Force information display device

Abstract

To provide a force information display device that allows a worker to easily grasp the force and moment of an absolute coordinate system acting on a workpiece.SOLUTION: A control unit (11) executes: first calculation processing that calculates the displacement angle of a robot hand (40) from the angular velocity input from a gyro sensor (53); first display processing that converts at least one of the force and moment of a force sensor coordinate system fixed to a force sensor input from the force sensor (51) into force or moment of an absolute coordinate system fixed to the ground on the basis of the displacement angle of the robot hand (40), and displays it on a display (14); and second display processing that displays the relationship between the absolute coordinate system and the force sensor coordinate system on the display (14) on the basis of the displacement angle of the robot hand (40).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a force information display device that displays force information detected by a force sensor. [Background technology]

[0002] Patent Document 1 describes a polishing robot that is capable of direct teaching. In the polishing robot, a workpiece to be polished is attached to the tip of the robot arm via a joint. It also describes that a force sensor is attached between the robot arm and the joint. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-44449 A Summary of the Invention [Problem to be solved by the invention]

[0004] When monitoring at least one of the force and moment acting on a force sensor attached to such a robot arm, the coordinate axes of the force sensor coordinate system fixed to the force sensor are inclined with respect to the coordinate axes of the absolute coordinate system fixed to the ground. As a result, the force and moment of the force sensor coordinate system acting on the force sensor differ from the force and moment of the absolute coordinate system, which poses a problem that it is difficult for an operator to grasp the force and moment of the absolute coordinate system acting on a workpiece.

[0005] One aspect of the present invention has been made in consideration of the above-mentioned problems, and has an object to provide a force information display device that enables a worker to easily grasp forces and moments in an absolute coordinate system acting on a workpiece. [Means for solving the problem]

[0006] In order to solve the above problems, a force information display device according to one embodiment of the present invention includes a signal input unit to which detection signals are input from a force sensor and a gyro sensor arranged between a robot arm and a robot hand, and a control unit, wherein the control unit executes a first calculation process to calculate a displaced angle of the robot hand from the angular velocity input from the gyro sensor via the signal input unit, and a first display process to convert at least one of the force and moment in a force sensor coordinate system fixed to the force sensor input from the force sensor via the signal input unit based on the displaced angle of the robot hand calculated in the first calculation process into a force or moment in an absolute coordinate system fixed to the ground and display the force or moment on a display, or a second display process to display a relationship between the absolute coordinate system and the force sensor coordinate system on the display based on the displaced angle of the robot hand calculated in the first calculation process. Effect of the Invention

[0007] According to one aspect of the present invention, at least one of the forces and moments in the absolute coordinate system, or the relationship between the absolute coordinate system and the force sensor coordinate system, is displayed on a display, allowing an operator to easily grasp the forces and moments in the absolute coordinate system acting on the workpiece. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a force information display system according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of an electrical configuration of the force information display device according to the first embodiment. [Diagram 3] 13 is a flowchart showing an example of a first force information display process executed by the controller according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a display screen displayed on a display of the force information display device in accordance with the first embodiment. [Diagram 5] 13 is a flowchart showing an example of a second force information display process executed by a controller according to the second embodiment. [Figure 6] FIG. 13 is a diagram showing an example of a display screen displayed on a display of the force information display device in accordance with the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a detailed description will be given of a first embodiment and a second embodiment of the present invention with reference to the drawings. The same or equivalent components and members shown in each drawing are denoted by the same reference numerals, and redundant descriptions will be omitted as appropriate.

[0010] [Embodiment 1] [Schematic configuration of force information display system 100] First, a schematic configuration of a force information display system 100 according to embodiment 1 of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of a schematic configuration of force information display system 100 according to embodiment 1. As shown in Fig. 1, force information display system 100 includes a force information display device 10, a robot arm 30, a robot hand 40, a force sensor 51, a three-axis acceleration sensor 52, and a three-axis gyro sensor 53. Note that robot arm 30 is configured to enable teaching by direct teaching, online teaching, or the like.

[0011] [Schematic configuration of robot arm 30] The robot arm 30 is a multi-joint arm including a plurality of arms 31. The robot arm 30 has four arms 31 connected by three joints 32. However, the number of arms 31 included in the robot arm 30 is not limited to four, and the number of joints 32 connecting the arms 31 is not limited to three.

