Research on guidance information extraction technology of strap-down seeker based on adaptive cubature Kalman filter

In comparison to the traditional platform seeker, strap-down seeker, which is firmly connected with rocket-propelled vehicle, has a lot of strength in a smaller size, a simpler structure, and a lower cost. However, because it is fixed on the rocket-propelled vehicle, inertial line-of-sight(LOS) angular velocity demanded by guidance system could not be directly obtained during the rocket-propelled vehicle flight. In this paper, according to the coordinate transformation relationship, the inertial LOS angular velocity decoupling model is established. Aiming at measurement error characteristics of a seeker, a guidance information extraction algorithm which is on basis of the adaptive cubature Kalman filter is studied, and the digital simulation experiment is carried out in combination with the engineering practice. The simulation data demonstrate that the suggested algorithm has a significant effect on improving the filtering estimation stability and accuracy of guidance information extraction and guaranteeing the accuracy of rocket-propelled vehicle hits.