Barrier Function-Based Three-Dimensional Guidance for Position-Constrained Interception

This article presents a 3-D adaptive guidance law based on barrier functions (BFs) for position constraint during the interception of a maneuvering target by a laser beam riding steered interceptor. First, a hyperbolic tangent function-based tracking differentiator is used to estimate the unknown target maneuver information, including the line-of-sight angle and rate. Second, considering the effective energy range of the laser beam information field, a fixed distance prescribed performance function is designed to ensure that the system state converges to the predefined region within a limited distance. In addition, a deviation-dependent shift function is developed and integrated with BFs to transform the constrained system into an unconstrained state. Combined with the $\sigma$-modification adaptive law, an output constraint controller is designed using the backstepping strategy to handle arbitrary initial position deviations. Finally, numerical simulations are carried out to demonstrate the effectiveness and superiority of the proposed guidance law.