[0012] The robot hand 40 is configured to be able to grip a workpiece W with two claws 41 that are opened and closed by an actuator (not shown). The robot hand 40 is attached to the robot arm 30 via a force sensor 51, a three-axis acceleration sensor 52, and a three-axis gyro sensor 53. The robot arm 30 has six degrees of freedom and supports the position and posture of the robot hand 40 so that it can be changed.

[0013] The force sensor 51 detects the direction and magnitude of the force and moment acting on itself. The force sensor 51 is a six-axis force sensor that detects force components FX, FY, and FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of a force sensor coordinate system with the axial direction being the Z-axis direction, and moment components MX, MY, and MZ with the X-axis, Y-axis, and Z-axis as the rotation axes. The force sensor 51 is disposed coaxially with the robot hand 40. An example of the three axes of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system fixed to the force sensor 51 is shown by solid lines in FIG. 1. Also, an example of the three axes of the X-axis, Y-axis, and Z-axis of an absolute coordinate system fixed to the ground with the vertical direction being the Z-axis direction is shown by dashed lines in FIG. 1.

[0014] Therefore, the force sensor 51 detects force components FX, FY, FZ in the three axial directions of the X-axis, Y-axis, and Z-axis acting on the robot hand 40, and moment components MX, MY, MZ about the three axes of rotation, the X-axis, Y-axis, and Z-axis. Hereinafter, FX, FY, FZ, MX, MY, MZ will also be referred to as force components or simply as detected values. The force sensor 51 outputs a signal related to the detected values ​​to the force information display device 10.

[0015] The three-axis acceleration sensor 52 detects the acceleration acting on itself. The three-axis acceleration sensor 52 is arranged so that its Z-axis direction is coaxial with the Z-axis of the force sensor 51, and detects acceleration components AX, AY, and AZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system. Hereinafter, AX, AY, and AZ will also be referred to as acceleration components or simply as detection values. The three-axis acceleration sensor 52 outputs a signal related to the detection values ​​to the force information display device 10.

[0016] The three-axis gyro sensor 53 detects the angular velocity acting on itself. The three-axis gyro sensor 53 is arranged coaxially with the Z axis of the force sensor 51, and detects angular velocity components WX, WY, and WZ about the three axes of the X, Y, and Z axes of the force sensor coordinate system as rotation axes. Hereinafter, WX, WY, and WZ are also referred to as angular velocity components or simply as detection values. The three-axis gyro sensor 53 outputs a signal related to the detection values ​​to the force information display device 10.

[0017] [Schematic configuration of force information display device 10] The schematic configuration of force information display device 10 will be described with reference to Figs. 1 and 2. Fig. 2 is a block diagram showing an example of the electrical configuration of force information display device 10 according to embodiment 1. As shown in Fig. 2, force information display device 10 has a control unit 11, an operation unit 12, a communication unit 13, a display 14, a memory unit 15, and a signal input unit 16.

[0018] The control unit 11 is configured, for example, by a central processing unit (CPU). The control unit 11 may be configured by a graphic processing unit (GPU), a digital signal processor (DSP), a micro processing unit (MPU), a floating point number processing unit (FPU), a physics processing unit (PPU), a microcontroller, or a combination of these.

[0019] The storage unit 15 is configured with a semiconductor RAM (Random Access Memory), a flash memory, a HDD (Hard Disk Drive), an SSD (Solid State Drive), an ODD (Optical Disk Drive), or a combination of these. The control unit 11 executes various arithmetic processing based on various programs and various parameters stored in the storage unit 15.

[0020] The operation unit 12 is composed of a plurality of button switches, and pressing the button switches allows the power to be turned on and off, various instructions to be input, etc. The communication unit 13 functions as an example of a communication interface for communicating with a PC (Personal Computer) or the like. The display 14 is composed of a liquid crystal display, an organic EL display, or the like. For example, as shown in Fig. 4, the display 14 displays the force components of the force sensor coordinate system acting on the workpiece W, the three coordinate axes, and the like.

