Accession Number : ADA193377

Title :   Optimum-Path-to-Go Guidance of Command Adjusted Trajectory Projectiles.

Descriptive Note : Final technical rept. 29 Jul 87-28 Jan 88,

Corporate Author : BARRON ASSOCIATES INC STANARDSVILLE VA

Personal Author(s) : Barron, Roger L ; Elder, John F , IV

PDF Url : ADA193377

Report Date : 22 Jan 1988

Pagination or Media Count : 123

Abstract : Execution of optimal guidance and control algorithms in real time with a microprocessor is feasible using polynomial networks to store, in compact and almost instantly retrievable form, information about a large number of pre-computed optimum two-point boundary-value (TPBV) trajectory solutions. The mathematical basis for computing these optimum solutions has been derived in this SBIR Phase I work using the calculus of variations to obtain adjoint differential equations that are initialized for the TPBV solution. Historically, these initializations have usually necessitated iterative computations because the adjoint equations are not analytically integrable. It is shown that polynomial networks fitted, off-line, to a data base of optimum trajectories can provide the appropriate initializations in real time. These polynomial networks offer optimum-path-to-go (OPTG) and target motion prediction capabilities that can significantly improve performance of maneuverable projectiles, particularly in cases of thruster impulse limitations and substantial uncertainties about target behavior. This report presents the derivation of the governing variational equations, a simulation for three-degree-of-freedom trajectory guidance analyses of command adjusted trajectory (CAT) projectiles engaging maneuvering targets, and results for a 120mm CAT projectile. The results show that the blended guidance law has a smaller miss distance and greater divert capability than the baseline guidance, and that pure OPTG guidance requires fewer divert squib firings than the baseline guidance.

Descriptors :   *GUIDANCE, *GUIDED PROJECTILES, *PROJECTILE TRAJECTORIES, ALGORITHMS, BASE LINES, CALCULUS OF VARIATIONS, COMPUTATIONS, CONTROL, DATA BASES, DIFFERENTIAL EQUATIONS, ELECTRIC IGNITERS, ELECTRIC PRIMERS, EQUATIONS, ITERATIONS, LIMITATIONS, MANEUVERABILITY, MICROPROCESSORS, MISS DISTANCE, MOVING TARGETS, NETWORKS, OPTIMIZATION, POLYNOMIALS, MATHEMATICAL PREDICTION, PULSES, REAL TIME, SIMULATION, SOLUTIONS(GENERAL), THRUSTERS, BOUNDARY VALUE PROBLEMS, COMMAND GUIDANCE, CONTROL THEORY

Subject Categories : Navigation and Guidance
      Ballistics
      Guided Munitions

Distribution Statement : APPROVED FOR PUBLIC RELEASE