Sensor Fusion on Android Devices: A Revolution in Motion Processing

Google Tech Talk
August 2, 2010

ABSTRACT

Presented by David Sachs.

Gyroscopes, accelerometers, and compasses are increasingly prevalent in mainstream consumer electronics. Applications of these sensors include user interface, augmented reality, gaming, image stabilization, and navigation. This talk will demonstrate how all three sensor types work separately and in conjunction on a modified Android handset running a modified sensor API, then explain how algorithms are used to enable a multitude of applications.

Application developers who wish to make sense of rotational motion must master Euler angles, rotation matrices, and quaternions. Under the hood, sensor fusion algorithms must be used in order to create responsive, accurate, and low noise descriptions of motion. Reducing sensing errors involves compensating for temperature changes, magnetic disturbances, and sharp accelerations. Some of these algorithms must run at a very high rate and with very precise timing, which makes them difficult to implement within low-power real-time operating systems. Within Android specifically, this involves modifying the sensor manager, introducing new APIs, and partitioning motion processing tasks.

David Sachs began developing motion processing systems as a graduate student at the MIT Media Lab. His research there led him to InvenSense, where he continues this work with MEMS inertial sensors used in products such as the Nintendo Wii Motion Plus. David's designs incorporate gyroscopes, accelerometers, and compasses in various combinations and contexts including handset user interfaces, image stabilizers, navigation systems, game controllers, novel Braille displays, and musical instruments.

Category:

Science & Technology

Tags:

• google
• tech
• talk
• android
• sensor
• games

[Klem98]

Hi , where can i find an api to use this sensor fusion algorithm ?

[invensense1]

Edit: In the slide on "double integration", the total time of those data sets are actually 10 seconds, not 1 second. --- David Sachs

[SingletonJare4367]

BEST PROMO amzn.to\ye8jrF

Car Video

Fusion Component

Reactor speakers take the sweet sound handling capabilities of Encounter to the next level. Combining quality close-tolerance polypropylene cones with silk-dome tweeters to produce better sound definition.Component Speakers feature 3-way attenuation sensitivity to control the level of tweeter output at -3dB, 0 or +3dB and small ...

For more details please copy the Amazon link below in your browser:

amzn.to\ye8jrF

[kylemichaelbecker]

@ the question about a dynamic x and y reading, with a static z value, my first guess would be that x and y would reflect lat, long; wheras your altitude(z) may be fairly constant. hope this sheds light

[dnumdug]

Glad I got an simple explanation and understanding on those things... (!!).

Is this a IQ test or what?..

[tookiewiliams]

I have Samsung Galaxy S2 and I'm experiencing with an issue that's annoying me very much.

When i do "auto rotate" , the rotation goes after 4-5 seconds.

I've done the calibrations and all that stuffs that you will find on google or forums.

Also, i've checked secret code *#0*# , and at Accelerometer Sensor i get:

ACC Raw Data - X: changing numbers, y: changing numbers, z: 1024 ( z is not changing like X and Y)

In this case, is my Accelerometer Sensor broke Physicaly or what?! ?!

[nunojpg]

@novellterminator It's all about the drift over time you need. Airplanes and submarines can have less drift in one hour than the phone sensors in 10 seconds. If you are looking to the same precision in your phone, it is still orders of magnitude of size and price away.

[Sentilon]

is anywhere the current presentation to download?

[gnychis]

great description of why position using the sensors is challenging, thank you

[nyehnyi]

the best online lecture i ever watch..thank you so much sir