Biased proportional navigation guidance for impact angle control with extension to three-dimensional engagements


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: KORAY SAVAŞ ERER

Danışman: MUSTAFA KEMAL ÖZGÖREN

Özet:

This work shows that the impact angle can be controlled by means of bias addition to pure proportional navigation guidance commands. After obtaining the closed-form solution of the nonlinear differential equations governing the engagement kinematics between a pursuer and a stationary target, it is shown that the proposed strategy corresponds to the optimal solution in the linear domain. Three alternative guidance laws that do not require the time to go are proposed. The first law constitutes a two-phased approach, where the bias is removed after obtaining proper pursuit conditions. The second law, which makes use of the range-to-go information, and the third law, which leads to an exponentially decaying error profile, are single-phased approaches that do not suffer from the open-loop nature of the first one in its second phase. The framework of this study allows the treatment of both the look angle and the acceleration constraints in such a way that the impact angle capacity corresponding to any engagement geometry can be analyzed. In addition to a complete but impractical formulation, a feasible constrained guidance solution is presented. A single-gain range observer that addresses the observability issue in a convenient manner is formulated to supplement the trajectory shaping effort. The case of moving targets is dealt with by means of constructing the collision triangle. Two different schemes are considered based on the rotations of the absolute and relative velocity vectors. The plane-pursuit midcourse guidance method proposed to confine a general engagement scenario to a single plane facilitates the extension to three-dimensional engagements.