Robot control system, robot control method, and program

Abstract

To control a robot without performing complicated calculation.SOLUTION: A robot control system 1 includes a first robot 10 to which a tool T is attached, and a second robot 20 capable of changing a relative posture of the tool T with respect to a workpiece W. A determination unit that determines whether the posture of the first robot 10 is in a posture change limit neighboring region that is a region close to a limit of a change range of the posture of the first robot 10 or in a posture change limit remote region that is a region farther from the limit than the posture change limit neighboring region, and a control unit that controls the first robot 10 and the second robot 20 to change the relative posture based on a determination result of the determination unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a robot control system, a robot control method, and a program. [Background technology]

[0002] 2. Description of the Related Art Conventionally, robots equipped with tools have been used to perform operations such as machining on workpieces. Patent Documents 1 and 2 disclose technologies relating to the cooperative operation of a dual-arm robot arm control device. Patent Documents 1 and 2 disclose a control system in a robot system consisting of two robot arms, in which the position and attitude of one robot arm is cooperatively controlled by manipulating the other robot arm. In Patent Documents 1 and 2, the dynamic manipulability ellipsoid is calculated when cooperatively controlling the robot arms. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 4-2577 [Patent Document 2] Japanese Utility Model Application Publication No. 4-2578 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the calculation of the dynamic manipulability ellipsoid performed in Patent Documents 1 and 2 is complicated.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to control a robot without performing complicated calculations. [Means for solving the problem]

[0006] A robot control system according to one embodiment of the present disclosure is a robot control system comprising a first robot to which a tool is attached and a second robot capable of changing the relative attitude of the tool with respect to a workpiece, characterized in that the system comprises a determination means for determining whether the attitude of the first robot is in an attitude change limit near area, which is an area close to the limit of the change range of the attitude of the first robot, or in an attitude change limit far area, which is an area farther from the limit than the attitude change limit near area, and a control means for controlling the first robot and the second robot to change the relative attitude based on the determination result of the determination means. [Effects of the Invention]

[0007] According to the present disclosure, a robot can be controlled without performing complicated calculations. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a robot control system according to an embodiment. [Figure 2] FIG. 10 is a diagram showing a state in which the end plate of the first robot is in an initial position. [Figure 3] FIG. 10 is a diagram showing a state in which the arm of the first robot is extended and the end plate is separated from the base. [Figure 4] FIG. 2 is a schematic block diagram showing a specific example of the functional configuration of a control device provided in the robot control system. [Figure 5] 10 is a first example of the relationship between the distance between the center point of the end plate of the first robot and the rotation center point of the first robot, and the size of the posture change limit remote region. [Figure 6] 10 is a second example of the relationship between the distance between the center point of the end plate of the first robot and the rotation center point of the first robot, and the size of the posture change limit remote region. [Figure 7] FIG. 2 is a diagram showing a state in which the first robot is at an initial position in the first embodiment. [Figure 8]FIG. 2 is a diagram showing a state in which the first robot is in a posture change limit remote area in the first embodiment. [Figure 9] FIG. 10 is a diagram showing a case in which the first robot is in a region near the posture change limit and the second robot operates in the first control mode in the first embodiment. [Figure 10] FIG. 10 is a diagram showing a case where the second robot operates in the second control mode in the first embodiment. [Figure 11] 1 is a flowchart of a robot control method according to an embodiment. [Figure 12] FIG. 1 is a diagram illustrating an outline of a hardware configuration example of an information processing apparatus applied to an embodiment. [Figure 13] FIG. 10 is a diagram showing a state in which the first robot is at an initial position in the second embodiment. [Figure 14] FIG. 11 is a diagram showing a state in which the first robot is in a posture change limit remote area in the second embodiment. [Figure 15] FIG. 10 is a diagram showing a case in which the second robot operates in the first control mode while the first robot is in a region near the posture change limit in the second embodiment. [Figure 16] FIG. 10 is a diagram showing a case where the second robot operates in the second control mode in the second embodiment. [Figure 17] This is a modified example of the workpiece W. DETAILED DESCRIPTION OF THE INVENTION

[0009] A robot control system, a robot control method, and a program according to an embodiment of the present disclosure will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a robot control system 1 according to an embodiment. As shown in FIG. 1, the robot control system 1 includes a first robot 10, a second robot 20, and a control device 30. The first robot 10, the second robot 20, and the control device 30 are communicably connected to each other via a network N. The network N may be a network using wireless communication or a network using wired communication. The network N may be configured using, for example, the Internet or a local area network (LAN). The network N may also be configured by combining multiple networks.

[0010] The robot control system 1 changes the relative posture between the tool T and the workpiece W using the first robot 10 and the second robot 20. In this embodiment, changing the relative posture between the tool T and the workpiece W means changing the relative position or relative angle between the tool T and the workpiece W. In this embodiment, the relative orientation of the tool T with respect to the workpiece W includes a first relative orientation and a second relative orientation. The first relative orientation is, among the relative orientations of the tool T with respect to the workpiece W, the relative orientation around the first axis Sf1 of the first robot 10. The second relative orientation is, among the relative orientations of the tool T with respect to the workpiece W, the relative orientation around the second axis Sf2 of the first robot 10. In this embodiment, the first axis Sf1 of the first robot 10 is an axis that extends in any horizontal direction with the center point 13a of the end plate 13 as a reference when the first robot 10 is in a neutral posture, i.e., when an end plate 13 (described later) is in its initial position, and when the second robot 20 is in a neutral posture, i.e., when an arm 21 (described later) is in its initial position. The second axis Sf2 of the first robot 10 is an axis that extends in a horizontal direction perpendicular to the first axis Sf1 with the center point 13a of the end plate 13 as a reference when the first robot 10 and the second robot 20 are in their neutral postures. In this embodiment, the coordinates of the end plate 13 of the first robot 10 and the tool T may be managed based on an absolute coordinate system including the first axis Sf1 and second axis Sf2 described above. The absolute coordinate system may be stored, for example, in a storage unit 34 of the control device 30, which will be described later. Furthermore, the position of each robot, the length and inclination between two objects, and the like, which will be described below, may be recognized by the control device 30 based on the absolute coordinate system.

[0011] In this embodiment, changing the relative posture of the tool T and the workpiece W may mean moving only the tool T with respect to the stationary workpiece W, or may mean moving both the tool T and the workpiece W. In this way, the robot control system 1 changes the relative posture of the tool T with respect to the workpiece W. In this way, the robot control system 1 contributes to making it easier to perform work on the workpiece W using the tool T. Hereinafter, in this embodiment, moving the tool T and the workpiece W relative to each other means moving only the tool T relative to the stationary workpiece W. However, as shown in a second embodiment described later, the workpiece W may be moved to move the tool T and the workpiece W relative to each other.

[0012] In this embodiment, the tool T is, for example, a polishing tool such as a grindstone or a buff. Alternatively, the tool T may be a tool such as a drill or a screwdriver, a painting tool such as a paintbrush or a brush, or any other device. The workpiece W may be an object on which any operation is performed by such a tool T. In this embodiment, the workpiece W has a convex shape with a raised center, for example, as shown in FIG.

[0013] As shown in FIG. 1, a tool T is attached to a first robot 10. The first robot 10 moves the tool T toward or away from a workpiece W. The first robot 10 is, for example, a parallel link robot. In this embodiment, the first robot 10 is a parallel link robot (hexa robot) with six degrees of freedom. As shown in FIG. 1 , the first robot 10 includes a base unit 11, an arm unit 12, and an end plate 13. The base unit 11 is a portion to which each component of the first robot 10 is attached. A configuration for holding the first robot 10 may be attached to the base unit 11. Specifically, for example, a second robot 20 may be attached to the base unit 11. In this manner, the first robot 10 may be movable by the second robot 20. The base unit 11 may also be attached to a support column, a wall, or the like. In this manner, the position of the first robot 10 may be fixed, and only the end plate 13 may be movable. In this embodiment, the second robot 20 is attached to the base unit 11. In other words, in this embodiment, the first robot 10 is movable by the second robot 20. 1, the arm unit 12 is disposed between the base unit 11 and the end plate 13 and supports the end plate 13. Specifically, one end of the arm unit 12 is swingably connected to the end plate 13, and the other end of the arm unit 12 is swingably connected to the base unit 11. In this way, the base unit 11 and the end plate 13 are connected by the arm unit 12, and the end plate 13 is supported by the arm unit 12. A plurality of arm units 12 are provided in the first robot 10. Specifically, the arm units 12 are provided, for example, at three locations at 120° intervals in the circumferential direction of the end plate 13. As shown in FIG. 1 , the arm unit 12 includes a first arm 12a and a second arm 12b. The first arm 12a and the second arm 12b are connected to each other so as to be able to swing. The first arm 12a is located on the end plate 13 side and is connected to the end plate 13. The second arm 12b is located on the base unit 11 side and is connected to the base unit 11. Each of the multiple second arms 12b swings from its end on the base unit 11 side by a servo motor (not shown) or the like provided on the base unit 11. The swing of the second arm 12b causes the first arm 12a and the second arm 12b to swing relative to each other. This causes the arm unit 12 in the first robot 10 to extend and retract. This allows the arm unit 12 to change the posture of the end plate 13. 1, the end plate 13 is a portion of the first robot 10 to which a tool T is attached. The tool T may be attached, for example, at a position corresponding to a center point 13a of the end plate 13. The center point 13a of the end plate 13 may be the center of the end plate 13 in the radial and thickness directions. The tool T, which is attached to a position corresponding to the center point 13a of the end plate 13, changes its posture as the posture of the end plate 13 is changed by the arm unit 12. This allows the first robot 10 to change the posture of the tool T relative to the workpiece W. In addition, a force sensor may be provided at a position corresponding to the center point 13a of the end plate 13 to detect, for example, a reaction force generated when the tool T comes into contact with the workpiece W.

