WO2021187342A1 - トルクセンサおよびロボット関節構造 - Google Patents

トルクセンサおよびロボット関節構造 Download PDF

Info

Publication number
WO2021187342A1
WO2021187342A1 PCT/JP2021/009960 JP2021009960W WO2021187342A1 WO 2021187342 A1 WO2021187342 A1 WO 2021187342A1 JP 2021009960 W JP2021009960 W JP 2021009960W WO 2021187342 A1 WO2021187342 A1 WO 2021187342A1
Authority
WO
WIPO (PCT)
Prior art keywords
resistance element
sensor
strain
torque
inner ring
Prior art date
Application number
PCT/JP2021/009960
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
岡田　亮二
Original Assignee
株式会社グローセル
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社グローセル filed Critical 株式会社グローセル
Priority to CN202180021441.8A priority Critical patent/CN115280122A/zh
Priority to JP2022508303A priority patent/JP7360542B2/ja
Publication of WO2021187342A1 publication Critical patent/WO2021187342A1/ja

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J17/00—Joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
    • B25J19/02—Sensing devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
    • G01L3/02—Rotary-transmission dynamometers
    • G01L3/14—Rotary-transmission dynamometers wherein the torque-transmitting element is other than a torsionally-flexible shaft

Definitions

  • the present invention relates to a torque sensor and a robot joint structure, and relates to, for example, a technique that is effective when applied to a torque sensor that is a component of the robot joint structure.
  • Patent Document 1 describes a technique for correcting a sensor detection error caused by interference of other axes at a joint of a robot arm.
  • an articulated robot for collaborating with a human acts, in particular, around the drive shaft among the forces (including torque) acting on the robot arm. It is equipped with a torque sensor that detects torque.
  • This torque sensor is required to detect the torque acting around the drive shaft with high sensitivity in order to detect a slight contact reaction force with a human, but with the current technology, other than the drive shaft
  • a torque sensor that detects the torque acting around the drive shaft with high sensitivity is desired. That is, in the torque sensor that detects the torque acting around the drive shaft, it is desired to reduce the noise caused by the torque around the shaft other than the drive shaft and the force applied in each shaft direction.
  • An object of the present invention is to provide a torque sensor capable of detecting torque acting around a drive shaft with high sensitivity.
  • the torque sensor in one embodiment includes an inner ring portion, an outer ring portion, a plurality of connection portions connecting the inner ring portion and the outer ring portion, and a plurality of strain sensors that capture distortion as a change in resistance value.
  • the plurality of connecting portions are arranged on the first virtual line passing through the center of the inner ring of the inner ring portion, and the first connecting portion and the third connecting portion arranged on opposite sides to the center of the inner ring, respectively.
  • the plurality of strain sensors include a first strain sensor arranged on the first connection portion, a second strain sensor arranged on the second connection portion, and a third strain arranged on the third connection portion. It has a sensor and a fourth strain sensor disposed on the fourth connection.
  • each of the plurality of strain sensors has a semiconductor substrate that overlaps with the third virtual line in a plan view and a plurality of resistance elements formed on the semiconductor substrate, and the plurality of resistance elements are the first resistance element. , Includes a second resistance element.
  • the first angle formed by the first resistance element and the second resistance element is a right angle, and the third virtual line extends in a direction that bisects the first angle.
  • the first strain sensor among the plurality of strain sensors is arranged on the first connection portion so that the third virtual line coincides with the first virtual line
  • the second strain sensor among the plurality of strain sensors is arranged. Is arranged on the second connection portion so that the third virtual line coincides with the second virtual line.
  • the third virtual line coincides with the first virtual line, and the first resistance element of the third strain sensor with respect to the center of the inner ring is the first strain sensor.
  • the second resistance element of the third strain sensor is point-symmetric with the first resistance element and the second resistance element of the third strain sensor is point-symmetric with respect to the center of the inner ring.
  • the fourth strain sensor among the plurality of strain sensors the third virtual line coincides with the second virtual line, and the first resistance element of the fourth strain sensor with respect to the center of the inner ring is the second strain sensor.
  • Arranged on the fourth connection portion so as to be point-symmetric with the first resistance element and point-symmetric with the second resistance element of the second strain sensor with respect to the center of the inner ring. Has been done.
  • the torque sensor in the modified example includes an inner ring portion, an outer ring portion, a plurality of connection portions connecting the inner ring portion and the outer ring portion, and a plurality of strain sensors that capture distortion as a change in resistance value.
  • the plurality of connecting portions are arranged on the first virtual line passing through the center of the inner ring of the inner ring portion, and the first connecting portion and the fourth connecting portion arranged on opposite sides to the center of the inner ring, respectively.
  • a second connection that is a second A virtual line that passes through the center of the inner ring of the inner ring portion and is arranged on the second A virtual line that intersects the center of the inner ring with the first virtual line, and is arranged on opposite sides to the center of the inner ring.
  • the plurality of strain sensors include a first strain sensor arranged on the first connection portion, a second distortion sensor arranged on the second connection portion, and a third strain arranged on the third connection portion. It has a sensor, a fourth distortion sensor arranged on the fourth connection portion, a fifth distortion sensor arranged on the fifth connection portion, and a sixth distortion sensor arranged on the sixth connection portion.
  • each of the plurality of strain sensors has a semiconductor substrate that overlaps with the third virtual line in a plan view and a plurality of resistance elements formed on the semiconductor substrate, and the plurality of resistance elements are the first resistance element. , Includes a second resistance element.
  • the first angle formed by the first resistance element and the second resistance element is a right angle, and the third virtual line extends in a direction that bisects the first angle.
  • the first strain sensor among the plurality of strain sensors is arranged on the first connection portion so that the third virtual line coincides with the first virtual line
  • the second strain sensor among the plurality of strain sensors is arranged. Is arranged on the second connection so that the third virtual line coincides with the second A virtual line, and in the third distortion sensor among the plurality of distortion sensors, the third virtual line coincides with the second B virtual line. It is arranged on the second connection portion as described above.
  • the third virtual line coincides with the first virtual line
  • the first resistance element of the fourth strain sensor with respect to the center of the inner ring is the first strain sensor.
  • the second resistance element of the fourth strain sensor is point-symmetric with the first resistance element and the second resistance element of the fourth strain sensor is point-symmetric with respect to the center of the inner ring.
  • the third virtual line coincides with the second A virtual line
  • the first resistance element of the fifth strain sensor with respect to the center of the inner ring is the second strain sensor.
  • the second resistance element of the fifth strain sensor is point-symmetric with the first resistance element and the second resistance element of the second strain sensor is point-symmetric with respect to the center of the inner ring.
  • the third virtual line coincides with the second B virtual line
  • the first resistance element of the sixth distortion sensor with respect to the center of the inner ring is the third distortion sensor.
  • the second resistance element of the sixth strain sensor is point-symmetric with the first resistance element and the second resistance element of the sixth strain sensor is point-symmetric with respect to the center of the inner ring. Has been done.
  • the torque acting around the drive shaft can be detected with high sensitivity.
  • FIG. 23 It is a figure which shows typically the robot joint structure which applied the torque sensor in embodiment. It is an enlarged view of the connection part of a torque sensor and a link. It is a schematic view seen from the arrow direction of FIG. It is a schematic view seen from the AA plane of FIG. 23. It is a schematic view seen from the BB plane of FIG. 23. It is a graph which qualitatively shows the relationship between a surface pressure and a coefficient of static friction. (A) is a diagram showing how the bolt is deformed by applying torque or force to the torque sensor, and (b) is a diagram showing how the "bolt / outer ring portion surface" is slipped. .. FIGS.
