Force control parameter setting assistance method and force control parameter setting assistance system

Abstract

Provided are a force control parameter setting assistance method and a force control parameter setting assistance system, by which force control parameters can be properly set by a simple method. A force control parameter setting assistance method for assisting in setting force control parameters for force control of a robot arm to which a polishing tool is attached at a front end to perform polishing work on an object, the force control parameter setting assistance method including: a first step of acquiring work information related to the polishing work; a second step of selecting and reading information of the force control parameters corresponding to the work information acquired in the first step from a storage unit in which information of a plurality of force control parameters is stored; and a third step of displaying the information of the force control parameters read in the second step on a display unit.

Description

TECHNICAL FIELD

[0001] The present application relates to a force control parameter setting assistance method and a force control parameter setting assistance system. BACKGROUND

[0002] For example, an automatic polishing apparatus that polishes by moving a polishing tool along a path programmed in advance is disclosed in Patent Literature 1. In this automatic polishing apparatus, the polishing force applied to the polishing tool is controlled based on the action of moving the tool while keeping the polishing force constant by a polishing force measuring device, that is, an action using force control. Thus, it is possible to perform the polishing work while keeping the polishing force as much as possible at a desired value.

[0003] Patent Literature 1: Japanese Patent Application Laid-Open No. 2005-81477

[0004] When force control is performed, it is necessary to set the force control parameter to an appropriate value. However, this setting adopts a method of repeating the work while changing the force control parameter to find a force control parameter suitable for the polishing work, and it is difficult for a person who is not skilled to adjust it. SUMMARY

[0005] The force control parameter setting assistance method of the present application is characterized by assisting in setting a force control parameter for force control when a robot arm to which a polishing tool is attached at a front end is controlled by the force control to perform a polishing work on an object, the force control parameter setting assistance method having: a first step of acquiring work information related to the polishing work; a second step of selecting and reading information of the force control parameter corresponding to the work information acquired in the first step from a storage section in which information of a plurality of the force control parameters is stored; and a third step of displaying the information of the force control parameter read in the second step at a display section.

[0006] The force control parameter setting assistance system of the present application is characterized by including a setting assistance section that assists in setting a force control parameter for force control when a robot arm to which a polishing tool is attached at a front end is controlled by the force control to perform a polishing work on an object, the setting assistance section having: an acquisition section that acquires work information related to the polishing work; a reading section that selects and reads information of the force control parameter corresponding to the work information acquired by the acquisition section from a storage section in which information of a plurality of the force control parameters is stored; and a display control section that displays the information of the force control parameter read by the reading section at a display section. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 A diagram showing the overall configuration of a robot system that executes the force control parameter setting assistance method of the present application.

[0008] Figure 2 For Figure 1 a block diagram of the robot system shown.

[0009] Figure 3 For Figure 2 a block diagram of the setting assistance section provided in the robot system shown.

[0010] Figure 4 For an example of a screen displayed on the display section.

[0011] Figure 5 For an example of a screen displayed on the display section.

[0012] Figure 6 For an example of a screen displayed on the display section.

[0013] Figure 7 For an example of a screen displayed on the display section.

[0014] Figure 8 For an example of a screen displayed on the display section.

[0015] Figure 9 For an example of a screen displayed on the display section.

[0016] Figure 10 For an example of a screen displayed on the display section.

[0017] Figure 11 For an example of a screen displayed on the display section.

[0018] Figure 12 For an example of a screen displayed on the display section.

[0019] Figure 13 For an example of a screen displayed on the display section.

[0020] Figure 14 For an example of a screen displayed on the display section.

[0021] Figure 15 For a flowchart of the control action performed by the robot system shown. Figure 1

[0022] Figure 16 For a block diagram for explaining the robot system in a hardware-centered manner.

[0023] Figure 17 For a block diagram of a modification example 1 in a hardware-centered manner of the robot system.

[0024] ​Figure 18 A block diagram of a modification example 2 that is a hardware-centered example of the robot system.

[0025] Explanation of reference numerals

[0026] 1: robot; 3: control device; 3A: target position setting section; 3B: drive control section; 3C: storage section; 3D: setting assistance section; 4: teaching device; 10: robot arm; 10A: force control parameter setting assistance system; 11: base; 12: first arm; 13: second arm; 14: third arm; 15: fourth arm; 16: fifth arm; 17: sixth arm; 18: relay cable; 19: force detection section; 20: end effector; 30: position control section; 31: coordinate conversion section; 31D: acquisition section; 32: coordinate conversion section; 32D: reading section; 33: correction section; 33D: display control section; 34: force control section; 35: command integration section; 41: display section; 61: controller; 62: computer; 63: computer; 64: cloud; 65: network; 66: computer; 100: robot system; 100A: robot system; 100B: robot system; 100C: robot system; 171: joint; 172: joint; 173: joint; 174: joint; 175: joint; 176: joint; 351: execution section; CP: control point; E1: encoder; E2: encoder; E3: encoder; E4: encoder; E5: encoder; E6: encoder; D1: input screen; D2: input screen; D3: input screen; D4: input screen; D5: input screen; D6: input screen; D7: input screen; D8: input screen; D9: input screen; D10: input result display screen; D11: display screen; M1: motor; M2: motor; M3: motor; M4: motor; M5: motor; M6: motor; TCP: tool center point; W1: workpiece. DETAILED DESCRIPTION

[0027] Embodiment

[0028] Figure 1 A diagram for showing the overall configuration of a robot system that executes the force control parameter setting assistance method of the present application. Figure 2 For Figure 1 A block diagram of a robot system. Figure 3 For Figure 2 A block diagram of a setting assistance section possessed by a robot system. Figures 4 to 14 A diagram for showing an example of a screen displayed on a display section. Figure 15 For Figure 1 A flowchart for showing a control action executed by a robot system.

