FAQ: ADIS16480 Accelerometer Doesn't Reflect Gravity-Referenced Orientation

Document created by NevadaMark Employee on Nov 7, 2012Last modified by NevadaMark Employee on Nov 7, 2012
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When I use the ADIS16480, the accelerometers do not reflect the orientation with respect to gravity. They seem to respond to dynamic motion, but always settle back to a state where the x-axis and y-axis are equal to ~0g and the z-axis is equal to ~1g for their outputs, regardless of its orientation.  How can I get the accelerometers to reflect the ADIS16480's orientation, with respect to gravity?



You are observing the expected accelerometer response, when using the Local Navigation Frame mode in the ADIS16480. In order to configure the ADIS16480to use the body frame, set EKF_CNFG[3] = 1.  Using the Body Frame selection (instead of the Local Navigation Frame) will result in the accelerometers tracking the ADIS16480orientation, with respect to gravity. Check out this video for a demonstration of the difference between the Local Navigation and Body Frame settings, along with instructions on how to use the IMU Evaluation software (with the EVAL-ADIS) to make these changes.



The products used in this demonstration are:



IMU Evaluation software


For more information on the Kalman filter configuration options in the ADIS16480, check out the "Extended Kalman Filter" section of the ADIS16480 datasheet.

For more information on using the EVAL-ADIS to evaluate the ADIS16480AMLZ, check out the ADIS1648x User Guide Wiki.


I hope that helps!