Instrumented tools for monitoring interaction dynamics during contact task

Patent metadata

Field	Value
Publication number	US-10449654-B2
Application number	US-201615756423-A
Country	US
Kind code	B2
Filing date	Sep 1, 2016
Priority date	Sep 1, 2015
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

An instrumented tool for surface finishing of a work-piece, the instrumented tool comprising: a tool configured to be spun and brought into contact with the work-piece while spinning; a spindle configured to provide a spinning torque to spin the tool; a flexible coupler provided between the spindle and the tool to transmit only spinning torque of the spindle to the tool; a rigid connection provided between the spindle and the tool in parallel to the flexible coupler; and a multi-axis force/torque/strain/pressure sensor attached to at least the rigid connection; wherein the rigid connection and the multi-axis force/torque sensor are decoupled from spinning of the spindle and the tool, and wherein the multi-axis force/torque sensor is configured to measure at least one of: contact force and torque between the tool and the work-piece.

First claim

The invention claimed is:

1. An instrumented tool for surface finishing of a work-piece, the instrumented tool comprising:
a tool configured to be spun and brought into contact with the work-piece while spinning;
a spindle configured to provide a spinning torque to spin the tool;
a flexible coupler provided between the spindle and the tool to transmit only spinning torque of the spindle to the tool;
a rigid connection provided between the spindle and the tool in parallel to the flexible coupler; and
a multi-axis force/torque/strain/pressure sensor attached to at least the rigid connection;
wherein the rigid connection and the multi-axis force/torque/strain/pressure sensor are decoupled from spinning of the spindle and the tool, and
wherein the multi-axis force/torque/strain/pressure sensor is configured to measure at least one of: contact force and torque between the tool and the work-piece.

2. The instrumented tool of claim 1 , wherein the rigid connection comprises a first rigid bracket attached to a casing of the spindle and a second rigid bracket attached to a holder of the tool.

3. The instrumented tool of claim 2 , wherein the first rigid bracket is L-shaped and the second rigid bracket is L-shaped.

4. The instrumented tool of claim 2 , wherein the multi-axis force/torque/strain/pressure sensor connects the first rigid bracket to the second rigid bracket.

5. The instrumented tool of claim 2 , wherein the holder is connected to the tool via a set of bearings that decouple the holder from spinning of the tool.

6. The instrumented tool of claim 1 , wherein the rigid connection comprises a cylindrical structure, a first end of the cylindrical structure connected via bearings to a shaft of the spindle and a second end of the cylindrical structure connected via bearings to a shaft of the tool.

7. The instrumented tool of claim 1 , wherein the multi-axis force/torque/strain/pressure sensor comprises a hollow sensor, the hollow sensor provided between and attached to both the spindle and the rigid connection, the shaft of the spindle passing through the hollow sensor.

8. The instrumented tool of claim 7 , wherein the hollow sensor comprises a hollow load cell.

9. The instrumented tool of claim 1 , further comprising a sensor configured to sense spinning torque transmitted from the spindle to the tool.

10. The instrumented tool of claim 9 , wherein the sensor comprises two encoders provided at each of two opposite ends of the flexible coupler to measure torsion transmitted through the flexible coupler.

11. The instrumented tool of claim 1 , further comprising an encoder provided at a motor of the spindle to measure at least one of: angular position and velocity of the tool.

12. A method of determining a force F 0 and a torque T 0 between the work-piece and the tool of the instrumented tool of claim 1 , the method comprising the steps of:
(a) the multi-axis force/torque/strain/pressure sensor sensing a force F ΛX and a torque T ΛX applied by the tool to the work-piece; and
(b) solving for F 0 and T 0 using the following equation:

(

F
0

T
0

)

=

[

R
LC

TSK

0

R
LC

TSK

⁢

Δ
^

LC

R
LC

TSK

]

⁢

(

F

Λ
⁢

⁢
X

T

Λ
⁢

⁢
X

)

where vector {circumflex over (Δ)} LC and matrix TSK R LC represent displacement of origin and rotation of axes of a coordinate system of the tool with respect to a coordinate system of the multi-axis force/torque/strain/pressure sensor respectively,
and where

Δ
^

LC

=

[

Δ
⁢

⁢
x

0

Δ
⁢

⁢
z

]

Assignees

• Univ Nanyang Tech

Inventors

• Campolo Domenico
• Phan Gia-Hoang
• Hussain Asif

Classifications

• B24B27/027

  having a flexible shaft · CPC title

• B24B49/16 Primary

  taking regard of the load · CPC title

• G01L3/04

  wherein the torque-transmitting element comprises a torsionally-flexible shaft · CPC title

• G01L1/005

  by electrical means and not provided for in G01L1/06 - G01L1/22 · CPC title