Apparatus and method to conserve power in a portable GNSS unit

Patent metadata

Field	Value
Publication number	US-9658338-B2
Application number	US-201213446744-A
Country	US
Kind code	B2
Filing date	Apr 13, 2012
Priority date	Apr 13, 2012
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A device is disclosed that is capable of determining its location using high-power with high accuracy, and using low-power with lower accuracy. By coordinating usage between the high power method and the low power, overall power consumption of the device can be significantly reduced without a significant reduction in accuracy. Such high accuracy may be achieved through the use of a GNSS unit, such a GPS receiver. In addition, the low-power alternative may be achieved using an accelerometer, together with software, hardware or firmware for extrapolating a speed based on the force measurements by the accelerometer. In this manner, the GPS receiver can be operated for only a fraction of overall use, primarily to provide adjustment data necessary to calibrate usage of the accelerometer.

First claim

What is claimed is:

1. A method for measuring a speed of a GNSS-enabled device, the method comprising:
receiving force measurements from a force measurement module; and
during a first operation state:
operating a GNSS receiver in a high-power state;
calculating a step length based on the force measurements received from the force measurement module and location information received from the GNSS receiver;
storing the step length in a memory module;
calculating the speed based on the location information received from the GNSS receiver;
switching from the first operation state to a second operation state when a first predetermined time period has elapsed since the GNSS-enabled device entered the first operation state; and
switching from the second operation state to the first operation state when:
a second redetermined time period has elapsed since the GNSS-enabled device entered the second operation state; and
the calculated speed has changed from a previously-calculated speed by more than a predetermined threshold.

2. The method of claim 1 , further comprising:
during the second operation state:
operating the GNSS receiver in a low-power state; and
calculating the speed based on the force measurements received from the force measurement module and the stored step length.

3. The method of claim 2 , further comprising:
during the first operation state:
detecting a first force waveform from the force measurement module; and
storing the first force waveform.

4. The method of claim 3 , further comprising:
during the second operation state:
detecting, by the force measurement module, a second force waveform; and
performing pattern matching on the second force waveform to identify steps within the second force waveform.

5. The method of claim 4 , wherein the force measurement module is configured to detect force on a plurality of force axes, and
wherein the second force waveform is detected on a first force axis of the plurality of force axes.

6. The method of claim 5 , further comprising:
during the second operation mode:
detecting, by the force measurement module, a third force waveform on a second force axis of the plurality of force axes,
wherein the speed is calculated based on the third force waveform.

7. A GNSS-enabled device, comprising:
a force measurement module configured to measure forces on the GNSS-enabled device;
a GNSS receiver; and
one or more processors and/or circuits configured to:
receive the force measurements from the force measurement module; and
during a first operation state:
operate the GNSS receiver in a high-power state;
calculate a step length based on the force measurements received from the force measurement module and location information received from the GNSS receiver;
store the step length in a memory module;
calculate the speed based on the location in formation received from the GNSS receiver;
switch from the first operation state to a second operation state when a first predetermined time period has elapse since the GNSS-enabled device entered the first operation state; and
switch from the second operation state to the first operation state when:
a second predetermined time period has elapsed since the GNSS-enabled device entered the second operation state; and
the calculated speed has changed from a previously-calculated speed by more than a predetermined threshold.

8. The GNSS-enabled device of claim 7 ,
wherein the one or more processors and/or circuits are further configured to:
during the second operation state:
operate the GNSS receiver in a low-power state; and
calculate the speed based on the force measurements received from the force measurement module and the stored step length.

9. The GNSS-enabled device claim 8 ,
wherein the one or more processors and/or circuits are further configured to:
during the first operation state:
detect a first force waveform from the force measurement module; and
store the first force waveform.

10. The GNSS-enabled device of claim 9 ,
wherein the one or more processors and/or circuits are further configured to:
during the second operation state:
detect, by the force measurement module, a second force waveform; and
perform pattern matching on the second force waveform to identify steps within the second force waveform.

11. The GNSS-enabled device of claim 10 , wherein the force measurement module is configured to detect force on a plurality of force axes, and
wherein the second force waveform is detected on a first force axis of the plurality of force axes.

12. The GNSS-enabled device of claim 11 ,
wherein the one or more processors and/or circuits are further configured to:
during the second operation mode:
detect, by the force measurement module, a third force waveform on a second force axis of the plurality of force axes,

wherein the speed is calculated based on the third force waveform.

Assignees

• Mole Stephen
• Van Diggelen Frank
• Avago Technologies General Ip

Inventors

• Mole Stephen
• Van Diggelen Frank

Classifications

• G01S19/34 Primary

  Power consumption · CPC title

• G01C22/006

  Pedometers · CPC title

• G01S19/52

  Determining velocity · CPC title

• G01S19/19 Primary

  Sporting applications · CPC title