Sensor for determining an angle of rotation

Patent metadata

Field	Value
Publication number	US-10845217-B2
Application number	US-201615776676-A
Country	US
Kind code	B2
Filing date	Nov 17, 2016
Priority date	Nov 17, 2015
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

Sensor for determining a rotation angle (θ) about a rotation axis. The sensor includes a rotary element mounted in a base element so as to be rotatable about the rotation axis. The rotary element is made from a first material having a first refractive index n1 and is constructed from several layers. At least one light generating device is fixedly arranged relative to the base element. At least one light detection device is fixedly arranged relative to the base element and configured to detect a light signal. At least one refractive structure is arranged in each layer and has a second refractive index n2, wherein n2≠n1. The at least one beam path extends at least in a first rotation angle range through the at least one refractive structure in order to be able to assign a specific rotation angle (θ) to the light signal detected by the at least one light detection device at least in the first rotation angle range.

First claim

The invention claimed is:

1. A sensor for determining a rotation angle (θ) about a rotation axis, the sensor comprising:
a rotary element mounted in a base element so as to be rotatable about the rotation axis;
said rotary element being made from a first material having a first refractive index n1 and, as viewed along the rotation axis, is constructed from several layers;
at least one light generating device fixedly arranged relative to the base element;
at least one light detection device fixedly arranged relative to the base element and configured to detect a light signal emitted by the at least one light generating device and that passes through the rotary element along at least one beam path;
at least one refractive structure arranged in each layer of the several layers of the rotary element and having a second refractive index n2,
wherein n2≠n1, and
wherein the at least one beam path extends at least in a first rotation angle range through the at least one refractive structure in order to be able to assign a specific rotation angle (θ) to the light signal detected by the at least one light detection device at least in the first rotation angle range.

2. The sensor of claim 1 , wherein n2<n1.

3. The sensor of claim 1 , wherein the at least one light detection device is configured to determine a light intensity.

4. The sensor of claim 1 , further comprising at least one reference light detection device configured to detect light emitted by the at least one light generating device before this light impinges on the at least one refractive structure.

5. The sensor of claim 1 , further comprising at least one reference light detection device configured to detect light emitted by the at least one light generating device before this light impinges on the rotary element.

6. The sensor of claim 1 , wherein the at least one light generating device and the at least one light detection device are arranged opposite to each other, wherein the rotation axis is arranged between the at least one light generating device and the at least one light detection device.

7. The sensor of claim 1 , wherein the at least one refractive structure is one of:
formed by a recess in the first material; and
etched into the first material.

8. The sensor of claim 1 , wherein the respective at least one refractive structure in the several layers are arranged such that respective beam paths extend in different rotation angle ranges through the respective refractive structures.

9. The sensor of claim 1 , wherein the respective at least one refractive structure in the several layers are arranged such that respective beam paths extend in different rotation angle ranges through the respective refractive structures and that overlap in sections.

10. The sensor of claim 1 , wherein the least one light generating device is configured to generate light for one of:
a plurality of the several layers; or
all of the several layers.

11. The sensor of claim 1 , wherein the at least one light detection device is configured to detect light for one of:
a plurality of the several layers; or
all of the several layers.

12. The sensor of claim 1 , wherein the rotary element comprises a first part and a second part joined to the first part, wherein the first part has a first section of the at least one refractive structure and the second part has a second section of the at least one refractive structure, and that the first section and the second section are connected so as to form the at least one refractive structure.

13. The sensor of claim 1 , wherein one of:
the least one light generating device comprises a plurality of light generating devices configured to emit light having different wavelengths;
the least one light detecting device comprises a plurality of light detecting devices configured to detect light having different wavelengths; or
the at least one light detection device is configured to detect wavelength-dispersive light.

14. The sensor of claim 1 , wherein the first material is one of:
a Si material; or
a glass material.

15. The sensor of claim 1 , wherein the at least one light generating device is at least one laser diode.

16. The sensor of claim 1 , wherein the at least one light detection device is at least one photodiode.

17. The sensor of claim 1 , further comprising at least one reference light detection device that comprises at least one photodiode.

18. The sensor of claim 1 , wherein the at least one refractive structure extends along one of:
a line in a plane normal to the rotation axis; and
a zero-curvature line in a plane normal to the rotation axis.

19. The sensor of claim 18 , wherein one of:
the line has such a curvature that at least in the first rotation angle range a certain transfer function is provided between a light signal detectable by the at least one light detection device and the rotation angle (θ); or
the line has such a curvature that at least in the first rotation angle range a linear transfer function is provided between a light signal detectable by the at least one light detection device and the rotation angle (θ).

20. A device comprising:
at least one sensor according to claim 1 ; and
a memory configured to store, at least for the first rotation angle range, a transfer function generated by the at least one refractive structure between the light signal detectable by the at least one light detection device and the rotation angle (θ).

21. A satellite comprising:
a satellite engine; and
a sensor according to claim 1 .

Assignees

• Univ Wien Tech

Inventors

• Dabsch Alexander
• Keplinger Franz
• Kainz Andreas

Classifications

• G01B21/22 Primary

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• G01B11/26

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• G01D5/34 Primary

  the beams of light being detected by photocells · CPC title

• G01D5/30

  the beams of light being detected by photocells · CPC title

• G01D5/32

  with attenuation or whole or partial obturation of beams of light (G01D5/40 takes precedence {; mechanical adjustment G01D5/264}) · CPC title