2. Optimal Error Dynamics in Missile Guidance

This chapter investigates the optimal convergence pattern of the tracking error that frequently appears in missile guidance problems and proposes an optimal error dynamics for guidance law design to achieve various operational objectives. The proposed optimal error dynamics is derived by solving a linear quadratic optimal control problem through Schwarz’s inequality approach. The properties of the proposed optimal error dynamics are discussed. The significant contribution of the proposed result lies in that it can provide a link between existing nonlinear guidance laws and optimal guidance laws for missile systems. Therefore, the advantages of both techniques can be fully exploited by using the proposed approach: existing nonlinear guidance laws can be converted to their optimal forms and the physical meaning of them can then be easily explained. Four illustration examples, including zero zero-effort-miss (ZEM) guidance, impact angle guidance, impact time control, impact angle control as well as impact angle and impact time control, are provided to show how the proposed results can be applied to missile guidance law design. The performance of the new guidance laws is demonstrated by numerical simulation.