Robot system and robot control device

Abstract

A robot system (100) is provided with: 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) being provided with: a determination unit (154) that determines, on the basis of the robot program, an operation pattern of force control executed in the robot program using the force detection unit; and a force control setting unit (155) that sets the operation of the force control on the basis of the operation pattern of the force control determined by the determination unit.

Description

Technical Field

[0001] The present invention relates to a robot system and a robot control device. Background Art

[0002] A robot system is known in which a robot is configured to perform a predetermined operation on an article being transported on a transport device while tracking the article.

[0003] Patent document 1 describes a robot system including a robot 100, an end effector 200, a robot control device 300, a camera 400, and a conveying device 500 (paragraph 0033). In addition, Patent document 1 describes that "the control signal generating unit 310 generates a position control signal indicating a target position where the end effector 200 should be located, and outputs the signal to the position control unit 320. When the control signal generating unit 310 receives an instruction from the user that tracking control should be performed, the control signal generating unit 310 outputs a signal to perform tracking control to the position control unit 320. When the control signal generating unit 310 receives an instruction from the user that force control should be performed, the control signal generating unit 310 outputs a control signal to perform force control to the position control unit 320" (paragraph 0042).

[0004] Patent Document 2 discloses a control method for a robot 1 that uses an end effector 20 to perform an operation on an object W carried by a carrying device 50. The method includes calculating a target position of the end effector 20 based on the position of the object W, calculating a tracking correction amount for correcting the target position in a manner corresponding to the amount of the object W to be carried, causing the end effector 20 to follow the object W based on the target position and the tracking correction amount, obtaining a force acting from the object W on the end effector 20 using a force sensor P, calculating a force control correction amount for correcting the target position in a manner that makes the force become a target force, and driving the robot 10 based on the force control correction amount, thereby controlling the force to be a predetermined target force. (Abstract)

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-171665

[0008] Patent Document 2: Japanese Patent Application Publication No. 2020-189392 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] When a robot program is generated that uses force control to perform operations during tracking, it is necessary to add a notification command for the action mode of the force control before and after the command that calls the force control command. This may also become a major cause of human errors such as setting errors. A robot system and a robot control device that can automate the setting of the action mode of the force control are desired.

[0011] Means for solving problems

[0012] One embodiment of the present disclosure is a robot system comprising: a robot; a robot control device that executes a robot program to control the robot; and a force detection unit that detects the force acting on the robot, the robot control device comprising: a determination unit that determines, based on the robot program, an action mode of force control using the force detection unit executed in the robot program; and a force control setting unit that performs action settings for the force control according to the action mode of the force control determined by the determination unit.

[0013] Another embodiment of the present disclosure is a robot control device that executes a robot program to control a robot, the robot control device comprising: a determination unit that determines, based on the robot program, an action mode of force control using a force detection unit executed in the robot program; and a force control setting unit that performs action settings for the force control according to the action mode of the force control determined by the determination unit.

[0014] Effects of the Invention

[0015] According to the above configuration, the operation mode of the force control can be automatically determined, and the operation setting of the force control can be automatically performed.

[0016] These and other objects, features and advantages of the present invention will become more apparent from the detailed description of typical embodiments of the present invention as shown in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing the device configuration of a robot system according to an embodiment.

[0018] Figure 2 It is the functional structure diagram of the robot system.

[0019] Figure 3 This is a flowchart showing the process of determining the operation mode of the force control.

[0020] Figure 4 This is a conceptual diagram showing the relationship between the robot program and the tracking schedule.

[0021] Figure 5This is an example of a confirmation screen for the association between the robot program and the tracking schedule.

[0022] Figure 6 It is a diagram for explaining a setting example of a work area.

[0023] Figure 7 It is a diagram showing an example of automatically setting a work area.

[0024] Figure 8 This is a diagram for explaining an example of resetting the work amount meter by removing an obstacle.

[0025] Fig. 9 This is a diagram for explaining a state in which it is detected that the robot has left the work area.

