Two-Dimensional Continuous Terminal Interception Guidance Law With Predefined Convergence Performance

This paper derives a new terminal homing guidance law for missiles to intercept noncooperative maneuvering targets subject to the constraint of terminal line-of-sight angle. The new guidance law avoids abrupt and large changes in guidance commands, while allows the control gains to be determined analytically or chosed loosely to ease the design of guidance law. This is achieved by combining the advantages of sliding mode, prescribed performance, and inertial delay controllers. The prescribed performance controller is designed by a new two-phased prescribed performance function with an improved continuous dynamic property, which drives the predefined state error-based sliding mode variable to a small residual set around zero. The inertial delay controller is adopted to suppress the system uncertainty. Thus, the new guidance law yields continuous guidance commands over the entire terminal homing phase while eliminating abrupt and large changes in the initial phase, resulting from the initial state errors in the prescribed performance function. The newly proposed guidance law improves the prescribed performance control that dominates the gains of the proposed guidance law. Theoretical analyses and numerical simulations are conducted to verify the robustness and preciseness of the proposed guidance law.