Conservation of battery life in GPS accessing portable devices

Patent metadata

Field	Value
Publication number	US-10142790-B2
Application number	US-201214363824-A
Country	US
Kind code	B2
Filing date	Dec 19, 2012
Priority date	Dec 20, 2011
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A method of controlling a device that includes a receiver and a movement sensor includes (a) deactivating the receiver; (b) while the receiver is deactivated, analyzing measurements from the movement sensor to determine a measure of the distance the device has moved from a first location; and (c) in the event that it is determined from the measurements from the movement sensor that the device has moved from the first location by more than a threshold distance, activating the receiver and using the receiver to obtain a second measurement of the location of the device.

First claim

The invention claimed is:

1. A method of controlling a device that comprises a satellite positioning system receiver and a movement sensor, the method comprising:
(a) deactivating the receiver;
(b) while the receiver is deactivated,
periodically sampling an accelerometer at a predetermined sampling rate;
(c) determining a magnitude of the acceleration at each sampling point, wherein the magnitude M of acceleration is defined by M=(a x 2 +a y 2 +a z 2 ) 1/2 , where a x , a y , and a z is the acceleration along each of three orthogonal directions;
(d) determining a power of the acceleration at each sampling point wherein the power P is defined by: P=(M−g)2, where g is acceleration due to gravity; and
(e) in response to the power of the acceleration exceeding a preselected threshold, activating the receiver to receive signals from the satellite positioning system indicative of an updated current location of the device.

2. The method as claimed in claim 1 , wherein, after obtaining the satellite positioning system measurement of the location of the device in step (e), the method comprises:
(f) repeating steps (a), (b), (c), (d), and (e).

3. The method as claimed in claim 2 , wherein step (e) further comprises:
based on a plurality of the satellite positioning system measurements by the receiver, determining a speed or velocity of the device, and
adapting the threshold distance based on the determined speed or velocity of the device.

4. A non-transitory computer-readable medium carrying computer code configured to control a device that comprises a satellite positioning system receiver and a movement sensor, where executing the computer code with a computer or processor causes the computer or processor to:
(a) deactivate the receiver;
(b) while the receiver is deactivated, periodically sample an accelerometer at a predetermined sampling rate;
(c) determine a magnitude of the acceleration at each sampling point, wherein the magnitude M of acceleration is defined by M=(a x 2 +a y 2 +a z 2 ) 1/2 , where a x , a y , and a z is the acceleration along each of three orthogonal directions;
(d) determine a power of the acceleration at each sampling point wherein the power P is defined by: P=(M−g)2, where g is acceleration due to gravity; and
(e) in response to the power of the acceleration exceeding a preselected threshold, activate the receiver to receive signals from the satellite positioning system indicative of an updated current location of the device.

5. The non-transitory computer-readable medium as claimed in claim 4 , wherein, after obtaining the satellite positioning system measurement of the location of the device in (e), the executing computer code further causes the computer or processor to repeat (a), (b), (c), (d), and (e).

6. The non-transitory computer-readable medium as claimed in claim 4 , wherein the executing computer code further causes the computer or processor to:
determine a speed or velocity of the device based on a plurality of the satellite positioning system measurements by the receiver; and
adapt the threshold distance based on the determined speed or velocity of the device.

7. A device comprising:
a receiver configured to receive signals from a satellite positioning system indicative of current location of the device;
an accelerometer configured to measure acceleration of the device; and
a processor configured to:
(i) after receiving the signals from the satellite positioning system indicative of the current location, deactivate the receiver,
(ii) after deactivating the receiver, periodically sample the accelerometer at each of a plurality of sampling points,
(iii) determine a magnitude of the acceleration at each sampling point, wherein the magnitude M of acceleration is defined by M=(a x 2 +a y 2 +a z 2 ) 1/2 , where a x , a y , and a z is the acceleration along each of three orthogonal directions, and
(iv) determine a power of the acceleration at each sampling point wherein the power P is defined by: P=(M−g) 2 , where g is acceleration due to gravity, and
(v) in response to the power of the acceleration exceeding a threshold, activate the receiver to receive signals from the satellite positioning system indicative of an updated current location of the device.

8. The device as claimed in claim 7 , wherein the processor is configured to deactivate the receiver and repeat (ii)-(v) after obtaining the updated current location of the device in (v).

9. The device as claimed in claim 8 , wherein the processor is configured to calculate a measurement of speed or velocity of the device based on the updated current locations and to adapt the threshold distance based on the speed or velocity of the device.

Assignees

• Koninklijke Philips Nv

Inventors

• Pijl Marten Jeroen
• Fulton Paul Michael
• Baldus Heribert

Classifications

• G01S19/34 Primary

  Power consumption · CPC title

• G01S19/49

  whereby the further system is an inertial position system, e.g. loosely-coupled · CPC title

• A61B5/1118

  Determining activity level · CPC title

• H04W4/027 Primary

  using movement velocity, acceleration information · CPC title

• G01S5/019

  Energy consumption · CPC title