Guidance of air-to-air agile missiles

Abstract

This thesis studies the effective guidance of engaging a target for air-to-air agile missiles. The agile missiles have ‘lock-on after launch’ ability and engage the target in the rear hemisphere relative to the launch aircraft. Therefore, it is important to ensure that agile missiles have enough velocity after agile turn phase in order to intercept the target. To enhance missiles’ performance during the agile turn phase, optimal control theory is applied to get the maximized terminal velocity. In order to analyze the characteristics of the optimal solutions, simulations are conducted on a two dimensional plane with three stages: launch and initial flight

agile turn

and terminal homing. For the launch and initial flight stage, numerical solution is obtained from the missile dynamics with thrust model. This phase is essential because the missile has to start maneuvering when it secures a certain safety distance from the launch aircraft. The agile turn stage is the main topic of this research. The agile missile rapidly changes its flight path angle in this phase. ‘Time-fixed terminal velocity maximization problem’ is solved by the Radau pseudospectral numerical method. The terminal homing phase is for intercepting the target. The proportional navigation guidance is applied for the guidance law. The validity of ‘terminal velocity maximization in agile turn phase’ problem is discussed by comparing the final velocities of different agile turn time missiles.