[0014] FIG. 2 is a diagram showing a state in which the end plate 13 of the first robot 10 is in the initial position. FIG. 3 is a diagram showing a state in which the arm unit 12 of the first robot 10 is extended and the end plate 13 is separated from the base unit 11. As shown in FIG. As described above, the first robot 10 is a parallel link robot. In this embodiment, the rotation center C of the tool T when the posture of the tool T changes, as shown in FIG. 2 or 3, is referred to as the rotation center C of the parallel link robot or the rotation center C of the first robot 10. In this embodiment, the tool T rotates around a linear axis passing through the rotation center C of the first robot 10. The linear axis passing through the rotation center C may be parallel to the first axis Sf1 or may be parallel to the second axis Sf2. The position of the rotation center C may be stored in the memory unit 34 of the control device 30. In this embodiment, the range of motion of the tool T, whose posture is changed by the first robot 10, depends on the range of change in the posture of the first robot 10. In this embodiment, the posture of the first robot 10 refers to the current position of the end plate 13 and the current relative angle of the end plate 13 with respect to the first axis Sf1 and the second axis Sf2 in an absolute coordinate system that includes the first axis Sf1 and the second axis Sf2 and has the initial position of the center point 13a as its origin.

[0015] In this embodiment, as shown in Fig. 2 or 3, an area close to the limit of the range of change in the posture of the first robot 10 is referred to as the posture change limit nearby area A1. An area farther from the limit of the range of change in the posture of the first robot 10 than the posture change limit nearby area A1 is referred to as the posture change limit remote area A2. In this embodiment, the posture change limit nearby area A1 and the posture change limit remote area A2 are virtual areas around the first robot 10. In other words, the posture change limit remote area A2 is closer to the standard state of the first robot 10 than the posture change limit nearby area A1. In this embodiment, the posture change limit vicinity region A1 refers to, for example, a region located at a 10% rate from the limit of the trajectory in which the posture, including the position and angle of the end plate 13 of the first robot 10, changes from the initial position to the limit of the movable range. The posture change limit vicinity region A1 may be, for example, a region located at a 20% rate from the limit, or a region located at any rate between 10% and 20% from the limit. Note that the rate of the posture change limit vicinity region A1 may be changed as appropriate during operation of the first robot 10.

[0016] Due to the performance of the first robot 10, which is a parallel link robot, the movable range of the posture of the tool T becomes narrower as the distance between the initial position of the center point 13a of the end plate 13 of the first robot 10 and the rotation center point C of the parallel link robot increases. Specifically, as shown in FIGS. 2 and 3, for example, when the distance between the initial position of the center point 13a and the rotation center point C increases, the arm unit 12 of the first robot 10 is extended from its initial position, causing the tip of the tool T to approach the rotation center point C. This reduces the margin for swinging the second arm 12b by a servo motor (not shown) to change the posture of the end plate 13. This narrows the movable range of the end plate 13. Accordingly, in this embodiment, the posture change limit remote region A2 may be defined to be narrower as the distance between the initial position of the center point 13a of the end plate 13 of the first robot 10 and the rotation center point C of the parallel link robot increases. In other words, as the distance between the initial position of the center point 13a of the end plate 13 and the rotation center point C of the parallel link robot increases, the boundary between the posture change limit near region A1 and the posture change limit remote region A2 may be defined to be closer to the neutral posture of the first robot 10 as the arm unit 12 of the first robot 10 extends from its initial position.

[0017] As shown in FIG. 1 , the second robot 20 is, for example, a known six-axis vertical articulated robot including an arm 21. The second robot 20 moves an object attached to the tip of the arm 21 by changing the posture and position of the arm 21. In this embodiment, the state in which the arm 21 is located in the center of its range of motion can be referred to as the state in which the arm 21 is in its initial position. In this embodiment, the object attached to the tip of the arm 21 is the first robot 10. In other words, the first robot 10 is attached to the second robot 20. Specifically, the base unit 11 of the first robot 10 is attached to the tip of the arm 21 of the second robot 20. In this embodiment, the posture of the first robot 10 can also be changed by the second robot 20. This allows the second robot 20 to change the relative posture of the tool T with respect to the workpiece W in this embodiment. 1 and 2, in this embodiment, the second robot 20 moves or rotates the first robot 10 when, for example, the posture of the first robot 10 is in the posture change limit vicinity region A1. In this way, the second robot 20 operates to compensate for the movable range of the end plate 13 of the first robot 10, which is a parallel link robot (details will be described later). In this embodiment, the second robot 20 has a role of, for example, moving or rotating the first robot 10 (particularly, the tool T attached to the end plate 13 of the first robot 10) so that the tool T approaches the workpiece W at a suitable angle before the first robot 10 performs work on the workpiece W. In this embodiment, the speed at which the posture of the second robot 20 is changed by the control means 35f (described later) is slower than the speed at which the posture of the first robot 10 is changed by the control means 35f. This preferably enables the second robot 20 to more effectively fulfill the above-mentioned role.

[0018] FIG. 4 is a schematic block diagram showing a specific example of the functional configuration of the control device 30 included in the robot control system 1. The control device 30 is configured using an information device such as a smartphone, tablet, personal computer, dedicated device, etc. In this embodiment, the control device 30 is a known computer. The control device 30 includes a communication unit 31, an input unit 32, an output unit 33, a storage unit 34, and a control unit 35.

[0019] The communication unit 31 is a communication device. The communication unit 31 may be configured as, for example, a network interface. The communication unit 31 communicates data with other devices via the network N in accordance with the control of the control unit 35. The communication unit 31 may be a device that performs wireless communication or a device that performs wired communication.

[0020] The input unit 32 is configured using existing input devices such as a keyboard, a pointing device (mouse, tablet, etc.), buttons, a touch panel, etc. The input unit 32 is operated by a user when inputting the user's instructions to the control device 30. The input unit 32 may be an interface for connecting the input device to the control device 30. In this case, the input unit 32 inputs an input signal generated in the input device in response to the user's input to the control device 30. The input unit 32 may be configured using a microphone and a voice recognition device. In this case, the input unit 32 acquires an acoustic signal generated by the user's speech, performs voice recognition on the words spoken by the user, and inputs character string information of the recognition result to the control device 30. The voice recognition process may be performed by the control unit 35. The input unit 32 may be configured in any way as long as it is capable of inputting the user's instructions to the control device 30.

[0021] The output unit 33 outputs information in a form that can be recognized by the user. The output unit 33 may be, for example, an image display device such as a liquid crystal display or an organic EL (Electro Luminescence) display. The output unit 33 may be an interface for connecting the image display device to the control device 30. In this case, the output unit 33 generates a video signal for displaying image data and outputs the video signal to the image display device connected to the output unit 33. The output unit 33 may be a device for outputting sound, such as a speaker. The output unit 33 may be an interface for connecting an audio output device, such as a speaker or headphones, to the control device 30. In this case, the output unit 33 generates an audio signal for reproducing audio data and outputs the audio signal to the audio output device connected to the output unit 33. The output unit 33 may be configured as a touch panel integrated with the input unit 32.

[0022] The storage unit 34 is configured using a storage device such as a magnetic hard disk drive or a semiconductor storage device. The storage unit 34 stores data used by the control unit 35. The storage unit 34 stores data required when the control unit 35 performs processing. The storage unit 34 functions as, for example, a movable range information storage unit 34a and a control information storage unit 34b.

[0023] The movable range information storage unit 34a stores movable range information. In this embodiment, the movable range information is information about the size of the posture change limit near region A1 and the posture change limit far region A2 within the posture change range of the first robot 10. As described above, in this embodiment, the posture change limit remote area A2 is set to become narrower as the distance between the center point 13a of the end plate 13 of the first robot 10 and the rotation center point C of the parallel link robot increases. Therefore, the movable range information storage unit 34a stores the relationship between the distance between the center point 13a of the end plate 13 of the first robot 10 and the rotation center point C of the parallel link robot, and the size of the posture change limit remote area A2. This distance is obtained, for example, by calculation based on information related to the position of the rotation center point C and the initial position of the center point 13a of the end plate 13, which are stored in the storage unit 34.

