| Title |
Rotation Angle Estimation Method for Intelligence Guided Ammunition |
| Authors |
신승제(Seung-Je Shin) ; 김경훈(Gyeong-Hun Kim) ; 김환우(Whan-Woo Kim) |
| DOI |
https://doi.org/10.5573/ieie.2019.56.3.113 |
| Keywords |
Ammunition ; Guidance ; Navigation ; Control ; Rotation angle |
| Abstract |
Unlike conventional guided missiles, the intelligence gun-guided ammunition cannot set the initial position because of initial conditions of an extremity that is subject to a strong physical shock at the beginning of launch. Therefore the GPS and INS installed inside the intelligence guided ammunition are launched without power applied. The current state of the ammunition is estimated by the navigation initialization during the flight. After that, the ammunition has undergo guided control and finally the target striking accuracy can be improved. However, it is very difficult to estimate the rotation angle of the ammunition because of the 20∼30 rotations per second caused by the rifling inside the gun bore due to the characteristics of cannon launch ammunition. In the case of the M982(excalibur), an intelligence guided ammunition developed in the U.S. the rotation angle is estimated using the signal intensity of GPS and rotation rate. This method has a problem in that the roll angle estimation accuracy is significantly lowered unless the rotation rate is maintained constant for a certain period of time. In this paper, we propose a method to estimate rotation angle by comparing the acceleration data of INS after differential/rotation conversion of GPS measurements or by comparing the velocity data of GPS after integration/rotation conversion of INS measurements mounted on intelligent guided ammunition. The proposed algorithm was verified by simulation data obtained form the performance analysis program of ammunition and once again verified using telemetry data obtained from actual cannon launch test. |