Multi-axis force and torque sensor and robot having the same

Patent metadata

Field	Value
Publication number	US-11287340-B2
Application number	US-201916456588-A
Country	US
Kind code	B2
Filing date	Jun 28, 2019
Priority date	Jul 2, 2018
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A multi-axis force and torque sensor and a robot are provided. The sensor includes a first supporting element, a second supporting element, a deformable component connected between the first supporting element and the second supporting element, and multiple signal pairs. The deformable component is configured to deflect in response to applied external force and torque in multiple directions. Each of the multiple signal pairs includes a magnet and a hall effect detector. The magnet is mounted on one of the first supporting element and the second supporting element, and the hall effect detector is mounted on the other. The hall effect detector is located corresponding to the respective magnet. One or more magnetization directions of the magnets of the signal pairs are different such that the signal pairs are capable of measuring force and torque applied on the first supporting element and the second supporting element in different directions.

First claim

What is claimed is:

1. A multi-axis force and torque sensor, comprising:
a first supporting element including a first disk and a third disk;
a second supporting element including a second disk and a fourth disk, wherein the first disk, the second disk, the third disk, and the fourth disk are substantially parallel to each other;
a deformable component including (i) a first flexure element connecting the first disk to the second disk and (ii) a second flexure element connecting the third disk to the fourth disk, the deformable component configured to deflect in response to applied external force and torque in multiple directions; and
a plurality of signal pairs, each including a magnet and a hall effect detector,
wherein the magnet is mounted on one of the first supporting element and the second supporting element,
wherein the hall effect detector is mounted on the other of the first supporting element and the second supporting element, and is located corresponding to the respective magnet,
wherein the magnetization directions of the magnets of the plurality of signal pairs are different such that the plurality of signal pairs are capable of measuring force and torque applied on the first supporting element and the second supporting element in different directions, and
wherein the first disk and the second disk cooperatively constitute an upper sensing assembly and the third disk and fourth disk cooperatively constitute a lower sensing assembly, and the upper sensing assembly is stacked on the lower sensing assembly.

2. The sensor of claim 1 , wherein
the plurality of signal pairs include six signal pairs,
the magnetization directions of the magnets of three of the six signal pairs are parallel to a circumferential direction of the sensor, and
the magnetization directions of the magnets of the other three of the six signal pairs are parallel to an axial direction of the sensor.

3. The sensor of claim 1 , further comprising:
a plurality of first bridging structures rigidly connecting the first disk and the third disk, and
a plurality of second bridging structures rigidly connecting the second disk and the fourth disk.

4. The sensor of claim 3 , wherein each of the plurality of first and second bridging structures includes high magnetic permeability material, and is located corresponding to and at least partially enclosing a respective one of the plurality of signal pairs.

5. The sensor of claim 3 , wherein
each of the plurality of first bridging structures includes a first stop block spaced apart from the second disk in an axial direction of the sensor, the first stop block configured to prevent the first flexure element from over deflection in the axial direction, and
each of the plurality of second bridging structures includes a second stop block spaced apart from the third disk in the axial direction of the sensor, the second stop block configured to prevent the second flexure element from over deflection in the axial direction.

6. The sensor of claim 5 , further comprising:
a first dowel pin extending from the second disk and passing through the first disk, wherein there is clearance between the first dowel pin and the first disk in an extending direction of the first disk, and wherein the first dowel pin is configured to prevent the first flexure element from over deflection in a radial direction and a circumferential direction of the sensor; and
a second dowel pin extending from the third disk and passing through the fourth disk, wherein there is clearance between the second dowel pin and the fourth disk in an extending direction of the fourth disk, and wherein the second dowel pin is configured to prevent the second flexure element from over deflection in a radial direction and a circumferential direction of the sensor.

7. The sensor of claim 1 , further comprising:
a top case connected to the first supporting element;
a bottom case connected to the second supporting element; and
a seal connected between the top case and the bottom case, wherein the top case, the bottom case, and the seal cooperatively enclose the first supporting element, the second supporting element, the deformable component, and the plurality of signal pairs.

8. A multi-axis force and torque sensor, comprising an upper sensing assembly and a lower sensing assembly stacked together, wherein
the upper sensing assembly comprises:
a first disk;
a second disk;
a first flexure element connected between the first disk and the second disk, the first flexure element configured to deflect in response to applied external force and torque in multiple directions; and
a plurality of first signal pairs, each including a first signal emitter and a first signal receiver, wherein the first signal emitter is mounted on one of the first disk and the second disk, and the first signal receiver is mounted on the other of the first disk and the second disk and located corresponding to the first signal emitter; and

the lower sensing assembly comprises:
a third disk;
a fourth disk;
a second flexure element connected between the third disk and the fourth disk, of the second flexure element configured to deflect in response to applied external force and torque in multiple directions; and
a plurality of second signal pairs, each including a second signal emitter and a second signal receiver, wherein the second signal emitter is mounted on one of the third disk and the fourth disk, and the second signal receiver is mounted on the other of the third disk and the fourth disk and located corresponding to the second signal emitter,

wherein the first and second signal pairs are arranged differently such that the first signal pairs and the second signal pairs are configured to measure the applied external force and torque in multiple directions.

9. The sensor of claim 8 , wherein the first signal emitter and the second signal emitter are magnets, and the first signal receiver and the second signal receiver are hall effect detectors.

10. The sensor of claim 9 , wherein
a magnetization direction of the first signal emitter of each of the plurality of first signal pairs is parallel to a circumferential direction of the sensor;
a magnetization direction of the second signal emitter of each of the plurality of second signal pairs is parallel to an axial direction of the sensor.

11. The sensor of claim 8 , further comprising:
a plurality of first bridging structures rigidly connecting the first disk and the third disk; and
a plurality of second bridging structures rigidly connecting the second disk and the fourth disk.

12. The sensor of claim 11 , wherein
each of the first bridging structures includes a first stop block spaced apart from the second disk in an axial direction of the sensor, the first stop block configured to prevent the first flexure element from over deflection in the axial direction, and
each of the second bridging structures includes a second stop block spaced apart from the third disk in the axial direction of the sensor, the second stop block configured to prevent the second flexure element from over deflection in the axial direction.

13. The sensor of claim 12 , further comprising:
a first dowel pin extending from the second disk and passing through the first disk, wherein there is clearance between the first dowel pin and the first disk in an extending direction of the first disk, and wherein the first dowel pin is configured to prevent the first flexure element from over deflection in a radial direction and a circumferential direction of the sensor; and
a second dowel pin extending from the third disk and passing through the fourth disk, where

Assignees

• Flexiv Ltd

Inventors

• Jiang Hao
• Wang Shiquan

Classifications

• G01L1/12

  by measuring variations in the magnetic properties of materials resulting from the application of stress · CPC title

• G01L3/1435

  involving magnetic or electromagnetic means · CPC title

• G01L5/16 Primary

  for measuring several components of force · CPC title

• G01L1/122 Primary

  by using permanent magnets · CPC title

• G01L3/101

  involving magnetic or electromagnetic means · CPC title