[0026] Fig.10 This is a flowchart showing a series of processes including contents related to setting of the force control mode to setting / monitoring of the area. DETAILED DESCRIPTION

[0027] Next, the embodiments of the present disclosure are described with reference to the accompanying drawings. In the referenced drawings, the same structural parts or functional parts are marked with the same reference symbols. For easy understanding, the scales of these drawings are appropriately changed. In addition, the method shown in the drawings is an example for implementing the present invention, and the present invention is not limited to the method shown in the drawings.

[0028] Figure 1 FIG. 1 is a diagram showing the device configuration of a robot system 100 according to one embodiment. Figure 1 As shown, the robot system 100 includes a conveying device 120 for conveying a workpiece, a robot 10, a robot control device 50 for controlling the robot 10, a visual sensor 71, and a visual data processing device 70 for controlling the visual sensor 71. The visual data processing device 70 is connected to the robot control device 50. The conveying device 120 includes a pulse encoder 121 as a sensor for detecting the amount of movement of the workpiece by the conveying device 120. The visual sensor 71 is, for example, fixed to the working space and has functions such as monitoring the working area. A fixed sensor 80 for detecting the workpiece is arranged on the conveying device 120. The fixed sensor 80 may, for example, be a sensor that includes a light emitting portion and a light receiving portion and detects an object passing between the light emitting portion and the light receiving portion. In addition, Figure 1 In the figure, some of the elements constituting the robot system 100 (operation panel 20, display device 40 (see Figure 2 )).

[0029] The robot 10 can perform the desired work by means of an end effector mounted on the wrist at the front end of the arm. The end effector is an external device that can be replaced according to the purpose, such as a manipulator, welding gun, tool, etc. Figure 1, an example using a robot 30 as an example of an end effector is shown.

[0030] In the robot 10, a force sensor 60 is arranged as a force detection unit for detecting a force (external force) acting on the robot 10 between the manipulator 30 as a working tool and the front end portion (flange) of the arm. The force sensor 60 is, for example, a six-axis force sensor that detects forces in three axial directions of the X-axis, Y-axis, and Z-axis acting on the working tool and moments around the X-axis, Y-axis, and Z-axis. That is, the force sensor 60 is capable of detecting the force / torque generated by the contact between the component supported by the robot 10 or the working tool and an object. In order to detect the force acting on the robot 10, other force detectors (for example, torque sensors arranged on each axis of the robot) may also be used.

[0031] In the robot system 100, the robot 10 can perform a predetermined task by applying force control while tracking the workpieces flowing on the transport device 120. Figure 1 , an example of performing a task of fitting a workpiece W1 as a component held by the robot 10 into a hole of a workpiece W flowing on the transport device 120 is shown.

[0032] In addition, a fixed work table 110 is disposed on the robot system 100. The robot 10 (robot control device 50) can also perform work in a normal force control mode on a workpiece disposed on the fixed work table.

[0033] The robot system 100 of the present embodiment is configured to automatically determine whether the force control mode during tracking or the normal force control mode should be applied based on the robot program, and to perform force control mode setting.

[0034] Figure 2 1 is a functional block diagram of the robot system 100. The robot control device 50 may have a general computer structure including a processor 51, a storage unit (memory) 52, and various input / output interfaces and an operation unit (not shown) as hardware components. Figure 2 FIG. 5 illustrates the functional blocks implemented by the processor 51 executing the software. Figure 2 As shown, the robot control device 50 includes a motion control unit 151 , an article detection unit 152 , a movement amount detection unit 153 , a determination unit 154 , a force control setting unit 155 , and a force control unit 156 .

[0035] The storage unit 52 stores a robot program for causing the robot 10 to execute a predetermined task and a tracking schedule 300 including setting information related to tracking that is applied when causing the robot 10 to perform a task by following a workpiece flowing on the transport device 120 .

[0036] The robot programs registered in the storage unit 52 include a robot program A for performing a predetermined operation using force control while causing the robot 10 to track, and a robot program B for performing a predetermined operation using force control on the fixed work table 110 without tracking.

