Thanks Scott. Yes, you are right. the Android API is calculating the orientation by using the mag and gravity(acceleration), and this is why the orientation is affected (strongly affected) by the acceleration. So just wondering if you have any idea to get the pure acceleration data without gravity involved?meaning at any time the phone only shows the net moving acceleration of the phone without G added on. Thank you!
On Oct 19, 5:46 am, Scott <[email protected]> wrote: > I'm afraid it's not mathematically possible to generate a full > attitude solution from a single vector observation (mag vector, > gravity vector, etc..). There simply isn't enough information there. > It doesn't matter if you're not pointed along the mag field, you will > still only get a partial attitude solution in the shape of a cone > centered around the mag field. This has been an issue in the aerospace > industry for a while now, and usually the problem is solved by > combining information from two or more sensors. In this case, the > Android API is probably using the mag field and what it assumes is a > gravity vector from the accelerometer (that's why the solution is > affected by external accelerations). > > If you're interested in how to generate an attitude solution from two > vector observations, you should look up the TRIAD algorithm for > attitude determination. > > Cheers, > Scott > > On Oct 12, 4:25 am, DD <[email protected]> wrote: > > > > > Hi, is it possible to calculate yaw,pitch,roll solely from x,y,z > > magnetic field values obtained from the magnetometer, for example, > > according to physics? How? Thanks a lot!- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
