Robots, manufacturing methods, and distributed sensors

Abstract

To improve the accuracy of robot movements. [Solution] A robot having multiple joints, wherein each of the multiple joints, the first joint and the second joint, is equipped with a torque sensor having a first support part, a second support part that faces the first support part and is displaceable relative to the first support part, an elastic part that connects the first support part and the second support part, and a detection part that detects the relative displacement amount between the first support part and the second support part, wherein the number of elastic parts of the torque sensor provided in the first joint is different from the number of elastic parts of the torque sensor provided in the second joint.

Description

Technical Field

[0007]

[0001] The present invention relates to a robot.

Background Art

[0002] In recent years, robot devices have been used in the production lines of various industrial products. In this type of robot device, it is required to accurately perform operations such as assembling workpieces such as flexible objects, lightweight objects, and low-strength members.

[0003] Therefore, in Patent Document 1, as a method for detecting the force acting on a workpiece, a form in which torque detection devices for detecting the torque applied to each joint are arranged at each joint of a robot arm has been proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, it is premised that the same sensors are provided at all joints. However, in a multi-joint robot, since the surrounding environment such as motors and reducers is different for each joint, if the same sensors are provided at all joints, the operation accuracy of the multi-joint robot may deteriorate.

[0006] Therefore, an object of the present invention is to improve the operation accuracy of a robot.

Means for Solving the Problems

[0007] A means for solving the above problem is a robot having a plurality of joints, wherein each of the plurality of joints, the first joint and the second joint, is equipped with a torque sensor having a first support part, a second support part that faces the first support part and is displaceable relative to the first support part, an elastic part that connects the first support part and the second support part, and a detection part that detects the relative displacement amount between the first support part and the second support part, wherein the number of elastic parts of the torque sensor provided in the first joint is different from the number of elastic parts of the torque sensor provided in the second joint. [Effects of the Invention]

[0008] This technology offers advantages in improving the precision of robot movements. [Brief explanation of the drawing]

[0009] [Figure 1] (a) is a diagram showing an example of a torque sensor, and (b) is a magnified view of the detection unit. [Figure 2] This figure shows a robot equipped with a torque sensor. [Figure 3] This is a block diagram of a robot control device. [Figure 4] This is a magnified view of a robot's joint. [Figure 5] This diagram shows a modified example of a torque sensor. [Figure 6] This table shows the characteristics of each joint according to the first embodiment. [Figure 7] This table shows the characteristics of each joint according to the second embodiment. [Figure 8] This table shows the characteristics of each joint according to the third embodiment. [Figure 9] This table shows the characteristics of each joint according to the fourth embodiment. [Figure 10] This table shows the characteristics of each joint according to the fifth embodiment. [Figure 11] This is a diagram showing a distributed torque sensor. [Figure 12]It is a cross-sectional view of a sensor unit related to a distributed torque sensor. [Figure 13] It is a diagram showing the configuration of a distributed torque sensor. [Figure 14] It is a diagram showing a distributed torque sensor in which a sensor unit is arranged. [Figure 15] It is a cross-sectional view of a block elastic body related to a distributed torque sensor. [Figure 16] It is a diagram showing a distributed torque sensor in which a sensor unit and a block elastic body are arranged.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the embodiments described below are merely one embodiment of the invention and are not limited thereto. And, common configurations will be described by referring to a plurality of drawings with each other, and descriptions of configurations with common reference numerals will be omitted as appropriate. For different matters with the same name, they can be distinguished by attaching "the first" and "the second" and so on.

[0011] <First Embodiment> Using FIG. 1, the configuration as an example of a sensor 600 for detecting torque according to the present embodiment will be described.

[0012] The sensor 600 is provided in joints J1 to J6, and includes a detection unit 604 that detects the torque applied to the sensor 600 and a structure 614. The structure 6 can be a structure including a support portion 601, a support portion 602 facing the support portion 601, and an elastic portion 603 connecting the support portions 601 and 602. The structure 614 may be integrally formed or a combination of separate bodies. The sensor 600 does not necessarily have to be provided in all joints J1 to J6, and it may be provided in two or more joints.