[0024] FIG. 5 shows a first example of the relationship between the distance between the center point 13a of the end plate 13 of the first robot 10 and the rotation center point C of the first robot 10, and the size of the posture change limit remote area A2. FIG. 6 shows a second example of the relationship between the distance between the center point 13a of the end plate 13 of the first robot 10 and the rotation center point C of the first robot 10, and the size of the posture change limit remote area A2. 5 and 6 are graphs in which the vertical axis indicates the size of the attitude change limit remote area A2 and the horizontal axis indicates the distance between the center point 13a and the rotation center point C. 5, the relationship between the distance between the center point 13a and the rotation center point C and the size of the attitude change limit remote area A2 may be set continuously. In this case, the size of the attitude change limit remote area A2 may be constant until the distance between the center point 13a and the rotation center point C reaches an arbitrary distance. Alternatively, as shown in FIG. 6, the relationship between the distance between the center point 13a and the rotation center point C and the size of the attitude change limit remote area A2 may be set in stages.

[0025] The control information storage unit 34b stores various information output by each means of the control unit 35, which will be described later, in a robot control method, which will be described later. The various information stored in the control information storage unit 34b is read from the control information storage unit 34b in a control step S6, which will be described later, and is reflected in the control of the first robot 10 and the second robot 20.

[0026] The control unit 35 is configured using a processor such as a CPU (Central Processing Unit) and a memory (main storage device). The control unit 35 functions when the processor executes a program. Note that all or part of the functions of the control unit 35 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The program may be recorded on a computer-readable recording medium. Examples of computer-readable recording media include portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and semiconductor storage devices (e.g., SSDs: Solid State Drives), as well as storage devices such as hard disks and semiconductor storage devices built into computer systems. The program may be transmitted via a telecommunications line.

[0027] The control unit 35 may execute, for example, an application installed on its own device (control device 30). A specific example of such an application is an application provided to the control device 30 as a dedicated application for the robot control system 1. Another specific example of such an application is a web browser application. Such an application may be pre-installed on the control device 30, or may be downloaded each time the robot control method according to this embodiment is executed. For example, when implemented as a web browser application, the control device 30 may download and execute the application from a device specified by a specific web server (for example, the web server itself or another server) in response to the control device 30 connecting to the web server. The control unit 35 operates according to the program of the application being executed.

[0028] The control unit 35 controls the robot control system 1 in accordance with information input by a user's operation, information regarding the posture of the first robot 10 received from the first robot 10, and the like. For example, the control unit 35 generates control information based on information input by a user operating the input unit 32, and transmits the control information to the first robot 10 and the second robot 20 using the communication unit 31. For example, when information transmitted from the first robot 10 is received by the communication unit 31 via the network N, the control unit 35 generates screen data based on the received information and displays the screen data on the output unit 33. Such screen data includes images and text indicating the information transmitted from the first robot 10. For example, when information transmitted from the first robot 10 is received by the communication unit 31 via the network N, the control unit 35 generates audio data based on the received information and outputs the audio data from the output unit 33. Alternatively, the control unit 35 may control the first robot 10 and the second robot 20 using information input by a user's operation, information regarding the posture of the first robot 10 received from the first robot 10, and the like.

[0029] In this embodiment, the control device 30, which is a computer, functions as a control device 30 having a control unit 35 equipped with a determination means 35a, a designation means 35b, a reception means 35c, an identification means 35d, a selection means 35e, and a control means 35f shown in Figure 4, by the control unit 35 executing a program.

[0030] The determination means 35a determines whether the posture of the first robot 10 is in the posture change limit near region A1 or the posture change limit far region A2. In this embodiment, the determination may be made, for example, based on whether the center point 13a of the end plate 13 is in the posture change limit near region A1 or the posture change limit far region A2. In this case, the position of the center point 13a of the end plate 13 and the angle of the end plate 13 may be calculated, for example, from the angles of each of the multiple arm units 12 of the first robot 10. The angle of the arm unit 12 may be calculated, for example, based on information about the rotation amount of a servo motor (not shown) that operates the arm unit 12. In this embodiment, the first robot 10 outputs information about its posture based on this information. The information output from the first robot 10 in this manner is received by the communication unit 31 via the network N. In addition, the control unit 35 may calculate information such as the posture of the tool T and the position of its tip by associating the information regarding the posture of the first robot 10 output as described above with information regarding the shape of the tool T pre-registered in the memory unit 34. The determination means 35a may determine the posture of the first robot 10 based on the various pieces of information received and calculated in this manner.

[0031] The designation means 35b designates the first relative orientation or the second relative orientation. In this embodiment, the designation of the first relative orientation or the second relative orientation is performed, for example, by the user inputting appropriate information via the input unit 32. In this embodiment, the designation of the first relative orientation or the second relative orientation by the designation means 35b may mean that the designation means 35b accepts the above-mentioned information input by the user. Specifically, for example, the user inputs information designating either the first relative orientation or the second relative orientation via the input unit 32. The user inputs information by, for example, selecting the first relative orientation or the second relative orientation by clicking a button indicating the first relative orientation or the second relative orientation in the screen data displayed on the output unit 33.

[0032] The receiving means 35c receives an instruction to change the posture of the second robot 20 to a neutral posture. In this embodiment, the instruction to change the posture of the second robot 20 to a neutral posture is given, for example, by the user inputting appropriate information via the input unit 32. In this embodiment, the receiving means 35c receiving the instruction to change the posture of the second robot 20 to a neutral posture may mean that the receiving means 35c receives the above-mentioned information input by the user. In this case, the information input by the user is given, for example, by the user selecting, by clicking, a button in the screen data displayed on the output unit 33 that issues an instruction to change the posture of the second robot 20 to a neutral posture.

[0033] The determination unit 35d determines whether or not to cause the control unit 35f to execute a control process. Whether or not to cause the control unit 35f to execute a control process is determined, for example, by a user. The user determines whether or not to cause the control unit 35f to execute a control process by inputting appropriate information via the input unit 32. In this embodiment, the determination by the determination unit 35d of whether or not to cause the control unit 35f to execute a control process may mean that the determination unit 35d accepts the information input by the user. In this case, the user inputs the information by, for example, selecting, by clicking, a button for determining whether or not to execute a control process in the screen data displayed on the output unit 33.

[0034] The selection means 35e selects either the first control mode or the second control mode. The first control mode is a mode in which the second robot 20 is controlled so as to change the relative posture between the tool T and the workpiece W while maintaining the posture of the first robot 10. The second control mode is a mode in which the posture of the first robot 10 is kept neutral and the second robot 20 is controlled so as to change the relative posture between the tool T and the workpiece W. The first control mode and the second control mode will be described in detail later. In the present embodiment, the selection of either the first control mode or the second control mode by the selection means 35e may mean that the selection means 35e accepts the above-described information input by the user. In this case, either the first control mode or the second control mode is selected, for example, by the user. The user selects either the first control mode or the second control mode by inputting appropriate information via the input unit 32. The user inputs information, for example, by the user selecting, by clicking, a button indicating the first control mode or the second control mode in the screen data displayed on the output unit 33.

[0035] The control means 35f controls the first robot 10 and the second robot 20. In this way, the relative posture of the tool T and the workpiece W is changed. Below, five examples of the control method of the first robot 10 and the second robot 20 by the control means 35f will be explained. Of the following five examples, the first example is the basic operation, and the other four examples (examples 2 to 5) are operations that are additionally added to example 1. The interrelationship between these will be explained in a flowchart showing the overall control.

[0036] A first example of the control of the first robot 10 and the second robot 20 by the control means 35f will be described. FIG. 7 is a diagram showing a state in which the first robot 10 is at an initial position in the first embodiment. FIG. 8 is a diagram showing a state in which the first robot 10 is in the posture change limit remote area A2 in the first embodiment. FIG. 9 is a diagram showing a case in which the first robot 10 is in the posture change limit vicinity area A1 and the second robot 20 operates in the first control mode in the first embodiment. FIG. 10 is a diagram showing a case where the second robot 20 operates in the second control mode in the first embodiment. In the first example, the control means 35f controls the first robot 10 and the second robot 20 to change the relative posture between the tool T and the workpiece W, for example, based on the determination result of the determination means 35a. That is, the control means 35f controls the first robot 10 and the second robot 20 based on the determination result by the determination means 35a as to whether the posture of the first robot 10 is in the posture change limit near region A1 or the posture change limit far region A2.

[0037] In this embodiment, when the posture of the first robot 10 is in the posture change limit near region A1, the control means 35f controls the second robot 20 to change the relative posture between the tool T and the workpiece W. When the posture of the first robot 10 is in the posture change limit remote region A2, the control means 35f controls the first robot 10 to change the relative posture between the tool T and the workpiece W. Specifically, this is as follows.