[0029] The force control parameter setting auxiliary method and force control parameter setting auxiliary system of the present invention will be described in detail below based on the preferred embodiments shown in the accompanying drawings. It should be noted that, for ease of explanation, the following will also... Figure 1 In this context, the +Z axis direction, i.e., the upper side, is referred to as "up," and the -Z axis direction, i.e., the lower side, is referred to as "down." Additionally, regarding robotic arms, [the text continues with further details about the robotic arm and its role in robotic arm development]. Figure 1 The base side is called the "base end," and its opposite side, the end effector side, is called the "front end." Additionally, the... Figure 1 The Z-axis direction, i.e., the up-down direction, is set as the "vertical direction," and the X-axis direction and Y-axis direction, i.e., the left-right direction, are set as the "horizontal direction."

[0030] like Figure 1 As shown, the robot system 100 includes a robot 1, a control device 3 for controlling the robot 1, and a teaching device 4, and executes the force control parameter setting assistance method of the present invention. Furthermore, a force control parameter setting assistance system 10A is built into the control device 3, and the force control parameter setting assistance method of the present invention is executed through the force control parameter setting assistance system 10A.

[0031] First, let's explain robot 1.

[0032] Figure 1 The robot 1 shown in this embodiment is a single-arm, six-axis vertical joint robot, having a base 11 and a robotic arm 10. Additionally, an end effector 20 can be mounted on the front end of the robotic arm 10. The end effector 20 may or may not be a component of the robot 1.

[0033] It should be noted that robot 1 is not limited to the configuration shown in the figure; for example, it could also be a dual-armed multi-joint robot. Additionally, robot 1 could also be a horizontal multi-joint robot.

[0034] The base 11 is a support that can be driven from below to support the robotic arm 10, for example, fixed to the floor in a factory. The base 11 of the robot 1 is electrically connected to the control device 3 via a relay cable 18. It should be noted that the connection between the robot 1 and the control device 3 is not limited to... Figure 2 The configuration shown is based on a wired connection, but it could also be based on a wireless connection.

[0035] In this embodiment, the robotic arm 10 has a first arm 12, a second arm 13, a third arm 14, a fourth arm 15, a fifth arm 16, and a sixth arm 17, which are connected sequentially from the base 11. It should be noted that the number of arms in the robotic arm 10 is not limited to six; for example, it can have one, two, three, four, five, or more than seven arms. Furthermore, the overall length and size of each arm are not particularly limited and can be appropriately set.

[0036] The base 11 is connected to the first arm 12 via a joint 171. Also, the first arm 12 is able to rotate with respect to the base 11 about a first rotation axis parallel to the vertical direction as a center of rotation. The first rotation axis coincides with the normal line of the floor on which the base 11 is fixed.

[0037] The first arm 12 and the second arm 13 are connected via a joint 172. Also, the second arm 13 is able to rotate with respect to the first arm 12 about a second rotation axis parallel to the horizontal direction as a center of rotation. The second rotation axis is parallel to an axis orthogonal to the first rotation axis.

[0038] The second arm 13 and the third arm 14 are connected via a joint 173. Also, the third arm 14 is able to rotate with respect to the second arm 13 about a third rotation axis parallel to the horizontal direction as a center of rotation. The third rotation axis is parallel to the second rotation axis.

[0039] The third arm 14 and the fourth arm 15 are connected via a joint 174. Also, the fourth arm 15 is able to rotate with respect to the third arm 14 about a fourth rotation axis parallel to the central axis direction of the third arm 14 as a center of rotation. The fourth rotation axis is orthogonal to the third rotation axis.

[0040] The fourth arm 15 and the fifth arm 16 are connected via a joint 175. Also, the fifth arm 16 is able to rotate with respect to the fourth arm 15 about a fifth rotation axis as a center of rotation. The fifth rotation axis is orthogonal to the fourth rotation axis.

[0041] The fifth arm 16 and the sixth arm 17 are connected via a joint 176. Also, the sixth arm 17 is able to rotate with respect to the fifth arm 16 about a sixth rotation axis as a center of rotation. The sixth rotation axis is orthogonal to the fifth rotation axis.

[0042] In addition, the sixth arm 17 becomes the robot front end portion of the robot arm 10 located at the most front end side. This sixth arm 17 is able to rotate together with the end effector 20 by the driving of the robot arm 10.

[0043] The robot 1 is provided with motors M1, M2, M3, M4, M5, and M6 as driving portions, and encoders E1, E2, E3, E4, E5, and E6. The motor M1 is built in the joint 171 and relatively rotates the base 11 and the first arm 12. The motor M2 is built in the joint 172 and relatively rotates the first arm 12 and the second arm 13. The motor M3 is built in the joint 173 and relatively rotates the second arm 13 and the third arm 14. The motor M4 is built in the joint 174 and relatively rotates the third arm 14 and the fourth arm 15. The motor M5 is built in the joint 175 and relatively rotates the fourth arm 15 and the fifth arm 16. The motor M6 is built in the joint 176 and relatively rotates the fifth arm 16 and the sixth arm 17.

[0044] In addition, an encoder E1 is built in the joint 171 and detects the position of the motor M1. An encoder E2 is built in the joint 172 and detects the position of the motor M2. An encoder E3 is built in the joint 173 and detects the position of the motor M3. An encoder E4 is built in the joint 174 and detects the position of the motor M4. An encoder E5 is built in the joint 175 and detects the position of the motor M5. An encoder E6 is built in the joint 176 and detects the position of the motor M6.

[0045] The encoders E1 to E6 are electrically connected to the control device 3 and transmit the position information, i.e., the rotational amount of the motors M1 to M6 to the control device 3 as an electric signal. Then, the control device 3 drives the motors M1 to M6 based on the information via a motor driver not shown. That is, the control of the robot arm 10 is the control of the motors M1 to M6.

[0046] In addition, a control point CP is provided at the front end of the robot arm 10. The control point CP is a point that becomes a reference when the robot arm 10 is controlled. In the robot system 100, the position of the control point CP is grasped in the robot coordinate system, and the robot arm 10 is driven to move the control point CP to a desired position.

[0047] In addition, in the robot 1, a force detection unit 19 that detects force is detachably provided to the robot arm 10. Also, the robot arm 10 is capable of being driven in a state in which the force detection unit 19 is provided. The force detection unit 19 is a six-axis force sensor in the present embodiment. The force detection unit 19 detects the magnitude of force in three detection axes orthogonal to each other and the magnitude of torque around the three detection axes. That is, the force components in each of the X-axis, Y-axis, and Z-axis orthogonal to each other, the force component in the Tx direction around the X-axis, the force component in the Ty direction around the Y-axis, and the force component in the Tz direction around the Z-axis are detected. Note that, in the present embodiment, the Z-axis direction becomes the vertical direction. In addition, the force components in each axis can be referred to as "translational force components", and the force components around each axis can be referred to as "rotational force components". In addition, the force detection unit 19 is not limited to a six-axis force sensor, and can be a sensor of another configuration.

[0048] In the present embodiment, the force detection unit 19 is provided to the sixth arm 17. Note that, as a place to provide the force detection unit 19, it is not limited to the sixth arm 17, i.e., the arm located at the most front end side, and can be, for example, another arm, between adjacent arms, below the base 11, or can be provided to all of the joints, respectively.

[0049] The end effector 20 can be detachably attached to the force detecting portion 19. The end effector 20 is constituted by a tool for polishing in the present embodiment. The end effector 20 has a grinding wheel at the front end, and polishes the workpiece W1 by contacting the workpiece W1 while rotating the grinding wheel. Note that, in the present embodiment, the grinding wheel is used as the tool for polishing, but it is not limited thereto, and can be a tool for polishing obtained by attaching abrasive grains to paper, cloth, or a film, or a sponge.

[0050] In addition, a tool center point TCP is set at an arbitrary position of the front end of the end effector 20, preferably at the front end of the grinding wheel, in the robot coordinate system. As described above, in the robot system 100, the position of the control point CP is grasped in the robot coordinate system, and the robot arm 10 is driven to move the control point CP to a desired position. In addition, by grasping the kind of the end effector 20, particularly the length, in advance, the offset amount of the tool center point TCP from the control point CP can be grasped. Thus, the position of the tool center point TCP can be grasped in the robot coordinate system. Therefore, the tool center point TCP can be set as a reference for control.

[0051] The workpiece W1 is an object to be polished by the end effector 20. The area of the surface of the workpiece W1 to be polished is a polishing area. As the workpiece W1, a connector of an electronic device, a plastic package, a metal package, or the like can be given.

[0052] Next, the control device 3 and the teaching device 4 will be described.

[0053] The control device 3 is disposed separately from the robot 1, and can be constituted by a computer or the like in which a CPU (Central Processing Unit) as an example of a processor is built in. The control device 3 can also be built in the base 11 of the robot 1.

[0054] The control device 3 is communicably connected to the robot 1 through the relay cable 18. In addition, the control device 3 is connected to the teaching device 4 through a cable, or can be communicably connected wirelessly. The teaching device 4 can be a dedicated computer, or a general-purpose computer in which a program for teaching the robot 1 is installed. For example, a teaching panel or the like as a dedicated device for teaching the robot 1 can be used instead of the teaching device 4. Also, the control device 3 and the teaching device 4 can have respective housings, or can be integrally constituted.

[0055] In addition, the teaching device 4 can be provided with a program for generating the target position posture S t and the target force f StA program for the argument is executed and the generated execution program is loaded to the control device 3. The teaching device 4 is provided with a display, a processor, a RAM, a ROM, and these hardware resources cooperate with a teaching program to generate an execution program.

[0056] As shown in Figure 2 , the control device 3 is a computer in which a control program for controlling the robot 1 is installed. The control device 3 is provided with a processor, a RAM not shown, a ROM, and controls the robot 1 by cooperation of these hardware resources and a program.

[0057] Further, as shown in Figure 2 , the control device 3 has a target position setting section 3A, a drive control section 3B, a storage section 3C, and a setting assistance section 3D. The storage section 3C is constituted by, for example, a volatile memory such as a RAM (Random Access Memory), a non-volatile memory such as a ROM (Read Only Memory), a detachable external storage device, and the like. In the storage section 3C, a program and the like for executing the force control parameter setting assistance method of the present application, an action program for operating the robot 1 are stored.

[0058] Note that, in the present embodiment, the setting assistance section 3D is built in the control device 3, but in the present application, it is not limited thereto, and can be built in the teaching device 4.

