Robust finite-time line-of-sight angular rate estimation in missile guidance

This paper documents a robust finite-time line-of-sight angular rate estimation in missile guidance. Through geometric homogeneity and Lyapunov theories, it is shown that the observer estimation errors can converge into a bounded nonzero residual set in finite time and the upper bound can be lowered by parameter tunings. For estimation performance improvement, the sliding mode gains are also determined theoretically. With the help of these gains, it is proved that the observer estimation errors can converge to zero in finite time. Detailed simulation results with some comparisons are performed to validate the proposed formulation.