Using the detected drift error, filtering works in the same way as described in Section 9.1. The complementary filter (9.10) is upgraded to work with quaternions. It becomes slightly more complicated to represent the interpolation in terms of . Let denote the axis-angle representation of the orientation , which is the estimated drift error (a quaternion value). Let represent the quaternion given by axis and angle . For a small value of , this can be considered as a small step ``toward'' .
The complementary filter in terms of quaternions becomes
Steven M LaValle 2016-12-31