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.

source by Google TechTalks

android

Mourad ELGORMA

Fondateur de summarynetworks, passionné des nouvelles technologies et des métiers de Réseautique , Master en réseaux et système de télécommunications. ,j’ai affaire à Pascal, Delphi, Java, MATLAB, php …Connaissance du protocole TCP / IP, des applications Ethernet, des WLAN …Planification, installation et dépannage de problèmes de réseau informatique……Installez, configurez et dépannez les périphériques Cisco IOS. Surveillez les performances du réseau et isolez les défaillances du réseau. VLANs, protocoles de routage (RIPv2, EIGRP, OSPF.)…..Manipuler des systèmes embarqués (matériel et logiciel ex: Beaglebone Black)…Linux (Ubuntu, kali, serveur Mandriva Fedora, …). Microsoft (Windows, Windows Server 2003). ……Paquet tracer, GNS3, VMware Workstation, Virtual Box, Filezilla (client / serveur), EasyPhp, serveur Wamp,Le système de gestion WORDPRESS………Installation des caméras de surveillance ( technologie hikvision DVR………..). ,

44 réflexions sur “Sensor Fusion on Android Devices: A Revolution in Motion Processing

  • juillet 21, 2021 à 7:32
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    youtube(google) should integrate IQ and Knowledge into thumbs-up/down. because that way when you see the ratio you'll have a better chance of correctly evaluate yourself!

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  • juillet 21, 2021 à 7:32
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    This is 5 years old video, is it still up to date in terms of what they use? 🙂 anyone knows?

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  • juillet 21, 2021 à 7:32
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    42:17 Hi im little bit dumb. How does he get 9 numbers from 3 axis points? How does the twist work to give 6 extra numbers? "Those axis twist around with the teapot…" i dont get it.

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  • juillet 21, 2021 à 7:32
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    It was incredible. This video help me a lot to approach my thesis based on staft related with acc. Thanks. GreatJob

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  • juillet 21, 2021 à 7:32
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    yet still the nexus 6p has tons of problems with its sensors. some gyro axis are not on zero when static, gravity value of the linear acceleration virtual sensor is off and there is no way to calibrate any of them…

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  • juillet 21, 2021 à 7:32
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    26:44 I doesnt get it …why is use Kalman filter, and what was about pedometer. Someone can me explain it ,please?

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  • juillet 21, 2021 à 7:32
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    38:30 "Yes, it's pronounced "Oiler". I'm not sure why."
    MAYBE BECAUSE HE WAS SWISS?? DURRR… Goddamn american dumbasses… Holy shit, that was retarded.

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  • juillet 21, 2021 à 7:32
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    Can someone explain how the pan change worked at 38:00 assuming I have got the rotationMatrix from the sensor library, how to I pan the 2D image on my mobile screen?

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  • juillet 21, 2021 à 7:32
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    Even 6 years later, it seems to be the most comprehensive talk about sensors and sensor fusion I have ever watched. Thank you!

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  • juillet 21, 2021 à 7:32
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    Hi! If you want an app capable of working with all the sensors from CC2541DK, CC2650STK, ThunderBoard React and Sense (e.g. acclrm., magnetom., gyro. etc.) you can download it from: http://www.microsoft.com/store/apps/9p054xsjjr1n – the software is able of giving new uses (movement security systems – door or luggage, magnetic security system, accelerometer mouse and wireless presenters) to all these IoT SensorTags. For more info.: http://www.blesstags.eu. Thank you so much and have fun!

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  • juillet 21, 2021 à 7:32
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    I saw this video again after three months and theres still so much to learn about this. This is so far the best resource on Motion Sensors and sensor fusion I have come across.

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  • juillet 21, 2021 à 7:32
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    Interesting to compare the real world design vs the point of view of abstract University teacher who wrote the wikipedia pages about what should be the same subject.

    How the GPS work so well in any cell phone? The real data from the satellite is not precise enough to detect that you arrive at a street in 50 feet. But try to discover how the cell phone work from any web site or youtube video..

    Nobody knows. Wikipedia just mention the expensive equipment that are mandatory in commercial airplanes. They know the cell phone in their pocket appear to match the performance of these devices. But all they can say is : thanks to Einstein, science works. The black hole in their knowledge is discretely ducted under the rug.

    This video published in August 2010 explain the difficulty of sensing linear displacement from the 6 sensors. A good engineer can fill the gaps, extrapolate what the device do starting from the noisy input sensors to the smooth animation that Google map and other similar application draw of the cell phone.

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  • juillet 21, 2021 à 7:32
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    very good video, helps me so much writing my master thesis. additionally he has so a clear pronunciation

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  • juillet 21, 2021 à 7:32
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    Good presentation, explains the things behind!

    Although now in the latest APIs there are composite sensors like
    – ROTATION VECTOR (accelerometer + magnetometer + gyroscope)
    – GAME ROTATION VECTOR (accelerometer + gyroscope)
    – GEOMAGNETIC ROTATION VECTOR (accelerometer + magnetometer)
    which are using SensorFusion technique by default and their output can be used in methods like "GetRotationMatrixFromVector", "GetQuaternionFromVector".

    See also:
    https://source.android.com/devices/sensors/sensor-types#attitude_composite_sensors

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  • juillet 21, 2021 à 7:32
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    Even 8 years later, it seems to be the most comprehensive talk about sensors and sensor fusion I have ever watched. Thank you!

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  • juillet 21, 2021 à 7:32
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    Regarding the gravity signal, he says "it's actually mostly gyroscope data, but with the accelerometer used to correct drift" (at 17:59). I can't find any information on how this is done.

    The W3C Motion Sensors Explainer hints at the same thing: "On most sensor hubs, gravity is isolated from the accelerometer using the gyroscope" (https://www.w3.org/TR/motion-sensors/#relative-orientation), but also lacks any detail.

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  • juillet 21, 2021 à 7:32
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    Interesting how Anglophones call a gyrometer a "giroscope". A scope is normally something you look into and/or aim with. Microscope, telescope, periscope, endoscope, borescope… Meter means "measure" as in thermometer, dynamometer, chronometer, accelerometer, magnetometer and yes, gyrometer that measures angular velocity aka the rate of angular change, from which one can compute the rotational speed. A small mystery of science and technology 🙂 Maybe there was a gyro-stabilized scope someday, probably invented by Leonaro da Vinci? Modern technologies start to correct that discrepancy: https://docs.microsoft.com/en-us/uwp/api/windows.devices.sensors.gyrometer?view=winrt-18362

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  • juillet 21, 2021 à 7:32
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    how accurate is the video these days? did the sensor accuracy develop and it works better today?

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  • juillet 21, 2021 à 7:32
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    "we ripped out the headphone jack"

    This was all your fault. Apple watched this video and this is how it all started.

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