  • FIGS. 1 and (B) are diagrams for explaining a mechanism in which the accuracy of detecting torque around the drive shaft by the torque sensor becomes unstable when the "bolt / outer ring portion surface" slips. It is a figure for demonstrating the device for improving the stability of the torque detection accuracy in a torque sensor. It is a top view which shows the structure of the torque sensor in the modification. It is a table explaining the application example of the basic idea to the modification example.
  • FIG. 1 is a schematic diagram showing an example of a robot system.
  • the robot system 1 includes, for example, a robot arm 10 configured as an articulated robot arm and a robot control unit 11 that controls the operation of the robot arm 10.
  • the robot arm 10 has a plurality of rotatable joint structures, and these plurality of joint structures are configured to be controlled by the robot control unit 11.
  • An end effector composed of, for example, an electric hand is connected to the tip of the robot arm 10.
  • the robot control unit 11 controls the operation of the joint structure of the robot arm 10 and the operation of the end effector. As a result, the work can be operated by the robot arm 10.
  • FIG. 2 is a diagram schematically showing a robot joint structure.
  • the robot joint structure 20 is a structure that connects the link 21A of the robot arm 10 and the link 21B of the robot arm 10.
  • a motor 22 is arranged inside the link 21A, and a speed reducer 23 is connected to the motor 22.
  • the motor 22 and the speed reducer 23 form a drive unit 24 of the robot joint structure 20.
  • a torque sensor 30 is connected to the speed reducer 23, and a link 21B is connected to the torque sensor 30.
  • a lubricating member 25 is provided between the speed reducer 23 and the torque sensor 30.
  • the torque sensor 30 connected to the speed reducer 23 constituting the drive unit 24 and the link 21B are integrated by rotating the motor 22 constituting the drive unit 24. Rotate around the drive shaft.
  • the torque sensor 30 has a function of detecting the torque around the drive shaft when the link 21B is rotated around the drive shaft. Specifically, the torque sensor 30 is configured to be deformed when the link 21B is rotated around the drive shaft, and the distortion based on this deformation is detected by a change in the electric resistance value (change in voltage). It is configured to calculate the torque around the drive shaft based on the detected change in the electric resistance value.
  • the deformation of the torque sensor 30 is caused not only by the torque around the drive shaft but also by the torque around other shafts other than the drive shaft and the force applied in each shaft direction.
  • changes in the electrical resistance value detected by the torque sensor 30 include not only changes due to distortion based on torque around the drive shaft, but also torque around other shafts other than the drive shaft and forces applied in each axial direction. It means that the change due to the distortion based on is also included. That is, the change in the electric resistance value due to the torque around the other shafts other than the drive shaft and the strain based on the force applied in each shaft direction becomes noise when calculating the torque around the drive shaft.
  • the torque sensor 30 in order for the torque sensor 30 to detect the torque around the drive shaft with high sensitivity, it is necessary to sufficiently reduce the noise caused by the torque around the shaft other than the drive shaft and the force applied in each shaft direction. .. That is, it is desired that the torque sensor 30 for detecting the torque acting around the drive shaft with high accuracy reduces the noise caused by the torque around the shaft other than the drive shaft and the force applied in each shaft direction. ing.
  • the "related technology” referred to in the present specification is a technology having a problem newly found by the inventor, and is not a known conventional technology, but is intended as a prerequisite technology (unknown technology) of a new technical idea. It is a technique described in.
  • FIG. 3 is a schematic diagram showing a robot joint structure in a related technology.
  • a bearing member 26 is provided between the speed reducer 23 constituting the drive unit 24 and the torque sensor 30.
  • the bearing member 26 is configured to rotate around the drive shaft together with the torque sensor 30, while fixing and supporting the torque sensor 30. That is, in the related technology, the torque sensor 30 is fixedly supported by the bearing member 26, so that the torque sensor 30 is not easily deformed except around the drive shaft. As a result, in the related technology, the torque sensor 30 is less likely to be deformed due to the torque around other shafts other than the drive shaft and the force applied in each shaft direction.
  • the torque sensor 30 detects the torque around the drive shaft, it is possible to reduce the noise caused by the torque around the other shafts other than the drive shaft and the force applied in each shaft direction. Means. That is, according to the related technology, it is considered that the torque around the drive shaft can be detected with high accuracy.
  • the mass of the robot joint structure 20A becomes large. That is, it is desirable that the mass of the robot joint structure 20A is small, but in the related technology, the mass of the robot joint structure 20A becomes large, and the operation of the robot joint structure 20A may become dull. Further, since it is necessary to newly provide the bearing member 26, the component cost of the robot joint structure 20A will increase. Therefore, it can be seen that the related technology can detect the torque around the drive shaft with high accuracy, but there is room for improvement from the viewpoint of improving the motion agility of the robot joint structure 20A and reducing the component cost. ..
  • a device is devised to realize a torque sensor 30 that can detect the torque around the drive shaft with high accuracy without using the bearing member 26.
  • a torque sensor 30 that can detect the torque around the drive shaft with high accuracy without using the bearing member 26.
  • FIG. 4 is a schematic diagram showing an example of setting coordinate axes. As shown in FIG. 4, the x-axis, y-axis, and z-axis that are orthogonal to each other are set as three-dimensional coordinates.
  • the force acting in the x-axis direction is represented by "Fx”
  • the force acting in the y-axis direction is represented by "Fy”
  • the force acting in the z-axis direction is represented by "Fz”.
  • the x-axis torque caused by the rotation around the x-axis is represented by "Tx”
  • the y-axis torque caused by the rotation around the y-axis is represented by “Ty”
  • the z-axis torque caused by the rotation around the z-axis is represented by "Ty”. It is represented by "Tz”.
  • the drive shaft is the z-axis. Therefore, the torque around the drive shaft is the z-axis torque around the z-axis, and the torque sensor 30 in the present embodiment aims to detect the z-axis torque around the z-axis with high accuracy.
  • the torque around the other axes other than the drive axis is the x-axis torque "Tx” or the y-axis torque "Ty”, and the force applied in each axis direction is the force in the x-axis direction.
  • They are "Fx”, a force in the y-axis direction “Fy”, and a force in the z-axis direction "Fz”.
  • FIG. 5 is a plan view showing the configuration of the torque sensor according to the present embodiment.
  • the torque sensor 100 includes an inner ring portion 110 composed of a circular ring, an outer ring portion 120 composed of a circular ring having a diameter larger than that of the inner ring portion 110, and an inner ring portion 110 and an outer ring portion 120. It is provided with a plurality of spokes (connection portions) 130 for connecting the above.
  • the plurality of spokes 130 are the spokes 130A and the spokes 130C arranged on the first virtual line VL1 passing through the inner ring center CP of the inner ring portion 110 and arranged on opposite sides to the inner ring center CP.
  • the torque sensor 100 configured in this way is equipped with a plurality of strain sensors 200 that capture distortion as a change in electrical resistance value.
  • the torque sensor 100 is equipped with four strain sensors 200. More specifically, the four strain sensors 200 include a first strain sensor 200A arranged on the spokes 130A, a second strain sensor 200B arranged on the spokes 130B, and a second strain sensor 200B arranged on the spokes 130C. A third strain sensor 200C and a fourth strain sensor 200D arranged on the spokes 130D are included.
  • FIG. 6 is a cross-sectional view taken along the line AA of FIG.
  • the inner ring portion 110 and the outer ring portion 120 are connected by the spokes 130B and the spokes 130D
  • the second strain sensor 200B is arranged on the spokes 130B
  • the fourth strain is placed on the spokes 130D. It can be seen that the sensor 200D is arranged.
