טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentTan Zheng Wen
SubjectOptimal Target Defensive Strategies Against Multiple
Pursuers
DepartmentDepartment of Aerospace Engineering
Supervisors Professor Tal Shima
Dr. Robert Fonod


Abstract

In this thesis, a novel cooperative defensive guidance concept is proposed when a target team is engaged by multiple pursuers. Instead of employing classical strategies such as performing evasive maneuvers or deploying defender missiles, the targets lure their pursuing missiles into collision. The thesis first considers a general n-on-m engagement where m Î {ℤ| m ≥ 1} and n Î {ℤ| n m, n ≠ 1}. Results from limit case analyses on the n-on-1 and n-on-2 engagements are extended heuristically to a general n-on-m engagement to highlight the challenges involved in developing a linear guidance strategy for the latter case before we focus on deriving the optimal cooperative guidance law specifically for a 2-on-2 engagement. The guidance law for the 2-on-2 engagement is solved using State Dependent Riccati Equation method. Linearized kinematics and arbitrary-order linear adversaries' dynamics are assumed in the guidance law derivation. Imperfect information is assumed on the relative states and the guidance laws employed by the missile pair. Guidance strategies that the pursuing missiles may employ are assumed to belong to a finite set of known linear guidance laws. In addition to the proposed cooperative defensive strategy, a decentralized estimation scheme based on the multiple model adaptive estimation approach is also derived. Guidance law and estimation performance for a 2-on-2 engagement are demonstrated using nonlinear simulations. Simulation results show the viability of the proposed guidance law and highlight the sensitivity of the guidance law to range measurement accuracy.