Abstract:

In order to achieve the interception of the high speed maneuvering target with quasiparallel approaching state, a nonsingular fast terminal secondorder sliding mode guidance law with finite time convergence is proposed with the consideration of the dynamics of missile’s autopilot. Firstly, a novel guidance law is designed based on the terminal sliding mode control and the secondorder sliding mode control. Secondly, the finitetime convergent character and stability of the proposed guidance law are analyzed and proved subsequently with the finite time convergent control theorem. Thirdly, in order to restrain the measurement noise and estimate the line of sight (LOS) angular rate, a finite time convergent differential tracker is designed, which is combined with the extended state observer to estimate the uncertain terms. Simulation results show that the designed differentiator converges faster with high estimation precision and has stronger antiinterference ability. The designed guidance law makes the LOS rate angular convergence in finite time, which provides necessary conditions for the direct collision.