Rotation matrix error-decoupling methods for Risley prism closed-loop tracking

In a rotational double-prism photoelectric tracking system based on image feedback, the rotation angle of the prisms must be adjusted to correct the tracking error. This study proposes a rotation matrix error-decoupling method that removes the strong coupling between the tracking errors in the x and y directions and the prism rotation in the rotational double-prism tracking device. Based on the tracking error after decoupling, the rotations of the same and reverse directions are simultaneously applied to both prisms to achieve closed-loop tracking. The high precision and robustness of the method were confirmed in simulation and experimental tracking evaluations.