Line-of-Sight Rate Estimation Based on UKF for Strapdown Seeker

Abstract

Aiming at the problem that the strapdown imaging seeker cannot measure line-of-sight (LOS) rate directly, this paper presents an effective algorithm for LOS rate estimation. To address the problem, the reference frames and angles are defined. According to the relative kinematics and attitude relationship between missile and target, the nonlinear state equations and measurement equations of LOS rate are derived, and the estimation algorithm based on unscented Kalman filter (UKF) is proposed. Considering the estimation accuracy mainly depends on body LOS (BLOS) angle accuracy and gyro accuracy, the paper is unprecedented to research how these two factors impact the LOS angle and rate accuracy by simulation. Semiphysical simulation experiment verifies the correctness and accuracy of the algorithm, and the result shows that the estimation algorithm can meet the accuracy and real-time requirements of guidance system simultaneously. Thus LOS rate estimation algorithm based on UKF provides a theoretical basis for engineering applications of strapdown imaging seeker.

Research on Extraction Method of LOS rate of Rotating Bomb Full strap-down seeker Based on Kalman Filter

“…If the inertial line of sight is used for the guidance of the missile directly, will cause the guidance precision of missile is very poor, and even could make the missile miss distance. In order to make the missile can hit the target accurately, we need to select the appropriate filtering method, filter out the noise and interference in the line of sight information, and extract useful line of sight rate information [6][7][8] .…”

Study on Parasite Effect with Strapdown Seeker in Consideration of Time Delay

“…With this approach, the stability regions of the parasite loop, involving the strapdown homing seeker, were analyzed in several studies [5][6][7][8]. As the second research direction, some efforts have also been made to devise new homing guidance laws, corresponding terminal homing guidance loops [9][10][11], and guidance filters for the strapdown seeker [12][13][14].…”

Genetic Resampling Particle Filter with Randomly Delayed Measurements and Its Application to Line-of-Sight Rate Estimation

“…5) But the performance of the EKF is unsatisfactory due to the truncations. To reduce the error caused by the truncations, an unscented Kalman filter (UKF) was proposed based on the unscented transformation method and applied to the LOS rate estimation in Sun et al 6) In addition, the cubature rule-based cubature Kalman filtering (CKF), which is more numerically stable than UKF, has also been applied to the LOS rate estimation. 7) The research results indicate that the UKF and CKF perform well in the case of Gaussian noise.…”