[0037] The motion control unit 151 controls the motion of the robot 10 according to the robot program. The article detection unit 152 can detect the timing of the workpiece transported in the transport device 120 entering the working area based on the signal from the fixed sensor 80, for example. The movement amount detection unit 153 can obtain the movement amount of the robot 10 during tracking based on the signal from the pulse encoder 121. In addition, as a method for detecting the movement amount of the workpiece transported on the transport device 120, in addition to using the signal from the pulse encoder 121, a method of detecting the movement amount of the workpiece by a visual sensor can also be used. For example, a method of obtaining the movement amount of the workpiece by capturing the movement of the workpiece being transported using a camera mounted on the front end of the hand of the robot 10 can also be used.

[0038] The motion control unit 151 can perform predetermined operations on the workpiece by applying force control while following the workpiece flowing on the conveying device 120 based on the detection timing of the workpiece by the article detection unit 152 and information about the movement amount of the workpiece obtained by the movement amount detection unit 153.

[0039] The determination unit 154 automatically determines, based on the robot program to be executed, whether the robot program is in an operation mode in which force control is performed while tracking or in an operation mode in which normal force control is performed.

[0040] The force control setting unit 155 switches the action mode of the force control between the force control mode during tracking and the normal force control mode according to the determination result of the determination unit 154. In the force control during tracking, the workpiece W1 contacts the workpiece W during the action of the robot 10 fitting the workpiece W1 with the workpiece W, so it is considered that the action of the robot 10 vibrating is likely to occur. In view of this, the force control during tracking includes, as an example, setting parameters related to filtering for reducing the vibration of the robot 10. In this way, the force control setting unit 155 sets different force control parameters in the normal force control mode and the force control during tracking.

[0041] The force control unit 156 performs force control using the force sensor 60 according to the force control parameters set by the force control setting unit 155 .

[0042] The visual data processing device 70 may also have a computer structure including a processor, a memory, etc. Figure 2As shown, the visual data processing device 70 includes a visual data processing unit 171 and a storage unit 172. The visual data processing unit 171 can provide a function of performing various image processing for detecting and monitoring an object based on an image captured by the visual sensor 71. For example, the visual data processing unit 171 can provide a function of detecting an object in an image based on model data of the object. It is also possible to use the workpiece W detection function of the visual sensor 71 (visual data processing device 70) to control the position of the robot 10 when the robot 10 operates on the workpiece W.

[0043] The storage unit 172 stores calibration data of the visual sensor 71 and various setting information required for executing image processing.

[0044] like Figure 2 As shown, the robot control device 50 may be connected to an operation panel 20 for inputting commands to the robot control device 50 and outputting various information. In addition, the robot control device 50 may be connected to a display device 40 for displaying various information related to the work performed by the robot 10.

[0045] The structure for determining whether the force control during tracking or the normal force control is determined by the determination unit 154 is described. When a robot program is configured to operate the transport device 120 and cause the robot to perform tracking, setting data (referred to as a tracking schedule) including various setting information related to tracking is prepared. For example, the operator can input setting parameters of the tracking schedule via a UI (user interface) screen. Such a UI screen can also be displayed on the display unit of the operation panel 20. The parameters of the tracking schedule can include, for example, the following.

[0046] Tracking timesheet numbers

[0047] Tracking Type

[0048] Tracking reference coordinate system

[0049] Tracking direction

[0050] Encoder for tracking

[0051] Encoder scale factor

[0052] "Tracking schedule number" indicates the number of the tracking schedule data. When multiple tracking schedules are prepared, they can be identified separately by this number. "Tracking type" is used when specifying the type by the tracking action (for example, a linear action, an arc-shaped action, etc.). "Reference coordinate system for tracking" specifies the coordinate system used as a reference when tracking the action of the object. "Tracking direction" specifies the direction in which tracking is performed. "Encoder for tracking" specifies the identification number of the encoder that serves as a movement detector for tracking. "Encoder scale factor" specifies the relationship between the encoder's pulse count and the moving distance of the conveying device.