[0059] The target position setting section 3A sets a target position posture S t and an action path for executing a predetermined work on the workpiece W1. The target position setting section 3A sets the target position posture S t and the action path based on teaching information and the like input from the teaching device 4.

[0060] The drive control section 3B is a control section that controls driving of the robot 1, and has a position control section 30, a coordinate conversion section 31, a coordinate conversion section 32, a correction section 33, a force control section 34, and an instruction integration section 35.

[0061] The position control section 30 generates a position command signal, i.e., a position command value, which controls the position of the tool center point TCP of the robot 1, in accordance with the target position specified by a command made in advance.

[0062] Here, the control device 3 can control the action of the robot 1 by force control and the like. The "force control" is control of the action of the robot 1 that changes the position of the end effector 20, i.e., the position of the tool center point TCP, the posture of the first arm 12 to the sixth arm 17, based on the detection result of the force detection section 19.

[0063] The force control includes, for example, force trigger control and impedance control. In the force trigger control, force detection is performed by the force detection section 19, and the robot arm 10 is caused to perform a movement or a posture change before a predetermined force is detected by the force detection section 19.

[0064] The impedance control includes mimic control. First, if explained simply, in the impedance control, the robot arm 10 is controlled in such a manner that a force applied to the tip end section of the robot arm 10 is maintained as a predetermined force, that is, a force in a predetermined direction detected by the force detection section 19 is maintained as a target force f St as much as possible. Thereby, for example, if the robot arm 10 is subjected to the impedance control, the robot arm 10 performs a movement that mimics an external force applied from an object or an operator in the predetermined direction. Note that the target force f St also includes 0. For example, as one of settings in the case of the mimic movement, the target value can be set to "0". Note that the target force f St may be set to a value other than 0. The target force f St may be appropriately set by an operator.

[0065] The storage section 3C stores a correspondence relation between a combination of the rotation angles of the motors M1 to M6 and a position of the tool center point TCP in the robot coordinate system. In addition, the control device 3 stores at least one of the target position posture S t and the target force f St to the storage section 3C on the basis of a command of a process of a work performed by the robot 1. The command of the process of the work performed by the robot 1 is set with the target position posture S t and the target force f St as arguments, that is, parameters.

[0066] The drive control section 3B controls the first arm 12 to the sixth arm 17 so that the set target position posture S t and the target force f St agree with the tool center point TCP. The target force f St is a detected force and torque of the force detection section 19 that should be achieved by the movement of the first arm 12 to the sixth arm 17. Here, the character "S" is set to represent any one of directions (X, Y, Z) of axes of the robot coordinate system. In addition, S is set to also represent a position in the S direction. For example, in the case of S = X, the X-direction component of the target position set in accordance with the robot coordinate system is S t = X t , and the X-direction component of the target force is f St = f Xt .

[0067] Furthermore, if the rotation angles of motors M1 to M6 are obtained through the drive control unit 3B, then Figure 3 The coordinate transformation unit 31 shown converts the rotation angle into the position and orientation S (X, Y, Z, U, V, W) of the tool center point TCP in the robot coordinate system based on the correspondence. Then, the coordinate transformation unit 32 determines the actual force f acting on the force detection unit 19 in the robot coordinate system based on the position and orientation S of the tool center point TCP and the detection value of the force detection unit 19. S .

[0068] Unlike the tool center point TCP, the force f S The point of application is defined as the force detection origin. The force detection origin corresponds to the point where the force detection unit 19 detects the force. It should be noted that the control device 3 stores the correspondence between the directions of the detection axis of the force detection unit 19 and the sensor coordinate system according to the position and orientation S of the tool center point TCP in the robot coordinate system. Therefore, the control device 3 can determine the force f in the robot coordinate system based on the correspondence with the position and orientation S of the tool center point TCP in the robot coordinate system. S Furthermore, the torque acting on robot 1 can be determined based on the force f. S The torque is calculated from the distance from the contact point to the force detection unit 19 and determined as a rotational force component. It should be noted that when the end effector 20 contacts the workpiece W1 to perform the operation, the contact point can be considered as the tool center point TCP.

[0069] Correction unit 33 affects the force f S Gravity compensation is performed. Gravity compensation is achieved by adjusting the force f. S After removing the force and torque components caused by gravity, the gravity-compensated force f can be considered. S It is considered as a force other than gravity acting on the robotic arm 10 or the end effector 20.

[0070] In addition, the correction unit 33 affects the force f S Inertia compensation is performed. Inertia compensation is the process of adjusting the force f. S After removing the force and torque components caused by inertial forces, the inertial compensated force f can be considered. S Forces other than the inertial forces acting on the robotic arm 10 or the end effector 20 are considered as forces.

[0071] The force control section 34 performs impedance control. The impedance control is active impedance control that virtually realizes mechanical impedance by the motors M1 to M6. The control device 3 performs such impedance control when directly teaching the process in which the end effector 20 receives a contact state of force from the workpiece W1 as an object in the embedding work, the screwing work, the polishing work, and the like of the workpiece W1. Note that even outside such a process, for example, when a person contacts the robot 1, by performing impedance control, it is possible to improve safety.

[0072] In the impedance control, the target force f St is substituted into a motion equation described later to derive the rotation angles of the motors M1 to M6. The signals of the motors M1 to M6 controlled by the control device 3 are PWM (Pulse Width Modulation) modulated signals.

