Accession Number : AD0675975

Title :   OPTIMAL INTERCEPT GUIDANCE FOR MULTIPLE TARGET SETS,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ELECTRONIC SYSTEMS LAB

Personal Author(s) : Norbutas,Robert J.

Report Date : JAN 1968

Pagination or Media Count : 209

Abstract : The problem of optimally guiding a vehicle to intercept more than one target is investigated. The major contributions are the following: (a) the extension of the variational calculus and two numerical algorithms (steepest-descent and Newton-Raphson) to multiple target set problems; and (b) the design of a suboptimal feedback controller for a specific problem of a vehicle intercepting two targets. The problems considered are in the form of N-point (N > 2) optimal control problems. Application of the calculus of variations results in a set of (N-1) two-point boundary value problems coupled through their boundary conditions. The additional boundary conditions are sets of intermediate transversality conditions in terms of discontinuities in the costate and Hamiltonian that are of the same form as the terminal transversality conditions. The steepest-descent and Newton-Raphson algorithms are extended to handle N-point optimal control problems. The modification of the steepest-descent algorithm involves the computation of an additional influence function for each intermediate state constraint, thereby increasing the computation time required per iteration proportionately. The Newton-Raphson algorithm is found to be inferior to the steepest-descent algorithm for computing optimal two target intercept trajectories because of the difficulty with which it handles free-time problems. Optimal intercept trajectories are computed for a particular two target missile guidance problem. (Author)

Descriptors :   (*INTERCEPT TRAJECTORIES, OPTIMIZATION), MULTIPLE OPERATION, CALCULUS OF VARIATIONS, NUMERICAL METHODS AND PROCEDURES, STEEPEST DESCENT METHOD, ALGORITHMS, TARGETS, BOUNDARY VALUE PROBLEMS, COMPUTER PROGRAMS, TARGETS, GUIDED MISSILES

Distribution Statement : APPROVED FOR PUBLIC RELEASE