[0021] The force sensor 51, the triaxial acceleration sensor 52, and the triaxial gyro sensor 53 are electrically connected to the signal input unit 16. The signal input unit 16 outputs detection values ​​detected from the respective detection signals input from the force sensor 51, the triaxial acceleration sensor 52, and the triaxial gyro sensor 53 to the control unit 11. The control unit 11 stores the respective detection values ​​of the force sensor 51, the triaxial acceleration sensor 52, and the triaxial gyro sensor 53 input from the signal input unit 16 in the storage unit 15.

[0022] [First force information display process] Next, an example of a first force information display process executed by control unit 11 of force information display device 10 when teaching of robot arm 30 is performed with workpiece W held by robot hand 40 will be described with reference to FIGS. 3 and 4. FIG. 3 is a flowchart showing an example of a first force information display process executed by control unit 11 of force information display device 10. FIG. 4 is a diagram showing an example of a display screen displayed on display 14 of force information display device 10. The program for the first force information display process shown in FIG. 3 is pre-stored in storage unit 15.

[0023] As shown in FIG. 3, in step S11, the control unit 11 acquires the detection values ​​of the force sensor 51, the three-axis acceleration sensor 52, and the three-axis gyro sensor 53 input from the signal input unit 16, and then proceeds to processing in step S12.

[0024] Specifically, the control unit 11 stores in the memory unit 15 force components FX, FY, FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system input from the force sensor 51, and moment components MX, MY, MZ about the three axes as rotation axes. The control unit 11 stores in the memory unit 15 acceleration components AX, AY, AZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system input from the three-axis acceleration sensor 52. The control unit 11 stores in the memory unit 15 angular velocity components WX, WY, WZ about the three axes of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system input from the three-axis gyro sensor 53.

[0025] In step S12, the control unit 11 reads out the angular velocity components WX, WY, and WZ about the three axes of the force sensor coordinate system of the three-axis gyro sensor 53 as rotation axes from the storage unit 15. Then, the control unit 11 calculates the displacement angle of the robot hand 40 from the read angular velocity components WX, WY, and WZ, that is, the orientation of the workpiece W after it has been displaced, and stores the calculated angle in the storage unit 15.

[0026] Furthermore, the control unit 11 reads out the acceleration components AX, AY, and AZ in the three-axis directions of the force sensor coordinate system of the three-axis acceleration sensor 52 from the storage unit 15. Then, the control unit 11 calculates the distance traveled by the robot hand 40 in the three-axis directions from the read-out acceleration components AX, AY, and AZ, i.e., the distance traveled by the workpiece W in the three-axis directions, and stores this in the storage unit 15, after which the process proceeds to step S13.

[0027] In step S13, the control unit 11 reads out the mass MH of the robot hand 40 from the storage unit 15. Then, the control unit 11 sequentially reads out the acceleration components AX, AY, and AZ in the three-axis directions of the force sensor coordinate system of the three-axis acceleration sensor 52 from the storage unit 15, and multiplies them by the mass MH of the robot hand 40 to calculate the inertial force components FAX, FAY, and FAZ in the three-axis directions of the robot hand 40. After storing the inertial force components FAX, FAY, and FAZ in the three-axis directions of the robot hand 40 in the storage unit 15, the control unit 11 proceeds to the processing of step S14. The mass MH of the robot hand 40 is stored in the storage unit 15 in advance.

[0028] In step S14, the control unit 11 reads out from the storage unit 15 the force components FX, FY, FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system input from the force sensor 51, and the inertial force components FAX, FAY, FAZ in the three axial directions of the robot hand 40. Then, the control unit 11 subtracts the inertial force components FAX, FAY, FAZ in the three axial directions from the force components FX, FY, FZ in the three axial directions, respectively, and stores the results in the storage unit 15 as force components FX, FY, FZ (corrected forces) in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W. After that, the control unit 11 proceeds to the processing of step S15.

[0029] In step S15, the control unit 11 reads out force components FX, FY, FZ (correction forces) in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W from the storage unit 15. The control unit 11 also reads out moment components MX, MY, MZ about the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system stored in the storage unit 15 in step S11. Then, the control unit 11 displays the force components FX, FY, FZ (correction forces) in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W and the moment components MX, MY, MZ about the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system on the display 14. Thereafter, the control unit 11 proceeds to the process of step S16.

