AN OVERBROAD PATENT ON using acceleration sensor to turn on/off GPS receiver on a phone only when it has moved - This application seeks to patent the idea of...persistent motion tracking on a smartphone by using acceleration sensor to turn on/off GPS receiver! 10 minutes of your time can help narrow US patent applications before they become patents. Follow @askpatents on twitter to help.

QUESTION - Have you seen anything that was published before 9/30/2011 that discusses:

  • using acceleration sensors and GPS sensors together

If so, please submit evidence of prior art as an answer to this question. We welcome multiple answers from the same individual.

EXTRA CREDIT - A reference to anything that meets all of the criteria to the question above AND ALSO creates profiles of users based on where they are at rest

TITLE: Using acceleration sensor to turn on/off GPS receiver

Summary: [Translated from Legalese into English] A battery-saving technique of turning on/off the GPS receiver on a phone based on signal from acceleration sensor on phone

  • Publication Number: US20130085861 A1
  • Application Number: US 13/629,299
  • Assignee: Scott Dunlop
  • Prior Art Date: Seeking prior Art predating 9/30/2011
  • Open for Challenge at USPTO: Open through 10/1/2013
  • Link to Google Prior Art Search - "Find Prior Art"

Claim 1 requires each and every step below:

A mobile device comprising:

  1. a geopositioning receiver configured to determine a geoposition of the mobile device;

  2. an accelerometer configured to determine an acceleration rate of the mobile device; and

  3. a processor in communication with the geopositioning receiver and the accelerometer, the processor configured to:

  4. determine, using the accelerometer, whether the mobile device is in motion based on a duration of movement, an acceleration rate, and/or a velocity, and

  5. engage the geopositioning receiver upon determining that the mobile device is in motion.

In English this means:

A mobile device comprising:

  1. GPS receiver

  2. An accelerometer

  3. A program which determines whether the mobile devices is in motion and engages the GPS receiver if it is.

Good prior art would be evidence of a system that did each and every one of these steps prior to 9/30/2011

You're probably aware of ten pieces of art that meet this criteria already... separately, the applicant is claiming creating user profiles based on where the phone is at rest

"GPS Receiver and Accelerometer Flowchart from the Applicant"

What is good prior art? Please see our FAQ.

Want to help? Please vote or comment on submissions below. We welcome you to post your own request for prior art on other questionable US Patent Applications.

  • I don't think there will be any confirmation available for that but I am sure Apple did this in iPhone way before given date. Aug 27, 2013 at 10:42

6 Answers 6



This paper describes use of a method which "uses less power-intensive sensors such as an accelerometer to suppress unnecessary GPS sensing when the user is in static state."

This paper dates back to June of 2010.


This paper entitled "Energy-efficient rate-adaptive GPS-based positioning for smartphones" describes using an accelerometer as part of a blended approach to determining when to turn a GPS receiver on and off for power efficiency.

Key quote from section 3.1:

To achieve this goal, RAPS uses a collection of techniques to cleverly determine when to turn on GPS, and when not to. First, it uses a duty-cycled accelerometer to efficiently estimate user movement. RAPS detects whether the user is moving or not, and also measures the activity ratio, the fraction of time that the user is in motion between two position updates. The movement detection is used to prevent RAPS from activating GPS when the user has been stationary. The activity ratio is used to estimate the current velocity based on historical correlations between velocity and activity (see below); this lets RAPS activate GPS only if the estimated uncer- tainty in position exceeds the accuracy threshold.

The paper's publishing info's on the first page:

MobiSys’10, June 15–18, 2010, San Francisco, California, USA. Copyright 2010 ACM 978-1-60558-985-5/10/06


We applied for a very similar patent and our attorney flagged up this one: http://www.google.com/patents/US20080234935 filed in March 08 Claim 1 applies to this patent application:

"A method, comprising: detecting motion of a device in response to receipt of a signal from a first sensor disposed in said device; and changing a power state of a second sensor, also disposed in said device, in response to said detecting said motion."


This may be useful, year 2007: https://www.google.com/patents/US20070146129

A power saving device for a GPS device is to utilize acceleration of gravity sensor to continue detecting the acceleration variation of the GPS device; if an acceleration value is larger than a threshold value, a GPS signal receiver is then started; if the acceleration value is smaller than the threshold value, the GPS signal receiver is then shut. This allows the GPS device to be power saving and not need to facilitate an extra oscillation switch therein to save the production cost.


Not specifically in a phone, but the Delorme handheld GPS (released in 2010) uses the accelerometer to sense when the device is not in motion and can disable the GPS to save battery life.



GPS devices have for years (and are required by law) to turn themselves off if they are going too fast. This is to prevent them from being used on missiles.

Here is a link from 2011: http://brokensecrets.com/2011/08/20/your-gps-will-disable-itself-if-its-going-too-fast/

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