[0038] As shown in Fig. 7, when the first robot 10 is in its initial position, the posture of the first robot 10 is in the posture change limit remote region A2. When the first robot 10 starts to change its posture from this state, the posture of the first robot 10 changes while remaining in the posture change limit remote region A2, as shown in Fig. 8. As the first robot 10 continues to change its posture, the posture of the first robot 10 eventually reaches a state in the posture change limit vicinity region A1, as shown in Fig. 9. When this state is reached, the control means 35f operates the second robot 20. In this embodiment, the range of change in the posture of the first robot 10 depends on the relative posture between the second robot 20 that holds the first robot 10 and the rotation center point C of the first robot 10. The range of change in the posture of the first robot 10 changes as the first robot 10 moves or rotates due to the second robot 20, as shown in FIG. 9 or FIG. 10.

[0039] First, the control of the first robot 10 and the second robot 20 in the first control mode shown in FIG. 9 will be described. That is, when the determination means 35a determines that the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 so that the posture of the tool T changes in the direction in which the posture of the first robot 10 is changing from the neutral posture while maintaining the posture of the first robot 10, as shown in FIG. 9. That is, the second robot 20 moves or rotates the entire first robot 10 so that the end plate 13 of the first robot 10 further changes its posture beyond the movable range. For example, as shown in FIG. 9, when the posture of the first robot 10 changes so that the tool T rotates counterclockwise around the second axis Sf2, the control means 35f controls the second robot 20 so that the entire first robot 10 rotates counterclockwise around the second axis Sf2. In the example described above, the posture of the first robot 10 is maintained, and therefore the relative posture between the first robot 10 and the second robot 20 does not change. 9, the posture of the first robot 10 is located in the posture change limit vicinity area A1 even after the first robot 10 is moved by the second robot 20. Such a first control mode allows the posture of the tool T to be changed more smoothly.

[0040] Next, the control of the first robot 10 and the second robot 20 in the second control mode shown in Fig. 10 will be described. That is, when the determination means 35a determines that the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 so that the posture of the tool T changes in the direction in which the posture of the first robot 10 has changed from the neutral posture while keeping the posture of the first robot 10 in a neutral posture, as shown in Fig. 10. For example, when the posture of the first robot 10 has changed so that the tool T rotates counterclockwise around the second axis Sf2 as shown in Fig. 10, the control means 35f controls the second robot 20 so that the first robot 10 as a whole rotates counterclockwise around the second axis Sf2 while causing the tool T to rotate clockwise around the second axis Sf2. In the above example, when the second robot 20 operates because the posture of the first robot 10 is positioned in the posture change limit vicinity area A1, the second robot 20 does not operate until the posture of the first robot 10 is again positioned in the posture change limit vicinity area A1. Such a second control mode makes it easier to provide a margin for the posture of the first robot 10. Therefore, the workability of the first robot 10 can be improved. By performing the above-described control, the second robot 20 operates to compensate for the range of movement of the end plate 13.

[0041] After the first robot 10 and the second robot 20 have operated as described above, the first robot 10 and the second robot 20 each operate to return to a neutral posture, for example, based on an instruction from a user. At this time, when changing the posture of the first robot 10 from the posture change limit near region A1 toward the posture change limit far region A2, the control means 35f preferably controls the first robot 10 and the second robot 20 in this order. In this way, by first returning the posture of the first robot 10 toward the neutral posture and then returning the posture of the second robot 20 to the neutral posture, it is possible to make it easier to provide some leeway to the posture of the first robot 10.

[0042] A second example of the control of the first robot 10 and the second robot 20 by the control means 35f will now be described. The control according to the second example may be performed simultaneously with the control according to the first example described above. In the second example, for example, when a first relative attitude is designated by the designation means 35b, the control means 35f may control the first robot 10 and the second robot 20 to change the first relative attitude based on the determination result of the determination means 35a. Also, when a second relative attitude is designated by the designation means 35b, the control means 35f may control the first robot 10 and the second robot 20 to change the second relative attitude based on the determination result of the determination means 35a. As described above, the first relative attitude or the second relative attitude is specified by the user. The control means 35f may be configured to appropriately change the first relative attitude or the second relative attitude in accordance with the user's designation, thereby enabling the first robot 10 and the second robot 20 to be controlled in accordance with the user's intentions.

[0043] A description will be given of a third example of the control by the control means 35f of the first robot 10 and the second robot 20. The control according to the third example may be performed with priority over the control according to the first example described above, for example. In a third example, the control means 35f may control the second robot 20 to change its posture to a neutral posture, for example, when the reception means 35c receives an instruction to change the posture of the second robot 20 to a neutral posture. As described above, the user issues an instruction to set the second robot 20 to the neutral posture. The control means 35f may appropriately set the second robot 20 to the neutral posture in accordance with the user's instruction, thereby enabling the second robot 20 to be controlled in accordance with the user's intentions.

[0044] A fourth example of the control of the first robot 10 and the second robot 20 by the control means 35f will be described. Whether or not the control according to the first example described above is performed may be determined by the control according to the fourth example. In the fourth example, the control means 35f may, for example, execute the control process when the identification means 35d identifies that the control process should be executed, and may not execute the control process when the identification means 35d identifies that the control process should not be executed. As described above, whether or not to execute the control process by the control means 35f is determined by the user. The control means 35f may appropriately control or not control the first robot 10 and the second robot 20 in accordance with the user's instructions, thereby enabling the first robot 10 and the second robot 20 to be controlled more in line with the user's intentions.

[0045] A fifth example of control by the control means 35f of the first robot 10 and the second robot 20 will be described. The control according to the fifth example may be performed simultaneously with the control according to the first example described above. In the fifth example, for example, when the posture of the first robot 10 is in the posture change limit vicinity region A1, if the selection means 35e selects the first control mode, the control means 35f may control the first robot 10 and the second robot 20 in the above-described first control mode. Also, if the selection means 35e selects the second control mode, the control means 35f may control the first robot 10 and the second robot 20 in the above-described second control mode. As described above, the first control mode or the second control mode is selected by the user. The control means 35f may perform control in the first control mode or the second control mode in accordance with an instruction from the user, thereby enabling the first robot 10 and the second robot 20 to be controlled in accordance with the user's intentions. The robot control system 1 according to this embodiment is configured as described above.

[0046] (Robot control method) Next, a robot control method in the robot control system 1 of this embodiment will be described. FIG. 11 is a flowchart of a robot control method according to the embodiment. As shown in FIG. 11, the robot control method in this embodiment includes a designation step S1, a reception step S2, a specification step S3, a selection step S4, a determination step S5, and a control step S6. In this embodiment, each of the above steps begins when the first robot 10 begins to move the tool T, and ends when the first robot 10 finishes working on the workpiece W using the tool T. The first robot 10 starts to work, for example, when a user instructs the first robot 10 to start moving the tool T. The first robot 10 ends its movement, for example, when a user instructs the first robot 10 to end the work using the tool T. These instructions from the user may be given, for example, by the user inputting appropriate information via the input unit 32.

[0047] In this embodiment, each of the above steps ends when the user inputs an instruction to end the work using the tool T (S0: YES). If the user does not input an instruction to end the work (S0: NO), each of the above steps is repeated. In this embodiment, in each of the above steps except for control step S6, various pieces of information are output as appropriate by each means of the control unit 35, as described below. All of the various pieces of information output in this manner are stored in the control information storage unit 34b of the control unit 35. As described below, in control step S6, the control means 35f reads out the various pieces of information stored in the control information storage unit 34b as appropriate, and controls the first robot 10 and the second robot 20.

[0048] Here, for example, when each of the above steps is performed for the first time, that is, when the number of repetitions of each step is 1, none of the various types of information is stored in the control information storage unit 34b. As each step is performed from this state, each of the various types of information is appropriately stored in the control information storage unit 34b. When each of the above steps is being performed for the second or subsequent time, i.e., when each step is repeated two or more times, the various information stored in the previous step may remain stored in the control information storage unit 34b. Even if the various information is not output in each step from the second time onward, the control means 35f may perform control step S6 based on the various information stored in the control information storage unit 34b at the time of the previous step. This may eliminate the need for the user to input various information each time each step is repeated. Note that various information may be overwritten as appropriate if it is different from the information output in the previous step.

[0049] The designation step S1 is a step in which the designation means 35b receives designation of the first relative attitude or the second relative attitude from the user. In the designation step S1, first, the designation means 35b refers to the information input by the user. In the designation step S1, when a designation of a first relative attitude is accepted, the designation means 35b outputs first relative attitude information. When a designation of a second relative attitude is accepted, the designation means 35b outputs second relative attitude information. The information output by the designation means 35b is stored in the control information storage unit 34b. If the user does not specify either the first or second relative orientation in the specification step S1, the specification means 35b outputs neither the first relative orientation information nor the second relative orientation information. In this case, the control means 35f may refer to the information output in the previous specification step S1 in the control step S6. Furthermore, the user may select both the first relative attitude and the second relative attitude in the designation step S1, in which case the designation means 35b may output both the first relative attitude information and the second relative attitude information. Furthermore, in the designation step S1, the user may designate that the designation of the first relative attitude or the second relative attitude made at the time of the previous designation step S1 is to be cancelled. In this case, the first relative attitude information or the second relative attitude information stored in the control information storage unit 34b may be deleted.