[0030] In addition, the control unit 11 may display on the display 14 at least one of the force components FX, FY, FZ (correction forces) in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W, and the moment components MX, MY, MZ about the three axes of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system as rotation axes.

[0031] In step S16, the control unit 11 displays on the display 14 the coordinate axes of the X-axis, Y-axis, and Z-axis of an absolute coordinate system with the vertical direction as the Z-axis direction. The control unit 11 also reads out the orientation of the workpiece W after displacement and the distance moved in the three axial directions of the workpiece W stored in step S12. The control unit 11 then displays on the display 14 the coordinate axes of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system, aligning the Z-axis direction of the force sensor coordinate system with the orientation of the workpiece W after displacement. The control unit 11 also displays on the display 14 the origins of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system superimposed on the origins of the X-axis, Y-axis, and Z-axis of the absolute coordinate system. After that, the control unit 11 proceeds to the process of step S17.

[0032] In step S17, the control unit 11 calculates the inclination angle θ of the Z axis of the force sensor coordinate system with respect to the Z axis of the absolute coordinate system, displays it on the display 14, and then proceeds to the processing of step S18.

[0033] Here, an example of displaying the force components of the force sensor coordinate system of the workpiece W, the coordinate axes of the absolute coordinate system, and the coordinate axes of the force sensor coordinate system on the display 14 will be described with reference to Fig. 4. As shown in Fig. 4, graphs showing changes in force components FX, FY, FZ (corrective forces) in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W are displayed in a vertical line on the left side of the screen. In addition, graphs showing changes in moment components MX, MY, MZ about the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W as rotation axes are displayed to the right of the graphs showing the force components in the three axial directions, that is, in a vertical line approximately in the center of the left-right direction of the screen.

[0034] The coordinate axes of the absolute coordinate system, with the vertical direction as the Z-axis direction, are displayed in dashed lines on the right side of the screen. Furthermore, the X-axis, Y-axis, and Z-axis of the force sensor coordinate system are displayed in solid lines superimposed on the coordinate axes of the absolute coordinate system, with the Z-axis direction of the force sensor coordinate system aligned with the orientation of the workpiece W after displacement. The origin of the coordinate axes of the force sensor coordinate system is displayed superimposed on the origin of the coordinate axes of the absolute coordinate system. Also, the inclination angle θ of the Z-axis of the force sensor coordinate system with respect to the Z-axis of the absolute coordinate system is displayed.

[0035] This allows the worker to easily check the changes in the force components FX, FY, FZ in the three-axis directions of the force sensor coordinate system of the workpiece W and the moment components MX, MY, MZ about the three axes as rotation axes. The worker can also easily check the inclination angle of the Z-axis direction of the workpiece W with respect to the vertical direction. Note that the force components FX, FY, FZ in the three-axis directions of the force sensor coordinate system of the workpiece W and the moment components MX, MY, MZ about the three axes as rotation axes may each be displayed as numerical values ​​instead of graphs.

[0036] 3, in step S18, the control unit 11 reads out from the memory unit 15 the force components FX, FY, FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system that were input from the force sensor 51 and stored in step S11 above. Then, the control unit 11 calculates a resultant force F1 acting on the robot hand 40 and the workpiece W from the force components FX, FY, FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system, and stores the resultant force F1 in the memory unit 15.

[0037] Next, the control unit 11 reads out from the memory unit 15 the acceleration components AX, AY, and AZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system that were input from the three-axis acceleration sensor 52 and stored in step S11 above. Then, the control unit 11 calculates the acceleration A1 in the movement direction of the robot hand 40 and the workpiece W, i.e., the direction in which a force acts on the robot hand 40 and the workpiece W, from the acceleration components AX, AY, and AZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system, and stores the calculated acceleration A1 in the memory unit 15.

[0038] Then, the control unit 11 reads out the mass MH of the robot hand 40 from the storage unit 15, and multiplies the mass MH of the robot hand 40 by the acceleration A1 in the movement direction to calculate the inertial force FH of the robot hand 40. The control unit 11 also multiplies the mass MH of the robot hand 40 by the gravitational acceleration G to calculate the weight MHG, which is the force of the robot hand 40 in the gravitational direction.

