Attack-angle detection method based on cascaded coordinate systems

The attack angle of a guided projectile can describe the projectile's flight attitude, so it is one of the most important testing parameters during exterior ballistic experiments. In view that the guided projectile in flight is difficult to directly detect the attack angle, a new method for attack-angle estimation is proposed based on a coordinate cascade. According to the navigation parameters obtained by MINS/GNSS, the detection model for the attack angle is established, and then the estimation of the attack angle is realized by the coordinate cascade. The simulation is made based on the trajectory data of a precision guided projectile, which show that the estimation error of the attack angle is within 0.7°. The error analysis indicates that the high accuracy of the attitude estimation and the outputs by the sensors from MINS/GNSS are helpful to improve the estimation accuracy of the attack angle. The proposed method is effective to realize the detection of the attack angle for the guided projectile without any additional equipment, thus it provides a new idea for the practical detection of the attack angle. © 2016, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.