  • the torque sensor 100 is configured.
  • the torque sensor 100 is deformed when a torque around each axis or a force in each axial direction is applied.
  • the spokes 130 of the torque sensor 100 are deformed when a torque around each axis or a force in each axial direction is applied, and the strain sensor 200 arranged on the spokes 130 is distorted due to the deformation of the spokes 130.
  • the strain sensor 200 captures the generated strain as a change in the electrical resistance of the resistance element.
  • the basic idea in the present embodiment is to devise the arrangement of a plurality of resistance elements formed in the strain sensor 200, and to devise the first strain sensor 200A, the second strain sensor 200B, the third strain sensor 200C, and the fourth strain sensor.
  • the arrangement of the four strain sensors 200 made of 200D only the strain caused by the torque around the drive shaft is extracted, while the strain caused by the torque around other shafts other than the drive shaft and the distortion in each axial direction It is an idea that offsets the distortion caused by the applied force.
  • the basic idea in the present embodiment is caused not only by the torque around the drive shaft but also by the torque around the drive shaft even when the torque around the other shafts other than the drive shaft and the force in each shaft direction are applied.
  • the idea is to devise the arrangement of a plurality of resistance elements formed in the distortion sensor 200 and to devise the arrangement of the four distortion sensors 200 so as to extract only the distortion and cancel the other distortions.
  • the concept of the basic idea will be explained below.
  • FIG. 7 is a table for explaining the basic idea in this embodiment in an easy-to-understand manner.
  • the first strain sensor 200A by devising the arrangement of the resistance element formed in the first strain sensor 200A and devising the arrangement of the first strain sensor 200A, it is caused by the x-axis torque around the x-axis.
  • the strain to be generated is "zero"
  • the strain caused by the y-axis torque around the y-axis is " ⁇ Ty "
  • the strain caused by the z-axis torque around the z-axis is " ⁇ Tz "
  • the strain caused by the force in the x-axis direction Is " ⁇ Fx "
  • the strain caused by the force in the y-axis direction is "zero”
  • the strain caused by the force in the z-axis direction is "zero".
  • the distortion caused by the x-axis torque around the x-axis is devised. Is " ⁇ Tx ", the strain caused by the y-axis torque around the y-axis is "zero”, the strain caused by the z-axis torque around the z-axis is " ⁇ Tz ", and the strain caused by the force in the x-axis direction is "”. "Zero”, the strain caused by the force in the y-axis direction is " ⁇ Fy ", and the strain caused by the force in the z-axis direction is "zero".
  • the distortion caused by the x-axis torque around the x-axis is devised. Is "zero", the strain caused by the y-axis torque around the y-axis is "- ⁇ Ty ", the strain caused by the z-axis torque around the z-axis is " ⁇ Tz ", and the strain caused by the force in the x-axis direction is "- ⁇ Ty". "- ⁇ Fx ", the strain caused by the force in the y-axis direction is "zero”, and the strain caused by the force in the z-axis direction is "zero".
  • the fourth strain sensor 200D by devising the arrangement of the resistance elements formed in the fourth strain sensor 200D and devising the arrangement of the fourth strain sensor 200D, it is caused by the x-axis torque around the x-axis.
  • the strain is "- ⁇ Tx "
  • the strain caused by the y-axis torque around the y-axis is "zero”
  • the strain caused by the z-axis torque around the z-axis is " ⁇ Tz "
  • the strain caused by the force in the x-axis direction Is "zero”
  • the strain caused by the force in the y-axis direction is "- ⁇ Fy "
  • the strain caused by the force in the z-axis direction is "zero".
  • the strains generated by the first strain sensor 200A, the second strain sensor 200B, the third strain sensor 200C, and the fourth strain sensor 200D are added. Then, for example, the total strain caused by the x-axis torque around the x-axis is "zero", the total strain caused by the y-axis torque around the y-axis is "zero”, and the total strain caused by the z-axis torque around the z-axis is "zero".
  • the total strain other than the total strain caused by the z-axis torque around the z-axis is "zero".
  • the basic idea of the present embodiment is adopted, only the strain caused by the torque around the drive shaft is extracted, while the strain caused by the torque around the other shaft other than the drive shaft and the force applied in each axial direction are extracted. It means that the distortion caused by can be offset. Therefore, according to the basic idea in the present embodiment, not only the torque around the drive shaft but also the torque around the drive shaft and the torque around the drive shaft even when the torque around the other shafts other than the drive shaft and the force in each shaft direction are applied. As a result of being able to extract only the resulting strain and offset the other strains, it can be seen that the torque around the drive shaft can be calculated with high accuracy.
  • this device includes a device for arranging a plurality of resistance elements formed in the strain sensor 200 and four strain sensors 200 (first strain sensor 200A, second strain sensor 200B, and third strain sensor 200C). And the fourth strain sensor 200D) there is a device for the arrangement.
  • FIG. 8 is a plan view showing a strain sensor according to the present embodiment.
  • the strain sensor 200 has a rectangular semiconductor substrate 210.
  • the semiconductor substrate 210 is made of, for example, silicon (Si).
  • a plurality of resistance elements 300 are formed on the semiconductor substrate 210.
  • the semiconductor substrate 210 is formed with four resistance elements 300 including a resistance element 300A, a resistance element 300B, a resistance element 300C, and a resistance element 300D.
  • Each of these plurality of resistance elements 300 is, for example, a diffusion resistance element formed by introducing conductive impurities into the semiconductor substrate 210.
  • the first angle formed by the resistance element 300A and the resistance element 300D is a right angle
  • the third virtual line VL3 that overlaps with the semiconductor substrate 210 extends in a direction that bisects the first angle.
  • the angle formed by the resistance element 300A and the resistance element 300B is also a right angle
  • the angle formed by the resistance element 300B and the resistance element 300C is also a right angle
  • the angle formed by the resistance element 300C and the resistance element 300D is also a right angle. That is, the four resistance elements 300 are arranged so that the angles formed by each other are at right angles.
  • right angle means a case where the idea of intentionally making a right angle is included, and even if the actual value deviates from 90 degrees by an error. If the idea of making a right angle to the root is included, it shall be included in the "right angle” as used herein. To give a specific example of numerical values, for example, if the angle is 88 degrees to 92 degrees, it can be considered that there is an idea of making a right angle to the base, so that it is included in the "right angle” referred to in the present specification. can.
  • the number of resistance elements is not limited to four.
  • these plurality of sets of synthesis circuits are finally equivalent to the form shown in FIG.
  • FIG. 9 is a plan view showing the arrangement of the four strain sensors 200.
  • the first strain sensor 200A out of the four strain sensors 200 is arranged so that the third virtual line VL3 (see FIG. 8) coincides with the first virtual line VL1.
  • the second strain sensor 200B out of the four strain sensors 200 is arranged so that the third virtual line VL3 (see FIG. 8) coincides with the second virtual line VL2.
  • the third virtual line VL3 coincides with the first virtual line VL1 and the third distortion sensor with respect to the inner ring center CP.
  • the resistance element 300A of 200C is point-symmetric with the resistance element 300A of the first strain sensor 200A, and the resistance element 300B of the third strain sensor is point-symmetric with the resistance element 300B of the first distortion sensor 200A with respect to the inner ring center CP.
  • the resistance element 300C of the third strain sensor 200C is point-symmetrical to the resistance element 300C of the first strain sensor 200A with respect to the inner ring center CP, and the resistance element of the third strain sensor is point-symmetrical with respect to the inner ring center CP.
  • the 300D is arranged so as to be point-symmetrical with the resistance element 300D of the first strain sensor 200A. Further, in the fourth distortion sensor 200D out of the four strain sensors 200, the third virtual line VL3 (see FIG.
  • the resistance element 300A of the 200D is point-symmetrical to the resistance element 300A of the second strain sensor 200B, and the resistance element 300B of the fourth strain sensor 200D is pointed to the resistance element 300B of the second strain sensor 200B with respect to the inner ring center CP.
