Accession Number : ADA329043

Title :   Hybrid Neighboring-Optimal-Control and Lambert-Based Interceptor Boost-Phase Guidance,

Corporate Author : NAVAL SURFACE WARFARE CENTER DAHLGREN DIV VA

Personal Author(s) : Lawton, John A. ; Martell, Craig A.

PDF Url : ADA329043

Report Date : 1997

Pagination or Media Count : 9

Abstract : Finding guidance methods that efficiently and effectively handle the problem of directing the boost-phase portion of an exoatmospheric tactical ballistic missile interceptor is an active area of research. This paper presents a candidate method that is a hybrid combination of three algorithms. The chief method, used throughout the majority of the flight, is a minimum-time neighboring optimal control scheme. As demonstrated through Monte Carlo simulations, perturbations in the predicted intercept point (caused by boost-phase updates of the target state estimate received from an exogenous radar) are corrected for in a smooth manner which preserves performance. Even large corrections are handled with low angles of attack, and less than one percent changes in burnout velocity relative to theoretical open-loop optimal control values. Near the end of the booster burn, the guidance scheme switches over to two Lambert-based guidance methods, which have the effect of taking out residual velocity errors, thus putting the interceptor on a nearly exact intercept path to the latest estimate of the target trajectory. The total scheme, while being somewhat computationally complex in pre-deployment development, is actually computationally simple for on-board computations, and has a small computer memory requirement. Therefore, the robust performance combined with the light computational burden provided by this hybrid algorithm make it a competitive candidate for boost-phase interceptor guidance.

Descriptors :   *BALLISTIC MISSILE INTERCEPT SYSTEMS, *MIDCOURSE GUIDANCE, ALGORITHMS, OPTIMIZATION, BOOST PHASE, FLIGHT CONTROL SYSTEMS, ANGLE OF ATTACK, INTERCEPTORS, FLIGHT PATHS, TERMINAL GUIDANCE, THEATER MISSILE DEFENSE.

Subject Categories : Antimissile Defense Systems
      Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE