Force sensor and chimeric system

Abstract

The present application provides a force sensor and a chimeric system. It can determine whether the force sensor is abnormal and stably perform force control of a robot or the like. The force sensor (10) includes a force receiving body (14) that receives a force or a moment acting on a detection target portion (S), and a strain generating body (16) that is provided as an elastic support body to a sensor base (12) and supports the force receiving body (14). The force sensor (10) includes two-system detection portions (28, 30) that independently detect strains of four beam portions (26) of the strain generating body (16), two-system operation circuits (34, 36) that independently perform operations on the force or the moment acting on the detection target portion (S) on the basis of detection results output from the two-system detection portions (28, 30), and two-system output portions (38, 40) that independently output operation results output from the two-system operation circuits (34, 36) as electric signals.

Description

Technical Field

[0001] The present invention relates to a force sensor for detecting force or torque acting on a part of a detection object, and a fitting system for fitting a fitting workpiece to a workpiece being fitted. Background Technology

[0002] For example, force sensors are used when performing force control on a robot. A force sensor includes a sensor base, a force-bearing body that receives the force or torque acting on the target area, such as the base of the robot's manipulator, and an elastic support body provided on the sensor base and supporting the force-bearing body. The elastic support body has at least a partially elastic portion capable of elastic deformation. The force sensor includes a strain gauge-type detection unit that detects the strain of the elastic portion of the elastic support body, an arithmetic circuit that calculates the force or torque acting on the target area based on the detection result output from the strain gauge-type detection unit, and an output unit that outputs the calculation result from the arithmetic circuit as an electrical signal (see Patent Document 1).

[0003] In addition, force sensors that replace strain gauge-type detection units, including electrostatic capacitive detection units that electrically detect the displacement of the elastic part of the elastic support, or optical detection units that optically detect the displacement of the elastic part of the elastic support, are also widely known (see Patent Documents 2 and 3).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-56729

[0007] Patent Document 2: Japanese Patent Application Publication No. 2020-118642

[0008] Patent Document 3: Japanese Patent Application Publication No. 2019-78561 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] However, in conventional force sensors, a detection unit of a system detects the strain or displacement of the elastic part of the elastic support, and an output unit of a system outputs the force or torque acting on the detected object as an electrical signal. Therefore, it is impossible to determine whether the force sensor is malfunctioning. Thus, for example, during the force control of a robot, even if the force sensor malfunctions, the state will continue, resulting in the inability to stably control the force of the robot.

[0011] Therefore, the purpose of one technical solution of the present invention is to determine whether the force sensor is abnormal and to stably perform force control of robots, etc.

[0012] Solution for solving the problem

[0013] To address the aforementioned issues, a force sensor according to one embodiment of the present invention includes: a sensor base; a force-bearing body that bears a force or torque acting on a detection object; an elastic support body disposed on the sensor base, having at least partially an elastic portion capable of elastic deformation, the elastic support body supporting the force-bearing body; two detection units that independently detect the strain or displacement of the elastic portion of the elastic support body; two operational circuits (two operational circuits) that independently perform calculations on the force or torque acting on the detection object based on the detection results output from the detection results of the corresponding detection units of the two systems; and two output units (two output units) that independently output the calculation results output from the operational circuits of the corresponding systems as electrical signals.

[0014] In addition, to address the aforementioned issues, a fitting system according to one embodiment of the present invention includes: a robot having a multi-jointed arm and a manipulator disposed at the end of the arm and holding a fitting workpiece; a force sensor disposed between the base of the manipulator and the end of the arm, detecting forces or torques acting on the manipulator; a worktable device supporting the fitting workpiece in a manner capable of changing the posture of the fitting workpiece; a robot controller that, when fitting the fitting workpiece to the workpiece, performs force control of the robot based on a calculation result output from the output of one of the two systems of the force sensor, to adjust the posture of the fitting workpiece; and a worktable controller that, when fitting the fitting workpiece to the workpiece, performs force control of the worktable device based on a calculation result output from the output of the other of the two systems of the force sensor, to adjust the posture of the fitting workpiece.

[0015] The effects of the invention

[0016] According to a technical solution of the present invention, it is possible to determine whether there is any abnormality in the force sensor and to stably perform force control of robots, etc. Attached Figure Description

[0017] Figure 1 This is a schematic longitudinal sectional view of the force sensor according to Embodiment 1.

[0018] Figure 2 yes Figure 1 A schematic front view of the force sensor shown.

[0019] Figure 3 yes Figure 1A schematic top view of the force sensor shown.

[0020] Figure 4 yes Figure 1 A schematic side view of the force sensor shown.

[0021] Figure 5 This is a schematic top view of the strain generator of the force sensor in Embodiment 1.

[0022] Figure 6 This is a schematic longitudinal sectional view of the force sensor according to Embodiment 2.

[0023] Figure 7 This is a schematic top view of the first strain generator of the force sensor in Embodiment 2.

[0024] Figure 8 This is a schematic top view of the second strain generator of the force sensor in Embodiment 2.

[0025] Figure 9 This is a schematic diagram illustrating the fitting system of embodiment 3.

[0026] Figure 10 This is an explanation Figure 9 The flowchart shows the operation of the interlocking system.

[0027] Explanation of reference numerals in the attached figures

[0028] 10. Force sensor; 12. Sensor base; 14. Force-bearing body; 16. Strain generator (elastic support); 18. Core; 22. Ring; 26. Crossbeam (elastic part); 28. First detection unit (detection unit of one system); 30. Second detection unit (detection unit of another system); 34. First arithmetic circuit (arithmetic circuit of one system); 36. Second arithmetic circuit (arithmetic circuit of another system); 38. First interface (first output unit, output unit of one system); 40. Second interface (second output unit, 42. Force sensor; 44. First strain generator (elastic support); 46. Second strain generator (elastic support); 48. First core; 52. First ring; 56. First crossbeam (elastic part); 58. Second core; 62. Second ring; 68. Fitting system; 70. Robot; 72. Arm; 74. Manipulator; 76. Worktable device; 82. Robot controller; 84. Worktable controller; WA. Convex workpiece (fitting workpiece); WB. Concave workpiece (fitted workpiece). Detailed Implementation

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. As shown in the drawings, the direction of the central axis of the force sensor is referred to as the Z-axis direction, and the two directions orthogonal to the direction of the central axis of the force sensor are referred to as the X-axis direction and the Y-axis direction.

[0030] [Implementation Method 1]

[0031] based on Figures 1-5 The structure of the force sensor 10 in Embodiment 1 is explained.

[0032] like Figures 1-4 As shown, the force sensor 10 in Embodiment 1 is a six-axis force sensor that detects forces acting on the target part S in each axial direction (X-axis, Y-axis, and Z-axis) and torques about each axis (X-axis, Y-axis, and Z-axis). The force sensor 10 is disposed between the target part S and the opposite part T. Furthermore, the force sensor 10 is not limited to a six-axis force sensor; it can also be a force sensor that detects forces in a predetermined axial direction or torques about a predetermined axis.

[0033] The force sensor 10 includes a cylindrical sensor base 12, which is mounted at a corresponding location T. Two corner portions 12a and 12b are formed on both sides of the sensor base 12 in the X-axis direction.

[0034] A circular plate-shaped force-bearing body 14 is provided on one side of the sensor base 12 in the Z-axis direction to bear the force and torque acting on the detection target part S. The force-bearing body 14 is installed on the detection target part S. A small gap C in the Z-axis direction, for example, about 1 mm, is formed between the force-bearing body 14 and the sensor base 12, allowing the force-bearing body 14 to move relative to the sensor base 12 in accordance with the gap C.

[0035] (Strain generator acting as an elastic support)

[0036] like Figure 1 and 5As shown, a strain generator 16, serving as an elastic support for a force-bearing body 14, is provided within the sensor base 12. The strain generator 16 and the force-bearing body 14 are concentric. The strain generator 16 has a circular core 18, which is fixed relative to the force-bearing body 14 via a cylindrical connecting member 20. The strain generator 16 has a ring 22 surrounding the core 18, which is fixed relative to the sensor base 12 via an annular spacer 24. The strain generator 16 has four crossbeams 26 connected to the outer circumferential surface of the core 18 and the inner circumferential surface of the ring 22. The four crossbeams 26 are arranged at equal intervals along the circumference. When the core 18 and the ring 22 are considered as rigid bodies, the four crossbeams 26 are equivalent to elastic portions capable of elastic deformation. Furthermore, the number of crossbeams 26 is not limited to four; three or more are acceptable.

[0037] like Figure 5 As shown, each crossbeam portion 26 is provided with a first detection unit 28 for detecting its strain. Each first detection unit 28 has multiple strain gauges (not shown) respectively disposed on the surface and back surface of each crossbeam portion 26. Each crossbeam portion 26 is provided with a second detection unit 30 that independently detects its strain relative to the first detection unit 28. Each second detection unit 30 has multiple strain gauges (not shown) respectively disposed on the surface and back surface of each crossbeam portion 26. That is, the strain generator 16, which serves as an elastic support, is provided with two systems of strain gauge-type detection units that independently detect the strain of the four crossbeam portions 26, which are elastic parts. The four first detection units 28 constitute one system of strain gauge-type detection units in the two systems of strain gauge-type detection units that independently detect the strain of the four crossbeam portions 26. The four second detection units 30 constitute the other system of strain gauge-type detection units in the two systems of strain gauge-type detection units that independently detect the strain of the four crossbeam portions 26. That is, the strain gauge type detection units (first detection unit 28 and second detection unit 30) of the two systems independently detect the strain of the elastic part (beam part 26) of the elastic support (strain generator 16).

[0038] Furthermore, the force sensor 10 may also include two systems of electrostatic capacitive detection units (not shown) that independently electrically detect the displacement of the four crossbeam portions 26, or two systems of optical detection units (not shown) that independently optically detect the displacement of the four crossbeam portions 26, instead of two systems of strain gauge detection units. That is, the two systems of detection units (first detection unit 28 and second detection unit 30) independently detect the strain or displacement of the plurality of crossbeam portions (26).

[0039] like Figure 1As shown, a base plate 32 for unified control of the detection action of the force sensor 10 is disposed within the sensor base 12. A first arithmetic circuit 34 with a processor (not shown) is mounted on the base plate 32. The first arithmetic circuit 34 calculates the force and torque acting on the detection target part S based on the detection results output from the four first detection units 28 of the detection unit constituting one of the two systems. A second arithmetic circuit 36 ​​with a processor (not shown) is mounted on the base plate 32. The second arithmetic circuit 36 ​​calculates the force and torque acting on the detection target part S based on the detection results output from the four second detection units 30 of the detection unit constituting the other system. In other words, the first arithmetic circuit 34 and the second arithmetic circuit 36 ​​constituting the two systems independently calculate the force and torque acting on the detection target part S based on the detection results output from the strain gauge type detection units of the corresponding system in the two systems' strain gauge type detection units. The specific calculation methods of the first arithmetic circuit 34 and the second arithmetic circuit 36 ​​are known, therefore their description is omitted.

[0040] like Figure 1 and Figure 2 As shown, a first interface 38 serving as a first output unit is provided near one corner 12a of the sensor base 12. This first output unit outputs the calculation result from the first arithmetic circuit 34 as an electrical signal. The first interface 38 is connected to the first arithmetic circuit 34. A second interface 40 serving as a second output unit is provided near the other corner 12b of the sensor base 12. This second output unit outputs the calculation result from the second arithmetic circuit 36 ​​as an electrical signal. The second interface 40 is connected to the second arithmetic circuit 36. That is, the sensor base 12 has two system output units (first interface 38 and second interface 40) that independently output the calculation results from the corresponding system's arithmetic circuits (first arithmetic circuit 34 and second arithmetic circuit 36) as electrical signals.

[0041] Two strain gauge-type detection units (four first detection units 28 and four second detection units 30) independently detect the strain of the four crossbeam sections 26. A first calculation circuit 34 calculates the force and torque acting on the detection target section S based on the detection results output from the four first detection units 28 constituting one system. A second calculation circuit 36 ​​calculates the force and torque acting on the detection target section S based on the detection results output from the four second detection units 30 constituting the other system. A first interface 38 outputs the calculation results from the first calculation circuit 34 as an electrical signal, and a second interface 40 outputs the calculation results from the second calculation circuit 36 ​​as an electrical signal.

[0042] Therefore, it is possible to determine whether the difference between the force and torque output from the first interface 38 and the force and torque output from the second interface 40 exceeds a threshold for anomaly detection. If the difference exceeds the threshold, the force sensor 10 is determined to be malfunctioning; if the difference does not exceed the threshold, the force sensor 10 is determined to be functioning normally. Here, the threshold for anomaly detection is a threshold used to determine whether the force sensor 10 is malfunctioning. The entity that determines whether the threshold for anomaly detection has been exceeded is an external controller (not shown) electrically connected to the force sensor 10, but it can also be the force sensor 10 itself.

[0043] Therefore, according to Embodiment 1, it is possible to determine whether the force sensor 10 is abnormal, and force control of robots and the like using the force sensor 10 can be performed stably.

[0044] As described above, the detection units (first detection unit 28 and second detection unit 30) of the two systems independently detect the strain or displacement of the elastic portion (beam portion 26) of the elastic support (strain generator 16). The arithmetic circuits (first arithmetic circuit 34 and second arithmetic circuit 36) of the two systems independently calculate the force or torque acting on the detection target part (S) based on the detection results output from the corresponding system's detection unit. Then, the output units (first interface 38 and second interface 40) of the two systems independently output the calculation results from the corresponding system's arithmetic circuit as electrical signals. Therefore, it is possible to determine whether the difference between the force or torque output from one system's output unit and the force or torque output from the other system's output unit exceeds an anomaly detection threshold. Therefore, it is possible to determine whether the force sensor is malfunctioning, and to stably perform force control on robots or similar devices using the force sensor.

[0045] [Implementation Method 2]

[0046] Reference Figures 6-8 Other embodiments of the present invention will be described below. Furthermore, for ease of explanation, components having the same function as those described in Embodiment 1 will be labeled with the same reference numerals and their descriptions will not be repeated.

[0047] like Figure 6 As shown, the force sensor 42 in Embodiment 2 is a six-axis force sensor that detects forces acting on the target part S in each axial direction (X-axis, Y-axis, and Z-axis) and torques about each axis (X-axis, Y-axis, and Z-axis). The force sensor 42 is disposed between the target part S and the opposing part T. Except for certain areas, the force sensor 42 has a connection to the force sensor 10 (see reference 10). Figure 1 The same structure will be described only for the structure of force sensor 42 that differs from that of force sensor 10. Furthermore, force sensor 42 is not limited to a six-axis force sensor; it can also be a force sensor that detects force in a predetermined axial direction or torque about a predetermined axis.

[0048] like Figure 6 and Figure 7 As shown, the force sensor 42, acting as an elastic support, includes a first strain generator 44 and a second strain generator 46 overlapping in the Z-axis direction, replacing the strain generator 16 (see reference). Figure 5 Furthermore, the specific structures of the first strain generator 44 and the second strain generator 46 are as follows.

[0049] A first strain generator 44, constituting a partial elastic support, is provided within the sensor base 12. The first strain generator 44 is concentric with the force-bearing body 14. The first strain generator 44 has a circular plate-shaped first core 48, which is fixed relative to the force-bearing body 14 via a cylindrical first connecting member 50. The first strain generator 44 has a first ring portion 52 surrounding the first core 48, which is fixed relative to the sensor base 12 via an annular first spacer 54. The first strain generator 44 has four first crossbeam portions 56 connected to the outer peripheral surface of the first core 48 and the inner peripheral surface of the first ring portion 52. The four first crossbeam portions 56 are arranged at equal intervals along the circumference. When the first core 48 and the first ring portion 52 are considered as rigid bodies, the four first crossbeam portions 56 correspond to elastic portions capable of elastic deformation. Furthermore, the number of the first crossbeam 56 is not limited to four; any number of three or more is acceptable.

[0050] like Figure 6 and Figure 8As shown, a second strain generator 46 constituting a partial elastic support is provided within the sensor base 12. The second strain generator 46 is concentric with and overlaps with the first strain generator 44. The second strain generator 46 has a circular plate-shaped second core 58, which is fixed relative to the first core 48 of the first strain generator 44 via a cylindrical second connecting member 60. The second strain generator 46 has a second ring portion 62 surrounding the second core 58, which is fixed relative to the sensor base 12 via an annular second spacer 64. The second strain generator 46 has four second crossbeam portions 66 connected to the outer peripheral surface of the second core 58 and the inner peripheral surface of the second ring portion 62, and the four second crossbeam portions 66 are arranged at equal intervals along the circumference. When the second core portion 58 and the second ring portion 62 are considered as rigid bodies, the four second crossbeam portions 66 are equivalent to elastic portions capable of elastic deformation. The four second crossbeam portions 66 are configured such that when the load-bearing body 14 is subjected to force and torque, strain corresponding to the strain of the four first crossbeam portions 56 is generated in the four second crossbeam portions 66. Furthermore, the number of second crossbeam portions 66 is not limited to four; three or more are acceptable.

[0051] like Figures 6-8 As shown, in Embodiment 2, the first detection unit 28 is provided on each of the first crossbeam portions 56 of the first strain generator 44, instead of on each of the crossbeam portions 26 of the strain generator 16. Each first detection unit 28 detects the strain of each of the first crossbeam portions 56 of the first strain generator 44. Each first detection unit 28 has a plurality of strain gauges (not shown) respectively disposed on the surface and back surface of each of the first crossbeam portions 56 of the first strain generator 44. Furthermore, the second detection unit 30 is provided on each of the second crossbeam portions 66 of the second strain generator 46, instead of on each of the crossbeam portions 26 of the strain generator 16. Each second detection unit 30 detects the strain of each of the second crossbeam portions 66 of the second strain generator 46. Each second detection unit 30 has a plurality of strain gauges (not shown) respectively disposed on the surface and back surface of each of the second crossbeam portions 66 of the second strain generator 46. That is, the elastic support (first strain generator 44 and second strain generator 46) is provided with two systems of strain gauge-type detection units that independently detect the strain of the elastic parts (four first crossbeam parts 56 and four second crossbeam parts 66). One system of strain gauge-type detection unit detects the strain of the four first crossbeam parts 56, and the other system of strain gauge-type detection unit detects the strain of the four second crossbeam parts 66.

[0052] Furthermore, the force sensor 42 may also include a capacitive sensing unit (not shown) that electrically detects the displacement of the four first crossbeam portions 56, or an optical sensing unit (not shown) that optically detects the displacement of the four first crossbeam portions 56, instead of a strain gauge sensing unit. The force sensor 42 may also include a capacitive sensing unit (not shown) that electrically detects the displacement of the four second crossbeam portions 66, or an optical sensing unit (not shown) that optically detects the displacement of the four second crossbeam portions 66, instead of a strain gauge sensing unit.

[0053] One system's strain gauge-type detection unit (four first detection units 28) detects the strain of four first crossbeam sections 56. Another system's strain gauge-type detection unit (four second detection units 30) detects the strain of four second crossbeam sections 66. A first calculation circuit 34 calculates the force and torque acting on the detection target part S based on the detection results output from the four first detection units 28 constituting one system. A second calculation circuit 36 ​​calculates the force and torque acting on the detection target part S based on the detection results output from the four second detection units 30 constituting the other system. Then, a first interface 38 outputs the calculation results from the first calculation circuit 34 as an electrical signal, and a second interface 40 outputs the calculation results from the second calculation circuit 36 ​​as an electrical signal.

[0054] Therefore, it is possible to determine whether the difference between the force and torque output from the first interface 38 and the force and torque output from the second interface 40 exceeds the threshold for anomaly detection. If the difference exceeds the threshold for anomaly detection, it is determined that the force sensor 42 is abnormal; if the difference does not exceed the threshold for anomaly detection, it is determined that the force sensor 42 is not abnormal.

[0055] Therefore, according to Embodiment 2, it is possible to determine whether the force sensor 42 is malfunctioning, and force control of the robot or the like using the force sensor 42 can be performed stably. In particular, even if permanent strain occurs in a local part of the elastic support, i.e., in either the first strain generator 44 or the second strain generator 46, it is possible to determine that the force sensor 42 is malfunctioning, and force control of the robot or the like using the force sensor 42 can be performed more stably.

[0056] As described above, the detection unit (first detection unit 28) of one system detects the strain or displacement of the plurality of first crossbeams (56). The detection unit (second detection unit 30) of the other system detects the strain or displacement of the plurality of second crossbeams (66). Thus, even if permanent strain occurs locally in one of the first strain generators (44) and the second strain generators (46), i.e., the elastic support (first strain generator 44 and second strain generator 46), it can be determined that the force sensor (42) is abnormal.

[0057] [Implementation Method 3]

[0058] The following is for reference Figure 9 and Figure 10 Other embodiments of the present invention will be described below. Furthermore, for ease of explanation, components having the same function as those described in Embodiments 1 and 2 will be labeled with the same reference numerals and their descriptions will not be repeated.

[0059] like Figure 9 As shown, the fitting system 68 of Embodiment 3 is a system for fitting a convex workpiece WA, which is a fitting workpiece, and a concave workpiece WB, which is a fitted workpiece. Moreover, the specific structure of the fitting system 68 is as follows.

[0060] The fitting system 68 includes a robot 70 that dominates the fitting action of the protruding workpiece WA. The robot 70 includes a multi-jointed arm 72 and a manipulator 74 located at the end of the arm 72 and holding the protruding workpiece WA.

[0061] The fitting system 68 includes a force sensor 10 (or 42) for detecting the force and torque acting on the manipulator 74. The force sensor 10 (or 42) is configured as described above and is disposed at the detection target location S (see reference 1). Figure 1 The base of the robotic arm 74 and the opposite part T (refer to) Figure 1 Between the ends of the arms 72.

[0062] The fitting system 68 includes a Stewart-Platform type worktable device 76 disposed near the robot 70 and assisting in the fitting action of the convex workpiece WA. The worktable device 76 includes a support platform 78 supporting the concave workpiece WB and a parallel linkage mechanism 80 that allows the support platform 78 to move in a manner that can change the posture of the concave workpiece WB. In other words, the worktable device 76 supports the concave workpiece WB in a manner that allows for changing the posture of the concave workpiece WB. Furthermore, the worktable device 76 can be considered as a second robot.

[0063] The interlocking system 68 includes a robot controller 82 that controls the robot 70. The robot controller 82 is electrically connected to a first interface 38 of the force sensor 10 (or 42). The robot controller 82 has a memory (not shown) that stores robot control programs for controlling the robot 70 and a microprocessor (not shown) that interprets and executes the robot control programs.

[0064] The robot controller 82 performs position control of the robot 70 based on the robot control program to engage the convex workpiece WA with the concave workpiece WB. Furthermore, while engaging the convex workpiece WA with the concave workpiece WB, the robot controller 82 performs force control of the robot 70 based on the calculation results output from the first interface 38 to adjust the posture and position of the convex workpiece WA. In other words, the robot controller 82 performs force control of the robot 70 while engaging the convex workpiece WA with the concave workpiece WB to reduce the force and torque output from the first interface 38.

[0065] The fitting system 68 includes a table controller 84 that controls the table device 76. The table controller 84 is electrically connected to a second interface 40 of the force sensor 10 (or 42). The table controller 84 has a memory (not shown) that stores table control programs for controlling the table device 76 and a microprocessor (not shown) that interprets and executes the table control programs.

[0066] When engaging the convex workpiece WA and the concave workpiece WB, the table controller 84 performs force control on the table device 76 based on the calculation results output from the second interface 40 to adjust the posture and position of the concave workpiece WB. In other words, when engaging the convex workpiece WA and the concave workpiece WB, the table controller 84 performs force control on the table device 76 to reduce the force and torque output from the second interface 40.

[0067] The integrated system 68 includes a main controller (not shown) that uniformly controls the entire system. The main controller is electrically connected to a first interface 38, a second interface 40, a robot controller 82, and a workbench controller 84. The main controller determines whether the difference between the force and torque output from the first interface 38 and the force and torque output from the second interface 40 exceeds a threshold for anomaly detection. If the difference exceeds the threshold, the main controller determines that the force sensor 10 (or 42) is malfunctioning. If the difference does not exceed the threshold, the main controller determines that the force sensor 10 (or 42) is functioning normally.

[0068] like Figure 9 and Figure 10As shown, the robot controller 82 performs position control of the robot 70 so that the manipulator 74 moves from its original position to the vicinity of the mounting area of ​​the convex workpiece WA. Next, the robot controller 82 controls the robot 70 so that the manipulator 74 grasps the convex workpiece WA. Figure 10 (Step S101 in the text). Then, the robot controller 82 controls the robot 70 so that the manipulator 74 and the convex workpiece WA are positioned above the concave workpiece WB on the support platform 78. Figure 10 Step S102 in the process). Thus, the engagement action of the convex workpiece WA begins ( Figure 10 In step S103, the force control of the robot 70 and the workbench device 76 is activated. Figure 10 Step S104 in the process.

[0069] When engaging the convex workpiece WA and the concave workpiece WB, the robot controller 82 performs force control on the robot 70 based on the calculation results output from the first interface 38 to adjust the posture and position of the convex workpiece WA. Additionally, the table controller 84 performs force control on the table device 76 based on the calculation results output from the second interface 40 to adjust the posture and position of the concave workpiece WB. This allows for the simultaneous insertion of the convex workpiece WA into the concave workpiece WB while adjusting the posture and position of both convex and concave workpieces. Figure 10 Step S105 in the process.

[0070] Then, if the force in the Z-axis direction, which is one of the calculation results output from the first interface 38, exceeds the threshold for completion judgment, the robot controller 82 determines that the insertion of the convex workpiece WA has been completed. Figure 10 Step S106). The threshold for completion judgment refers to the threshold used to determine whether the insertion action of the protruding workpiece WA has been completed. Next, the robot controller 82 controls the robot 70 to make the manipulator 74 leave the protruding workpiece WA. Figure 10 Step S107 in the process. As a result, the force control of the robot 70 and the worktable device 76 is shut off. Figure 10 Step S108 in the process.

[0071] Furthermore, the robot controller 82 controls the robot 70 so that the manipulator 74 is positioned above the convex workpiece WA and the worktable assembly 76. Figure 10 In step S109), the engagement action of the convex workpiece WA is thus completed. Figure 10 (Step S110). The robot controller 82 performs position control on the robot 70 so that the manipulator 74 returns to its original position.

[0072] That is, according to the structure of Embodiment 3, as described above, when the convex workpiece WA and the concave workpiece WB are engaged, the robot controller 82 performs force control of the robot 70, and the worktable controller 84 performs force control of the worktable device 76. Therefore, according to Embodiment 3, compared with the case where only the robot 70 is force controlled, the production cycle time can be reduced, and the convex workpiece WA and the concave workpiece WB can be engaged in a short time.

[0073] As described above, when the mating workpiece (convex workpiece WA) and the mated workpiece (concave workpiece WB) are mated, the robot controller (82) performs force control on the robot (70) based on the calculation results output from the output unit (first interface 38) of the system to adjust the posture of the mating workpiece. Additionally, the table controller (84) performs force control on the table device (76) based on the calculation results output from the output unit (second interface 40) of another system to adjust the posture of the mated workpiece. Therefore, compared to the case where only the robot's force control is performed, the production cycle time can be reduced, allowing the mating workpiece and the mated workpiece to be mated in a shorter time.

[0074] [Additional Notes]

[0075] This invention is not limited to the aforementioned embodiments, but can be modified in various ways within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of this invention.

Claims

1. A force sensor, comprising a force-receiving body that bears a force or torque acting on a part of a detected object. The force sensor is characterized by including: Sensor base; An elastic support body is disposed on the sensor base and has at least a partially elastic portion capable of elastic deformation, the elastic support body supporting the force-bearing body; The detection units of the two systems independently detect the strain or displacement of the elastic part of the elastic support; The two systems' operational circuits independently calculate the force or torque acting on the detected object based on the detection result output from the detection unit of one of the two systems' detection units. as well as The output sections of the two systems independently output the computation results from the computational circuit of one of the corresponding systems as electrical signals. The computing circuits of the two systems are located inside the sensor base. One of the two systems' operational circuits calculates the force or torque acting on the detected object based on the detection result from the detection unit of one of the two systems' detection units. The other of the two systems' operational circuits calculates the force or torque acting on the object being detected based on the detection result from the detection unit of the other of the two systems' detection units.

2. The force sensor according to claim 1, characterized in that, The elastic support is a strain generator. The strain generator has the following characteristics: The core is fixed relative to the force-bearing body; A ring portion, which is fixed relative to the sensor base, surrounds the core portion; and Multiple crossbeam portions, which serve as the elastic portions, are arranged at equal intervals along the circumferential direction, in a manner that connects to the outer peripheral surface of the core portion and the inner peripheral surface of the ring portion.

3. The force sensor according to claim 1, characterized in that, The elastic support body is composed of overlapping first strain generators and second strain generators. The first strain generator has: The first core is fixed relative to the force-bearing body; A first ring portion, which is fixed relative to the sensor base, surrounds the first core portion; and Multiple first crossbeam portions, which serve as the elastic portions, are arranged in a manner that connects to the outer peripheral surface of the first core portion and the inner peripheral surface of the first ring portion, and are equally spaced along the circumferential direction. The second strain generator has: The second core is fixed relative to the first core of the first strain generator; The second ring portion, which is fixed relative to the sensor base, surrounds the second core portion; and Multiple second crossbeam portions, which serve as the elastic portions, are arranged in a manner that connects to the outer peripheral surface of the second core portion and the inner peripheral surface of the second ring portion, and are equally spaced along the circumferential direction. The detection unit of one of the two systems detects the strain or displacement of the plurality of first crossbeams, and the detection unit of the other system detects the strain or displacement of the plurality of second crossbeams.

4. The force sensor according to any one of claims 1 to 3, characterized in that, The detection units of the two systems are strain gauge type detection units.

5. A fitting system comprising a robot having a multi-jointed arm and a manipulator disposed at the head end of said arm and for holding a fitting workpiece. The characteristic of this interlocking system is that it includes: The force sensor according to any one of claims 1 to 4 is disposed between the base of the manipulator and the end of the arm to detect the force or torque acting on the manipulator. A worktable device that supports the workpiece in a manner that allows for changes in the orientation of the workpiece. The robot controller performs force control on the robot to adjust the posture of the mating workpiece when the mating workpiece is mated with the workpiece being mated, based on the calculation results output from the output of one of the two systems of the force sensor. as well as The worktable controller, when engaging the workpiece and the workpiece to be engaged, performs force control of the worktable device based on the calculation results output from the output of the other system of the two systems of the force sensor, so as to adjust the posture of the workpiece to be engaged.

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