Real time missile guidance system

摘要

A weak Hamiltonian finite element method is used for iterative computation of missile guidance acceleration commands for maximizing a missile's terminal velocity while satisfying control authority limits and terminal attitude constraints. The guidance acceleration commands include commands for controlling the angle of attack ( alpha ) and the bank angle ( phi ) of the missile. The angle of attack ( alpha ) and bank angle ( phi ) are related to a set of virtual control variables selected to avoid convergence problems when the angle of attack is approximately zero. The preferred control variables are beta 2 and beta 3 such that beta 2=cos phi tan alpha and beta 3=sin phi tan alpha . Iterative convergence is facilitated when control inequality constraint parameters are reached by adjusting iterative solutions between iterations toward satisfaction of the constraints. An approximation to an optimal trajectory is calculated at each guidance cycle during missile flight using data which are revised during each guidance cycle. The revised data include current position data for the target and the current position for the missile. The revised data are taken from the most reliable source currently available, such as on-board target-seeking radar when the target-seeking radar is locked onto the target, uplink data from ground or airborne tracking radar when an uplink is operational, or inertial guidance data. Extracted from the optimal trajectory is an optimal acceleration command for optimally controlling the angle of attack and bank angle of the missile.