Power management for optical position tracking devices

Patent metadata

Field	Value
Publication number	US-10554886-B2
Application number	US-201815984130-A
Country	US
Kind code	B2
Filing date	May 18, 2018
Priority date	May 18, 2018
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

Described herein are devices and techniques for managing power consumption of a position tracking device. The position tracking device may be a virtual reality (VR) controller having multiple optical sensors oriented to receive optical signals from different directions. A stationary optical emitter projects a laser line into a space and repeatedly scans the laser line through the space. For any given scan, some of the sensors may detect the laser line and some of the sensors may not detect the laser line because they are oriented away from the emitter or because of a blocking object. When an individual sensor fails to detect a laser scan, that sensor is disabled for one or more subsequent laser scans in order to reduce power consumption of the VR controller.

First claim

What is claimed is:

1. A method, comprising:
receiving, at a first optical sensor, an optical signal from a stationary emitter during a first emitter cycle;
analyzing the optical signal to determine a position coordinate relative to the stationary emitter;
determining that a second optical sensor did not receive the optical signal during the first emitter cycle; and
disabling the second optical sensor during at least a first portion of a second emitter cycle based at least in part on determining that the second optical sensor did not receive the optical signal.

2. The method of claim 1 , further comprising:
determining that a third optical sensor did not receive the optical signal during the first emitter cycle;
determining that the third optical sensor is adjacent to a fourth optical sensor that received the optical signal during the first emitter cycle; and
in response to determining that the third optical sensor is adjacent the fourth optical sensor, enabling the third optical sensor during the second emitter cycle.

3. The method of claim 1 , wherein the first emitter cycle comprises:
an omni-directional synchronization pulse; and
a laser line that sweeps through a space.

4. The method of claim 1 , wherein:
the first emitter cycle comprises a laser line that sweeps through a space; and
the laser line is encoded to indicate a current projection angle of the laser line.

5. The method of claim 1 , further comprising:
receiving information regarding expected performance; and
disabling the second optical sensor for a number of emitter cycles after the first emitter cycle, wherein the number is based at least in part on the expected performance.

6. The method of claim 1 , wherein the first optical sensor and the second optical sensor are disposed on a device, the method further comprising:
determining whether the device is moving; and
disabling the second optical sensor for a number of emitter cycles after the first emitter cycle, wherein the number is based at least in part on whether the device is moving.

7. The method of claim 1 , wherein the first optical sensor and the second optical sensor are disposed on a device, the method further comprising:
detecting a speed of the device; and
disabling the second optical sensor for a number of emitter cycles after the first emitter cycle, wherein the number is based at least in part on the speed of the device.

8. The method of claim 1 , wherein the optical signal comprises a first optical signal, the method further comprising:
determining an expected arrival time of a second optical signal associated with the second emitter cycle based at least in part on an observed arrival time of the first optical signal during the first emitter cycle;
determining a first time span within the second emitter cycle that encompasses the expected arrival time of the second optical signal; and
enabling the second optical sensor during the first time span.

9. The method of claim 8 , further comprising:
determining a second time span within the second emitter cycle that encompasses the expected arrival time of the second optical signal, the second time span being longer than the first time span;
determining that a third optical sensor did not receive the first optical signal during the first emitter cycle; and
disabling the third optical sensor during the second time span of the second emitter cycle.

10. A method, comprising
detecting, at a first optical sensor, a swept laser line during a first emitter cycle;
determining a position coordinate based at least in part on the swept laser line;
determining that a second optical sensor did not detect the swept laser line; and
based at least in part on determining that the second optical sensor did not detect the swept laser line, disabling the second optical sensor during at least a portion of a second emitter cycle.

11. The method of claim 10 , further comprising:
receiving a synchronization signal; and
determining a time difference between receiving the synchronization signal and detecting the swept laser line;
wherein determining the position coordinate is based at least in part on the time difference.

12. The method of claim 10 , wherein detecting the swept laser line comprises receiving a laser signal that is encoded to specify the position coordinate.

13. The method of claim 10 , further comprising:
identifying a first time span within the second emitter cycle based at least in part on a time at which the first optical sensor detected the swept laser line; and
enabling the second optical sensor during the first time span.

14. The method of claim 13 , further comprising:
identifying a second time span within the second emitter cycle, wherein the second time span is longer than the first time span, and wherein the second time span encompasses the first time span;
determining that a third optical sensor detected the swept laser line; and
enabling the third optical sensor during the second time span.

15. A position tracking device, comprising:
optical sensors;
one or more processors; and
one or more computer-readable media storing computer-executable instructions that, when executed, cause the one or more processors to perform acts comprising:
receiving, via a first optical sensor of the optical sensors, an optical signal from an emitter;
determining a position coordinate of the position tracking device relative to the emitter based at least in part on the optical signal;
determining that a second optical sensor of the optical sensors did not receive the optical signal; and
disabling the second optical sensor during at least a first portion of a second emitter cycle based at least in part on determining that the second optical sensor did not receive the optical signal.

16. The position tracking device of claim 15 , wherein the first emitter cycle comprises:
an omni-directional synchronization pulse; and
a laser line that sweeps through a space.

17. The position tracking device of claim 15 , wherein:
the first emitter cycle comprises a laser line that sweeps through a space; and
the laser line is encoded to indicate a current projection angle of the laser line.

18. The position tracking device of claim 15 , the acts further comprising:
receiving information regarding an expected performance; and
disabling the second optical sensor for a number of emitter cycles after the first emitter cycle, wherein the number is based at least in part on the expected performance.

19. The position tracking device of claim 15 , the acts further comprising:
determining a speed of the position tracking device; and
disabling the second optical sensor for a number of emitter cycles after the first emitter cycle, wherein the number is based at least in part on the speed of the position tracking device.

20. The position tracking device of claim 15 , further comprising an inertial measurement unit (IMU), wherein the optical signal comprises a first optical signal, and the acts further comprising:
identifying a third optical sensor of the optical sensors that did not receive a second optical signal during a third emitter cycle;
receiving, from the IMU, an indication that the position tracking device is moving; and
enabling the second optical sensor during a fourth emitter cycle in response to receiving the indication.

Assignees

• Valve Corp

Inventors

• Rydberg Rob

Classifications

• G02B27/0093

  with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking · CPC title

• G02B2027/0187

  slaved to motion of at least a part of the body of the user, e.g. head, eye · CPC title

• G02B2027/0138

  comprising image capture systems, e.g. camera · CPC title

• G02B27/017

  Head mounted · CPC title

• G01S1/703

  Details · CPC title