  • the resistance element 300C of the fourth strain sensor 200D is point-symmetric with respect to the resistance element 300C of the second strain sensor 200B with respect to the inner ring center CP, and the fourth strain sensor 200D is symmetrical with respect to the inner ring center CP.
  • the resistance element 300D is arranged so as to be point-symmetrical with the resistance element 300D of the second distortion sensor 200B.
  • the basic idea in the present embodiment is embodied by devising the arrangement of the four resistance elements 300 formed in the strain sensor 200 and devising the arrangement of the four strain sensors 200. Specifically, in the four strain sensors 200 in which the four resistance elements 300 shown in FIG. 8 are formed, these four strain sensors 200 are arranged as shown in FIG. It will be explained that the basic idea (see FIG. 7) in the above is embodied.
  • FIG. 10 is a schematic view showing the strain applied to the resistance element 300 formed in each of the four strain sensors 200 when the y-axis torque (“Ty”) around the y-axis is applied to the torque sensor 100. ..
  • the tensile strain is “+”
  • the compression strain is “ ⁇ ”
  • the output strain from the strain sensor 200 based on the strain applied to the four resistance elements 300 formed in each strain sensor 200 is “((. Distortion of the resistance element 300A + distortion of the resistance element 300C)-(distortion of the resistance element 300B + distortion of the resistance element 300D) ”.
  • the output distortion output from the first distortion sensor 200A is set to "+ ⁇ Ty ".
  • the same tensile strain occurs in the resistance element 300A, the resistance element 300B, the resistance element 300C, and the resistance element 300D.
  • the output distortion output from the second distortion sensor 200B becomes "0".
  • the same tensile strain is generated in the resistance element 300A, the resistance element 300B, the resistance element 300C, and the resistance element 300D.
  • the output distortion output from the fourth distortion sensor 200D becomes "0".
  • the four strain sensors 200 (first strain sensor 200A, second strain sensor 200B, third strain sensor 200C, and fourth strain sensor 200D) shown in FIG. 10 are used to rotate the y-axis as shown in FIG. It can be seen that the distortion caused by the y-axis torque is realized.
  • FIG. 11 is a schematic view showing the strain applied to the resistance element 300 formed in each of the four strain sensors 200 when a force (“Fy”) in the y-axis direction is applied to the torque sensor 100.
  • the tensile strain is “+”
  • the compression strain is “ ⁇ ”
  • the output strain from the strain sensor 200 based on the strain applied to the four resistance elements 300 formed in each strain sensor 200 is “((. Distortion of the resistance element 300A + distortion of the resistance element 300C)-(distortion of the resistance element 300B + distortion of the resistance element 300D) ”.
  • the same tensile strain is generated in the resistance element 300A, the resistance element 300B, the resistance element 300C, and the resistance element 300D.
  • the output distortion output from the first distortion sensor 200A becomes "0".
  • the output distortion output from the second distortion sensor 200B is set to "+ ⁇ Fy ".
  • the same tensile strain occurs in the resistance element 300A, the resistance element 300B, the resistance element 300C, and the resistance element 300D.
  • the output distortion output from the third distortion sensor 200C becomes "0".
  • the fourth strain sensor 200D tensile strain is generated in the resistance element 300A and the resistance element 300C, while compression strain is generated in the resistance element 300B and the resistance element 300D. As a result, the output distortion output from the fourth distortion sensor 200D becomes "- ⁇ Fy ".
  • the four strain sensors 200 (first strain sensor 200A, second strain sensor 200B, third strain sensor 200C, and fourth strain sensor 200D) shown in FIG. 11 are used in the y-axis direction shown in FIG. It can be seen that the distortion caused by the applied force is realized.
  • FIG. 12 is a schematic view showing the strain applied to the resistance element 300 formed in each of the four strain sensors 200 when the z-axis torque (“Tz”) around the z-axis is applied to the torque sensor 100. ..
  • the tensile strain is “+”
  • the compression strain is “ ⁇ ”
  • the output strain from the strain sensor 200 based on the strain applied to the four resistance elements 300 formed in each strain sensor 200 is “((. Distortion of the resistance element 300A + distortion of the resistance element 300C)-(distortion of the resistance element 300B + distortion of the resistance element 300D) ”.
  • the output distortion output from the first distortion sensor 200A is set to "+ ⁇ Tz ".
  • the four strain sensors 200 (first strain sensor 200A, second strain sensor 200B, third strain sensor 200C, and fourth strain sensor 200D) shown in FIG. 12 are used to rotate the z-axis as shown in FIG. It can be seen that the distortion caused by the z-axis torque is realized.
  • the torque sensor 100 has a calculation unit that calculates the torque around the normal axis that passes through the inner ring center CP and is perpendicular to the inner ring portion 110 based on the outputs from the four strain sensors 200 described above. That is, the torque sensor 100 is driven around the drive axis (z-axis) based on the output of the first strain sensor 200A, the output of the second strain sensor 200B, the output of the third strain sensor 200C, and the output of the fourth strain sensor 200D. ) Z-axis torque is calculated.
  • FIG. 13 is a functional block diagram of the calculation unit 500.
  • the calculation unit 500 includes a first voltage value input unit 501, a second voltage value input unit 502, a third voltage value input unit 503, a fourth voltage value input unit 504, and a voltage value addition unit 505. It has a drive shaft torque calculation unit 506, an output unit 507, and a data storage unit 508.
  • the first voltage value input unit 501 is configured to input the output voltage from the first distortion sensor 200A.
  • the first strain sensor 200A is configured to be distorted due to deformation of the torque sensor 100 based on torque or force, and the resistance value of the four resistance elements 300 provided inside this distortion. It is configured to be regarded as a change, and the resistance value change is converted into a voltage value and output.
  • the first voltage value input unit 501 is configured to be able to input the output voltage from the first distortion sensor 200A. Then, the first voltage value, which is the output voltage from the first distortion sensor 200A, is stored in the data storage unit 508.
  • the first voltage value input to the first voltage value input unit 501 is the difference between the resistance value of the resistance element 300A in the first distortion sensor 200A and the resistance value of the resistance element 300B and the first distortion sensor 200A. It corresponds to the first total value obtained by adding the difference between the resistance value of the resistance element 300C and the resistance value of the resistance element 300D.
  • the second voltage value input unit 502 is configured to input the output voltage from the second distortion sensor 200B.
  • the second strain sensor 200B is also configured to be distorted due to deformation of the torque sensor 100 based on torque or force, and the resistance value of the four resistance elements 300 provided inside this distortion. It is configured to be regarded as a change, and the resistance value change is converted into a voltage value and output.
  • the second voltage value input unit 502 is configured to be able to input the output voltage from the second distortion sensor 200B. Then, the second voltage value, which is the output voltage from the second distortion sensor 200B, is stored in the data storage unit 508.
  • the second voltage value input to the second voltage value input unit 502 is the difference between the resistance value of the resistance element 300A in the second distortion sensor 200B and the resistance value of the resistance element 300B and the second distortion sensor 200B. It corresponds to the second total value obtained by adding the difference between the resistance value of the resistance element 300C and the resistance value of the resistance element 300D.
  • the third voltage value input unit 503 is configured to input the output voltage from the third distortion sensor 200C.
  • the third strain sensor 200C is configured to be distorted due to deformation of the torque sensor 100 based on torque or force, and the resistance value of the four resistance elements 300 provided inside this distortion. It is configured to be regarded as a change, and the resistance value change is converted into a voltage value and output.
  • the third voltage value input unit 503 is configured to be able to input the output voltage from the third distortion sensor 200C. Then, the third voltage value, which is the output voltage from the third distortion sensor 200C, is stored in the data storage unit 508.
  • the third voltage value input to the third voltage value input unit 503 is the difference between the resistance value of the resistance element 300A in the third distortion sensor 200C and the resistance value of the resistance element 300B and the third distortion sensor 200C. It corresponds to the third total value obtained by adding the difference between the resistance value of the resistance element 300C and the resistance value of the resistance element 300D.
