Elliptical trajectory based three-dimensional impact angle control guidance

A guidance law with terminal impact angle constraint for three-dimensional intercept have been presented for missile. Elliptical trajectory is proposed to satisfy desired impact angle, which is generated by two positions of missile and target, two flight path angles of missile and target and minimal eccentricity condition. Minimal eccentricity condition makes the roundest trajectory of missile. To track this designated elliptical trajectory, pitch acceleration commands are designed by error between sum of flight path angle and line of sight angle of missile and sum of same angles of real trajectory. Heading angle is considered similarly to pitch angle, to make missile converge to the plane where designated ellipse exists. Simulation results demonstrate that three-dimensional elliptic guidance satisfies desired impact angle.