Continuous robust guidance law for intercepting maneuvering targets

This paper documents a new guidance law for tactical missiles to intercept maneuvering targets. By incorporating linear and fractional power nonlinear terms, a faster convergent and chatter-free acceleration command is derived. With the aid of Lyapunov stability criteria, we prove that the line-of-sight angular rate can converge to a small region around the origin in finite time. Since the target maneuver cannot be obtained or measured in real applications, a nonlinear finite time convergence disturbance observer for target maneuver estimation is introduced and a composite guidance law with finite time convergence is presented to improve the overall performance. Theoretical analysis and numerical simulations demonstrate the effectiveness of the proposed method.