[0050] The receiving step S2 is a step in which the receiving means 35c receives an instruction from the user to set the posture of the second robot 20 to a neutral posture. In the receiving step S2, the receiving means 35c first refers to the information input by the user. In the receiving step S2, if an instruction to set the posture of the second robot 20 to a neutral posture is received, the receiving means 35c outputs neutral posture information. If an instruction to set the posture of the second robot 20 to a neutral posture is not received, the receiving means 35c does not output neutral posture information. The neutral posture information output by the receiving means 35c is stored in the control information storage unit 34b. If the user does not input an instruction to set the posture of the second robot 20 to a neutral posture and the reception means 35c does not output neutral posture information, and the neutral posture information output in the previous reception step S2 is stored in the control information storage unit 34b, the control means 35f may refer to the neutral posture information stored in the previous reception step S2 in control step S6. Furthermore, in the receiving step S2, the user may issue an instruction to cancel the instruction issued in the previous receiving step S2 to set the posture of the second robot 20 to the neutral posture. In this case, the neutral posture information stored in the control information storage unit 34b may be deleted.

[0051] The specifying step S3 is a step in which the specifying means 35d receives a specification from the user as to whether or not to cause the control means 35f to execute a control process. In the specifying step S3, first, the specifying means 35d refers to the information input by the user. In the determination step S3, if the determination unit 35d receives a determination that the control process is to be executed by the control unit 35f, the determination unit 35d outputs execution information. If the determination unit 35d receives a determination that the control process is not to be executed by the control unit 35f, the determination unit 35d outputs non-execution information. The information output by the determination unit 35d is stored in the control information storage unit 34b. When the specifying step S3 is performed for the first time, i.e., when the number of repetitions of the specifying step S3 is 1, and the user does not specify whether or not to execute the control process by the control means 35f, the specifying means 35d may automatically output either the execution information or the non-execution information. In such a case, whether the execution information or the non-execution information is to be output may be set in advance before the flow of the robot control method according to this embodiment is started. When the identification step S3 is performed for the second time or later, i.e., when the number of times the identification step S3 is repeated is two or more, and the user does not specify whether or not to execute the control processing by the control means 35f, the control means 35f may refer to the information output in the previous identification step S3 in control step S6. In this embodiment, the control processing targeted in the identification step S3 is a control processing related to the operation of the second robot 20 to complement the movable range of the end plate 13 of the first robot 10 (details will be described later).

[0052] The selection step S4 is a step in which the selection means 35e receives a selection of the first control mode or the second control mode from the user. In the selection step S4, the selection means 35e first refers to the information input by the user. In the selection step S4, if the selection of the first control mode is accepted, the selection means 35e outputs first control mode information. If the selection of the second control mode is accepted, the selection means 35e outputs second control mode information. The information output by the selection means 35e is stored in the control information storage unit 34b. When the selection step S4 is performed for the first time, i.e., when the number of repetitions of the selection step S4 is 1, if the user does not select either the first control mode or the second control mode, the selection means 35e may automatically output either the first control mode information or the second control mode information. In such a case, whether the first control mode information or the second control mode information is to be output may be set in advance before the flow of the robot control method according to this embodiment is started. When selection step S4 is performed for the second time or later, i.e., when selection step S4 is repeated two or more times, if the user does not select either the first control mode or the second control mode, control means 35f may refer to the information output in the previous selection step S4 in control step S6.

[0053] In the determination step S5, the determination means 35a determines whether the posture of the first robot 10 is in the posture change limit near region A1 or the posture change limit far region A2. In the determination step S5, the determination means 35a first refers to information about the posture of the first robot 10 transmitted from the first robot 10. When the determination means 35a determines that the posture of the first robot 10 is in the posture change limit near region A1, the determination means 35a outputs near region information. When the determination means 35a determines that the posture of the first robot 10 is in the posture change limit far region A2, the determination means 35a outputs far region information. The information output by the determination means 35a is stored in the control information storage unit 34b. In this embodiment, the determination by the determination means 35a in determination step S5 may be made each time the flow of the robot control method is repeated. The near area information or far area information output by the determination means 35a may be overwritten each time determination step S5 is performed.

[0054] Control step S6 is a step in which the control means 35f controls the first robot 10 and the second robot 20 based on the information output in the above steps. In control step S6, the control means 35f reads out various pieces of information stored in the control information storage unit 34b. In control step S6, for example, the control according to the first example described above is performed based on the determination result of the determination means 35a. That is, the first robot 10 and the second robot 20 are controlled so as to change the relative posture between the tool T and the workpiece W. Specifically, this is as follows. When the remote area information is read from the control information storage unit 34b, the control means 35f changes only the posture of the first robot 10. In other words, the control means 35f changes the relative posture between the tool T and the workpiece W by only the first robot 10. Furthermore, when the vicinity area information is read out from the control information storage unit 34b, the control means 35f changes the relative posture between the tool T and the workpiece W by both the first robot 10 and the second robot 20. Specifically, for example, the control means 35f controls the second robot 20 so that the posture of the tool T changes in the direction in which the posture of the first robot 10 changes from the neutral posture. In this embodiment, in control step S6, the above control is performed as a base, and the following control is also performed.

[0055] In the control step S6, for example, the control according to the second example described above may be performed based on the designation of the first relative attitude or the second relative attitude received in the designation step S1. When the first relative posture information is read out from the control information storage unit 34b, the control means 35f controls the first robot 10 and the second robot 20 so as to change the first relative posture. When the second relative posture information is read out from the control information storage unit 34b, the control means 35f controls the first robot 10 and the second robot 20 so as to change the second relative posture. When both the first relative posture information and the second relative posture information are read out from the control information memory unit 34b, the control means 35f may control the first robot 10 and the second robot 20 to change both the first relative posture and the second relative posture.

[0056] In the control step S6, for example, the control according to the fifth example described above may be performed based on the selection of the first control mode or the second control mode accepted in the selection step S4. Specifically, the control is performed as follows. When the first control mode information is read out from the control information storage unit 34b, the control means 35f controls the first robot 10 and the second robot 20 in the first control mode. When the second control mode information is read out from the control information storage unit 34b, the control means 35f controls the first robot 10 and the second robot 20 in the second control mode.

[0057] In the control step S6, for example, the control according to the fourth example described above may be performed based on the determination of whether or not to execute the control process by the control means 35f, which is received in the determination step S3. Specifically, the control is performed as follows. When execution information is read from the control information storage unit 34b, the control means 35f may execute the control processing of the first robot 10 and the second robot 20. When non-execution information is read from the control information storage unit 34b, the control means 35f may not execute the control processing of the first robot 10 and the second robot 20. Here, as described above, the control processing targeted in the identification step S3 is control processing related to the operation of the second robot 20 to complement the movable range of the end plate 13 of the first robot 10. Specifically, it is as follows. For example, when execution information is output from the specifying means 35d in the specifying step S3, if the posture of the first robot 10 is in the posture change limit vicinity area A1, the second robot 20 is operated. When non-execution information is output from the specifying means 35d in the specifying step S3, even if the posture of the first robot 10 is in the posture change limit vicinity area A1, the second robot 20 is not operated and only the first robot 10 is operated.

[0058] In the control step S6, for example, the control according to the third example described above may be performed based on an instruction from the user to set the posture of the second robot 20 to a neutral posture, which was received in the receiving step S2. Specifically, the control is performed as follows. When the neutral posture information is read from the control information storage unit 34b, the control means 35f may control the second robot 20 to assume the neutral posture, giving priority to any of the above information. The robot control method according to this embodiment is carried out as described above.

[0059] 12 is a diagram illustrating an outline of an example of the hardware configuration of an information processing device 90 applied to an embodiment. The information processing device 90 includes a processor 91, a main memory device 92, a communication interface 93, an auxiliary memory device 94, an input / output interface 95, and an internal bus 96. The processor 91, the main memory device 92, the communication interface 93, the auxiliary memory device 94, and the input / output interface 95 are communicably connected to each other via the internal bus 96. The information processing device 90 may be applied to, for example, a control device 30. In this case, for example, the communication unit 31 may be configured using the communication interface 93. For example, the memory unit 34 may be configured using the auxiliary memory device 94. Furthermore, the control unit 35 may be configured using the processor 91 and the main memory device 92.

[0060] As described above, the robot control system 1 according to this embodiment includes a determination unit 35a and a control unit 35f. The determination unit 35a determines whether the posture of the first robot 10 is in the posture change limit vicinity region A1, which is a region close to the limit of the posture change range of the first robot 10, or in the posture change limit remote region A2, which is a region farther from the limit of the posture change range than the posture change limit vicinity region A1. The control unit 35f controls the first robot 10 and the second robot 20 to change the relative posture of the tool T with respect to the workpiece W based on the determination result of the determination unit 35a. This allows the first robot 10 and the second robot 20 to operate appropriately to change the relative posture of the tool T attached to the first robot 10 with respect to the workpiece W, depending on whether the posture of the first robot 10 is in the posture change limit vicinity region A1. This increases the relative movable range of the posture of the tool T with respect to the workpiece W. In other words, it becomes easier to change the relative posture of the tool T with respect to the workpiece W. Furthermore, the above-described control of the first robot 10 and the second robot 20 can be performed without, for example, calculating the dynamic manipulability ellipsoid, and therefore the first robot 10 and the second robot 20 can be controlled without performing complicated calculations.

