基于动力学模型约束的多矢量空中对准算法

Multi-Vector In-Flight Alignment Method Based on Dynamic Model Constraints

制导炮弹的高动态飞行对精确导航与制导带来了极大挑战。针对传统的多矢量空中对准方法中投影到初始时刻导航坐标系矢量β(t)在高动态环境下易受GNSS信息失锁、噪声干扰的问题,提出了一种基于动力学模型约束的多矢量空中对准方法。通过引入质点弹道动力学模型来设计基于EKF的弹道运动估计算法,提升制导炮弹测速、定位的精度,并进而提升β(t)矢量构建的精度。在此基础上通过矢量定姿算法实现初始姿态矩阵的对准。仿真实验表明,基于EKF的弹道运动估计算法所获取的速度误差(RMSE)降低了50%,位置误差(RMSE)降低了80%。相比于直接采用GNSS信息构建β(t)矢量,所提出的矢量构建方案结合Request矢量定姿算法可以快速实现初始时刻姿态的对准,收敛后的失准角误差(RMSE)均小于1°,满足空中粗对准的需求。

High dynamic flight of guided projectile brings huge challenges to the precise navigation and guidance.Aiming at the problem that theβ(t)in traditional multi-vector in-flight alignment method is vulnerable to GNSS unlock and noise interference in high dynamic environment,an in-flight alignment method based on dynamic model constraints is proposed.According to the projectile particle trajecto-ry dynamic model,the flight estimation algorithm based on EKF of high-spin projectile is designed,which can improve the accuracy of speed and position.The accuracy ofβ(t)vector is also improved.On this basis,the optimal estimation of the initial attitude matrix is a-chieved.Simulation experiment indicates that,through the flight estimation algorithm based on EKF of high-spin projectile,speed error is reduced by 50%(RMSE),position error is reduced by 80%(RMSE).Meanwhile,compared with the traditionalβ(t)vector construc-ted by GNSS,the in-flight coarse alignment can be achieved by the method proposed combined with the Request method,and the mis-alignment angle is less than 1 degree after convergence.