Driving device, robot, control method, detection device, article manufacturing method, processing method, program, and recording medium

Abstract

To provide a joint device equipped with a speed reducer that is used as a joint of a robot or the like, which can detect output-side torque and a rotation angle with high accuracy, and yet can be downsized.SOLUTION: A joint device comprises a motor and a speed reducer respectively fixed to fixing members, a support member, and an output member. An output shaft of the motor is joined to an input shaft of the speed reducer, an output shaft of the speed reducer is joined to the support member, and the support member is joined to the output member through an elastic body. To the fixing member are fixed either of a scale and a sensor for measuring a rotation angle of the output shaft of the speed reducer with respect to the fixing member and either of a scale and a sensor for measuring a rotation angle of the output member with respect to the fixing member. To the support member is fixed the other of the scale and the sensor for measuring the rotation angle of the speed reducer with respect to the fixing member. To the output member is fixed the other of the scale and the sensor for measuring the rotation angle of the output member with respect to the fixing member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joint device used in a robot arm of an articulated robot, etc. In particular, the present invention relates to a joint device equipped with a reducer and a sensor for measuring torque and angle on the output side of the reducer. [Background technology]

[0002] Conventionally, in joint devices used in rotary joints of articulated robots and the like, the rotation of a motor is reduced by a reducer and transmitted to an output shaft, causing the output shaft to rotate. To control the rotation of the output shaft, it is common to measure the output of an encoder attached to the rotating shaft of the motor or the current flowing through the motor, and feed this back to the motor drive. However, this method is affected by the frictional force, viscous force, backlash, and rattle of the reducer, making it difficult to control the rotation of the output shaft with high precision.

[0003] Therefore, a control method has been attempted in which, in addition to measuring the angle of the motor's rotating shaft and the current flowing through the motor, the angle on the output side of the reducer and the torque transmitted to the output shaft are measured and fed back to the motor. For example, Patent Document 1 discloses a joint device equipped with both a torque sensor and an encoder on the output side of a reducer. The rotating shaft of a motor is connected to the input shaft of the reducer to transmit the rotation of the motor to the reducer, and the flexspline on the output side of the reducer is connected to the output shaft. A motor control encoder is provided on the rotating shaft of the motor, and an output shaft encoder and a torque sensor are provided on the output shaft of the reducer.

[0004] The motor control encoder detects the rotation of the motor shaft, and the output shaft encoder detects the rotation angle of the reducer output shaft. The torque sensor attached to the reducer output shaft measures the magnetic resistance of the sensor film and converts it into torque, thereby detecting the torsional torque generated on the reducer output shaft due to the reaction force from the load. The detection signals detected by these sensors are then fed back to the motor driver. This technique reduces the reduction in control accuracy of the output shaft due to backlash and other play in the reducer and hysteresis characteristics. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-50710 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the joint device described in Patent Document 1 has problems in terms of the detection accuracy of the sensor and the size of the device, as will be described below. (1) The accuracy of the torque sensor cannot be increased. Although strain gauges and magnetostrictive torque sensors are known, it is difficult to increase the dynamic range, or the ratio of resolution to measurement range, with these sensors. In other words, increasing the measurement range results in a decrease in resolution. When applied to an articulated robot, a large torque is applied to the base joint in order to support the arm's own weight and the weight of the load being carried. For example, even a small robot with a total length of 500 mm generally experiences a torque of about 50 Nm. With torque sensors that use strain gauges or magnetostrictive effects, even if a dynamic range of, say, 1000 levels can be set, a resolution of only 50 mNm can be ensured. For this reason, even with such torque sensors, it is difficult to achieve high-precision force control of an articulated robot, limiting its practical performance.

[0007] (2) High-precision torque sensors are difficult to miniaturize and are expensive. It is possible to use a torque sensor that utilizes the deformation of an elastic body instead of a strain gauge, but the elastic body must be flexible only in the direction of the torque to be detected and rigid in other directional components, i.e., it must have a shape with a high rigidity ratio. A design with a large number of structural design parameters is advantageous for increasing the rigidity ratio, but a structural design with a large number of parameters generally results in a complex shape of the elastic body, making miniaturization difficult. Furthermore, a complex shape increases manufacturing costs, and in some cases, it may be difficult to achieve using common processing methods such as machining.

[0008] In view of the above, there has been a desire to realize a joint device equipped with a reducer that is capable of detecting the torque and rotation angle on the output side with high accuracy and that is also small in size. [Means for solving the problem]

[0009] One aspect of the present invention is a drive device comprising: a motor provided on a fixed member; a support member driven by the motor and movable relative to the fixed member; and an output member connected to the support member by an elastic body and movable relative to the support member, wherein the fixed member or the support member has a first scale on one side and a first sensor on the other side, the fixed member or the output member has a second scale on one side and a second sensor on the other side, and the fixed member, the support member, and the output member Based on a plate is provided, Before The first sensor and before The second sensor Toga It is provided, before The first sensor is disposed so as to face the first scale. On the substrate the second sensor is provided so as to face the second scale. On the substrate It is established, the first sensor and the second sensor are provided on a surface of the substrate facing the first scale and the second scale, This is a driving device characterized in that the relative displacement between the fixed member and the support member is obtained using the first scale and the first sensor, and the relative displacement between the fixed member and the output member is obtained using the second scale and the second sensor. Another aspect of the present invention is a motor provided on a fixed member; a reducer that reduces the speed of the motor; The motor and the reducer an output member driven by the drive shaft and moving relative to the fixed member; The reducer is provided The fixing member is connected to the elastic member. Ta and a support member movable relative to the fixed member, wherein the fixed member or the output member has a first scale on one side and a first sensor on the other side, the support member or the output member has a second scale on one side and a second sensor on the other side, and the output member, or the fixed member and the support member Based on a plate is provided, Before The first sensor and before The second sensor Toga It is provided ,before The first sensor is disposed so as to face the first scale. On the substrate the second sensor is provided so as to face the second scale. On the substrate a driving device including: a driving mechanism for driving a fixed member and an output member; a driving mechanism for driving a fixed member and an output member; a driving mechanism for driving a fixed member and an output member; is .

[0010] Another aspect of the present invention is a control method for a drive device including a motor provided on a fixed member, a support member driven by the motor and movable relative to the fixed member, an output member connected to the support member by an elastic body and movable relative to the support member, and a control unit, wherein a first scale is provided on one of the fixed member or the support member and a first sensor is provided on the other, a second scale is provided on one of the fixed member or the output member and a second sensor is provided on the other, and a substrate is provided on the fixed member, the support member, and the output member. the first sensor and the second sensor are provided on the substrate, the first sensor is provided on the substrate so as to face the first scale, the second sensor is provided on the substrate so as to face the second scale, the first sensor and the second sensor are provided on surfaces of the substrate facing the first scale and the second scale, and the control unit acquires a relative displacement between the fixed member and the support member using the first scale and the first sensor, and acquires a relative displacement between the fixed member and the output member using the second scale and the second sensor. death and controlling the motor based on the acquired results. Another aspect of the present invention is a control method for a drive device including a motor provided on a fixed member, a reducer that reduces the speed of the motor, an output member that is driven by the motor and the reducer and moves relative to the fixed member, a support member that is provided on the reducer and connected to the fixed member by an elastic body and is movable relative to the fixed member, and a control unit, wherein either the fixed member or the output member has a first scale provided on one side and a first sensor provided on the other side, and either the support member or the output member has a second scale provided on one side and a second sensor provided on the other side, a substrate is provided on the output member, or on the fixed member and the support member, the first sensor and the second sensor are provided on the substrate, the first sensor is provided on the substrate so as to face the first scale, and the second sensor is provided on the substrate so as to face the second scale; the first scale and the first sensor are used to obtain a relative displacement between the fixed member and the output member, and the second scale and the second sensor are used to obtain a relative displacement between the output member and the support member; and the motor is controlled based on the obtained results.