[0013] Each part of the structure 614 is made of a predetermined material having an elastic (spring) coefficient according to the target torque detection range and its required resolution, such as a resin or a metal (steel, stainless steel, etc.). A plurality (12 in this example) of elastic parts 603 are arranged along the rotating shaft 613 on which torque acts. The sensor 600 having a desired elastic (spring) coefficient can be configured by the number, shape (thickness), and material of the elastic parts 603. The structure 614 may be manufactured by a 3D printer. Specifically, slice data, which is data for a 3D printer, may be created from the design data (e.g., CAD data) of the structure 614, and the structure 614 may be manufactured by inputting the data into a conventional 3D printer.

[0014] Four detection parts 604 are arranged at approximately 90° intervals. In this embodiment, there are four detection parts 604, but there may be one or a plurality, and it is sufficient to have one or more.

[0015] FIG. 1(b) shows a cross-sectional view of the detection part 604 provided in the sensor 600. The detection substrate 610 provided with the detection head 611 is adhesively supported (double-sided tape is also acceptable) by a stay 609 for fixing the detection substrate 610. The stay 609 is adhesively supported by the support part 601. A scale 612 that reflects light emitted from the detection head 611 is adhesively supported by the support part 602.

[0016] The detection substrate 610 has a function as an optical position sensor (encoder). Further, the detection head 611 is composed of a reflection-type optical sensor provided with a light-emitting element and a light-receiving element (not shown). On the pattern surface of the scale 612 facing the detection head 611, a scale pattern (details not shown) is arranged on the surface. This scale pattern is configured, for example, by regularly varying the shading or reflectivity in a specific pattern.

[0017] The detection head 611 emits light from a light-emitting element onto the scale 612, and the light reflected from the scale 612 is received by a photodetector. When a torque is applied around the rotation axis 613 and the structure 614 deforms in the x-axis direction, the relative position of the detection head 611 and the scale 612 changes, causing the irradiation position of the light illuminating the scale 612 to move across the scale 612. When the light illuminating the scale 612 passes through a pattern provided on the scale 612, the amount of light detected by the photodetector of the detection head 611 changes. From this change in light amount, the relative displacement between the scale 612 and the detection head 611 is detected. The displacement detected by the detection head 611 is converted into the torque acting on the structure 614 by a torque detection control unit configured by a control routine executed by the control device 300.

[0018] In this embodiment, as shown in Figure 1, two detection units 604 are arranged at opposing positions on the same diameter with respect to the rotation axis 613. In this case, the torque detection values ​​output from the detection head 611 are averaged and calculated. This reduces the influence of forces acting in directions other than the target torque detection direction.

[0019] Furthermore, detection values ​​related to relative displacement are obtained from detection units 604 positioned at symmetrical positions on a line or point on the same diameter centered on the rotation axis 613. Therefore, by averaging the outputs of multiple detection units 604, highly accurate and reliable relative displacement information, or torque detection values ​​based thereon, can be obtained. Since torque detection values ​​are obtained by averaging in this way, the accuracy can be improved by increasing the number of detection units 604. On the other hand, the cost increases as the number of detection units 604 increases, so it is necessary to optimize the number of detection units 604 to suit the torque of each joint J1 to J6.

[0020] Next, using Figure 2, we will describe the robot device 100 according to this embodiment, which is equipped with the sensor 600 described above.

[0021] The robotic device 100 includes a robotic arm (robot) 200 as a multi-joint robot, a control device 300 that controls the robotic arm 200, and a teaching pendant 400. The teaching pendant 400 is a teaching device that transmits data of multiple teaching points to the control device 300 and is used by the operator to specify the movements of the robotic arm 200.

[0022] In this embodiment, the robot arm 200 is a six-joint robot, but it may have any number of joints. The robot arm 200 has multiple servo motors 201 to 206 that rotate each joint J1 to J6 around each joint axis A1 to A6. Within its range of motion, the robot arm 200 can orient its tip to any three directions at any three-dimensional position. Generally, the position and orientation of the robot arm 200 can be expressed in coordinate systems. To represents the coordinate system fixed to the base 250 of the robot arm 200, and Te represents the coordinate system fixed to the end effector of the robot arm 200.

[0023] In this embodiment, each servo motor 201 to 206 comprises an electric motor 211 to 216 and sensor units 221 to 226 connected to the electric motors 211 to 216. Each sensor unit 221 to 226 includes an angle sensor for detecting the angle of each joint J1 to J6 and a sensor 600 capable of detecting the torque of each joint J1 to J6. Each servo motor 201 to 206 is connected to a frame driven by its respective joint J1 to J6.