[0061] Furthermore, the first robot 10 is attached to the second robot 20. When the determination means 35a determines that the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 so that the posture of the tool T changes in the direction in which the posture of the first robot 10 is changing from the neutral posture. As a result, for example, when the first robot 10 is attached to the second robot 20, the second robot 20 can be more appropriately operated so that the relative posture of the tool T, i.e., the posture relative to the workpiece W, is changed by changing the posture of the tool T. Therefore, the posture of the tool T can be changed further than when the posture of the tool T is changed only by the first robot 10. Therefore, the movable range of the tool T can be further increased. Therefore, the relative movable range of the posture of the tool T with respect to the workpiece W can be increased.

[0062] The robot controller 35f further includes a designation means 35b. The relative orientation of the tool T with respect to the workpiece W includes a first relative orientation, which is a relative orientation about the first axis Sf1 of the first robot 10, and a second relative orientation, which is a relative orientation about the second axis Sf2 of the first robot 10. When the first relative orientation is designated by the designation means 35b, the control means 35f controls the first robot 10 and the second robot 20 to change the first relative orientation based on the determination result of the determination means 35a. When the second relative orientation is designated by the designation means 35b, the control means 35f controls the first robot 10 and the second robot 20 to change the second relative orientation based on the determination result of the determination means 35a. This allows the first robot 10 and the second robot 20 to operate appropriately so as to change the first relative orientation or the second relative orientation, whichever is designated by a user or the like. This improves the operability of the first robot 10 and the second robot 20.

[0063] The first robot 10 is a parallel link robot. The movable range of the end plate 13 of the parallel link robot becomes narrower as the distance between the center point 13a of the end plate 13 and the rotation center point C of the parallel link robot increases. Therefore, the posture change limit remote area A2 becomes narrower as the distance between the center point 13a of the end plate 13 of the parallel link robot and the rotation center point C of the parallel link robot increases. This makes it possible to appropriately set the limit range of posture change of the parallel link robot according to the distance between the center point 13a of the end plate 13 and the rotation center point C.

[0064] Furthermore, when the posture of the first robot 10 is in the posture change limit near region A1, the control means 35f controls the second robot 20 to change the relative posture of the tool T with respect to the workpiece W. Furthermore, when the posture of the first robot 10 is in the posture change limit far region A2, the control means 35f controls the first robot 10 to change the relative posture of the tool T with respect to the workpiece W. In other words, depending on whether the posture of the first robot 10 is in the posture change limit near region A1, the control means 35f appropriately controls either the first robot 10 or the second robot 20. This makes it possible to prevent the first robot 10 from operating beyond the limit of the posture change range. Therefore, it is possible to appropriately and reliably change the relative posture of the tool T with respect to the workpiece W while minimizing the influence of the performance of the first robot 10.

[0065] The robot controller 35 further includes a receiving unit 35c that receives an instruction to set the second robot 20 to a neutral position. When the receiving unit 35c receives an instruction to set the second robot 20 to a neutral position, the control unit 35f controls the second robot 20 to set the second robot 20 to a neutral position. This allows the second robot 20 to be set to a neutral position in response to a user instruction. This improves the operability of the second robot 20.

[0066] Furthermore, the speed at which the control means 35f changes the posture of the second robot 20 is slower than the speed at which the control means 35f changes the posture of the first robot 10. This makes it easier to control, for example, the operation of the second robot 20 to change the relative posture of the tool T with respect to the workpiece W. This therefore improves the workability of the robot control system 1.

[0067] Furthermore, when changing the posture of the first robot 10 from the posture change limit near region A1 toward the posture change limit far region A2, the control means 35f controls the first robot 10 and then the second robot 20. In this way, by changing the posture of the first robot 10 from the posture change limit near region A1 to the posture change limit far region A2 in advance and then operating the second robot 20, it is possible to make it easier to provide some leeway to the posture of the first robot 10.

[0068] The robot control system 1 further includes a specification unit 35d that specifies whether or not to execute a control process by the control unit 35f. The control unit 35f executes a control process when the specification unit 35d specifies that the control process should be executed, and does not execute a control process when the specification unit 35d specifies that the control process should not be executed. This allows the specification unit 35d to specify whether or not to execute a control process based on an instruction from a user, so that the control process by the control unit 35f can be executed based on the user's intention. This makes it easier to reflect the user's intention, thereby improving the operability of the robot control system 1.

[0069] The control system further includes a selection means 35e for selecting either the first control mode or the second control mode. When the selection means 35e selects the first control mode while the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 to change the relative posture of the tool T with respect to the workpiece W while maintaining the posture of the first robot 10. This makes it easier to continuously change the posture of the tool T attached to the first robot 10. Furthermore, when the posture of the first robot 10 is in the posture change limit vicinity region A1 and the selection means 35e selects the second control mode, the control means 35f controls the second robot 20 to bring the posture of the first robot 10 to a neutral posture and change the relative posture of the tool T with respect to the workpiece W. This makes it easier to return the posture of the first robot 10 to the neutral posture. Therefore, it is easier to provide a margin for the posture of the first robot 10. By making the above-described operations of the first robot 10 and the second robot 20 selectable by the selection means 35e, the above-described operations can be executed based on the user's intention. Therefore, by making it easier to reflect the user's intention, the workability of the robot control system 1 can be improved.

[0070] (Second embodiment) Next, a robot control system 1 according to a second embodiment of the present disclosure will be described with reference to FIGS. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with only the differences being described. FIG. 13 is a diagram showing a state in which the first robot 10 is at an initial position in the second embodiment. FIG. 14 is a diagram showing a state in which the first robot 10 is in the posture change limit remote area A2 in the second embodiment. FIG. 15 is a diagram showing a case in which the first robot 10 is in the posture change limit vicinity area A1 and the second robot 20 operates in the first control mode in the second embodiment. FIG. 16 is a diagram showing a case where the second robot 20 operates in the second control mode in the second embodiment.

[0071] In the second embodiment, the second robot 20 holds a workpiece W as shown in Fig. 13. In the second embodiment, the position of the base 11 of the first robot 10 is fixed. As a result, in the first robot 10 of the second embodiment, only the posture of the end plate 13 changes, and the posture of the first robot 10 itself does not change. In the second embodiment, the first robot 10 may be fixed to, for example, a support pillar or wall (not shown).

[0072] In the second embodiment, the second robot 20 can change the relative posture of the tool T with respect to the workpiece W. In the second embodiment, moving the tool T and the workpiece W relative to each other means moving both the tool T and the workpiece W. In the second embodiment, the second robot 20 has the role of, for example, changing the posture of the workpiece W before the first robot 10 performs work on the workpiece W, thereby bringing the tool T closer to the workpiece W at a suitable angle.

[0073] 13 and 14, the robot control system 1 of the second embodiment having the above configuration is the same as the first embodiment until the first robot 10 starts changing its posture from the initial position and reaches the posture change limit vicinity region A1. In the second embodiment, when the determination means 35a determines that the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 so that the posture of the workpiece W changes in the direction opposite to the direction in which the posture of the first robot 10 is changing from the neutral posture. Specifically, this is as follows.

[0074] First, the control of the first robot 10 and the second robot 20 in the first control mode shown in FIG. 15 will be described. That is, when the determination means 35a determines that the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 so that the posture of the workpiece W changes in the direction opposite to the direction in which the posture of the first robot 10 is changing from the neutral posture while maintaining the posture of the first robot 10, as shown in FIG. 15. That is, when the posture of the first robot 10 approaches the limit of its movable range, the second robot 20 changes the posture of the workpiece W, thereby changing the relative posture between the tool T and the workpiece W beyond the movable range of the posture of the first robot 10. For example, when the posture of the first robot 10 changes so that the tool T rotates clockwise around the first axis Sf1, the control means 35f controls the second robot 20 so that the workpiece W rotates counterclockwise around the first axis Sf1.

[0075] Next, the control of the first robot 10 and the second robot 20 in the second control mode shown in Fig. 16 will be described. That is, when the determination means 35a determines that the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 so that the posture of the first robot 10 is kept neutral, while the posture of the workpiece W is changed in the direction opposite to the direction in which the posture of the first robot 10 changed from the neutral posture, as shown in Fig. 16. For example, when the posture of the first robot 10 has changed so that the tool T rotates clockwise about the first axis Sf1, the first robot 10 controls the second robot 20 so that the tool T rotates counterclockwise about the first axis Sf1, while the workpiece W rotates counterclockwise about the first axis Sf1. By performing the above-described control, the second robot 20 operates to compensate for the range of movement of the end plate 13. In the above respects, the second embodiment differs from the first embodiment.

