Finite Time Convergence Guidance Law Accounting for Second-Order Dynamics of Missile Autopilots

Accounting for the missile autopilot as second-order dynamics,a guidance law with finite time convergence is designed using the sliding mode control method and finite time convergence control theory.The high-order derivatives of the line of sight angle are avoided in the expression of guidance law so that it can be implemented in practical applications.The proposed guidance law is effective in compensating the bad influence of the autopilot lag on guidance accuracy.In simulations of intercepting non maneuvering targets and targets with sinusoidal acceleration respectively,the guidance law is compared with the adaptive sliding mode guidance law in the presence of missile autopilot lag.Simulation results show that the proposed guidance law is able to guide a missile to accurately intercept a maneuvering target,even if it escapes in a great and fast maneuver and the autopilot has a relatively large lag.