[0024] The robot arm 200 further includes a servo control unit 230, which acts as a drive control unit for driving and controlling the electric motors 211 to 216 of each servo motor 201 to 206. Based on the input torque command value, the servo control unit 230 outputs a current command to each electric motor 211 to 216 so that the torque of each joint J1 to J6 follows the command torque, thereby controlling the operation of each electric motor 211 to 216. In this embodiment, the servo control unit 230 is described as being composed of a single control device, but it is also possible to have separate servo control units corresponding to each electric motor 211 to 216.

[0025] The robot arm 200 can be fitted with a hand at its tip, for example, to grip a workpiece. Using the attached hand, it can perform tasks that manufacture goods, such as gripping a workpiece and assembling the gripped workpiece with another workpiece to manufacture an item. In addition, a screwdriver can be attached to the tip to fasten screws on a workpiece, and the robot arm 200 can primarily perform workpiece processing tasks at its tip. Here, processing includes tasks such as gripping and moving a workpiece. Furthermore, it is possible to work collaboratively even when an operator is nearby.

[0026] Next, the general configuration of the control device 300 will be explained with reference to Figure 3. The control device 300 includes an arithmetic unit 301 as a control unit. The arithmetic unit 301 is a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array). The control device 300 also includes a main memory 303, such as a ROM (Read Only Memory) 302 and RAM (Random Access Memory), as storage units. The ROM 302 stores a program 330 for operating the arithmetic unit 301, such as a BIOS. The main memory 303 is a storage device that temporarily stores various data, such as the results of the arithmetic processing of the arithmetic unit 301. The control device 300 also includes an auxiliary storage device 304, such as an HDD (Hard Disk Drive) or SSD (Solid State Drive), as storage units. The auxiliary storage device 304 stores the results of the arithmetic processing of the arithmetic unit 301 and data acquired from external sources. In addition, the control device 300 includes a recording disk drive (recording medium) 305 and various interfaces 306 to 309.

[0027] The arithmetic unit 301 is connected to a ROM 302, a main memory 303, an auxiliary memory 304, a recording disk drive 305, and various interfaces 306 to 309 via a bus 310.

[0028] The teaching pendant 400 is connected to interface 306, and the arithmetic unit 301 receives teaching point data from the teaching pendant 400 via interface 306 and bus 310.

[0029] Monitor 321 is connected to interface 307, and various images are displayed on Monitor 321.

[0030] The external storage device 322 is connected to the interface 308, and the external storage device 322 may be a rewritable non-volatile memory or an external HDD.

[0031] The servo control unit 230 is connected to the interface 309, and the calculation unit 301 outputs target torque data for each joint J1 to J6 to the servo control unit 230 via the bus 310 and interface 309 at predetermined time intervals.

[0032] The recording disk drive 305 can read various data and programs recorded on the recording disk (recording medium) 331. Note that the recording medium on which the program according to the present invention is recorded is not limited to the recording disk 331, but also includes non-volatile memory such as the external storage device 322 and external HDDs.

[0033] Figure 4 shows enlarged views of each joint J1 to J6 where the sensor 600 is installed.

[0034] The sensor 600 is connected to the gearbox 1101 via the sensor mounting section 1103, and the gearbox 1101 is connected to the servo motors 201 to 206.

[0035] The sensor 600's structure 614 undergoes elliptical deformation due to the rotational vibrations of the servo motors 201-206 and the connected reduction gear 1011. When the structure 614 deforms elliptically, the stay 609 deforms, causing the detection head 611 to displace, which may result in false torque detection. Therefore, the more easily the deformation of the reduction gear 1011 is transmitted to the sensor 600, the stronger the impact becomes.

[0036] In other words, the lower the rigidity of the reducer 1011 or the sensor mounting section 1103, the more likely it is to occur. Therefore, the lower the rigidity of the reducer 1011 or the sensor mounting section 1103, the more the number of detection sections 604 of the sensor 600 can be increased to mitigate false torque detection when elliptical deformation occurs. This makes it possible to detect torque with high accuracy at each joint J1 to J6.