[0073] In addition, the control device 3, in a process in which the end effector 20 is in a non-contact state not subjected to an external force, derives the rotation angles of the motors M1 to M6 from the target position and posture S t The rotation angles derived by the linear operation control the motors M1 to M6. The target position and posture S t The mode in which the rotation angles derived by the linear operation control the motors M1 to M6 is called a position control mode.

[0074] The control device 3 determines the force origin correction amount AS by substituting the target force f St and the acting force f S into a motion equation of the impedance control. The force origin correction amount AS refers to the magnitude of the position and posture S in which the tool center point TCP should move in order to eliminate the force deviation Af St from the target force f S (t) in the case where the tool center point TCP is subjected to mechanical impedance. The following equation (1) is the motion equation of the impedance control.

[0075]

[0076] The left side of the equation (1) is composed of a first term obtained by multiplying the second-order differential value of the position and posture S of the tool center point TCP by a virtual mass coefficient m (hereinafter referred to as "mass coefficient m"), a second term obtained by multiplying the differential value of the position and posture S of the tool center point TCP by a virtual viscous coefficient d (hereinafter referred to as "viscous coefficient d"), and a third term obtained by multiplying the position and posture S of the tool center point TCP by a virtual elastic coefficient k (hereinafter referred to as "elastic coefficient k"). The right side of the equation (1) is composed of a force deviation Af St obtained by subtracting the actual force f from the target force f S(t) Configuration. The differential in formula (1) refers to a time-based differential. In the process performed by the robot 1, there are cases where a certain value is set as the target force f St , and cases where a function of time is set as the target force f St .

[0077] The mass coefficient m refers to the mass that the tool center point TCP virtually has, the viscosity coefficient d refers to the viscous resistance that the tool center point TCP virtually receives, and the spring constant k refers to the elastic force that the tool center point TCP virtually receives.

[0078] As the value of the mass coefficient m becomes larger, the acceleration of the motion becomes smaller, and as the value of the mass coefficient m becomes smaller, the acceleration of the motion becomes larger. As the value of the viscosity coefficient d becomes larger, the speed of the motion becomes slower, and as the value of the viscosity coefficient d becomes smaller, the speed of the motion becomes faster. As the value of the spring constant k becomes larger, the elasticity becomes larger, and as the value of the spring constant k becomes smaller, the elasticity becomes smaller.

[0079] These mass coefficient m, viscosity coefficient d, and spring constant k can be set to different values according to the direction, or can be set to a common value regardless of the direction. In addition, the mass coefficient m, viscosity coefficient d, and spring constant k can be appropriately set by the operator before the work.

[0080] Such mass coefficient m, viscosity coefficient d, and spring constant k are force control parameters. The force control parameters are values that are set before the actual work of the robot arm 10 is performed. In addition to the mass coefficient m, viscosity coefficient d, and spring constant k, the force control parameters include the aforementioned target force and the like.

[0081] Thus, in the robot system 100, in performing force control, a correction amount is calculated from the detection value of the force detection section 19, the force control parameters set in advance, and the target force set in advance. This correction amount is the aforementioned force-origin correction amount ΔS, and is the difference between the position to which the tool center point TCP is moved and the position to which the tool center point TCP should be moved in response to the external force.

[0082] Then, the command integration section 35 adds the force-origin correction amount ΔS to the position command value P generated by the position control section 30. By performing this calculation at all times, the command integration section 35 calculates a new position command value P' from the position command value P for moving to the position to which the external force is applied.

[0083] Then, the coordinate conversion section 31 converts this new position command value P' into a robot coordinate, and the execution section 351 performs execution so that the tool center point TCP is moved to the position to which the force-origin correction amount ΔS is added, and responds to the external force, and thus the load applied to the object in contact with the robot 1 can be alleviated.

[0084] According to such a drive control section 3B, it is possible to perform force control while pressing the end effector 20 against the workpiece Wl, and it is possible to perform good polishing work while applying a desired pressure.

[0085] As shown in Figures 4 to 14 , the setting assistance section 3D has an acquisition section 31D, a reading section 32D, and a display control section 33D.

[0086] The acquisition section 31D acquires work information related to polishing work input by the operator, for example, via the teaching device 4. Here, the work information includes information related to the workpiece Wl as an object and information related to a polishing tool.

[0087] The information related to the workpiece Wl includes information related to the shape of a polishing region of the workpiece Wl, the size of the polishing region of the workpiece Wl, the material of the polishing region, the surface roughness of the polishing region before polishing, and the target surface roughness of the polishing region after polishing.

[0088] Note that the information related to the workpiece Wl can include at least one of the above-mentioned listed information.

[0089] The information related to the polishing tool includes the kind of the polishing tool and the operating condition of the polishing tool.

[0090] Specifically, the information related to the polishing tool includes information related to the material of abrasive grains of a grinding wheel, information related to the size of the abrasive grains, and information related to the rotational speed of the grinding wheel.

[0091] Note that the information related to the polishing tool can include at least one of the above-mentioned listed information.

[0092] Such work information is input by the operator using Figure 4 the input screen shown. Regarding this part, detailed description will be given later.

[0093] The reading section 32D selects and reads information of a force control parameter corresponding to the work information acquired by the acquisition section 31D from the storage section 3C in which information of a plurality of force control parameters is stored. That is, the reading section 32D selects and reads information of a force control parameter suitable for the acquired work information from a database stored in the storage section 3C. Regarding the selection method of the information of the force control parameter suitable for the work information, detailed description will be given later.