[0011] Another aspect of the present invention is a method for detecting information about a torque of an output member that moves when driven by a motor and outputs torque. Testa processing unit; a fixed member on which the motor is mounted; a support member driven by the motor and movable relative to the fixed member; an output member connected to the support member by an elastic body and movable relative to the support member; and a processing unit; wherein the fixed member or the support member has a first scale mounted on one side and a first sensor mounted on the other side, the fixed member or the output member has a second scale mounted on one side and a second sensor mounted on the other side, and the fixed member or the support member and the output member are provided with a substrate, and the first sensor and the second sensor are mounted on the substrate. the first sensor is provided on the substrate so as to face the first scale, the second sensor is provided on the substrate so as to face the second scale, the first sensor and the second sensor are provided on the surface of the substrate facing the first scale and the second scale, and the processing unit acquires the relative displacement between the fixed member and the support member using the first scale and the first sensor, acquires the relative displacement between the fixed member and the output member using the second scale and the second sensor, and acquires information about the torque based on the acquired results. Another aspect of the present invention is a device for detecting information about torque in an output member that moves by driving a motor and a reducer that reduces the speed of the motor and outputs torque. Test the detection device includes a fixed member on which the motor is provided, an output member driven by the motor and the reducer and moving relative to the fixed member, a support member provided on the reducer and connected to the fixed member by an elastic body and movable relative to the fixed member, and a processing unit, and the fixed member or the output The member has a first scale on one side and a first sensor on the other side, support a second scale is provided on one side of the member or the output member, and a second sensor is provided on the other side of the member or the output member; The aforementioned output member, or the above fixed member and supporta substrate is provided on a member, the first sensor and the second sensor are provided on the substrate, the first sensor is provided on the substrate so as to face the first scale, the second sensor is provided on the substrate so as to face the second scale, and the processing unit detects the relationship between the fixed member and the output and obtains a relative displacement between the object and the second sensor using the second scale and the second sensor. output The member and support This is a detection device characterized by obtaining a relative displacement with respect to a member, and obtaining information about the torque based on the obtained result.

[0012] Another aspect of the present invention is a method for detecting information about a torque of an output member that moves when driven by a motor and outputs torque. Test a processing method for an output device, the detection device comprising: a fixed member on which the motor is provided; a support member driven by the motor and movable relative to the fixed member; an output member connected to the support member by an elastic body and movable relative to the support member; and a processing unit, wherein a first scale is provided on one side of the fixed member or the support member and a first sensor is provided on the other side of the fixed member or the output member; a second scale is provided on one side of the fixed member or the output member and a second sensor is provided on the other side of the fixed member or the support member and a substrate is provided on the fixed member or the support member and the output member, the first sensor and the second sensor are provided on the substrate, the first sensor is provided on the substrate so as to face the first scale, the second sensor is provided on the substrate so as to face the second scale, and the first sensor and the second sensor are provided on surfaces of the substrate facing the first scale and the second scale, The processing method is characterized in that the processing unit acquires the relative displacement between the fixed member and the support member using the first scale and the first sensor, acquires the relative displacement between the fixed member and the output member using the second scale and the second sensor, and acquires information about the torque based on the acquired results. Another aspect of the present invention is a device for detecting information about torque in an output member that moves by driving a motor and a reducer that reduces the speed of the motor and outputs torque. Test a processing method for an output device, the detection device comprising: a fixed member on which the motor is provided; an output member driven by the motor and the reducer and movable relative to the fixed member; a support member provided on the reducer and connected to the fixed member by an elastic body and movable relative to the fixed member; and a processing unit, output The member has a first scale on one side and a first sensor on the other side, support a second scale is provided on one side of the member or the output member, and a second sensor is provided on the other side of the member or the output member; output member, or the above fixed member and support a substrate is provided on a member, the first sensor and the second sensor are provided on the substrate, the first sensor is provided on the substrate so as to face the first scale, the second sensor is provided on the substrate so as to face the second scale, and the processing unit detects the relationship between the fixed member and the output and obtains a relative displacement between the object and the second sensor using the second scale and the second sensor. output The member and support This is a processing method characterized by obtaining a relative displacement with respect to a member, and obtaining information about the torque based on the obtained result. [Effects of the Invention]

[0013] The present invention can provide a small-sized joint device that includes a reducer and is capable of detecting the torque and rotation angle on the output side with high accuracy. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a joint device according to a first embodiment. [Figure 2] FIG. 1 is a cross-sectional view showing the configuration of a joint device of Example 1 according to Embodiment 1. [Figure 3] 10A to 10C are diagrams showing the arrangement of elastic bodies in Examples 1 to 4. [Figure 4] FIG. 10 is a diagram showing the arrangement of sensors and scales in the first and third embodiments. [Figure 5] FIG. 10 is a cross-sectional view showing the configuration of a joint device of Example 2 according to Embodiment 1. [Figure 6] 10A and 10B are diagrams showing the arrangement of sensors and scales in the second and fourth embodiments. [Figure 7] FIG. 6 is a schematic diagram showing the configuration of a joint device according to a second embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing the configuration of a joint device of Example 3 according to Embodiment 2. [Figure 9] FIG. 10 is a cross-sectional view showing the configuration of a joint device of Example 4 according to Embodiment 2. [Figure 10] 1 is a perspective view of a robot device in which the joint device according to the embodiment is used in a joint portion. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a joint device according to an embodiment of the present invention will be described with reference to the drawings. In the drawings referred to in the following description of the embodiment and examples, members having the same functions will be designated by the same reference numerals unless otherwise specified.

[0016] [Embodiment 1] Fig. 1 is a schematic diagram showing the configuration of a joint device according to a first embodiment of the present invention. In Fig. 1, 1 is a fixed member, 2 is a reducer, 3 is a support member, 4 is an elastic body, 5 is an output member, and 13 is a motor. For example, in a robot device or the like, when the joint device of this embodiment is used as a joint that connects links, one link is attached to the fixed member 1 and the other link is attached to the output member 5. A chassis of a motor 13 and a chassis of a reducer 2 are fixed to a fixed member 1. The output shaft of the motor 13 is connected to the input shaft of the reducer 2, and the output shaft of the reducer 2 is connected to a support member 3. The support member 3 is connected to an output member 5 via an elastic body 4.

[0017] When the motor is driven to rotate its output shaft (R1), the output shaft of the reducer 2 rotates (R2) according to the reduction ratio, and the rotational force is transmitted to the support member 3 (R1>R2). The rotational force transmitted to the support member 3 is transmitted to the output member 5 via the elastic body 4, causing the output member 5 to rotate. At that time, because the elastic body 4 is an elastic body having torsional rigidity (K), it deforms according to the torque transmitted to the output member. In other words, a difference occurs between the rotational angle of the support member 3 relative to the fixed member 1 and the rotational angle of the output member 5 relative to the fixed member 1 according to the deformation of the elastic body 4.

[0018] In this embodiment, the fixed member 1 is provided with a rotation angle measuring sensor 8a at a position facing the support member 3, and a rotation angle measuring sensor 8b at a position facing the output member 5. In addition, the support member 3 is provided with a rotation angle measuring scale 7a at a position facing the rotation angle measuring sensor 8a, and the output member 5 is provided with a rotation angle measuring scale 7b at a position facing the rotation angle measuring sensor 8b. That is, a rotation angle measuring sensor 8a and a rotation angle measuring scale 7a are provided to measure the rotation angle of the output shaft of the reducer relative to the fixed member, and a rotation angle measuring sensor 8b and a rotation angle measuring scale 7b are provided to measure the rotation angle of the output member relative to the fixed member. The rotation angle can be measured by observing the opposing scales using these sensors.

