Does anyone work with sensors on Android have any go around to solve this problem?
On Sep 25, 5:15 pm, LVMH <[email protected]> wrote: > Hello, > > I am trying to develop an indoor inertial navigation system on the HTC > hero with the built-in accelerometer and digital compass. > > As far as I know about hardware, the accelerometer chip is the Bosch > Sensortec's 3-axis BMA150 and the digital compass is Asahi Kasei's > AK8973 (similar to iPhone). I am not sure about the accuracy of each > sensor but the digital compass seems to function fairly well in the > iPhone. > > What I am doing is getting accelerometer samples and magnetic field > samples at the SENSOR_DELAY_FASTEST (seems to me around 10 - 20 ms per > sample) > > Then I creates a threshold of ±1 m/s^2 for every output of > accelerometer to filter out which sample is gravity (9.807f). The same > is applied for output from the digital compass (with threshold of ± 5 > microtesla). I intended to use this filter to provide the correct > gravity and geomagnetic field for the SensorManager.getRotationMatrix > to work correctly (I am not sure if this method would actual provide > better result). > > From the rotation matrix created above, I simply use getOrientation to > get the heading (north) and convert the output from the accelerometer > from the device coordination system to the Earth's coordination system > by multiplying to the rotation matrix. > > ****** My question ****** > The result I am getting is completely not usable. It seems that the > heading is very inaccurate thus making the rotation matrix > inaccurate. > Even when I applied kalman filter, the result is still far from being > usable. > I wonder if anyone has approached this problem before and if there is > some better way to do it. > > Thanks, > lvmh --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