  • the fourth voltage value input unit 504 is configured to input the output voltage from the fourth distortion sensor 200D.
  • the fourth strain sensor 200D is configured to be distorted due to deformation of the torque sensor 100 based on torque or force, and the resistance value of the four resistance elements 300 provided inside this distortion. It is configured to be regarded as a change, and the resistance value change is converted into a voltage value and output.
  • the fourth voltage value input unit 504 is configured to be able to input the output voltage from the fourth distortion sensor 200D. Then, the fourth voltage value, which is the output voltage from the fourth distortion sensor 200D, is stored in the data storage unit 508.
  • the third voltage value input to the fourth voltage value input unit 504 is the difference between the resistance value of the resistance element 300A in the fourth distortion sensor 200D and the resistance value of the resistance element 300B and the fourth distortion sensor 200D. It corresponds to the fourth total value obtained by adding the difference between the resistance value of the resistance element 300C and the resistance value of the resistance element 300D.
  • the voltage value adding unit 505 uses the first voltage value input to the first voltage value input unit 501, the second voltage value input to the second voltage value input unit 502, and the third voltage value input unit. It is configured to calculate the total voltage value by adding the third voltage value input to the 503 and the fourth voltage value input to the fourth voltage value input unit 504.
  • the calculation of the total voltage value by the voltage value adding unit 505 corresponds to, for example, calculating the total shown in FIG. 7. That is, the total voltage value calculated by the voltage value addition unit 505 cancels out the distortion caused by the torque around the other shaft and the force applied in each shaft direction, and becomes the distortion caused only by the drive shaft torque around the drive shaft. It becomes the corresponding voltage value.
  • the drive shaft torque calculation unit 506 is configured to calculate the drive shaft torque around the drive shaft based on the total voltage value calculated by the voltage value addition unit 505.
  • the total voltage value calculated by the voltage value adding unit 505 cancels out the distortion caused by the torque around the other shaft and the force applied in each axial direction, and the drive shaft around the drive shaft. Since the voltage value corresponds to the distortion caused only by the torque, the drive shaft torque calculated based on the total voltage value is highly accurate. For example, there is a correlation between strain and an electrical resistance value, and there is also a correlation between a voltage value based on this electrical resistance value and strain. Since there is also a correlation between strain and torque, the voltage value and torque are also correlated.
  • the drive shaft torque calculation unit 506 can calculate the drive shaft torque from the total voltage value calculated by the voltage value addition unit 505 based on the formula or table stored in the data storage unit 508.
  • the output unit 507 is configured to output the value of the drive shaft torque calculated by the drive shaft torque calculation unit 506 to the outside.
  • the value of the drive shaft torque output from the output unit 507 is input to the robot control unit 11 shown in FIG. 1 and can be used for the operation control of the robot arm 10 by the robot control unit 11.
  • calculation unit 500 in the present embodiment is configured as described above, and the operation of the calculation unit 500 will be described below with reference to the drawings.
  • FIG. 14 is a flowchart illustrating the operation of the calculation unit.
  • the first voltage value input unit 501 inputs the first voltage value which is the output voltage from the first distortion sensor 200A
  • the second voltage value input unit 502 outputs from the second distortion sensor 200B.
  • the third voltage value input unit 503 inputs the third voltage value which is the output voltage from the third distortion sensor 200C
  • the fourth voltage value input unit 504 inputs the output voltage from the fourth distortion sensor 200D.
  • the fourth voltage value is input (S101).
  • the voltage value adding unit 505 adds the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value to calculate the total voltage value.
  • the drive shaft torque calculation unit 506 calculates the drive shaft torque based on the total voltage value calculated by the voltage value addition unit 505.
  • the value of the drive shaft torque calculated by the drive shaft torque calculation unit 506 is output from the output unit 507.
  • FIG. 15 is a graph showing the outputs from each of the four strain sensors when the y-axis torque (“Ty”) around the y-axis is applied.
  • the horizontal axis represents the magnitude of the y-axis torque (“Ty (Nm)”), while the vertical axis represents the output “strain amount ( ⁇ )” of each strain sensor.
  • the output (absolute value) from the first strain sensor increases as the y-axis torque increases.
  • the output from the first strain sensor is “15 ⁇ ”
  • the output from the first strain sensor is “200 Nm”
  • the output from the first strain sensor is "35 ⁇ ”.
  • the y-axis torque is "400 Nm”
  • the output from the first strain sensor is "60 ⁇ ”
  • the output from the first strain sensor is "90 ⁇ ".
  • the output (absolute value) from the third strain sensor increases as the y-axis torque increases.
  • the output from the first strain sensor is "-15 ⁇ ”
  • the output from the first strain sensor is "-15 ⁇ ”.
  • the output from the first strain sensor is "-15 ⁇ ". -35 ⁇ ”.
  • the output from the first strain sensor is "-60 ⁇ ”
  • the output from the first strain sensor is "600 Nm”
  • the output from the first strain sensor is "-60 ⁇ ". -90 ⁇ ”.
  • FIG. 16 is a graph showing the total output from the four strain sensors when the y-axis torque (“Ty”) around the y-axis is applied.
  • the horizontal axis shows the magnitude of the y-axis torque (“Ty (Nm)”), while the vertical axis shows the total output “strain amount ( ⁇ )” from the four strain sensors. ing.
  • the total output from the four strain sensors is almost "0" regardless of the magnitude of the y-axis torque. That is, from FIG. 16, for example, even if the y-axis torque around the y-axis, which is an example of the torque around the other shaft other than the drive shaft torque (z-axis torque) around the drive shaft, is added, the first one based on the y-axis torque. It can be seen that when the output from the strain sensor, the output from the second strain sensor, the output from the third strain sensor, and the output from the fourth strain sensor are added, the total output becomes almost "0". That is, it can be seen from the results shown in FIGS. 15 and 16 that the total output from the four strain sensors is not affected by the strain caused by the y-axis torque.
  • FIG. 17 is a graph showing changes in the average values of the outputs from the four strain sensors when a certain amount of z-axis torque is applied around the z-axis and further y-axis torque around the y-axis is applied. be.
  • the horizontal axis represents the magnitude of the y-axis torque (“Ty (Nm)”), while the vertical axis represents the average value of the output “strain amount ( ⁇ )” from the four strain sensors. Is shown. Further, each point indicates the magnitude of the z-axis torque (“Tz”). For example, “*” means that the z-axis torque is clockwise and is 600 (Nm). The “dotted line” has a z-axis torque ("Tz”) counterclockwise and is -600 (Nm).
  • the output from the first strain sensor 200A is the strain amount obtained by adding the strain amount “ ⁇ Ty ” due to the y-axis torque and the strain amount “ ⁇ Tz ” due to the z-axis torque. It becomes the corresponding output.
  • the output from the second strain sensor 200B is an output corresponding to the sum of the strain amount “ ⁇ Ty ” caused by the y-axis torque and the strain amount “ ⁇ Tz ” caused by the z-axis torque.
  • the output from the third strain sensor 200C is an output corresponding to the amount of strain obtained by adding the amount of strain "- ⁇ Ty " caused by the y-axis torque and the amount of strain " ⁇ Tz " caused by the z-axis torque. ..
  • the output from the fourth strain sensor 200D is an output corresponding to the strain amount obtained by adding the strain amount “ ⁇ Ty ” due to the y-axis torque and the strain amount “ ⁇ Tz ” due to the z-axis torque. ..
  • FIG. 18 is a diagram schematically showing a robot joint structure 20 to which the torque sensor 100 according to the present embodiment is applied.
  • the torque sensor 100 according to the present embodiment is connected to a drive unit 24 including a motor 22 and a speed reducer 23, and is also connected to a link 21B forming a part of a robot arm.
  • the drive shaft torque around the drive shaft can be detected with high accuracy by the torque sensor 100.
  • a bearing member 26 is provided between the drive unit 24 and the torque sensor 30.