[0019] In this embodiment, when the motor is driven to rotate its output shaft, the rotation angle E1 of the output shaft of the reducer relative to the fixed member, i.e., the rotation angle E1 of the support member 3 relative to the fixed member, is measured using the rotation angle measuring sensor 8a and the rotation angle measuring scale 7a. In addition, the rotation angle E2 of the output member relative to the fixed member is measured using the rotation angle measuring sensor 8b and the rotation angle measuring scale 7b. Then, if the torsional rigidity of the elastic portion is K, the torque T transmitted to the output member 5 is found using the relationship T = K × (E1 - E2). This calculation may be performed by a calculation unit included in the joint device, or by a control unit of a robot or the like in which the joint device is implemented. Alternatively, the calculation results of torque T for combinations of measured values ​​of rotation angles E1 and E2 may be stored in advance as a table in a storage device, and torque T may be read from the table each time a measurement is made.

[0020] 1, rotation angle measuring sensor 8a and rotation angle measuring sensor 8b are provided on fixed member 1, rotation angle measuring scale 7a is provided on support member 3, and rotation angle measuring scale 7b is provided on output member 5. Since rotation angle measuring sensor 8a and rotation angle measuring sensor 8b are both mounted on fixed member 1, it is also possible to mount both sensors on a single electric circuit board.

[0021] Furthermore, the first embodiment is not limited to the example shown in Fig. 1. That is, the rotation angle measuring scale 7a and the rotation angle measuring scale 7b may be provided on the fixed member 1, the rotation angle measuring sensor 8a may be provided on the support member 3, and the rotation angle measuring sensor 8b may be provided on the output member 5. In this case, since both the rotation angle measuring scale 7a and the rotation angle measuring scale 7b are mounted on the fixed member 1, it is also possible to mount both scales integrally.

[0022] The joint device of this embodiment can measure with high accuracy the rotation angle E1 of the output shaft of the reducer relative to the fixed member, the rotation angle E2 of the output member relative to the fixed member, and the torque T transmitted to the output member, and is compact.

[0023] Next, an embodiment of a robot device in which the joint device of this embodiment is used in a joint portion that connects links will be described. As an example, a six-axis articulated robot device 100 is shown in Fig. 10. The joint device of this embodiment is attached to six rotary joints J1 to J6 that connect links 200 to 206 in series, and while torque is transmitted between each link, the rotation angle of each joint and the torque transmitted via each joint are measured.

[0024] A tool, such as a robot hand 210, is attached to the link 206 at the tip according to the task. When an external force F is applied to the robot hand 210, the torque applied to each of the rotary joints J1 to J6 changes, which is read by a torque sensor in the joint device, and the control device 101 controls the rotary joints J1 to J6. This control is called force control, and by controlling the robot to move in the direction of the detected force, for example, flexibility in movement can be achieved. This function is highly useful in robots that control their movement according to the external force applied to the hand, such as assembly robots. A teaching pendant 102 is connected to the control device 101, and an operator instructs the robot to move.

[0025] The control device 101 of a robot equipped with the joint device of this embodiment can measure the rotation angle and drive current of the motor for each of the rotary joints J1 to J6, as well as the angle on the output side of the reducer and the torque transmitted to the output shaft, and feed this back to the motor. This control can improve the accuracy of the positioning control and force control of the robot. Of course, the robot equipped with the joint device of this embodiment is not limited to the configuration shown in FIG. 10, and the number of axes is not limited to six.

[0026] [Embodiment 2] 7 is a schematic diagram showing the configuration of a joint device according to a second embodiment of the present invention. In FIG. 7, 1 is a fixed member, 2 is a reducer, 3 is a support member, 4 is an elastic body, 5 is an output member, and 13 is a motor. For example, in a robot device or the like, when the joint device of this embodiment is used as a joint that connects links, one link is attached to the fixed member 1 and the other link is attached to the output member 5. A chassis of a motor 13 and one end of an elastic body 4 are fixed to the fixed member 1. The output shaft of the motor 13 is connected to the input shaft of a reducer 2, and the output shaft of the reducer 2 is connected to an output member 5. The chassis of the reducer 2 is fixed to a support member 3, and the support member 3 is connected to the fixed member 1 via the elastic body 4.

[0027] When the motor is driven to rotate its output shaft (R1), the rotational force is transmitted to the input shaft of the reducer 2, the output shaft of the reducer 2 rotates (R2) according to the reduction ratio, and the rotational force is transmitted to the output member 5 (R1>R2). When torque is transmitted to the output member 5 via the reducer 2, the elastic body 4 has torsional rigidity (K), and therefore, the elastic body 4 deforms according to the transmitted torque due to the reaction force received by the chassis of the reducer 2. In other words, a difference occurs between the rotation angle of the output member 5 relative to the fixed member 1 and the rotation angle of the output member 5 relative to the support member 3 according to the deformation of the elastic body 4.

[0028] In this embodiment, the fixed member 1 is provided with a rotation angle measuring sensor 8b at a position facing the output member 5. Furthermore, the support member 3 is provided with a rotation angle measuring sensor 8a at a position facing the output member 5. The output member 5 is provided with a rotation angle measuring scale 7a at a position facing the rotation angle measuring sensor 8a, and a rotation angle measuring scale 7b at a position facing the rotation angle measuring sensor 8b. That is, a rotation angle measuring sensor 8b and a rotation angle measuring scale 7b are installed to measure the rotation angle of the output member relative to the fixed member, and a rotation angle measuring sensor 8a and a rotation angle measuring scale 7a are installed to measure the rotation angle of the output member relative to the support member. The rotation angle can be measured by observing the opposing scales using these sensors.

[0029] In this embodiment, when the motor is driven to rotate its output shaft, the rotation angle E3 of the output shaft of the reducer relative to the support member 3, i.e., the rotation angle E3 of the output member 5 relative to the support member 3, is measured using the rotation angle measuring sensor 8a and the rotation angle measuring scale 7a. In addition, the rotation angle E4 of the output member 5 relative to the fixed member 1 is measured using the rotation angle measuring sensor 8b and the rotation angle measuring scale 7b. The torque T transmitted to the output member 5 is calculated using the relationship T = K × (E3 - E4), where K is the torsional rigidity of the elastic section. This calculation may be performed by a calculation unit included in the joint device, or by a control unit of a robot or the like in which the joint device is implemented. Alternatively, the calculation results of torque T for combinations of measured values ​​of rotation angles E3 and E4 may be stored in advance as a table in a storage device, and torque T may be read from the table each time a measurement is made.

[0030] 7, rotation angle measuring scale 7a and rotation angle measuring scale 7b are provided on output member 5, rotation angle measuring sensor 8a is provided on support member 3, and rotation angle measuring sensor 8b is provided on fixed member 1. Since rotation angle measuring scale 7a and rotation angle measuring scale 7b are both mounted on output member 5, it is also possible to mount both scales integrally.

[0031] Furthermore, the second embodiment is not limited to the example shown in Fig. 7. That is, the rotation angle measuring sensors 8a and 8b may be provided on the output member 5, the rotation angle measuring scale 7a on the support member 3, and the rotation angle measuring scale 7b on the fixed member 1. In this case, since the rotation angle measuring sensors 8a and 8b are both mounted on the output member 5, it is also possible to mount the sensors on a single electric circuit board.

[0032] The joint device of this embodiment can measure with high accuracy the rotation angle E3 of the output shaft of the reducer relative to the support member 3, the rotation angle E4 of the output member 5 relative to the fixed member 1, and the torque transmitted to the output member, and is compact. The joint device of this embodiment, like the first embodiment, can be used in joints that connect links of various robots. [Example]

[0033] [Example 1] Example 1 will be described as a specific example of the first embodiment. 2 is a cross-sectional view showing the configuration of the joint device of Example 1. Note that wiring, piping, and the like associated with the joint device are omitted from the illustration.

[0034] (fixing member) A motor 13 is fixed to the fixed member 1, which is a rigid body, with bolts (not shown). A speed reducer fixed shaft 18 (circular spline) is also fixed to the fixed member 1. A cross roller bearing 20 of the speed reducer is also fixed to the fixed member 1, and a rotating shaft 19 (output shaft of the speed reducer) is rotatably held via the cross roller bearing 20. A substrate 9 on which rotation angle measurement sensors 8a and 8b are mounted is fixed to the fixed member 1. When the articulated device is used as a joint for connecting links of a robot arm, for example, the fixed member 1 is fixed to one of the links.

