Adaptive terminal guidance for hypervelocity impact in specified direction

The problem of guiding a hypersonic gliding vehicle in the terminal phase to a target location is considered. In addition to the constraints on its final position coordinates, the vehicle must also impact the target from a specified direction with very high precision. The proposed three-dimensional guidance laws take simple proportional forms. The analysis establishes that with appropriately selected guidance parameters the three-dimensional guided trajectory will satisfy these impact requirements. We provide the conditions for the initial online selection of the guidance law parameters for the given impact direction requirement. The vehicle dynamics are explicitly taken into account in the realization of guidance commands. To ensure high accuracy in the impact angle conditions in an operational environment, we develop closed-loop nonlinear adaptation laws for the guidance parameters. We present the complete guidance logic and associated analysis. Simulation results are provided to demonstrate the effectiveness and accuracy of the proposed terminal guidance approach.