A Backstepping-Based Guidance Law for an Exoatmospheric Missile With Impact Angle Constraint

A novel method of exoatmospheric guidance law design is proposed in this paper. By analyzing the nonlinear kinematic equations, a class of nominal motions that requires no maneuver effort can be derived for a nose jet control missile. A unique time to go can be solved online from the equations derived from the property of the nominal motion to guarantee a perfect interception. With the time to go determined, the nominal heading angle and heading angular rate can be obtained to impose an impact angle constraint. A backstepping-based continuous three-order finite-time guidance law is designed such that the heading angle tracking is guaranteed. The superiority of the guidance law is demonstrated by a series of simulation results.