Bosch Sensortec Community

    Showing results for 
    Search instead for 
    Did you mean: 

    BHI160B Gravity output takes a long time to settle

    BHI160B Gravity output takes a long time to settle


    Hi all,

    We are currently using the BHI160B Gravity vector to calauclate pitch and roll of a platform. We electronically control the vertical height of the lef and right sides of the platform, and the front of the platform is set in space, unable to move. So, if we lift both sides up/down then the pitch changes. If we move one side and not the other, then the roll changes (and also  a bit of pitch too, but you get the idea I'm trying to make).

    Experimentally, we move fairly slow, around one degree per second. We also only move around 2-3 degrees in total. The issue we have found is that once we have started moving, the calculated pitch and roll substantially lags the actual pitch and roll. This seems to be because the output of the accelerometer and gyroscope sensor fusion (the gravity vector) is heavily damped... after a movement, it can take up to 10 seconds for the gravity vector to approximate the unchanging acceleration vector! This typically results in extreme over/under shoot in our application.

    I guess my questions are

    1. Any ideas on how to undamp the gravity vector so we can achieve a faster settling time during movement (on the scale of 50ms)? We're okay with a little bit of ringing in the estimation, but we're not able to work with the current settlign time. 
    2. Any ideas on what else might be causing the issue? 
    3. My understanding is that the gravity vector should work perfectly fine while moving, and that's the whole point, right? It filters out movement acceleration to provide just gravity acceleration via sensor fusion with the gyro?
    5 REPLIES 5

    Community Moderator
    Community Moderator

    Hello brettCM,

    We recommend using BHI260. You could test whether it meets your requirement.