[0053] A robot program that causes a robot to perform a tracking-based task is accompanied by a reference to such a tracking schedule. Figure 4 , a robot program 501 for causing a robot to perform a task based on tracking is shown as a conceptual diagram to refer to a tracking schedule 301. The reference to the tracking schedule 301 by the robot program 501 may be, for example, a program instruction (a definition statement that takes in the tracking schedule data as a variable) for enabling the robot program 501 to refer to the data of the tracking schedule 301.

[0054] In this way, the robot program 501 with tracking is associated with the tracking schedule 301. The determination unit 154 determines whether the motion mode of force control of the robot program is the motion mode of force control with tracking or the motion mode of normal force control, based on whether the robot program is associated with the tracking schedule.

[0055] Figure 5 This shows an example of a screen in which the robot program associated with tracking and the tracking schedule are confirmed to be associated. Figure 5 The left screen 351 is an example of a screen showing a program to be confirmed. Here, the name of the program to be confirmed is "TTESTSUB". Figure 5 In the right screen 352 in FIG. 1 , the tracking schedule numbered “1” (see the display column of reference numeral 361 ) is displayed, which is referenced by the program “TTESTSUB”.

[0056] Figure 31 is a flowchart showing the discrimination process of the action mode of force control in the robot control device 50. First, as described above, the discrimination unit 154 determines whether the robot program is a robot program accompanied by tracking based on whether the robot program is associated with the tracking schedule (step S1). When it is determined that the robot program is not a robot program accompanied by tracking (S1: No), the force control setting unit 155 sets the force control parameters for performing normal force control to the force control unit 156, thereby automatically setting it to the normal force control mode (step S2). When it is determined that the robot program is a robot program accompanied by tracking (S1: Yes), the force control setting unit 155 sets the force control parameters for performing force control during tracking to the force control unit 156, thereby automatically setting it to the force control mode during tracking (step S3).

[0057] Next, the setting and monitoring functions of the robot control device 50 for the working area of ​​the robot 10 will be described. Figure 2 As shown, the robot control device 50 includes an area setting unit 161 and an area monitoring unit 162 .

[0058] The area setting unit 161 provides a function for setting the area in which the robot 10 operates. As an example, the area setting unit 161 may be configured to accept setting input for setting the operating area via a UI (user interface) screen. Here, the operating area may also 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 operating area may also be defined as an area extending two-dimensionally on the conveying surface of the conveying device 120.

[0059] The area monitoring unit 162 monitors the working area based on the image captured by the visual sensor 71, and detects the intrusion of obstacles into the working area and the departure of the robot 10 from the working area. The area monitoring unit 162 can provide a monitoring function using the image processing function of the visual data processing unit 171. As an example, the area monitoring unit 162 can also detect the entry of an object into the working area and the departure of the robot 10 from the working area by comparing the pixel values ​​of the continuous images captured by the visual sensor 71. Other object detection methods known in the art for detecting objects in an image can also be used.

[0060] Figure 6 A schematic diagram showing a state in which a work area 201 of the robot 10 is set on the transport device 120. The robot 10 can also perform predetermined operations based on force control while tracking the workpiece W3 flowing on the transport device 120, and can also perform normal force control operations on the workpiece through the fixed workbench 110.

[0061] A work area 201 is set on the transport device 120 in front of the robot 10. The vision sensor 71 is arranged so as to be able to capture an image of a range including the work area 201. The area monitoring unit 162 monitors the work area based on the image captured by the vision sensor 71.

[0062] In addition, when the work area is not set, the area setting unit 161 may automatically set the work area within the imaging range of the visual sensor 71 based on the position information of the visual sensor 71 and the robot 10. For example, as an area extending two-dimensionally in front of the robot 10 and on the transport device 120, the area setting unit 161 may automatically set the work area. Figure 7 A working area 202 is shown.

[0063] like Figure 8 As shown, it is assumed that the obstacle 250 enters the working area 201. In this case, the area monitoring unit detects the entry of the obstacle 250 into the working area 201. The area setting unit can set the area 260 of the processing rectangle of the obstacle 250 based on the detection result of the obstacle 250, for example, and re-set the working area in a manner of excluding the area 260 from the working area 201. In this way, the area 260 is excluded from the working area where the robot 10 can move, and the interference between the robot 10 and the obstacle 250 can be avoided. Such re-setting of the working area can also be performed in real time.