[0037] At this time, servo motors 201 to 206 or a reduction gear 1011 suitable for each joint J1 to J6 are used. For example, different ratings are used for the servo motors 201 to 206 or the reduction gear 1011 between joints. Since the control device 300 controls force or position based on the servo motors 201 to 206 of each joint J1 to J6, it is preferable that the sensor 600 covers the rating range of the servo motors 201 to 206. On the other hand, if the rating range of the sensor 600 is made too large, there is a risk that the necessary resolution cannot be obtained. Therefore, by making the sensors 600 mounted on each joint J1 to J6 have a rigidity suitable for each joint J1 to J6, it is possible to improve the operational accuracy of the robot arm 200.

[0038] Furthermore, the distance between the reducer 1011 and the sensor 600 influences how easily the deformation of the reducer 1011 is transmitted to the sensor 600. Depending on the design of the joints J1 to J6 of the robot arm 200, the installation distance between the reducer 1011 and the sensor 600 may be close or far. When the distance is close, the influence of the deformation of the reducer 1011 on the sensor 600 becomes stronger.

[0039] Therefore, in this embodiment, the number of detection units 604 is adjusted according to the rigidity of the reduction gear 1011, the rigidity of the torque sensor mounting section 1103, and the difference in distance between the reduction gear 1101 and the torque sensor. By equipping each joint J1 to J6 with a sensor 600 suitable for that joint, we can provide a robot arm with improved operational accuracy.

[0040] For example, if the distance between the gearbox 1011 and the sensor 600 is short, the operating accuracy of the robot arm 200 can be maintained by increasing the number of detection units 604.

[0041] Furthermore, the sensors 600 mounted on each joint J1 to J6 of the robot arm 200 require torque detection accuracy in addition to the rigidity mentioned above. While a higher number of detection units 604 results in higher accuracy due to the averaging effect, it is desirable to use an appropriate number of detection units 604 for each joint J1 to J6, taking into account the balance of cost, size, etc.

[0042] For example, if the torque sensor is located in a joint that is less susceptible to forces in other axes, one detection unit 604 may suffice. However, if the torque sensor is located in a joint that is strongly affected by the deformation of the speed reducer, four or more detection units 604 are preferable.

[0043] Next, using Figure 5, we will describe a sensor 600 with a different structure from the sensor 600 shown in Figure 1, which is one of the sensors 600 according to this embodiment.

[0044] The sensor 600 in Figure 5 differs from the sensor 600 in Figure 1 in that the number of detection units 604 has been changed from 4 to 2, and the number of elastic units 603 has been changed from 12 to 8.

[0045] In this embodiment, the sensor 600 has reduced rigidity and improved resolution by decreasing the number of elastic parts 603. This makes it possible to provide a sensor 600 with rigidity suitable for each joint J1 to J6, thereby improving the operational accuracy of the robot arm 200. Furthermore, if the thickness and material of the elastic parts 603 are common to each joint J1 to J6, it is possible to easily provide a sensor 600 with rigidity suitable for each joint J1 to J6. Another way to reduce rigidity is to reduce the size of the sensor 600.

[0046] As described above, the higher the rated output of the servo motors 201-206 or the gearbox 1011 mounted on each joint J1-J6, the more elastic parts 603 of the sensor 600 are required. Furthermore, the lower the rated output of the servo motors 201-206 or the gearbox 1011 mounted on each joint J1-J6, the fewer elastic parts 603 of the sensor 600 are required. This shortens the design time for the sensor 600 and allows for the provision of a sensor 600 suitable for each joint J1-J6.

[0047] Furthermore, the servo motors 201 to 206 mounted on each joint J1 to J6 of the robot arm 200 become smaller as they approach the tip of the robot arm 200. Consequently, the rigidity required of the sensor 600 also decreases. Therefore, it is preferable that the number of elastic parts 603 of the sensor 600 be smaller for sensors 600 located at the tip of the robot arm 200. In other words, it is preferable that the number of elastic parts 603 of the sensor 600 is greater for joints closer to the base 250 than for joints at the tip of the robot arm 200.

[0048] For example, as shown in Figure 6, the sensor 600 mounted on J1 of the robot arm 200 has 12 elastic parts 603, while the sensors 600 mounted on J2 and J3 have 8 to 12 elastic parts 603. For example, the sensors 600 mounted on J4 and J5 have 4 to 8 elastic parts 603, and the sensor 600 mounted on J6 has 4 elastic parts 603, so the difference in the number of elastic parts 603 in each joint J1 to J6 is within 8.

