Two-mirror tracking system for free-space optical communication

Patent metadata

Field	Value
Publication number	US-11716140-B2
Application number	US-201916256406-A
Country	US
Kind code	B2
Filing date	Jan 24, 2019
Priority date	Jan 24, 2019
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

The disclosure provides a system for transmitting and receiving optical signals. The system includes a first mirror of a communication device, a first mirror actuator configured to control a pointing direction of the first mirror, a second mirror of the communication device, a second mirror actuator configured to control a pointing direction of the second mirror, and one or more processors. The one or more processors are configured to direct the second mirror actuator to move the second mirror to track a signal within a zone in an area of coverage of the communication device and meanwhile keep the first mirror stationary at a first angle. The one or more processors are also configured to direct the first mirror actuator to move the first mirror to a second angle in a direction of motion of the signal when the signal reaches an edge of the zone and meanwhile move the second mirror to a default angle.

First claim

The invention claimed is:

1. A system for transmitting and receiving optical signals, the system including:
a first mirror of a communication device;
a first mirror actuator configured to control a pointing direction of the first mirror;
a second mirror of the communication device;
a second mirror actuator configured to control a pointing direction of the second mirror; and
one or more processors operatively coupled to the first mirror actuator and the second mirror actuator, the one or more processors being configured to:
direct the second mirror actuator to move the second mirror to track a signal within a first zone of a plurality of range of motion zones in an area of coverage of the communication device,
wherein each zone is adjacent to at least one other zone of the plurality of range of motion zones, and
keep the first mirror stationary at a first angle during a first time period while using the second mirror to track the signal in the first zone;
when the signal reaches an edge of the first zone at a first time, direct the first mirror actuator to move the first mirror, during a second time period starting at the first time and ending at a second time, from the first angle to a second angle in a direction of motion of the signal as the signal moves into a second zone of the plurality of range of motion zones;
direct the second mirror actuator to move the second mirror, during the second time period, to a default angle while moving the first mirror from the first angle to the second angle; and
keep the first mirror stationary at the second angle during a third time period starting at the second time while using the second mirror to track the signal in the second zone.

2. The system of claim 1 , wherein the first mirror is kept stationary by locking the first mirror in place and turning off power to the first mirror actuator.

3. The system of claim 1 , wherein the area of each zone of the plurality of range of motion zones does not overlap with any other zone of the plurality of range of motion zones and is approximately a same percentage of a range of motion of the second mirror.

4. The system of claim 1 , wherein the area of coverage of the communication device is determined by combining a range of motion of the first mirror and a range of motion of the second mirror.

5. The system of claim 1 , wherein the one or more processors are further configured to:
when the signal reaches an edge of the second zone at a third time, direct the first mirror actuator to move the first mirror, during a fourth time period starting at the third time and ending at a fourth time, from the second angle to a third angle in a direction of motion of the signal as the signal moves into a third zone of the plurality of range of motion zones; and
keep the first mirror stationary at the third angle during a fifth time period starting at the fourth time while using the second mirror to track the signal in the third zone.

6. The system of claim 1 , wherein the second angle is a set interval from the first angle.

7. The system of claim 1 , further comprising the communication device.

8. A method for transmitting and receiving optical signals, the method including:
controlling, by one or more processors, a first mirror actuator to control a pointing direction of a first mirror of a communication device; and
controlling, by the one or more processors, a second mirror actuator to control a pointing direction of a second mirror of the communication device,
wherein the second mirror actuator moves the second mirror to track a signal within a first zone of a plurality of range of motion zones in an area of coverage of the communication device,
wherein each zone is adjacent to at least one other zone of the plurality of range of motion zones,
wherein the first mirror is kept stationary at a first angle during a first period while the second mirror is used to track the signal in the first zone, wherein, when the signal reaches an edge of the first zone at a first time, the first mirror actuator moves the first mirror, during a second time period starting at the first time and ending at a second time, from the first angle to a second angle in a direction of motion of the signal as the signal moves into a second zone of the plurality of range of motion zones,
wherein the second mirror actuator moves the second mirror, during the second time period, to a default angle while the first mirror actuator moves the first mirror from the first angle to the second angle, and
wherein first mirror is kept stationary at the second angle during a third time period starting at the second time while the second mirror is used to track the signal in the second zone.

9. The method of claim 8 , wherein the first mirror is kept stationary by locking the first mirror in place and turning off power to the first mirror actuator.

10. The method of claim 8 , wherein the area of each zone of the plurality of range of motion zones does not overlap with any other zone of the plurality of range of motion zones and is approximately a same percentage of a range of motion of the second mirror.

11. The method of claim 8 , further comprising determining, by the one or more processors, the area of coverage of the communication device by combining a range of motion of the first mirror and a range of motion of the second mirror.

12. The method of claim 8 , wherein, when the signal reaches an edge of the second zone at a third time, the first mirror actuator moves the first mirror, during a fourth time period starting at the third time and ending at a fourth time, from the second angle to a third angle in a direction of motion of the signal as the signal moves into a third zone of the plurality of range of motion zones, and
wherein the first mirror is kept stationary at the third angle during a fifth time period starting at the fourth time while the second mirror is used to track the signal in the third zone.

13. The method of claim 8 , wherein the second angle is a set interval from the first angle.

Assignees

• X Dev Llc

Inventors

• Csonka Paul
• Ulander Klaus
• Erkmen Baris Ibrahim

Classifications

• H04B10/11 Primary

  Arrangements specific to free-space transmission, i.e. transmission through air or vacuum · CPC title

• G02B7/1821

  for rotating or oscillating mirrors · CPC title

• G02B7/1827

  Motorised alignment · CPC title

• G02B26/0833

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• H04B10/1123

  Bidirectional transmission · CPC title