Estimation of Full Strap-down Rotating Bomb Guidance Information Based on Unscented Kalman Filter

基于无迹卡尔曼的全捷联旋转弹导引信息估计

¹ System Engineering Institute of Sichuan Aerospace, Chengdu 610100, China
² The Third Academy of China Aerospace Science&Industry Corporation, Beijing 100074, China

Received: 6 January 2019

Abstract

In this paper, the full strap-down seeker of rotating bomb is taken as the research object, and the method of extracting the LOS (line-of-sight) angle and angular rate of the full strap-down seeker of the rotating bomb is studied. The structure of the full strap-down seeker is quite different from that of the conventional rate gyro seeker. The measurement system of full strap-down seeker is fixed to the missile, the seeker can only obtain the measurement information in the projectile coordinate system, and the measurement information is coupled with the body posture information, so it cannot be directly used for the control guidance of the rotating projectile. First, based on the conversion relationship between coordinate systems, the mathematical model of the inertial LOS angle of the rotating bomb is established, and the mathematical model of the extraction of the inertial LOS angle and angular rate of the rotating bomb is further established. Then, the Kalman filter is designed by using the unscented Kalman filter method (UKF), and the extracted LOS angle containing noise information is filtered. Finally, the mathematical simulation is carried out to verify the validity of the mathematical model of LOS angle and angular rate extraction. Compared with the Extended Kalman filter method (EKF), the UKF has a higher accuracy for estimating the navigation information of the full strap-down rotating projectile.

摘要

以旋转弹的全捷联导引头为研究对象，重点研究了旋转弹的全捷联导引头视线角及视线角速率估计方法。全捷联导引头的结构和传统速率陀螺导引头有较大差别，其测量系统与弹体固联，导引头只能获得弹体坐标系下的测量信息，并且测量信息中耦合有弹体姿态信息，无法直接用于旋转弹的控制制导。根据坐标系之间的转换关系建立了旋转弹惯性视线角的数学模型和视线角解耦模型，从而进一步确立旋转弹惯性视线角估计的数学模型。选用无迹卡尔曼滤波方法（UKF），设计出卡尔曼滤波器，对估计到的含有噪声信息的视线角进行滤波；最后进行数学仿真，验证了视线角估计数学模型的有效性，与扩展卡尔曼滤波方法（EKF）和容积卡尔曼滤波方法（CKF）相比，UKF对于全捷联旋转弹的导引信息估计有更高的精度。