Three-dimensional nonlinear gravity assisted aiming point guidance

A novel three dimensional aiming point guidance law is presented in this paper, which eliminates the need for gravity compensation, resulting in engagements occurring with zero acceleration commands, in turn leading to smaller overall control effort and an excellent zero effort miss behavior. The conditions necessary for collision in the presence of gravity are derived using model-based prediction and computationally efficient shooting method. This is followed by employing differential-geometric guidance philosophy for achieving collision with the target. The efficacy of the proposed guidance law is then verified using simulation studies for terminal phase ballistic missile interception, and is compared with proportional navigation, aiming point guidance and compensated-weave guidance. Results indicate that the proposed guidance law ensured collision with desired level of accuracy and outperformed the aforementioned guidance laws used for comparison, in terms of miss distance, zero effort miss behavior and control effort. (C) 2018 Elsevier Masson SAS. All rights reserved.