Roll angle estimation of guided gun-launched projectile using MEMS angular rate gyro and magnetometer

The previous method to estimate roll angle of guided gun-launched projectile can be completely invalid in case of GPS is disabled in battlefield. To solve that problem, this paper proposes roll angle estimation used MEMS angular rate gyro and magnetometer. Comparing to the previous method with GPS, the addition of magnetometer outputs increases the measurement accuracy, but increases the dimension and nonlinearity of the measurement model. Therefore the Extended Kalman Filter is introduced. Through trajectory simulation, this study indicates that the absolute roll estimation error is less than 7 degrees after 3 seconds in whole flight trajectory, which is completely met the guided system requirement.