[0094] The display control section 33D generates an instruction signal for displaying the information of the force control parameter read by the reading section 32D on the display section 41.

[0095] Next, an example of the input screen when inputting work information will be described. The input screen is the screen displayed on the display unit 41 of the teaching pendant 4. However, it is not limited to this configuration and may also be displayed on other display units.

[0096] As an input screen, list Figure 5 The input screen D1 shown Figure 6 The input screen D2 shown Figure 7 The input screen D3 shown Figure 8 The input screen shown is D4. Figure 9 The input screen shown is D5. Figure 10 The input screen shown is D6. Figure 11 The input screen shown is D7. Figure 12 The input screen D8 shown is Figure 4 The input screen D9 is shown. In this embodiment, input screens D2 to D9 are displayed appropriately according to the content set by input screen D1.

[0097] exist Figure 5 In the input screen D1 shown, the priority order of job information categories can be set by entering categories in the input section on the left side of the diagram. The diagram displays six categories: "Material," "Backing," "Abrasive," "Grain Size," "Area," and "Task." By entering these categories sequentially, as shown in the display section on the right side of the diagram, the priority order is set. Categories with higher priority settings will be retrieved first when considering the read force control parameters, which will be discussed later.

[0098] "Material" refers to the material of workpiece W1, specifically the material of the grinding area. "Backing" refers to the base material of the grinding tool, i.e., the grinding substrate. "Abrasive" refers to the abrasive used in the grinding operation. "Grain Size" refers to the size of the abrasive grains on the grinding wheel. "Area" refers to the shape of the grinding area on workpiece W1. "Task" refers to the degree of finishing after grinding. Through this input screen D1, priority can be set according to category.

[0099] Figure 6The input screen D2 shown is a screen for inputting the material of the workpiece Wl. Specifically, the material of the workpiece Wl is selected by selecting the material of the workpiece Wl from the area displayed as "Material List", and the material of the workpiece Wl is selected. In the illustrated configuration, one is selected from "POM", "ABS", "Acrylic", "PVC", "Bakelite", "SS400", "S45C", "SPCC", "SUS", and "Titanium". With such an input screen D2, information related to the material of the workpiece Wl can be input.

[0100] Figure 7 The input screen D3 shown is a screen for inputting the kind of the polishing base material of the polishing tool. Specifically, the kind of the polishing base material is selected by selecting the material of the workpiece Wl from the area displayed as "Backing List", and the kind of the polishing base material is selected. In the illustrated configuration, one is selected from "Paper", "Cloth", "Film", "Net", "Form", and "Buff". With such an input screen D3, information related to the kind of the polishing base material can be input.

[0101] Figures 8 to 10 The input screen D4 shown is a screen for inputting the kind of the abrasive grain of the grinding wheel. Specifically, one is selected from "A", "WA", "PA", "HA", "AE", "AZ(25)", "AZ(40)", "C", "GC", "D", "SD", "SDC", "CBN", and "CBNC". With such an input screen D4, information related to the kind of the abrasive grain of the grinding wheel can be input.

[0102] Figure 8 The input screens D5 to D7 shown are screens for inputting the size of the abrasive grain of the grinding wheel. Figure 9 The input screen D5 shown is a state in which "Grinding Wheel" is selected, Figure 10 The input screen D6 shown is a state in which "Sand Paper" is selected, Figure 8 The input screen D7 shown is a state in which "Diamond / CBN" is selected.

[0103] Figure 9The input screen D5 shown is a screen for inputting the grit size under "Grinding Wheel". Specifically, one is selected from the values of "F4", "F5", "F6", "F7", "F8", "F10", "F12", "F14", "F16", "F20", "F22", "F24", "F30", "F36", "F40", and the following. With such an input screen D5, information relating to the grit size under "Grinding Wheel" can be selected.

[0104] Figure 10 The input screen D6 shown is a screen for inputting the grit size under "Sand Paper". Specifically, one is selected from the values of "P180", "P220", "P240", "P280", "P320", "P360", "P400", "P500", "P600", "P800", "P1000", "P1200", "P1500(S)", "P2000(S)", "P2500(S)", and the following. With such an input screen D6, information relating to the grit size under "Sand Paper" can be inputted.

[0105] Figure 11 The input screen D7 shown is a screen for inputting the grit size under "Diamond / CBN". Specifically, one is selected from the values of "30 / 40(#30)", "40 / 50(#40)", "50 / 60(#50)", "60 / 80(#60)", "80 / 100(#80)", "100 / 120(#100)", "120 / 140(#120)", "140 / 170(#140)", "170 / 200(#170)", "200 / 230(#200)", "230 / 270(#230)", "270 / 325(#270)", "325 / 400(#325)", "#500", "#600", and the following. With such an input screen D7, information relating to the grit size in "Diamond / CBN" can be inputted.

[0106] Figure 12 The input screen D8 shown is a screen for inputting the shape of the polishing area of the workpiece Wl. Specifically, one is selected from "Flat Surface", "Curved Surface", "Edge". With such an input screen D8, information relating to the shape of the polishing area of the workpiece Wl can be selected.

[0107] Figure 13The input screen D9 shown is a screen for inputting the surface roughness after polishing. Specifically, one is selected from "Deburring", "Cutter Mark Removal", "Parting line Removal", "Hairline Finish", and the like. With such an input screen D9, information related to the surface roughness of the workpiece Wl after polishing can be selected.

[0108] With such input screens Dl to D9, the job information can be input.