[0076] As described above, according to the robot control system 1 of the second embodiment, the second robot 20 holds the workpiece W. When the determination means 35a determines that the posture of the first robot 10 is in the posture change limit vicinity region A1, the control means 35f controls the second robot 20 so that the posture of the workpiece W changes in the direction opposite to the direction in which the posture of the first robot 10 is changing from the neutral posture. As a result, for example, when the second robot 20 holds the workpiece W, the second robot 20 can be more appropriately operated so that the relative posture of the tool T with respect to the workpiece W is changed by changing the posture of the workpiece W. Therefore, the relative posture of the tool T with respect to the workpiece W can be changed more than when only the posture of the tool T is changed by the first robot 10. Therefore, the relative movable range of the posture of the tool T with respect to the workpiece W can be increased.

[0077] The technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. FIG. 17 shows a modified example of the workpiece W. In this embodiment, the workpiece W has been described as having a convex shape, but as shown in FIG. 17, the workpiece W may also have a concave shape. Furthermore, for example, a posture change limit intermediate region may be provided between the posture change limit near region A1 and the posture change limit far region A2, so that the movement speed of the second robot 20 may be changed depending on whether the posture of the first robot 10 is in the posture change limit near region A1 or in the posture change limit intermediate region. In addition, in a configuration in which the first robot 10 is attached to the second robot 20, a third robot (not shown) for changing the posture of the workpiece W may be further provided. Furthermore, the second robot 20 has been described as a known six-axis vertical articulated robot, but any other robot may be used as long as it can ensure the above-mentioned functions. Furthermore, the speed at which the posture of the second robot 20 is changed may be the same as the speed at which the posture of the first robot 10 is changed, or may be faster than the speed at which the posture of the first robot 10 is changed. In addition, when the control means 35f changes the posture of the first robot 10 from the posture change limit near area A1 toward the posture change limit far area A2, the control means 35f may control the first robot 10 and the second robot 20 in the order of the second robot 20 and the first robot 10.

[0078] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate.

[0079] (Addendum) The robot control system according to the embodiment can be understood, for example, as follows.

[0080] <1> A robot control system according to one embodiment of the present disclosure is a robot control system comprising a first robot to which a tool is attached and a second robot capable of changing the relative attitude of the tool with respect to a workpiece, characterized in that the system comprises a determination means for determining whether the attitude of the first robot is in an attitude change limit near area, which is an area close to the limit of the change range of the attitude of the first robot, or in an attitude change limit far area, which is an area farther from the limit than the attitude change limit near area, and a control means for controlling the first robot and the second robot to change the relative attitude based on the determination result of the determination means.

[0081] The robot control system includes a determination means and a control means. The determination means determines whether the posture of the first robot is in a posture change limit near region, which is a region close to the limit of the posture change range of the first robot, or in a posture change limit far region, which is a region farther from the limit of the posture change range than the posture change limit near region. The control means controls the first robot and the second robot to change the relative posture of the tool with respect to the workpiece based on the determination result of the determination means. This allows the first robot and the second robot to be operated appropriately to change the relative posture of the tool attached to the first robot, i.e., the relative posture with respect to the workpiece, depending on whether the posture of the first robot is in the posture change limit near region. This increases the relative movable range of the posture of the tool with respect to the workpiece. In other words, it makes it easier to change the relative posture of the tool with respect to the workpiece. Furthermore, the above-described control of the first robot and the second robot can be performed without, for example, calculating the dynamic manipulability ellipsoid. Therefore, the first robot and the second robot can be controlled without performing complex calculations.

[0082] <2> the above <1> In the robot control system according to the above, the first robot may be attached to the second robot, and the control means may control the second robot so that the attitude of the tool changes in the direction in which the attitude of the first robot is changing from a neutral attitude when the determination means determines that the attitude of the first robot is in the area near the attitude change limit.

[0083] The first robot is attached to the second robot. When the determination means determines that the posture of the first robot is in the posture change limit vicinity region, the control means controls the second robot so that the posture of the tool changes in the direction in which the posture of the first robot is changing from the neutral posture. As a result, for example, when the first robot is attached to the second robot, the second robot can be more appropriately operated so that the relative posture of the tool, i.e., the posture relative to the workpiece, is changed by changing the posture of the tool. Therefore, the posture of the tool can be changed more than when the posture of the tool is changed only by the first robot. Therefore, the movable range of the tool can be further increased. Therefore, the relative movable range of the posture of the tool with respect to the workpiece can be increased.

[0084] <3> the above <1> or <2> In the robot control system according to the above, the second robot may hold the workpiece, and the control means may control the second robot so that the attitude of the workpiece changes in a direction opposite to the direction in which the attitude of the first robot is changing from a neutral attitude when the determination means determines that the attitude of the first robot is in the area near the attitude change limit.

[0085] The second robot holds a workpiece. When the determination means determines that the posture of the first robot is in the posture change limit vicinity region, the control means controls the second robot so that the posture of the workpiece changes in the direction opposite to the direction in which the posture of the first robot is changing from the neutral posture. This allows the second robot to operate more appropriately, for example, when the second robot is holding a workpiece, so that the relative posture of the tool with respect to the workpiece is changed by changing the posture of the workpiece. Therefore, the relative posture of the tool with respect to the workpiece can be changed more than when only the posture of the tool is changed by the first robot. Therefore, the relative movable range of the posture of the tool with respect to the workpiece can be increased.

[0086] <4> the above <1> from <3> A robot control system according to any one of the above aspects may further include a designation means 35b, wherein the relative attitude includes a first relative attitude that is a relative attitude around a first axis of the first robot and a second relative attitude that is a relative attitude around a second axis of the first robot, and the control means may, when the first relative attitude is designated by the designation means 35b, control the first robot and the second robot to change the first relative attitude based on the determination result of the determination means, and when the second relative attitude is designated by the designation means 35b, control the first robot and the second robot to change the second relative attitude based on the determination result of the determination means.

[0087] The robot further includes a designation means 35b. The relative orientation of the tool with respect to the workpiece includes a first relative orientation, which is a relative orientation around a first axis of the first robot, and a second relative orientation, which is a relative orientation around a second axis of the first robot. When the first relative orientation is designated by the designation means 35b, the control means controls the first robot and the second robot to change the first relative orientation based on the determination result of the determination means. When the second relative orientation is designated by the designation means 35b, the control means controls the first robot and the second robot to change the second relative orientation based on the determination result of the determination means. This allows the first robot and the second robot to operate appropriately so as to change the first relative orientation or the second relative orientation, whichever is designated by a user or the like. This improves the operability of the first robot and the second robot.

[0088] <5> the above <1> from <4> In the robot control system according to any one of the above aspects, the first robot may be a parallel link robot, and the posture change limit remote region may be narrower as the distance between the center point of an end plate of the parallel link robot and the center point of rotation of the parallel link robot increases.

[0089] The first robot is a parallel link robot, and the movable range of the end plate of the parallel link robot becomes narrower as the distance between the center point of the end plate and the rotation center point of the parallel link robot increases. Therefore, the farther the distance between the center point of the end plate of the parallel link robot and the center point of rotation of the parallel link robot, the narrower the posture change limit remote region becomes. This makes it possible to appropriately set the limit range of posture change of the parallel link robot according to the distance between the center point of the end plate and the center point of rotation.

[0090] <6> the above <1> from <5> In the robot control system according to any one of the above aspects, the control means may be configured to control the second robot to change the relative attitude when the attitude of the first robot is in the attitude change limit near region, and to control the first robot to change the relative attitude when the attitude of the first robot is in the attitude change limit far region.

[0091] Furthermore, when the posture of the first robot is in the posture change limit near region, the control means controls the second robot to change the relative posture of the tool with respect to the workpiece. Furthermore, when the posture of the first robot is in the posture change limit far region, the control means controls the first robot to change the relative posture of the tool with respect to the workpiece. In other words, depending on whether the posture of the first robot is in the posture change limit near region, the control means appropriately controls either the first robot or the second robot. This makes it possible to prevent the first robot from operating beyond the limit of the posture change range. Therefore, it is possible to appropriately and reliably change the relative posture of the tool with respect to the workpiece while minimizing the influence of the performance of the first robot.

[0092] <7> the above <1> from <6> In any one of the above embodiments, the robot control system may further include a receiving means 35c that receives an instruction to set the posture of the second robot to a neutral posture, and the control means may be configured to control the second robot so as to set the posture of the second robot to a neutral posture when the receiving means 35c receives the instruction.

[0093] The robot further includes a receiving unit 35c that receives an instruction to set the second robot to a neutral position. When the receiving unit 35c receives an instruction to set the second robot to a neutral position, the control unit controls the second robot to set the second robot to a neutral position. This allows the second robot to set its position to a neutral position in response to a user's instruction. This improves the operability of the second robot.

[0094] <8> the above <1> from <7> In the robot control system according to any one of the above aspects, a configuration may be adopted in which the speed at which the posture of the second robot is changed by the control means is slower than the speed at which the posture of the first robot is changed by the control means.