  • the torque sensor 30 is fixedly supported by the bearing member 26 so that it is less likely to be deformed except around the drive shaft. That is, in the torque sensor 30 in the related technology, when the torque sensor 30 is deformed due to the torque around the other shafts other than the drive shaft and the force applied in each axial direction, the strain caused by this deformation is also detected by the torque sensor 30. As a result, the torque sensor 30 is easily affected by the torque around the other shafts other than the drive shaft and the noise caused by the force applied in each shaft direction.
  • the torque sensor 30 is fixedly supported by the bearing member 26 so that the torque sensor 30 is less likely to be deformed except around the drive shaft.
  • the torque sensor 30 is less likely to be deformed due to the torque around the other shafts other than the drive shaft and the force applied in each shaft direction. Therefore, the torque sensor 30 detects the torque around the drive shaft.
  • the torque sensor 30 is fixedly supported by the bearing member 26 to make the torque sensor 30 less likely to be deformed other than around the drive shaft, so that the torque around the drive shaft can be detected with high accuracy. ing.
  • the mass of the robot joint structure 20A becomes large. That is, it is desirable that the mass of the robot joint structure 20A is small, but in the related technology, the mass of the robot joint structure 20A becomes large, and the operation of the robot joint structure 20A may become dull. Further, since it is necessary to newly provide the bearing member 26, the component cost of the robot joint structure 20A will increase. Therefore, it can be seen that the related technology can detect the torque around the drive shaft with high accuracy, but there is room for improvement from the viewpoint of improving the motion agility of the robot joint structure 20A and reducing the component cost. ..
  • the torque sensor 100 can be used as a torque sensor 100 even if the torque sensor 100 is deformed due to torque around other shafts other than the drive shaft or a force applied in each axial direction.
  • the four strain sensors 200 provided cancel out the distortion caused by the torque around the other shafts other than the drive shaft and the force applied in each axial direction. That is, according to the torque sensor 100 in the present embodiment, even if the torque sensor 100 is deformed due to the torque around the other shaft other than the drive shaft and the force applied in each shaft direction, the other shaft other than the drive shaft Noise caused by the surrounding torque and the force applied in each axial direction is less likely to occur.
  • the torque sensor 100 in the present embodiment has torque around the drive shaft without suppressing deformation of the torque sensor 100 due to torque around other shafts other than around the drive shaft and forces applied in each axial direction. Can be detected with high accuracy.
  • the torque sensor 100 in the present embodiment it is not necessary to fix and support the bearing member 26 as in the torque sensor 30 of the related technique shown in FIG.
  • the torque sensor 100 in the present embodiment cancels out the distortion caused by the torque around the other shafts other than the drive shaft and the force applied in each shaft direction without being fixedly supported by the bearing member 26.
  • the torque around the drive shaft can be detected with high accuracy.
  • the bearing member 26 since the bearing member 26 is not required, it is possible to suppress an increase in the mass of the robot joint structure 20 itself. Therefore, according to the present embodiment, the motion agility of the robot joint structure can be improved by adopting the torque sensor 100. Furthermore, since it is not necessary to add a new component called the bearing member 26, it is possible to reduce the number of parts of the robot joint structure 20, which has the advantage of reducing the cost of parts.
  • the torque sensor 100 has high rigidity and is not excessively deformed by the moments of the x-axis, y-axis, and z-axis.
  • the thickness and width of the spokes 130 shown in FIG. 5 must be increased. Then, the strain generated by the z-axis torque becomes small, and the resolution of the z-axis torque to be measured is reduced. That is, the z-axis torque at the limit that can be detected becomes large.
  • the strain sensor 200 shown in FIG. 8 has a significantly higher sensitivity to a strain gauge that measures based on a general metal resistance change.
  • the strain sensor 200 is made of silicon, the gauge ratio indicating the sensitivity for detecting strain is about 25 times that of a general metallic strain gauge. Therefore, by using the strain sensor 200, the rigidity of the torque sensor 100 can be increased, and as a result, the bearing member 26 can be omitted.
  • the torque sensor 100 in the present embodiment has high accuracy in torque around the drive shaft without suppressing deformation of the torque sensor 100 due to torque around other shafts other than the drive shaft and forces applied in each axial direction. It is useful in that it can be detected in, and is effective, for example, by applying it to the robot joint structure 20. However, as a result of the study by the present inventor, it has been found that it is important to devise a connection structure between the torque sensor 100 and the link 21B when applying the torque sensor 100 to the robot joint structure 20. Explain the findings.
  • FIG. 21 is a diagram schematically showing a robot joint structure 20 to which the torque sensor 100 according to the present embodiment is applied.
  • the region RA shows the connection portion between the torque sensor 100 and the link 21B.
  • FIG. 22 is an enlarged view of the connection portion between the torque sensor 100 and the link 21B shown in the region RA.
  • the torque sensor 100 is formed with a through portion TH
  • the link 21B is formed with an opening OP having a thread.
  • the penetrating portion TH formed in the torque sensor 100 and the opening OP formed in the link 21B communicate with each other, and a bolt 600A is inserted into the penetrating portion TH and the opening OP.
  • the torque sensor 100 and the link 21B are connected.
  • an axial force "P" is applied to the bolt 600A.
  • FIG. 23 is a schematic view seen from the direction of the arrow in FIG. 22.
  • the torque sensor 100 and the link 21B are connected by a bolt 600A and a nut 600B.
  • FIG. 24 shows a schematic view seen from the AA plane of FIG. 23
  • FIG. 25 shows a schematic view seen from the BB plane of FIG. 23.
  • the AA surface is referred to as a "bolt / outer ring portion surface”
  • the BB surface is referred to as an "outer ring portion / link surface”.
  • the bolt 600A is fixed to the outer ring portion 120 of the torque sensor 100, and the contact surface between the bolt 600A and the outer ring portion 120 is indicated by “S1”.
  • P indicates the axial force applied to the bolt 600A
  • S1 indicates the contact area between the bolt 600A and the outer ring portion 120.
  • the outer ring portion 120 of the torque sensor 100 and the link 21B are fixed by bolts 600A, and the contact surface between the outer ring portion 120 and the link 21B is indicated by “S2”.
  • This "S2” corresponds to the entire surface of the outer ring portion 120.
  • P indicates the axial force applied to the bolt 600A
  • S2 indicates the contact area between the outer ring portion 120 and the link 21B.
  • the contact area “S2” between the outer ring portion 120 and the link 21B becomes small.
  • FIG. 26 is a graph qualitatively showing the relationship between the surface pressure and the coefficient of static friction.
  • the horizontal axis represents the surface pressure “ ⁇ ”, while the vertical axis represents the static friction coefficient “ ⁇ ”.
  • the static friction coefficient “ ⁇ ” becomes It can be seen that it tends to be smaller. That is, it can be seen that the larger the surface pressure “ ⁇ ”, the more slippery it becomes.
  • FIG. 27 is a schematic view showing how slippage occurs on the “bolt / outer ring portion surface”.
  • FIG. 27A shows, for example, how the bolt 600A is deformed by applying torque or force to the torque sensor 100.
  • the deformation of the bolt 600A is largely drawn for the sake of clarity.
  • slippage occurs on the "bolt / outer ring portion surface" as shown in FIG. 27 (b).
  • the present inventor has newly found that when the "bolt / outer ring portion surface" slips, the detection accuracy of the torque around the drive shaft by the torque sensor 100 becomes unstable.
  • FIG. 28A and 28 (b) are for explaining a mechanism in which the torque detection accuracy around the drive shaft of the torque sensor 100 becomes unstable when the “bolt / outer ring surface” slips. It is a figure.
  • FIG. 28A a force line in which a torque is applied to the torque sensor 100 and the torque is transmitted from the inner ring portion 110 to the outer ring portion 120 as a shearing force is indicated by an arrow.
  • the force line of the shearing force is transmitted from the inner ring portion 110 through the spokes 130 to the inside of the bolt 600A via the “bolt / outer ring portion surface” (first path).
  • the force line of the shearing force is transmitted to the link 21B via the "outer ring portion / link surface" (second path).