[0035] (Reducer) The reducer used in this embodiment is called a wave gear reducer, and is composed of three main parts: a reducer input shaft 16 (wave generator), a reducer output shaft 17 (flexspline), and a reducer fixed shaft 18 (circular spline). The reducer input shaft 16 is an elliptical cam with a rolling bearing. The reducer output shaft 17 is an external gear with a cup shape that undergoes elliptical deformation. The reducer fixed shaft 18 is an internal gear with a different number of teeth from the reducer output shaft. The reducer input shaft 16 pushes the reducer output shaft 17 (flexspline) apart at two points on both ends of the major axis of the elliptical cam to mesh with the reducer fixed shaft 18 (circular spline). Because the numbers of teeth on both shafts are different, when the reducer input shaft rotates once, the reducer output shaft rotates by the difference in the number of teeth relative to the reducer fixed shaft.

[0036] The output shaft 15 of the motor is connected to the input shaft 16 of the reducer, the fixed shaft 18 of the reducer is fixed to the fixed member 1, and the output shaft 17 of the reducer is fixed to the rotating shaft 19. With this configuration, when the output shaft 15 of the motor 13 rotates, the input shaft 16 of the reducer rotates, and the rotating shaft 19, which is the output shaft of the reducer, rotates at a reduced rotational speed relative to the fixed member 1.

[0037] (torque and angle measurement system) The rotating shaft 19, which is the output shaft of the reducer, is connected to a support member 3. The support member 3 is connected to one end of an elastic body 4, and the other end of the elastic body 4 is connected to an output member 5. Therefore, when the output shaft of the reducer rotates according to the reduction ratio and a rotational force is transmitted to the support member 3, the rotational force is transmitted to the output member 5 via the elastic body 4, causing the output member 5 to rotate. When the joint device is used as a joint that connects the links of a robot arm, for example, the output member 5 is fixed to the link opposite to the link to which the fixed member 1 is connected. In the example of FIG. 2, the output member 5 is fixed to a link 32 via a boss portion 31.

[0038] When the output shaft of the reducer rotates, the elastic body 4 has torsional rigidity (K) and therefore deforms in accordance with the torque transmitted to the output member 5. In other words, a difference occurs between the rotation angle of the support member 3 relative to the fixed member 1 and the rotation angle of the output member 5 relative to the fixed member 1 in accordance with the deformation of the elastic body 4.

[0039] A rotation angle measuring scale 7a is provided on the surface of the support member 3 on the side facing the fixed member 1, and a rotation angle measuring scale 7b is provided on the surface of the output member 5 on the side facing the fixed member 1. A rotation angle measuring sensor 8a provided on the fixed member 1 measures the rotation angle measuring scale 7a arranged on the support member 3 to measure the rotation angle of the support member 3 relative to the fixed member 1. Furthermore, a rotation angle measuring sensor 8b provided on the fixed member 1 measures the rotation angle measuring scale 7b arranged on the output member 5 to measure the rotation angle of the output member 5 relative to the fixed member 1. Optical sensors are preferably used for these sensors, and displacement can be measured by capturing an image of the scale. It should be noted that instead of such an optical encoder, a magnetic encoder can also be used.

[0040] Next, with reference to FIG. 3, the configuration of the elastic body 4 will be described in more detail. In FIG. 2, the support member 3 connected to the output shaft of the reducer includes a portion shown as an inner ring 29 in FIG. 3. In addition, in FIG. 2, the output member 5 fixed to the link 32 via a boss portion 31 includes a portion shown as an outer ring 28 in FIG. 3. The inner ring 29 and the outer ring 28 are both concentric annular members centered on the rotation axis of the joint. In addition, the elastic body 4 connecting the support member 3 and the output member 5 in FIG. 2 is made up of a number of leaf springs 30, which are plate-shaped elastic bodies, arranged radially around the rotation axis of the joint as shown in FIG. 3. The leaf springs 30 are connected to the inner ring 29 and the outer ring 28 so that the main surface of each leaf spring 30 is perpendicular to the main surface of the inner ring 29 and the main surface of the outer ring 28. That is, the main surface of each leaf spring 30 is arranged parallel to the rotation axis of the joint. However, leaf springs have the characteristic that their bending rigidity in a direction intersecting the main surface is lower than their bending rigidity in a direction parallel to the main surface. Therefore, by arranging the leaf springs 30 radially as shown in Figure 3, the overall rigidity is soft only in the rotational direction θ around the Z axis in the coordinate system shown in the figure, and stiff in the rotational directions around the X and Y axes. By increasing the rigidity other than the rotational direction θ where torque is detected, deformation in the rotational directions around the X and Y axes when torque in the rotational direction θ is applied is reduced. This ensures a suitable rigidity ratio for an elastic body used in a torque sensor, thereby reducing measurement error. Furthermore, the simple configuration of radially arranging leaf springs allows for easy manufacturing and a relatively small size. In other words, a joint device capable of detecting torque and position with high accuracy and that can be miniaturized is realized.

[0041] Next, the configuration of the rotation angle measuring sensor and scale will be described in more detail with reference to FIG. Rotation angle measuring sensor 8a provided on fixed member 1 measures rotation angle measuring scale 7a arranged on support member 3 to measure the rotation angle of support member 3 relative to fixed member 1. Rotation angle measuring sensor 8b provided on fixed member 1 measures rotation angle measuring scale 7b arranged on output member 5 to measure the rotation angle of output member 5 relative to fixed member 1.

[0042] 4, a rotation angle measuring scale 7b, and rotation angle measuring sensors 8b-1 and 8b-2 that measure it are provided as a first angle detector for measuring the rotation angle of the output member 5 relative to the fixed member 1. Furthermore, a rotation angle measuring scale 7a, and rotation angle measuring sensors 8a-1 and 8a-2 that measure it are provided as a second angle detector for measuring the rotation angle of the support member 3 relative to the fixed member 1.

[0043] The substrate 9 on which the four rotation angle measurement sensors are mounted is an electric circuit board fixed to the fixed member 1. In addition to the four rotation angle measurement sensors, a signal generation circuit for driving the sensors, a circuit for processing the sensor output signals, wiring, and connectors are also mounted as appropriate on the substrate 9. In this embodiment, the rotation angle measurement sensors of the first angle detector and the second angle detector can be mounted on one side of the same substrate 9, thereby simultaneously achieving miniaturization and cost reduction.

[0044] The rotation angle measuring sensors 8b-1 and 8b-2 constituting the first angle detector are fixed on the same surface of the substrate 9 and are arranged opposite each other at two locations 180 degrees apart on a large diameter circle centered on the rotation axis of the joint. In addition, the rotation angle measurement sensors 8a-1 and 8a-2 that constitute the second angle detector are fixed on the same surface of the substrate 9 and are arranged opposite each other at two locations 180 degrees apart on a small diameter circle centered on the rotation axis of the joint. The first angle detector and the second angle detector are arranged with a 90 degree offset in the θ direction, but this is not necessarily limited to 90 degrees, and any suitable arrangement can be adopted for implementation.

[0045] In this embodiment, the two rotation angle measurement sensors that make up the angle detector are arranged facing each other at two locations 180 degrees apart on the same circumference in order to make it possible to cancel eccentricity error through calculation. Eccentricity error is the deviation between the center of the rotation axis and the center of angle measurement. If there is eccentricity error, the position of the sensor will change as the joint rotates, resulting in measurement error.

[0046] The direction of this eccentricity error is φ and its magnitude is δ. Furthermore, if the radius of rotation of the sensor is R and the rotation angle of the joint is θ, the detected values ​​S0 and S1 from the two sensors are 180 are expressed as the following equations, respectively. The second term in each equation is the eccentricity error.

[0047]

number

[0048]

number

[0049] By modifying these equations, the influence of the eccentricity error can be eliminated as shown in the following equation.

number

[0050] In other words, by arranging the two sensors opposite each other so that their phases differ by 180 degrees and performing calculations based on the detected values, it is possible to measure angles without being affected by eccentricity errors.