[0109] Then, in Figure 14 The inputted job information is displayed in the input result display screen DlO shown. Next, in the input result display screen DlO, upon pressing the "Finish" button, the reading section 32D selects and reads information of the force control parameter appropriate for the job information acquired from the database stored in the storage section 3C.

[0110] The pair information associating the job information and the information of the force control parameter appropriate thereto is stored in the storage section 3C. The pair information is stored in the storage section 3C in accordance with the combination of different categories of the job information. The reading section 32D searches for job information coincident with the acquired job information, or which can be considered to be the closest to the acquired job information, from the storage section 3C, and reads the information of the force control parameter associated with the job information.

[0111] Then, the display control section 33D transmits an instruction signal to the teaching device 4 so that the display section 41 displays the information of the force control parameter read by the reading section 32D, for example, as Figure 15 the display screen Dl l shown. Thereby, the display section 41 can display the force control parameter appropriate for the polishing job to be performed next. Therefore, the operator can directly set the displayed force control parameter, or can set it after making a slight adjustment.

[0112] Here, in the past, the setting of the force control parameter has been performed by repeating the job while changing the force control parameter to find the force control parameter appropriate for the polishing job, and the adjustment has been difficult if not by a skilled person. In contrast, according to the present application, the job information related to the polishing job is acquired, the information of the force control parameter corresponding to the acquired job information is selected and read, and is displayed. With such a configuration, the troublesome job of the past can be omitted, and even if not by a skilled person, an appropriate force control parameter can be set.

[0113] Thus, the force control parameter setting assistance system 10A of the present application includes a setting assistance section 3D that assists in setting a force control parameter used for force control when a robot arm 10 equipped with a tool for polishing at a front end is controlled by force control to perform a polishing operation on a workpiece W1 as an object. The setting assistance section 3D includes an acquisition section 31D that acquires operation information related to the polishing operation, a reading section 32D that selects and reads information of a force control parameter corresponding to the operation information acquired by the acquisition section 31D from a storage section 3C in which information of a plurality of force control parameters is stored, and a display control section 33D that displays the information of the force control parameter read by the reading section 32D on a display section 41. Thus, a troublesome setting operation as in the past can be omitted, and an appropriate force control parameter can be set even by a person who is not skilled.

[0114] In addition, the operation information includes information related to the workpiece W1 as the object and information related to the tool for polishing. Thus, the force control parameter can be read while taking into consideration the information related to the workpiece W1 and the information related to the tool for polishing. Therefore, a more appropriate force control parameter can be set.

[0115] In addition, the information related to the workpiece W1 as the object includes at least one of information related to a shape of a polishing region of the workpiece W1, a size of the polishing region of the workpiece W1, a material of the polishing region, a surface roughness of the polishing region before polishing, and a target surface roughness of the polishing region after polishing. Thus, the force control parameter can be read while taking into consideration at least one of these pieces of information. Therefore, a more appropriate force control parameter can be set.

[0116] In addition, the tool for polishing has a grinding wheel that rotates, and the information related to the tool for polishing includes at least one of information related to a material of abrasive grains of the grinding wheel and information related to a size of the abrasive grains. Thus, the force control parameter can be read while taking into consideration at least one of these pieces of information. Therefore, a more appropriate force control parameter can be set.

[0117] Hereinafter, the force control parameter setting assistance method of the present application will be described using the flowchart shown in FIG. 10. Figures 4 to 12 The force control parameter setting assistance method of the present application will be described using the flowchart shown in FIG. 10.

[0118] Each of the steps described below is a configuration that is executed by the control device in the present embodiment, but is not limited thereto in the present application. In the case where the setting assistance section is built into the teaching device, the configuration can be executed by the teaching device.

[0119] The force control parameter setting assistance method of the present application includes a first step S101, a second step S102, and a third step S103.

[0120] First, in a first step S101, work information related to the polishing work is acquired. In this step, the worker inputs the work information from the screen shown in Fig. 1, and the acquisition unit 31D acquires the information. Figure 16

[0121] Next, in a second step S102, the information of the force control parameter corresponding to the work information acquired in the first step S101 is selected and read from the storage unit 3C in which a plurality of pieces of information of force control parameters are stored.

[0122] At this time, when the acquired work information is set as first work information and the work information stored in the storage unit 3C is set as second work information, the first work information and the second work information are compared, and the information of the force control parameter corresponding to the second work information having the highest degree of coincidence is read. In the present embodiment, the information of the force control parameter corresponding to the second work information having a high priority and a coincident category is read.

[0123] Thus, the work information is classified by category, and a priority order in which the force control parameter information is read in the second step is assigned to the category. Thereby, a more appropriate force control parameter can be set.

[0124] Note that the present application is not limited to this configuration, and for example, a configuration in which the categories of the first work information and the second work information are compared, and the information of the force control parameter corresponding to the second work information having the largest number of coincident categories is read can be employed.

[0125] Next, in a third step S103, the information of the force control parameter read in the second step S102 is displayed on the display unit 41. That is, a signal for displaying the information of the force control parameter on the display unit 41 is generated, and transmitted to the teaching device 4. Thereby, the display unit 41 can display the force control parameter appropriate for the polishing work to be performed next. Therefore, the worker can directly set the displayed force control parameter, or can set it after making a slight adjustment.