[0049] Furthermore, the sensor 600 mounted on J1 of the robot arm 200 has 8 detection units 604, and the sensors 600 mounted on J2 and J3 have 4 to 8 elastic units 603. For example, the sensors 600 mounted on J4 and J5 have 2 to 4 elastic units 603, and the sensor 600 mounted on J6 has 1 elastic unit 603, so the difference in the number of elastic units 603 in each joint J1 to J6 is within 7.

[0050] By improving the resolution and precision of joint J6 of the robot arm 200 compared to the other joints J1 to J5, the robot arm 200 can operate with high precision relative to the workpiece.

[0051] For example, the first joint described in the claims is not limited to joint J1, but may be any of joints J1 to J6. Similarly, the nth joint described in the claims may be any of joints J1 to J6.

[0052] <Second Embodiment> Next, the configuration of each joint J1 to J6 of the robot arm 200 according to this embodiment will be described using Figure 7. In this embodiment, the number of elastic parts 603 and the number of detection parts 604 in each joint J1 to J6 are different from those in the first embodiment.

[0053] The robot arm 200's rigidity is increased by increasing the number of elastic parts 603 in joint J6. This allows the robot arm 200 to be used without problems even in tasks where the resolution and precision of joint J6 are not required, and also helps to suppress cost increases.

[0054] <Third Embodiment> Next, the configuration of each joint J1 to J6 of the robot arm 200 according to this embodiment will be described using Figure 8. In this embodiment, the number of elastic parts 603 and the number of detection parts 604 in each joint J1 to J6 are different from those in the first and second embodiments.

[0055] The number of elastic parts 603 and detection parts 604 in the joints J2 to J5 of the robot arm 200 are alternately varied. As in this embodiment, it is also possible to reduce the rigidity of the joints in which resolution and accuracy are to be improved.

[0056] <Fourth Embodiment> Next, the configuration of each joint J1 to J6 of the robot arm 200 according to this embodiment will be described using Figure 9. In this embodiment, the number of elastic parts 603 and the number of detection parts 604 in each joint J1 to J6 are different from those in the first to third embodiments.

[0057] In this embodiment, the number of elastic parts 603 and detection parts 604 is increased in the order of joints J1 to J6 of the robot arm 200. This makes it possible to apply this method even to the robot arm 200 where it is desired to improve the resolution and accuracy of joint J1 the most.

[0058] In addition to the first to fourth embodiments, the elastic portion 603 and detection portion 604 of each joint J1 to J6 can be arbitrarily set according to the desired performance.

[0059] <Fifth Embodiment> Next, using Figure 10, we will explain the case where the robot arm 200 has three joints (joint A, joint B, and joint C). Joint A is on the base 250 side, and joint C is the joint at the tip of the robot arm 200.

[0060] In this embodiment, the stiffness of joints A to C varies. For example, in the top table of Figure 10, the stiffness decreases in the order of joint A, joint B, and joint C. In contrast, in the bottom table of Figure 10, the stiffness increases in the order of joint A, joint B, and joint C.

[0061] As shown in the other tables, the magnitude of stiffness can be determined by rearranging joints A, B, and C in any order.

[0062] In this embodiment, we will describe the case of three joints A to C, but it may also be two joints or four or more joints.

[0063] <Sixth Embodiment> Next, the sensor 600 according to this embodiment will be described using Figures 11 to 16.

[0064] The sensor 600 according to this embodiment differs from the sensor 600 according to the first embodiment in that the sensor unit 804 equipped with a detection unit is configured separately, and the elastic part 603 is dispersed, making it a distributed type sensor 800.

[0065] The distributed sensor 800 comprises multiple sensor units 804. It is preferable that the multiple sensor units 804 are arranged facing each other.

[0066] Figure 12 shows the configuration of the sensor unit 804. The sensor unit 804 includes a detection substrate 910, a detection head 911, and a scale 912, similar to the detection unit 604 of the first embodiment. In this embodiment, the stay 906 supports the scale 912, but it may also support the detection head 911. The sensor unit 804 includes a support part 601, a support part 602, and a pair of elastic parts 903, and the displacement of the elastic parts 903 is detected by the detection head 911 and the scale 912.

[0067] When mounting distributed sensors 800 on each joint J1 to J6 of the robot arm 200, link members 801 and 802 can be used, for example, as shown in Figure 13. The link members 801 and 802 each have positioning portions 1001 and 1002 for fitting with the sensor unit 804.