[0051] In the above configuration, torque T is calculated from the following equation using rotation angle E1 measured by rotation angle measuring sensor 8b of the first angle detector provided on substrate 9 and rotation angle E2 measured by rotation angle measuring sensor 8a of the second angle detector, where K is the torsional rigidity coefficient of the elastic body.

[0052]

number

[0053] As described above, the joint device of this embodiment can measure with high accuracy the rotation angle E1 of the output shaft of the reducer relative to the fixed member, the rotation angle E2 of the output member relative to the fixed member, and the torque transmitted to the output member, while being compact. Furthermore, since angle detection and torque detection can be performed using the same encoder, costs can be reduced. Furthermore, the encoder sensor can be mounted on one side of the circuit board, which reduces dimensions. Furthermore, since the rotation angle measurement sensor and its associated electrical circuitry can be integrated onto a single circuit board, costs can be reduced.

[0054] [Example 2] With respect to the first embodiment, an example 2 will be shown which is different from the example 1. Explanation of the parts common to the example 1 will be omitted. 5 is a cross-sectional view showing the configuration of the joint device of Example 2. Note that wiring, piping, etc. associated with the joint device are omitted from the illustration.

[0055] In Example 1, rotation angle measuring sensors 8a and 8b were mounted on fixed member 1, rotation angle measuring scale 7a was provided on the surface of support member 3, and rotation angle measuring scale 7b was provided on the surface of output member 5.

[0056] In contrast to this, in Example 2, a rotation angle measuring scale 7 shared by the first angle detector and the second angle detector is provided on the fixed member 1, a rotation angle measuring sensor 8b is disposed on the support member 3, and a rotation angle measuring sensor 8a is disposed on the output member 5. The rotation angle measuring sensor 8a of the first angle detector for measuring the rotation angle of the output member 5 relative to the fixed member 1 is mounted on a substrate 9a. Furthermore, the rotation angle measuring sensor 8b of the second angle detector for measuring the rotation angle of the support member 3 relative to the fixed member 1 is mounted on a substrate 9b.

[0057] Next, the configuration of the rotation angle measuring sensor and scale will be described in more detail with reference to FIG. Rotation angle measuring sensor 8b fixed to support member 3 measures rotation angle measuring scale 7 fixed to fixed member 1 to measure the rotation angle of support member 3 relative to fixed member 1. Rotation angle measuring sensor 8a provided on output member 5 measures rotation angle measuring scale 7 arranged on fixed member 1 to measure the rotation angle of output member 5 relative to fixed member 1.

[0058] 6, a rotation angle measuring scale 7, and rotation angle measuring sensors 8a-1 and 8a-2 that measure it are provided as a first angle detector for measuring the rotation angle of the output member 5 relative to the fixed member 1. Furthermore, a rotation angle measuring scale 7, and rotation angle measuring sensors 8b-1 and 8b-2 that measure it are provided as a second angle detector for measuring the rotation angle of the support member 3 relative to the fixed member 1. Rotation angle measuring sensors 8a-1 and 8a-2 are mounted on substrate 9a, and rotation angle measuring sensors 8b-1 and 8b-2 are mounted on substrate 9b. In addition to the two rotation angle measuring sensors, each of substrates 9a and 9b is also appropriately equipped with a signal generating circuit for driving the sensors, a circuit for processing the sensor output signals, wiring, and connectors.

[0059] Rotation angle measuring sensors 8a-1 and 8a-2 that constitute the first angle detector are fixed on the same surface of substrate 9a and are arranged at two locations 180 degrees apart on a circumference of a predetermined radius centered on the rotation axis of the joint. Rotation angle measuring sensors 8b-1 and 8b-2 that constitute the second angle detector are fixed on the same surface of substrate 9b and are arranged at two locations 180 degrees apart on a circumference of the same predetermined radius as the first angle detector.

[0060] Because the rotation angle sensors of the first angle detector and the second angle detector are arranged on the same circumference, it is possible to share the rotation angle measurement scale 7, and only one scale is required. That is, in this embodiment, the rotation angle measurement scales of the first angle detector and the second angle detector can be mounted on one side of the fixing member 1 as a single scale, thereby achieving both miniaturization and cost reduction. In FIG. 6, the first angle detector and the second angle detector are arranged with a 90 degree offset in the θ direction, but this does not necessarily have to be limited to 90 degrees, and any suitable arrangement can be adopted for implementation.

[0061] As with the first embodiment, the joint device of this embodiment can measure with high accuracy the rotation angle E1 of the output shaft of the reducer relative to the fixed member, the rotation angle E2 of the output member relative to the fixed member, and the torque transmitted to the output member. Furthermore, since the same encoder can be used to detect the angle and torque, costs can be reduced. Furthermore, the encoder scale can be mounted on one side of the fixed member 1, reducing the size and cost.

[0062] [Example 3] Example 3 will be shown as a specific example of Embodiment 2. Fig. 8 is a cross-sectional view showing the configuration of the joint device of Example 3. Note that wiring, piping, etc. associated with the joint device are omitted from the illustration.

[0063] In Example 1 and Example 2 according to Embodiment 1, the elastic body is provided between the output member and a support member fixed to the output shaft of the reducer. In contrast, in Example 3 according to Embodiment 2, the elastic body is provided between the fixed member and a support member to which the chassis of the reducer is fixed.

[0064] In contrast to this, in this example according to embodiment 2, a rotation angle measuring scale 7b and a rotation angle measuring sensor 8b that measures this are provided as a first angle detector for measuring the rotation angle of the output member 5 relative to the fixed member 1. Furthermore, a rotation angle measuring scale 7a and a rotation angle measuring sensor 8a that measures this are provided as a second angle detector for measuring the rotation angle of the output member 5 relative to the support member 3.

[0065] (fixing member) A motor 13 is fixed to a rigid fixed member 1 with bolts (not shown). One end of each of a plurality of plate-like elastic bodies 4 arranged radially around the rotation axis is connected to the fixed member 1. A rotation angle measurement scale 7b of the first angle detector is also fixed to the fixed member 1. When the articulated device is used as a joint for connecting links of a robot arm, for example, the fixed member 1 is fixed to one of the links.

[0066] (Reducer) The reducer used in this embodiment is called a wave gear reducer, and is composed of three main parts: a reducer input shaft 16 (wave generator), a reducer output shaft 17 (flexspline), and a reducer fixed shaft 18 (circular spline). The reducer input shaft 16 is an elliptical cam with a rolling bearing. The reducer output shaft 17 is an external gear with a cup shape that undergoes elliptical deformation. The reducer fixed shaft 18 is an internal gear with a different number of teeth from the reducer output shaft. The reducer input shaft 16 pushes the reducer output shaft 17 (flexspline) apart at two points on both ends of the major axis of the elliptical cam to mesh with the reducer fixed shaft 18 (circular spline). Because the numbers of teeth on both shafts are different, when the reducer input shaft rotates once, the reducer output shaft rotates by the difference in the number of teeth relative to the reducer fixed shaft.

[0067] The output shaft 15 of the motor is connected to the input shaft 16 of the reducer, the fixed shaft 18 of the reducer and the cross roller bearing 20 are fixed to the support member 3, and the output shaft 17 of the reducer is fixed to the rotating shaft 19. With this configuration, when the output shaft 15 of the motor 13 rotates, the input shaft 16 of the reducer rotates, and the rotating shaft 19, which is the output shaft of the reducer, rotates at a reduced rotational speed relative to the fixed member 1. The rotating shaft 19, which is the output shaft of the reducer, is connected to the output member 5. When the joint device is used, for example, as a joint that connects the links of a robot arm, the output member 5 is fixed to the link on the opposite side to the link to which the fixed member 1 is connected.

