Observerbility analysis of rocket MEMS-INS/GNSS integrated navigation system attitude in classic trajectories

MEMS-INS/GNSS integrated navigation system for artillery launched rockets is taken as the research object. Based on the singular value decomposition of system observability matrix, a new concept, "equivalent singular value", is proposed to test the observability of a system state. The method is used to analyze the observability of Euler angle errors in three kinds of trajectories without maneuver and with pitch and yaw maneuvers. The curves of "equivalent singular value" (observability) of three Euler angles errors are plotted, which illustrate that the roll error observability becomes better when projectile body maneuvers, the pitch angle error observability is mainly related to the acceleration in the axis of the body symmetry, and the azimuth error observability is proportional to horizontal acceleration. The simulation results are consistent with the analysis results.