[0126] Thus, the force control parameter setting assistance method of the present application is a method of assisting in setting a force control parameter for force control when a robot 10 equipped with a polishing tool at the front end is controlled by force control to perform a polishing work on a workpiece W1 as an object. In addition, the force control parameter setting assistance method has a first step of acquiring work information related to the polishing work, a second step of selecting and reading information of a force control parameter corresponding to the work information acquired in the first step from a storage unit 3C in which a plurality of pieces of information of force control parameters are stored, and a third step of displaying the information of the force control parameter read in the second step on a display unit 41. Thereby, a troublesome setting work of the past can be omitted, and an appropriate force control parameter can be set even by a person who is not skilled. ​

[0127] Note that, in the present embodiment, the robot system 100 is configured in a manner in which the end effector 20 is constituted by a polishing tool for performing polishing, and work is performed on the workpiece W1 as an object, but is not limited thereto, and can be configured in a manner in which the end effector 20 is constituted by a gripping portion, and the workpiece W1 is gripped by the gripping portion, and work is performed by a polishing tool provided separately from the robot 1. Even in such a case, the troublesome setting work of the related art can be omitted, and appropriate force control parameters can be set even by a person who is not skilled.

[0128] Other configuration examples of the robot system

[0129] Figure 16 A block diagram for explaining the robot system in a hardware-centered manner.

[0130] The overall configuration of the robot system 100A to which the robot 1, the controller 61, and the computer 62 are connected is shown in Figure 17 The control of the robot 1 can be executed by a processor in the controller 61 reading an instruction in a memory, or can be executed by a processor existing in the computer 62 reading an instruction in a memory and via the controller 61.

[0131] Therefore, either one or both of the controller 61 and the computer 62 can be understood as a "control device".

[0132] Modified example 1

[0133] Figure 17 A block diagram for explaining modified example 1 of the robot system in a hardware-centered manner.

[0134] Figure 18 The overall configuration of the robot system 100B to which the computer 63 is directly connected with the robot 1 is shown in

[0135] Therefore, the computer 63 can be understood as a "control device".

[0136] Modified example 2

[0137] Figure 18 A block diagram for explaining modified example 2 of the robot system in a hardware-centered manner.

[0138] In ​The overall configuration of the robot system 100C in which the robot 1 in which the controller 61 is built in and the computer 66 are connected, and the computer 66 is connected with the cloud 64 via a network 65 such as a LAN is shown in FIG. 12. The control of the robot 1 can be executed by a processor existing in the computer 66 reading an instruction in a memory, or by a processor existing in the cloud 64 reading an instruction in a memory via the computer 66.

[0139] Therefore, any one or any two or three of the controller 61, the computer 66, and the cloud 64 can be understood as a "control device".

[0140] The force control parameter setting assistance method and the force control parameter setting assistance system of the present application have been described above with respect to the illustrated embodiment, but the present application is not limited thereto. In addition, each part constituting the force control parameter setting assistance system can be replaced with any component configured to be able to function in the same way. In addition, any structure can be added.

Claims

1. A force control parameter setting assistance method characterized by, In a case where a robot arm having a polishing tool attached to a front end thereof is controlled by force control to perform a polishing work on an object, a force control parameter setting assistance method assists in setting a force control parameter for the force control, the force control parameter setting assistance method including: a first step of acquiring work information related to the polishing work; a second step of selecting and reading information of the force control parameter corresponding to the work information acquired in the first step from a storage section in which information of a plurality of force control parameters is stored; a third step of displaying the information of the force control parameter read in the second step on a display section; a fourth step of receiving a setting or adjustment by a worker to set the force control parameter, in the second step, when the work information acquired in the first step is set as first work information and work information stored in the storage section is set as second work information, the first work information and the second work information are compared, and information of the force control parameter corresponding to the second work information having the highest degree of coincidence is read, the work information is classified by category; a priority order is assigned to the category in which the information of the force control parameter is read in the second step, the work information includes information related to the object and information related to the polishing tool, the information related to the object includes at least one of information related to a shape of a polishing region of the object, a size of the polishing region of the object, a material of the polishing region, a surface roughness of the polishing region before polishing, and a target surface roughness of the polishing region after polishing.

2. The force control parameter setting assistance method according to claim 1, wherein the polishing tool has a rotating grinding wheel, the information related to the polishing tool includes at least one of information related to a material of abrasive grains of the grinding wheel and information related to a size of the abrasive grains. A setting assistance section assists in setting a force control parameter for force control when a robot arm having a polishing tool attached to a front end thereof is controlled by the force control to perform a polishing work on an object, 3. A force control parameter setting assistance system characterized by, the setting assistance section includes: an acquisition section that acquires work information related to the polishing work; a reading section that selects and reads information of the force control parameter corresponding to the work information acquired by the acquisition section from a storage section in which information of a plurality of force control parameters is stored; and a display control section that displays the information of the force control parameter read by the reading section on a display section, and receives a setting or adjustment by a worker to set the force control parameter, in a case where the work information acquired by the acquisition section is set as first work information and work information stored in the storage section is set as second work information, the reading section compares the first work information and the second work information, and reads information of the force control parameter corresponding to the second work information having the highest degree of coincidence, the work information is classified by category; a priority order is assigned to the category in which the information of the force control parameter is read. ​ a priority order in which the reading section is given priority in reading the information of the force control parameter, the work information includes information related to the object and information related to the polishing tool, the information related to the object includes at least one of information related to a shape of a polishing region of the object, a size of the polishing region of the object, a material of the polishing region, a surface roughness of the polishing region before polishing, and a target surface roughness of the polishing region after polishing.

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