[0039] Then, the control unit 11 subtracts the resultant force of the inertial force FH of the robot hand 40 and the weight MHG from the resultant force F1, divides the resultant force by the value obtained by adding the acceleration A1 in the movement direction to the acceleration of gravity G, calculates the mass MW of the workpiece W, and stores it in the memory unit 15. Next, the control unit 11 multiplies the mass MW of the workpiece W by the acceleration of gravity G to calculate the weight MWG of the workpiece W, stores it in the memory unit 15, and then proceeds to the processing of step S19. This enables the control BU11 to measure the weight of the workpiece W during its transport.

[0040] In step S19, the control unit 11 reads out the weight MWG of the workpiece W from the storage unit 15, displays it on the display 14, and then proceeds to the processing of step S20. For example, as shown in Fig. 4, the control unit 11 displays the weight MWG of the workpiece W below the Z axis of the absolute coordinate system.

[0041] In step S20, the control unit 11 determines whether or not teaching of the robot arm 30 has been completed. For example, the control unit 11 determines whether or not an end button on the operation unit 12 has been pressed. If the control unit 11 determines that teaching of the robot arm 30 has not been completed (S20: NO), the control unit 11 executes the processes from step S11 onwards again. On the other hand, if the control unit 11 determines that teaching of the robot arm 30 has been completed (S20: YES), the control unit 11 ends the first force information display process.

[0042] As described above in detail, in the force information display device 10 according to the first embodiment, the three coordinate axes of the absolute coordinate system and the three coordinate axes of the force sensor coordinate system are displayed on the display 14. This allows the worker to easily grasp the angle at which the tip of the robot arm is tilted relative to the vertical direction while working, from the orientation of the Z axis of the force sensor coordinate system relative to the Z axis of the absolute coordinate system displayed on the display, and the tilt angle θ. In addition, from the force components (correction forces) in the three axial directions of the workpiece W in the force sensor coordinate system displayed on the display 14 and the moment components about the three axes, the worker can easily grasp the force with which the tip of the robot arm 30 is pressed while working.

[0043] Furthermore, the control unit 11 can measure the weight of the work W when the work W is being transported. As a result, the control unit 11 can display the weight MWG of the work W on the display 14 while the work W is being transported. Therefore, even while the work W is being transported, the worker can grasp the weight MWG of the work W in real time.

[0044] [Embodiment 2] Next, a second embodiment of the present disclosure will be described with reference to Figs. 5 and 6. Fig. 5 is a flowchart showing an example of a second force information display process executed by controller 11 according to the second embodiment. Fig. 6 is a diagram showing an example of a display screen displayed on display 14 of force information display device 10 according to the second embodiment. For ease of explanation, the same reference numerals are used to refer to members having the same functions as the members described in the first embodiment, and their explanations will not be repeated.

[0045] [Second force information display processing] Control unit 11 of force information display device 10 according to embodiment 2 executes second force information display process shown in Fig. 5 instead of the first force information display process shown in Fig. 3. The program for the second force information display process shown in Fig. 5 is stored in advance in storage unit 15.

[0046] 5, after executing the processes of steps S11 to S14, the control unit 11 proceeds to the process of step S31. In step S31, the control unit 11 reads out force components FX, FY, and FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W from the storage unit 15. The control unit 11 also reads out moment components MX, MY, and MZ about the three axes of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system as rotation axes stored in the storage unit 15 in the above step S11.

[0047] The control unit 11 also reads out from the memory unit 15 the orientation of the workpiece W after displacement and the distances moved in the three axial directions of the workpiece W calculated in step S12 above, and stores them in the memory unit 15 as displacement information of the workpiece W. Then, the control unit 11 converts the force components in the three axial directions of the force sensor coordinate system of the workpiece W and the moment components around the three axes as rotation axes into force components in the three axial directions of the absolute coordinate system of the workpiece W and moment components around the three axes of the absolute coordinate system as rotation axes, based on the displacement information of the workpiece W. Then, the control unit 11 stores the converted force components in the three axial directions of the absolute coordinate system of the workpiece W and moment components around the three axes of the absolute coordinate system as rotation axes in the memory unit 15. After that, the control unit 11 proceeds to the process of step S32.

