Sudden jumps in Sensor fusion

edited November 2019 in Requests & Bug Reports

We're experiencing sudden jumps in the sensor fusion's quaternion output on Mbient sensors. It works as expected for 10-20-30 seconds or more, without any drift, then suddenly, in the course of a second, the sensor's output rotates sometimes 20°, sometimes 40°, sometimes 90° around the vertical axis (parallel with gravity). Then it stays like that for a while, and moves with sensor movement.
We use sensor fusion in NDoF mode, accelerometer's range is 16g, gyroscope range is 2000°/s. The movements that we test with are slower than 500°/s, just holding the sensor in hand and moving it around. The sudden jump usually happened for us when the sensor didn't move at all, but has been stationary for more than 5 seconds.

We've done successful calibration and stored the calibration data on the sensor in an execOnBoot macro.


  • We may have found the solution to this one.
    Turns out, if we do the accelerometer and magnetometer parts of the calibration process a few seconds longer after it signals high calibration accuracy, it improves the sensor fusion output and the sudden jumps don't happen anymore.

    Thanks for responding. We'll keep testing.

  • Thank for the update to let everyone else in the community know!

  • edited December 2019

    I'm experiencing the same issue. The data (Pitch angle in this case) suddenly jumps for about 50 degrees and returns back after a few samples.
    I have encountered this on other MotionR sensor but seems to be random overall. During some sessions a sensor exhibits this behavior but other times it doesn't. I'm using the iOS app by the way.

  • Hi ,
    I am also facing the same problem of sudden jumps in quaternion values while using sensor fusion (NDOF). Kindly elaborate on the steps taken to overcome the above problem.
    I am first calibrating the sensor using the python script given with sdk. Thereafter, I am using sensor fusion python script to acquire the quaternion data.
    Kindly elaborate the steps you have taken to overcome the problem. I am just stuck because of it.
    It would be really helpful!!!

  • You should get jumps in euler streams (from gimbal lock) but not from quaternion stream.

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