Torque measurement using millimeter-wave metamaterial

Patent metadata

Field	Value
Publication number	US-11287338-B2
Application number	US-201916591806-A
Country	US
Kind code	B2
Filing date	Oct 3, 2019
Priority date	Oct 3, 2019
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A method of determining a torque applied to a rotatable shaft is provided. The method includes transmitting a first electro-magnetic transmit signal towards a first mutually coupled structure mechanically coupled to the rotatable shaft, converting, by the first mutually coupled multitrack structure, the first electro-magnetic transmit signal into a first electro-magnetic receive signal; receiving the first electro-magnetic receive signal; evaluating the received first electro-magnetic receive signal; and determining the torque applied to the rotatable shaft based on the evaluated first electro-magnetic receive signal.

First claim

What is claimed is:

1. A torque measurement system, comprising:
a first rotatable carrier structure mechanically coupled to a rotational shaft and configured to rotate about a rotational axis in a rotation direction;
a second rotatable carrier structure mechanically coupled to the rotational shaft and configured to rotate about the rotational axis in the rotation direction, wherein the second rotatable carrier structure is spaced apart from the first rotatable carrier structure;
a first metamaterial track coupled to the first rotatable carrier structure, wherein the first metamaterial track is arranged outside of the rotational axis, and wherein the first metamaterial track comprises a first array of elementary structures;
a second metamaterial track coupled to the second rotatable carrier structure, wherein the second metamaterial track is arranged outside of the rotational axis, and wherein the second metamaterial track comprises a second array of elementary structures,
wherein the first metamaterial track and the second metamaterial track are mutually coupled to each other by a first torque dependent coupling, thereby forming a first mutually coupled structure;
at least one transmitter configured to transmit a first electro-magnetic transmit signal towards the first mutually coupled structure, wherein the first mutually coupled structure is arranged to convert the first electro-magnetic transmit signal into a first electro-magnetic receive signal based on a torque applied to the rotational shaft; and
at least one receiver configured to receive the first electro-magnetic receive signal.

2. The torque measurement system of claim 1 , wherein the first metamaterial track and the second metamaterial track are spaced apart by a first predetermined distance.

3. The torque measurement system of claim 2 , wherein:
the first rotatable carrier structure mechanically is coupled to the rotational shaft at a first point of attachment and the second rotatable carrier structure mechanically is coupled to the rotational shaft at a second point of attachment, and
the first point of attachment and the second point of attachment are spaced apart by a second predetermined distance that is greater than the first predetermined distance.

4. The torque measurement system of claim 2 , further comprising:
a flexible spacer interposed between the first rotatable carrier structure and the second rotatable carrier structure, wherein the flexible spacer defines the first predetermined distance.

5. The torque measurement system of claim 1 , wherein the first torque dependent coupling affects an mm-wave property of the first mutually coupled structure such that the mm-wave property changes based on the torque applied to the rotational shaft.

6. The torque measurement system of claim 5 , wherein the first torque dependent coupling includes at least one of capacitive near field coupling, inductive near field coupling, waveguide coupling, or far field coupling.

7. The torque measurement system of claim 5 , wherein:
the first mutually coupled structure is configured to modify the first electro-magnetic transmit signal based on the first torque dependent coupling, thereby producing the first electro-magnetic receive signal having a first property unique to the torque applied to the rotational shaft, and
the torque measurement system further comprises at least one processor configured to determine the torque applied to the rotational shaft based on the received first electro-magnetic receive signal,
wherein the at least one processor is configured to evaluate the first property of the received first electro-magnetic receive signal, and determine the torque applied to the rotational shaft based on the evaluated first property.

8. The torque measurement system of claim 1 , wherein, in response to the torque applied to the rotational shaft, the first metamaterial track and the second metamaterial track are configured to rotate about the rotational axis by differing amounts causing a torque dependent shift in angular position between the first metamaterial track and the second metamaterial track and resulting in a torque dependent change to the first torque dependent coupling.

9. The torque measurement system of claim 1 , wherein:
the first metamaterial track is arranged at least partially around the rotational axis and a coupling effect between elementary structures of the first array of elementary structures is constant around a perimeter of the first metamaterial track, and
the second metamaterial track is arranged at least partially around the rotational axis and a coupling effect between elementary structures of the second array of elementary structures is constant around a perimeter of the second metamaterial track.

10. The torque measurement system of claim 1 , wherein:
the first mutually coupled structure is configured to convert the first electro-magnetic transmit signal into the first receive signal based on the first torque dependent coupling by at least one of partial reflection or partial absorption, and
the first electro-magnetic receive signal is either a partially-reflected signal of the first transmit signal that is reflected by the first mutually coupled structure or a partially-transmitted signal of the first transmit signal that passes through the first mutually coupled structure.

11. The torque measurement system of claim 1 , further comprising:
at least one processor configured to determine the torque applied to the rotational shaft based on the received first electro-magnetic receive signal.

12. The torque measurement system of claim 11 , wherein:
the receiver is configured to demodulate the received first electro-magnetic receive signal to generate a demodulated signal, and
the at least one processor is configured to evaluate a property of the received first electro-magnetic receive signal using at least one of phase analysis, amplitude analysis, or spectral analysis, and determine the torque applied to the rotatable shaft based on the evaluated property.

13. The torque measurement system of claim 1 , further comprising:
a third metamaterial track coupled to the first rotatable carrier structure, wherein the third metamaterial track is arranged around the rotational axis, and wherein the third metamaterial track comprises a third array of elementary structures,
wherein the at least one transmitter is configured to transmit a second electro-magnetic transmit signal at the third metamaterial track, wherein the third metamaterial track is arranged to convert the second electro-magnetic transmit signal into a second electro-magnetic receive signal,
the at least one receiver is configured to receive the second electro-magnetic receive signal.

14. The torque measurement system of claim 13 , wherein:
the third metamaterial track is configured to modify the second electro-magnetic transmit signal, thereby producing the second electro-magnetic receive signal having a property unique to an angular position of the third metamaterial track at which the second electro-magnetic transmit signal is incident, and
the torque measurement system further comprises at least one processor configured to evaluate the property of the received second electro-magnetic receive signal, and determine a first rotational position of the first rotatable carrier structure based on the evaluated property.

15. The torque measurement system of claim 13 , further comprising:
at least one processor configured to determine a first position change of the first rotatable carrier structure based on the second electro-magnetic receive signal.

Assignees

• Infineon Technologies Ag

Inventors

• Hammerschmidt Dirk
• Michenthaler Christof

Classifications

• G01L3/105 Primary

  involving inductive means (G01L3/102, G01L3/104 take precedence) · CPC title

• G01L3/109

  involving measuring phase difference of two signals or pulse trains · CPC title

• G01L3/14

  wherein the torque-transmitting element is other than a torsionally-flexible shaft · CPC title