The Guidance Information Reconstruction of Semi-strapdown Imaging Seeker Guidance System

As the semi-strapdown seeker's dynamics is seriously nonlinear, EKF (Extended Kalman Filter) for guidance information reconstruction can not meet the requirements of high accuracy guidance. This paper uses UKF (Uncented Kalman Filter) to estimate the gimbal angular rate, and at the same time, the quasi-proportional guidance information was reconstructed by combining missile attitude rate coming from IMU with the target position information coming from seeker's imaging plane. The paper finally makes a three-dimentional practical simulation of the missile based on UKF, and compares the gimbal angular rate estimation accuracy of EKF with that of UKF. Simulation results shows that the reconstructuion accuracy of the guidacne information via UKF is better, which can guide the missile to precisely attack the target.