[0068] (torque and angle measurement system) One end of each of a plurality of plate-shaped elastic bodies 4 arranged radially around the rotation axis is connected to the support member 3. In other words, the support member 3 is connected to the fixed member 1 via the plurality of plate-shaped elastic bodies 4. Therefore, when the output shaft of the reducer rotates in accordance with the reduction ratio and a rotational force is transmitted to the output member 5, a reaction to the rotational force acts on the elastic body 4. At that time, because the elastic body 4 has torsional rigidity (K), it deforms in accordance with the torque transmitted to the output member 5. In other words, a difference occurs between the rotation angle of the output member 5 relative to the fixed member 1 and the rotation angle of the output member 5 relative to the support member 3 in accordance with the deformation of the elastic body 4.

[0069] A rotation angle measuring scale 7a is provided on the surface of the support member 3 on the side facing the output member 5, and a rotation angle measuring scale 7b is provided on the surface of the fixed member 1 on the side facing the output member 5. A rotation angle measuring sensor 8a provided on the output member 5 measures the rotation angle measuring scale 7a arranged on the support member 3 to measure the rotation angle of the output member 5 relative to the support member 3. Furthermore, a rotation angle measuring sensor 8b provided on the output member 5 measures the rotation angle measuring scale 7b arranged on the fixed member 1 to measure the rotation angle of the output member 5 relative to the fixed member 1. Optical sensors are preferably used for these sensors, and displacement can be measured by capturing an image of the scale. It should be noted that instead of such an optical encoder, a magnetic encoder can also be used.

[0070] Next, the configuration of the output side will be described in more detail with reference to FIG. 3. The support member 3 connected to the reducer fixed shaft 18 in FIG. 8 includes a portion shown as an inner ring 29 in FIG. 3. The fixed member 1 shown in FIG. 8 includes a portion shown as an outer ring 28 in FIG. 3. The inner ring 29 and the outer ring 28 are both concentric annular members centered on the rotation axis of the joint. The elastic body 4 connecting the support member 3 and the fixed member 1 in FIG. 8 is composed of a number of leaf springs 30, which are plate-shaped elastic bodies, arranged radially around the rotation axis of the joint as shown in FIG. 3. The leaf springs 30 are connected to the inner ring 29 and the outer ring 28 so that the main surface of each leaf spring 30 is perpendicular to the main surface of the inner ring 29 and the main surface of the outer ring 28. That is, the main surface of each leaf spring 30 is arranged parallel to the rotation axis of the joint, but the leaf springs have the characteristic that their bending rigidity in a direction intersecting their main surfaces is lower than their bending rigidity in a direction parallel to their main surfaces. Therefore, by arranging the leaf springs 30 radially as shown in Figure 3, the overall rigidity is soft only in the rotational direction θ around the Z axis in the coordinate system shown in the figure, and stiff in the rotational directions around the X and Y axes. By increasing the rigidity other than the rotational direction θ where torque is detected, deformation in the rotational directions around the X and Y axes is reduced when torque in the rotational direction θ is applied. This ensures an optimal rigidity ratio for an elastic body for a torque sensor, thereby reducing measurement errors. Furthermore, the simple configuration of arranging leaf springs radially allows for easy manufacturing and a relatively small size. In other words, a joint device is realized that can detect torque and position with high accuracy and can be miniaturized.

[0071] Next, the configuration of the rotation angle measuring sensor and scale will be described in more detail with reference to FIG. A rotation angle measuring sensor 8a provided on the output member 5 measures a rotation angle measuring scale 7a arranged on the support member 3 to measure the rotation angle of the output member 5 relative to the support member 3. In addition, a rotation angle measuring sensor 8b provided on the output member 5 measures a rotation angle measuring scale 7b arranged on the fixed member 1 to measure the rotation angle of the output member 5 relative to the fixed member 1.

[0072] 4, a rotation angle measuring scale 7b, and rotation angle measuring sensors 8b-1 and 8b-2 that measure this are provided as a first angle detector for measuring the rotation angle of the output member 5 relative to the fixed member 1. Furthermore, a rotation angle measuring scale 7a, and rotation angle measuring sensors 8a-1 and 8a-2 that measure this are provided as a second angle detector for measuring the rotation angle of the output member 5 relative to the support member 3.

[0073] The substrate 9 on which the four rotation angle measurement sensors are mounted is an electric circuit board fixed to the output member 5. In addition to the four rotation angle measurement sensors, a signal generation circuit for driving the sensors, a circuit for processing the sensor output signals, wiring, and connectors are also mounted as appropriate on the substrate 9. In this embodiment, the rotation angle measurement sensors of the first angle detector and the second angle detector can be mounted on one side of the same substrate 9, thereby achieving both miniaturization and cost reduction.

[0074] The rotation angle measuring sensors 8b-1 and 8b-2 that constitute the first angle detector are fixed on the same surface of the substrate 9 and are arranged at two locations 180 degrees apart on a large diameter circle centered on the rotation axis of the joint. In addition, the rotation angle measurement sensors 8a-1 and 8a-2 that constitute the second angle detector are fixed on the same surface of the substrate 9 and are arranged at two locations 180 degrees apart on a small diameter circle centered on the rotation axis of the joint. The first angle detector and the second angle detector are arranged with a 90 degree offset in the θ direction, but this is not necessarily limited to 90 degrees, and any suitable arrangement can be adopted for implementation.

[0075] In this embodiment, the two rotation angle measuring sensors that make up the angle detector are arranged at two locations 180 degrees apart on the same circumference in order to enable eccentricity error to be cancelled out by calculation. As explained in the first embodiment using equations 1 to 3, by arranging the two sensors opposite each other so that their phases are 180 degrees apart and performing calculations based on the detected values, angle measurement that is not affected by eccentricity error is possible.

[0076] In this embodiment, when the motor is driven to rotate its output shaft, the rotation angle E3 of the output shaft of the reducer relative to the support member 3, i.e., the rotation angle E3 of the output member 5 relative to the support member 3, is measured using the rotation angle measuring sensor 8a and the rotation angle measuring scale 7a. In addition, the rotation angle E4 of the output member 5 relative to the fixed member 1 is measured using the rotation angle measuring sensor 8b and the rotation angle measuring scale 7b. Then, when the torsional rigidity of the elastic portion is K, the torque T transmitted to the output member 5 is calculated using the relationship T = K × (E3 - E4). This calculation may be performed by a calculation unit included in the joint device, or may be performed by a control unit of a robot or the like in which the joint device is implemented.

[0077] As described above, the joint device of this embodiment can measure the rotation angle E3 of the output member 5 relative to the support member 3, the rotation angle E4 of the output member 5 relative to the fixed member 1, and the torque transmitted to the output member with high accuracy, and is compact. In addition, since the same encoder can be used to detect angle and torque, costs can be reduced. Furthermore, the encoder sensor can be mounted on one side of a circuit board, which reduces dimensions. In addition, since the rotation angle measurement sensor and its associated electrical circuit can be integrated onto a single circuit board, costs can be reduced.

[0078] [Example 4] With respect to embodiment 2, example 4 will be described, which is different from example 3. Explanation of parts common to example 3 will be omitted. 9 is a cross-sectional view showing the configuration of the joint device of Example 4. Note that wiring, piping, etc. associated with the joint device are omitted from the illustration.

[0079] In Example 3, rotation angle measuring sensors 8a and 8b were mounted on the output member 5, rotation angle measuring scale 7a was provided on the surface of the support member 3, and rotation angle measuring scale 7b was provided on the surface of the fixed member 1.

[0080] In contrast to this, in Example 4, a rotation angle measuring scale 7 shared by the first angle detector and the second angle detector is provided on the output member 5, a rotation angle measuring sensor 8b is disposed on the support member 3, and a rotation angle measuring sensor 8a is disposed on the fixed member 1. The rotation angle measuring sensor 8a of the first angle detector for measuring the rotation angle of the output member 5 relative to the fixed member 1 is mounted on a substrate 9a. Furthermore, the rotation angle measuring sensor 8b of the second angle detector for measuring the rotation angle of the output member 5 relative to the support member 3 is mounted on a substrate 9b.