[0064] Fig. 9 Indicates the situation where the robot 10 has performed an action to leave the working area. Here, the arm 11 of the robot 10 has left the working area 201. The area monitoring unit detects the robot 10 leaving the working area 201 based on the image from the visual sensor 71. In this case, the motion control unit can also interrupt the force control action of the force control unit and transfer to the next motion command. In this way, it is possible to avoid the situation where the entire process of the operation is stopped.

[0065] Fig.10 This is a flowchart showing a series of processes in the robot system 100 including contents related to the setting of the force control mode described above to the setting / monitoring of the area.

[0066] First, for example, the operator sets the parameters of the tracking schedule via the UI screen (step S11). Thus, the setting data of the tracking schedule as described above is prepared. Next, the operator creates a robot program with force control based on tracking. At this time, the operator associates the number of the tracking schedule with the robot program.

[0067] Next, the operator executes the robot program generated as described above. When the force control is executed in the robot program, the determination unit 154 determines whether the robot program is a robot program accompanied by tracking (step S14). When it is determined that it is a robot program accompanied by tracking (S14: Yes), the force control setting unit 155 sets the force control mode to the tracking mode (step S15). When it is determined that it is not a robot program accompanied by tracking (S14: No), the force control setting unit 155 sets the force control mode to the normal mode (step S16).

[0068] After the force control mode is set in this way, the operation based on the force control is executed according to the robot program (step S17).

[0069] Next, the visual sensor 71 monitors the working area in real time (step S18). The area setting unit 161 determines whether a working area has been set (step S19). If the working area has been set by the user (S19: Yes), the process proceeds to step S21. If the working area has not been set (S19: No), refer to Figure 7 As described above, the area setting unit 161 automatically sets the working area of ​​the robot 10 (step S20).

[0070] The area monitoring unit 162 continues to monitor the work area based on the image from the visual sensor 71 (step S12). When the area monitoring unit 162 determines that there is an obstacle in the work area (S22: Yes), it refers to Figure 8 As shown, the area setting unit 161 re-sets the safe work area to exclude the area of ​​obstacles (step S23).

[0071] Next, the area monitoring unit 162 determines whether the robot 10 has left the work area (step S24). If it is determined that the robot 10 has left the work area (S24: Yes), the motion control unit 151 interrupts the force control operation being executed (step S25) and executes the execution command of the next operation (step S26). On the other hand, if it is determined that the robot 10 has not left the work area (S24: No), the motion control unit 151 advances the execution of the execution command of the next operation as usual (step S26).

[0072] Thus, according to this embodiment, it is possible to automatically and appropriately set the action mode of force control by determining whether the robot program is a robot program with tracking. That is, according to this embodiment, it is possible to automatically determine the action mode of force control and automatically perform the action setting of force control.

[0073] Although the present invention has been described above using typical embodiments, it will be understood by those skilled in the art that changes to the above-described embodiments and various other changes, omissions, and additions may be made without departing from the scope of the present invention.

[0074] Figure 2 The allocation of the functional blocks in the functional block diagram is an example, and various modifications are possible regarding the functional allocation. For example, the function of the visual data processing device 70 may be mounted in the robot control device 50 .

[0075] The above-mentioned embodiment is a structure in which whether the action mode of force control is the action mode of force control in tracking or the action mode of normal force control is determined based on the robot program, but the present invention is not limited to such an example of determination. The action mode of force control can be determined based on various information obtained from the robot program or various data associated therewith, and the setting parameters of force control can be changed according to the determination result to automatically change the action mode of force control.

[0076] Furthermore, the operation panel 20 and the display device 40 may have a configuration as a general computer including a CPU, a ROM, a RAM, a storage device, an operation unit, a display unit, an input / output interface, a network interface, and the like.

[0077] implement Figure 3 The determination process shown, Fig.10 The programs of the various processes shown can be recorded in various computer-readable recording media (for example, semiconductor memories such as ROM, EEPROM, and flash memory, magnetic recording media, and optical disks such as CD-ROM and DVD-ROM).