[0048] In step S32, the control unit 11 reads out from the memory unit 15 the force components in the three axial directions of the absolute coordinate system of the workpiece W and the moment components around the three axes of the absolute coordinate system as rotation axes, displays them on the display 14, and then proceeds to processing of step S33.

[0049] In step S33, the control unit 11 executes the processes of steps S18 and S19 described above to calculate the weight MWG of the workpiece W, stores it in the memory unit 15, and then displays the weight MWG of the workpiece W on the display 14. Thereafter, the control unit 11 proceeds to the process of step S34.

[0050] Here, an example of displaying the force components of the absolute coordinate system of the workpiece W and the weight MWG of the workpiece W on the display 14 will be described with reference to Fig. 6. As shown in Fig. 6, graphs showing the changes in the force components FX, FY, FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the absolute coordinate system of the workpiece W are displayed in a vertical row on the left side of the screen.

[0051] Also, graphs showing the changes in moment components MX, MY, MZ about the three rotation axes of the X-axis, Y-axis, and Z-axis of the absolute coordinate system of the workpiece W are displayed to the right of the graphs showing the force components in the three axial directions, that is, in a vertical line approximately in the center of the left-right direction of the screen. And the weight MWG of the workpiece W is displayed on the right side of the screen.

[0052] This allows the worker to easily confirm the changes in the force components FX, FY, FZ in the three-axis directions of the absolute coordinate system of the workpiece W, and the moment components MX, MY, MZ about the three axes as rotation axes. In addition, the worker can easily confirm the weight MWG of the workpiece W.

[0053] The control unit 11 may display the force components FX, FY, FZ in the three axial directions of the absolute coordinate system of the workpiece W and the moment components MX, MY, MZ about the three axes as rotation axes as numerical values ​​instead of graphs. The control unit 11 may also display on the display 14 simultaneously the force components FX, FY, FZ in the three axial directions of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system of the workpiece W and the moment components MX, MY, MZ about the three axes of the X-axis, Y-axis, and Z-axis of the force sensor coordinate system as rotation axes.

[0054] Next, as shown in Fig. 5, in step S34, the control unit 11 determines whether or not teaching of the robot arm 30 has ended. For example, the control unit 11 determines whether or not the end button of the operation unit 12 has been pressed. If the control unit 11 determines that teaching of the robot arm 30 has not ended (S34: NO), it executes the processes from step S11 onwards again. On the other hand, if the control unit 11 determines that teaching of the robot arm 30 has ended (S34: YES), it ends the second force information display process.

[0055] As described above in detail, in force information display device 10 according to embodiment 2, force components in three axial directions and moment components about the three axes in the absolute coordinate system are displayed on display 14. This enables the worker to easily grasp the force components in the three axial directions and moment components about the three axes of the absolute coordinate system acting on workpiece W.

[0056] Furthermore, the weight of the workpiece W can be measured when the workpiece W is being transported. As a result, the control unit 11 can display the weight MWG of the workpiece W on the display 14 while the workpiece W is being transported. Therefore, even while the workpiece W is being transported, the worker can grasp the weight MWG of the workpiece W in real time.

[0057] [Variation 1] In the above-described first and second embodiments, the three-axis acceleration sensor 52 and the three-axis gyro sensor 53 may be configured as an integrated sensor. Furthermore, the force sensor 51, the three-axis acceleration sensor 52, and the three-axis gyro sensor 53 may be configured as an integrated sensor. Moreover, the force sensor 51, the three-axis acceleration sensor 52, and the three-axis gyro sensor 53 may be integrated, or may be partially arranged separately. This makes it possible to reduce the number of parts.

[0058] [Additional Notes] The present disclosure is not limited to the above-described embodiments and each modified example, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments and each modified example are also included in the technical scope of the present disclosure.

[0059] [Note] A first aspect of the force information display device includes a signal input unit to which detection signals are input from a force sensor and a gyro sensor arranged between a robot arm and a robot hand, and a control unit, and the control unit executes a first calculation process to calculate a displaced angle of the robot hand from the angular velocity input from the gyro sensor via the signal input unit, and a first display process to convert at least one of the force and moment of a force sensor coordinate system fixed to the force sensor input from the force sensor via the signal input unit based on the displaced angle of the robot hand calculated in the first calculation process, into a force or moment of an absolute coordinate system fixed to the ground and display it on a display, or a second display process to display the relationship between the absolute coordinate system and the force sensor coordinate system on the display based on the displaced angle of the robot hand calculated in the first calculation process.

