基于弹道弯曲角速度单矢量的制导炮弹滚转角空中粗对准方法

As the interior ballistics of guided projectiles feature high rotational speed and high overload, the initial alignment of roll angle can only be achieved in air. To solve this problem, a coarse roll angle alignment method based on trajectory bending angular velocity in free flight phase is proposed. Without satellite and maneuver assistance, using the trajectory bending angular velocity induced by gravity as reference, the roll angle is obtained by single vector attitude determination. Then, the frequency domain characteristics of the projectile attitude motion measurement is analyzed to reduce the impact of the zero bias, misalignment and other errors of the low accuracy gyroscope. A FIR bandpass filter is utilized to extract desired component of the angular rate measurement at the rolling frequency point. An integration strategy under the frozen projectile system at the beginning of alignment is adopted to suppress the random noise, thereby improving the performance of the alignment. The influence of inertial gyroscope error on alignment accuracy is explored by mathematical simulation. The simulation results show that through this method, fast coarse alignment of roll angle in free flight can be realized only using low precision angular rate gyroscope, and the error is about 1̊. In the flight test, the roll angle alignment error can be controlled within 2̊.