[0078] Explanation of symbols

[0079] 10. Robot

[0080] 11 arms

[0081] 20 Operation panel

[0082] 30 Robot

[0083] 40 Display device

[0084] 50Robot control device

[0085] 51 processors

[0086] 52 Storage

[0087] 60 Force Sensor

[0088] 70 Visual data processing device

[0089] 71 Vision Sensor

[0090] 80 fixed sensors

[0091] 100 Robotic Systems

[0092] 151 Motion Control Unit

[0093] 152 Article Inspection Department

[0094] 153 Movement amount detection unit

[0095] 154 Identification Department

[0096] 155 force control setting unit

[0097] 156 Force Control Department

[0098] 161 Area Setting Department

[0099] 162 Regional Monitoring Department

[0100] 171 Visual Data Processing Department

[0101] 172 Storage Department

[0102] 110 Fixed workbench

[0103] 120 handling device

[0104] 121 pulse encoder

[0105] 201, 202 work area

[0106] 300, 301 tracking timeline.

Claims

1. A robot system, characterized in that: have: robot; a robot control device that executes a robot program to control the robot; and a force detection unit for detecting a force acting on the robot, The robot control device comprises: a determination unit that determines, based on the robot program, an operation mode of force control using the force detection unit executed in the robot program; as well as A force control setting unit performs operation 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, characterized in that: The robot system further comprises a transport device. The determination unit determines, based on the robot program, whether the force control operation mode is an operation mode in which force control is performed while tracking an article being transported on the transport device or a normal force control operation mode without tracking.

3. The robot system according to claim 2, characterized in that: The determination unit determines whether the operation mode of the force control is an operation mode of executing force control while tracking or a normal operation mode of force control by determining whether the robot program is associated with setting data regarding tracking.

4. The robot system according to any one of claims 1 to 3, characterized in that: 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, characterized in that: The robot system also has a visual sensor. The robot control device further includes an area setting unit for setting a working area of ​​the robot to be monitored by the visual sensor.

6. The robot system according to claim 5, characterized in that: When the work area is not set, the area setting unit sets the work area within an imaging range of the vision sensor based on position information of the vision sensor and the robot.

7. The robot system according to claim 5, characterized in that: The robot control device further includes: an area monitoring unit that detects that an obstacle has entered the work area based on the image captured by the visual sensor, The area setting unit resets the work area so that an area in the work area where the obstacle exists is outside the work area.

8. The robot system according to claim 5, characterized in that: The robot control device further includes an area monitoring unit configured to perform control to interrupt the force control when the robot moves out of the work area.

9. A robot control device that executes a robot program to control a robot, characterized in that: The robot control device comprises: a determination unit that determines, based on the robot program, an operation mode of force control using a force detection unit executed in the robot program; as well as A force control setting unit performs operation 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, characterized in that: The determination unit determines, based on the robot program, whether the force control operation mode is an operation mode in which force control is performed while tracking an article being transported on a transport device or a normal force control operation mode without tracking.

11. The robot control device according to claim 10, characterized in that: The determination unit determines whether the operation mode of the force control is an operation mode of executing force control while tracking or a normal operation mode of force control by determining whether the robot program is associated with setting data regarding tracking.

12. The robot control device according to claim 9, characterized in that: 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, characterized in that: The robot control device further includes an area setting unit for setting a working area of ​​the robot to be monitored by the visual sensor.

14. The robot control device according to claim 13, characterized in that: When the work area is not set, the area setting unit sets the work area within an imaging range of the vision sensor based on position information of the vision sensor and the robot.

15. The robot control device according to claim 13, characterized in that: The robot control device further includes: an area monitoring unit that detects a situation where an obstacle enters the working area based on the image captured by the visual sensor. The area setting unit resets the work area so that an area in the work area where the obstacle exists is outside the work area.

16. The robot control device according to claim 13, characterized in that: The robot control device further includes an area monitoring unit configured to perform control to interrupt the force control when the robot moves out of the work area.

Images