[0060] According to the first aspect of the force information display device, at least one of the force and moment in the absolute coordinate system, or the relationship between the absolute coordinate system and the force sensor coordinate system, is displayed on the display, allowing the worker to easily grasp the force and moment in the absolute coordinate system acting on the workpiece.

[0061] A second aspect is the force information display device of the first aspect, wherein the control unit, in the second display process, may further display, on the display, an inclination angle of the force sensor coordinate system relative to the absolute coordinate system.

[0062] According to the second aspect of the force information display device, the inclination angle of the force sensor coordinate system relative to the absolute coordinate system is shown on the display, so that the worker can easily understand at what angle the tip of the robot arm is inclined relative to the vertical direction while working.

[0063] A third aspect is a force information display device of the first or second aspect, wherein the control unit, in the second display process, may further display on the display at least one of the force and the moment in the force sensor coordinate system input from the force sensor via the signal input unit.

[0064] According to the third aspect of the force information display device, the worker can easily grasp how much force he is using to press the tip of the robot arm while working, from the force or moment in the force sensor coordinate system acting on the workpiece displayed on the screen.

[0065] A fourth aspect is the force information display device of the third aspect, further comprising an acceleration sensor and a memory unit that pre-stores the mass of the robot hand, and the control unit, in the second display process, may further calculate an inertial force of the robot hand in the force sensor coordinate system from the acceleration input from the acceleration sensor via the signal input unit and the mass of the robot hand, and display a corrected force obtained by subtracting the inertial force from the force in the force sensor coordinate system on the display.

[0066] According to the fourth aspect of the force information display device, the correction force of the force sensor coordinate system acting on the workpiece is displayed on the display, allowing the worker to easily understand the correction force of the force sensor coordinate system acting on the workpiece.

[0067] A fifth aspect is the force information display device of the fourth aspect, wherein the control unit may execute a second calculation process to calculate a mass of a workpiece held by the robot hand based on the correction force, the acceleration in the direction in which the correction force acts detected by the acceleration sensor, and the acceleration of gravity, and a third calculation process to calculate a weight of the workpiece by multiplying the mass of the workpiece by the acceleration of gravity.

[0068] According to the force information display device of the fifth aspect, the weight of the workpiece can be measured while the workpiece is being transported. As a result, the worker can grasp the weight of the workpiece in real time even while the workpiece is being transported.

[0069] A sixth aspect is the force information display device of the first aspect, further comprising an acceleration sensor and a memory unit that pre-stores the mass of the robot hand, and the control unit, in the first display process, further executes a fourth calculation process to calculate an inertial force of the robot hand in the force sensor coordinate system from the acceleration input from the acceleration sensor via the signal input unit and the mass of the robot hand, a fifth calculation process to calculate a correction force by subtracting the inertial force from the force in the force sensor coordinate system, and a first conversion process to convert into a force or moment in the absolute coordinate system based on at least one of the correction force and the moment in the force sensor coordinate system and the displaced angle of the robot hand calculated in the first calculation process, and may display the force or moment in the absolute coordinate system converted in the first conversion process on a display.

[0070] According to the force information display device of the sixth aspect, the force or moment in the absolute coordinate system acting on the workpiece is displayed on the display, allowing the worker to easily grasp the force or moment in the absolute coordinate system acting on the workpiece.

[0071] A seventh aspect is the force information display device of the sixth aspect, wherein the control unit performs a sixth calculation process to calculate a mass of a workpiece held by the robot hand based on the correction force, the acceleration in the direction in which the correction force acts detected by the acceleration sensor, and the acceleration of gravity; and a seventh calculation process to calculate a weight of the workpiece by multiplying the mass of the workpiece by the acceleration of gravity. The following may be executed.

[0072] According to the force information display device of the seventh aspect, the weight of the workpiece can be measured while the workpiece is being transported. As a result, the worker can grasp the weight of the workpiece in real time even while the workpiece is being transported.

