Orientation Error Modeling and Compensation Technology for Bioinspired Polarization Compass

The tilt will inevitably occur due to the carrier motion when the bioinspired polarization compass is attached to the mobile carrier (such as a drone), which brings about the zenith position in AoP images collected by the polarization imaging system to be changed. The error of fitting the solar meridian causes the AoP calculated error, decreasing the orientation accuracy for the bioinspired polarized compass dramatically. In addition, we have found in a large number of dynamic experiments that the coupling between the solar meridian and the carrier body axis angle (A-SMBA) and the inclination angle also produces very significant orientation errors. Therefore, this chapter first comprehensively analyzes the influence of the changed attitude angles by the polarization compass (including A-SMBA, pitch angle and roll angle) on the heading error. Next, the Gated Recurrent Unit (GRU) neural network is introduced to model and compensate for the orientation error caused by the changed attitude angles by the polarization compass so as to improve the orientation accuracy during the carrier actual motion.