[0081] Next, the configuration of the rotation angle measuring sensor and scale will be described in more detail with reference to FIG. The rotation angle measuring sensor 8b provided on the support member 3 measures the rotation angle measuring scale 7 arranged on the output member 5 to measure the rotation angle of the output member 5 relative to the support member 3. The rotation angle measuring sensor 8a provided on the fixed member 1 measures the rotation angle measuring scale 7 arranged on the output member 5 to measure the rotation angle of the output member 5 relative to the fixed member 1.

[0082] 6, a rotation angle measuring scale 7, and rotation angle measuring sensors 8a-1 and 8a-2 that measure it are provided as a first angle detector for measuring the rotation angle of the output member 5 relative to the fixed member 1. Furthermore, a rotation angle measuring scale 7, and rotation angle measuring sensors 8b-1 and 8b-2 that measure it are provided as a second angle detector for measuring the rotation angle of the output member 5 relative to the support member 3. Rotation angle measuring sensors 8a-1 and 8a-2 are mounted on substrate 9a, and rotation angle measuring sensors 8b-1 and 8b-2 are mounted on substrate 9b. In addition to the two rotation angle measuring sensors, each of substrates 9a and 9b is also appropriately equipped with a signal generating circuit for driving the rotation angle measuring sensors, a circuit for processing the sensor output signals, wiring, and connectors.

[0083] Rotation angle measuring sensors 8a-1 and 8a-2 that constitute the first angle detector are fixed on the same surface of substrate 9a and are arranged at two locations 180 degrees apart on a circumference of a predetermined radius centered on the rotation axis of the joint. Rotation angle measuring sensors 8b-1 and 8b-2 that constitute the second angle detector are fixed on the same surface of substrate 9b and are arranged at two locations 180 degrees apart on a circumference of the same predetermined radius as the first angle detector.

[0084] Because the rotation angle sensors of the first angle detector and the second angle detector are arranged on the same circumference, it is possible to share the rotation angle measurement scale 7, and only one scale is required. That is, in this embodiment, the rotation angle measurement scales of the first angle detector and the second angle detector can be made into a single scale and mounted on one side of the output member 5, thereby achieving both miniaturization and cost reduction. In FIG. 6, the first angle detector and the second angle detector are arranged with a 90 degree offset in the θ direction, but this does not necessarily have to be limited to 90 degrees, and any suitable arrangement can be adopted for implementation.

[0085] Similar to the third embodiment, the joint device of this embodiment can measure with high accuracy the rotation angle E3 of the output member 5 relative to the support member 3, the rotation angle E4 of the output member 5 relative to the fixed member 1, and the torque T transmitted to the output member, while being compact. Furthermore, since the same encoder can be used to detect the angle and torque, costs can be reduced. Furthermore, the encoder scale can be mounted on one side of the output member 5, which reduces the size and costs.

[0086] [Other embodiments] The present invention is not limited to the above-described embodiments and examples, and many modifications are possible within the technical concept of the present invention. The joint device embodying the present invention is capable of detecting torque and rotation angle with high accuracy, and has excellent control accuracy of the rotation angle. If the joint device of this embodiment is attached to a robot device as a detection device, the work accuracy of the robot device can be improved. That is, for example, if a joint device embodying the present invention is attached to each joint of the articulated robot shown in FIG. 10, and the robot is placed on a manufacturing line that assembles and processes articles, and an article manufacturing process is performed, a high-precision article manufacturing method can be realized. Of course, the present invention can be implemented in articulated robots that perform various tasks with high accuracy, not limited to article manufacturing.

[0087] Furthermore, when an external force is applied to a robot or other device, the device may be used as a detection device for detecting with high precision the torque of the external force or the magnitude of the rotation angle caused by the external force. [Explanation of symbols]

[0088] 1···Fixing member / 2···Reduction gear / 3···Support member / 4···Elastic body / 5···Output member / 7, 7a, 7b···Scale for measuring rotation angle / 8a, 8a-1, 8a-2, 8b, 8b-1, 8b-2···Sensor for measuring rotation angle / 9, 9a, 9b···Platform / 13···Motor / 15···Motor output shaft / 16···Reduction gear input shaft / 17···Reduction gear output shaft / 18···Reduction gear Speed ​​changer fixed shaft / 19···Rotating shaft / 20···Cross roller bearing / 28···Outer ring / 29···Inner ring / 30···Leaf spring / 31···Boss section / 32···Link / 100···6-axis articulated robot device / 101···Control device / 102···Teaching pendant / 200~206···Link / 210···Robot hand / J1~J6···Rotary joint

Claims

1. a motor provided on the fixed member; a support member driven by the motor to move relative to the fixed member; an output member connected to the support member by an elastic body and movable relative to the support member, a first scale is provided on one of the fixed member and the support member, and a first sensor is provided on the other of the fixed member and the support member; a second scale is provided on one of the fixed member and the output member, and a second sensor is provided on the other of the fixed member and the output member; a substrate is provided on the fixed member or the support member and the output member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; the first sensor and the second sensor are provided on a surface of the substrate facing the first scale and the second scale, obtaining a relative displacement between the fixed member and the support member using the first scale and the first sensor, and obtaining a relative displacement between the fixed member and the output member using the second scale and the second sensor; A drive device characterized by:

2. the elastic bodies are a plurality of plate-shaped elastic bodies arranged radially around the rotation axis of the output member, and are provided on the support member and the output member so that a main surface of each plate-shaped elastic body is perpendicular to a circumference around the rotation axis of the output member.

2. The drive device according to claim 1.

3. The bending rigidity of the elastic body in a direction intersecting the main surface is smaller than the bending rigidity of the elastic body in a direction parallel to the main surface.

3. The drive device according to claim 2.

4. a relative displacement between the fixed member and the support member obtained using the first scale and the first sensor; a relative displacement between the fixed member and the output member obtained using the second scale and the second sensor; and Based on the rigidity of the elastic body, obtaining information about the torque transmitted to the output member; 4. The drive device according to claim 1, wherein the drive device is a drive unit.

5. Two first sensors and two second sensors are provided, The two first sensors are arranged to be opposed to each other at approximately 180° intervals, and the two second sensors are arranged to be opposed to each other at approximately 180° intervals.

5. The drive device according to claim 1, wherein the drive device is a drive unit.

6. when the substrate is provided on the fixed member, the first scale is provided on the support member and the second scale is provided on the output member, the first sensor and the second sensor are provided on a surface of the substrate facing the first scale provided on the support member and the second scale provided on the output member, 6. The drive device according to claim 1, wherein the drive device is a drive unit.

7. the first sensor and the second sensor are provided on the same surface of the substrate facing the first scale and the second scale, 7. The drive device according to claim 6.

8. The substrate has a circular ring shape.

8. The drive device according to claim 1, wherein the drive device is a drive unit.

9. the first scale and the second scale are annular; 9. The drive device according to claim 1, wherein the drive device is a drive unit.

10. the first scale and the second scale are arranged so that their centers are coaxial.

10. The drive device according to claim 1.

11. When the substrate is provided on the support member and the output member, the first scale and the second scale are provided on the fixing member, and the substrate has a first substrate provided on the support member and a second substrate provided on the output member, the first sensor is provided on a surface of the first substrate facing the first scale provided on the fixed member, and the second sensor is provided on a surface of the second substrate facing the second scale provided on the fixed member; 6. The drive device according to claim 1, wherein the drive device is a drive unit.

12. the first scale and the second scale are a single scale; 12. The drive device according to claim 11.

13. a signal processing circuit for processing signals from the first sensor and the second sensor is provided on the substrate; 13. The drive device according to claim 1, wherein the drive device is a drive unit.

14. a reducer that reduces the speed of the motor; The reducer is provided on the fixed member.

14. The drive device according to claim 1, wherein the drive device is a drive unit.

15. the first sensor and the second sensor are optical or magnetic sensors; 15. The drive device according to claim 1, wherein the drive device is a drive unit.

