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International Journal of Aerospace Engineering
Volume 2018 (2018), Article ID 7403639, 13 pages
https://doi.org/10.1155/2018/7403639
Research Article

A Two-Phased Guidance Law for Impact Angle Control with Seeker’s Field-of-View Limit

1Key Laboratory of Dynamic and Control of Flight Vehicle of the Ministry of Education, School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, China
2Beijing Electro-Mechanical Engineering Institute, Beijing 100071, China

Correspondence should be addressed to Jie Guo; nc.ude.tib@1891eijoug

Received 25 July 2017; Revised 27 October 2017; Accepted 12 November 2017; Published 25 March 2018

Academic Editor: Hikmat Asadov

Copyright © 2018 Haoqiang Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A two-phased guidance problem with terminal impact angle constraints and seeker’s field-of-view limit is addressed in this paper for a missile against a nonmaneuvering incoming target. From the conventional PN guidance without any constraints, it is found that satisfying the impact angle constraint causes a more curved missile trajectory requiring a large look angle. To avoid the look angle exceeding the seeker’s physical limit, a two-phased look angle control guidance scheme with the terminal constraint is introduced. The PN-typed guidance law is designed for each guidance phase with a specific switching condition of line-of-sight. The proposed guidance law is comprised of two types of acceleration commands: the one in the initial phase which aims at controlling the missile’s look angle to reach the limit and the other for final phase which is produced by switching the navigation gain. The monotonicity of the line-of-sight angle and look angle is analyzed and proved to support the proposed method. To evaluate the specific navigation gains for both initial and final phases, the scaling coefficient between them is discussed by solving a quadratic equation with respect to the initial navigation gain. To avoid a great abrupt acceleration change at the switching instant, a minimum coefficient is chosen. Extensive simulations are performed to validate the efficiency of the proposed approach.