Homogenous observer-based second-order sliding mode guidance law

A new homogenous observer-based finite-time convergent guidance law is proposed to intercept maneuvering targets without line-of-sight (LOS) angular rate information. The presented formulation is obtained via a combination of homogenous theory and second-order sliding mode (SOSM) method. Different from some existing observers, the proposed algorithm can estimate the lumped uncertainty and the LOS angular rate in an integrated manner. By virtue of the principle of SOSM, the undesired chattering is mitigated significantly without any sacrifice in performance. Detailed stability shows that the LOS angular rate can be stabilized in a small region around zero in finite time. Numerical simulations with some comparisons are carried out to demonstrate the superiority of the proposed method.