A new three-dimensional sliding mode guidance law variation with finite time convergence

This paper develops a new three dimensional (3D) guidance law which guarantees the interception of manoeuvring targets in a finite time. The new guidance law accepts the concept that nullifying the line-of-sight (LOS) rate guarantees the interception of the target and its derivation is based on finite time sliding mode guidance. By using a 3D kinematic equation set constructed in a rotating coordinate system, the proposed guidance law alleviates an issue of general 3D guidance caused by the cross coupling effect between pitch and yaw planes. In theoretical analysis, finite time convergence of the new guidance law is proved and compared with that of a practical sliding mode guidance law. Characteristics such as energy consumption and convergence boundary layer are also theoretically analysed. Simulation results demonstrate that the new guidance law effectively intercepts manoeuvring targets in a finite time and analysis results are valid.