7/30/2019 Indoor Tracking (IMU + Tags)

1/2

1/29/13 Indoor tracking (IMU + tags)

www.stackprinter.com/export?format=HTML&service=stackoverflow&q uestion=7570202 1/2

Indoor tracking (IMU + tags)

[+2] [2] Johny 19

[2011-09-27 13:44:36]

[ android tracking accelerometer gyroscope inertia ]

[ http://stackoverflow.com /questions/757 0202/indoor-tracking-imu -tags ]

this is an other question about indoor tracking using inertial (smartphone + aceel + gyro) FirstlyI would like to say that I have read almost every post on stackoverflow talking about this subject.

And I know that to track a position We will have to integrate TWICE the accel and thatis very useless in a real life application because of all the drift errors...

But it turned out that I don't need to build a plane or whatever And i don't need to developp anapplication that have to WORK to be sold or something . I just want to realize a simple Android

App that use "theoretical" concept of an Indoor tracking-

What's the possibilities?What do we need ?

Basically my phone is resting on a desk screen facing UP at a known position (0,0) ifa push my phone to 2 or 3 meter and then i rotate it and i push it again for 2 or 3meter I the to see after how many meter it becomes to inaccurate an so use a tag turecalibrate the measurements

7/30/2019 Indoor Tracking (IMU + Tags)

2/2

1/29/13 Indoor tracking (IMU + tags)

www.stackprinter.com/export?format=HTML&service=stackoverflow&q uestion=7570202 2/2

Good luck.

EDIT : I recently found this [2] - it may be helpful to you. If there is not a lot of noise (due to v ibration),

this would work (I'm on a quadro tor UAV and it unfortunately doesn't work for me).

[1] http://opencv.willowgarage.com/wiki/

[2] http://mbed.org/users/aberk/notebook/dead-reckoning/

1

[0] [2011-11-18 23:35 :04] FarK

Y our smartphone prob ably hav e a 3-ax is gy ro , a 3-ax is magnetometer and a 3-ax is accelerometer. This

is enough for a goo d estimation of attitude. Each has its advantages and disadv antages:

The accelerometers can measured the gravity force, it give you the attitude of your phone, but in ahorizontal position, you won't can know where it's pointing. And it's very sensitive to inertial noise.

The gyroscope s are fastest and the most acc urate, but its problem it the drift.

The magnetometers don't have drift and they aren't sensitive to inertial forc es, but are too slow.

The combination of the three give you all advantages and no disadvantages. You must read the gyromeasure faster as you c an (this minimizes the drift) and then use the slow and not as acc urate measure of

magnetometer and accelerometer to c orrec t them.

I leave yo u some links that may interest you:

A Guide to using IMU: http://www.starlino .com/imu_guide.html

DCM tutorial: http://www.starlino.co m/dcm_tutorial.html

I hope I 'v e been helpful and sorry for my bad English.

-1 Th at's for a ttit ude estim ation, but the OP asked about position estim ation. - Laurent Couv idouYou need the att it ude est im ation to get the position estim at ion. Al so he ta lks about DCM algorith m which is used

for attitude estimation. - FarK2

http://www.starlino.com/dcm_tutorial.htmlhttp://www.starlino.com/imu_guide.htmlhttp://mbed.org/users/aberk/notebook/dead-reckoning/