Roll Estimation of a Smart Munition Using a Magnetometer Based on an Unscented Kalman Filter
HanSung Lee, Kwang‐Jin Kim, HeeYoung Park, Chan Gook Park, Jang Gyu Lee · AIAA Guidance, Navigation, and Control Conference and Exhibit · 2008
Roll estimation is an important problem to guarantee guidance performance of a smart munition. To estimate a roll angle of the smart munition, angular velocity modulation is needed. Angular velocity modulation is derived from the fact that the roll angle is related to a pitch rate, a yaw rate and gyroscope outputs of a munition. Based on this knowledge, this paper gives the method to use an earth magnetic sensor output as a measurement. For an earth magnetic measurement, a new coordinate is defined, and the system and measurement models are derived. In the roll estimation problem, the measurement model is nonlinear. For this nonlinear measurement model, an unscented Kalman filter is also used. This paper shows the performance improvement using the magnetic measurement and the benefit of an unscented Kalman filter in simulation.