  • the force line of the shearing force flows through both the first path and the second path, and there is a "bolt / outer ring portion surface" in which slip is likely to occur in the first path. Therefore, if slippage occurs on the "bolt / outer ring portion surface", the force line of the shearing force flowing through the spokes 130 is disturbed.
  • a strain sensor 200 is arranged on the spokes 130, and since the strain sensor 200 measures the flow of the shearing force on the spokes 130, the force line of the shearing force flowing through the spokes 130 is disturbed. Then, the output from the distortion sensor 200 arranged on the spoke 130 is also disturbed. As a result, the torque detection accuracy of the torque sensor 100 becomes unstable. This finding is a finding newly found by the present inventor.
  • the present inventor has further devised a method for improving the stability of the torque detection accuracy of the torque sensor 100. In the following, this device will be described.
  • FIG. 29 is a diagram for explaining a device for improving the stability of the torque detection accuracy of the torque sensor.
  • the ingenuity is that a thread is formed in the penetrating portion TH provided in the outer ring portion 120 of the torque sensor 100, and the torque sensor 100 and the link 21B are fastened with a screw 700 instead of a bolt.
  • a screw hole is formed in the outer ring portion 120 of the torque sensor 100, and the outer ring portion 120 is a member (which can rotate integrally with the outer ring portion 120 by screwing a screw 700 into the screw hole). It is configured so that it can be fastened to the link 21B).
  • the stability of the torque detection accuracy of the torque sensor 100 can be improved. The reason for this will be described below.
  • the basic idea is to devise the arrangement of multiple strain sensors provided in the torque sensor and the arrangement of multiple resistance elements formed in each of the multiple strain sensors to eliminate only the distortion caused by the torque around the drive shaft.
  • the idea is to offset the distortion caused by the torque around the other shafts other than the drive shaft and the strain caused by the force applied in each axis direction.
  • a configuration of a torque sensor 100 including four strain sensors 200 as shown in FIG. 5 is adopted, and a plurality of strain sensors 200 formed in the strain sensor 200 as shown in FIG. 8 are formed. This is realized by adopting the layout arrangement of the resistance element 300.
  • the basic idea is not only the configuration described in the embodiment, but also the configuration of the torque sensor 100A including the six strain sensors 200 as shown in FIG. 30 and the distortion as shown in FIG. This can also be realized by the configuration of this modification in which the layout arrangement of the plurality of resistance elements 300 formed on the sensor 200 is adopted.
  • FIG. 30 is a plan view showing the configuration of the torque sensor 100A in this modified example.
  • the torque sensor 100A connects an inner ring portion 110 composed of a circular ring, an outer ring portion 120 composed of a circular ring having a diameter larger than that of the inner ring portion 110, and the inner ring portion 110 and the outer ring portion 120. It is provided with a plurality of spokes (connection portions) 130.
  • the plurality of spokes 130 are composed of six spokes 130, spokes 130A, spokes 130B, spokes 130C, spokes 130D, spokes 130E, and spokes 130F.
  • the spokes 130A and 130D are arranged on the first virtual line VL1 and on opposite sides of the inner ring center CP.
  • the spokes 130B and 130E are arranged on the virtual line VL2A, respectively, and are arranged on opposite sides to the inner ring center CP.
  • the spokes 130C and 130F are arranged on the virtual line VL2B, respectively, and are arranged on opposite sides to the inner ring center CP.
  • the first virtual line VL1, the virtual line VL2A, and the virtual line VL2B intersect at the inner ring center CP of the inner ring portion 110, and form an intersection angle of about 60 degrees. That is, in this modification, the first virtual line VL1, the virtual line VL2A, and the virtual line VL2B are not orthogonal to each other. Then, in FIG. 30, assuming that the virtual line orthogonal to the first virtual line VL1 is the second virtual line VL2, the second virtual line VL2 is a bisector of the virtual line VL2A and the virtual line VL2B. ..
  • strain sensors 200 are mounted on each of the six spokes 130.
  • the first strain sensor 200A is mounted on the spokes 130A
  • the second strain sensor 200B is mounted on the spokes 130B.
  • a third strain sensor 200C is mounted on the spokes 130C
  • a fourth strain sensor 200D is mounted on the spokes 130D.
  • a fifth distortion sensor 200E is mounted on the spokes 130E
  • a sixth distortion sensor 200F is mounted on the spokes 130F.
  • a plurality of resistance elements 300 are formed in the strain sensor 200 mounted on each of the six spokes 130.
  • the present modification is the same as that of the embodiment.
  • the first strain sensor 200A and the fourth strain sensor 200D are point-symmetric with respect to the inner ring center CP.
  • the second strain sensor 200B and the fifth strain sensor 200E are point-symmetric with respect to the inner ring center CP.
  • the third strain sensor 200C and the sixth strain sensor 200F are point-symmetrical with respect to the inner ring center CP.
  • the torque sensor 100A is configured.
  • FIG. 31 is a table for explaining an example of applying the basic idea to a modified example.
  • the distortion distortion resulting from x-axis torque about the x-axis is due to the "Ipushiron' Tx", y-axis torque around the y-axis is " ⁇ '' Ty ”, the strain caused by the z-axis torque around the z-axis is“ ⁇ Tz ”, the strain caused by the force in the x-axis direction is“ ⁇ ⁇ Fx ”, and the strain caused by the force in the y-axis direction is“ ⁇ Tz ”.
  • '' Fy the distortion caused by the force in the z-axis direction is“ zero ”.
  • the distortion caused by the x-axis torque around the x-axis is the strain caused by the "-Ipushiron' Tx"
  • y-axis torque about the y-axis is "-Ipushiron'' Ty "
  • distortion resulting from force in x-axis direction is "Ipushiron' Fx "
  • distortion resulting from forces in the y-axis direction Is "- ⁇ ” Fy " distortion caused by the force in the z-axis direction is” zero ".
  • the strain caused by the x-axis torque around the x-axis is "zero"
  • the strain caused by the y-axis torque around the y-axis is "- ⁇ Ty”.
  • the strain caused by the z-axis torque around the z-axis is " ⁇ Tz "
  • the strain caused by the force in the x-axis direction is "- ⁇ Fx”
  • the strain caused by the force in the y-axis direction is "zero”
  • z The distortion caused by the axial force is "zero".
  • the distortion caused by the x-axis torque around the x-axis is the strain caused by the "-Ipushiron' Tx"
  • y-axis torque about the y-axis is "-Ipushiron'' Ty "
  • distortion resulting from force in x-axis direction is "Ipushiron' Fx "
  • distortion resulting from forces in the y-axis direction Is "- ⁇ ” Fy " distortion caused by the force in the z-axis direction is” zero ".
  • the distortion distortion resulting from x-axis torque about the x-axis is due to the "Ipushiron' Tx", y-axis torque around the y-axis is " ⁇ '' Ty ”, the strain caused by the z-axis torque around the z-axis is“ ⁇ Tz ”, the strain caused by the force in the x-axis direction is“ ⁇ ⁇ Fx ”, and the strain caused by the force in the y-axis direction is“ ⁇ Tz ”.
  • '' Fy the distortion caused by the force in the z-axis direction is“ zero ”.
  • the strains generated by the first strain sensor 200A, the second strain sensor 200B, the third strain sensor 200C, the fourth strain sensor 200D, the fifth strain sensor 200E, and the sixth strain sensor 200F are added. do. Then, for example, the total strain caused by the x-axis torque around the x-axis is "zero", the total strain caused by the y-axis torque around the y-axis is "zero”, and the total strain caused by the z-axis torque around the z-axis is "zero".
  • the total strain other than the total strain caused by the z-axis torque around the z-axis is "zero".
  • the advantage of adopting the torque sensor 100 in the embodiment is that the cost can be reduced in that the basic idea can be realized with four strain sensors 200, which is less than the six strain sensors 200 as in this modification. Can be mentioned.
  • the advantage of adopting the torque sensor 100A in this modification is that the total strain due to the torque around the drive shaft (around the z-axis) is "4 ⁇ Tz " in the embodiment (see FIG. 7).
  • the total strain caused by the torque around the drive shaft (around the z-axis) can be set to "6 ⁇ Tz ", and as a result, the magnitude of the detection signal can be increased.
  • the strain sensor 200 in the present embodiment is composed of four resistance elements 300 (resistance element 300A, resistance element 300B, resistance element 300C, and resistance element 300D) arranged orthogonally to each other.
  • the technical idea in the present embodiment is not limited to this, and for example, in FIG. 8, two resistance elements 300 (resistance element 300A and resistance element 300D) arranged at right angles to each other. It can be widely applied to the case of configuring the strain sensor 200.