[0073] A force information display device of an eighth aspect includes a signal input unit to which detection signals are input from a force sensor, a gyro sensor, and an acceleration sensor arranged between a robot arm and a robot hand, a memory unit that pre-stores the mass of the robot hand, and a control unit, wherein the control unit executes a first calculation process to calculate a displaced angle of the robot hand from the angular velocity input from the gyro sensor via the signal input unit, a second calculation process to calculate an inertial force of the robot hand in a force sensor coordinate system fixed to the force sensor from the acceleration input from the acceleration sensor via the signal input unit and the mass of the robot hand, a third calculation process to calculate a correction force by subtracting the inertial force from the force of the force sensor coordinate system input from the force sensor via the signal input unit, and a conversion process to convert the correction force of the force sensor coordinate system calculated in the third calculation process into a force in an absolute coordinate system fixed to the ground, based on the displaced angle of the robot hand calculated in the first calculation process.

[0074] According to the eighth aspect of the force information display device, the force information display device can calculate the force in the absolute coordinate system acting on the workpiece. As a result, the force information display device can display the force in the absolute coordinate system acting on the workpiece on the display, allowing the worker to easily grasp the force in the absolute coordinate system acting on the workpiece. [Explanation of symbols]

[0075] 10: force information display device, 11: control unit, 14: display, 15: memory unit, 16: signal input unit, 30: robot arm, 40: robot hand, 51: force sensor, 52: 3-axis acceleration sensor, 53: 3-axis gyro sensor, W: work

Claims

1. a signal input unit to which detection signals are input from a force sensor and a gyro sensor disposed between the robot arm and the robot hand; A control unit; Equipped with The control unit is a first calculation process for calculating a displacement angle of the robot hand from the angular velocity input from the gyro sensor via the signal input unit; a first display process for converting at least one of a force and a moment in a force sensor coordinate system fixed to the force sensor, which is input from the force sensor via the signal input unit, based on the displaced angle of the robot hand calculated in the first calculation process, into a force or moment in an absolute coordinate system fixed to the ground, and displaying the force or moment on a display; or a second display process for displaying on the display a relationship between the absolute coordinate system and the force sensor coordinate system based on the displacement angle of the robot hand calculated in the first calculation process; A force information display device that performs the above.

2. The control unit, in the second display process, further displaying on the display an inclination angle of the force sensor coordinate system relative to the absolute coordinate system; The force information display device according to claim 1 .

3. The control unit, in the second display process, further displaying, on the display, at least one of the force and the moment in the force sensor coordinate system input from the force sensor via the signal input unit; The force information display device according to claim 1 .

4. An acceleration sensor; A storage unit that stores the mass of the robot hand in advance, The control unit, in the second display process, further calculating an inertial force of the robot hand in the force sensor coordinate system from the acceleration input from the acceleration sensor via the signal input unit and a mass of the robot hand; a corrected force obtained by subtracting the inertial force from the force in the force sensor coordinate system is displayed on the display. The force information display device according to claim 3 .

5. The control unit is a second calculation process for calculating a mass of a workpiece held by the robot hand based on the corrective force, the acceleration in the direction in which the corrective force acts detected by the acceleration sensor, and the gravitational acceleration; a third calculation process of multiplying the mass of the workpiece by the gravitational acceleration to calculate a weight of the workpiece; Execute The force information display device according to claim 4 .

6. An acceleration sensor; A storage unit that stores the mass of the robot hand in advance, The control unit, in the first display process, further a fourth calculation process for calculating an inertial force of the robot hand in the force sensor coordinate system from the acceleration input from the acceleration sensor via the signal input unit and a mass of the robot hand; a fifth calculation process for calculating a corrective force by subtracting the inertial force from the force in the force sensor coordinate system; a first conversion process for converting the corrective force and / or the moment in the force sensor coordinate system into a force or a moment in the absolute coordinate system based on the displaced angle of the robot hand calculated in the first calculation process; Run displaying on a display the force or moment in the absolute coordinate system transformed by the first transformation process; The force information display device according to claim 1 .

7. The control unit is a sixth calculation process for calculating a mass of a workpiece held by the robot hand based on the correction force, the acceleration in the direction in which the correction force acts detected by the acceleration sensor, and the gravitational acceleration; a seventh calculation process of multiplying the mass of the workpiece by the gravitational acceleration to calculate a weight of the workpiece; Execute The force information display device according to claim 6 .

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