16. a motor provided on the fixed member; a reducer that reduces the speed of the motor; an output member driven by the motor and the reducer and moving relative to the fixed member; a support member that is provided on the reducer and connected to the fixed member by an elastic body, and is movable relative to the fixed member, a first scale is provided on one of the fixed member and the output member, and a first sensor is provided on the other of the fixed member and the output member; a second scale is provided on one of the support member and the output member, and a second sensor is provided on the other of the support member and the output member; a substrate is provided on the output member or the fixed member and the support member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; obtaining a relative displacement between the fixed member and the output member using the first scale and the first sensor, and obtaining a relative displacement between the output member and the support member using the second scale and the second sensor; A drive device characterized by:

17. the first sensor and the second sensor are provided on a surface of the substrate facing the first scale and the second scale, 17. The drive device according to claim 16.

18. when the substrate is provided on the output member, the first scale is provided on the fixing member and the second scale is provided on the support member; the first sensor and the second sensor are provided on a surface of the substrate facing the first scale provided on the fixing member and the second scale provided on the support member, 18. The drive device according to claim 16 or 17.

19. the first sensor and the second sensor are provided on the same surface of the substrate facing the first scale and the second scale, 19. The drive device according to any one of claims 16 to 18.

20. When the substrate is provided on the fixed member and the support member, the first scale and the second scale are provided on the output member, and the substrate has a first substrate provided on the fixed member and a second substrate provided on the support member, the first sensor is provided on a surface of the first substrate facing the first scale provided on the output member, and the second sensor is provided on a surface of the second substrate facing the second scale provided on the output member; 17. The drive device according to claim 16.

21. the first scale and the second scale are a single scale; 21. The drive device according to claim 20.

22. A drive device according to any one of claims 1 to 21 and a link. A robot characterized by:

23. The robot according to claim 22 assembles or processes an article. A method for manufacturing an article.

24. a motor provided on the fixed member; a support member driven by the motor to move relative to the fixed member; an output member connected to the support member by an elastic body and movable relative to the support member; A control method for a drive device including a control unit, a first scale is provided on one of the fixed member and the support member, and a first sensor is provided on the other of the fixed member and the support member; a second scale is provided on one of the fixed member and the output member, and a second sensor is provided on the other of the fixed member and the output member; a substrate is provided on the fixed member or the support member and the output member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; the first sensor and the second sensor are provided on a surface of the substrate facing the first scale and the second scale, the control unit acquires a relative displacement between the fixed member and the support member using the first scale and the first sensor, acquires a relative displacement between the fixed member and the output member using the second scale and the second sensor, and controls the motor based on the acquired results. A control method comprising:

25. a motor provided on the fixed member; a reducer that reduces the speed of the motor; an output member driven by the motor and the reducer and moving relative to the fixed member; a support member provided in the reducer and connected to the fixed member by an elastic body, the support member being movable relative to the fixed member; A control method for a drive device including a control unit, a first scale is provided on one of the fixed member and the output member, and a first sensor is provided on the other of the fixed member and the output member; a second scale is provided on one of the support member and the output member, and a second sensor is provided on the other of the support member and the output member; a substrate is provided on the output member or the fixed member and the support member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; obtaining a relative displacement between the fixed member and the output member using the first scale and the first sensor, obtaining a relative displacement between the output member and the support member using the second scale and the second sensor, and controlling the motor based on the obtained results. A control method comprising:

26. A detection device for detecting information about torque in an output member that moves when driven by a motor and outputs torque, comprising: the detection device includes a fixed member on which the motor is provided, a support member driven by the motor and movable relative to the fixed member, an output member connected to the support member by an elastic body and movable relative to the support member, and a processing unit; a first scale is provided on one of the fixed member and the support member, and a first sensor is provided on the other of the fixed member and the support member; a second scale is provided on one of the fixed member and the output member, and a second sensor is provided on the other of the fixed member and the output member; a substrate is provided on the fixed member or the support member and the output member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; the first sensor and the second sensor are provided on a surface of the substrate facing the first scale and the second scale, the processing unit acquires a relative displacement between the fixed member and the support member using the first scale and the first sensor, acquires a relative displacement between the fixed member and the output member using the second scale and the second sensor, and acquires information about the torque based on the acquired results. A detection device characterized by:

27. ​​When the substrate is provided on the fixed member, the first scale is provided on the support member, and the second scale is provided on the output member; the first sensor and the second sensor are provided on a surface of the substrate facing the first scale provided on the support member and the second scale provided on the output member, 27. The detection device of claim 26.

28. The first sensor and the second sensor are provided on the same surface of the substrate facing the first scale and the second scale, 28. The detection device of claim 27.

29. A detection device that detects information about a torque of an output member that moves by driving a motor and a reducer that reduces the speed of the motor and outputs torque, the detection device includes a fixed member on which the motor is provided, an output member driven by the motor and the reducer and moving relative to the fixed member, a support member provided on the reducer and connected to the fixed member by an elastic body and movable relative to the fixed member, and a processing unit; a first scale is provided on one of the fixed member and the output member, and a first sensor is provided on the other of the fixed member and the output member; a second scale is provided on one of the support member and the output member, and a second sensor is provided on the other of the support member and the output member; a substrate is provided on the output member or the fixed member and the support member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; the processing unit acquires a relative displacement between the fixed member and the output member using the first scale and the first sensor, acquires a relative displacement between the output member and the support member using the second scale and the second sensor, and acquires information about the torque based on the acquired results. A detection device characterized by:

30. The first sensor and the second sensor are provided on a surface of the substrate facing the first scale and the second scale, 30. The detection device of claim 29.

31. When the substrate is provided on the output member, the first scale is provided on the fixing member, and the second scale is provided on the support member; the first sensor and the second sensor are provided on a surface of the substrate facing the first scale provided on the fixing member and the second scale provided on the support member, Detecting device according to claim 29 or 30.

32. The first sensor and the second sensor are provided on the same surface of the substrate facing the first scale and the second scale, 32. Detection device according to any one of claims 29 to 31.

33. A processing method for a detection device that detects information about a torque of an output member that moves when driven by a motor and outputs torque, comprising: the detection device includes a fixed member on which the motor is provided, a support member driven by the motor and movable relative to the fixed member, an output member connected to the support member by an elastic body and movable relative to the support member, and a processing unit; a first scale is provided on one of the fixed member and the support member, and a first sensor is provided on the other of the fixed member and the support member; a second scale is provided on one of the fixed member and the output member, and a second sensor is provided on the other of the fixed member and the output member; a substrate is provided on the fixed member or the support member and the output member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; the first sensor and the second sensor are provided on a surface of the substrate facing the first scale and the second scale, the processing unit acquires a relative displacement between the fixed member and the support member using the first scale and the first sensor, acquires a relative displacement between the fixed member and the output member using the second scale and the second sensor, and acquires information about the torque based on the acquired results. A processing method characterized by:

34. A processing method for a detection device that detects information about torque in an output member that moves by driving a motor and a reducer that decelerates driving of the motor and outputs torque, comprising: the detection device includes a fixed member on which the motor is provided, an output member driven by the motor and the reducer and moving relative to the fixed member, a support member provided on the reducer and connected to the fixed member by an elastic body and movable relative to the fixed member, and a processing unit; a first scale is provided on one of the fixed member and the output member, and a first sensor is provided on the other of the fixed member and the output member; a second scale is provided on one of the support member and the output member, and a second sensor is provided on the other of the support member and the output member; a substrate is provided on the output member or the fixed member and the support member, and the first sensor and the second sensor are provided on the substrate; the first sensor is provided on the substrate to face the first scale, and the second sensor is provided on the substrate to face the second scale; the processing unit acquires a relative displacement between the fixed member and the output member using the first scale and the first sensor, acquires a relative displacement between the output member and the support member using the second scale and the second sensor, and acquires information about the torque based on the acquired results. A processing method characterized by:

35. A program that can be executed by a computer to perform the control method according to claim 24 or 25 or the processing method according to claim 33 or 34.

36. A computer-readable recording medium storing the program according to claim 35.

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