result.

[0053] The operation panel 20 and the display device 40 may each have a configuration as an ordinary computer including a CPU, a ROM, a RAM, a storage device, an operation unit, a display unit, an input / output interface, a network interface, etc.

[0054] A program that Fig. 3 shown investigation processing and various types of Fig. 10 may be recorded on various computer-readable recording media (such as 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 Arm 20 Control panel 30 hands 40 Display device 50 Robot control device 51 processor 52 storage unit 60 force sensor 70 Device for processing visual data 71 visual sensor 80 stationary sensor 100 robot system 151 Motion control unit 152 Article recognition unit 153 Movement amount detection unit 154 Investigation Unit 155 Force control adjustment unit 156 force control unit 161 Range setting unit 162 Area Monitoring Unit 171 Visual data processing unit 172 storage unit 110 stationary workbench 120 conveyor device 121 pulse encoders 201, 202 Work area 300, 301 Tracking plan 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 2018-171665 A

[0004] JP 2020-189392 A

[0004]

Claims

[1] Robot system comprising: a robot; a robot control device configured to execute a robot program and control the robot; and a force detection unit configured to detect a force acting on the robot, wherein the robot control device includes: a determination unit configured to determine an operating mode of a force control based on the robot program using the force detection unit, wherein the force control is executed in the robot program; and a force control setting unit configured to perform setting of the force control according to the operation mode of the force control determined by the determination unit. [2] The robot system according to claim 1, further comprising a conveyor device, wherein the determination unit determines, based on the robot program, whether the operation mode of the force control is an operation mode for executing force control while tracking an article conveyed on the conveyor device or an operation mode of regular force control executed without tracking an article. [3] The robot system according to claim 2, wherein the determination unit determines whether the force control operation mode is an operation mode that performs force control while tracking an article or an operation mode of regular force control by determining whether the robot program is associated with setting data related to a tracking operation. [4] The robot system according to any one of claims 1 to 3, wherein the force control setting unit automatically sets a force control parameter according to the determined operation mode of the force control. [5] The robot system according to any one of claims 1 to 4, further comprising a visual sensor, wherein the robot control device further includes an area setting unit configured to perform setting in connection with a work area of ​​the robot as a monitoring target by the visual sensor. [6] The robot system according to claim 5, wherein, when the work area is not set, the area setting unit sets the work area in an image pickup area of ​​the visual sensor based on position information of the visual sensor and the robot. [7] Robot system according to claim 5, wherein the robot control device further includes an area monitoring unit configured to detect an entry of an obstacle into the work area based on an image captured by the visual sensor, and the area setting unit readjusts the working area so that an area in which the obstacle is located in the working area is excluded from the working area. [8] The robot system according to claim 5, wherein the robot control device further includes an area monitoring unit configured to perform control to cancel the force control when the robot is outside the work area. [9] Robot control device for executing a robot program and controlling a robot, the robot control device comprising: a determination unit configured to determine, based on the robot program, an operating mode of a force control using a force detection unit, wherein the force control is executed in the robot program; and a force control setting unit configured to perform setting of the force control according to the operation mode of the force control determined by the determination unit. [10] The robot control device according to claim 9, wherein the determination unit determines, based on the robot program, whether the operation mode of the force control is an operation mode for executing force control while tracking an article conveyed on a conveyor or an operation mode of regular force control executed without tracking an article. [11] The robot control device according to claim 10, wherein the determination unit determines whether the force control operation mode is an operation mode that performs force control while tracking an article or an operation mode of regular force control by determining whether the robot program is associated with setting data related to a tracking operation. [12] The robot control device according to any one of claims 9 to 11, wherein the force control setting unit automatically sets a force control parameter according to the determined operation mode of the force control. [13] The robot control device according to any one of claims 9 to 12, further comprising an area setting unit configured to perform setting in connection with a working area of ​​the robot as a monitoring target by a visual sensor. [14] The robot control device according to claim 13, wherein, when the work area is not set, the area setting unit sets the work area in an image pickup area of ​​the visual sensor based on position information of the visual sensor and the robot. [15] Robot control device according to claim 13, further comprising an area monitoring unit configured to detect an entry of an obstacle into the work area based on an image captured by the visual sensor, wherein the area setting unit readjusts the working area so that an area in which the obstacle is located in the working area is excluded from the working area. [16] The robot control device according to claim 13, further comprising an area monitoring unit configured to perform control to cancel the force control when the robot is outside the work area.

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