Landscapes

  • Engineering & Computer Science (AREA)
  • Robotics (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Manipulator (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)
PCT/JP2021/009960 2020-03-19 2021-03-12 トルクセンサおよびロボット関節構造 WO2021187342A1 (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202180021441.8A CN115280122A (zh) 2020-03-19 2021-03-12 扭矩传感器及机器人关节结构
JP2022508303A JP7360542B2 (ja) 2020-03-19 2021-03-12 トルクセンサ

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020-049389 2020-03-19
JP2020049389 2020-03-19

Publications (1)

Publication Number Publication Date
WO2021187342A1 true WO2021187342A1 (ja) 2021-09-23

Family

ID=77772054

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/009960 WO2021187342A1 (ja) 2020-03-19 2021-03-12 トルクセンサおよびロボット関節構造

Country Status (3)

Country Link
JP (1) JP7360542B2 (zh)
CN (1) CN115280122A (zh)
WO (1) WO2021187342A1 (zh)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4208522A1 (de) * 1992-03-18 1993-09-23 Hottinger Messtechnik Baldwin Drehmomentsensor
JP2016070673A (ja) * 2014-09-26 2016-05-09 株式会社レプトリノ 力覚センサ
JP2017203645A (ja) * 2016-05-09 2017-11-16 ソニー株式会社 トルクセンサ及び力制御型アクチュエータ
JP2019066373A (ja) * 2017-10-03 2019-04-25 アズビル株式会社 トルク検出装置
JP2019184466A (ja) * 2018-04-12 2019-10-24 株式会社小野測器 トルク計測装置
JP2020012657A (ja) * 2018-07-13 2020-01-23 日本電産コパル電子株式会社 トルクセンサ

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006220574A (ja) * 2005-02-14 2006-08-24 Hitachi Ltd 回転体力学量測定装置および回転体力学量計測システム

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4208522A1 (de) * 1992-03-18 1993-09-23 Hottinger Messtechnik Baldwin Drehmomentsensor
JP2016070673A (ja) * 2014-09-26 2016-05-09 株式会社レプトリノ 力覚センサ
JP2017203645A (ja) * 2016-05-09 2017-11-16 ソニー株式会社 トルクセンサ及び力制御型アクチュエータ
JP2019066373A (ja) * 2017-10-03 2019-04-25 アズビル株式会社 トルク検出装置
JP2019184466A (ja) * 2018-04-12 2019-10-24 株式会社小野測器 トルク計測装置
JP2020012657A (ja) * 2018-07-13 2020-01-23 日本電産コパル電子株式会社 トルクセンサ

Also Published As

Publication number Publication date
JPWO2021187342A1 (zh) 2021-09-23
JP7360542B2 (ja) 2023-10-12
CN115280122A (zh) 2022-11-01

Similar Documents

Publication Publication Date Title
US10422707B2 (en) Compact robotic force/torque sensor including strain gages
CN102785253B (zh) 具有机器人的异常检测功能的机器人系统及其控制方法
US11085836B2 (en) Force sensor that detects at least one of a force in each axial direction and a moment around each axis in an XYZ three-dimensional coordinate system
US11788906B2 (en) Force sensor
US20210086350A1 (en) Link actuating device
JP5640905B2 (ja) 起歪体及びこれを含む装置
JP2018132313A (ja) トルクセンサ
JP6664742B2 (ja) 力覚センサ
JP6585694B2 (ja) 歪みセンサ、多軸力センサおよびロボット
JP2006308577A (ja) 自動車ホイール用の軸受及び荷重測定方法
WO2021187342A1 (ja) トルクセンサおよびロボット関節構造
JP4249735B2 (ja) 力センサ
US10989614B2 (en) Torque sensor and robot
JPH05149811A (ja) ６軸力覚センサ
US20210060793A1 (en) Robotic arm and robot
KR20230128978A (ko) 토크 센서
JP6549812B2 (ja) トルクセンサおよびロボット
US11768118B2 (en) Force sensor
US20230266186A1 (en) Torque sensor element and torque sensor
US20200256750A1 (en) Force sensor
TW201939005A (zh) 轉矩感測器
CN115614452A (zh) 外齿齿轮、波动减速器以及机器人
JP7305364B2 (ja) 多軸センサ
US11872700B2 (en) Robot with a torque sensor and a force sensor
JP7421255B1 (ja) 力覚センサ

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21770457

Country of ref document: EP

Kind code of ref document: A1

DPE2 Request for preliminary examination filed before expiration of 19th month from priority date (pct application filed from 20040101)
ENP Entry into the national phase

Ref document number: 2022508303

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21770457

Country of ref document: EP

Kind code of ref document: A1