[0095] Furthermore, the speed at which the control means changes the posture of the second robot is slower than the speed at which the control means changes the posture of the first robot. This makes it easier to control, for example, the operation of the second robot to change the relative posture of the tool with respect to the workpiece. This improves the workability of the robot control system.

[0096] <9> the above <1> from <8> In the robot control system according to any one of the above aspects, the control means may be configured to control the first robot and the second robot in that order when changing the posture of the first robot from the posture change limit near region to the posture change limit far region.

[0097] Furthermore, when changing the posture of the first robot from the posture change limit near region toward the posture change limit far region, the control means controls the first robot and then the second robot in this order. In this way, by changing the posture of the first robot from the posture change limit near region to the posture change limit far region in advance and then operating the second robot, it is possible to make it easier to provide some leeway in the posture of the first robot.

[0098] <10> the above <1> from <9> In a robot control system according to any one of the above aspects, the system may further include a determination means for determining whether or not to cause the control means to execute a control process, and the control means may execute the control process when the determination means determines that the control process is to be executed, and may not execute the control process when the determination means determines that the control process is not to be executed.

[0099] The robot control system further includes a specification unit that specifies whether or not to cause the control unit to execute a control process. The control unit executes the control process when the specification unit specifies that the control process should be executed, and does not execute the control process when the specification unit specifies that the control process should not be executed. This allows the control unit to execute the control process based on the user's intention, for example, by the specification unit specifying whether or not to execute the control process based on an instruction from the user. Therefore, by making it easier to reflect the user's intention, the operability of the robot control system can be improved.

[0100] <11> the above <1> from <10> The robot control system according to any one of the above aspects may further include a selection means for selecting either a first control mode or a second control mode, and the control means may be configured to control the second robot to change the relative attitude while maintaining the attitude when the attitude is in the attitude change limit vicinity region if the first control mode is selected by the selection means, and to control the second robot to set the attitude to a neutral attitude and change the relative attitude when the second control mode is selected by the selection means.

[0101] The control system further includes a selection means for selecting either the first control mode or the second control mode. When the selection means selects the first control mode when the orientation of the first robot is in the orientation change limit vicinity region, the control means controls the second robot to change the relative orientation of the tool with respect to the workpiece while maintaining the orientation of the first robot. This makes it easier to continuously change the orientation of the tool attached to the first robot. Furthermore, when the posture of the first robot is in the posture change limit vicinity region and the selection means selects the second control mode, the control means controls the second robot to bring the posture of the first robot to a neutral posture and change the relative posture of the tool with respect to the workpiece. This makes it easier to return the posture of the first robot to the neutral posture. Therefore, it is easier to provide a margin for the posture of the first robot. By making the above-described operations of the first robot and the second robot selectable by the selection means, the above-described operations can be executed based on the user's intention. Therefore, by making it easier to reflect the user's intention, the workability of the robot control system can be improved.

[0102] <12> A robot control method according to one aspect of the present disclosure is a control method for a robot control system including a first robot to which a tool is attached and a second robot capable of changing the relative attitude of the tool with respect to a workpiece, and is characterized by comprising a determination step of determining whether the attitude of the first robot is in an attitude change limit near area, which is an area close to the limit of the change range of the attitude of the first robot, or in an attitude change limit far area, which is an area farther from the limit than the attitude change limit near area, and a control step of controlling the first robot and the second robot to change the relative attitude based on the determination result of the determination step.

[0103] <13> A program according to one embodiment of the present disclosure is a program for controlling a robot control system including a first robot to which a tool is attached and a second robot capable of changing the relative attitude of the tool with respect to a workpiece, and is characterized in that it causes a computer to function as a control device including a determination means for determining whether the attitude of the first robot is in an attitude change limit near area, which is an area close to the limit of the change range of the attitude of the first robot, or in an attitude change limit far area, which is an area farther from the limit than the attitude change limit near area, and a control means for controlling the first robot and the second robot to change the relative attitude based on the determination result of the determination means. [Explanation of symbols]

[0104] 1. Robot Control System 10 First Robot 11 Base 12 Arm section 12a First Arm 12b Second Arm 13 End plate 13a Center point 20 Second Robot 21 Arm 30 Control device 31 Communications Department 32 Input section 33 Output section 34 Storage section 34a Movable range information storage unit 34b control information storage unit 35 Control Unit 35a Judgment means 35b Means of designation 35c Reception method 35d Identification means 35e Selection method 35f Control means 90 Information processing equipment 91 processors 92 Main memory 93 Communication Interface 94 Auxiliary storage device 95 Input / Output Interface 96 Internal Bus A1 Region near the limit of attitude change A2 Posture change limit remote area C Rotation center point N Network S1 Designated step S2 Reception step S3 Identification Step S4 Selection Step S5 Judgment step S6 Control Step Sf1 1st axis Sf2 2nd axis T Tool double work

Claims

1. a first robot to which a tool is attached; a second robot capable of changing the relative orientation of the tool with respect to the workpiece; A robot control system comprising: a determination means for determining whether the posture of the first robot is in a posture change limit near region, which is a region close to the limit of a change range of the posture of the first robot, or in a posture change limit far region, which is a region farther from the limit than the posture change limit near region; a control means for controlling the first robot and the second robot so as to change the relative posture based on the determination result of the determination means; A robot control system comprising:

2. the first robot is attached to the second robot; when the determination means determines that the posture of the first robot is in the posture change limit vicinity region, the control means controls the second robot so that the posture of the tool changes in a direction in which the posture of the first robot is changing from a neutral posture.

2. The robot control system according to claim 1.

3. the second robot holds the workpiece, When the determination means determines that the posture of the first robot is in the posture change limit vicinity region, the control means controls the second robot so that the posture of the workpiece changes in a direction opposite to a direction in which the posture of the first robot is changing from a neutral posture.

2. The robot control system according to claim 1.

4. means of designation; Further provided with the relative orientation includes a first relative orientation that is a relative orientation of the first robot about a first axis and a second relative orientation that is a relative orientation of the first robot about a second axis, the control means controls the first robot and the second robot so as to change the first relative attitude based on the determination result of the determination means when the first relative attitude is designated by the designation means, and controls the first robot and the second robot so as to change the second relative attitude based on the determination result of the determination means when the second relative attitude is designated by the designation means.

2. The robot control system according to claim 1.

5. the first robot is a parallel link robot, the attitude change limit remote region becomes narrower as the distance between the center point of the end plate of the parallel link robot and the rotation center point of the parallel link robot increases; 5. The robot control system according to claim 1, wherein the control unit is a controller.

6. the control means controls the second robot to change the relative posture when the posture of the first robot is in the posture change limit near region, and controls the first robot to change the relative posture when the posture of the first robot is in the posture change limit far region.

5. The robot control system according to claim 1, wherein the control unit is a controller.

7. a receiving means for receiving an instruction to set the posture of the second robot to a neutral posture; Further provided with the control means controls the second robot to bring the posture of the second robot into a neutral posture when the reception means receives the instruction.

5. The robot control system according to claim 1, wherein the control unit is a controller.

8. the speed at which the posture of the second robot is changed by the control means is slower than the speed at which the posture of the first robot is changed by the control means; 5. The robot control system according to claim 1, wherein the control unit is a controller.

9. the control means controls the first robot and the second robot in this order when changing the posture of the first robot from the posture change limit near region to the posture change limit far region.

5. The robot control system according to claim 1, wherein the control unit is a controller.

10. a determination unit that determines whether or not to execute a control process by the control unit; Further provided with The control means executes the control process when the specification means specifies that the control process should be executed, and does not execute the control process when the specification means specifies that the control process should not be executed.

5. The robot control system according to claim 1, wherein the control unit is a controller.

11. a selection means for selecting either the first control mode or the second control mode; Further provided with When the posture is in the posture change limit vicinity region, if the selection means selects a first control mode, the control means controls the second robot to change the relative posture while maintaining the posture, and if the selection means selects a second control mode, the control means controls the second robot to set the posture to a neutral posture and change the relative posture.

5. The robot control system according to claim 1, wherein the control unit is a controller.

12. a first robot to which a tool is attached; a second robot capable of changing the relative orientation of the tool with respect to the workpiece; A control method for a robot control system comprising: a determining step of determining whether the posture of the first robot is in a posture change limit near region, which is a region close to the limit of a change range of the posture of the first robot, or in a posture change limit far region, which is a region farther from the limit than the posture change limit near region; a control step of controlling the first robot and the second robot so as to change the relative posture based on the determination result of the determination step; A robot control method comprising:

13. a first robot to which a tool is attached; a second robot capable of changing the relative orientation of the tool with respect to the workpiece; A program for controlling a robot control system comprising: Computer, a determination means for determining whether the posture of the first robot is in a posture change limit near region, which is a region close to the limit of a change range of the posture of the first robot, or in a posture change limit far region, which is a region farther from the limit than the posture change limit near region; a control means for controlling the first robot and the second robot so as to change the relative posture based on the determination result of the determination means; and functioning as a control device comprising: A program characterized by:

Images