[0068] Figure 14 is a top view of a distributed sensor 800 equipped with eight sensor units 804. By adjusting the number of sensor units 804 according to the desired rigidity and resolution, a distributed sensor 800 suitable for each joint J1 to J6 can be easily arranged. The sensor units 804 have a recess in the center, but they do not all need to be the same shape; different shaped sensor units 804 can be used for each joint J1 to J6. Also, the distance from the rotation axis 813 to each sensor unit 804 does not need to be the same; the distance can be varied according to the wiring path. For similar reasons, it is also possible to offset each sensor unit 804 in the Z direction, i.e., not to arrange them on the same plane.

[0069] Figure 15 shows the block elastic body 900, which is the sensor unit 804 with the detection section removed. Unlike the sensor unit 804 described above, the block elastic body 900 is configured in a way that prevents it from detecting torque.

[0070] The sensor unit 804 and the elastic body 900 can be fixed to the link members 801 and 802, for example, with screws, and can be easily removed and replaced.

[0071] Figure 16 is a top view of a distributed sensor 800 consisting of two block elastic bodies 900 and six sensor units 804. The distributed sensor 800 includes block elastic bodies 900 as non-detection parts that do not detect torque. This eliminates the need to change the number of positioning parts 1001 and 1002 of the link members 801 and 802 by adjusting the number of sensor units 804, and allows for adjustment of rigidity and resolution. Therefore, distributed sensors 800 suitable for each joint J1 to J6 can be easily arranged while maintaining the operational accuracy of the robot arm 200. For example, the weight of the tip of the robot arm 200 can be reduced by changing the thickness or height of the sensor unit 804 or the elastic part 903 of the block elastic body 900 at joint J6.

[0072] The embodiments described above can be modified as appropriate without departing from the technical concept.

[0073] For example, multiple embodiments can be combined. Furthermore, some elements of at least one embodiment can be deleted or replaced.

[0074] Furthermore, new matters may be added to at least one embodiment. The disclosures of this specification include not only those explicitly stated herein, but also all matters that can be understood from this specification and the accompanying drawings.

[0075] Furthermore, the disclosures in this specification include the complements of the individual concepts described herein. That is, if this specification contains a statement such as "A is greater than B," then even if it omits a statement such as "A is not greater than B," it can be said that this specification discloses "A is not greater than B." This is because the statement "A is greater than B" presupposes that the case where "A is not greater than B" is being considered. [Explanation of Symbols]

[0076] 200 Articulated Robots 601 1st support part 602 Second support part 603, 903 Elastic part 604 Detection Unit 600, 800 Torque Sensor J1-J6 joints

Claims

1. A robot having multiple joints, Of the aforementioned multiple joints, the first joint and the second joint are, The device comprises a first support portion, a second support portion facing the first support portion and capable of relative displacement with respect to the first support portion, an elastic portion connecting the first support portion and the second support portion, and a torque sensor having a detection portion for detecting the relative displacement amount between the first support portion and the second support portion. The number of elastic parts of the torque sensor provided in the first joint is: A robot characterized in that the number of elastic parts of the torque sensor provided in the second joint is different from the number of elastic parts of the second joint.

2. The robot according to claim 1, characterized in that the number of detection units in the first joint is different from the number of detection units in the second joint.

3. A robot having multiple joints, Of the aforementioned multiple joints, the first joint and the second joint are, The device comprises a first support portion, a second support portion facing the first support portion and capable of relative displacement with respect to the first support portion, an elastic portion connecting the first support portion and the second support portion, and a torque sensor having a detection portion for detecting the relative displacement amount between the first support portion and the second support portion. The number of detection units of the torque sensor provided in the first joint is A robot characterized in that the number of detection units of the torque sensor provided in the second joint is different from the number of detection units of the second joint.

4. The rated output of the motor installed in the first joint is less than the rated output of the motor installed in the second joint. The robot according to any one of claims 1 to 3, characterized in that the number of elastic parts of the first joint is less than the number of elastic parts of the second joint.

5. The rated output of the reduction gear installed at the first joint is less than the rated output of the reduction gear installed at the second joint. The robot according to any one of claims 1 to 4, characterized in that the number of elastic parts of the first joint is less than the number of elastic parts of the second joint.

