A reliable adaptive estimation method for the installation error of optical angular encoder in outfield tests

Outfield tests are essential for inertial measurement sensors while the laboratory environments are different from the practical application conditions. Considered the difficulties in applying reference sensors in outfield, the motions and deformation will bring an unknown installation error to the optical angular encoders in the turntable. The external disturbances from vibrations and surges will also negatively impact the tests. To maintain accurate tests results, we develop a complementary filter with a disturbance model to estimate the installation error. An adaptive strategy is designed to compensate for unmodeled errors. Moreover, an outlier correction strategy based on the Bayesian theorem is applied to enhance the reliability of the measurements. Finally, field tests are conducted on a verification platform in outfield conditions and a high-accuracy turntable is employed in this platform. Testing results show the method can furtherly reduce the root mean square errors of the compensated rotation error by 14% compared with previous method.