6. The robot is fixed to a base, The robot according to any one of claims 1 to 3, characterized in that, among the plurality of joints, the third joint has fewer elastic parts than the fourth joint, which is a joint on the base side than the third joint.

7. The robot according to any one of claims 1 to 3, characterized in that, among the plurality of joints, the number of elastic parts of the fifth joint is greater than the number of elastic parts of the sixth joint, which is a joint on the tip end side of the robot than the fifth joint.

8. Of the aforementioned multiple joints, the seventh joint and the eighth joint, which is different from the seventh joint, are equipped with a reduction gear. The rigidity of the reduction gear installed at the seventh joint is greater than the rigidity of the reduction gear installed at the eighth joint. The robot according to any one of claims 1 to 3, characterized in that the number of detection units in the seventh joint is less than the number of detection units in the eighth joint.

9. Of the aforementioned multiple joints, the ninth joint and the tenth joint, which is different from the ninth joint, are provided with a torque sensor mounting portion for attaching the torque sensor. The rigidity of the torque sensor mounting portion installed at the ninth joint is greater than the rigidity of the torque sensor mounting portion installed at the tenth joint. The robot according to any one of claims 1 to 3, characterized in that the number of detection units in the ninth joint is less than the number of detection units in the tenth joint.

10. Of the aforementioned plurality of joints, the 11th joint and the 12th joint, which is different from the 11th joint, are equipped with a torque sensor mounting portion for attaching the reduction gear and the torque sensor. The sum of the rigidity of the reduction gear installed at the 11th joint and the rigidity of the torque sensor mounting part installed at the 11th joint is greater than the sum of the rigidity of the reduction gear installed at the 12th joint and the rigidity of the torque sensor mounting part installed at the 12th joint. The robot according to any one of claims 1 to 3, characterized in that the number of detection units in the 11th joint is less than the number of detection units in the 12th joint.

11. Of the aforementioned multiple joints, the 13th joint and the 14th joint, which is different from the 13th joint, are equipped with a reduction gear and a torque sensor. The distance between the reduction gear and the torque sensor at the 13th joint is greater than the distance between the reduction gear and the torque sensor at the 14th joint. The robot according to any one of claims 1 to 3, characterized in that the number of detection units in the 13th joint is less than the number of detection units in the 14th joint.

12. The torque sensor comprises a plurality of sensor units, each consisting of a pair of elastic parts and a detection part, wherein each of the plurality of sensor units is formed separately, and the number of sensor units differs between the 15th joint and the 16th joint, which is different from the 15th joint, among the plurality of joints, as described in any one of claims 1 to 3.

13. The robot according to claim 12, characterized in that the sensor unit of the 15th joint and the sensor unit of the 16th joint have the same shape.

14. The robot according to claim 12, characterized in that the sensor unit of the 15th joint and the sensor unit of the 16th joint have different thicknesses of the elastic portion.

15. The robot according to any one of claims 12 to 14, wherein the torque sensor comprises an elastic body having a pair of elastic parts, the elastic body being a non-detection part that does not detect the amount of displacement, and the elastic body having a different thickness from the sensor unit and the elastic parts.

16. The robot according to claim 15, wherein the torque sensor comprises a first structural part and a second structural part facing the first structural part, and the elastic body, the first structural part and the second structural part are fitted together.

17. The robot according to any one of claims 12 to 16, characterized in that the torque sensor comprises a first structural part and a second structural part facing the first structural part, and the sensor unit, the first structural part and the second structural part are fitted together.

18. The robot according to any one of claims 1 to 3, characterized in that, among the plurality of joints, the difference between the number of elastic parts in the 17th joint and the number of elastic parts in the 18th joint, which is different from the 17th joint, is 8 or less.

19. The robot according to any one of claims 1 to 3, characterized in that, among the plurality of joints, the difference between the number of detection units in the 19th joint and the number of detection units in the 20th joint, which is different from the 19th joint, is 7 or less.

20. The robot according to any one of claims 1 to 19, characterized in that the detection unit comprises a detection head and a scale facing the detection head.

21. The robot according to any one of claims 1 to 20, characterized in that the elastic portion connects the first support portion and the second support portion in a direction along the axis of rotation of the second support portion with respect to the first support portion.

22. A method for manufacturing an article produced by a robot according to any one of claims 1 to 21, characterized in that the robot grips or processes a workpiece with its tip portion.

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